AIM: To examine the underlying mechanisms of erlotinib-induced growth inhibition in hepatocellular carcinoma (HCC). METHODS: Erlotinib-induced alterations in gene expression were evaluated using cDNA array technol...AIM: To examine the underlying mechanisms of erlotinib-induced growth inhibition in hepatocellular carcinoma (HCC). METHODS: Erlotinib-induced alterations in gene expression were evaluated using cDNA array technology; changes in protein expression and/or protein activation due to erlotinib treatment as well as IGF-1-induced EGFR transactivation were investigated using Western blotting. RESULTS: Erlotinib treatment inhibited the mitogen activated protein (MAP)-kinase pathway and signal transducer of activation and transcription (STAT)- mediated signaling which led to an altered expression of apoptosis and cell cycle regulating genes as demonstrated by cDNA array technology. Overexpression of proapoptotic factors like caspases and gadds associated with a down-regulation of antiapoptotic factors like Bcl-2, Bcl-XL or jun D accounted for erlotinib's potency to induce apoptosis. Downregulation of cell cycle regulators promoting the G1/S-transition and overexpression of cyclin-dependent kinase inhibitors and gadds contributed to the induction of a G1/G0-arrest in response to erlotinib. Furthermore, we displayed the transactivation of EGFR-mediated signaling by the IGF-1-receptor and showed erlotinib's inhibitory effects on the receptor-receptor cross talk. CONCLUSION: Our study sheds light on the understanding of the mechanisms of action of EGFR-TK- inhibition in HCC-cells and thus might facilitate the design of combination therapies that act additively or synergistically. Moreover, our data on the pathways responding to erlotinib treatment could be helpful in predicting the responsiveness of tumors to EGFR-TKIs in the future.展开更多
(-)-Epigallocatechin gallate (EGCG), a major polyphenolic constituent of green tea, can inhibit activity of specific receptor tyrosine kinases (RTKs) and related downstream signal transduction pathways, resultin...(-)-Epigallocatechin gallate (EGCG), a major polyphenolic constituent of green tea, can inhibit activity of specific receptor tyrosine kinases (RTKs) and related downstream signal transduction pathways, resulting in the control of unwanted cell proliferation. The epidermal growth factor receptor (EGFR) signaling pathway is one of the most important pathways that regulates growth, survival,proliferation and differentiation in mammalian cells. This review addresses the effects of EGCG on some protein factors involved in the EGFR signaling pathway in a direct or indirect manner. Based on our understanding of the interaction between EGCG and these factors, and based on their structures, EGCG could be used as a lead compound for designing and synthesizing novel drugs with significant biological activity.展开更多
Epidermal growth factor receptor(EGFR) controls a wide range of cellular processes, and aberrant EGFR signaling as a result of receptor overexpression and/or mutation occurs in many types of cancer. Tumor cells in non...Epidermal growth factor receptor(EGFR) controls a wide range of cellular processes, and aberrant EGFR signaling as a result of receptor overexpression and/or mutation occurs in many types of cancer. Tumor cells in non-small cell lung cancer(NSCLC) patients that harbor EGFR kinase domain mutations exhibit oncogene addiction to mutant EGFR, which confers high sensitivity to tyrosine kinase inhibitors(TKIs). As patients invariably develop resistance to TKIs, it is important to delineate the cell biological basis of mutant EGFR-induced cellular transformation since components of these pathways can serve as alternate therapeutic targets to preempt or overcome resistance. NSCLC-associated EGFR mutants are constitutively-active and induce ligandindependent transformation in nonmalignant cell lines. Emerging data suggest that a number of factors are critical for the mutant EGFR-dependent tumorigenicity, and bypassing the effects of TKIs on these pathways promotes drug resistance. For example, activation of downstream pathways such as Akt, Erk, STAT3 and Src is critical for mutant EGFR-mediated biological processes. It is now well-established that the potency and spatiotemporal features of cellular signaling by receptor tyrosine kinases such as EGFR, as well as the specific pathways activated, is determined by the nature of endocytic traffic pathways through which the active receptors traverse. Recent evidence indicates that NSCLCassociated mutant EGFRs exhibit altered endocytic trafficking and they exhibit reduced Cbl ubiquitin ligasemediated lysosomal downregulation. More recent work has shown that mutant EGFRs undergo ligand-independent traffic into the endocytic recycling compartment, a behavior that plays a key role in Src pathway activation and oncogenesis. These studies are beginning to delineate the close nexus between signaling and endocytic traffic of EGFR mutants as a key driver of oncogenicprocesses. Therefore, in this review, we will discuss the links between mutant EGFR signaling and endocytic properties, and introduce potential mechanisms by which altered endocytic properties of mutant EGFRs may alter signaling and vice versa as well as their implications for NSCLC therapy.展开更多
Objective:To explore the effect of hepatocyte growth factor signaling pathway activation on Plasmodium berghei infection.Methods:In this study,hepatocyte growth factor was detected by ELISA and Western blotting assay....Objective:To explore the effect of hepatocyte growth factor signaling pathway activation on Plasmodium berghei infection.Methods:In this study,hepatocyte growth factor was detected by ELISA and Western blotting assay.Hepatocyte injury was detected by FITC-dextran absorption assay,and hepatocyte growth factor expression was shown to be expressed in the same injury cells by immunofluorescence against hepatocyte growth factor.In addition,Activation of hepatocyte growth factor and its receptor signaling pathway was detected with immunoprecipitation and detection of phosphorylation status.Results:It was found that injury of hepatocytes by sporozoite migration induced the secretion of hepatocyte growth factor and it was hepatocyte growth factor that rendered hepatocytes susceptible to Plasmodium sporozoite infection.In addition,hepatocyte infections depended on activation of the hepatocyte growth factor and its receptor signaling pathway.Conclusions:Our results indicate that hepatocyte growth factor and its receptor may possibly be potential targets for new approaches to malaria treatment.展开更多
Objective:persistent hyperinflammation is an important reason for the development of diabetic foot ulcer.Notch signaling is an important signaling pathway involved in the inflammatory response and cell proliferation i...Objective:persistent hyperinflammation is an important reason for the development of diabetic foot ulcer.Notch signaling is an important signaling pathway involved in the inflammatory response and cell proliferation in diabetic foot ulcer rats.This paper aims to explore the effect of Notch signaling on inflammatory factors,chemokines and growth factors through the intervention of Notch signaling in diabetic foot ulcer rats.Methods:the experimental model was made by using high-fat feed combined with streptozotocin(STZ)to cause diabetes,and the experimental model of diabetic foot ulcer was established by constant temperature and constant pressure scald apparatus.The normal ulcer model was used as a control.The intervention controls of the experimental model included normal saline,western medicine growth factor,Notch agonist Jagged1,Notch signaling inhibitor ly-411575,and the intervention of traditional Chinese medicine Zizhu ointment for 7 days.Serum il-1,il-6,TNF-radiation,and il-17 were detected by ELISA.Real-time PCR was used to detect the inflammatory factors,chemokines,and growth factors associated with Notch signaling in wound tissues:tnf-uum,il-1,il-6,il-17,interleukin-8,ip-10,McP-1,TGF-uum,TGF-livelihood.Results:serum levels of il-1,il-6,TNF-radiation and il-17 in diabetic foot ulcer rats were significantly higher than that in normal ulcer rats.The contents of il-1,il-6,TNF-radiation and il-17a in ly-411575 group and Zizhu ointment group were significantly reduced.Real-time PCR results of wound tissue showed that the levels of inflammatory cytokines il-1,il-6,TNF-radiation,il-17 and chemokines ip-10,il-8 and McP-1 in the wound tissue of diabetic foot ulcer rat model were significantly higher than that of normal ulcer model,and the levels of growth factor TGF-exposure were lower than that of normal ulcer model.LY-411575 significantly reduced il-1,il-6,TNF-maxima,il-17,and the chemokines ip-10,il-8,and McP-1 in diabetic foot ulcer rats,and reduced the expression of TGF-,TGF-earth.Jagged1 can increase the expression of TGF--,TGF---,suggesting that inhibition of the Notch signaling pathway can reduce the expression of the inflammatory factors il-1,il-6,TNF--,il-17a,il-8,and the growth factors TGF--,TGF---.Zizhu ointment can reduce the levels of il-1,il-6,TNF-benand,il-17,and the chemokines ip-10,il-8,and McP-1 on the wound surface of diabetic foot rats,and improve the expression of TGF-benand TGF-SUNS.Ly-411575 inhibited the expression of TGF-bento and TGF-promoting of Zizhu ointment.Conclusion:the expression of inflammatory cytokines and chemokines was higher and the expression of growth factors was lower in diabetic foot ulcer rats than in normal ulcer rats.Inhibition of Notch signaling pathway can reduce the expression of inflammatory factors,chemokines and growth factors in experimental model rats,and Notch signaling pathway can promote inflammation and cell proliferation.Zizhu ointment can reduce the levels of inflammatory cytokines and chemokines in diabetic foot ulcer rats,improve the expression of growth factors,and reduce wound inflammation,which may be related to the inhibition of Nocth signal expression.展开更多
Epidermal growth factor receptor(EGFR)signaling has become an importanttarget for drug development becauseEGFR signaling enhances tumor cell proliferation,migration,and invasion and inhibits apoptosis.However,theresul...Epidermal growth factor receptor(EGFR)signaling has become an importanttarget for drug development becauseEGFR signaling enhances tumor cell proliferation,migration,and invasion and inhibits apoptosis.However,theresults of clinical trials using EGFR inhibitors in patients with solid tumors have been disappointing.Here,wereport a protective effect of the EGFR inhibitors AG1478 and PD153035 against cell death induced by acute hy-poxia,which contrasts with their proapoptotic effects under normoxia.Under hypoxic conditions,both agents re-展开更多
BACKGROUND Colorectal cancer(CRC)is an extremely malignant tumor with a high mortality rate.Little is known about the mechanism by which forkhead Box q1(FOXQ1)causes CRC invasion and metastasis through the epidermal g...BACKGROUND Colorectal cancer(CRC)is an extremely malignant tumor with a high mortality rate.Little is known about the mechanism by which forkhead Box q1(FOXQ1)causes CRC invasion and metastasis through the epidermal growth factor receptor(EGFR)pathway.AIM To illuminate the mechanism by which FOXQ1 promotes the invasion and metastasis of CRC by activating the heparin binding epidermal growth factor(HB-EGF)/EGFR pathway.METHODS We investigated the differential expression and prognosis of FOXQ1 and HB-EGF in CRC using the Gene Expression Profiling Interactive Analysis(GEPIA)website(http://gepia.cancer-pku.cn/index.html).Quantitative real-time polymerase chain reaction(qRT-PCR)and Western blotting were used to detect the expression of FOXQ1 and HB-EGF in cell lines and tissues,and we constructed a stable lowexpressing FOXQ1 cell line and verified it with the above method.The expression changes of membrane-bound HB-EGF(proHB-EGF)and soluble HB-EGF(sHB-EGF)in the lowexpressing FOXQ1 cell line were detected by flow cytometry and ELISA.Western blotting was used to detect changes in the expression levels of HB-EGF and EGFR pathway-related downstream genes when exogenous recombinant human HB-EGF was added to FOXQ1 knockdown cells.Proliferation experiments,transwell migration experiments,and scratch experiments were carried out to determine the mechanism by which FOXQ1 activates the EGFR signaling pathway through HB-EGF,and then to evaluate the clinical relevance of FOXQ1 and HB-EGF.RESULTS GEPIA showed that the expression of FOXQ1 in CRC tissues was relatively high and was related to a lower overall survival rate.PCR array results showed that FOXQ1 is related to the HB-EGF and EGFR pathways.Knockdown of FOXQ1 suppressed the expression of HB-EGF,and led to a decrease in EGFR and its downstream genes AKT,RAF,KRAS expression levels.After knockdown of FOXQ1 in CRC cell lines,cell proliferation,migration and invasion were attenuated.Adding HB-EGF restored the migration and invasion ability of CRC,but not the cell proliferation ability.Kaplan–Meier survival analysis results showed that the combination of FOXQ1 and HB-EGF may serve to predict CRC survival.CONCLUSION Based on these collective data,we propose that FOXQ1 promotes the invasion and metastasis of CRC via the HB-EGF/EGFR pathway.展开更多
The epidermal growth factor receptor (EGFR) is a member of the ErbB/EGFR family, including EGFR/Herl, ErbB2/Her2, ErbB-3/Her3, and ErbB-4/Her4. EGFR exerts its effects through the receptor tyrosine kinase phosphoryl...The epidermal growth factor receptor (EGFR) is a member of the ErbB/EGFR family, including EGFR/Herl, ErbB2/Her2, ErbB-3/Her3, and ErbB-4/Her4. EGFR exerts its effects through the receptor tyrosine kinase phosphorylation and activation of important downstream signaling pathways in normal and neoplastic cells, mainly the Ras GTPase/MAP kinase (MAPK), STAT3, and phosphatidylinositide 3 kinase-AKT pathways. EGFR deregulation is common in malignant glioma, especially primary glioblastoma, and exists in three forms: gene overexpression (amplification), autocrine effects of EGFR activation, and activating receptor mutation (EGFRvlII). However, some EGFR abnormalities have also been found in low-grade gliomas, including the nuclear localization of EGFR, expression in the microfoci of anaplastic transformation, and association with neovascularization in the mesenchyma of the glioma, which suggests that some unknown EGFR-related mechanisms are possibly responsible for its central role in the initiation and progression of malignant glioma. Uncovering these mechanisms will have potential value in the development of radio- therapy, chemotherapy, and EGFR-targeted therapy for glioma.展开更多
Fibroblast growth factor receptors(FGFRs) regulate a variety of cellular functions, from embryogenesis to adult tissue homeostasis. FGFR signaling also plays significant roles in the proliferation, invasion, and survi...Fibroblast growth factor receptors(FGFRs) regulate a variety of cellular functions, from embryogenesis to adult tissue homeostasis. FGFR signaling also plays significant roles in the proliferation, invasion, and survival of several types of tumor cells. FGFR-induced alterations, including gene amplification, chromosomal translocation, and mutations, have been shown to be associated with the tumor initiation and progression of gastric cancer, especially in diffuse-type cancers. Therefore, the FGFR signaling pathway might be one of the therapeutic targets in gastric cancer. This review aims to provide an overview of the role of FGFR signaling in tumorigenesis, tumor progression, proliferation, and chemoresistance. We also discuss the accumulating evidence that demonstrates the effectiveness of using clinical therapeutic agents to inhibit FGFR signaling for the treatment of gastric cancer.展开更多
The effect of thyrosine kinase, calmodulin and voltage-dependent Ca 2+ channel on the proliferation of hepatoma cells induced by EGF was studied. Hepatoma cell line SMMC7721 was cultured in RPMI1640 serum-free me...The effect of thyrosine kinase, calmodulin and voltage-dependent Ca 2+ channel on the proliferation of hepatoma cells induced by EGF was studied. Hepatoma cell line SMMC7721 was cultured in RPMI1640 serum-free medium. DNA synthesis rate of hepatoma cells was measured by 3H-TdR incorporation. 10 -9 mol/L EGF could significantly stimulate the proliferation of hepatoma cells (P<0.05), and this effect might be significantly inhibited by tyrosine kinase inhibitor (P<0.001). Calmodulin inhibitor W-7 had no effect on the basic phase of cultured hepatoma cells (P> 0.05), but it had very significantly inhibitory effect on the proliferation of hepatoma cells induced by EGF (P<0.001). Voltage-dependent Ca 2+ channel inhibitor Varapamil had no inhibition on the proliferation of hepatoma cells induced by EGF (P>0.05). It had no effect on the basic phase of cultured hepatoma cells (P>0.05). It is suggested that tyrosine kinase and Ca 2+-calmodulin-dependent pathway may play a critical role on the proliferation of heptoma cells induced by EGF, and voltage-dependent Ca 2+ channel is independent of the effect of EGF.展开更多
Objective:To investigate the effects of miR-124 overexpression on inflammatory factors and epidermal growth factor in rats with gastric precancerous lesions by modulating the Wnt/β-catenin signaling pathway.Methods:E...Objective:To investigate the effects of miR-124 overexpression on inflammatory factors and epidermal growth factor in rats with gastric precancerous lesions by modulating the Wnt/β-catenin signaling pathway.Methods:Eighty SPF-grade Wistar rats were selected as the research subjects.After adaptive feeding,they were divided into 4 groups using a random number table method.The control group was fed a regular diet,while the model group,low expression group,and overexpression group of rats were treated with N-methyl-N’-nitro-N-nitrosoguanidine to establish a model of gastric cancer precancerous lesions.After successful modeling,the control group and model group rats were injected intraperitoneally with 0.9%sodium chloride solution,the low-expression group rats were injected intraperitoneally with miR-124-5p inhibitor,and the over-expression group rats were injected intraperitoneally with miR-124-5p mimic.After 8 weeks of continuous injection,the levels of miR-124,Wnt/β-catenin signaling pathway-related proteins,inflammatory factors,and epidermal growth factor were observed and compared among the four groups of rats.Results:The differences in the relative expression of miR-124 among the four groups of rats were statistically significant(P<0.05);the differences in the expression of Wnt protein andβ-catenin protein among the four groups of rats were statistically significant(P<0.05),and the expression of Wnt protein andβ-catenin protein in the overexpression group was significantly higher than that of the control group,and significantly lower than that in the model group and the low-expression group;the levels of IL-1β,IL-6,and TNF-αof rats in the four groups of rats IL-1β,IL-6 and TNF-αlevels were statistically different(P<0.05),and the levels of IL-1β,IL-6 and TNF-αin rats in the overexpression group were higher than those in the model group and significantly lower than those in the model group and the low-expression group(P<0.05);the differences in the levels of EGF,HER1 and HER2 among the four groups of rats were statistically different(P<0.05),and the levels of EGF levels were higher than those of the control group,and EGF and HER1 were significantly lower than those of the model and low expression groups(P<0.05).Conclusion:Mi R-124 overexpression helps to reduce gastric mucosal damage and inflammatory response in rats with gastric precancerous lesions,and its mechanism of action may be linked to the inhibition of the Wnt/β-catenin signaling pathway.展开更多
Objective:To observe the expression changes of inflammatory markers TGF-β1,Smad3 and IL-6 in patients with atrial fibrillation(AF),and to explore the significance of TGF-β1 signaling pathway in the structural remode...Objective:To observe the expression changes of inflammatory markers TGF-β1,Smad3 and IL-6 in patients with atrial fibrillation(AF),and to explore the significance of TGF-β1 signaling pathway in the structural remodeling of AF.Methods:The expression of TGF-β1,Smad3 and IL-6 in 50 cases with AF and 30 normal cases were detected by RT-PCR and ELISA.Results:The TGF-β1,Smad3 and IL-6 mRNA and protein expression levels in patients with AF were significantly higher than that in the control group(P<0.05),but there was no significantly different between the paroxysmal AF group and the persistent AF group(P>0.05).The TGF-β1mRNA expression in the≥50 years subgroup was significantly higher than that in the<50years subgroups,and it was higher in the NYHAⅢsubgroup than in theⅠ/Ⅱgrade subgroup.It was also higher in the left ventricular ejection fraction(LVEF)<50%subgroup than in LVEF≥50%group,and it was significantly higher in the AF time≥36 months subgroup than that in<36months subgroup(P<0.05).The Smad3 and IL-6 expressions in the in the LVEF<50%subgroup were both high that than that in LVEF≥50%group,and higher in the AF time≥36 months subgroup than that in<36 months subgroup(P<0.05).There were a positive correlation between TGF-β1,Smad3 and IL-6(r=0.687,r=0.547).There were also a positive correlation between Smad3 and IL-6 mRNA(r=0.823).Conclusions:AF is associated with inflammation,and the inflammation is also involved in the fibrillation and sustain of AF.The TGF-β1 signal pathway may be involved in the process of atrial structural remodeling in patients with AF,and iss related with the occurrence and maintenance of AF.展开更多
Background: Previous research suggested that insulin-like growth factor binding protein related protein 1(IGFBPrP1), as a novel mediator, contributes to hepatic fibrogenesis. Matrix metalloproteinases(MMP) and tissue ...Background: Previous research suggested that insulin-like growth factor binding protein related protein 1(IGFBPrP1), as a novel mediator, contributes to hepatic fibrogenesis. Matrix metalloproteinases(MMP) and tissue inhibitors of metalloproteinases(TIMP) play an essential role in hepatic fibrogenesis by regulating homeostasis and remodeling of the extracellular matrix(ECM). However, the interaction between IGFBPrP1 and MMP/TIMP is not clear. The present study was to knockdown IGFBPrP1 to investigate the correlation between IGFBPrP1 and MMP/TIMP in hepatic fibrosis. Methods: Hepatic fibrosis was induced by thioacetamide(TAA) in mice. Knockdown of IGFBPrP1 expression by ultrasound-targeted microbubble destruction-mediated CMB-shRNA-IGFBPrP1 delivery, or inhibition of the Hedgehog(Hh) pathway by cyclopamine treatment, was performed in TAA-induced liver fibrosis mice. Hepatic fibrosis was determined by hematoxylin and eosin and Sirius red staining. Hepatic expression of IGFBPrP1, α-smooth muscle actin( α-SMA), transforming growth factor β 1(TGF β1), collagen I, MMPs/TIMPs, Sonic Hedgehog(Shh), and glioblastoma family transcription factors(Gli1) were investigated by immunohistochemical staining and Western blotting analysis. Results: We found that hepatic expression of IGFBPrP1, TGF β1, α-SMA, and collagen I were increased longitudinally in mice with TAA-induced hepatic fibrosis, concomitant with MMP2/TIMP2 and MMP9/TIMP1 imbalance and Hh pathway activation. Knockdown of IGFBPrP1 expression, or inhibition of the Hh pathway, reduced the hepatic expression of IGFBPrP1, TGF β1, α-SMA, and collagen I and re-established MMP2/TIMP2 and MMP9/TIMP1 balance. Conclusions: Our findings suggest that IGFBPrP1 knockdown attenuates liver fibrosis by re-establishing MMP2/TIMP2 and MMP9/TIMP1 balance, concomitant with the inhibition of hepatic stellate cell activation, down-regulation of TGF β1 expression, and degradation of the ECM. Furthermore, the Hh pathway mediates IGFBPrP1 knockdown-induced attenuation of hepatic fibrosis through the regulation of MMPs/TIMPs balance.展开更多
Cancer treatments are rapidly changing.Curative treatment for oesophageal adenocarcinoma currently involves surgery and cytotoxic chemotherapy or chemoradiotherapy.Outcomes for both regimes are generally poor as a res...Cancer treatments are rapidly changing.Curative treatment for oesophageal adenocarcinoma currently involves surgery and cytotoxic chemotherapy or chemoradiotherapy.Outcomes for both regimes are generally poor as a result of tumor recurrence.We have reviewed the key signalling pathways associated with oesophageal adenocarcinomas and discussed the recent trials of novel agents that attempt to target these pathways.There are many trials underway with the aim of improving survival in oesophageal cancer.Currently,phase 2 and 3 trials are focused on MAP kinase inhibition,either through inhibition of growth factor receptors or signal transducer proteins.In order to avoid tumor resistance,it appears to be clear that targeted therapy will be needed to combat the multiple signalling pathways that are in operation in oesophageal adenocarcinomas.This may be achievable in the future with the advent of gene signatures and a combinatorial approach.展开更多
AIM: To investigate the effect of microR NA on insulinlike growth factor binding protein-3(IGFBP-3) and hence on insulin-like growth factor-Ⅱ(IGF-Ⅱ) bioavailability in hepatocellular carcinoma(HCC).METHODS: Bioinfor...AIM: To investigate the effect of microR NA on insulinlike growth factor binding protein-3(IGFBP-3) and hence on insulin-like growth factor-Ⅱ(IGF-Ⅱ) bioavailability in hepatocellular carcinoma(HCC).METHODS: Bioinformatic analysis was performed using microrna.org, DIANA lab and Segal lab softwares. Total RNA was extracted from 23 HCC and 10 healthy liver tissues using mir Vana mi RNA Isolation Kit. microR NA-17-5p(miR-17-5p) expression was mimicked and antagonized in Hu H-7 cell lines using Hi Per Fect Transfection Reagent, then total RNA was extracted using Biozol reagent then reverse transcribed into cD NA followed by quantification of mi R-17-5p and IGFBP-3 expression using Taq Man real-time quantitative PCR. Luciferase reporter assay was performed to validate the binding of miR-17-5p to the 3'UTR of IGFBP-3. Free IGF-Ⅱ protein was measured in transfected Hu H-7 cells using IGF-Ⅱ ELISA kit. RESULTS: Bioinformatic analysis revealed IGFBP-3 as a potential target for miR-17-5p. Screening of miR-17-5p and IGFBP-3 revealed a moderate negative correlation in HCC patients, where mi R-17-5p was extensively underexpressed in HCC tissues(P = 0.0012), while IGFBP-3 showed significant upregulation in the same set of patients(P = 0.0041) compared to healthy donors. Forcing mi R-17-5p expression in Hu H-7 cell lines showed a significant downregulation of IGFBP-3 mR NA expression(P = 0.0267) and a significant increase in free IGF-Ⅱ protein(P = 0.0339) compared to mock untransfected cells using unpaired t-test. Luciferase assay validated IGFBP-3 as a direct target of mi R-17-5p; luciferase activity was inhibited by 27.5% in cells co-transfected with miR-17-5p mimics and the construct harboring the wild-type binding region 2 of IGFBP-3 compared to cells transfected with this construct alone(P = 0.0474).CONCLUSION: These data suggest that regulating IGF-Ⅱ bioavailability and hence HCC progression can be achieved through targeting IGFBP-3 via manipulating the expression of miR NAs.展开更多
Objective To determine whether transforming growth factor betal (TGF-β1)/Smad signaling pathway mediates p53-dependent apoptosis in hepatoma cell lines.Methods Three human hepatic carcinoma cell lines, HepG2, Huh-7, ...Objective To determine whether transforming growth factor betal (TGF-β1)/Smad signaling pathway mediates p53-dependent apoptosis in hepatoma cell lines.Methods Three human hepatic carcinoma cell lines, HepG2, Huh-7, and Hep3B, were used in this study.TGF-β1-induced apoptosis in hepatic carcinoma cell lines was analyzed using TUNEL assay.For identifying the mechanism of apoptosis induced by TGF-β1, cell lines were transfected with a TGF-β1-inducible luciferase reportor plasmid containing Smad4 binding elements.After transfection, cells were treated with TGF-β1, then assayed for luciferase activity.Results The apoptosis rate of HepG2 cell lines (48.51%± 8.21%) was significantly higher than control ( 12.72%±2.18%, P<0.05).But TGF-β1 was not able to induce apoptosis of Huh-7 and Hep3B cell lines.The relative luciferase activity of TGF-β1-treated HepG2 cell lines (4.38) was significantly higher than control (1.00, P< 0.05).But the relative luciferase activity of TGF-β1-treated Huh-7 and Hep3B cell lines less increased compared with control.Conclusions HepG2 cells seem to be highly susceptible to TGF-β1-induced apoptosis compared with Hep3B and Huh-7 cell lines.Smad4 is a central mediator of TGF-β1 signaling transdution pathway.TGF-β1/Smad signaling pathway might mediate p53-dependent apoptosis in hepatoma cell lines.展开更多
The present study characterized the nerve growth factor (NGF)-mediated regulation of tau protein expression and transcription in IMR32 human neuroblastoma cells. Treatment of IMR32 cells with 50 ng/mL NGF resulted in ...The present study characterized the nerve growth factor (NGF)-mediated regulation of tau protein expression and transcription in IMR32 human neuroblastoma cells. Treatment of IMR32 cells with 50 ng/mL NGF resulted in increased levels of specific tau protein isoforms. A 550 bp fragment of the tau promoter was cloned and treatment of transfected IMR32 and PC12 cells with NGF also resulted in increased promoter activation, suggesting that the NGF-mediated increase in tau isoforms is regulated, at least in part, at the level of transcription. Pretreatment with the MAP kinase inhibitor U0126 or the PKC inhibitor bisindolylmaleimide 1 (BIS-1) attenuated the NGF-mediated increase in tau transcription, indicating that the NGF-mediated activation of the MAP kinase and PKC signaling pathways modulate tau transcription. Pre-treatment of cells with the Akt inhibitor, LY294002 or with NOS inhibitors Nω-nitro-L-arginine methylester (L-NAME) or s-methylisothiourea (S-MIU) had no effect on the NGF-mediated increase in tau promoter activation, suggesting that NO and the NGF-Akt signaling pathway do not modulate tau transcription. Taken together, these data demonstrate that NGF increases the levels of multiple human tau isoforms in IMR32 cells which may result, at least in part, from NGF-mediated PKC and MAP kinase-induced tau transcription.展开更多
BACKGROUND The transforming growth factor β(TGFβ) signaling pathway plays a crucial role in the development of liver fibrosis by activating TGFβ type Ⅱ receptor(TGFβR2), followed by the recruitment of TGFβR1 fin...BACKGROUND The transforming growth factor β(TGFβ) signaling pathway plays a crucial role in the development of liver fibrosis by activating TGFβ type Ⅱ receptor(TGFβR2), followed by the recruitment of TGFβR1 finally triggering downstream signaling pathway.AIM To find drugs targeting TGFβR2 that inhibit TGFβR1/TGFβR2 complex formation, theoretically inhibit TGFβ signaling pathway, and thereby ameliorate liver fibrosis.METHODS Food and Drug Administration-approved drugs were screened for binding affinity with TGFβR2 by virtual molecular docking. We identified 6 candidates and further explored their potential by Cell Counting Kit-8(CCK-8) cell cytotoxic experiment to validate toxicity and titrated the best cellular working concentrations. Next, we further demonstrated the detailed molecular working mechanisms using mutagenesis analysis. Finally, we used a mouse model to investigate its potential anti-liver fibrosis effect.RESULTS We identified 6 drug candidates. Among these 6 drugs, dihydroergotamine(DHE) shows great ability in reducing fibrotic gene expressions such as collagen, p-SMAD3, and α-SMA in TGFβ induced cellular model of liver fibrosis in LX-2 cells. Furthermore, we demonstrated that DHE binds to TGFβR2. Moreover, mutation of Leu27, Phe30, Thr51, Ser52, Ile53, and Glu55 of TGFβR2 disrupted the binding of TGFβR2 with DHE. In addition, DHE significantly improved liver fibrosis, as evidenced by Masson’s trichrome staining of liver sections. This is further supported by the width and the velocity of the portal vein, and serum markers of liver function. In line with those observations, DHE also decreased macrophages infiltration and extracellular matrix deposition in the liver.CONCLUSION DHE alleviates liver fibrosis by binding to TGFβR2 thereby suppressing TGFβ signaling pathway. We show here that as far as drug repurposing, DHE has great potential to treat liver fibrosis.展开更多
AIMTo evaluate whether protein tyrosine phosphatase 1B (PTP1B) contributed to initiate human retinal pigment epithelium cells (A)-19 migration and investigate the signaling pathways involved in this process.METHODSARP...AIMTo evaluate whether protein tyrosine phosphatase 1B (PTP1B) contributed to initiate human retinal pigment epithelium cells (A)-19 migration and investigate the signaling pathways involved in this process.METHODSARPE-19 cells were cultured and treated with the siRNA-PTP1B. Expression of PTP1B was confirmed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). AG1478 [a selective inhibitor of epidermal growth factor receptor (EGFR)] and PD98059 (a specific inhibitor of the activation of mitogen-activated protein kinase) were used to help to determine the PTP1B signaling mechanism. Western blot analysis verified expression of EGFR and extracellular signal-regulated kinase (ERK) in ARPE-19 cells. The effect of siRNA-PTP1B on cell differentiation was confirmed by immunostaining for α-smooth muscle actin (α-SMA) and qRT-PCR. Cell migration ability was analyzed by transwell chamber assay.RESULTSThe mRNA levels of PTP1B were reduced by siRNA-PTP1B as determined by qRT-PCR assay. SiRNA-PTP1B activated EGFR and ERK phosphorylation. α-SMA staining and qRT-PCR assay demonstrated that siRNA-PTP1B induced retinal pigment epithelium (RPE) cells to differentiate toward better contractility and motility. Transwell chamber assay proved that PTP1B inhibition improved migration activity of RPE cells. Treatment with AG1478 and PD98059 abolished siRNA-PTP1B-induced activation of EGFR and ERK, α-SMA expression and cell migration.CONCLUSIONPTP1B inhibition promoted myofibroblast differentiation and migration of ARPE-19 cells, and EGFR/ERK signaling pathway played important role in migration process.展开更多
Background:To investigate the role of fibroblast growth factor 2(FGF2)in chemotherapy resistance of colon cancer.Methods:An HCT116/5-fluorouracil(5-FU)-resistant cell line was established,and FGF2 levels were detected...Background:To investigate the role of fibroblast growth factor 2(FGF2)in chemotherapy resistance of colon cancer.Methods:An HCT116/5-fluorouracil(5-FU)-resistant cell line was established,and FGF2 levels were detected in a sensitive cell group(HCT116)and a resistant cell group(HCT1116-R)using different methods.Fibroblast growth factor 2 levels in the medium were determined by enzyme-linked immunoassay.The protein expressions of FGF2,fibroblast growth factor receptor 1(FGFR1),and phospho-FGFR1 were assessed by Western blotting,and FGF2 mRNA levels were detected by quantitative real-time polymerase chain reaction.Fibroblast growth factor 2 recombinant protein was added to sensitive cells,and FGFR inhibitor AZD4547 was added to resistant cells,and the cell survival rate was determined using the cell counting kit-8 method and the protein expressions of PI3K(phosphatidylinositol 3 kinase),p-PI3K(phospho-PI3K),Akt(protein kinase B),p-Akt(phospho-Akt),mammalian target of rapamycin(mTOR),p-mTOR(phospho-mTOR),Bad(Bcl-xL/Bcl-2-associated death promoter),NF-κB(nuclear factorκB),GSK-3(glycogen synthase kinase-3),FKHR(forkhead box protein O1),and PTEN(phosphatase and tensin homolog deleted on chromosome ten)were detected by Western blotting.Results:Fibroblast growth factor 2 protein and mRNA expression levels in the HCT116-R group were significantly higher than those in the HCT116 group.Fibroblast growth factor 2 increased the survival rate of HCT116 cells;improved tolerance to 5-FU;upregulated p-PI3K,p-Akt,and p-mTOR;and downregulated Bad.The FGFR inhibitor AZD4547 decreased cell survival rate and tolerance to 5-FU;downregulated p-PI3K,p-Akt,and p-mTOR expression;and upregulated Bad.Conclusions:Fibroblast growth factor 2 promotes chemotherapy tolerance in colon cancer cells by activating the Akt/mTOR and Akt/Bad signaling pathways downstream of PI3K.展开更多
基金Supported by Deutsche Forschungsgemeinschaft (DFG),Deutsche Krebshilfe and Sonnenfeld-Stiftung Berlin
文摘AIM: To examine the underlying mechanisms of erlotinib-induced growth inhibition in hepatocellular carcinoma (HCC). METHODS: Erlotinib-induced alterations in gene expression were evaluated using cDNA array technology; changes in protein expression and/or protein activation due to erlotinib treatment as well as IGF-1-induced EGFR transactivation were investigated using Western blotting. RESULTS: Erlotinib treatment inhibited the mitogen activated protein (MAP)-kinase pathway and signal transducer of activation and transcription (STAT)- mediated signaling which led to an altered expression of apoptosis and cell cycle regulating genes as demonstrated by cDNA array technology. Overexpression of proapoptotic factors like caspases and gadds associated with a down-regulation of antiapoptotic factors like Bcl-2, Bcl-XL or jun D accounted for erlotinib's potency to induce apoptosis. Downregulation of cell cycle regulators promoting the G1/S-transition and overexpression of cyclin-dependent kinase inhibitors and gadds contributed to the induction of a G1/G0-arrest in response to erlotinib. Furthermore, we displayed the transactivation of EGFR-mediated signaling by the IGF-1-receptor and showed erlotinib's inhibitory effects on the receptor-receptor cross talk. CONCLUSION: Our study sheds light on the understanding of the mechanisms of action of EGFR-TK- inhibition in HCC-cells and thus might facilitate the design of combination therapies that act additively or synergistically. Moreover, our data on the pathways responding to erlotinib treatment could be helpful in predicting the responsiveness of tumors to EGFR-TKIs in the future.
文摘(-)-Epigallocatechin gallate (EGCG), a major polyphenolic constituent of green tea, can inhibit activity of specific receptor tyrosine kinases (RTKs) and related downstream signal transduction pathways, resulting in the control of unwanted cell proliferation. The epidermal growth factor receptor (EGFR) signaling pathway is one of the most important pathways that regulates growth, survival,proliferation and differentiation in mammalian cells. This review addresses the effects of EGCG on some protein factors involved in the EGFR signaling pathway in a direct or indirect manner. Based on our understanding of the interaction between EGCG and these factors, and based on their structures, EGCG could be used as a lead compound for designing and synthesizing novel drugs with significant biological activity.
基金Supported by the NIH grant to Band H,No.CA99163,CA87986,CA105489 and CA116552a Department of Defense grant to Band H,No.W81WH-11-1-0167+4 种基金the NIH grant to Band V,No.CA96844 and CA144027Department of Defense grant to Band V,No.W81XWH-07-1-0351 and W81XWH-11-1-0171the Nebraska Department of Health and Human Services LB-506 grant to Band H,No.2014-01the NCI Core Support Grant to the UNMC Buffett Cancer CenterBielecki TA was a predoctoral trainee under the NCI Institutional Cancer Biology Training Grant,No.CA009476
文摘Epidermal growth factor receptor(EGFR) controls a wide range of cellular processes, and aberrant EGFR signaling as a result of receptor overexpression and/or mutation occurs in many types of cancer. Tumor cells in non-small cell lung cancer(NSCLC) patients that harbor EGFR kinase domain mutations exhibit oncogene addiction to mutant EGFR, which confers high sensitivity to tyrosine kinase inhibitors(TKIs). As patients invariably develop resistance to TKIs, it is important to delineate the cell biological basis of mutant EGFR-induced cellular transformation since components of these pathways can serve as alternate therapeutic targets to preempt or overcome resistance. NSCLC-associated EGFR mutants are constitutively-active and induce ligandindependent transformation in nonmalignant cell lines. Emerging data suggest that a number of factors are critical for the mutant EGFR-dependent tumorigenicity, and bypassing the effects of TKIs on these pathways promotes drug resistance. For example, activation of downstream pathways such as Akt, Erk, STAT3 and Src is critical for mutant EGFR-mediated biological processes. It is now well-established that the potency and spatiotemporal features of cellular signaling by receptor tyrosine kinases such as EGFR, as well as the specific pathways activated, is determined by the nature of endocytic traffic pathways through which the active receptors traverse. Recent evidence indicates that NSCLCassociated mutant EGFRs exhibit altered endocytic trafficking and they exhibit reduced Cbl ubiquitin ligasemediated lysosomal downregulation. More recent work has shown that mutant EGFRs undergo ligand-independent traffic into the endocytic recycling compartment, a behavior that plays a key role in Src pathway activation and oncogenesis. These studies are beginning to delineate the close nexus between signaling and endocytic traffic of EGFR mutants as a key driver of oncogenicprocesses. Therefore, in this review, we will discuss the links between mutant EGFR signaling and endocytic properties, and introduce potential mechanisms by which altered endocytic properties of mutant EGFRs may alter signaling and vice versa as well as their implications for NSCLC therapy.
基金supported by the National Natural Science Foundation of China(Nos.30660180,30660164 and 30660177)the Hainan Provincial Natural Science Foundation,China(No.30523)
文摘Objective:To explore the effect of hepatocyte growth factor signaling pathway activation on Plasmodium berghei infection.Methods:In this study,hepatocyte growth factor was detected by ELISA and Western blotting assay.Hepatocyte injury was detected by FITC-dextran absorption assay,and hepatocyte growth factor expression was shown to be expressed in the same injury cells by immunofluorescence against hepatocyte growth factor.In addition,Activation of hepatocyte growth factor and its receptor signaling pathway was detected with immunoprecipitation and detection of phosphorylation status.Results:It was found that injury of hepatocytes by sporozoite migration induced the secretion of hepatocyte growth factor and it was hepatocyte growth factor that rendered hepatocytes susceptible to Plasmodium sporozoite infection.In addition,hepatocyte infections depended on activation of the hepatocyte growth factor and its receptor signaling pathway.Conclusions:Our results indicate that hepatocyte growth factor and its receptor may possibly be potential targets for new approaches to malaria treatment.
基金General project of national natural science foundation of China(No.8177150469)Youth project of national natural science foundation of China(No.81804095)Project of Shanghai collaborative innovation center of health service in traditional Chinese medicine(No.ZYJKFW201701002)。
文摘Objective:persistent hyperinflammation is an important reason for the development of diabetic foot ulcer.Notch signaling is an important signaling pathway involved in the inflammatory response and cell proliferation in diabetic foot ulcer rats.This paper aims to explore the effect of Notch signaling on inflammatory factors,chemokines and growth factors through the intervention of Notch signaling in diabetic foot ulcer rats.Methods:the experimental model was made by using high-fat feed combined with streptozotocin(STZ)to cause diabetes,and the experimental model of diabetic foot ulcer was established by constant temperature and constant pressure scald apparatus.The normal ulcer model was used as a control.The intervention controls of the experimental model included normal saline,western medicine growth factor,Notch agonist Jagged1,Notch signaling inhibitor ly-411575,and the intervention of traditional Chinese medicine Zizhu ointment for 7 days.Serum il-1,il-6,TNF-radiation,and il-17 were detected by ELISA.Real-time PCR was used to detect the inflammatory factors,chemokines,and growth factors associated with Notch signaling in wound tissues:tnf-uum,il-1,il-6,il-17,interleukin-8,ip-10,McP-1,TGF-uum,TGF-livelihood.Results:serum levels of il-1,il-6,TNF-radiation and il-17 in diabetic foot ulcer rats were significantly higher than that in normal ulcer rats.The contents of il-1,il-6,TNF-radiation and il-17a in ly-411575 group and Zizhu ointment group were significantly reduced.Real-time PCR results of wound tissue showed that the levels of inflammatory cytokines il-1,il-6,TNF-radiation,il-17 and chemokines ip-10,il-8 and McP-1 in the wound tissue of diabetic foot ulcer rat model were significantly higher than that of normal ulcer model,and the levels of growth factor TGF-exposure were lower than that of normal ulcer model.LY-411575 significantly reduced il-1,il-6,TNF-maxima,il-17,and the chemokines ip-10,il-8,and McP-1 in diabetic foot ulcer rats,and reduced the expression of TGF-,TGF-earth.Jagged1 can increase the expression of TGF--,TGF---,suggesting that inhibition of the Notch signaling pathway can reduce the expression of the inflammatory factors il-1,il-6,TNF--,il-17a,il-8,and the growth factors TGF--,TGF---.Zizhu ointment can reduce the levels of il-1,il-6,TNF-benand,il-17,and the chemokines ip-10,il-8,and McP-1 on the wound surface of diabetic foot rats,and improve the expression of TGF-benand TGF-SUNS.Ly-411575 inhibited the expression of TGF-bento and TGF-promoting of Zizhu ointment.Conclusion:the expression of inflammatory cytokines and chemokines was higher and the expression of growth factors was lower in diabetic foot ulcer rats than in normal ulcer rats.Inhibition of Notch signaling pathway can reduce the expression of inflammatory factors,chemokines and growth factors in experimental model rats,and Notch signaling pathway can promote inflammation and cell proliferation.Zizhu ointment can reduce the levels of inflammatory cytokines and chemokines in diabetic foot ulcer rats,improve the expression of growth factors,and reduce wound inflammation,which may be related to the inhibition of Nocth signal expression.
文摘Epidermal growth factor receptor(EGFR)signaling has become an importanttarget for drug development becauseEGFR signaling enhances tumor cell proliferation,migration,and invasion and inhibits apoptosis.However,theresults of clinical trials using EGFR inhibitors in patients with solid tumors have been disappointing.Here,wereport a protective effect of the EGFR inhibitors AG1478 and PD153035 against cell death induced by acute hy-poxia,which contrasts with their proapoptotic effects under normoxia.Under hypoxic conditions,both agents re-
基金Supported by National Natural Science Foundation of China,No. 81502556Yunnan Digestive Endoscopy Clinical Medical Center Foundation for Health Commission of Yunnan Province,No. 2X2019-01-02
文摘BACKGROUND Colorectal cancer(CRC)is an extremely malignant tumor with a high mortality rate.Little is known about the mechanism by which forkhead Box q1(FOXQ1)causes CRC invasion and metastasis through the epidermal growth factor receptor(EGFR)pathway.AIM To illuminate the mechanism by which FOXQ1 promotes the invasion and metastasis of CRC by activating the heparin binding epidermal growth factor(HB-EGF)/EGFR pathway.METHODS We investigated the differential expression and prognosis of FOXQ1 and HB-EGF in CRC using the Gene Expression Profiling Interactive Analysis(GEPIA)website(http://gepia.cancer-pku.cn/index.html).Quantitative real-time polymerase chain reaction(qRT-PCR)and Western blotting were used to detect the expression of FOXQ1 and HB-EGF in cell lines and tissues,and we constructed a stable lowexpressing FOXQ1 cell line and verified it with the above method.The expression changes of membrane-bound HB-EGF(proHB-EGF)and soluble HB-EGF(sHB-EGF)in the lowexpressing FOXQ1 cell line were detected by flow cytometry and ELISA.Western blotting was used to detect changes in the expression levels of HB-EGF and EGFR pathway-related downstream genes when exogenous recombinant human HB-EGF was added to FOXQ1 knockdown cells.Proliferation experiments,transwell migration experiments,and scratch experiments were carried out to determine the mechanism by which FOXQ1 activates the EGFR signaling pathway through HB-EGF,and then to evaluate the clinical relevance of FOXQ1 and HB-EGF.RESULTS GEPIA showed that the expression of FOXQ1 in CRC tissues was relatively high and was related to a lower overall survival rate.PCR array results showed that FOXQ1 is related to the HB-EGF and EGFR pathways.Knockdown of FOXQ1 suppressed the expression of HB-EGF,and led to a decrease in EGFR and its downstream genes AKT,RAF,KRAS expression levels.After knockdown of FOXQ1 in CRC cell lines,cell proliferation,migration and invasion were attenuated.Adding HB-EGF restored the migration and invasion ability of CRC,but not the cell proliferation ability.Kaplan–Meier survival analysis results showed that the combination of FOXQ1 and HB-EGF may serve to predict CRC survival.CONCLUSION Based on these collective data,we propose that FOXQ1 promotes the invasion and metastasis of CRC via the HB-EGF/EGFR pathway.
文摘The epidermal growth factor receptor (EGFR) is a member of the ErbB/EGFR family, including EGFR/Herl, ErbB2/Her2, ErbB-3/Her3, and ErbB-4/Her4. EGFR exerts its effects through the receptor tyrosine kinase phosphorylation and activation of important downstream signaling pathways in normal and neoplastic cells, mainly the Ras GTPase/MAP kinase (MAPK), STAT3, and phosphatidylinositide 3 kinase-AKT pathways. EGFR deregulation is common in malignant glioma, especially primary glioblastoma, and exists in three forms: gene overexpression (amplification), autocrine effects of EGFR activation, and activating receptor mutation (EGFRvlII). However, some EGFR abnormalities have also been found in low-grade gliomas, including the nuclear localization of EGFR, expression in the microfoci of anaplastic transformation, and association with neovascularization in the mesenchyma of the glioma, which suggests that some unknown EGFR-related mechanisms are possibly responsible for its central role in the initiation and progression of malignant glioma. Uncovering these mechanisms will have potential value in the development of radio- therapy, chemotherapy, and EGFR-targeted therapy for glioma.
基金Supported by KAKENHI(partiallyGrant-in-Aid for Scientific ResearchNo.23390329)
文摘Fibroblast growth factor receptors(FGFRs) regulate a variety of cellular functions, from embryogenesis to adult tissue homeostasis. FGFR signaling also plays significant roles in the proliferation, invasion, and survival of several types of tumor cells. FGFR-induced alterations, including gene amplification, chromosomal translocation, and mutations, have been shown to be associated with the tumor initiation and progression of gastric cancer, especially in diffuse-type cancers. Therefore, the FGFR signaling pathway might be one of the therapeutic targets in gastric cancer. This review aims to provide an overview of the role of FGFR signaling in tumorigenesis, tumor progression, proliferation, and chemoresistance. We also discuss the accumulating evidence that demonstrates the effectiveness of using clinical therapeutic agents to inhibit FGFR signaling for the treatment of gastric cancer.
文摘The effect of thyrosine kinase, calmodulin and voltage-dependent Ca 2+ channel on the proliferation of hepatoma cells induced by EGF was studied. Hepatoma cell line SMMC7721 was cultured in RPMI1640 serum-free medium. DNA synthesis rate of hepatoma cells was measured by 3H-TdR incorporation. 10 -9 mol/L EGF could significantly stimulate the proliferation of hepatoma cells (P<0.05), and this effect might be significantly inhibited by tyrosine kinase inhibitor (P<0.001). Calmodulin inhibitor W-7 had no effect on the basic phase of cultured hepatoma cells (P> 0.05), but it had very significantly inhibitory effect on the proliferation of hepatoma cells induced by EGF (P<0.001). Voltage-dependent Ca 2+ channel inhibitor Varapamil had no inhibition on the proliferation of hepatoma cells induced by EGF (P>0.05). It had no effect on the basic phase of cultured hepatoma cells (P>0.05). It is suggested that tyrosine kinase and Ca 2+-calmodulin-dependent pathway may play a critical role on the proliferation of heptoma cells induced by EGF, and voltage-dependent Ca 2+ channel is independent of the effect of EGF.
文摘Objective:To investigate the effects of miR-124 overexpression on inflammatory factors and epidermal growth factor in rats with gastric precancerous lesions by modulating the Wnt/β-catenin signaling pathway.Methods:Eighty SPF-grade Wistar rats were selected as the research subjects.After adaptive feeding,they were divided into 4 groups using a random number table method.The control group was fed a regular diet,while the model group,low expression group,and overexpression group of rats were treated with N-methyl-N’-nitro-N-nitrosoguanidine to establish a model of gastric cancer precancerous lesions.After successful modeling,the control group and model group rats were injected intraperitoneally with 0.9%sodium chloride solution,the low-expression group rats were injected intraperitoneally with miR-124-5p inhibitor,and the over-expression group rats were injected intraperitoneally with miR-124-5p mimic.After 8 weeks of continuous injection,the levels of miR-124,Wnt/β-catenin signaling pathway-related proteins,inflammatory factors,and epidermal growth factor were observed and compared among the four groups of rats.Results:The differences in the relative expression of miR-124 among the four groups of rats were statistically significant(P<0.05);the differences in the expression of Wnt protein andβ-catenin protein among the four groups of rats were statistically significant(P<0.05),and the expression of Wnt protein andβ-catenin protein in the overexpression group was significantly higher than that of the control group,and significantly lower than that in the model group and the low-expression group;the levels of IL-1β,IL-6,and TNF-αof rats in the four groups of rats IL-1β,IL-6 and TNF-αlevels were statistically different(P<0.05),and the levels of IL-1β,IL-6 and TNF-αin rats in the overexpression group were higher than those in the model group and significantly lower than those in the model group and the low-expression group(P<0.05);the differences in the levels of EGF,HER1 and HER2 among the four groups of rats were statistically different(P<0.05),and the levels of EGF levels were higher than those of the control group,and EGF and HER1 were significantly lower than those of the model and low expression groups(P<0.05).Conclusion:Mi R-124 overexpression helps to reduce gastric mucosal damage and inflammatory response in rats with gastric precancerous lesions,and its mechanism of action may be linked to the inhibition of the Wnt/β-catenin signaling pathway.
基金supported by National Science Funded Project(81060017)
文摘Objective:To observe the expression changes of inflammatory markers TGF-β1,Smad3 and IL-6 in patients with atrial fibrillation(AF),and to explore the significance of TGF-β1 signaling pathway in the structural remodeling of AF.Methods:The expression of TGF-β1,Smad3 and IL-6 in 50 cases with AF and 30 normal cases were detected by RT-PCR and ELISA.Results:The TGF-β1,Smad3 and IL-6 mRNA and protein expression levels in patients with AF were significantly higher than that in the control group(P<0.05),but there was no significantly different between the paroxysmal AF group and the persistent AF group(P>0.05).The TGF-β1mRNA expression in the≥50 years subgroup was significantly higher than that in the<50years subgroups,and it was higher in the NYHAⅢsubgroup than in theⅠ/Ⅱgrade subgroup.It was also higher in the left ventricular ejection fraction(LVEF)<50%subgroup than in LVEF≥50%group,and it was significantly higher in the AF time≥36 months subgroup than that in<36months subgroup(P<0.05).The Smad3 and IL-6 expressions in the in the LVEF<50%subgroup were both high that than that in LVEF≥50%group,and higher in the AF time≥36 months subgroup than that in<36 months subgroup(P<0.05).There were a positive correlation between TGF-β1,Smad3 and IL-6(r=0.687,r=0.547).There were also a positive correlation between Smad3 and IL-6 mRNA(r=0.823).Conclusions:AF is associated with inflammation,and the inflammation is also involved in the fibrillation and sustain of AF.The TGF-β1 signal pathway may be involved in the process of atrial structural remodeling in patients with AF,and iss related with the occurrence and maintenance of AF.
基金supported by grants from National Natural Science Foundation of China(81670559)Key Research and Development Project of Shanxi Province(201603D421023)+2 种基金Youth Fund of Shanxi Medical University(02201514)Graduate Student Education Innovation Project of Shanxi(2016BY077)Youth Fund of Ap-plied Basic Research Program of Shanxi(201701D221175)
文摘Background: Previous research suggested that insulin-like growth factor binding protein related protein 1(IGFBPrP1), as a novel mediator, contributes to hepatic fibrogenesis. Matrix metalloproteinases(MMP) and tissue inhibitors of metalloproteinases(TIMP) play an essential role in hepatic fibrogenesis by regulating homeostasis and remodeling of the extracellular matrix(ECM). However, the interaction between IGFBPrP1 and MMP/TIMP is not clear. The present study was to knockdown IGFBPrP1 to investigate the correlation between IGFBPrP1 and MMP/TIMP in hepatic fibrosis. Methods: Hepatic fibrosis was induced by thioacetamide(TAA) in mice. Knockdown of IGFBPrP1 expression by ultrasound-targeted microbubble destruction-mediated CMB-shRNA-IGFBPrP1 delivery, or inhibition of the Hedgehog(Hh) pathway by cyclopamine treatment, was performed in TAA-induced liver fibrosis mice. Hepatic fibrosis was determined by hematoxylin and eosin and Sirius red staining. Hepatic expression of IGFBPrP1, α-smooth muscle actin( α-SMA), transforming growth factor β 1(TGF β1), collagen I, MMPs/TIMPs, Sonic Hedgehog(Shh), and glioblastoma family transcription factors(Gli1) were investigated by immunohistochemical staining and Western blotting analysis. Results: We found that hepatic expression of IGFBPrP1, TGF β1, α-SMA, and collagen I were increased longitudinally in mice with TAA-induced hepatic fibrosis, concomitant with MMP2/TIMP2 and MMP9/TIMP1 imbalance and Hh pathway activation. Knockdown of IGFBPrP1 expression, or inhibition of the Hh pathway, reduced the hepatic expression of IGFBPrP1, TGF β1, α-SMA, and collagen I and re-established MMP2/TIMP2 and MMP9/TIMP1 balance. Conclusions: Our findings suggest that IGFBPrP1 knockdown attenuates liver fibrosis by re-establishing MMP2/TIMP2 and MMP9/TIMP1 balance, concomitant with the inhibition of hepatic stellate cell activation, down-regulation of TGF β1 expression, and degradation of the ECM. Furthermore, the Hh pathway mediates IGFBPrP1 knockdown-induced attenuation of hepatic fibrosis through the regulation of MMPs/TIMPs balance.
基金Supported by UK National Institute of Health Research/Cancer Research Network (UK NIHR/UKCRN) and Research and Development Department of Wrightington Wigan and Leigh NHS Foundation Trust (to Ang YS)R Keld WrightingtonWigan and Leigh NHS Foundation Trust Cancer Therapy Fund(to Keld RR,in part)
文摘Cancer treatments are rapidly changing.Curative treatment for oesophageal adenocarcinoma currently involves surgery and cytotoxic chemotherapy or chemoradiotherapy.Outcomes for both regimes are generally poor as a result of tumor recurrence.We have reviewed the key signalling pathways associated with oesophageal adenocarcinomas and discussed the recent trials of novel agents that attempt to target these pathways.There are many trials underway with the aim of improving survival in oesophageal cancer.Currently,phase 2 and 3 trials are focused on MAP kinase inhibition,either through inhibition of growth factor receptors or signal transducer proteins.In order to avoid tumor resistance,it appears to be clear that targeted therapy will be needed to combat the multiple signalling pathways that are in operation in oesophageal adenocarcinomas.This may be achievable in the future with the advent of gene signatures and a combinatorial approach.
文摘AIM: To investigate the effect of microR NA on insulinlike growth factor binding protein-3(IGFBP-3) and hence on insulin-like growth factor-Ⅱ(IGF-Ⅱ) bioavailability in hepatocellular carcinoma(HCC).METHODS: Bioinformatic analysis was performed using microrna.org, DIANA lab and Segal lab softwares. Total RNA was extracted from 23 HCC and 10 healthy liver tissues using mir Vana mi RNA Isolation Kit. microR NA-17-5p(miR-17-5p) expression was mimicked and antagonized in Hu H-7 cell lines using Hi Per Fect Transfection Reagent, then total RNA was extracted using Biozol reagent then reverse transcribed into cD NA followed by quantification of mi R-17-5p and IGFBP-3 expression using Taq Man real-time quantitative PCR. Luciferase reporter assay was performed to validate the binding of miR-17-5p to the 3'UTR of IGFBP-3. Free IGF-Ⅱ protein was measured in transfected Hu H-7 cells using IGF-Ⅱ ELISA kit. RESULTS: Bioinformatic analysis revealed IGFBP-3 as a potential target for miR-17-5p. Screening of miR-17-5p and IGFBP-3 revealed a moderate negative correlation in HCC patients, where mi R-17-5p was extensively underexpressed in HCC tissues(P = 0.0012), while IGFBP-3 showed significant upregulation in the same set of patients(P = 0.0041) compared to healthy donors. Forcing mi R-17-5p expression in Hu H-7 cell lines showed a significant downregulation of IGFBP-3 mR NA expression(P = 0.0267) and a significant increase in free IGF-Ⅱ protein(P = 0.0339) compared to mock untransfected cells using unpaired t-test. Luciferase assay validated IGFBP-3 as a direct target of mi R-17-5p; luciferase activity was inhibited by 27.5% in cells co-transfected with miR-17-5p mimics and the construct harboring the wild-type binding region 2 of IGFBP-3 compared to cells transfected with this construct alone(P = 0.0474).CONCLUSION: These data suggest that regulating IGF-Ⅱ bioavailability and hence HCC progression can be achieved through targeting IGFBP-3 via manipulating the expression of miR NAs.
文摘Objective To determine whether transforming growth factor betal (TGF-β1)/Smad signaling pathway mediates p53-dependent apoptosis in hepatoma cell lines.Methods Three human hepatic carcinoma cell lines, HepG2, Huh-7, and Hep3B, were used in this study.TGF-β1-induced apoptosis in hepatic carcinoma cell lines was analyzed using TUNEL assay.For identifying the mechanism of apoptosis induced by TGF-β1, cell lines were transfected with a TGF-β1-inducible luciferase reportor plasmid containing Smad4 binding elements.After transfection, cells were treated with TGF-β1, then assayed for luciferase activity.Results The apoptosis rate of HepG2 cell lines (48.51%± 8.21%) was significantly higher than control ( 12.72%±2.18%, P<0.05).But TGF-β1 was not able to induce apoptosis of Huh-7 and Hep3B cell lines.The relative luciferase activity of TGF-β1-treated HepG2 cell lines (4.38) was significantly higher than control (1.00, P< 0.05).But the relative luciferase activity of TGF-β1-treated Huh-7 and Hep3B cell lines less increased compared with control.Conclusions HepG2 cells seem to be highly susceptible to TGF-β1-induced apoptosis compared with Hep3B and Huh-7 cell lines.Smad4 is a central mediator of TGF-β1 signaling transdution pathway.TGF-β1/Smad signaling pathway might mediate p53-dependent apoptosis in hepatoma cell lines.
文摘The present study characterized the nerve growth factor (NGF)-mediated regulation of tau protein expression and transcription in IMR32 human neuroblastoma cells. Treatment of IMR32 cells with 50 ng/mL NGF resulted in increased levels of specific tau protein isoforms. A 550 bp fragment of the tau promoter was cloned and treatment of transfected IMR32 and PC12 cells with NGF also resulted in increased promoter activation, suggesting that the NGF-mediated increase in tau isoforms is regulated, at least in part, at the level of transcription. Pretreatment with the MAP kinase inhibitor U0126 or the PKC inhibitor bisindolylmaleimide 1 (BIS-1) attenuated the NGF-mediated increase in tau transcription, indicating that the NGF-mediated activation of the MAP kinase and PKC signaling pathways modulate tau transcription. Pre-treatment of cells with the Akt inhibitor, LY294002 or with NOS inhibitors Nω-nitro-L-arginine methylester (L-NAME) or s-methylisothiourea (S-MIU) had no effect on the NGF-mediated increase in tau promoter activation, suggesting that NO and the NGF-Akt signaling pathway do not modulate tau transcription. Taken together, these data demonstrate that NGF increases the levels of multiple human tau isoforms in IMR32 cells which may result, at least in part, from NGF-mediated PKC and MAP kinase-induced tau transcription.
基金Supported by the Special Research Project for Capital Health Development,No.2022-2-2174the Beijing Municipal Science and Technology Commission,No.Z191100007619037.
文摘BACKGROUND The transforming growth factor β(TGFβ) signaling pathway plays a crucial role in the development of liver fibrosis by activating TGFβ type Ⅱ receptor(TGFβR2), followed by the recruitment of TGFβR1 finally triggering downstream signaling pathway.AIM To find drugs targeting TGFβR2 that inhibit TGFβR1/TGFβR2 complex formation, theoretically inhibit TGFβ signaling pathway, and thereby ameliorate liver fibrosis.METHODS Food and Drug Administration-approved drugs were screened for binding affinity with TGFβR2 by virtual molecular docking. We identified 6 candidates and further explored their potential by Cell Counting Kit-8(CCK-8) cell cytotoxic experiment to validate toxicity and titrated the best cellular working concentrations. Next, we further demonstrated the detailed molecular working mechanisms using mutagenesis analysis. Finally, we used a mouse model to investigate its potential anti-liver fibrosis effect.RESULTS We identified 6 drug candidates. Among these 6 drugs, dihydroergotamine(DHE) shows great ability in reducing fibrotic gene expressions such as collagen, p-SMAD3, and α-SMA in TGFβ induced cellular model of liver fibrosis in LX-2 cells. Furthermore, we demonstrated that DHE binds to TGFβR2. Moreover, mutation of Leu27, Phe30, Thr51, Ser52, Ile53, and Glu55 of TGFβR2 disrupted the binding of TGFβR2 with DHE. In addition, DHE significantly improved liver fibrosis, as evidenced by Masson’s trichrome staining of liver sections. This is further supported by the width and the velocity of the portal vein, and serum markers of liver function. In line with those observations, DHE also decreased macrophages infiltration and extracellular matrix deposition in the liver.CONCLUSION DHE alleviates liver fibrosis by binding to TGFβR2 thereby suppressing TGFβ signaling pathway. We show here that as far as drug repurposing, DHE has great potential to treat liver fibrosis.
基金Supported by Shandong Provincial Natural Science Foundation,China(No.ZR2012HQ004)the Research Fund for Fundamental Research Project of Qingdao(No.13-1-4-180-jch)+1 种基金the Scientific Research Fund of Huangdao District of Qingdao City(No.2014-1-74)the Young People Scientific Research Fund of Affiliated Hospital,Qingdao University(No.QDFY134)
文摘AIMTo evaluate whether protein tyrosine phosphatase 1B (PTP1B) contributed to initiate human retinal pigment epithelium cells (A)-19 migration and investigate the signaling pathways involved in this process.METHODSARPE-19 cells were cultured and treated with the siRNA-PTP1B. Expression of PTP1B was confirmed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). AG1478 [a selective inhibitor of epidermal growth factor receptor (EGFR)] and PD98059 (a specific inhibitor of the activation of mitogen-activated protein kinase) were used to help to determine the PTP1B signaling mechanism. Western blot analysis verified expression of EGFR and extracellular signal-regulated kinase (ERK) in ARPE-19 cells. The effect of siRNA-PTP1B on cell differentiation was confirmed by immunostaining for α-smooth muscle actin (α-SMA) and qRT-PCR. Cell migration ability was analyzed by transwell chamber assay.RESULTSThe mRNA levels of PTP1B were reduced by siRNA-PTP1B as determined by qRT-PCR assay. SiRNA-PTP1B activated EGFR and ERK phosphorylation. α-SMA staining and qRT-PCR assay demonstrated that siRNA-PTP1B induced retinal pigment epithelium (RPE) cells to differentiate toward better contractility and motility. Transwell chamber assay proved that PTP1B inhibition improved migration activity of RPE cells. Treatment with AG1478 and PD98059 abolished siRNA-PTP1B-induced activation of EGFR and ERK, α-SMA expression and cell migration.CONCLUSIONPTP1B inhibition promoted myofibroblast differentiation and migration of ARPE-19 cells, and EGFR/ERK signaling pathway played important role in migration process.
基金supported by the National Natural Science Foundation of China (no. 81904109)the Natural Science Project of Hunan Provincial Department of Science and Technology (no.2023JJ30361, no. 2019JJ50344).
文摘Background:To investigate the role of fibroblast growth factor 2(FGF2)in chemotherapy resistance of colon cancer.Methods:An HCT116/5-fluorouracil(5-FU)-resistant cell line was established,and FGF2 levels were detected in a sensitive cell group(HCT116)and a resistant cell group(HCT1116-R)using different methods.Fibroblast growth factor 2 levels in the medium were determined by enzyme-linked immunoassay.The protein expressions of FGF2,fibroblast growth factor receptor 1(FGFR1),and phospho-FGFR1 were assessed by Western blotting,and FGF2 mRNA levels were detected by quantitative real-time polymerase chain reaction.Fibroblast growth factor 2 recombinant protein was added to sensitive cells,and FGFR inhibitor AZD4547 was added to resistant cells,and the cell survival rate was determined using the cell counting kit-8 method and the protein expressions of PI3K(phosphatidylinositol 3 kinase),p-PI3K(phospho-PI3K),Akt(protein kinase B),p-Akt(phospho-Akt),mammalian target of rapamycin(mTOR),p-mTOR(phospho-mTOR),Bad(Bcl-xL/Bcl-2-associated death promoter),NF-κB(nuclear factorκB),GSK-3(glycogen synthase kinase-3),FKHR(forkhead box protein O1),and PTEN(phosphatase and tensin homolog deleted on chromosome ten)were detected by Western blotting.Results:Fibroblast growth factor 2 protein and mRNA expression levels in the HCT116-R group were significantly higher than those in the HCT116 group.Fibroblast growth factor 2 increased the survival rate of HCT116 cells;improved tolerance to 5-FU;upregulated p-PI3K,p-Akt,and p-mTOR;and downregulated Bad.The FGFR inhibitor AZD4547 decreased cell survival rate and tolerance to 5-FU;downregulated p-PI3K,p-Akt,and p-mTOR expression;and upregulated Bad.Conclusions:Fibroblast growth factor 2 promotes chemotherapy tolerance in colon cancer cells by activating the Akt/mTOR and Akt/Bad signaling pathways downstream of PI3K.