Objective To investigate the protective effects of hydrogen peroxide preconditioning (HPP) on the pheochromocytoma (PC12) cells treated with 1-methyl-4-phenylpyridinium (MPP^+) and to explore the potential mech...Objective To investigate the protective effects of hydrogen peroxide preconditioning (HPP) on the pheochromocytoma (PC12) cells treated with 1-methyl-4-phenylpyridinium (MPP^+) and to explore the potential mechanisms. Methods The viability and apoptosis of PC 12 cells were determinded by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and 4′,6′-diamidino-2-phenylindole (DAPI) staining, respectively. The expressions of 14-3-3 protein and phospholylated p38 mitogen-activated protein kinase (MAPK) were determined by Western blot. Enzyme-linked immunosorbent assay (ELISA) was used to measure the activity of extracellular signal-regulated protein kinase 1/2 (ERK1/2). Results The cell viability decreased and the number of apoptotic cells increased dramatically in MPP^+ group compared with that in Control group. HPP induced a significant increase in cell viability and a marked decrease in population of apoptotic cells of the MPP^+- treated PC 12 cells, accompanied with up-regulation of 14-3-3 protein and increase of ERK 1/2 and p38 MAPK activities. The 14-3-3 protein expression was positively correlated with the phosphorylation of ERK1/2. Furthermore, inhibition of the ERK1/2 with PD98059 abolished the 14-3-3 protein up-regulation in PC 12 cells induced by HPP. Conclusion HPP protects PC 12 cells against MPP+ toxicity by up-regulating 14-3-3 protein expression through the ERK1/2 and p38 MAPK signaling pathways.展开更多
Objective The present study aimed to explore the role of P2Y1 receptor in glial fibrillary acidic protein (GFAP) production and glial cell line-derived neurotrophic factor (GDNF) secretion of astrocytes under isch...Objective The present study aimed to explore the role of P2Y1 receptor in glial fibrillary acidic protein (GFAP) production and glial cell line-derived neurotrophic factor (GDNF) secretion of astrocytes under ischemic insult and the related signaling pathways. Methods Using transient right middle cerebral artery occlusion (tMCAO) and oxygen-glucose-serum deprivation for 2 h as the model of ischemic injury in vivo and in vitro, immunofluorescence, quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, enzyme linked immunosorbent assay (ELISA) were used to investigate location of P2Y1 receptor and GDNF, the expression of GFAP and GDNF, and the changes of signaling molecules. Results Blockage of P2Y1 receptor with the selective antagonist N^6-methyl-2′-deoxyadenosine 3′,5′-bisphosphate diammonium (MRS2179) reduced GFAP production and increased GDNF production in the antagonist group as compared with simple ischemic group both in vivo and in vitro. Oxygen-glucose-serum deprivation and blockage of P2Y1 receptor caused elevation of phosphorylated Akt and cAMP response element binding protein (CREB), and reduction of phosphorylated Janus kinase2 (JAK2) and signal transducer and activator of transcription3 (STAT3, Ser727). After blockage of P2Y1 receptor and deprivation of oxygen-glucose-serum, AG490 (inhibitor of JAK2) reduced phosphorylation of STAT3 (Ser727) as well as expression of GFAP; LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3-K), decreased phosphorylation of Akt and CREB; the inhibitor of mitogen-activated protein kinase kinase 1/2 (MEK 1/2) U0126, an important molecule of Ras/extracellular signal- regulated kinase (ERK) signaling pathway, decreased the phosphorylation of JAK2, STAT3 (Ser727), Akt and CREB. Conclusion These results suggest that P2Y1 receptor plays a role in the production of GFAP and GDNF in astrocytes under transient ischemic condition and the related signaling pathways may be JAK2/STAT3 and PI3-K/Akt/CREB, respectively, and that crosstalk probably exists between them.展开更多
AIM: To study the relationship between interleukin-lbeta (IL-1β) up-regulating tissue inhibitor of matrix metalloproteinase-1 (TIMMP-1) mRNA expression and phosphorylation of both c-jun N-terminal kinase (INK)...AIM: To study the relationship between interleukin-lbeta (IL-1β) up-regulating tissue inhibitor of matrix metalloproteinase-1 (TIMMP-1) mRNA expression and phosphorylation of both c-jun N-terminal kinase (INK) and p38 in rat heffatic stellate cells (HSC). METHODS: RT-PCR was performed to measure the expression of TIMMP-1 mRNA in rat HSC. Western blot was performed to measure IL-1β-induced JNK and p38 activities in rat HSC. RESULTS: TIMMP-1 mRNA expression (1.191± 0.079) was much higher after treatment with IL-1β (10 ng/mL) for 24 h than in control group (0.545±0.091) (P〈0.01). IL-1β activated INK and p38 in a time-dependent manner. After stimulation with IL-1β for 0, 5, 15, 30, 60 and 120 min, the INK activity was 0.982±0.299, 1.501±0.720, 2.133±0.882, 3.360±0.452, 2.181±0.789, and 1.385 ± 0.368, respectively. There was a significant difference in JNK activity at 15 min (P〈 0.01), 30 min (P〈 0.01) and 60 min (P〈0.01) in comparison to that at 0 min. The p38 activity was 1.061±0.310, 2.050±0.863, 2.380±0.573, 2.973±0.953, 2.421±0.793, and 1.755 ± 0.433 at the 6 time points (0, 5, 15, 30, 60 and 120 min) respectively. There was a significant difference in p38 activity at 5 min (P〈0.05), 15 min (P〈0.01), 30 min (P〈0.01) and 60 min (P〈0.01) compared to that at 0 min. TIMMP-1 mRNA expression trended to decrease in 3 groups pretreated with different concentrations of SP600125 (10 μmol/L, 1.022±0.113; 20 μmol/L, 0.869±0.070; 40 μmol/L, 0.666±0.123). Their decreases were all significant (P〈0.05, P〈0.01, P〈0.01) in comparison to control group (without SP600125 treatment, 1.163±0.107). In the other 3 groups pretreated with different concentrations of SB203580 (10 μmol/L, 1.507±0.099; 20 μmol/L, 1.698±0.107; 40 μmol/L, 1.857±0.054), the expression of TIMMP-1 mRNA increased. Their levels were higher than those in the control group (without SB203580 treatment, 1.027 ± 0.061) with a significant statistical significance (P〈 0.01). CONCLUSION: IL-1β has a direct action on hepatic fibrosis by up-regulating TIMMP-1 mRNA expression in ratessionin in rate HSC.JNK and p38 mitogen-activated protein kinases (MAPKs) are involved in IL-1β-induced TIMMP-1 gene expression, and play a distinct role in this process, indicating that p38 and .INK pathways cooperatively mediate TIMP-1 mRNA expression in rat HSC.展开更多
The p27Kip1 is a cell cycle repressor protein that regulates primarily the cell cycle transition from G1 to S phase and hence the DNA replication is in the S phase and cell division in the M phase. Expression of p27Ki...The p27Kip1 is a cell cycle repressor protein that regulates primarily the cell cycle transition from G1 to S phase and hence the DNA replication is in the S phase and cell division in the M phase. Expression of p27Kip1 protein has dual roles for both cancer prevention and promotion. For example, numerous nutritional and chemopreventive anti-cancer agents specifically increase the expression of p27Kip1 protein without directly affecting the expression of any other cell cycle regulatory proteins. On the other hand, pro-cancer agents (like glucose, insulin and other growth factors frequently seen in obesity and/or diabetes) specifically decrease the expression of p27Kip1 protein without directly affecting the expression of any other cell cycle regulatory proteins. Unlike expression of any other cell cycle regulatory proteins, expression of p27Kip1 protein is very unusual. The mRNA of p27Kip1 has a very long and unusual 5’-untranslated region (from -575 to -1 in human). It appears that the 5’-untranslated region of p27Kip1 mRNA forms two alternative secondary structures. One increases the expression of p27Kip1 protein when anti-cancer agents are added and another decrease the expression of p27K1p1 when pro-cancer agents are added. For this short concept proposal, Dr. Albert Einstein’s “visualized thought experiments (German: Gedanken experiment)” were used as a fundamental tool for understanding how either anti- or pro-cancer agents bring the primary structure of the 5’-untranslated region of p27Kip1 mRNA into two alternative secondary structures, thereby either increasing or decreasing, respectively, the translation initiation of p27Kip1 protein.展开更多
BACKGROUND Hepatitis B surface antigen(HBsAg)loss,a functional cure in patients with chronic hepatitis B(CHB)undergoing antiviral therapy,might be an ideal endpoint of antiviral treatment in clinical practice.The fact...BACKGROUND Hepatitis B surface antigen(HBsAg)loss,a functional cure in patients with chronic hepatitis B(CHB)undergoing antiviral therapy,might be an ideal endpoint of antiviral treatment in clinical practice.The factors that contribute to the functional cure remain unclear,and the predictors of functional cure are worth exploring.The concentration and kinetics of soluble programmed death-1(sPD-1)in patients with CHB may play an important role in elucidating the immune response associated with functional cure after nucleos(t)ide analogs therapy.AIM To investigate the factors associated with HBsAg loss and explore the influence of sPD-1 Levels.METHODS This study analyzed the data and samples from patients with CHB who underwent antiviral treatment in a non-interventional observational study conducted at Peking University First Hospital in Beijing(between 2007 and 2019).All patients were followed up:Serum samples were collected every 3 mo during the first year of antiviral treatment and every 6 mo thereafter.Patients with positive hepatitis B e antigen levels at baseline and with available sequential samples who achieved HBsAg loss during antiviral treatment served as the case group.This case group(n=11)was further matched to 44 positive hepatitis B e anti patients without HBsAg loss as controls.The Spearman’s rank correlation test and receiver operating characteristic curves analysis were performed.RESULTS The sPD-1 Levels were higher in patients with HBsAg loss than in those without HBsAg loss from baseline to month 96,and the differences were significant between the groups at baseline(P=0.0136),months 6(P=0.0003),12(P<0.0001),24(P=0.0007),48(P<0.0001),and 96(P=0.0142).After 6 mo of antiviral treatment,the sPD-1 levels were positively correlated with alanine transaminase(ALT)levels(r=0.5103,P=0.0017),and the sPD-1 levels showed apparent correlation with ALT(r=0.6883,P=0.0192)and HBV DNA(r=0.5601,P=0.0703)levels in patients with HBsAg loss.After 12 mo of antiviral treatment,the sPD-1 levels also showed apparent correlation with ALT(r=0.8134,P=0.0042)and HBV DNA(r=0.6832,P=0.0205)levels in patients with HBsAg loss.The sPD-1 levels were negatively correlated with HBsAg levels in all patients after 12 mo of antiviral treatment,especially at 24(r=-0.356,P=0.0497)and 48(r=-0.4783,P=0.0037)mo.After 6 mo of antiviral treatment,the AUC of sPD-1 for HBsAg loss was 0.898(P=0.000),whereas that of HBsAg was 0.617(P=0.419).The cut-off value of sPD-1 was set at 2.34 log pg/mL;the sensitivity and specificity were 100%and 66.7%,respectively.CONCLUSION The sPD-1 levels at 6 mo can predict HBsAg loss after 144 mo of antiviral treatment.展开更多
HIV-1 matrix protein (MA) is a multifunctional structural protein localized on N terminus of Gag precursor p55. MA participates in HIV-1 assembly as membranotropic part of Gag precursor as well as an individual protei...HIV-1 matrix protein (MA) is a multifunctional structural protein localized on N terminus of Gag precursor p55. MA participates in HIV-1 assembly as membranotropic part of Gag precursor as well as an individual protein spliced from Gag early in infection. MA is found in the nuclei of infected cells and in plasma membrane, the site of virus assembly, in association with viral genome RNA. MA mutated variant M4 which contains two changed amino acids in N-terminal regions is also associated with viral RNA, but it is localized in the nuclear and cytoskeleton fractions but not in the plasma membrane suggesting that the mutant is deprived of membranotropic signal and “sticks” in the nuclei an d cytoskeleton, its previous location sites. These data allow suggesting that MA involved into transmission of viral RNA is transported to plasma membrane by cytoskeleton.展开更多
The mechanism and interaction among Rb/p16, Rb/E2F1 and HDAC1 proteins in gallbladder carcinoma were investigated. By using the immunoprecipitation method, the interactions among Rb, p16, E2F1, HDAC1 proteins in gallb...The mechanism and interaction among Rb/p16, Rb/E2F1 and HDAC1 proteins in gallbladder carcinoma were investigated. By using the immunoprecipitation method, the interactions among Rb, p16, E2F1, HDAC1 proteins in gallbladder carcinoma cell line (Mz-ChA-1) were studied. It was found that there were Rb and E2F1 proteins in the precipitates with anti-HDAC1, and there were HDAC1 and E2F1 proteins in the precipitate with anti-Rb. It was concluded that there are specific interactions among Rb, HDAC1 and E2F1 proteins in gallbladder carcinoma, indicating the existence of the direct Rb/E2F1/HDAC1 signal transduction pathway. There is no direct relationship between p16 proteins with Rb, HDAC1, and E2F1 proteins.展开更多
Amyotrophic lateral sclerosis and frontotemporal lobar degeneration are multifaceted diseases with genotypic,pathological and clinical overlap.One such overlap is the presence of SQSTM1/p62 mutations.While traditional...Amyotrophic lateral sclerosis and frontotemporal lobar degeneration are multifaceted diseases with genotypic,pathological and clinical overlap.One such overlap is the presence of SQSTM1/p62 mutations.While traditionally mutations manifesting in the ubiquitin-associated domain of p62 were associated with Paget’s disease of bone,mutations affecting all functional domains of p62 have now been identified in amyotrophic lateral sclerosis and frontotemporal lobar degeneration patients.p62 is a multifunctional protein that facilitates protein degradation through autophagy and the ubiquitin-proteasome system,and also regulates cell survival via the Nrf2 antioxidant response pathway,the nuclear factor-kappa B signaling pathway and apoptosis.Dysfunction in these signaling and protein degradation pathways have been observed in amyotrophic lateral sclerosis and frontotemporal lobar degeneration,and mutations that affect the role of p62 in these pathways may contribute to disease pathogenesis.In this review we discuss the role of p62 in these pathways,the effects of p62 mutations and the effect of mutations in the p62 modulator TANK-binding kinase 1,in relation to amyotrophic lateral sclerosis-frontotemporal lobar degeneration pathogenesis.展开更多
Alterations in embryonic neural stem cells play crucial roles in the pathogenesis of amyotrophic lateral sclerosis. We hypothesized that embryonic neural stem cells from SOD1G93A individuals might be more susceptible ...Alterations in embryonic neural stem cells play crucial roles in the pathogenesis of amyotrophic lateral sclerosis. We hypothesized that embryonic neural stem cells from SOD1G93A individuals might be more susceptible to oxidative injury, resulting in a propensity for neurodegeneration at later stages. In this study, embryonic neural stem cells obtained from human superoxide dis- mutase 1 mutant (SOD1G93A) and wild-type (SOD1wv) mouse models were exposed to H202. We assayed cell viability with mitochondrial succinic dehydrogenase colorimetric reagent, and measured cell apoptosis by flow cytometry. Moreover, we evaluated the expression of the adenos- ine monophosphate-activated protein kinase (AMPK) ct-subunit, paired box 3 (Pax3) protein, and p53 in western blot analyses. Compared with SOD1wr cells, SOD1~93A embryonic neural stem cells were more likely to undergo H202-induced apoptosis. Phosphorylation of AMPKct in SOD1G93A cells was higher than that in SOD1wr cells. Pax3 expression was inversely correlated with the phosphorylation levels of AMPKct. p53 protein levels were also correlated with AMPKct phosphorylation levels. Compound C, an inhibitor of AMPKa, attenuated the effects of H20~. These results suggest that embryonic neural stem cells from SOD1C93A mice are more susceptible to apoptosis in the presence of oxidative stress compared with those from wild-type controls, and the effects are mainly mediated by Pax3 and p53 in the AMPKa pathway.展开更多
AIM: To identify kinases involved in phenotype regulation of vascular endothelial cells(VECs): Proproliferative G-protein signaling 5(RGS5)^(high)(typeⅠ) vs anti-proliferative RGS5^(low)(typeⅡ) VECs.METHODS: Proteom...AIM: To identify kinases involved in phenotype regulation of vascular endothelial cells(VECs): Proproliferative G-protein signaling 5(RGS5)^(high)(typeⅠ) vs anti-proliferative RGS5^(low)(typeⅡ) VECs.METHODS: Proteomic kinase assays were performed to identify the crucial kinase involved in the phenotype regulation of human VECs using typeⅠ VECs, which promotes the proliferation of human vascular smooth muscle cells(VSMCs), and typeⅡ VECs, which suppress the proliferation of human VSMCs. The assays were performed using multiple pairs of typeⅠ and typeⅡ VECs to obtain the least number of candidates. The involvement of the candidate kinases was verified by evaluating the effects of their specific inhibitors on the phenotype regulation of human VECs as well as the expression levels of regulator of RGS5, which is the causative gene for the "typeⅡ to typeⅠ" phenotype conversion of human VECs. RESULTS: p38α mitogen-activated protein kinase(p38α MAPK) was the only kinase that showed distinctive activities between typeⅠ and typeⅡ VECs: p38α MAPK activities were low and high in type-Ⅰand typeⅡ VECs, respectively. We found that an enforced expression of RGS5 indeed lowered p38α MAPK activitiesin typeⅡ VECs. Furthermore, treatments with a p38α MAPK inhibitor nullified the anti-proliferative potential in typeⅡ VECs. Interestingly, MAPK inhibitor treatments enhanced the induction of RGS5 gene. Thus, there is a vicious cycle between "RGS5 induction" and "p38α MAPK inhibition", which can explain the unidirectional process in the stress-induced "typeⅡ to typeⅠ" conversions of human VECs. To understand the upstream signaling of RGS5, which is known as an inhibitory molecule against the G protein-coupled receptor(GPCR)-mediated signaling, we examined the effects of RGS5 overexpression on the signaling events from sphingosine-1-phosphate(S1P) to N-cadherin, because S1 P receptors belong to the GPCR family gene and N-cadherin, one of their downstream effectors, is reportedly involved in the regulation of VEC-VSMC interactions. We found that RGS5 specifically bound with S1P1. Moreover, N-cadherin localization at intercellular junctions in typeⅡ VECs was abolished by "RGS5 overexpression" and "p38α MAPK inhibition".CONCLUSION: p38α MAPK plays crucial roles in "type-Ⅰ vs type-Ⅱ" phenotype regulations of human VECs at the downstream of RGS5.展开更多
AIM: To investigate the mechanism of calcyclin binding protein/Siah-1 interacting protein(Cacy BP/SIP) nuclear translocation in promoting the proliferation of gastric cancer(GC) cells. METHODS: The effect of Cacy BP/S...AIM: To investigate the mechanism of calcyclin binding protein/Siah-1 interacting protein(Cacy BP/SIP) nuclear translocation in promoting the proliferation of gastric cancer(GC) cells. METHODS: The effect of Cacy BP/SIP nuclear translocation on cell cycle was investigated by cell cycle analysis. Western blot analysis was used to assess the change in expression of cell cycle regulatory proteins and proteasome-mediated degradation of p27Kip1. Coimmunoprecipitation(co-IP) analysis was performed to examine the binding of Cacy BP/SIP with Skp1. A Cacy BP/SIP truncation mutant which lacked the Skp1 binding site was constructed and fused to a fluorescent protein. Subsequently, the effect on Skp1 binding with the fusion protein was examined by co-IP, while localization of fluorescent fusion protein observed by confocal laser microscopy, and change in p27Kip1protein expression assessed by Western blot analysis.RESULTS: Cacy BP/SIP nuclear translocation induced by gastrin promoted progression of GC cells from G1 phase. However, while Cacy BP/SIP nuclear translocation was inhibited using si RNA to suppress Cacy BP/SIP expression, cell cycle was clearly inhibited. Cacy BP/SIP nuclear translocation significantly decreased the level of cell cycle inhibitor p27Kip1, increased Cyclin E protein expression whereas the levels of Skp1, Skp2, and CDK2 were not affected. Upon inhibition of Cacy BP/SIP nuclear translocation, there were no changes in protein levels of p27Kip1 and Cyclin E, while p27Kip1 decrease could be prevented by the proteasome inhibitor MG132. Moreover, Cacy BP/SIP was found to bind to Skp1 by immunoprecipitation, an event that was abolished by mutant Cacy BP/SIP, which also failed to stimulate p27Kip1 degradation, even though the mutant could still translocate into the nucleus.CONCLUSION: Cacy BP/SIP nuclear translocation contributes to the proliferation of GC cells, and Cacy BP/SIP exerts this effect, at least in part, by stimulating ubiquitin-mediated degradation of p27Kip1.展开更多
Objective: Impaired signal transduction is associated with tumorigenesis and progression of various kinds of human cancers. Transforming growth factor (TGF)-beta/Smad and ras-mitogen activated protein kinase (MAPK...Objective: Impaired signal transduction is associated with tumorigenesis and progression of various kinds of human cancers. Transforming growth factor (TGF)-beta/Smad and ras-mitogen activated protein kinase (MAPK) are two major signal transduction pathways for adjusting cell proliferation and differentiation. Little is known about TGF-beta/Smad4 in non-small cell lung cancer (NSCLC). Hereby, we investigated the expression of Smad4 in NSCLC, its correlation with MAPK proteins (including p38, ERK1 and JNK1 proteins) and their clinical significance in NSCLC. Methods: The expressions of Smad4, p38, ERK1 and JNK1 were detected at protein level with Western blotting and immunohistochemistry, at transcription level with RT-PCR. Statistical analysis was performed for the comparisons of expressions of Smad4, p38, ERK1 and JNK1, and their correlation with various clinicopathological parameters and the prognosis of NSCLC. Results: The levels of protein and mRNA expression of Smad4 in lung cancer tissues were significantly lower than in normal tissues (P〈0.05). All these four proteins were associated with TNM staging. There was a strongly negative correlation between p38 and Smad4. Expressions of Smad4, p38 and JNK1, as well as tumor differentiation and staging were significantly correlated with the prognosis of NSCLC by univariate analysis. By multivariate analysis, only Smad4, p38, tumor differentiation and staging were correlated with the prognosis. Taken together, the negative expression of p38 and positive expression of Smad4 were associated with a better prognosis of NSCLC. Conclusion: Smad4 could be of vital importance for the initiation and development of NSCLC. The expression of Smad4 might be inhibited by p38, supporting a cross-talk between main proteins of TGF-beta/Smad and ras-MAPK signal transduction pathways. Smad4 and p38 could be possible prognostic factors for NSCLC.展开更多
Objective To investigate the significance of overexpresson of cyclin D1 and P53 protein in cervical squamous cell carcinomas.Methods Fifty cases of invasive cervical squamous cell carcinomas and 10 cases of normal c...Objective To investigate the significance of overexpresson of cyclin D1 and P53 protein in cervical squamous cell carcinomas.Methods Fifty cases of invasive cervical squamous cell carcinomas and 10 cases of normal cervical squamous epithelia were investigated with immunihistochemical technique. Results The overexpression of cyclin D1 and P53 in invasive cervical carcinomas was 70% and 50%, respectively. There was no overexpression of them in the control group. The overexpression of cyclin D1 in grade Ⅱ and Ⅲ was much higher than that in gradeⅠ(P<0.05). The overexpresson of cyclin D1 in stage Ⅲ of cervical carcinoma was significantly higher than that in stage Ⅱ (P<0.05). The overexpression of P53 in grade Ⅱ and grade Ⅲ of cervical carcinoma was remarkably higher than that in grade Ⅰ (P<0.05).Conclusion The action point of both cyclin D1 and P53 may be at G1/S transition. The overexpression of them was associated with development and progression of cervical carcinoma probably in different mechanisms and different pathways.展开更多
Objective:To study the alteration of cyclin D1,p16 and pRB in glioma,analyze proliferation and apoptosis of tumor cells,and discuss the pathogenesis of glioma. Methods:Thirty-seven glioma specimens were classified as...Objective:To study the alteration of cyclin D1,p16 and pRB in glioma,analyze proliferation and apoptosis of tumor cells,and discuss the pathogenesis of glioma. Methods:Thirty-seven glioma specimens were classified as astrocytoma(25 cases,including 7 fibrillary cases;6 protoplasmic cases;12 anaplastic cases),and glioblastoma(12 cases,including 4 GBM cases).Ten normal brain tissues were taken as controls.The expression of cyclin D1,p16 and pRB were detected by immunohistochemical method.Cellular proliferation was assessed by Ki-67 label index(Ki-67 LI).Cellular apoptosis was detected by TUNEL and apoptotic indices(AI)was calculated. Results:The alterations of three proteins were cyclin D1 overexpression(28/37,75.7%),p16 and pRB deletion(20/37,54.1 % and 12/37,32.4%),which were closely related to tumor types,particularly in malignant glioma.Ki-67 LI and AI were higher when pRB pathway was abnormal.Apoptosis was minor in astrocytic tumors(astrocytomas,0.010±0.002;glioblastomas,0.057±0.016). Conclusion:The abnormalities of cyclin D1/p16-pRB pathway correlated closely with pathogenesis of glioma.展开更多
Objective: To study the effects of tetrandrine (Tet) on phenotypic modulation of vascular smooth muscle cells (VSMCs) and expression of p38 mitogen-activated protein kinase (p38MAPK) as well as mitogen-activate...Objective: To study the effects of tetrandrine (Tet) on phenotypic modulation of vascular smooth muscle cells (VSMCs) and expression of p38 mitogen-activated protein kinase (p38MAPK) as well as mitogen-activated protein kinase phosphatase-1 (MKP-1) after vascular intimal injury. Methods: HE staining was used to analyze vascular morphology of sham-injured group, injured group and Tet-treated group at day 28. lmmunohistochemistry, Western blot and RT-PCR were respectively used to detect the expression change of smooth muscle a-actin (SMa-actin), proliferation cell nuclear antigen (PCNA), p38MAPK and MKP-1 of injured group and Tet group at days 7, 14 and 28 after balloon injury. Results: ① All layers of vascular wall in sham-injured group were intact at day 28. The neointimal area was significantly increased and the lumen area notably decreased in injured group at day 28. The neointimal proliferation in Tet treated group was less than that in injured group, and the lumen area of Tet group was significantly increased than that of injured group at day 28. ②Compared with the injured group, the expression of SMa-actin, PCNA, p38MAPK and MKP-1 of vascular wall in Tet group was no difference, and the neointimal proliferation condition was also basically as same as injured group at day 7 after injury. The expression of PCNA and p38MAKP in Tet group was obviously lower than that in injured group, and the expression of MKP-1 in Tet group was obviously higher than that in injured group at days 14 and 28 after injury. The expression of SMa-actin in Tet group was slightly higher than that in injured group at days 14 and 28 after injury. Conclusions: Tet could reduce neointimal proliferation by inhibiting VSMCs phenotypic modulation and p38MAPK signaling transduction pathway as well as its down regulation.展开更多
Objective To study the effects of P53, PCNA, Bc1-2 protein and their relationship in salivary adenoid cystic carclnoma(SACC). Methods These protelns were examlned by lmmunohistochemistry. Results overexpressions of Ps...Objective To study the effects of P53, PCNA, Bc1-2 protein and their relationship in salivary adenoid cystic carclnoma(SACC). Methods These protelns were examlned by lmmunohistochemistry. Results overexpressions of Ps, and PCNA were revealed in ACC samples, they were higher than those in (polymorphous adenomas) PA, but expression of Bc1-2 protein was not different between ACC and PA. In 3 subtypes of ACC, expressions of 3 proteins were different. Conciusion Mutations of P53, Bc1-2 may be involed in the occurrence of SACC, expression of PCNA and mutation of P53 may coexist in the development of the SACC.展开更多
Objective To investigate miR-183-5p targeting to forkhead box protein O1(FOXO1)and its corresponding effect on the proliferation,migration,invasion,and epithelial-mesenchymal transition(EMT)of non-small cell lung canc...Objective To investigate miR-183-5p targeting to forkhead box protein O1(FOXO1)and its corresponding effect on the proliferation,migration,invasion,and epithelial-mesenchymal transition(EMT)of non-small cell lung cancer(NSCLC)cells.Methods NSCLC tissues and adjacent normal tissues from 60 patients with NSCLC adenocarcinoma were obtained via pathological biopsy or intraoperative resection.Several cell lines were cultured in vitro,including the human normal lung epithelial cell line BEAS-2B and human NSCLC cell lines A549,SPCA-1,PC-9,and 95-D.miR-183-5p and FOXO1 mRNA expression in tissues and cells were detected by qRT-PCR;the corresponding correlations in NSCLC tissues were analyzed using the Pearson test,and the relationship between miR-183-5p expression and clinicopathological parameters was analyzed.The miR-183-5p-mediated regulation of FOXO1 was verified by bioinformatics prediction alongside double luciferase,RNA-binding protein immunoprecipitation(RIP)assay,and pull-down experiments.A549 cells were divided into control,anti-miR-NC,anti-miR-183-5p,miR-NC,miR-183-5p,miR-183-5p+pcDNA3.1,and miR-183-5p+pcDNA3.1-FOXO1 groups.Cell proliferation,invasion,migration,apoptosis,and cell cycle distribution were detected using an MTT assay,clone formation assay,Transwell assay,scratch test,and flow cytometry,respectively.The expression of EMT-related proteins in the cells was analyzed by western blotting.The effect of miR-185-3p silencing on the development of transplanted tumors was detected by analyzing tumor formation in nude mice.Results miR-183-5p expression was significantly higher in NSCLC tissues and cells than in adjacent normal tissues,whereas FOXO1 mRNA expression was significantly down-regulated.There was a significant negative correlation between miR-183-5p and FOXO1 mRNA in NSCLC tissues(P<0.05).Additionally,the expression of miR-183-5p was significantly correlated with tumor size,tumor differentiation,and tumor-node-metastasis stage in patients with NSCLC(P<0.05).miR-183-5p targeted and inhibited FOXO1 expression.Compared to the anti-miR-NC group,the cell proliferation,scratch healing rate,N-cadherin and vimentin protein expression,and the proportion of S phase cells were significantly lower in the anti-miR-183-5p group,whereas the protein expression of E-cadherin andα-catenin and the proportion of G0/G1 phase cells were significantly higher;additionally,the frequency of colony formation and invasion were significantly lower in the anti-miR-183-5p group(P<0.05).Compared to the miR-NC group,the cell proliferation,scratch healing rate,N-cadherin and vimentin protein expression,and the proportion of S phase cells in the miR-183-5p group were significantly higher,whereas the E-cadherin andα-catenin protein expression and the proportion of G0/G1 phase cells were significantly lower;furthermore,the frequency of colony formation and invasion were significantly higher in the miR-183-5p group(P<0.05).Compared with the miR-183-5p+pcDNA3.1 group,the OD value,scratch healing rate,N-cadherin and vimentin protein expression,and the proportion of S phase cells were significantly lower in the miR-183-5p+pcDNA3.1-FOXO1 group,whereas E-cadherin andα-catenin protein expression and the proportion of G0/G1 phase cells were significantly higher;additionally,the frequency of colony formation and invasion was significantly lower in the miR-183-5p+pcDNA3.1-FOXO1 group(P<0.05).Overall,silencing miR-185-3p inhibited the growth of transplanted tumors and promoted FOXO1 expression.Conclusion Overexpression of miR-183-5p can inhibit apoptosis and promote the proliferation,migration,invasion,and EMT,of NSCLC cells by down-regulating FOXO1 expression.展开更多
基金the National Natural Science Foundation of China (No. 30570627)
文摘Objective To investigate the protective effects of hydrogen peroxide preconditioning (HPP) on the pheochromocytoma (PC12) cells treated with 1-methyl-4-phenylpyridinium (MPP^+) and to explore the potential mechanisms. Methods The viability and apoptosis of PC 12 cells were determinded by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and 4′,6′-diamidino-2-phenylindole (DAPI) staining, respectively. The expressions of 14-3-3 protein and phospholylated p38 mitogen-activated protein kinase (MAPK) were determined by Western blot. Enzyme-linked immunosorbent assay (ELISA) was used to measure the activity of extracellular signal-regulated protein kinase 1/2 (ERK1/2). Results The cell viability decreased and the number of apoptotic cells increased dramatically in MPP^+ group compared with that in Control group. HPP induced a significant increase in cell viability and a marked decrease in population of apoptotic cells of the MPP^+- treated PC 12 cells, accompanied with up-regulation of 14-3-3 protein and increase of ERK 1/2 and p38 MAPK activities. The 14-3-3 protein expression was positively correlated with the phosphorylation of ERK1/2. Furthermore, inhibition of the ERK1/2 with PD98059 abolished the 14-3-3 protein up-regulation in PC 12 cells induced by HPP. Conclusion HPP protects PC 12 cells against MPP+ toxicity by up-regulating 14-3-3 protein expression through the ERK1/2 and p38 MAPK signaling pathways.
基金the National Natural Science Foundation of China (No. 30500189)
文摘Objective The present study aimed to explore the role of P2Y1 receptor in glial fibrillary acidic protein (GFAP) production and glial cell line-derived neurotrophic factor (GDNF) secretion of astrocytes under ischemic insult and the related signaling pathways. Methods Using transient right middle cerebral artery occlusion (tMCAO) and oxygen-glucose-serum deprivation for 2 h as the model of ischemic injury in vivo and in vitro, immunofluorescence, quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, enzyme linked immunosorbent assay (ELISA) were used to investigate location of P2Y1 receptor and GDNF, the expression of GFAP and GDNF, and the changes of signaling molecules. Results Blockage of P2Y1 receptor with the selective antagonist N^6-methyl-2′-deoxyadenosine 3′,5′-bisphosphate diammonium (MRS2179) reduced GFAP production and increased GDNF production in the antagonist group as compared with simple ischemic group both in vivo and in vitro. Oxygen-glucose-serum deprivation and blockage of P2Y1 receptor caused elevation of phosphorylated Akt and cAMP response element binding protein (CREB), and reduction of phosphorylated Janus kinase2 (JAK2) and signal transducer and activator of transcription3 (STAT3, Ser727). After blockage of P2Y1 receptor and deprivation of oxygen-glucose-serum, AG490 (inhibitor of JAK2) reduced phosphorylation of STAT3 (Ser727) as well as expression of GFAP; LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3-K), decreased phosphorylation of Akt and CREB; the inhibitor of mitogen-activated protein kinase kinase 1/2 (MEK 1/2) U0126, an important molecule of Ras/extracellular signal- regulated kinase (ERK) signaling pathway, decreased the phosphorylation of JAK2, STAT3 (Ser727), Akt and CREB. Conclusion These results suggest that P2Y1 receptor plays a role in the production of GFAP and GDNF in astrocytes under transient ischemic condition and the related signaling pathways may be JAK2/STAT3 and PI3-K/Akt/CREB, respectively, and that crosstalk probably exists between them.
文摘AIM: To study the relationship between interleukin-lbeta (IL-1β) up-regulating tissue inhibitor of matrix metalloproteinase-1 (TIMMP-1) mRNA expression and phosphorylation of both c-jun N-terminal kinase (INK) and p38 in rat heffatic stellate cells (HSC). METHODS: RT-PCR was performed to measure the expression of TIMMP-1 mRNA in rat HSC. Western blot was performed to measure IL-1β-induced JNK and p38 activities in rat HSC. RESULTS: TIMMP-1 mRNA expression (1.191± 0.079) was much higher after treatment with IL-1β (10 ng/mL) for 24 h than in control group (0.545±0.091) (P〈0.01). IL-1β activated INK and p38 in a time-dependent manner. After stimulation with IL-1β for 0, 5, 15, 30, 60 and 120 min, the INK activity was 0.982±0.299, 1.501±0.720, 2.133±0.882, 3.360±0.452, 2.181±0.789, and 1.385 ± 0.368, respectively. There was a significant difference in JNK activity at 15 min (P〈 0.01), 30 min (P〈 0.01) and 60 min (P〈0.01) in comparison to that at 0 min. The p38 activity was 1.061±0.310, 2.050±0.863, 2.380±0.573, 2.973±0.953, 2.421±0.793, and 1.755 ± 0.433 at the 6 time points (0, 5, 15, 30, 60 and 120 min) respectively. There was a significant difference in p38 activity at 5 min (P〈0.05), 15 min (P〈0.01), 30 min (P〈0.01) and 60 min (P〈0.01) compared to that at 0 min. TIMMP-1 mRNA expression trended to decrease in 3 groups pretreated with different concentrations of SP600125 (10 μmol/L, 1.022±0.113; 20 μmol/L, 0.869±0.070; 40 μmol/L, 0.666±0.123). Their decreases were all significant (P〈0.05, P〈0.01, P〈0.01) in comparison to control group (without SP600125 treatment, 1.163±0.107). In the other 3 groups pretreated with different concentrations of SB203580 (10 μmol/L, 1.507±0.099; 20 μmol/L, 1.698±0.107; 40 μmol/L, 1.857±0.054), the expression of TIMMP-1 mRNA increased. Their levels were higher than those in the control group (without SB203580 treatment, 1.027 ± 0.061) with a significant statistical significance (P〈 0.01). CONCLUSION: IL-1β has a direct action on hepatic fibrosis by up-regulating TIMMP-1 mRNA expression in ratessionin in rate HSC.JNK and p38 mitogen-activated protein kinases (MAPKs) are involved in IL-1β-induced TIMMP-1 gene expression, and play a distinct role in this process, indicating that p38 and .INK pathways cooperatively mediate TIMP-1 mRNA expression in rat HSC.
文摘The p27Kip1 is a cell cycle repressor protein that regulates primarily the cell cycle transition from G1 to S phase and hence the DNA replication is in the S phase and cell division in the M phase. Expression of p27Kip1 protein has dual roles for both cancer prevention and promotion. For example, numerous nutritional and chemopreventive anti-cancer agents specifically increase the expression of p27Kip1 protein without directly affecting the expression of any other cell cycle regulatory proteins. On the other hand, pro-cancer agents (like glucose, insulin and other growth factors frequently seen in obesity and/or diabetes) specifically decrease the expression of p27Kip1 protein without directly affecting the expression of any other cell cycle regulatory proteins. Unlike expression of any other cell cycle regulatory proteins, expression of p27Kip1 protein is very unusual. The mRNA of p27Kip1 has a very long and unusual 5’-untranslated region (from -575 to -1 in human). It appears that the 5’-untranslated region of p27Kip1 mRNA forms two alternative secondary structures. One increases the expression of p27Kip1 protein when anti-cancer agents are added and another decrease the expression of p27K1p1 when pro-cancer agents are added. For this short concept proposal, Dr. Albert Einstein’s “visualized thought experiments (German: Gedanken experiment)” were used as a fundamental tool for understanding how either anti- or pro-cancer agents bring the primary structure of the 5’-untranslated region of p27Kip1 mRNA into two alternative secondary structures, thereby either increasing or decreasing, respectively, the translation initiation of p27Kip1 protein.
基金Supported by The 13^(th)Five-Year Plan of Ministry of Science and Technology of the People’s Republic of China,No.2017ZX10302201-004-009,and No.2017ZX10203202-003Beijing Municipal Science and Technology Commission of Major Projects,No.D161100002716002,and No.D161100002716003.
文摘BACKGROUND Hepatitis B surface antigen(HBsAg)loss,a functional cure in patients with chronic hepatitis B(CHB)undergoing antiviral therapy,might be an ideal endpoint of antiviral treatment in clinical practice.The factors that contribute to the functional cure remain unclear,and the predictors of functional cure are worth exploring.The concentration and kinetics of soluble programmed death-1(sPD-1)in patients with CHB may play an important role in elucidating the immune response associated with functional cure after nucleos(t)ide analogs therapy.AIM To investigate the factors associated with HBsAg loss and explore the influence of sPD-1 Levels.METHODS This study analyzed the data and samples from patients with CHB who underwent antiviral treatment in a non-interventional observational study conducted at Peking University First Hospital in Beijing(between 2007 and 2019).All patients were followed up:Serum samples were collected every 3 mo during the first year of antiviral treatment and every 6 mo thereafter.Patients with positive hepatitis B e antigen levels at baseline and with available sequential samples who achieved HBsAg loss during antiviral treatment served as the case group.This case group(n=11)was further matched to 44 positive hepatitis B e anti patients without HBsAg loss as controls.The Spearman’s rank correlation test and receiver operating characteristic curves analysis were performed.RESULTS The sPD-1 Levels were higher in patients with HBsAg loss than in those without HBsAg loss from baseline to month 96,and the differences were significant between the groups at baseline(P=0.0136),months 6(P=0.0003),12(P<0.0001),24(P=0.0007),48(P<0.0001),and 96(P=0.0142).After 6 mo of antiviral treatment,the sPD-1 levels were positively correlated with alanine transaminase(ALT)levels(r=0.5103,P=0.0017),and the sPD-1 levels showed apparent correlation with ALT(r=0.6883,P=0.0192)and HBV DNA(r=0.5601,P=0.0703)levels in patients with HBsAg loss.After 12 mo of antiviral treatment,the sPD-1 levels also showed apparent correlation with ALT(r=0.8134,P=0.0042)and HBV DNA(r=0.6832,P=0.0205)levels in patients with HBsAg loss.The sPD-1 levels were negatively correlated with HBsAg levels in all patients after 12 mo of antiviral treatment,especially at 24(r=-0.356,P=0.0497)and 48(r=-0.4783,P=0.0037)mo.After 6 mo of antiviral treatment,the AUC of sPD-1 for HBsAg loss was 0.898(P=0.000),whereas that of HBsAg was 0.617(P=0.419).The cut-off value of sPD-1 was set at 2.34 log pg/mL;the sensitivity and specificity were 100%and 66.7%,respectively.CONCLUSION The sPD-1 levels at 6 mo can predict HBsAg loss after 144 mo of antiviral treatment.
文摘HIV-1 matrix protein (MA) is a multifunctional structural protein localized on N terminus of Gag precursor p55. MA participates in HIV-1 assembly as membranotropic part of Gag precursor as well as an individual protein spliced from Gag early in infection. MA is found in the nuclei of infected cells and in plasma membrane, the site of virus assembly, in association with viral genome RNA. MA mutated variant M4 which contains two changed amino acids in N-terminal regions is also associated with viral RNA, but it is localized in the nuclear and cytoskeleton fractions but not in the plasma membrane suggesting that the mutant is deprived of membranotropic signal and “sticks” in the nuclei an d cytoskeleton, its previous location sites. These data allow suggesting that MA involved into transmission of viral RNA is transported to plasma membrane by cytoskeleton.
文摘The mechanism and interaction among Rb/p16, Rb/E2F1 and HDAC1 proteins in gallbladder carcinoma were investigated. By using the immunoprecipitation method, the interactions among Rb, p16, E2F1, HDAC1 proteins in gallbladder carcinoma cell line (Mz-ChA-1) were studied. It was found that there were Rb and E2F1 proteins in the precipitates with anti-HDAC1, and there were HDAC1 and E2F1 proteins in the precipitate with anti-Rb. It was concluded that there are specific interactions among Rb, HDAC1 and E2F1 proteins in gallbladder carcinoma, indicating the existence of the direct Rb/E2F1/HDAC1 signal transduction pathway. There is no direct relationship between p16 proteins with Rb, HDAC1, and E2F1 proteins.
基金supported by the NHMRC-ARC Dementia Research Development Fellowship Grant(AP1102977)an Australian Government Research Training Program(RTS)Scholarship。
文摘Amyotrophic lateral sclerosis and frontotemporal lobar degeneration are multifaceted diseases with genotypic,pathological and clinical overlap.One such overlap is the presence of SQSTM1/p62 mutations.While traditionally mutations manifesting in the ubiquitin-associated domain of p62 were associated with Paget’s disease of bone,mutations affecting all functional domains of p62 have now been identified in amyotrophic lateral sclerosis and frontotemporal lobar degeneration patients.p62 is a multifunctional protein that facilitates protein degradation through autophagy and the ubiquitin-proteasome system,and also regulates cell survival via the Nrf2 antioxidant response pathway,the nuclear factor-kappa B signaling pathway and apoptosis.Dysfunction in these signaling and protein degradation pathways have been observed in amyotrophic lateral sclerosis and frontotemporal lobar degeneration,and mutations that affect the role of p62 in these pathways may contribute to disease pathogenesis.In this review we discuss the role of p62 in these pathways,the effects of p62 mutations and the effect of mutations in the p62 modulator TANK-binding kinase 1,in relation to amyotrophic lateral sclerosis-frontotemporal lobar degeneration pathogenesis.
基金supported by a grant from the National Natural Sciences Foundation of China,No.81030019
文摘Alterations in embryonic neural stem cells play crucial roles in the pathogenesis of amyotrophic lateral sclerosis. We hypothesized that embryonic neural stem cells from SOD1G93A individuals might be more susceptible to oxidative injury, resulting in a propensity for neurodegeneration at later stages. In this study, embryonic neural stem cells obtained from human superoxide dis- mutase 1 mutant (SOD1G93A) and wild-type (SOD1wv) mouse models were exposed to H202. We assayed cell viability with mitochondrial succinic dehydrogenase colorimetric reagent, and measured cell apoptosis by flow cytometry. Moreover, we evaluated the expression of the adenos- ine monophosphate-activated protein kinase (AMPK) ct-subunit, paired box 3 (Pax3) protein, and p53 in western blot analyses. Compared with SOD1wr cells, SOD1~93A embryonic neural stem cells were more likely to undergo H202-induced apoptosis. Phosphorylation of AMPKct in SOD1G93A cells was higher than that in SOD1wr cells. Pax3 expression was inversely correlated with the phosphorylation levels of AMPKct. p53 protein levels were also correlated with AMPKct phosphorylation levels. Compound C, an inhibitor of AMPKa, attenuated the effects of H20~. These results suggest that embryonic neural stem cells from SOD1C93A mice are more susceptible to apoptosis in the presence of oxidative stress compared with those from wild-type controls, and the effects are mainly mediated by Pax3 and p53 in the AMPKa pathway.
基金Supported by A Grant-in-Aid from the Ministry of HealthLabour and Welfare of Japan+2 种基金No.KHD1017by that from JSTPRESTO
文摘AIM: To identify kinases involved in phenotype regulation of vascular endothelial cells(VECs): Proproliferative G-protein signaling 5(RGS5)^(high)(typeⅠ) vs anti-proliferative RGS5^(low)(typeⅡ) VECs.METHODS: Proteomic kinase assays were performed to identify the crucial kinase involved in the phenotype regulation of human VECs using typeⅠ VECs, which promotes the proliferation of human vascular smooth muscle cells(VSMCs), and typeⅡ VECs, which suppress the proliferation of human VSMCs. The assays were performed using multiple pairs of typeⅠ and typeⅡ VECs to obtain the least number of candidates. The involvement of the candidate kinases was verified by evaluating the effects of their specific inhibitors on the phenotype regulation of human VECs as well as the expression levels of regulator of RGS5, which is the causative gene for the "typeⅡ to typeⅠ" phenotype conversion of human VECs. RESULTS: p38α mitogen-activated protein kinase(p38α MAPK) was the only kinase that showed distinctive activities between typeⅠ and typeⅡ VECs: p38α MAPK activities were low and high in type-Ⅰand typeⅡ VECs, respectively. We found that an enforced expression of RGS5 indeed lowered p38α MAPK activitiesin typeⅡ VECs. Furthermore, treatments with a p38α MAPK inhibitor nullified the anti-proliferative potential in typeⅡ VECs. Interestingly, MAPK inhibitor treatments enhanced the induction of RGS5 gene. Thus, there is a vicious cycle between "RGS5 induction" and "p38α MAPK inhibition", which can explain the unidirectional process in the stress-induced "typeⅡ to typeⅠ" conversions of human VECs. To understand the upstream signaling of RGS5, which is known as an inhibitory molecule against the G protein-coupled receptor(GPCR)-mediated signaling, we examined the effects of RGS5 overexpression on the signaling events from sphingosine-1-phosphate(S1P) to N-cadherin, because S1 P receptors belong to the GPCR family gene and N-cadherin, one of their downstream effectors, is reportedly involved in the regulation of VEC-VSMC interactions. We found that RGS5 specifically bound with S1P1. Moreover, N-cadherin localization at intercellular junctions in typeⅡ VECs was abolished by "RGS5 overexpression" and "p38α MAPK inhibition".CONCLUSION: p38α MAPK plays crucial roles in "type-Ⅰ vs type-Ⅱ" phenotype regulations of human VECs at the downstream of RGS5.
基金Supported by the National Natural Science Foundation of China,No.81072040the Specialized Research Fund for the Doctoral Program of Ningxia Medical University
文摘AIM: To investigate the mechanism of calcyclin binding protein/Siah-1 interacting protein(Cacy BP/SIP) nuclear translocation in promoting the proliferation of gastric cancer(GC) cells. METHODS: The effect of Cacy BP/SIP nuclear translocation on cell cycle was investigated by cell cycle analysis. Western blot analysis was used to assess the change in expression of cell cycle regulatory proteins and proteasome-mediated degradation of p27Kip1. Coimmunoprecipitation(co-IP) analysis was performed to examine the binding of Cacy BP/SIP with Skp1. A Cacy BP/SIP truncation mutant which lacked the Skp1 binding site was constructed and fused to a fluorescent protein. Subsequently, the effect on Skp1 binding with the fusion protein was examined by co-IP, while localization of fluorescent fusion protein observed by confocal laser microscopy, and change in p27Kip1protein expression assessed by Western blot analysis.RESULTS: Cacy BP/SIP nuclear translocation induced by gastrin promoted progression of GC cells from G1 phase. However, while Cacy BP/SIP nuclear translocation was inhibited using si RNA to suppress Cacy BP/SIP expression, cell cycle was clearly inhibited. Cacy BP/SIP nuclear translocation significantly decreased the level of cell cycle inhibitor p27Kip1, increased Cyclin E protein expression whereas the levels of Skp1, Skp2, and CDK2 were not affected. Upon inhibition of Cacy BP/SIP nuclear translocation, there were no changes in protein levels of p27Kip1 and Cyclin E, while p27Kip1 decrease could be prevented by the proteasome inhibitor MG132. Moreover, Cacy BP/SIP was found to bind to Skp1 by immunoprecipitation, an event that was abolished by mutant Cacy BP/SIP, which also failed to stimulate p27Kip1 degradation, even though the mutant could still translocate into the nucleus.CONCLUSION: Cacy BP/SIP nuclear translocation contributes to the proliferation of GC cells, and Cacy BP/SIP exerts this effect, at least in part, by stimulating ubiquitin-mediated degradation of p27Kip1.
基金This work was supported by the National Natural Science Foundation of China(No.30100220)
文摘Objective: Impaired signal transduction is associated with tumorigenesis and progression of various kinds of human cancers. Transforming growth factor (TGF)-beta/Smad and ras-mitogen activated protein kinase (MAPK) are two major signal transduction pathways for adjusting cell proliferation and differentiation. Little is known about TGF-beta/Smad4 in non-small cell lung cancer (NSCLC). Hereby, we investigated the expression of Smad4 in NSCLC, its correlation with MAPK proteins (including p38, ERK1 and JNK1 proteins) and their clinical significance in NSCLC. Methods: The expressions of Smad4, p38, ERK1 and JNK1 were detected at protein level with Western blotting and immunohistochemistry, at transcription level with RT-PCR. Statistical analysis was performed for the comparisons of expressions of Smad4, p38, ERK1 and JNK1, and their correlation with various clinicopathological parameters and the prognosis of NSCLC. Results: The levels of protein and mRNA expression of Smad4 in lung cancer tissues were significantly lower than in normal tissues (P〈0.05). All these four proteins were associated with TNM staging. There was a strongly negative correlation between p38 and Smad4. Expressions of Smad4, p38 and JNK1, as well as tumor differentiation and staging were significantly correlated with the prognosis of NSCLC by univariate analysis. By multivariate analysis, only Smad4, p38, tumor differentiation and staging were correlated with the prognosis. Taken together, the negative expression of p38 and positive expression of Smad4 were associated with a better prognosis of NSCLC. Conclusion: Smad4 could be of vital importance for the initiation and development of NSCLC. The expression of Smad4 might be inhibited by p38, supporting a cross-talk between main proteins of TGF-beta/Smad and ras-MAPK signal transduction pathways. Smad4 and p38 could be possible prognostic factors for NSCLC.
文摘Objective To investigate the significance of overexpresson of cyclin D1 and P53 protein in cervical squamous cell carcinomas.Methods Fifty cases of invasive cervical squamous cell carcinomas and 10 cases of normal cervical squamous epithelia were investigated with immunihistochemical technique. Results The overexpression of cyclin D1 and P53 in invasive cervical carcinomas was 70% and 50%, respectively. There was no overexpression of them in the control group. The overexpression of cyclin D1 in grade Ⅱ and Ⅲ was much higher than that in gradeⅠ(P<0.05). The overexpresson of cyclin D1 in stage Ⅲ of cervical carcinoma was significantly higher than that in stage Ⅱ (P<0.05). The overexpression of P53 in grade Ⅱ and grade Ⅲ of cervical carcinoma was remarkably higher than that in grade Ⅰ (P<0.05).Conclusion The action point of both cyclin D1 and P53 may be at G1/S transition. The overexpression of them was associated with development and progression of cervical carcinoma probably in different mechanisms and different pathways.
文摘Objective:To study the alteration of cyclin D1,p16 and pRB in glioma,analyze proliferation and apoptosis of tumor cells,and discuss the pathogenesis of glioma. Methods:Thirty-seven glioma specimens were classified as astrocytoma(25 cases,including 7 fibrillary cases;6 protoplasmic cases;12 anaplastic cases),and glioblastoma(12 cases,including 4 GBM cases).Ten normal brain tissues were taken as controls.The expression of cyclin D1,p16 and pRB were detected by immunohistochemical method.Cellular proliferation was assessed by Ki-67 label index(Ki-67 LI).Cellular apoptosis was detected by TUNEL and apoptotic indices(AI)was calculated. Results:The alterations of three proteins were cyclin D1 overexpression(28/37,75.7%),p16 and pRB deletion(20/37,54.1 % and 12/37,32.4%),which were closely related to tumor types,particularly in malignant glioma.Ki-67 LI and AI were higher when pRB pathway was abnormal.Apoptosis was minor in astrocytic tumors(astrocytomas,0.010±0.002;glioblastomas,0.057±0.016). Conclusion:The abnormalities of cyclin D1/p16-pRB pathway correlated closely with pathogenesis of glioma.
文摘Objective: To study the effects of tetrandrine (Tet) on phenotypic modulation of vascular smooth muscle cells (VSMCs) and expression of p38 mitogen-activated protein kinase (p38MAPK) as well as mitogen-activated protein kinase phosphatase-1 (MKP-1) after vascular intimal injury. Methods: HE staining was used to analyze vascular morphology of sham-injured group, injured group and Tet-treated group at day 28. lmmunohistochemistry, Western blot and RT-PCR were respectively used to detect the expression change of smooth muscle a-actin (SMa-actin), proliferation cell nuclear antigen (PCNA), p38MAPK and MKP-1 of injured group and Tet group at days 7, 14 and 28 after balloon injury. Results: ① All layers of vascular wall in sham-injured group were intact at day 28. The neointimal area was significantly increased and the lumen area notably decreased in injured group at day 28. The neointimal proliferation in Tet treated group was less than that in injured group, and the lumen area of Tet group was significantly increased than that of injured group at day 28. ②Compared with the injured group, the expression of SMa-actin, PCNA, p38MAPK and MKP-1 of vascular wall in Tet group was no difference, and the neointimal proliferation condition was also basically as same as injured group at day 7 after injury. The expression of PCNA and p38MAKP in Tet group was obviously lower than that in injured group, and the expression of MKP-1 in Tet group was obviously higher than that in injured group at days 14 and 28 after injury. The expression of SMa-actin in Tet group was slightly higher than that in injured group at days 14 and 28 after injury. Conclusions: Tet could reduce neointimal proliferation by inhibiting VSMCs phenotypic modulation and p38MAPK signaling transduction pathway as well as its down regulation.
文摘Objective To study the effects of P53, PCNA, Bc1-2 protein and their relationship in salivary adenoid cystic carclnoma(SACC). Methods These protelns were examlned by lmmunohistochemistry. Results overexpressions of Ps, and PCNA were revealed in ACC samples, they were higher than those in (polymorphous adenomas) PA, but expression of Bc1-2 protein was not different between ACC and PA. In 3 subtypes of ACC, expressions of 3 proteins were different. Conciusion Mutations of P53, Bc1-2 may be involed in the occurrence of SACC, expression of PCNA and mutation of P53 may coexist in the development of the SACC.
文摘Objective To investigate miR-183-5p targeting to forkhead box protein O1(FOXO1)and its corresponding effect on the proliferation,migration,invasion,and epithelial-mesenchymal transition(EMT)of non-small cell lung cancer(NSCLC)cells.Methods NSCLC tissues and adjacent normal tissues from 60 patients with NSCLC adenocarcinoma were obtained via pathological biopsy or intraoperative resection.Several cell lines were cultured in vitro,including the human normal lung epithelial cell line BEAS-2B and human NSCLC cell lines A549,SPCA-1,PC-9,and 95-D.miR-183-5p and FOXO1 mRNA expression in tissues and cells were detected by qRT-PCR;the corresponding correlations in NSCLC tissues were analyzed using the Pearson test,and the relationship between miR-183-5p expression and clinicopathological parameters was analyzed.The miR-183-5p-mediated regulation of FOXO1 was verified by bioinformatics prediction alongside double luciferase,RNA-binding protein immunoprecipitation(RIP)assay,and pull-down experiments.A549 cells were divided into control,anti-miR-NC,anti-miR-183-5p,miR-NC,miR-183-5p,miR-183-5p+pcDNA3.1,and miR-183-5p+pcDNA3.1-FOXO1 groups.Cell proliferation,invasion,migration,apoptosis,and cell cycle distribution were detected using an MTT assay,clone formation assay,Transwell assay,scratch test,and flow cytometry,respectively.The expression of EMT-related proteins in the cells was analyzed by western blotting.The effect of miR-185-3p silencing on the development of transplanted tumors was detected by analyzing tumor formation in nude mice.Results miR-183-5p expression was significantly higher in NSCLC tissues and cells than in adjacent normal tissues,whereas FOXO1 mRNA expression was significantly down-regulated.There was a significant negative correlation between miR-183-5p and FOXO1 mRNA in NSCLC tissues(P<0.05).Additionally,the expression of miR-183-5p was significantly correlated with tumor size,tumor differentiation,and tumor-node-metastasis stage in patients with NSCLC(P<0.05).miR-183-5p targeted and inhibited FOXO1 expression.Compared to the anti-miR-NC group,the cell proliferation,scratch healing rate,N-cadherin and vimentin protein expression,and the proportion of S phase cells were significantly lower in the anti-miR-183-5p group,whereas the protein expression of E-cadherin andα-catenin and the proportion of G0/G1 phase cells were significantly higher;additionally,the frequency of colony formation and invasion were significantly lower in the anti-miR-183-5p group(P<0.05).Compared to the miR-NC group,the cell proliferation,scratch healing rate,N-cadherin and vimentin protein expression,and the proportion of S phase cells in the miR-183-5p group were significantly higher,whereas the E-cadherin andα-catenin protein expression and the proportion of G0/G1 phase cells were significantly lower;furthermore,the frequency of colony formation and invasion were significantly higher in the miR-183-5p group(P<0.05).Compared with the miR-183-5p+pcDNA3.1 group,the OD value,scratch healing rate,N-cadherin and vimentin protein expression,and the proportion of S phase cells were significantly lower in the miR-183-5p+pcDNA3.1-FOXO1 group,whereas E-cadherin andα-catenin protein expression and the proportion of G0/G1 phase cells were significantly higher;additionally,the frequency of colony formation and invasion was significantly lower in the miR-183-5p+pcDNA3.1-FOXO1 group(P<0.05).Overall,silencing miR-185-3p inhibited the growth of transplanted tumors and promoted FOXO1 expression.Conclusion Overexpression of miR-183-5p can inhibit apoptosis and promote the proliferation,migration,invasion,and EMT,of NSCLC cells by down-regulating FOXO1 expression.