Effects of invigorating-spleen and anticancer prescription on extracellular signal-regulated kinase/mitogen-activated protein kinase signaling pathway in colon cancer mice model

BACKGROUND Colon cancer(CC)is one of the most common malignant tumors in the gastrointestinal system.Overall,CC had the third highest incidence but the second highest mortality rate globally in 2020.Nowadays,CC is mainly treated with capecitabine chemotherapy regimen,supplemented by radiotherapy,immunotherapy and targeted therapy,but there are still limitations,so Chinese medicine plays an important role.AIM To investigate the effects of invigorating-spleen and anticancer prescription(ISAP)on body weight,tumor inhibition rate and expression levels of proteins in extracellular-signal-regulated kinase(ERK)/mitogen-activated protein kinase(MAPK)signaling pathway in CC mice model.METHODS The CC mice model were established and the mice were randomly divided into 5 groups,including the control group,capecitabine group,the low-dose,mediumdose and high-dose groups of ISAP,with 8 mice in each group,respectively.After 2 weeks of intervention,the body weight and tumor inhibition rate of mice were observed,and the expression of RAS,ERK,phosphorylated ERK(p-ERK),C-MYC and matrix metalloproteinase 2(MMP2)proteins in the tissues of tumors were detected.RESULTS Compared with the control group,the differences of body weight before and after treatment was much smaller in the groups of ISAP,with the smallest difference in the high-dose group of ISAP,while the capecitabine group had the greatest difference,indicating ISAP had a significant inhibiting effect on the growth of transplanted tumor in mice.The expression of RAS protein was decreased in the low-and medium-dose groups of ISAP,and the change of p-ERK was significant in the medium-and high-dose groups of ISAP.MMP2 protein expression was significantly decreased in both the low-dose and medium-dose groups of ISAP.There were no significant changes in ERK in the ISAP group compared to the capecitabine group,while RAS,MMP2,and C-MYC protein expression were reduced in the ISAP group.The expression level of C-MYC protein decreased after treated with ISAP,and the decrease was the most significant in the medium-dose group of ISAP.CONCLUSION ISAP has a potential inhibiting effect on transplanted tumor in mice,and could maintain the general conditions,physical strength and body weight of mice.The expression levels of RAS,p-ERK,MMP2 and c-myc were also decreased to a certain extent.By inhibiting the expression of upstream proteins,the expression levels of downstream proteins in ERK/MAPK signaling pathway were significantly decreased.Therefore,it can be concluded that ISAP may exert an anti-tumor effect by blocking the ERK/MAPK signaling pathway and inhibiting the expression of MMP2 and c-myc proteins.

Influence of Ren and Du meridian electro-acupuncture on neural stem cell proliferation and extracellular signal-regulated kinase pathway in a rat model of focal cerebral ischemia injury

BACKGROUND： Studies have shown that electro-acupuncture at the Ren meridian could improve proliferation of subventricular zone neural stem cells in cerebral-ischemic rats. However, there are few reports on the influence of electro-acupuncture at the Du meridian on neural stem cell proliferation. OBJECTIVE： To observe the influence of electro-acupuncture at Ren and Du meridians on neural stem cell proliferation in the subventricular zone and altered signal transduction in cerebral ischemia rats. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Laboratory of Human Anatomy, Medical College of Sun Yat-sen University from May 2006 to February 2008. MATERIALS： Mouse anti-rat bromodeoxyuridine （BrdU） monoclonal antibody was provided by Sigma, USA; mouse anti-rat nestin monoclonal antibody and extracellular signal-regulated protein kinase （ERK） specific inhibitor PD98059 were provided by Calbiochem, Germany; acupuncture needle was provided by Suzhou Acupuncture Supplies, China. METHODS： A total of 126 rats were randomly assigned to four groups： model （n = 36）, Du meridian （n = 36）, Ren/Du meridian （n = 36）, and Ren/Du meridian ＋ PD98059 （n = 18）. Rats in the Ren/Du meridian ＋ PD98059 group were observed on days 7 （n = 6） and 14 （n = 12） after cerebral ischemia injury. Rats in the model, Du meridian, and Ren/Du meridian groups were observed on days 7, 14, and 28 after cerebral ischemia injury, with 12 rats per group at each time point. Thread occlusion was used to establish middle cerebral artery occlusion models. Electro-acupuncture was performed at Renzhong （DU 26） and Baihui （DU 20） acupoints in the Du meridian group, as well as Chengjiang （RN 24）, Guanyuan （RN 4）, Renzhong, and Baihuiacupoints in the Ren/Du meridian and Ren/Du meridian ＋ PD98059 groups 2 days after model establishment. In addition, electro-acupuncture stimulation with disperse-dense waves was performed, with 30 Hz disperse wave, 100 Hz dense wave, and 5 V intensity for 20 minutes. Rats in the Ren/Du meridian ＋ PD98059 group were treated with 0.2 pg PD98059 injection into the subventricular zone, 2 pL per rat. Rats in the model group were not treated with electro-acupuncture. MAIN OUTCOME MEASURES： BrdU/nestin immunofluorescent staining was used to detect proliferating neural stem cells in the subventricular zone of cerebral ischemia rats; Western blot was used to determine phosphorylated ERK1 and 2 （pERK1/2） expression in the subventricular zone. RESULTS： On days 14 and 28 after cerebral ischemia, there were significantly more BrdU-positive and BrdU/nestin-positive cells in the Ren/Du meridian group compared with the Du meridian group （P 〈 0.05）. PD98059 decreased the number of BrdU-positive and BrdU/nestin-positive cells induced by electro-acupuncture at the/：ten and Du meridians （P 〈 0.05）. On days 7, 14, and 28 after treatment, pERK1/2 expression was significantly greater in the Du meridian and Ren/Du meridian groups compared with the model group （P 〈 0.05）. The promoting effect of electro-acupuncture at Ren and Du meridians on ERK1/2 phosphorylation was superior to electro-acupuncture at the Du meridian alone on day 14 after model induction （P 〈 0.05）. However, PD98059 completely abolished the promoting effect of electro-acupuncture at Ren/Du meridians on pERK1/2 expression （P 〈 0.05）. CONCLUSION： Electro-acupuncture at Ren and Du meridians increased proliferation of subventricular zone neural stem cells, which was related to activation of the ERK pathway in a rat model of cerebral ischemia injury.

XAF1 mediates apoptosis through an extracellular signal-regulated kinase pathway in colon cancer

Background:XIAP-associated factor 1(XAF1)negatively regulates the function of the X-linked inhibitor of apoptosis protein(XIAP),a member of the IAP family that exerts antiapoptotic effects.The extracellular signal-regulated kinase(ERK)pathway is thought to increase cell proliferation and to protect cells from apoptosis.The aim of the study was to investigate the correlation between the ERK1/2 signaling pathway and XAF1 in colon cancer.Methods:Four human colon cancer cell lines,HCT1116 and Lovo(wildtype p53),DLD1 and SW1116(mutant p53),were used.Lovo stable transfectants with XAF1 sense and antisense were established.The effects of dominant-negative MEK1(DN-MEK1)and MEK-specific inhibitor U0126 on the ERK signaling pathway and expression of XAF1 and XIAP proteins were determined.The transcription activity of core XAF1 promoter was assessed by dual luciferase reporter assay.Cell proliferation was measured by MTT assay.Apoptosis was determined by Hoechst 33258 staining.Results:U0126 increased the expression of XAF1 in a time-and dose-dependent manner.A similar result was obtained in cells transfected with DN-MEK1 treatment.Conversely,the expression of XIAP was down-regulated.Activity of the putative promoter of the XAF1 gene was significantly increased by U0126 treatment and DN-MEK1 transient transfection.rhEGF-stimulated phosphorylation of ERK appeared to have little or no effect on XAF1 expression.Overexpression of XAF1 was more sensitive to U0126-induced apoptosis,whereas down-regulation of XAF1 by antisense reversed U0126-induced inhibition of cell proliferation.Conclusions:XAF1 expression was up-regulated by inhibition of the ERK1/2 pathway through transcriptional regulation,which required de novo protein synthesis.The results suggest that XAF1 mediates apoptosis induced by the ERK1/2 pathway in colon cancer.

Physiological roles of mitogen-activated-protein-kinase-activated p38-regulated/activated protein kinase

Mitogen-activated protein kinases(MAPKs)are a family of proteins that constitute signaling pathways involved in processes that control gene expression,cell division, cell survival,apoptosis,metabolism,differentiation and motility.The MAPK pathways can be divided into conventional and atypical MAPK pathways.The first group converts a signal into a cellular response through a relay of three consecutive phosphorylation events exerted by MAPK kinase kinases,MAPK kinase,and MAPK.Atypical MAPK pathways are not organized into this three-tiered cascade.MAPK that belongs to both conventional and atypical MAPK pathways can phosphorylate both non-protein kinase substrates and other protein kinases.The latter are referred to as MAPK-activated protein kinases.This review focuses on one such MAPK-activated protein kinase,MAPK-activated protein kinase 5(MK5)or p38-regulated/activated protein kinase(PRAK).This protein is highly conserved throughout the animal kingdom and seems to be the target of both conventional and atypical MAPK pathways.Recent findings on the regulation of the activity and subcellular localization,bona fide interaction partners and physiological roles of MK5/PRAK are discussed.

Increased expression of mitogen-activated protein kinase and its upstream regulating signal in human gastric cancer

AIM: To investigate the expression of mitogen-activated protein kinases (MAPKs) and its upstream protein kinase in human gastric cancer and to evaluate the relationship between protein levels and clinicopathological parameters. METHODS: Western blot was used to measure the expression of extracellular signal-regulated kinase (ERK)-1, ERK-2, ERK-3, p38 and mitogen or ERK activated protein kinaseMEK-1 proteins in surgically resected gastric carcinoma, adjacent normal mucosa and metastatic lymph nodes from 42 patients. Immunohistochemistry was employed for their localization. RESULTS: Compared with normal tissues, the protein levels of ERK-1 (integral optical density value 159 526?5 760 vs 122 807±65 515, P= 0.001), ERK-2 (168 471±95 051 vs 120 469±72 874, P<0.001), ERK-3 (118 651±71 513 vs 70 934±68 058,P<0.001), P38 (104 776±51 650 vs 82 930±40 392, P= 0.048) and MEK-1 (116 486±45 725 vs 101 434±49 387, P = 0.027) were increased in gastric cancer tissues. Overexpression of ERK-3 was correlated to TNM staging [average ratio of integral optic density (IOD)tumor: IODnormal in TNM I, II, III, IV tumors was 1.43±0.34, 5.08±3.74, 4.99±1.08, 1.44±1.02, n = 42, P= 0.023] and serosa invasion (4.31±4.34 vs 2.00±2.03, P = 0.037). In poorly differentiated cancers (n = 33), the protein levels of ERK-1 and ERK-2 in stage III and IV tumors were higher than those in stage I and II tumors (2.64+3.01 vs 1.01±0.33, P= 0.022; 2.05±1.54 vs1.24±0.40, P= 0.030). Gastric cancer tissues with either lymph node involvement (2.49±2.91 vs1.03±0.36, P= 0.023; 1.98±1.49vs1.24±0.44, P= 0.036) or serosa invasion (2.39±2.82 vs 1.01±0.35, P= 0.022; 1.95±1.44 vs1.14±0.36, P=0.015) expressed higher protein levels of ERK-1 and ERK-2. In Borrmann II tumors, expression of ERK-2 and ERK-3 was increased compared with Borrmann III tumors (2.57±1.86 vs1.23±0.60, P= 0.022; 5.50±5.05 vs1.83±1.21, P= 0.014). Borrmann IV tumors expressed higher p38 protein levels. No statistically significant difference in expression of MAPKs was found when stratified to tumor size or histological grade (P>0.05). Protein levels of ERK-2, ERK-3 and MEK-1 in metastatic lymph nodes were 2-7 folds higher than those in adjacent normal mucosa. The immunohistochemistry demonstrated that ERK-1, ERK-2, ERK-3, p38 and MEK-1 proteins were mainly localized in cytoplasm. The expression of MEK-1 in gastric cancer cells metastasized to lymph nodes was higher than that of the primary site. CONCLUSION: MAPKs, particularly ERK subclass are overexpressed in the majority of gastric cancers. Overexpression of ERKs is correlated to TNM staging, serosa invasion, and lymph node involvement. The overexpression of p38 most likely plays a prominent role in certain morphological subtypes of gastric cancers. MEK-1 is also overexpressed in gastric cancer, particularly in metastatic lymph nodes. Upregulation of MARK signal transduction pathways may play an important role in tumorigenesis and metastatic potential of gastric cancer.

Mitogen activated protein kinase signaling pathways participate in the active principle region of Buyang Huanwu decoction-induced differentiation of bone marrow mesenchymal stem cells

Our preliminary studies confirmed that an active principle region of Buyang Huanwu decoction, comprising alkaloid, polysaccharide, aglycon, glucoside and volatile oil, can induce bone marrow mesenchymal stem cell differentiation into neurons. Mitogen-activated protein kinase signaling was identified as one of the key pathways underlying this differentiation process. The present study shows phosphorylated extracellular signal-regulated protein kinase and phosphorylated p38 protein expression was increased after differentiation. Cellular signaling pathway blocking agents, PD98059 and SB203580, inhibited extracellular signal-regulated protein kinase and p38 in mitogen-activated protein kinase signaling pathways respectively, mRNA and protein expression of the neuronal marker, neuron specific enolase, and neural stem cell marker, nestin, were decreased in bone marrow mesenchymal stem cells after treatment with the active principle region of Buyang Huanwu decoction. Experimental findings indicate that, extracellular signal-regulated protein kinase and p38 in mitogen-activated protein kinase signaling pathways participate in bone marrow mesenchymal stem cell differentiation into neuron-like cells, induced by the active principle region of Buyang Huanwu decoction.

Ceramide from sphingomyelin hydrolysis differentially mediates mitogen-activated protein kinases (MAPKs) activation following cerebral ischemia in rat hippocampal CA1 subregion

Objective： To explore the role that ceramide plays in the activation of mitogen-activated protein kinases （MAPKs） during cerebral ischemia and reperfusion. Methods： Rats were subjected to ischemia by the fourvessel occlusion （4-VO） method. The sphingomyelinase inhibitor TPCK was administered to the CA1 subregion of the rat hippocampus before inducing ischemia. Western blot was used to examine the activity of extracellular- signal regulated kinase （ERK） and c-Jun N-terminal protein kinase （JNK） using antibodies against ERK, JNK and diphosphorylated ERK and JNK. Results： At lh reperfusion post-ischemia, JNK reached its peak activity while ERK was undergoing a sharp inactivation （P 〈 0.05）. The level of diphosphorylated JNK was significantly reduced but the sharp inactivation of ERK was visibly reversed （P 〈 0.05） by the sphingomyelinase inhibitor. Conclusion： The ceramide signaling pathway is up-regulated through sphingomyelin hydrolysis in brain ischemia, promoting JNK activation and suppressing ERK activation, culminating in the ischemic lesion.

Serine-threonine protein kinase activation may be an effective target for reducing neuronal apoptosis after spinal cord injury

The signaling mechanisms underlying ischemia-induced nerve cell apoptosis are poorly understood. We investigated the effects of apoptosis-related signal transduction pathways following ischemic spinal cord injury, including extracellular signal-regulated kinase（ERK）, serine-threonine protein kinase（Akt） and c-Jun N-terminal kinase（JNK） signaling pathways. We established a rat model of acute spinal cord injury by inserting a catheter balloon in the left subclavian artery for 25 minutes. Rat models exhibited notable hindlimb dysfunction. Apoptotic cells were abundant in the anterior horn and central canal of the spinal cord. The number of apoptotic neurons was highest 48 hours post injury. The expression of phosphorylated Akt（pAkt） and phosphorylated ERK（p-ERK） increased immediately after reperfusion, peaked at 4 hours（p-Akt） or 2 hours（p-ERK）, decreased at 12 hours, and then increased at 24 hours. Phosphorylated JNK expression reduced after reperfusion, increased at 12 hours to near normal levels, and then showed a downward trend at 24 hours. Pearson linear correlation analysis also demonstrated that the number of apoptotic cells negatively correlated with p-Akt expression. These findings suggest that activation of Akt may be a key contributing factor in the delay of neuronal apoptosis after spinal cord ischemia, particularly at the stage of reperfusion, and thus may be a target for neuronal protection and reduction of neuronal apoptosis after spinal cord injury.

Calcitonin gene-related peptide induces proliferation and monocyte chemoattractant protein-1 expression via extracellular signal-regulated kinase activation in rat osteoblasts

Background Calcitonin gene-related peptide （CGRP）, a sensory neuropeptide, affects osteoblast proliferation and bone formation. However, the mechanisms are not fully understood. Monocyte chemoattractant protein-1 （MCP-1） is a chemokine that stimulates the migration of monocytes and plays important roles in regulating bone remolding during fracture repair. In this study, we investigated the effects of CGRP on proliferation and MCP-1 expression in cultured rat osteoblasts. Methods Primary rat osteoblasts were isolated from fetal rats calvariae. Cells were exposed to gradient concentrations （10^-9 to 10^-7 mol/L） of CGRP. Protein and mRNA levels of MCP-1 were quantified by Western blotting and semiquantitative reverse transcdption-polymerase chain reaction, respectively. The protein level of MCP-1 was investigated and compared in cell culture media by enzyme linked immunosorbent assay （ELISA）. Phospho-extracellular signal-regulated kinase （ERK） expression was detected by Western blotting. Cell proliferative activity was measured by 3-（4,5-dimethylthiazol-2-yl）-2, 5-diphenyl tetrazolium bromide （MTT） and BrdU assay. The effects of MAPK/ERK kinase （MEK）-inhibitor U0126 on CGRP-induced MCP-1 expression in primary rat osteoblasts were examined. Results CGRP effectively enhanced primary rat osteoblast proliferation and led to significant increases in the expression of MCP-1 mRNA and protein in time- and dose-dependent manners. CGRP activated the ERK pathway. Pretreatment of cultured rat osteoblasts with MEK inhibitor U0126 resulted in dose-dependent inhibitions of CGRP-induced MCP-1 mRNA and protein levels. Thus, CGRP promoted cell proliferation and stimulated MCP-1 expression in cultured rat osteoblasts. Conclusion These studies document novel links between CGRP and MCP-1 and illuminate the effects of CGRP in regulating bone remodeling.

Glucocorticoid modulation of extracellular signal-regulated protein kinase 1/2 and p38 in human ovarian cancer HO-8910 cells

Objective To investigate the signaling pathway through testing the effects of dexamethasone (Dex) on the activation of the extracellular signal-regulated protein kinase 1/2 (ERK1/2) and p38 kinase (p38) in HO-8910 cells.Methods Activation of the ERK1/2 and p38 was detected by Western blotting using the antibodies against the total ERK1/2 and p38 mitogen-activated protein kinases (MAPKs) protein and the phosphorylated forms of them. Results Dex could suppress the activation of ERK1/2, while enhance the activation of p38 rapidly and strongly in a dose- and time- dependent manner. Neither effect could be blocked by RU486, the antagonist of glucocorticoid receptor (GR).Conclusion Dex has rapid effects on the activation of ERK1/2 and p38, and these effects are not mediated by GR.

Hepatitis B virus X protein up-regulates tumor necrosis factor-α expression in cultured mesangial cells via ERKs and NF-κB pathways

Objective:To investigate the effects of hepatitis B virus(HBV)X protein(HBx)on the expression of tumor necrosis factor-α(TNF-α)in glomerular mesangial cells(GMCs)and the underlying intracellular signal pathways.Methods:The plasmid pCI-neo-X that carries the X gene of hepatitis B virus was transfected into cultured GMCs.HBx expression in the transfected GMCs was assessed by Western-blot.TNF-αprotein and mRNA were assessed by ELISA and semi-quantitative RT-PCR,respectively.Three kinase inhibitors-U0126,an inhibitor of extracellular signal-regulated kinases(ERKs);lactacvstin,an inhibitor of nuclear factor-κB(NF-κB);and SB203580,a selective inhibitor of p38 MAP kinase(p38 MAPK)were used to determine which intracellular signal pathways may underlie the action of HBx on TNF-αexpression in transfected GMCs.Results:A significant increase in HBx expression in pCI-neo-X transfected GMCs was detected at 36 h and 48 h,which was not affected by any of those kinase inhibitors mentioned above.A similar increase in the expression of both TNF-αprotein and mRNA was also observed at 36 h and 48 h,which was significantly decreased in the presence of U0126 or lactacytin,but not SB203580.Conclusions:HBx upregulates TNF-αexpression in cultured GMCs,possibly through ERKs and NF-κB pathway,but not p38 MAPK pathway.

Protein tyrosine phosphatase 1B regulates migration of ARPE-19 cells through EGFR/ERK signaling pathway

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 &#x003b1;-smooth muscle actin (&#x003b1;-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. &#x003b1;-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, &#x003b1;-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.

不同级别胶质瘤患者MEK、ERK、CHKα蛋白的阳性表达情况及临床意义

目的探讨不同级别胶质瘤患者胆碱激酶α(CHKα)、细胞外信号调节激酶(ERK)及丝裂原激活蛋白激酶(MEK)蛋白的阳性表达情况及临床意义。方法回顾性分析2019年1月至2022年12月长沙市第四医院神经外科收治的124例胶质瘤患者的临床资料。检测、统计不同级别胶质瘤患者MEK、ERK、CHKα蛋白的阳性表达情况。结果不同肿瘤最大径、年龄、WHO分级及预后胶质瘤患者MEK、ERE、CHKα蛋白的高、低表达情况比较,差异均有统计学意义(P<0.05)。Ⅰ、Ⅱ、Ⅲ、Ⅳ级胶质瘤患者MEK蛋白阳性表达率分别为9.62%、7.69%、94.08%和92.04%,ERK蛋白阳性表达率分别为9.57%、7.49%、94.52%和92.18%,CHKα蛋白阳性表达率分别为9.60%、7.53%、94.71%和92.23%,高、低级别胶质瘤患者MEK、ERK、CHKα蛋白阳性表达率比较,差异均有统计学意义(P<0.05)。随访结束后结果显示,124例患者中死亡52例,失访12例,获得随访112例,随访率为90.32%。结论不同级别胶质瘤患者MEK、ERK、CHKα蛋白的阳性表达情况有明显区别,并且与患者的疾病预后明显相关,对疾病的诊断和预后判断具有重要价值。

二甲双胍调节MEK/ERK通路及基质金属蛋白酶在恶性肿瘤中应用的研究进展

二甲双胍是目前治疗2型糖尿病的一线用药,其通过改善胰岛素抵抗、抑制肝脏糖异生等途径降低血糖。近年发现,二甲双胍还可通过促分裂原活化的蛋白激酶激酶/胞外信号调节激酶信号通路以及基质金属蛋白酶诱导细胞周期停滞、促进细胞凋亡、抑制细胞侵袭迁移,并可与各种抗肿瘤药物联用发挥协同作用以抑制肿瘤进展。但目前仍缺乏二甲双胍可以抑制癌症患者病情进展的研究证据,未来还需要对二甲双胍在恶性肿瘤治疗中的作用及其有效性、安全性进行进一步研究。

富含半胱氨酸和甘氨酸蛋白2在神经母细胞瘤恶性进展中的功能和机制

目的:探究富含半胱氨酸和甘氨酸蛋白2(cysteine and glycine-rich protein 2,CSRP2)在神经母细胞瘤(neuroblastoma,NB)恶性进展中的功能和作用机制。方法:利用R2数据库分析NB临床样本中CSRP2基因的mRNA水平与NB患儿临床预后的相关性;在NB细胞系SK-N-BE(2)和SH-SY5Y中利用靶向小干扰RNA(small interfering RNA,siRNA)干扰CSRP2的表达或利用质粒转染过表达CSRP2;通过结晶紫染色和实时无标记动态细胞分析技术观察NB细胞的增殖情况;采用克隆形成方法观察NB细胞长时间的克隆形成能力;利用免疫荧光实验检测细胞增殖标记物Ki-67的水平;利用碘化丙啶(propidium iodide,PI)染色流式细胞术分析细胞周期比例,Annexin V/7AAD染色分析细胞凋亡比例;采用划痕实验观察细胞的迁移能力;利用Western blot或实时荧光定量PCR(quantitative real-time PCR,RT-qPCR)检测NB原发肿瘤组织和细胞系中蛋白和基因的表达水平。结果:NB临床数据库中,国际神经母细胞瘤分期(international neuroblastoma staging system,INSS)为高危险度3/4期的NB组织中CSRP2的mRNA水平显著高于低危险度的1/2期,且高表达水平组NB患儿的生存期显著低于低表达组;Western blot结果显示,CSRP2在3/4期NB组织中的蛋白水平显著高于1/2期。NB细胞中敲低CSRP2,细胞的活力减弱、增殖能力降低;NB细胞中过表达CSRP2促进细胞增殖;敲低CSRP2后,sub-G1、G0/G1和S期细胞的比例增加,Annexin V阳性细胞的比例增多;敲低CSRP2的NB细胞的划痕愈合率显著小于对照组。机制研究发现,敲低CSRP2后细胞增殖标记分子Ki-67和细胞外信号调节激酶1/2(extracellular signal-regulated kinases 1/2,ERK1/2)磷酸化水平显著低于对照组。结论:CSRP2在高危险度3/4期NB组织中高表达,表达水平与NB患儿生存期呈负相关;CSRP2通过促进ERK1/2活化,促进NB细胞的增殖和迁移,抑制细胞凋亡,表明CSRP2通过激活ERK1/2促进NB进展,为高危NB的靶向治疗提供了潜在的靶点。

车叶草苷调节RAS/RAF/MEK/ERK信号通路对肝细胞癌细胞活性及裸鼠移植瘤生长的影响

目的探讨车叶草苷调节Ras蛋白(Ras protein,RAS)/Raf蛋白激酶(Raf protein kinase,RAF)/丝裂原激活蛋白激酶激酶(mitogen-activated protein kinase kinase,MEK)/细胞外信号调节激酶(extracellular signal-regulated kinase,ERK)信号通路对肝细胞癌(hepatocellular carcinoma,HCC)细胞活性及裸鼠移植瘤生长的影响。方法体外培养人HCC-LM3以细胞计数试剂盒(cell counting kit 8,CCK-8)法筛选车叶草苷体外最佳作用浓度。将HCC-LM3细胞随机分为对照组(细胞正常培养,不作其他干预)、车叶草苷组(3 mmol/L车叶草苷进行干预)、ML-098组(0.5μmol/L RAS激活剂ML-098进行干预)、车叶草苷+ML-098组(车叶草苷3 mmol/L和RAS激活剂ML-098终浓度0.5μmol/L联合干预)。以CCK-8法、流式细胞术分别检测各组HCC-LM3细胞活性、凋亡率;Western blot检测各组HCC-LM3细胞增殖、凋亡相关蛋白表达及RAS/RAF/MEK/ERK信号通路相关蛋白表达。制备HCC-LM3裸鼠原位癌模型并随机分为对照组(5 ml/kg生理盐水)、车叶草苷低剂量组(25 mg/ml车叶草苷)、车叶草苷中剂量组(50 mg/ml车叶草苷)、车叶草苷高剂量组(100 mg/ml车叶草苷)。检测各组裸鼠肝体比、肿瘤长径。以Ki67免疫组织化学染色法检测各组裸鼠肿瘤细胞增殖指数;Western blot检测各组裸鼠肿瘤RAS/RAF/MEK/ERK信号通路相关蛋白表达。结果与对照组相比,车叶草苷组HCC-LM3细胞凋亡率、裂解凋亡蛋白酶3(Cleaved caspase-3)与B细胞淋巴瘤2相关X蛋白(Bcl-2 associated X protein,Bax)、含半胱氨酸的天冬氨酸蛋白水解酶9(cysteinyl aspartate specific proteinase 9,caspase-9)蛋白表达均升高(P均<0.05),细胞活性、增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)与RAS蛋白表达、p-RAF/RAF、p-MEK/MEK、p-ERK/ERK均降低(P均<0.05);ML-098对HCC-LM3细胞各指标的作用与车叶草苷相反(P<0.05)。与车叶草苷组相比,车叶草苷+ML-098组HCC-LM3细胞凋亡率、Cleaved caspase-3与Bax、caspase-9蛋白表达均降低(P均<0.05),细胞活性、PCNA与RAS蛋白表达、p-RAF/RAF、p-MEK/MEK、p-ERK/ERK均升高(P均<0.05)。与对照组相比,车叶草苷低、中、高剂量组裸鼠肝体比、肿瘤长径、肿瘤细胞增殖指数、RAS蛋白表达、p-RAF/RAF、p-MEK/MEK、p-ERK/ERK均降低(P均<0.05),并呈一定剂量依赖性(P均<0.05)。结论车叶草苷可抑制RAS/RAF/MEK/ERK信号通路激活,降低HCC细胞体外细胞活性并促使其凋亡,延缓其裸鼠移植瘤生长。

异钩藤碱对大鼠急性胰腺炎细胞的炎症和凋亡改善及ERK信号通路调控作用

目的观察异钩藤碱(LSO)对大鼠急性胰腺炎(AP)细胞炎症和凋亡改善及ERK信号通路调控作用。方法将AR42J细胞分为6组,对照组正常培养,模型组、LSO组、抑制剂组、LSO+抑制剂组、LSO+激活剂组加入100 nmol/L雨蛙素制备AP细胞模型,LSO组制模后加入40μmol/L LSO,抑制剂组制模后加入10μmol/L U0126,LSO+抑制剂组制模后加入40μmol/L LSO和10μmol/L U0126,LSO+激活剂组制模后加入40μmol/L LSO和0.1μmol/L C16-PAF。采用ELISA法、EdU法及Hoechst 33258染色法分别测定细胞培养液中的炎症因子(TNF-α、IL-6、IL-8、IL-1β)、细胞增殖率和凋亡率,qPCR法测定细胞中NLRP3、斑点样蛋白(ASC)、半胱氨酸蛋白酶-1(Caspase-1)mRNA,WB法测定细胞中ERK 1/2、p-ERK 1/2、NLRP3、ASC、Caspase-1蛋白。结果与对照组比较,模型组细胞TNF-α、IL-6、IL-8、IL-1β、凋亡率、p-ERK 1/2蛋白及NLRP3、ASC、Caspase-1 mRNA和蛋白升高,增殖率降低(P均<0.05);与模型组比较,LSO组、抑制剂组细胞炎症因子(TNF-α、IL-6、IL-8、IL-1β)、凋亡率、p-ERK 1/2蛋白及NLRP3、ASC、Caspase-1 mRNA和蛋白降低,增殖率升高(P均<0.05);与LSO组比较,LSO+抑制剂组中U0126增强了LSO对细胞上述指标趋势的作用,而LSO+激活剂组中C16-PAF则逆转了LSO对细胞上述指标趋势的作用(P均<0.05)。结论LSO对大鼠急性胰腺炎细胞的炎症和凋亡有改善作用,可能通过调控ERK信号通路来实现。

基于EGFR/MAPK/ERK信号通路探讨鳖甲煎丸对MHCC-97H肝癌细胞皮下瘤的抑瘤作用

目的基于表皮生长因子受体(epidermal growth factior receptor,EGFR)/丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)/细胞外信号调节激酶(extracellular signal-regulated kinase,ERK)信号通路探究鳖甲煎丸对MHCC-97H肝癌细胞皮下瘤的抑瘤作用及作用机制。方法选取30只雄性BLAB/c裸鼠,建立MHCC-97H肝癌细胞皮下瘤模型。造模成功后随机分为模型组,鳖甲煎丸低、中、高剂量组(0.55、1.1、2.2 g/kg),西药组(乐伐替尼4 mg/kg+吉非替尼80 mg/kg),每组6只。鳖甲煎丸低、中、高剂量组灌胃2次/d,西药组每周灌胃5 d,模型组予以等量生理盐水2次/d灌胃,每组连续干预2周。观察大鼠一般情况;计算各组大鼠抑瘤率;HE染色观察病理形态学变化;RT-qPCR检测瘤体组织中EGFR、丝裂原活化蛋白质激酶激酶(mitogen-activated protein kinase kinase,MEK)、ERK1、ERK2 mRNA表达水平;Western blot检测EGFR、磷酸化的EGFR(p-EGFR)、MEK、磷酸化的MEK(p-MEK)、ERK1、ERK2、磷酸化的ERK1/2(p-ERK1/2)、基质金属蛋白酶-1(matrix metalloproteinase-1,MMP-1)、细胞周期蛋白D1(cell cycle protein D1,Cyclin D1)、神经型钙黏附蛋白(N-cadherin)、上皮型钙黏附蛋白(E-cadherin)相对表达水平。结果与模型组比较,鳖甲煎丸低、中、高剂量组及西药组精神、反应、进食饮水等情况均明显改善。与第0天比较,各组第14天体质量明显降低(P<0.01)。与模型组、鳖甲煎丸低剂量组比较,鳖甲煎丸中、高剂量组和西药组瘤体质量减轻(P<0.05,P<0.01)。鳖甲煎丸低、中、高剂量组和西药组抑瘤率分别为20%、47.73%、55.91%、75.45%。与模型组比较,鳖甲煎丸低、中、高剂量组及西药组肿瘤细胞排列疏松,边界模糊,细胞核固缩、破裂,其中西药组最明显。与模型组比较,鳖甲煎丸低、中、高剂量组和西药组EGFR、MEK、ERK1、ERK2 mRNA表达水平明显下降(P<0.01);与鳖甲煎丸低剂量组比较,鳖甲煎丸高剂量组和西药组EGFR、MEK、ERK1、ERK2 mRNA表达水平显著降低(P<0.01),鳖甲煎丸中剂量组ERK1 mRNA表达水平显著降低(P<0.01);与鳖甲煎丸中剂量组比较,西药组EGFR、ERK2 mRNA表达水平降低(P<0.05,P<0.01)。与模型组比较,鳖甲煎丸中、高剂量组和西药组p-EGFR/EGFR、p-MEK/MEK、p-ERK1/ERK1、p-ERK2/ERK2、MMP-1、Cyclin D1、N-cadherin蛋白相对表达水平下降(P<0.05,P<0.01),E-cadherin蛋白相对表达水平明显升高(P<0.01)。与鳖甲煎丸高剂量组比较,西药组p-EGFR/EGFR、p-ERK1/ERK1、MMP-1、Cyclin D1、N-cadherin蛋白相对表达水平明显下降(P<0.01),E-cadherin蛋白相对表达水平升高(P<0.05)。结论鳖甲煎丸可能通过抑制EGFR/MAPK/ERK信号通路激活,从而下调MMP-1、Cyclin D1、N-cadherin蛋白,上调E-cadherin蛋白表达,进而对MHCC-97H肝癌细胞皮下瘤产生显著的抑制作用。

澳洲茄碱对肺癌A549细胞生物活性、瘤体抑制及MAPK/ERK1/2的影响

目的澳洲茄碱对肺癌A549细胞生物活性、瘤体抑制及MAPK/ERK1/2信号的影响。方法将人肺癌细胞株A549分为空白组、低剂量澳洲茄碱组、中剂量澳洲茄碱组、高剂量澳洲茄碱组及顺铂组,分别加入浓度为0、15、20、25μmol/L的澳洲茄碱及2μg/mL顺铂培养。MTT检测活性;流式细胞仪检测凋亡率;Transwell法检测侵袭;划痕试验检测划痕愈合率。25只裸鼠分为空白组、低剂量澳洲茄碱组、中剂量澳洲茄碱组、高剂量澳洲茄碱组及顺铂组,皮下注射0.3 mL的0、15、20、25μmol/L的澳洲茄碱及2μg/mL顺铂共培养A549细胞,观察瘤体质量及抑瘤率。结果澳洲茄碱组降低A549细胞活性,凋亡率升高,侵袭、划痕愈合率、MAPK、p-MAPK、ERK1/2及p-ERK1/2蛋白水平降低(P<0.05)。结论澳洲茄碱可抑制肺癌细胞增殖、侵袭及转移,并加快凋亡,作用呈现剂量依赖性且高剂量效果最佳,研究机制可能与抑制MAPK/ERK1/2信号表达相关。

赤凤迎源针刺法对面神经损伤模型大鼠Ras/MEK/ERK信号通路的影响

目的探讨赤凤迎源针刺法对面神经超微结构、丝裂原活化的细胞外信号调节激酶(mitogen-activated extracellular signal-regulated kinase,MEK)、细胞外信号调节蛋白激酶(extracellular signal-regulated kinase,ERK)及血清KRas蛋白表达的影响。方法将SD大鼠随机分为空白对照组、模型组、常规针刺组、赤凤迎源针刺组,每组8只。除空白对照组大鼠正常饲养外,其他各组大鼠用面神经颊支压榨法诱导面神经损伤模型。造模成功后,予以干预2周。干预结束后,行电镜检查观察大鼠的面神经超微结构;通过HE染色观察面神经组织形态组织学变化;ELISA法检测血清KRas的表达水平;Western blot检测面神经组织MEK、ERK蛋白的表达水平。结果造模后,与空白对照组比较,另外3组大鼠动物行为学评分均明显升高(P<0.01)。针刺2周后,常规针刺组及赤凤迎源针刺组大鼠评分明显低于模型组(P<0.01),且赤凤迎源针刺组评分低于常规针刺组(P<0.01)。针刺2周后,与模型组对比,常规针刺组及赤凤迎源针刺组面神经轴突纤维排列较紧密,内质网较多,KRas蛋白表达明显升高(P<0.05),面神经MEK蛋白、ERK蛋白表达升高(P<0.05),且赤凤迎源针刺组均高于常规针刺组(P<0.05)。结论赤凤迎源针刺法可改善面神经损伤模型大鼠动物行为学,上调KRas、MEK及ERK表达水平,可能与激活Ras/MEK/ERK信号通路有关,从而修复面神经损伤。