p38 MAPK在喹乙醇诱导HepG2细胞凋亡中的作用

目的:研究p38 MAPK信号通路在喹乙醇诱导的HepG2细胞凋亡中的作用。方法:分别用不同浓度(0、200、400、800μg/ml)的喹乙醇染毒HepG2细胞24 h和800μg/ml喹乙醇染毒HepG2细胞不同时间(0、0.5、1、2、4、6、12、24 h)后,采用Westernblot法检测细胞内磷酸化p38蛋白和p38总蛋白的表达情况,以p38 MAPK磷酸化水平反映p38 MAPK信号通路的活性。分别采用0、10、20μmol/L的p38 MAPK特异性抑制剂SB203580预处理HepG2细胞1 h后,再用800μg/ml喹乙醇染毒24 h,采用Annexin VFITC/PI法检测细胞凋亡。结果:随着喹乙醇染毒浓度和时间的增加,HepG2细胞的p38磷酸化蛋白表达量逐步增加,其中800μg/ml喹乙醇染毒细胞24 h的实验组与对照组相比,p38磷酸化蛋白的表达量明显上调(P0.01)。10、20μmol/L的SB203580对喹乙醇诱导细胞凋亡有促进作用,细胞的凋亡率分别为35.4%±2.83%、40.2%±3.98%,较喹乙醇对照组(23.1%±3.59%)明显升高(P0.05)。结论:喹乙醇能激活p38 MAPK信号通路,且p38 MAPK信号通路的激活参与抑制喹乙醇介导的HepG2细胞凋亡的过程。     

缺氧对人肝癌HepG2细胞凋亡及p38MAPK通路的影响

目的:探讨缺氧对人肝癌HepG2细胞凋亡及p38MAPK通路的影响。方法:用三气培养箱培养肝癌细胞HepG2,建立缺氧细胞模型,CCK-8 法检测HepG2细胞的增殖率,流式细胞术检测细胞凋亡率,Real-time PCR分析p38MAPK mＲNA的表达,Western blot法检测p38MAPK及p-p38MAPK蛋白的表达变化。结果:缺氧可抑制人肝癌HepG2细胞的增殖,抑制细胞凋亡（P<0.05）;缺氧处理人肝癌HepG2细胞后,p38MAPK mＲNA的表达量下调(P<0.05);Western blot结果显示缺氧可下调p38MAPK、p-p38MAPK蛋白的表达（P<0.05）。结论:缺氧通过抑制p38MAPK通路抑制人肝癌HepG2细胞凋亡。     

幽门螺杆菌对人胃癌MKN45细胞p38MAPK信号转导通路激活作用的研究

背景与目的: 环氧合酶2(cyelooxygenase-2,COX-2)是花生四烯酸转化为前列腺素(prostaglandins,PGs)代谢中重要的限速酶,幽门螺杆菌(Helicobacterpylori,Hp)感染诱导胃黏膜COX-2的过度表达是胃癌发生的重要环节,但Hp感染胃黏膜细胞COX-2表达的机制尚不清楚.本研究旨在揭示Hp对人胃癌MKN45细胞COX-2表达和p38MAPK信号通路的影响,探讨COX-2表达的可能机制.方法: 采用实时荧光定量PCR(real time-PCR)检测Hp标准株NCTC11637感染对人胃痛MKN45细胞COX-2 mRNA转录的影响,Western blot检测坳COX-2蛋白表达的影响和p38MAPK信号通路的激活及其下游因子ATF-2的表达.结果: Hp感染人胃癌MKN45细胞后,COX-2 mRNA的表达明显上调,Hp感染3、6、9、12 h后COX-2 mRNA的表达量分别为正常值的3倍、7.2倍、5.1倍和4.3倍,各时间组COX-2 mRNA表达均明显高于对照组(P＜0.01);Up与MKN45细胞共培养24 h后,COX-2蛋白的表达亦显著增加(P＜0.01).Hp感染MKN45 20 min后,p38MAPK信号通路被激活,60 min达峰值;p38MAPK下游因子ATF-2的表达也明显增加,2 h达高峰,随着作用时间的延长,表达逐渐下降,24 h仍有表达.结论: Hp感染能诱导人胃癌MKN45细胞COX-2的表达;激活p38MAPK信号通路,增加其下游因子ATF-2的表达,可能是其诱导COX-2表达的机制.     

Helicobacter pylori enhances cyclooxygenase 2 expression via p38MAPK/ATF-2 signaling pathway in MKN45 cells

The over-expression of COX-2 (Cyclooxygenase 2) protein has been reported to play a key role in the incidence and development of Helicobacter pylori-associated gastric cancer. The induction of COX-2 in the gastric cancer cells with H. pylori has been demonstrated previously, but little is known about the mechanism. This study reported that the COX-2 mRNA and proteins expression level and the activity of COX-2 promoter increased remarkably with H. pylori stimulation in the MKN45 gastric cancer cells. H. pylori also stimulated phosphorylation of p38MAPK and ATF-2, which is the downstream kinase of p38MAPK. Moreover, the expression levels of COX-2 were suppressed with p38MAPK inhibitor treatment. These results suggest that H. pylori-induced activation of p38MAPK/ATF-2-mediated signal pathway is necessary for the expression of COX-2.     

过表达PRRX1 通过p53 介导的线粒体凋亡途径诱导肝癌SMMC7721 细胞凋亡

[摘要] 目的：探讨配对相关同源框1 蛋白（PRRX1）过表达对肝癌SMMC7721 细胞凋亡的影响及其分子机制。方法：分别用慢病毒介导PRRX1 过表达载体（pGMLV-PRRX1）、空载质粒（Vector）感染人肝癌SMMC7721 细胞,用qPCR和WB实验检测慢病毒感染后细胞中PRRX1 mRNA和蛋白的表达变化,用CCK-8 法、Annexin-V FITC/PI 染色流式细胞术分别检测PRRX1 过表达对SMMC7721 细胞增殖、凋亡的影响,用线粒体膜电位检测试剂盒（JC-10 染色法）检测细胞线粒体膜电位变化,用caspase 活性检测试剂盒（分光光度法）测定细胞中caspase-8 和caspase-9 酶活性,用WB实验检测细胞中p53、Bcl-2、Bax、Fas、Cleaved-caspase-3以及线粒体和细胞质中细胞色素C（Cty C）蛋白的表达。结果：成功构建PRRX1 过表达的SMMC7721 细胞株,感染细胞中PRRX1 mRNA和蛋白的表达水平显著升高（均P<0.01）。与对照组和空载组比较,PRRX1 过表达组SMMC7721 细胞的增殖能力显著下降、细胞凋亡率显著增高、Cleaved-caspase-3 剪切水平显著升高、线粒体膜电位显著下降、线粒体中Cty C蛋白表达下调、胞质中Cty C蛋白表达上调以及caspase-9 酶活性升高（P<0.05 或P<0.01）,同时p53 和Bax 蛋白表达增加而Bcl-2 蛋白表达降低（均P<0.05）,但Fas 蛋白表达及caspase-8 酶活性无显著变化（均P>0.05）。结论: PRRX1 过表达可诱导肝癌SMMC7721 细胞凋亡,其机制可能与p53介导的线粒体凋亡途径被激活有关。     

PTPN6通过抑制SP1/p38 MAPK信号通路促进前列腺癌细胞的化疗敏感性

目的:研究PTPN6对前列腺癌细胞PC3的作用及其作用机制。方法:RT-PCR和Western blot实验检测前列腺癌组织和细胞以及癌旁组织和人前列腺上皮细胞中PTPN6的表达量;CCK-8和EDU染色实验检测PTPN6对前列腺癌细胞PC3增殖的影响;Western blot实验检测耐药相关蛋白P-gp和MRP-1的蛋白表达水平。结果:RT-PCR和Western blot结果显示,PTPN6在前列腺癌组织和细胞中的表达量显著低于癌旁组织和人前列腺上皮细胞中的表达量;过表达PTPN6显著抑制前列腺癌PC3细胞的增殖,并降低PC3细胞的耐药性;进一步的研究结果表明PTPN6可通过抑制SP1,并抑制p38 MAPK通路抑制PC3细胞的增殖和耐药。结论:PTPN6能够抑制前列腺癌细胞PC3的增殖和耐药,提高其化疗敏感性,作用机制是通过调控SP1/p38 MAPK信号通路来实现的,这一结果能够为临床上前列腺癌的诊断和治疗提供分子基础。     

p38MAPK 在结肠癌细胞凋亡中的作用及与COX-2 的关系

 目的 探讨结肠癌细胞p38MAPK介导celecoxib（COX-2选择性抑制剂）抗肿瘤的作用及与COX-2的关系。方法 用MTT法检测celecoxib对人结肠癌HT-29细胞生长的作用，用Western blot法测定各组细胞COX-2和Phosph—p38MAPK蛋白表达量，采用流式细胞术检测celecoxib和SB203580（p38MAPK特异性抑制剂）作用后HT-29细胞凋亡和细胞周期分布。结果 p38MAPK和COX-2蛋白表达量与对照组（0．23±0.12）（0.95±0．14）相比，celecoxib可使p38MAPK蛋白表达水平明显升高（0．62±0．11），而使COX-2蛋白表达水平降低（0、44±0．11）；SB203580使p38MAPK（0.12±0．05）及COX-2蛋白（0、23±0．13）表达水平均降低；SB203580和celecoxib共同作用后，p38MAPK表达量介于celecoxib和SB203580作用之间（0．43±0．12），COX-2表达量下降最为显著（0．15±0．10））。celecoxib和eeleeoxib＋SB203580均可显著诱导HT-29细胞凋亡（P〈0．01和P〈0．05），与对照纽（4．31％）相比，其凋亡率分别为40．95％、26．24％。结论 在HT29细胞中，celecoxib可通过活化p38MAPK而诱导结肠癌细胞凋亡，p38MAPK是COX-2的上游激酶，COX-2的表达水平受p38MAPK调控，并且COX-2可能对p38MAPK有负反馈调节作用。celecoxib是通过COX-2及其以外的p38MAPK通路诱导肿瘤细胞凋亡而发挥抗肿瘤作用的。     

BMP-2对人卵巢浆液性囊腺癌HO8910细胞凋亡的影响及机制研究

目的:研究BMP-2对人卵巢浆液性囊腺癌HO8910细胞的影响及其机制.方法:MTT、流式细胞仪技术、Annexin V/PI双染、Hoechst33258染色观察BMP-2对HO8910细胞凋亡的影响,并检测BMP-2作用后HO8910细胞中p21、caspase-3的变化.结果:BMP-2作用后HO8910细胞生长被抑制,凋亡增加,且p21、caspase3的表达较前增强.结论:BMP-2促进HO8910卵巢癌细胞凋亡,抑制其生长.     

乙型肝炎病毒X蛋白对肝癌细胞MKK3,p38MAPK表达的影响

目的：观察乙型肝炎病毒X蛋白对肝癌细胞中丝裂原活化蛋白激酶（MKK3）及其下游分子p38丝裂酶原活化的蛋白激酶（p38MAPK）的表达的影响,探讨相关的信号转导机制,及其对肝癌细胞生物学行为的影响。方法：分别将质粒pCDNA3.1及pCDNA3.1-HBx重组质粒经脂质体介导转染人肝癌细胞株HepG2,G418筛选培养,并用反转录PCR和Western blot鉴定,获得表达X蛋白的稳定细胞株HepG2-HBx和阴性对照细胞株HepG2-pCDNA3.1,以HepG2细胞株作空白对照。通过RT-PCR和Western blot检测上述三种细胞株中MKK3,p38MAPK在mRNA水平和蛋白水平的表达变化,并用细胞免疫荧光法检查磷酸化p38MAPK蛋白在细胞浆及细胞核中的变化;通过MTT实验检测三种细胞株的增殖情况。采用SPSS 12软件进行统计学分析。结果：MKK3在mRNA和总蛋白水平的表达在HepG2-HBx中均高于其他两组,其他两组无明显差异;p38MAPK在mRNA和总蛋白水平三组无明显差异,而其蛋白磷酸化水平和在核蛋白中的表达在HepG2-HBx中较其他两组升高;HepG2-HBx较其他两组细胞有更强的增殖能力。结论：HBx可以通过上调肝癌细胞中MKK3的表达,促进p38MAPK磷酸化和入核,从而进一步激活下游分子发挥生物活性。p38MAPK通路在HBx促进肝癌细胞的增殖中发挥重要作用。可能是导致HBV相关性肝癌与非HBV相关性肝癌临床特点及肿瘤生物学差异的机制之一。     

氯喹通过激活P38MAPK通路诱导人肝癌HepG2细胞凋亡

目的：研究氯喹对人肝癌HepG2细胞增殖和凋亡的影响,并初步研究其可能的机制。方法：体外培养HepG2细胞,采用MTT法检测不同浓度（0、10、20和40 μmol/L）氯喹作用不同时间（24、48和72 h）后对细胞增殖的影响;用DAPI染色观察氯喹处理细胞24 h后细胞核的变化;流式细胞术检测氯喹对HepG2细胞凋亡的影响;Western blot技术检测氯喹对HepG2细胞中Caspase-3、Bcl-2、Bax、P-P53、P38MAPK和P-P38MAPK蛋白表达的影响。结果：与对照组比较,在上述3个时间点10、20、40 μmol/L氯喹（10 μmol/L氯喹作用24 h组除外）对人肝癌HepG2细胞的增殖均有明显抑制作用（P均 < 0.05）;荧光显微镜下发现,10、20、40 μmol/L氯喹处理24 h后均可引起HepG2细胞不同程度的核浓集、固缩等典型凋亡形态变化;流式细胞术结果提示10、20、40 μmol/L氯喹能诱导HepG2细胞凋亡（P均 < 0.05）;Western blot结果显示20和40 μmol/L氯喹作用HepG2细胞后,P-P53、P-P38MAPK、剪切后活化型Caspase-3和Bax蛋白表达量增加（P均 < 0.05）,Bcl-2表达下降,Caspase-3和P38MAPK表达无明显变化（P > 0.05）。结论：氯喹能够抑制人肝癌HepG2细胞的生长并诱导其凋亡,其机制可能与P38MAPK通路有关。     

Overexpression of the <Emphasis Type="Italic">wip1</Emphasis> gene abrogates the p38 MAPK/p53/Wip1 pathway and silences p16 expression in human breast cancers

Wild-type p53-induced phosphatase (Wip1 or PPM1D) is a serine/threonine protein phosphatase expressed under various stress conditions, which selectively inactivates p38 MAPK. The finding that this gene is amplified in association with frequent gain of 17q21–24 in breast cancers supports its role as a driver oncogene. However, the pathogenetic mechanism of the wip1 gene expression in breast carcinogenesis remains to be elucidated. In this study, we examine Wip1 mRNA and protein expression in 20 breast cancer tissues and six cell lines. We additionally investigate the relationship among Wip1, active p38 MAPK, p53, and p16 proteins. In our experiments, Wip1 mRNA was significantly upregulated in 7 of 20 (35%) invasive breast cancer samples. Overexpression of Wip1 was inversely correlated with that of active (phosphor-) p38 MAPK (P = 0.007). Furthermore, Wip1-overexpressing tumors exhibited no or low levels of p16, which normally accumulates upon p38 MAPK activation (P = 0.057). Loss of p16 expression was not associated with hypermethylation of its promoter or loss of heterozygosity on 9p21. Among the 135 primary breast carcinomas further examined, a significant association was found between the Wip1 overexpression and negative staining for p53 (P value = 0.057), indicating that the tumors are wild-type for p53. This is first report showing that Wip1 overexpression abrogates the homeostatic balance maintained through the p38–p53-Wip1 pathway, and contributes to malignant progression by inactivating wild-type p53 and p38 MAPK as well as decreasing p16 protein levels in human breast tissues. Eunsil Yu and Yeon Sun Ahn contributed equally to this work     

乙型肝炎病毒X蛋白对肝癌细胞MKK3,p38MAPK表达的影响

目的:观察乙型肝炎病毒X蛋白对肝癌细胞中丝裂原活化蛋白激酶(MKK3)及其下游分子p38丝裂酶原活化的蛋白激酶(p38MAPK)的表达的影响,探讨相关的信号转导机制,及其对肝癌细胞生物学行为的影响。方法:分别将质粒pCDNA3.1及pCDNA3.1-HBx重组质粒经脂质体介导转染人肝癌细胞株HepG2,G418筛选培养,并用反转录PCR和Western blot鉴定,获得表达X蛋白的稳定细胞株HepG2-HBx和阴性对照细胞株HepG2-pCDNA3.1,以HepG2细胞株作空白对照。通过RT-PCR和Western blot检测上述三种细胞株中MKK3,p38MAPK在mRNA水平和蛋白水平的表达变化,并用细胞免疫荧光法检查磷酸化p38MAPK蛋白在细胞浆及细胞核中的变化;通过MTT实验检测三种细胞株的增殖情况。采用SPSS 12软件进行统计学分析。结果:MKK3在mRNA和总蛋白水平的表达在HepG2-HBx中均高于其他两组,其他两组无明显差异;p38MAPK在mRNA和总蛋白水平三组无明显差异,而其蛋白磷酸化水平和在核蛋白中的表达在HepG2-HBx中较其他两组升高;HepG2-HBx较其他两组细胞有更强的增殖能力。结论:HBx可以通过上调肝癌细胞中MKK3的表达,促进p38MAPK磷酸化和入核,从而进一步激活下游分子发挥生物活性。p38MAPK通路在HBx促进肝癌细胞的增殖中发挥重要作用。可能是导致HBV相关性肝癌与非HBV相关性肝癌临床特点及肿瘤生物学差异的机制之一。     

Hibiscus polyphenol-rich extract induces apoptosis in human gastric carcinoma cells via p53 phosphorylation and p38 MAPK/FasL cascade pathway

In view of the continuing need for effective anticancer agents, and the association of diet with reduced cancer risk, edible plants are increasingly being considered as sources of anticancer drugs. Hibiscus sabdariffa Linne (Malvaceae), an attractive plant believed to be native to Africa, is cultivated in the Sudan and Eastern Taiwan. Polyphenols had been demonstrated previously to possess antioxidative and antitumor promoting effects. In this study, investigations were conducted to examine the mechanism of the anticancer activity of H. sabdariffa L., Hibiscus polyphenol-rich extracts (HPE). Using HPLC assay, HPE was demonstrated to contain various polyphenols. HPE induced cell death of eight kinds of cell lines in a concentration-dependent manner. Among them human gastric carcinoma (AGS) cells were the most susceptible to HPE (0.95 mg/mL HPE inhibited its growth by 50%). Our results revealed that AGS cells underwent DNA fragmentation, and had an increase in the distribution of hypodiploid phase (apoptotic peak, 52.36%) after a 24-h treatment with HPE (2.0 mg/mL). This effect of HPE in AGS cells might be mediated via p53 signaling and p38 MAPK/FasL cascade pathway, as demonstrated by an increase in the phosphorylation of p53 and the usage of a specific p38 inhibitor, SB203580. Thus, our data present the first evidence of HPE as an apoptosis inducer in AGS cells and these findings may open interesting perspectives to the strategy in human gastric cancer treatment.     

滋肾固髓汤通过调控p38MAPK/p53信号通路诱导结直肠癌HCT-116细胞凋亡

目的:探讨滋肾固髓汤对结直肠癌HCT-116细胞凋亡的影响及其分子机制。方法:制备滋肾固髓汤含药血清,首先采用不同体积分数滋肾固髓汤含药血清处理HCT-116细胞,噻唑蓝(MTT)检测细胞增殖活性;再将HCT-116细胞分为空白组、滋肾固髓汤低、中、高剂量组、SB203580(p38MAPK抑制剂)组和高剂量滋肾固髓汤+SB203580组,分别加入相应药物进行干预后,Hoechst 33258染色观察细胞凋亡的形态学变化;Annexin V-FITC流式细胞术检测细胞的凋亡水平;Western blot检测细胞中p38MAPK、磷酸化(p)-p38MAPK(Thr180/Tyr182)、鼠双微染色体2(MDM2)、p53、Cleaved caspase-3、Bax和Bcl-2等蛋白表达水平。结果:滋肾固髓汤可抑制HCT-116细胞增殖活性,并呈时间和浓度依赖性。不同浓度滋肾固髓汤处理可诱导HCT-116细胞呈现核聚集、皱缩或碎裂等凋亡形态变化,促进细胞凋亡,上调p-p38MAPK、p53、Bax和Cleaved caspase-3等蛋白表达水平,下调MDM2和Bcl-2蛋白表达水平。S...     

miR-125b prevent the progression of esophageal squamous cell carcinoma through the p38-MAPK signaling pathway

BackgroundTo examine the clinical significance of miR-125b in esophageal squamous cell carcinoma (ESCC) and to research the effect of miR-125b on the biological function of ESCC cells and the relevant underlying mechanism.MethodsThe expression of miR-125b in ESCC tissues and cell lines were discovered by RT-PCR assay. The interrelation between miR-125b expression and clinicopathological parameters and the forecasting of ESCC patients were analyzed. CCK-8 method and Transwell methods were used to detect the increased growth, shifting, and irruption of ESCC cells. Bioinformatics analysis was applied to forecast the possible target genes of miR-125b and verified through dual-luciferase reporter gene assay. After that, the expression of p38-MAPK mRNA and protein were found out by RT-PCR and Western blot.ResultsThe expression of miR-125b was down-regulated in ESCC tissues and cell lines (P<0.05). And the expression of miR-125b was closely about tumor differentiation, TNM level, and lymph node metastasis in ESCC patients. The low miR-125b formulation was closely related to rough forecasting in ESCC patients. Large scale expression of miR-125b can effectively decrease the acceleration, shifting, and irrupting strengths of ESCC cells. Bioinformatics analysis showed p38-MAPK was forecasted to be a potential mark of miR-125b, which was confirmed by dual luciferase assay, and extreme expression of miR-125b can stop the expression of p38-MAPK mRNA and protein.ConclusionsmiR-125b is down-regulated in ESCC. Moreover, its expression level is significant concerning tumor progression and prognosis in patients with ESCC. MiR-125b can stop the high growth and shifting of ESCC cells having p38-MAPK at target.     

p38MAPK基因对人胶质瘤细胞BT325生长周期的影响

目的　研究 p3 8MAPK基因对人多形性胶质母细胞瘤BT3 2 5生长周期的影响。 方法　利用脂质体介导法将p3 8MAPK基因导入BT3 2 5细胞中 ,用免疫细胞化学染色和Western blot检测其在转染前后的表达情况 ,用HE染色、透射电镜和流式细胞仪等研究其对细胞形态和生长周期的影响。结果　pCMV 5 p3 8MAPK组p3 8MAPK蛋白表达阳性 ,细胞形态发生变化 ,G1%增多 ,而S %和G2 %减少 ,并出现凋亡峰。结论　p3 8MAPK基因可影响BT3 2 5细胞的生长周期 ,并诱导BT3 2 5细胞凋亡。     

Apoptotic effect of 3,4-dihydroxybenzoic acid on human gastric carcinoma cells involving JNK/p38 MAPK signaling activation

3,4-Dihydroxybenzoic acid (protocatechuic acid, PCA) is discussed to represent antioxidative food components in a human diet rich in fruits and vegetables, and has been shown to prevent carcinogenesis or antitumor growth in vivo. However, the molecular mechanisms involved in chemopreventive activity of PCA are poorly understood. In this study, investigations were conducted to examine the detailed signaling pathway involved in PCA-induced apoptosis in human gastric adenocarcinoma (AGS) cells. The data from cell viability assay showed that PCA exhibited the antiproliferation effect on AGS cells in a time- and dose-dependent manner. The occurrence of apoptosis induced by PCA was confirmed by morphological and biochemical features, including apoptotic bodies formation and an increase in the distribution of hypodiploid phase. Molecular data showed the effect of PCA in AGS cells might be mediated via sustained phosphorylation and activation of JNK and p38 mitogen-activating protein kinases (MAPK), but not ERK. Treatment with pharmacological inhibitors or transfection with the mutant p38 or/and JNK expression vector reduced PCA-mediated apoptosis and the JNK/p38 MAPK-related proteins phosphorylation and expression, including ATF-2, c-Jun, FasL, Fas, p53 and Bax. Preincubation with Nok-1 monoclonal antibody, which is inhibitory to Fas signaling, interfered with PCA-induced cleavage of procaspase and sensitization to anti-APO-induced apoptosis. These results suggest the possible involvement of multiple signaling pathways from the MAPK to the subsequent mitochondria- and/or Fas-mediated caspase activation are potential requirements for PCA-induced AGS apoptosis. Further, PCA effectively induced JNK/p38 activation in PCA-response cell lines. Taken together, our data present the first evidence of PCA as an apoptosis inducer in AGS cells, even in tumor cells of digestive organs, and provide a new mechanism for its anticancer activity.