PTEN/PI3K/Akt信号通路对K562细胞凋亡调控的研究

 目的 探讨PTEN/PI3K/Akt信号传导通路对人慢性粒细胞白血病细胞系K562的增殖、凋亡调控的研究及可能的分子作用机制。 方法 将携带有野生型PTEN及绿色荧光蛋白的腺病毒（Ad-PTEN-GFP）及空载体（Ad-GFP）腺病毒,转染人慢性粒细胞白血病细胞系K562。通过MTT检测细胞生长曲线,流式细胞术检测细胞凋亡率和细胞增殖指数,同时用细胞光镜、电镜形态等方法检测细胞凋亡,荧光定量PCR（FQ-PCR）检测PTEN及凋亡相关基因Bcl-2、Bcl-_xL、Bax mRNA水平变化,Western blot检测PTEN及Akt、p-Akt蛋白水平变化。 结果 与Ad-GFP组相比,Ad-PTEN-GFP 转染K562细胞后,细胞增殖受抑,增殖指数降低,凋亡率增加,p-Akt表达降低,抗凋亡相关基因Bcl-2、Bcl-_xL mRNA表达降低,促凋亡基因Bax mRNA表达增加。 结论 过表达PTEN可能通过抑制PI3K/Akt通路抑制K562细胞系增殖,促进细胞凋亡。     

过表达miR-141-3p通过靶向下调PTEN并激活PI3K/Akt信号通路促进卵巢癌A2780 细胞的恶性生物学行为

[摘要] 目的：探讨miR-141-3p 通过靶向PTEN并调控PI3K/Akt 通路对卵巢癌细胞增殖、侵袭和凋亡的影响。方法：收集2014 年4 月至2017 年10 月河南省人民医院妇产科收治的资料完整的28 例卵巢癌患者肿瘤组织和相应的癌旁组织,采用qPCR检测卵巢癌组织和细胞系中miR-141-3p 的表达水平,双荧光素酶报告基因实验验证miR-141-3p 和PTEN的靶向关系;过表达或敲降miR-141 及PTEN基因后,采用CCK-8、Transwell 和Annexin V-FITC/PI 双染流式术检测卵巢癌A2780 细胞增殖、侵袭和凋亡水平,WB实验进一步检测miR-141-3p 对PTEN-PI3K/Akt 信号通路的调控作用。结果：miR-141-3p 在卵巢癌组织和细胞系中高表达（P<0.05 或P<0.01）。双荧光素酶报告基因证实miR-141-3p 靶向作用于PTEN并下调其表达水平（P<0.01）。与对照组相比,敲降miR-141-3p 后A2780 细胞的增殖受到显著抑制（48 h 时,0.36±0.04 vs 0.82±0.06,P<0.05）、侵袭能力明显降低[穿膜细胞数（45.14±7.88）vs（215.32±16.04）个,P<0.01]、细胞凋亡率显著升高[ （9.29±0.65）% vs（1.85±0.26）%,P<0.01]。过表达PTEN显著抑制了A2780 细胞中p-Akt 的表达（均P<0.01）、抑制细胞增殖和侵袭能力（均P<0.01）而明显促进细胞凋亡（均P<0.01）,在过表达PTEN的同时过表达miR-141-3p 或添加IGF-1 后可逆转上述的变化。结论：miR-141-3p 能够促进A2780 细胞增殖、侵袭和诱导凋亡,其机制可能与靶向调控PTEN并激活PI3K/Akt通路有关。     

PI3K/Akt信号通路在肿瘤化疗耐药中的作用

磷脂酰肌醇3-激酶-蛋白激酶B(PI3K/Akt)信号通路在细胞内发挥重要的作用,参与了许多生理和病理活动.目前研究发现在许多肿瘤中过度激活的PI3K/Akt信号通路与肿瘤化疗耐药的产生密切相关,体外研究显示采用PI3K/Akt信号通路抑制剂可以逆转肿瘤细胞的耐药.本文简要介绍了PI3K/Akt信号通路的基本组成结构,并重点介绍其在肿瘤化疗耐药中的作用.     

miR-186通过Shp2和PI3K/Akt/mTOR信号通路对肺腺癌细胞的抑制作用

目的 探讨miR-186过表达对肺腺癌细胞生长的影响及其是否与调节Shp2和PI3K/Akt/mTOR信号通路有关.方法 将人肺腺癌细胞A549分为Con-mimic组、miR-186-mimic组和Con组,采用CCK8细胞增殖实验检测miR-186对细胞增殖的影响;采用划痕实验检测miR-186对细胞转移的影响;采...     

大鼠乳腺癌骨转移模型中PI3K/Akt信号通路参与诱导疼痛

目的 探讨骨癌痛大鼠模型中PI3K/Akt信号通路参与痛觉过敏的产生和维持及其脊髓机制.方法 Wistar大鼠,体重在180~200 g,将大鼠随机分为3组:癌痛模型组(A组)、假手术组(B组)、正常组(C组),A组大鼠左侧胫骨髓腔内单次注入Walker256乳腺癌细胞建立大鼠胫骨癌痛模型,B组大鼠左侧胫骨注入等量生理盐水,C组做不给药处理.A组造模后第7天,评估筛选成模的大鼠,随机分为3组:癌痛组(A1组)、癌痛+NS组(A2组)、癌痛+抑制剂组(A3组).正常对照组(C组)随机分为2组:空白对照组(C1组)、空白+抑制剂组(C2).A3组和C2组分别在第13、14、21天鞘内注射Akt抑制剂GSK690693,A2组在第13、14、21天鞘内注射等量生理盐水,A1组、B组、C1组均不给药处理.在第0、7、14、21天,分别检测大鼠机械性缩足阈值(mechanical withdrawal threshold,MWT)和热缩腿潜伏期(thermal withdrawal latency,MWT).第21天行为学测试后处死大鼠,取大鼠脊髓L4~L6区段,用免疫组化及Western blot检测大鼠脊髓的磷酸化Akt(p-Akt)水平.结果 实验观察到大鼠的MWT和TWL均显著降低,第7天及14天A1组、A2组、A3组及B组分别与C1组比较,P<0.05,第21天A3组与A1组、A2组分别比较,P<0.05.与C1组比较,骨癌痛模型组大鼠脊髓背角p-Akt表达增强,鞘内注射Akt抑制剂可降低脊髓背角p-Akt的表达.结论 PI3K/Akt信号通路参与了骨癌痛的中枢敏化,在大鼠骨癌痛发生发展过程中起着重要作用.     

VES对MDA-MB-453细胞PI3K/Akt信号通路的影响

目的：检测维生素E琥珀酸酯（vitamin E succinate,VES）对MDA-MB-453乳腺癌细胞PI3K/Akt信号通路中PI3K及Akt表达的影响。方法：不同浓度VES作用于人乳腺癌细胞MDA-MB-453（Her-2过表达株）24h和48h,VES的浓度分别为5、10和20μg/ml。RT-PCR法检测VES作用前后PI3K及Akt的mR-NA表达变化。结果：VES对MDA-MB-453乳腺癌细胞PI3 K/Akt信号通路中PI3 K有抑制作用（P〈0.05）,并呈时间-剂量依赖关系;而对Akt无明显的抑制作用（P〉0.05）。结论：VES可能是通过作用于PI3K/Akt信号通路而发挥其对MDA-MB-453乳腺癌细胞的抑制及凋亡作用。     

PI3K/Akt/mTOR信号转导通路与非小细胞肺癌

肺癌是目前世界上发病率和死亡率最高的恶性肿瘤之一,其中非小细胞肺癌(non-small cell lung cancer,NSCLC)占肺癌的75%-85%,确诊时多属中晚期,常规放、化疗效果欠佳,5年生存率仅为5%-10%.PI3K/Akt/mTOR信号通路作为细胞内重要信号转导通路之一,通过影响下游多种效应分子的活化状态,与NSCLC的发生发展密切相关.本文综述了PI3K/Akt/mTOR信号通路的组成,其抑制凋亡、促进增殖的关键作用以及在NSCLC中的研究现状,以期为NSCLC的治疗寻找潜在的靶点.     

miR-143-3p靶向KRAS阻滞PI3K/Akt信号通路抑制分化型甲状腺癌细胞增殖、侵袭和迁移

目的:探讨miR-143-3p对分化型甲状腺癌细胞增殖、侵袭和迁移的影响及其作用机制.方法:采用qRT-PCR检测miR-143-3p在30例分化型甲状腺癌组织和对应的癌旁组织,以及人分化型甲状腺癌细胞(TCP-1、FTC-133、SW579、BCPAP)和甲状腺滤泡上皮正常细胞(Nthy-ori3-1)中的表达水平....     

PI3K/Akt/mTOR信号通路抑制剂在乳腺癌中的研究进展

目的:总结PI3K/Akt/mTOR信号通路靶向治疗在乳腺癌中的研究进展.方法:以“PI3K/Akt/mTOR、信号通路和乳腺癌”等为关键词,检索2000-01-2011-06 PubMed、Ovid和Springer等数据库的相关文献.纳入标准:1)关于PI3K/Akt/mTOR信号通路的组成、功能特点;2)PI3K/Akt/mTOR信号通路与乳腺癌的关系研究;3)以PI3K/Akt/mTOR信号通路中关键分子为靶点的乳腺癌治疗.根据纳入标准,符合分析的文献40篇.结果:信号转导通路的异常是肿瘤发生、发展的重要步骤,PI3K/Akt/mTOR信号通路与人类多种肿瘤密切相关,其在肿瘤细胞的增殖、存活、抵抗凋亡、血管发生和转移以及对放化疗抵抗中发挥了重要作用.乳腺癌中常见PI3K/Akt/mTOR信号通路的异常激活,以此通路为靶点的药物已成为乳腺癌治疗的研究热点.结论:靶向PI3K/Akt/mTOR通路中关键分子的众多药物在乳腺癌开展了一系列相关的临床试验研究,一部分显示出较好的安全性和有效性.随着对PI3K/Akt/mTOR通路的分子生物学机制的深入研究,期待靶向此通路的抑制剂将会在乳腺癌治疗中发挥巨大的作用,进一步提高乳腺癌患者的疗效和改善预后.     

PI3K—Akt信号通路与胃癌的研究进展

细胞内信号传导通路PI3K—Akt与胃癌的发生、生长及化疗耐药关系密切。本文概述了PI3K—Akt的分类结构、PI3K—Akt信号转导通路的调节、与胃癌细胞凋亡及血管生成的关系及化疗耐药和放疗的机制。     

Reduced PTEN expression in breast cancer cells confers susceptibility to inhibitors of the PI3 kinase/Akt pathway.

The PTEN protein is a lipid phosphatase with putative tumor suppressing abilities, including inhibition of the PI3K/Akt signaling pathway. Inactivating mutations or deletions of the PTEN gene, which result in hyper-activation of the PI3K/Akt signaling pathway, are increasingly being reported in human malignancies, including breast cancer, and have been related to features of poor prognosis and resistance to chemotherapy and hormone therapy. Prior studies in different tumor models have shown that, under conditions of PTEN deficiency, the PI3K/Akt signaling pathway becomes a fundamental proliferative and survival pathway, and that pharmacological inhibition of this pathway results in tumor growth inhibition. This study aimed to explore further this hypothesis in breast cancer cells. To this end, we have determined the growth response to inhibition of the PI3K/Akt signaling pathway in a series of breast cancer cell lines with different PTEN levels. The PTEN-negative cell line displayed greater sensitivity to the growth inhibitory effects of the PI3K inhibitor, LY294002 and rapamycin, an inhibitor of the PI3K/Akt downstream mediator mTOR, compared with the PTEN-positive cell lines. To determine whether or not these differences in response are specifically due to effects of PTEN, we developed a series of cell lines with reduced PTEN protein expression compared with the parental cell line. These reduced PTEN cells demonstrated an increased sensitivity to the anti-proliferative effects induced by LY294002 and rapamycin compared with the parental cells, which corresponded to alterations in cell cycle response. These findings indicate that inhibitors of mTOR, some of which are already in clinical development (CCI-779, an ester of rapamycin), have the potential to be effective in the treatment of breast cancer patients with PTEN-negative tumors and should be evaluated in this setting.     

ＰＩ３Ｋ／Ａｋｔ信号传导通路及其在结直肠癌中的研究进展

结直肠癌是常见的恶性肿瘤之一,近十年来,结直肠癌在我国的发病率呈逐年上升的趋势。已有研究表明,ＰＩ３Ｋ／Ａｋｔ信号传导通路是与细胞增殖和细胞凋亡关系最密切的信号传导通路之一。随着ＰＩ３Ｋ／ＡＫｔ信号通路在结直肠癌发生、发展中的研究不断深入,该通路对结直肠癌发生、发展及治疗药物的研发具有十分重要的价值。本文就ＰＩ３Ｋ／Ａｋｔ信号传导通路在结直肠癌发生、发展和治疗中的作用以及机制的研究进展作一综述。     

Alisol A attenuates malignant phenotypes of colorectal cancer cells by inactivating PI3K/Akt signaling

Despite the advancement in the diagnosis and therapeutic strategies for colorectal cancer, the outcomes of patients with colorectal cancer remain unsatisfactory. Alisol A is a natural constituent of Alismatis rhizoma (zexie) and has demonstrated anti-cancer properties; however, the function of Alisol A in colorectal cancer is still unknown. In the present study, the effect of Alisol A on colorectal cancer progression was investigated. MTT and colony formation assays showed that treatment with Alisol A repressed colorectal cancer cell proliferation in a dose-dependent manner. Similarly, western blot analysis demonstrated that Alisol A upregulated E-cadherin protein expression levels, but downregulated N-cadherin and Vimentin protein expression levels in colorectal cancer cells. In addition, the number of cells in G₀/G₁ phase was enhanced, while that of S phase was reduced in Alisol A-treated colorectal cancer cells. Apoptosis and pyroptosis of colorectal cancer cells were stimulated following treatment with Alisol A. Alisol A suppressed the migration ability of colorectal cancer cells in a dose-dependent manner. Moreover, Alisol A increased the chemotherapeutic sensitivity of colorectal cancer cells to cisplatin. Mechanically, western blot analysis confirmed that Alisol A repressed the phosphorylation levels of PI3K, Akt and mTOR in colorectal cancer cells. The Akt activator, SC79 reversed the effect of Alisol A on colorectal cancer cell proliferation and apoptosis. In conclusion, Alisol A induced an inhibitory effect on colorectal cancer progression by inactivating PI3K/Akt signaling.     

PI3K、Akt以及PTEN在胃肠道间质瘤中的表达及意义

目的:探讨PI3K、Akt以及PrEN的表达与GIST临床病理特征及预后的相关性,并探讨它们间的相互关系,以揭示其在GIST发生发展过程中的作用,为进一步的肿瘤靶点治疗提供理论依据.方法:选择临床病理资料完整、随访结果确切的中国医科大学附属盛京医院1990年-2007年2月手术切除、病理证实的GIST新鲜组织标本124例.男性64例、女性60例,平均年龄54.6岁.RT-PCR检测PI3K、Akt以及PTEN在GIST及对照组的mRNA水平.结果:PI3K mRNA水平随NIH分级表达上调(P＜0.05),PI3K的阳性表达率与黏膜受侵和肿瘤侵袭转移均显著相关(P＜0.05).Akt mRNA水平随NIH分级表达上调,其中在高、中危肿瘤组之间不明显,无统计学意义,其余各组有意义;Akt的阳性表达率与肿瘤侵袭转移和黏膜受侵显著相关,提示Akt的过表达促进了GIST的肿瘤侵袭转移.同时PTENmRNA随NIH分级表达下调(P＜0.05),随着肿瘤恶性程度的增加,PTEN的缺失率增高;PTEN的阳性表达率与肿瘤侵袭转移和黏膜受侵关系密切.结论:PI3 K/Akt与PTEN在GIST的发生发展中可能互相拮抗共同作用,PI3K、Akt蛋白阳性表达之间呈显著正相关(r =0.292.P=0.031);PI3K与PTEN蛋白阳性表达之间呈显著负相关(r=-0.412,P =0.036);PTEN与Akt蛋白阳性表达之间呈显著负相关(r=-0.386,P=0.024).     

胃肠道间质瘤PI3K-Akt信号转导通路介导的细胞凋亡相关因子的检测及其意义

目的:研究P13K/Akt信号转导通路介导的细胞凋亡相关因子在胃肠道间质瘤(GIST)中的表达及意义.方法:RT-PCR检测P13K、NF-κB、XIAP、bcl-2与survivin在:124例GIST及癌旁正常组织中mRNA水平.结果:在GIST中,PI3K、NF-κB mRNA表达与NIH分级、肿瘤侵袭转移、黏膜受侵密切相关,而与年龄、性别、组织学类型无关.XIAP mRNA随NIH分级表达上调;XIAP表达与GIST组织分化程度呈负相关,即分化程度越低,XIAP阳性表达率愈高,伴有肿瘤侵袭转移的GIST病例XIAP表达水平较高,同时XIAP的表达与黏膜受侵密切相关,而与年龄、性别、组织学类型无关.bcl-2 mRNA水平表达上调,与NIH分级、黏膜受侵有关,而与年龄、性别、组织学类型、转移复发及周围组织浸润无关.survivin mRNA在GIST中的表达与NIH分级、肿瘤侵袭转移、黏膜受侵等因素有关,而与年龄、性别以及组织学类型无关.由于NF-κB的调控作用,各指标之间mRNA的水平变化旱正相关.结论:GIST中PI3K/Akt信号转导通路的活化可以进一步激活NF-κB mRNA,从而进入细胞核内调控凋亡相天因子XIAP、bcl-2以及survivin mRNA水平的表达.     

PI3K/Akt途径在朊蛋白介导胃癌耐药中的作用研究

目的:探讨PI3K/Akt途径在朊蛋白(PrPc)介导胃癌耐药中的作用.方法:脂质体基因转染法建立高表达PrPc的胃癌细胞亚系.Western印迹检测转染细胞中Akt蛋白的表达.噻唑蓝(MTT) 比色法测定单独或联用PI3K抑制剂LY294002时转染细胞对化疗药物的敏感性.流式细胞仪检测单独或联用LY294002时转染细胞内阿霉素蓄积和潴留.结果:将PrPc正义载体pcDNA-PrP转入SGC7901,成功建立PrPc高表达胃癌细胞亚系并命名为PS;空载体转染细胞命名为BS.Western-Blot显示磷酸化Akt在PS中的表达较BS及SGC7901增高,而三者的总Akt则无差别.未经LY294002处理时,在阿霉素或长春新碱的作用下,PS的存活率分别为91.4%±3.4%和89.4%±3.8%,较BS(79.2%±4.3%和75.9%±2.1%)明显增高(均 ),PS细胞内阿霉素蓄积量和潴留量分别为4.4±0.3和4.2±0.4,明显低于BS(8.2±0.5和8.0±0.3)(均 );当联合LY294002处理后,PS在两种药物作用下的存活率均随着LY294002浓度的增加逐渐降低,并均在LY294002为30μmol/L时接近BS(均 ),PS细胞内阿霉素蓄积量和潴留量逐渐增高,并均在LY294002为30μmol/L时接近BS(均 ).结论:PrPc介导的胃癌耐药与PI3K/ Akt途径活性密切相关,抑制PI3K/ Akt途径活性可逆转PrPc介导的胃癌耐药.     

PTEN promoter methylation and activation of the PI3K/Akt/mTOR pathway in pediatric gliomas and influence on clinical outcome

The signaling pathways that underlie the pathogenesis of pediatric gliomas are poorly understood. We characterized the PI3K/Akt/mTOR pathway in pediatric gliomas of all grades. Using immunohistochemistry, we assessed activation of the PI3K/Akt/mTOR pathway by evaluating the downstream signaling molecules phospho(p)-S6, phospho(p)-4BP1, and phospho(p)-PRAS40; PTEN; and PTEN promoter methylation, as well as the MIB labeling index. We correlated these findings with the clinical outcomes of 48 children with gliomas. Eighty percent of high-grade gliomas (12/15) showed activation of the PI3K/Akt/mTOR pathway based on p-S6 and p-4EBP1 expression. The majority of high-grade gliomas were negative for PTEN expression (10/15), and 50% had PTEN promoter methylation (grade III: 2/4; grade IV: 3/6). Low-grade gliomas demonstrated PI3K/Akt/mTOR pathway activation in 14/32 (43.8%) by p-S6 and 16/32 (50%) by p-4EBP1. Over 50% of grade I (6/11) and almost all grade II tumors (6/7) showed PTEN promoter methylation. Tumor grade correlated negatively with PTEN expression and positively with expression of p-S6 and p-4EBP1 (PTEN: P = .0025; pS6: P = .0075; p-4EBP1: P = .0066). There was a trend toward inverse correlation of methylation of the PTEN promoter with expression of PTEN protein (P= .0990) and direct correlation of expression of p-S6 and p-4EBP1 with poorer clinical outcome, as measured by progression-free survival (p-S6: P= .0874; p-4EBP1: P= .0475). Tumors with no PTEN expression had a higher MIB labeling index (P= .007). The majority of pediatric gliomas show activation of the PI3K/Akt/mTOR pathway, with methylation of the PTEN promoter occurring commonly in these tumors.     

miR-93 Promotes Cell Proliferation in Gliomas through Activation of PI3K/Akt Signaling Pathway

The PI3K/Akt signaling pathway is frequently activated in various human cancer types and plays essential roles in development and progression of cancers. Multiple regulators, such as phosphatase and tensin homolog (PTEN) and PH domain leucine rich repeat protein phosphatases (PHLPP), have also found to be involved in suppression of the PI3K/Akt signaling pathway. However, how suppressive effects mediated by these regulators are concomitantly disrupted in cancers, which display constitutively activated PI3K/Akt signaling, remains puzzling. In the present study, we reported that the expression of miR-93 was markedly upregulated in glioma cell lines and clinical glioma tissues. Statistical analysis revealed that miR-93 levels significantly correlated with clinicopathologic grade and overall survival in gliomas. Furthermore, we found that overexpressing miR-93 promoted, but inhibition of miR-93 reduced, glioma cell proliferation and cell-cycle progression. We demonstrated that miR-93 activated PI3K/Akt signaling through directly suppressing PTEN, PHLPP2 and FOXO3 expression via targeting their 3′UTRs. Therefore, our results suggest that miR-93 might play an important role in glioma progression and uncover a novel mechanism for constitutive PI3K/Akt activation in gliomas.