PI3K/AKT/mTOR信号通路及其在卵巢癌治疗中的应用

卵巢癌是女性生殖系统常见的恶性肿瘤,发病率居于妇科恶性肿瘤第三位,死亡率居于妇科恶性肿瘤之首。目前对卵巢癌的标准治疗包括肿瘤细胞减灭术及卡铂和紫杉醇的联合化疗。PI3K/AKT/mTOR信号通路在卵巢癌的细胞增殖、侵袭、细胞周期进展、血管生成及耐药中发挥重要作用,是卵巢癌中最常发生改变的细胞内途径。本文对PI3K/AKT/mTOR信号通路及其在卵巢癌增殖和进展中的影响、PI3K/AKT/mTOR信号通路抑制剂在卵巢癌中的治疗应用做简要综述。     

沉默脂肪细胞增强子结合蛋白2通过PI3K/Akt途径抑制肝癌细胞增殖和迁移

脂肪细胞增强子结合蛋白2(AEBP2)作为多梳抑制复合物2(PRC2)的组成蛋白质,参与多种肿瘤细胞的增殖和迁移,然而其在肝癌中的作用尚不清楚。本研究基于UALCAN和Kaplan-Meier Plotter数据库分析发现,AEBP2在肝癌组织中高表达,并且与患者的不良预后呈正相关。实时荧光定量PCR和蛋白质印迹结果证实,AEBP2在肝癌细胞中的表达高于正常肝细胞。在HepG2和Huh-7细胞中转染AEBP2 siRNA,平板克隆、CCK-8、流式细胞术、划痕愈合和Transwell结果显示,沉默AEBP2可以抑制肝癌细胞增殖、迁移和侵袭,并促进细胞凋亡(P＜0.05)。免疫荧光检测和蛋白质印迹结果显示,沉默AEBP2能够抑制肝癌细胞上皮-间质转化(EMT)(P＜0.05)。生物信息学分析结果表明,AEBP2参与调控PI3K/Akt信号通路。蛋白质印迹结果证实,沉默AEBP2能下调PI3K、p-AKT (S473)、mTOR、MMP-2和MMP-9的蛋白质表达水平(P＜0.05)。此外,沉默AEBP2对HepG2细胞迁移和侵袭的影响可被PI3K/Akt通路激动剂胰岛素样生长因子1(IGF-1)部分逆转(P＜0.01)。综上所述,AEBP2可能通过调节PI3K/Akt途径促进肝癌细胞增殖和迁移。本研究为AEBP2在肝癌中的作用提供理论依据。     

Effects of streptozotocin-induced type 1 maternal diabetes on PI3K/AKT signaling pathway in the hippocampus of rat neonates

Diabetes in pregnancy impairs hippocampus development in offspring, leading to behavioral problems and learning deficits. Phosphatidylinositol 3-kinase/protein kinase B (PKB/Akt) signaling pathway plays a pivotal role in the regulation of neuronal proliferation, survival and death. The present study was designed to examine the effects of maternal diabetes on PKB/Akt expression and phosphorylation in the developing rat hippocampus. Wistar female rats were maintained diabetic from a week before pregnancy through parturition and male offspring was killed at first postnatal day (P1). The hippocampal expression and phosphorylation level of PKB/Akt, one of the key molecules in PI3K/AKT signaling pathway, was evaluated using real-time polymerase chain reaction (PCR) and western blot analysis. We found a significant bilateral downregulation of AKT1 gene expression in the hippocampus of pups born to diabetic mothers (p?<?0.05). Interestingly, our results revealed a marked upregulation of Akt1 gene in insulin-treated group compared with other groups (p?<?0.05). The western blot analysis also showed the reduction of phosphorylation level of all AKT isoforms in both diabetic and insulin-treated groups compared with control (p?<?0.05). Moreover, the results showed a significant increase in phosphorylation level of AKT in insulin-treated group compared with the diabetic group. These results represent that diabetes during pregnancy strongly influences the regulation of PKB/AKT in the developing rat hippocampus. Furthermore, although the control of glycemia by insulin administration is not sufficient to prevent the alterations in PKB/Akt expression, it modulates the phosphorylation process, thus ultimately resulting in a situation comparable to that found in the normal condition.     

MT1过表达可通过抑制PI3K/AKT/mTOR信号通路影响SKOV3细胞的增殖与凋亡

卵巢癌是一种常见的威胁女性健康的恶性肿瘤。然而卵巢癌的发生机制尚不清楚。该研究旨在探讨褪黑激素受体MT1在人卵巢癌SKOV3细胞中的作用及其主要机制。采用MT1-pcDNA3.1质粒(MT1组)与空载体pcDNA3.1(对照组)转染SKOV3细胞,未转染SKOV3细胞作为阴性对照组。转染48 h后,新鲜培养基培养24 h或48 h,观察细胞周期、增殖、凋亡情况,上清液检测褪黑激素表达。此外,在血清缺乏培养基培养细胞并转48 h后,更换新鲜培养基并加入4μmol/L PF-04691502抑制剂孵化24 h。测定AKT蛋白水平、总mTOR蛋白水平和相应磷酸化蛋白水平。结果显示,与NC组相比,MT1组在细胞周期S期阻滞(P<0.05),伴随增殖减少和早期凋亡(P<0.05)。3组细胞上清液检测到褪黑激素分泌均随时间增加(P<0.05)。Western blot分析显示,MT1过表达抑制了PI3K/AKT/mTOR信号通路的激活。该研究得出,SKOV3细胞有自行分泌褪黑激素的能力。MT1过表达可与内源性褪黑激素结合,抑制PI3K/AKT/mTOR信号通路的激活,最终发挥抗癌作用。     

Inhibition of fatty acid synthase suppresses U-2 OS cell invasion and migration via downregulating the activity of HER2/PI3K/AKT signaling pathway in vitro

FASN plays an important role in the malignant phenotype of various tumors. Our previous studies show that inhibition FASN could induce apoptosis and inhibit proliferation in human osteosarcoma (OS) cell in vivo and vitro. The aim in this study was to investigate the effect of inhibition FASN on the activity of HER2/PI3K/AKT axis and invasion and migration of OS cell. The expression of FASN, HER2 and p-HER2(Y1248) proteins was detected by immunohistochemistry in OS tissues from 24 patients with pulmonary metastatic disease, and the relationship between FASN and p-HER2 as well as HER2 was investigated. The results showed that there was a positive correlation between FASN and HER2 as well as p-HER2 protein expression. The U-2 OS cells were transfected with either the FASN specific RNAi plasmid or the negative control RNAi plasmid. FASN mRNA was measured by RT-PCR. Western blot assays was performed to examine the protein expression of FASN, HER2, p-HER2(Y1248), PI3K, Akt and p-Akt (Ser473). Migration and invasion of cells were investigated by wound healing and transwell invasion assays. The results showed that the activity of HER2/PI3K/AKT signaling pathway was suppressed by inhibiting FASN. Meanwhile, the U-2OS cells migration and invasion were also impaired by inhibiting the activity of FASN/HER2/PI3K/AKT. Our results indicated that inhibition of FASN suppresses OS cell invasion and migration via down-regulation of the “HER2/PI3K/AKT” axis in vitro. FASN blocker may be a new therapeutic strategy in OS management.     

miR-20a靶向CCND1作用PI3K/AKT信号通路抑制皮肤鳞状细胞癌的发展

摘要 目的：探究miR-20a与CCND1蛋白在皮肤鳞状细胞癌（CSCC）中的作用关系,以及其可能涉及的信号通路分子机制。方法：分别收集皮肤鳞状细胞癌患者的皮肤癌组织及其邻近正常皮肤组织,采用qRT-PCR分析组织中miR-20a和CCND1基因表达水平。为探究miR-20a对CSCC细胞的影响,将SCL-1细胞分为对照组（不转染）、miR-NC组（转染miR-NC）和miR-20a mimics组（转染miR-20a mimics）;为探究CCND1与PI3K/AKT信号通路的关系,将SCL-1细胞分为对照组（不转染）、si-NC组（转染si-NC）和si-CCND1组（转染si-CCND1）;为探究miR-20a与CCND1间的作用关系及对CSCC细胞的影响,将SCL-1细胞分为miR-NC组（转染miR-NC）、miR-20a mimics组（转染miR-20a mimics）、mimics+pcDNA组（共转染miR-20a mimics和pcDNA）和mimics+CCND1组（共转染miR-20a mimics和pcDNA-CCND1）。采用Western blot分析p-AKT、AKT、p-PI3K、PI3K和GSK-3β蛋白表达水平;采用MTT检测细胞增殖情况;采用流式细胞术检测细胞凋亡情况;采用Transwell分析细胞迁移和侵袭情况;采用双荧光素酶报告基因检测分析miR-20a与CCND1的靶向关系。结果：CSCC癌组织和SCL-1中miR-20a均低表达,CCND1高表达。与对照组和miR-NC组比较,miR-20a mimics组SCL-1细胞增殖水平以及侵袭和迁移数量均降低（P<0.05）,SCL-1细胞凋亡水平升高（P<0.05）,PI3K和AKT蛋白磷酸化水平降低（P<0.05）。TargetScanHuman数据库分析和双荧光素酶报告基因检测结果显示miR-20a与CCND1存在靶向作用关系。与对照组和si-NC组比较,si-CCND1组SCL-1细胞中CCND1和GSK-3β蛋白表达水平以及PI3K和AKT蛋白磷酸化水平均降低（P<0.01）。与miR-20a mimics组或mimics+pcDNA组比较,mimics+CCND1组SCL-1细胞增殖水平以及侵袭和迁移数量均升高（P<0.05）,SCL-1细胞凋亡水平降低（P<0.05）,PI3K和AKT蛋白磷酸化水平均升高（P<0.05）。结论：过表达miR-20a可能通过靶向抑制CCND1的表达而抑制PI3K/AKT信号通路的激活,从而抑制CSCC细胞的增殖、侵袭和迁移,并促进癌细胞凋亡。     

白藜芦醇经PI3K/Akt/mTOR信号通路诱导人肾癌786-O细胞自噬

白藜芦醇(resveratrol)可抑制人肾癌786-O细胞增殖,并诱导其凋亡,但是白藜芦醇对786-O细胞自噬(autophagy)的影响及机制尚不清楚.为探究其机制,体外培养786-O细胞,采用CCK-8检测786-O细胞活力;TUNEL染色检测786-O细胞凋亡;透射电子显微镜观察786-O细胞自噬体;吖啶橙染色...     

RHCG基因在非小细胞肺癌中的表达及对细胞增殖的影响

为了探讨Rh type C glycoprotein (RHCG)对非小细胞肺癌(non-small cell lung cancer,NSCLC)细胞增殖的影响及可能的作用机制,本研究使用荧光定量PCR法检测12对NSCLC及癌旁组织样本中RHCGmRNA的表达水平及pcDNA3.1-RHCG质粒对A549细胞RHC...     

P13K／AKT信号转导通路与人舌鳞癌细胞TCA8113顺铂耐药的相关性研究

目的：探讨P13K特异性抑制剂LY294002逆转顺铂耐药口腔鳞癌细胞TCA8113／CDDP的可行性。方法：采用间歇性加药,逐步递增CDDP药量,体外连续诱导培养TCA8113／CDDP细胞;用不同浓度的LY294002和顺铂处理TCA8113和TCA8113／CDDP细胞;MTT法观察对细胞增殖的影响,Western印迹分析LY294002作用前后p-Akt、Akt、P13K蛋白的表达。结果：建立了舌鳞癌耐药细胞TCA8113／CDDP,耐药指数为7．7;MTT实验显示LY294002对TCA8113和TCA8113／CDDP细胞的抑制作用与浓度及作用时间呈正相关;LY294002联合顺铂对2种细胞的抑制作用比单用顺铂效果好;P13K、Akt、P—AKT蛋白表达明显降低,其中TCA8113／CDDP细胞中P13K、AKT、p-AKT蛋白的表达比TCA8113细胞明显增多（P〈0．05）。结论：LY294002能增加耐药口腔鳞癌顺铂化疗的敏感性。     

辅酶Q10B调控PI3K/AKT信号通路促进食管鳞癌恶性生物学行为的分子机制研究

摘要 目的：探讨辅酶Q10B（COQ10B）影响食管鳞癌细胞恶性生物学行为的分子机制。方法：采用qRT-PCR检测3种人ESCC细胞系（KYSE150、KYSE450和TE-1）和食管上皮细胞系Het-1A细胞中COQ10B表达情况。对敲减COQ10B的KYSE150细胞进行RNA测序筛选差异表达基因,通过KEGG通路分析寻找密切相关信号通路。利用慢病毒构建COQ10B过表达KYSE150和TE-1细胞稳转株,Western blot方法检测过表达效率。采用CCK8法检测PI3K/AKT信号通路抑制剂LY294002对食管鳞癌细胞的半抑制浓度（IC₅₀）值。通过EDU、平板克隆实验、流式细胞术、创面愈合实验、Transwell侵袭小室检测过表达COQ10B以及加入LY294002抑制剂后对食管鳞癌细胞增殖、凋亡、迁移及侵袭能力的影响。同时采用Western blot技术检测过表达COQ10B以及加入LY294002抑制剂后对KYSE150食管鳞鳞癌细胞中PI3K/AKT信号通路相关蛋白（PI3K、AKT、p-PI3K和p-AKT）表达的影响。结果：COQ10B在ESCC细胞系中相对高表达。RNA-seq筛选出显著性差异表达基因共319个,包括285个上调基因、34个下调基因,通过KEGG通路分析筛选出PI3K/AKT信号通路作为后续分子机制的研究对象。PI3K/AKT信号通路抑制剂LY294002随浓度和作用时间的增加,对食管鳞癌细胞的毒性作用增强,后续实验中使用LY294002作用48 h的IC₅₀值左右的药物浓度。与阴性对照组相比,在KYSE150和TE-1食管鳞癌细胞中过表达COQ10B后可显著增强细胞的增殖、迁移及侵袭并抑制其凋亡。然而,在加入LY294002抑制剂处理48h后,COQ10B过表达所增强的ESCC细胞增殖、迁移、侵袭能力均被显著抑制,而凋亡能力的抑制被逆转。同时与阴性对照组相比,KYSE150食管鳞癌细胞中过表达COQ10B后PI3K/AKT信号通路中p-PI3K、p-AKT蛋白表达水平显著升高。而在加入LY294002抑制剂处理48 h后可显著抑制COQ10B过表达所增强的PI3K/AKT信号通路相关蛋白p-PI3K、p-AKT表达水平。结论：COQ10B可通过激活PI3K/AKT信号通路促进食管鳞癌细胞的增殖、迁移、侵袭,并抑制其凋亡。