EBV-BZLF1通过激活PI3K/AKT信号通路促进胃癌细胞生长

  目的   明确EB病毒（Epstein-Barr virus,EBV）BZLF1基因（EBV-BZLF1）对EB病毒阴性胃癌细胞生物学行为的影响及可能的分子机制。   方法   运用过表达BZLF1的慢病毒感染胃癌细胞系AGS和HGC27,分别采用CCK8、细胞凋亡检测、细胞迁移和侵袭实验及Western blot法检测细胞的增殖能力、细胞凋亡与迁移侵袭能力及细胞信号通路变化情况。将过表达BZLF1的胃癌细胞HGC27注射于非肥胖糖尿病/重症联合免疫缺陷（NOD/SCID）小鼠背部皮下构建移植瘤模型,观察BZLF1对肿瘤生长的影响。   结果   过表达BZLF1的慢病毒感染组AGS-BZLF1与HGC27-BZLF1相比亲本细胞,细胞中BZLF1蛋白表达明显上调;体外细胞增殖与小鼠体内成瘤能力均显著增强（P < 0.05）;细胞凋亡受到BZLF1蛋白的抑制,其中AGS-BZLF1和HGC27-BZLF1凋亡率为（2.40± 0.14）%和（3.90±0.14）%,显著低于AGS和HGC细胞的（5.75±0.35）%和（9.70±0.42）%（P < 0.05）;但细胞迁移和侵袭能力无明显改变。深入分子机制研究发现,BZLF1表达上调后,PI3K/AKT信号通路明显激活,表现为pAKT和pS6蛋白表达上调。使用BEZ235抑制剂阻断PI3K/AKT信号通路后,HGC27-BZLF1和AGS-BZLF1细胞的生长均受到抑制。   结论   EBV-BZLF1可通过激活PI3K/ AKT信号通路促进胃癌细胞生长,靶向PI3K/AKT通路抑制剂或可成为EBV阳性胃癌的治疗选择。      

CDO1通过PI3K/AKT信号通路调控胃癌细胞增殖及细胞周期

目的:探讨半胱氨酸双加氧酶1(CDO1)对胃癌细胞增殖、细胞周期的调控机制。方法:用脂质体法将si-NC组（转染si-NC）、si-CDO1组（转染si-CDO1）、pcDNA组（转染pcDNA）、pcDNA-CDO1组（转染pcDNA-CDO1）、pcDNA-CDO1+DMSO组（转染pcDNA-CDO1并用DMSO处理）、pcDNA-CDO1+IGF-1组（转染pcDNA-CDO1并用IGF-1处理）转染至AKG细胞。用实时荧光定量逆转录聚合酶链反应（qRT-PCR）、免疫印迹（Western blot）、细胞计数试剂盒（CCK-8）、流式细胞术检测细胞CDO1、PI3K、Akt、p-Akt蛋白的表达、细胞增殖、细胞周期。结果:与人胃黏膜上皮细胞GES-1相比,胃腺癌细胞AKG中CDO1的表达明显降低（P<0.05）;与si-NC组相比,si-CDO1组AKG细胞的增殖明显上调,细胞发生明显的S期、G2/M期阻滞,过表达CDO1则具有相反的作用。重要的是,敲减CDO1可上调PI3K/AKT信号通路关键基因PI3K、p-Akt的表达,而过表达CDO1具有相反的作用。激活PI3K/AKT信号通路后,过表达CDO1对胃癌细胞的增殖、细胞周期的调控作用可被部分逆转。结论:CDO1可抑制胃癌细胞的增殖,调控细胞周期,其机制与抑制PI3K/AKT信号通路的活性有关,将为胃癌的治疗提供参考。     

PI3K/AKT信号通路与前列腺癌关系的研究进展

近年来针对前列腺癌靶向治疗的研究作为新的热点受到越来越多的关注,主要集中在非AR途径的通路及靶点的探索,其中较为成熟且具有明显研究价值的途径之一是磷脂酰肌3-羟激酶(PI3K)/丝氨酸-苏氨酸蛋白激酶(AKT)信号通路.研究表明,该信号通路的异常活化与疾病的发展和转归有显著相关性,在机体细胞的生长、增殖、凋亡以及炎症反...     

PI3K/AKT/mTOR信号通路介导乳腺癌内分泌治疗耐药的研究进展

内分泌治疗在激素受体阳性乳腺癌患者中的地位越来越受到重视,可以明显改善患者预后.内分泌治疗耐药严重制约着其临床应用,但耐药机制仍不明确,目前认为多信号通路激活参与耐药形成,其中PI3K/AKT/mTOR信号通路在耐药机制中发挥重要作用.临床试验提示,在内分泌治疗的基础上阻断信号通路可以逆转耐药,研究结果令人鼓舞.本文对PI3K/AKT/mTOR信号通路在内分泌耐药机制中的作用进行综述.     

溶血磷脂酸通过调控PI3K/AKT信号通路对骨肉瘤细胞黏附和迁移的作用

摘 要：［目的］ 研究溶血磷脂酸（lysophosphatidic acid,LPA）在骨肉瘤细胞黏附和迁移中的作用及其相关分子机制。［方法］通过黏附和划痕实验观察细胞黏附和迁移能力;q-PCR和Western blot检测骨肉瘤细胞系(Mg-63,SaOS-2,HOS-8603)中溶血磷脂酸受体（lysophosphatidic acid receptor,LPAR）的表达,分析LPAR的表达与肿瘤细胞迁移侵袭之间的关系;黏附和划痕实验检测LPA处理后对骨肉瘤细胞黏附和迁移的影响;Western Blot检测LPA对骨肉瘤细胞黏附和迁移相关信号通路蛋白的影响。［结果］ 细胞黏附和迁移能力检测结果显示Mg-63细胞的黏附和迁移能力最强,SaOS-2细胞黏附和迁移能力最弱。细胞中LPAR检测结果显示Mg-63、SaOS-2、HOS-8603三株细胞中LPAR1、LPAR2、LPAR3均有不同程度的表达,其中Mg-63细胞中LPAR1、LPAR2、LPAR3表达均为最高。LPA处理SaOS-2细胞后,其黏附和迁移能力均明显下降;Western Blot结果显示LPA处理后,SaOS-2细胞中PI3K、p-AKT、CD44表达均明显上调。［结论］ LPA可能主要通过PI3K/AKT通路促进骨肉瘤细胞黏附和迁移。     

PI3K/AKT/mTOR信号通路抑制剂在淋巴瘤中的研究进展*

磷脂酰肌醇-3 激酶（phosphatidylinositol 3-kinase,PI 3K）- 蛋白激酶B（protein kinaseB ,PKB ,又称AKT ）- 雷帕霉素靶蛋白（mammalian target of  rapamycin,mTOR）信号通路与细胞的生长、增殖、分化、凋亡、代谢等密切相关,在多种实体肿瘤中已发现该信号通路的异常。近年来,以抑制该通路特定位点的靶向治疗已成为抗肿瘤的研究热点。许多该位点新型抑制剂也已进入淋巴瘤的临床试验中,本文就该通路在淋巴瘤中的活化状态及各个分子靶点抑制剂的研究进展做一综述。     

PFKFB3通过调控PI3K/AKT信号通路促进骨肉瘤细胞的增殖及转移

目的:探讨6-磷酸果糖2-激酶/果糖-2,6-二磷酸酶3(6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3,PFKFB3)对骨肉瘤细胞增殖、凋亡、迁移及侵袭的影响,及可能的作用机制.方法:采用实时荧光定量PCR法、蛋白质印迹法及免疫组织化学法检测骨肉瘤组织及其相...     

PI3K/AKT/mTOR信号通路抑制剂治疗结直肠癌的研究进展

PI3K/AKT/mTOR通路的异常活化在结直肠癌的发生发展中起到重要作用,以此通路为靶点的药物已成为结直肠癌治疗的研究热点,临床前和临床试验研究证明,针对PI3K/AKT/mTOR通路的多种抑制剂具有抗肿瘤活性。越来越多的临床数据显示,PTEN缺乏或PIK3CA基因突变对PI3K/AKT/mTOR通路抑制剂敏感,KRAS突变则预示着耐药;寻找针对这一通路抑制剂敏感的优势人群也成为结直肠癌的研究热点;此外,PI3K/AKT/mTOR通路也会影响常规治疗的疗效,因此PI3K/AKT/mTOR通路抑制剂联合细胞毒治疗方案在结直肠癌中可能起到协同作用。     

PI3K/AKT/mTOR信号通路在三阴性乳腺癌中的作用及靶向治疗研究进展

摘 要：三阴性乳腺癌（triple negative breast cancer,TNBC）是一种特殊类型的乳腺癌亚型,占所有乳腺癌的15%,具有高度异质性。目前临床上以化疗为主要治疗手段,但效果并不理想。全文主要介绍了TNBC的生物学特点、分子分型和重要相关通路,其中PI3K/AKT/mTOR 信号传导通路在TNBC中尤为重要,该通路上的相关靶点为TNBC提供了更好的精准治疗。     

淫羊藿素通过PI3K/AKT信号通路抑制非小细胞肺癌H460细胞增殖

目的:探讨淫羊藿素（icaritin）通过PI3K/AKT信号通路对非小细胞肺癌H460细胞增殖的影响。方法:采用MTT比色实验检测,不同浓度（0、5、10、20、40、80μmol/L）淫羊藿素处理H460细胞24、48、72h后细胞增殖抑制率,流式细胞仪检测不同浓度淫羊藿素对H460细胞凋亡的影响,Western blot实验检测不同浓度淫羊藿素对H460细胞中PI3K、AKT、p-AKT、Cleaved-Caspase-9蛋白质表达水平的影响。结果:淫羊藿素可抑制非小细胞肺癌H460细胞的增殖,并表现为剂量和时间依赖性（P＜0.05）。0、5、10、20μmol/L淫羊藿素处理H460细胞24h后,H460细胞凋亡率分别为（4.90±1.20）%、（13.5±2.32）%、（16.47±1.90）%和（27.43±3.15）%,P＜0.05。淫羊藿素可下调PI3K、AKT的表达水平,降低AKT的磷酸化(p-AKT)水平,上调Cleaved-Caspase-9表达水平(P＜0.05)。结论:淫羊藿素可能通过抑制PI3K/AKT信号通路激活,抑制H460细胞增殖。     

Profilin 2 Promotes Proliferation and Metastasis of Head and Neck Cancer Cells by Regulating PI3K/AKT/b-Catenin Signaling Pathway

Profilin 2 (PFN2) was found to be mainly expressed in neurons and involved in the development of the brain. In recent years, emerging evidence indicated that PFN2 is also significantly upregulated in various cancers including head and neck cancer (HNSC) and influences cancer cell proliferation, migration, and invasion. However, the role of PFN2 in HNSC development and progression remains unclear. The aim of our study was to investigate the role of PFN2 in the development of HNSC and its possible molecular mechanisms. Bioinformatics showed that increased expression of PFN2 in tumors correlated highly with poor prognosis of HNSC patients. Our results indicated that PFN2 was highly expressed in HNSC tissues and in HNSC cell lines. Knockdown of PFN2 inhibited proliferation, invasion, and migration of HNSC cells, while PFN2 overexpression produced the opposite effects. Using a nude mouse xenograft model, we substantiated the tumor-promoting effect of PFN2 on HNSC in vivo. Furthermore, we found that PFN2 downregulation reduced the phosphorylation of Akt and GSK-3 and reduced the expression of -catenin in HNSC cells. The opposite was observed when PFN2 was overexpressed. Collectively, these results suggest that PFN2 promotes the proliferation and metastasis of HNSC by activating the PI3K/Akt/ -catenin signaling pathway. Although further validation is needed, we speculate that PFN2 plays a crucial role in HNSC and may be a promising therapeutic target and prognostic biomarker.     

MiR-374a通过PTEN/AKT信号通路调节乳腺癌细胞的增殖和凋亡

摘 要：［目的］ 探讨miR-374a在乳腺癌细胞增殖和凋亡中的作用,并进一步探讨其机制。［方法］ 采用实时荧光定量PCR（qRT-PCR）检测人乳腺癌细胞MCF-7及正常人乳腺细胞Hs 578Bst的miR-374a及PTEN mRNA转录水平,Western blot法测定MCF-7、Hs 578Bst组细胞及对照、 miR-374a抑制剂组细胞的PTEN、p-AKT蛋白表达变化,用CCK-8法及Tunel法分别观察对照组和miR-374a抑制剂组细胞的增殖和凋亡,并用Western blot法检测两组细胞的凋亡相关蛋白Bcl-2、Cleaved caspase-3、Cleaved caspase-9表达。［结果］ 与人正常乳腺Hs 578Bst细胞相比,乳腺癌MCF-7细胞的miR-374a表达水平显著性增高（P<0.001）,PTEN mRNA及蛋白的表达水平显著性降低（P<0.001）,而p-AKT蛋白表达水平明显升高（P<0.001）。miR-374a抑制剂可抑制乳腺癌细胞的增殖（P<0.001）,并促进其凋亡的发生（P<0.001）,降低抗凋亡蛋白Bcl-2表达水平（P<0.001）的同时活化凋亡相关蛋白Caspase-3和Caspase-9（P<0.001）。miR-374a 通过靶点PTEN影响AKT通路,miR-374a组细胞PTEN mRNA表达水平显著性降低（P<0.001）,而miR-374a抑制剂处理后,PTEN蛋白水平显著性升高（P<0.001）,p-AKT表达降低（P<0.001）。［结论］ miR-374a在乳腺癌细胞高表达,并通过调节PTEN/AKT信号通路抑制乳腺癌细胞的增殖,促进凋亡的发生。miR-374a/PTEN/AKT信号通路有望成为乳腺癌的新治疗靶点。     

NOTCH通路依赖PI3K/AKT通路调控胶质瘤干细胞增殖和自我更新能力

目的 探讨NOTCH通路对胶质母细胞瘤细胞增殖和自我更新能力调控及其潜在机制。方法 体外培养LN-229、U118-MG和A172胶质瘤干细胞球;MTT实验和单细胞成球实验分别检测胶质瘤干细胞增殖和自我更新能力;靶向AKT1慢病毒载体shRNA和PI3K抑制剂LY294002抑制PI3K/AKT信号通路活性,检测NOTCH通路功能是否依赖PI3K/AKT通路;Western blot检测NOTCH通路和PI3K/AKT通路活性;BLISS独立模型评价NOTCH抑制剂DAPT和LY294002的相互作用。结果 LN-229、U118-MG和A172体外培养形成胶质瘤干细胞球;DAPT抑制NOTCH通路活性同时降低PI3K/AKT通路活性,且NOTCH通路对PI3K/AKT通路的调控不依赖于PTEN介导;DAPT抑制胶质瘤干细胞增殖和体外单细胞成球能力;ShAKT1和LY294002抑制PI3K/AKT通路活性,同时显著减弱DAPT对胶质瘤干细胞增殖和体外单细胞成球能力的抑制作用（P<0.05）,DAPT和LY294002联合使用产生拮抗作用。结论 NOTCH通路依赖于PI3K/AKT通路调控胶质瘤干细胞增殖和自我更新能力。     

LPA经PI3K/Akt信号转导通路抑制顺铂诱导卵巢癌细胞凋亡

 目的 研究PI3K/AKT信号转导通路对LPA保护顺铂诱导的卵巢癌SKOV3细胞凋亡作用的影响。 方法 MTT法检测LPA和LY294002对DDP作用后的SKOV3细胞增殖活性的影响;Hoechst33258荧光染色 观察凋亡细胞;FCM分析细胞凋 亡率;凝胶电泳观察凋亡细胞的DNA“梯状”条带;Western blot检测LPA、LY294002对磷酸 化Akt蛋白表达的影响。 结果 LPA+LY294002+DDP组对SKOV3细胞增殖的抑制作用、凋亡小体的产生及细胞凋亡率高于 LPA+DDP组(P<0.05),而与 LY294002+DDP组差异无统计学意义, DNA片段凝胶电泳示LPA作用后不产生明显的凋亡片段, LPA和LY294002同时作用可出现DNA断裂梯形条带。Western blot结果示LPA作用后磷酸化Akt 蛋白表达升高,而LY294002作用后,磷酸化Akt蛋白表达明显下降。 结论 LPA通过激活PI3K/Akt信号转导通路抑制顺铂诱导的卵巢癌细胞的凋亡。     

GRP78 Secreted by Colon Cancer Cells Facilitates Cell Proliferation via PI3K/Akt Signaling

Glucose regulated protein 78 (GRP78) is usually recognized as a chaperone in the endoplasmic reticulum. However, increasing evidence indicates that GRP78 can be translocated to the cell surface, acting as a signaling receptor for a variety of ligands. Since little is known about the secretion of GRP78 and its role in the progression of colon cancer we here focused on GRP78 from colon cancer cells, and purified GRP78 protein mimicking the secreted GRP78 was able to utilize cell surface GRP78 as its receptor, activating downstream PI3K/Akt and Wnt/β-catenin signaling and promote colon cancer cell proliferation. Our study revealed a new mode of action of autocrine GRP78 in cancer progression: secreted GRP78 binds to cell surface GRP78 as its receptor and activates intracellular proliferation signaling.     

The PI3K/AKT/MTOR Signaling Pathway: The Role of PI3K and AKT Inhibitors in Breast Cancer

Breast cancer is the second leading cause of cancer death in women. Targeted therapies are available for HER2-positive and endocrine-sensitive disease while chemotherapy remains the mainstay of treatment for triple-negative breast cancer. The efficacy of all targeted interventions is, however, limited by primary or secondary resistance. Preclinical data show that active PI3K/AKT/mTOR signaling contributes to therapy resistance in HER2-positive and hormone-receptor-positive breast cancer. In line with these preclinical observations, clinical trials such as BOLERO-2 demonstrated a benefit of additional inhibition of mTOR signaling in advanced estrogen-receptor-positive breast cancer patients refractory to prior aromatase-inhibitor therapy. Besides the mTOR, several other proteins involved in the PI3K-pathway serve as potential therapeutic targets, such as PI3K and AKT. In this review, we summarize the current available knowledge and experimental and clinical research results about targeting the PI3K-pathway in breast cancer and, thus, provide the rationale for PI3K- and AKT-inhibitor use in the clinic.     

塞来昔布通过PI3K/Akt通路调控胃癌细胞凋亡

探讨塞来昔布通过PI3K/Akt信号通路调控胃癌细胞凋亡的机制。方法：塞来昔布体外处理人胃癌细胞株SGC-7901后,透射电镜观察细胞超微结构的改变,实时荧光定量RT-PCR法和Western Blot法检测蛋白激酶B（Akt）、天冬氨酸特异性半胱氨酸蛋白酶-8（Caspase-8）、Caspase-9的表达。结果：塞来昔布处理细胞后,透射电镜下观察到典型凋亡小体和自噬体;实验组Akt mRNA表达水平的改变无统计学意义,P-Akt蛋白的表达下调并呈时间和剂量依赖性,差异有统计学意义（P<0.05或P<0.01）;Caspase-8 mRNA表达水平上调,呈时间和剂量依赖性,差异有统计学意义（P<0.05或P<0.01）;Caspase-9 mRNA表达水平较对照组均上调,但125 μmol/L塞来昔布作用24 h组mRNA表达量与对照组相比差异无统计学意义,48 h和72 h组与对照相比差异有统计学意义（P<0.05或P<0.01）。塞来昔布作用72 h后,75 μmol/L组Caspase-9 mRNA表达量与对照组相比差异无统计学意义,100 μmol/L和125 μmol/L组与对照相比差异有统计学意义（P<0.05或P<0.01）;procaspase-8和procaspase-9蛋白被活化,表达量下调,呈时间和剂量依赖性,差异有统计学意义（P<0.05或P<0.01）。结论：1）塞来昔布可能通过PI3K/Akt通路诱导细胞凋亡和细胞自噬两种程序性死亡方式导致细胞死亡。2）塞来昔布诱导胃癌细胞凋亡的分子机制为线粒体途径和死亡受体途径。     

VASH2 Promotes Cell Proliferation and Resistance to Doxorubicin in Non-Small Cell Lung Cancer via AKT Signaling

Vasohibin2 (VASH2), a proangiogenic factor, has been demonstrated to play an oncogenic role in some common human cancers. However, the detailed function of VASH2 in non-small cell lung cancer (NSCLC) has not previously been studied. In this study, we found that VASH2 was significantly upregulated in NSCLC tissues and cell lines, and its increased expression was associated with NSCLC progression and poor prognosis of patients. Knockdown of VASH2 markedly inhibited cell proliferation and P-glycoprotein expression in NSCLC cells. Overexpression of VASH2 enhanced cell proliferation, P-glycoprotein expression, as well as doxorubicin resistance in NSCLC cells. Moreover, the expression levels of VASH2 were significantly increased in newly established doxorubicin-resistant NSCLC cells. Molecular mechanism investigation revealed that inhibition of VASH2 expression in NSCLC cells suppressed the activity of AKT signaling, and overexpression of VASH2 enhanced the activity of AKT signaling. We further showed that downregulation of AKT signaling activity using AKT inhibitor LY294002 markedly inhibited NSCLC cell proliferation and resistance to doxorubicin induced by VASH2. In conclusion, the findings in the present study indicate that VASH2 promotes NSCLC cell proliferation and resistance to doxorubicin via modulation of AKT signaling. Thus, we suggest that VASH2 may become a potential therapeutic target for the treatment of NSCLC.