特异性微小RNA抑制剂对胃癌细胞增殖的影响

目的： 探讨特异性微小RNA抑制剂对胃癌细胞增殖的影响。方法: 设计并合成4种微小RNA（miR-17、miR-21、miR-106a和miR-421）的2’-甲氧修饰的RNA寡核苷酸（微小RNA抑制剂）,用脂质体分别转染到SGC-7901和MGC-803胃癌细胞,然后用实时定量逆转录-聚合酶链反应技术检测微小RNA的表达情况,最后用MTT方法检测胃癌细胞的增殖情况。结果: 4种微小RNA抑制剂均有效抑制了SGC-7901和MGC-803细胞中相应微小RNA的表达;除miR-21抑制剂未见抑制胃癌细胞的增殖外,其它3种微小RNA抑制剂均以剂量依赖方式抑制胃癌细胞的增殖且对SGC-7901的效果优于MGC-803。结论: 微小RNA的特异性抑制剂能有效抑制胃癌细胞的增殖,采用这种技术为研究胃癌的发病机制提供了新方法。     

siRNA沉默LBH基因促进人支气管上皮细胞周期进展

目的: 利用合成的小分子干扰RNA(siRNA)转染人支气管上皮细胞16HBE,观察LBH(limb-bud and heart) 基因表达下调对16HBE细胞周期及相关基因表达的影响。方法: 脂质体2000转染靶向LBH 基因的siRNA到16HBE细胞,荧光定量RT-PCR检测siRNA转染后LBH基因表达,流式细胞术检测LBH基因沉默后16HBE 细胞周期的改变,荧光定量RT-PCR及Western blotting检测LBH基因沉默后细胞周期素E1和E2表达水平。结果: 50 nmol/L siRNA转染16HBE细胞48 h后, LBH基因的表达水平只有对照组的14%;siRNA转染16HBE细胞48 h,其G₁期细胞百分率比对照组减少9.28%,而S期细胞百分比增加14.08%;16HBE细胞在50 nmol/L siRNA的转染后,细胞周期素E2的表达水平为对照组的2倍,而细胞周期素E1的表达没有发生明显改变。结论: 靶向于LBH基因的siRNA能有效沉默16HBE细胞中LBH基因的表达,LBH基因的表达下调促进了16HBE细胞周期G₁/S期的进展;细胞周期素E2的表达上调参与了LBH沉默导致的细胞周期G₁/S期的进展。     

Akt抑制剂perifosine抑制胃癌细胞增殖并诱导凋亡的实验研究

目的: 探讨新的Akt抑制剂perifosine对胃癌细胞增殖与凋亡的影响。方法: 采用MTT法检测perifosine对胃癌细胞SGC-7901细胞增殖的影响;流式细胞术分析细胞周期变化;AnnexinⅤ-FITC试剂盒检测细胞凋亡;免疫印迹法检测蛋白表达水平。结果: Perifosine能够抑制SGC-7901细胞的增殖,且抑制作用呈时间和剂量依赖性。胃癌细胞经perifosine处理后,细胞阻滞于G₂期,p21表达水平增加,而cyclin B1的表达受到抑制;凋亡诱导现象随着perifosine剂量的增加而增强。免疫印迹结果显示perifosine活化SGC-7901细胞内caspase-3﹑caspase-9及其底物多聚(ADP-核糖)聚合酶(PARP),促进凋亡诱导蛋白Bax的表达,并抑制Bcl-2的表达。结论: Perifosine对人胃癌细胞SGC-7901的生长具有显著的抑制作用,其凋亡诱导活性与调节caspase家族和Bcl-2家族蛋白的表达密切相关。     

反义PKCα对CNE-2Z细胞周期的影响

目的:观察蛋白激酶Cα亚型(PKCα)的反义寡核苷酸对鼻咽癌CNE-2Z细胞生长、细胞周期和cyclinE表达的影响。方法:脂质体法转染反义PKCα,MTT法测细胞生长,流式细胞仪检测细胞周期,免疫细胞化学及点印迹法检测cyclinE表达。结果:①随着反义PKCα的浓度增加,细胞生长指数逐渐降低(P＜0.01)。②反义PKCα使细胞G₁期百分比增高(P＜0.05)。③反义PKCα使细胞cyclinE的表达减弱,扫描定量反义PKCα组为对照组的66.5％±18.4％(P＜0.05)。结论:反义PKCα可通过抑制cyclinE表达、阻滞细胞于G₁期从而抑制CNE-2Z的生长。     

下调miR-221诱导胃癌细胞凋亡的机制及其化疗敏感性研究

目的 探究下调miR-221诱导人胃癌细胞凋亡的机制,及其对胃癌细胞化疗敏感性的影响。方法 实时荧光定量PCR检测正常胃黏膜上皮细胞NGEC与4种胃癌细胞系(SGC-7901、BGC-823、MGC803、MKN-28)中miR-221表达水平;将SGC-7901细胞随机分为5组:空白对照组(常规培养)、Anti-miR-NC组(转染inhibitor control)、Anti-miR-221组(转染miR-221 inhibitor)、AntimiR-221+siRNA-NC组(转染miR-221 inhibitor后再转染siRNA阴性对照)、Anti-miR-221+siRNA-Parkin组(转染miR-221 inhibitor后再转染siRNA-Parkin),Lipofectamine 2000脂质体介导法转染SGC-7901细胞。MTT法检测细胞活性; JC-1荧光探针检测线粒体膜电位; Western blot检测自噬相关蛋白的表达水平; Hoechst 33342染色和AnnexinⅤ-FITC/PI双染法检测细胞凋亡情况。使用不同浓度奥沙利铂(2.5、5、10、...     

MicroRNA-146a通过靶向TAK1诱导胃癌SGC-7901细胞凋亡

目的:观察微小RNA-146a(miR-146a)对胃癌SGC-7901细胞凋亡的影响及其可能的分子机制。方法:将miR-146a mimic(上调miR-146a表达)和miR-146a inhibitor(下调miR-146a表达)分别转染至人胃癌SGC-7901细胞中,同时设置miRNA无义序列转染为阴性对照组(NC组)。RT-q PCR检测转染后胃癌细胞miR-146a的表达水平;CCK-8法和流式细胞术检测miR-146a对SGC-7901胃癌细胞生长活力和凋亡的影响;RT-q PCR和Western blot法检测miR-146a上调或下调对转化生长因子β激活激酶1(TAK1)/核因子κB(NF-κB)通路的影响。结果:在SGC-7901细胞中,上调miR-146a表达显著促进细胞凋亡,而下调miR-146a表达则显著抑制细胞凋亡。与NC组相比,miR-146a mimics转染SGC-7901细胞后,TAK1的mRNA和蛋白表达均明显下降,差异均有统计学显著性(P0.05),而miR-146a inhibitors转染组TAK1的mRNA和蛋白质表达则显著增加(P0.05),提示miR-146a负调控TAK1表达。敲低TAK1促进SGC-7901细胞凋亡(P0.01),而TAK1过表达TAKI则抑制SGC-7901细胞凋亡(P0.01)。此外,过表达miR-146a和敲低TAK1均能显著上调NF-κB抑制蛋白α(IκBα)和下调B细胞淋巴瘤-2(Bcl-2)表达。结论:本研究结果表明miR-146a通过靶向TAK1抑制NF-κB途径,从而诱导胃癌细胞凋亡。     

Bmi-1 基因过表达对人正常胃黏膜上皮细胞株GES-1增殖的影响

目的: 探讨原癌基因B淋巴瘤莫洛尼鼠白血病病毒插入区1( Bmi-1 )过表达对人正常胃黏膜上皮细胞株GES-1增殖的影响。方法: 采用逆转录病毒介导转染方法将携带原癌基因 Bmi-1 的质粒或空质粒稳定转染GES-1细胞,通过real-time PCR及Western blotting在mRNA及蛋白水平鉴定转染效果。流式细胞术检测过表达 Bmi-1 对GES-1细胞周期的影响。应用CCK-8(Cell Counting Kit-8)试剂盒检测稳定转染 Bmi-1 对GES-1细胞增殖的影响。结果: Real-time PCR及Western blotting结果均表明成功建立稳定转染 Bmi-1 基因的GES-1细胞株。流式细胞术结果表明,过表达 Bmi-1 基因使GES-1细胞G₀/G₁期减少,G₂/M期和S期细胞增多。生长曲线显示,过表达 Bmi-1 基因使GES-1细胞增殖速度明显提高。结论: 过表达 Bmi-1 基因能调控GES-1细胞的细胞周期,促进GES-1细胞的增殖。     

siRNA下调astrocyteelevatedgene-1对神经母细胞瘤细胞增殖和凋亡影响的体外研究

目的: 探讨siRNA下调astrocyte elevated gene-1( AEG-1 )表达对神经母细胞瘤细胞增殖、凋亡和细胞周期的影响。方法: 用设计合成的AEG-1 siRNA转染神经母细胞瘤细胞株M17和SK-N-SH,采用荧光定量RT-PCR技术观察AEG-1 siRNA对 AEG-1 基因表达的影响;用MTT法和克隆形成实验观察AEG-1 siRNA对神经母细胞瘤细胞的增殖抑制作用;用流式细胞术检测下调 AEG-1 表达对神经母细胞瘤细胞凋亡及细胞周期的影响。结果: 用AEG-1 siRNA转染人神经母细胞瘤细胞,RT-PCR结果证实AEG-1 siRNA能显著基因下调 AEG-1 表达,与对照组相比有显著差异(P<0.01);MTT法和克隆形成实验结果证明下调 AEG-1 表达可显著抑制神经母细胞瘤细胞的增殖;流式细胞术检测结果表明下调 AEG-1 表达可促进神经母细胞瘤细胞凋亡,并将细胞周期阻滞在G₀/G₁期。结论: AEG-1 siRNA可下调基因在神经母细胞瘤细胞中表达,并抑制神经母细胞瘤细胞增殖,促进细胞凋亡。     

光敏化促进姜黄素诱导人胃癌MGC-803细胞凋亡

目的: 探讨光敏化促进姜黄素诱导人胃癌MGC-803细胞凋亡及其机制。方法: 用MTT法检测光敏化姜黄素对胃癌MGC-803细胞株的增殖抑制率,Hoechst 33258荧光染色观察细胞核形态的变化,流式细胞术检测细胞的凋亡率、线粒体膜电位、细胞内活性氧和Ca²⁺;比色法检测caspase-3、8和9酶活性;Western blotting分析细胞色素C、Bcl-2、Bax和热休克蛋白70(HSP70)水平。结果: 单纯姜黄素(5.0μmol/L)对MGC-803细胞增殖抑制率为(29.74±2.30)%,在光学显微镜下可见部分凋亡细胞,凋亡率为(12.54±1.75)%。而光敏化姜黄素组细胞增殖抑制率则为(44.93±3.61)%,在光学显微镜下能见明显细胞核形态改变,染色质凝集,凋亡小体形成,凋亡率为(26.58±2.67)%,细胞周期主要阻滞于G₀/G₁期。光敏化姜黄素显著降低线粒体膜电位,显著增加细胞色素C、细胞内活性氧和Ca²⁺以及caspase-3、8和9酶活性,与单纯姜黄素组比较,差异显著(P<0.01)。Western blotting结果显示光敏化姜黄素同时显著抑制Bcl-2和HSP70蛋白表达水平。结论: 光敏化姜黄素通过Bcl-2和线粒体途径增强其诱导胃癌MGC-803细胞凋亡的作用。     

辛伐他汀抑制胎牛血清及PDGF-BB诱导的血管平滑肌细胞增殖及对抑癌基因PTEN表达的影响

目的:观察辛伐他汀(simvastatin)对血清及血小板源生长因子(PDGF-BB)诱导的血管平滑肌细胞(VSMCs)增殖的抑制作用及simvastatin对细胞周期和G₁/S周期转换重要调节基因PTEN蛋白表达的影响。方法:[³H]-胸腺嘧啶核苷酸掺入测定VSMCsDNA合成,流式细胞仪检测细胞周期情况,Western印迹杂交法检测PTEN蛋白表达。结果:Simvastatin以剂量依赖关系抑制血清及PDGF-BB诱导的VSMCs[³H]-胸腺嘧啶核苷酸掺入,使G₀/G₁期细胞比例明显增多,S期细胞比例显著减少,并上调PTEN蛋白表达,而3羟3甲戊二酰辅酶A代谢产物甲羟戊酸能抑制simvastatin上调PTEN的表达。结论:Simvastatin抑制血清及PDGF-BB诱导的VSMCs增殖阻滞细胞周期可能与上调PTEN表达有关,且simvastatin调节PTEN的表达可能通过抑制甲羟戊酸的合成而实现。     

miR-140在人胃癌组织中的表达及对SGC-7901胃癌细胞功能的影响

 目的: 研究microRNA-140(miR-140)在人胃癌和正常胃组织中的表达水平,以及调控miR-140表达后对SGC-7901胃癌细胞功能的影响。方法: 采用实时荧光定量PCR检测miR-140在人胃癌和正常胃组织中的表达水平;将miR-140 mimics(miR-140上调表达)和miR-140 inhibitors(miR-140下调表达)分别通过脂质体转染至人胃癌SGC-7901细胞中,同时设置未转染对照组(control组)和miRNA无义序列转染对照组(NC组)。实时荧光定量PCR检测转染后各组细胞中miR-140的表达变化;MTT方法检测各组细胞的生长活力和顺铂(DDP)作用下的生长抑制率;流式细胞术检测各组的细胞周期和凋亡率;Transwell实验检测各组细胞侵袭能力;Western blot检测各组细胞中组蛋白脱乙酰酶4(HDAC4)蛋白表达。结果: miR-140在人胃癌组织中表达水平显著低于正常胃组织(P<0.05)。与control和NC组相比,miR-140 mimics组中SGC-7901细胞活力和侵袭能力下降,细胞周期被阻滞,DDP作用下细胞生长抑制率和凋亡率上升,且HDAC4蛋白表达下调,差异均有统计学意义(P<0.05);而miR-140 inhibitors组中SGC-7901细胞活力和侵袭能力上升,细胞周期被促进,DDP作用下细胞生长抑制率和凋亡率下降,且HDAC4蛋白表达上调,差异均有统计学意义(P<0.05)。结论: miR-140在胃癌组织中低表达,可作为抑癌因子调控胃癌细胞活力、细胞周期变化、凋亡、侵袭并通过下调HDAC4发挥作用。miR-140可能作为胃癌诊断和治疗的新靶点。     

MicroRNA-106a functions as an oncogene in human gastric cancer and contributes to proliferation and metastasis in vitro and in vivo

Mounting evidences has shown that miRNAs are involved in the development and progression of gastric cancer acts as tumor suppressor genes or oncogenes. In our previous studies, we have found that the up-regulation of miR-106a occurs frequently in human gastric cancer tissues compared with that of normal tissues. Here, we investigate the role of the ectopic expressed miR-106a in the progression and metastasis of gastric cancer in vitro and in vivo. FFPE samples have the priority to be included and qRT-PCR was used to detect the miR-106a expression. Human gastric cancer cells and immortalized gastric epithelial cell were selected and the miR-106a mimic and inhibitor were transfected. Cell growth was determined by MTT method. The flow cytometric analysis for cell apoptosis and transwell assays for evaluating the cell migration and invasion were conducted. Luciferase assay and western blot confirmed the direct binding site of miR-106a and its target. BALB/c nude mice were randomly divided to explore the implantation of gastric cancer cells transfected with miR-106a antagomir. Abnormal over-expression of miR-106a significantly promoted gastric cancer cell proliferation, metastasis, inhibited the cell apoptosis. Functional experiment ascertained that miR-106a interacted with FAS and mediated caspase3 pathway. Knockdown of miR-106a leaded to the attenuation of gastric cancer implantation capacity in vivo. Moreover, expression of TIMP2 was inversely associated with miR-106a in nodule tissues. Apoptotic body was also seen under electron microscope accompanied by silencing of miR-106a. Together, this data indicated that miR-106a may act as an oncogene and contribute to gastric cancer development.     

MiRNA-429 suppresses the growth of gastric cancer cells in vitro

Micro-RNAs(miRNAs) have been found to be implicated in a very wide range of physiological processes.This study was aimed to investigate the regulation of miRNA-429(miR-429) in gastric cancer cells on cell proliferation and apoptosis.Quantitative PCR was employed to detect the expressions of miR-429 after eukaryotic expression plasmid of miR-429 and its inhibitor were transiently transfected into poorly differentiated human gastric can-cer cell line BGC823.The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) reduction as-says were used to examine proliferation ability.Apoptosis was analyzed by flow cytometry after transfection.The results showed that 48 h after transfection,overexpression of miR-429 reached maximum efficiency.Compared with mock transfection,miR-429 inhibited tumor cell proliferation significantly(P < 0.05) at 48 h and 72 h.of Overexpression of miR-429 promoted tumor cell apoptosis when compared with mock transfected cells(P < 0.05).On the contrary,miR-429 inhibitor promoted tumor cell proliferation and inhibited apoptosis when compared with controls(P < 0.05).Our results suggested that miRNA-429 may serve as a tumor suppressor during tumorigenesis of gastric cancer and may be a potential gastric cancer therapeutic target.     

Diagnostic significance of miR-106a in gastric cancer

As one of the most common malignant tumors, gastric cancer still lacks tumor markers with enough specificity and sensitivity. Therefore the development of novel tumor markers is necessary for early diagnosis in clinics. MicroRNA (miR) has been known to be of unique expressional patterns in various tumors and may work as potential tumor markers for clinical use. This study thus explored the significance of plasma miR-106a in clinical diagnosis of gastric cancer and its effects on proliferation of cancer cells. Plasma miR-106a levels were quantified by real-time quantitative fluorescent PCR methods in 80 cases of gastric cancer patients and healthy individuals to analyze the correlation between miR-106a and clinical features. MiR-106 inhibitor was further transfected into human gastric carcinoma cells for further cell proliferation using CCK-8 approach. MiR-106a was significantly up-regulated in gastric cancer patient plasma samples compared to healthy individuals (P<0.01). The area under ROC curve was 0.895 (95% CI: 0.846~0.943). It has a specificity of 93.8% and a sensitivity of 77.5% in diagnosing gastric cancer. MiR-106a level was also correlated with cancer differentiation stage, lymph node metastasis, TNM stage and tumor size (P<0.05). The down-regulation of miR-106 in gastric carcinoma cells inhibited cell proliferation (P<0.05). MiR-106a was significantly up-regulated in gastric cancer patients and can facilitate the in vitro proliferation of tumor cells. It may work as a biological marker for gastric cancer.     

胃癌下调新基因CA11表达产物的组织分布和细胞定位

目的 筛选胃癌下调基因，确定其表达产物的组织分布和细胞定位。方法 从已成功建立的5人份正常胃粘膜mRNA(Tester)抑制消减杂交胃癌mRNA(Driver)的差异表达文库，随机挑取阳性克隆测序为CA11，RT－PCR证实其为下调基因。地高辛标记CA11原位mRNA杂交。在其它组织器官中扩增化基因，以表明其组织分布特异性。CA11克隆至载体pcDNA3.1/Myc-His(-)A中，并瞬时转染CA11的COS－7细胞。生长至对数生长期时，吸取培养液，Talon吸附，洗脱后，取洗脱液进行SDS蛋白电泳及Western blot。CA11转染COS－7细胞后加抗Myc标签的一抗，最后加FITC标记的二抗在荧光显微镜下观察。结果 筛选到胃癌下调基因CA11，并经RT－PCR证实。mRNA原位杂交显示，CA11位于胃粘膜上皮细胞。在其它组织器官cDNA文库及组织RNA中均未扩增出该基因。洗脱液W estern blot未检测到CA11与pcDNA3.1/Myc-His(-)A的Myc融合表达蛋白存在；CA11表达蛋白亚细胞定位于细胞浆。结论 CA11为一胃癌下调基因，它在胃粘膜上皮细胞特异表达，表达产物的位于细胞浆。     

miRNA-326调控胃癌细胞活力和凋亡的机制及其在胃癌组织中的表达及临床意义

目的:探讨微小RNA-326(miRNA-326)调控胃癌细胞活力和凋亡的机制及其在胃癌组织中的表达及临床意义。方法:采用RT-qPCR检测miRNA-326在55例胃癌组织中的表达情况,并分析其与临床病理特征的关系。以胃癌细胞BGC-823为研究对象,RT-qPCR检测miRNA-326在细胞中的表达;将BGC-823细胞随机分为正常对照组(未转染)、mimic-NC组(转染mimic阴性对照)和miRNA-326 mimic组(转染miRNA-326 mimic),以脂质体转染法上调miRNA-326表达后,CCK-8法检测细胞活力,流式细胞术检测细胞凋亡,Western blot检测基质金属蛋白酶9(MMP-9)、p21、细胞周期蛋白D1(cyclin D1)、Bcl-2和cleaved caspase-3的蛋白水平,RT-qPCR检测cyclin D1的mRNA表达,双萤光素酶报告基因检测法验证CCND1 (cyclin D1的基因)是否是miRNA-326的靶基因。结果:miRNA-326在胃癌组织中的表达明显低于癌旁组织(P 0. 05),其表达与肿瘤大小、淋巴结转移、分化程度及临床分期均有显著相关性(P 0. 05),而与患者的年龄和性别无关;此外,还与患者生存率密切相关(P 0. 05)。miRNA-326在BGC-823细胞中的表达明显低于正常胃黏膜GES-1细胞(P 0. 05)。与正常对照组相比,mimic-NC组细胞中miRNA-326的表达无明显变化,而miRNA-326 mimic组细胞中miRNA-326的表达明显升高(P 0. 05)。与正常对照组相比,miRNA-326 mimic组细胞活力明显减弱,而细胞凋亡增强(P 0. 05);此外,与正常对照组相比,miRNA-326 mimic组细胞中MMP-9、cyclin D1、Bcl-2蛋白及cyclin D1 mRNA表达下降,而p21和cleaved caspase-3的蛋白水平上升(P 0. 05)。然而,mimic-NC组与正常对照组相比,各检测指标的差异均无统计学显著性。与mimic-NC+miR-326 mimics组相比,转染pmiR-CCND1-WT质粒细胞的萤光素酶活性降低(P 0. 05),而转染pmiRCCND1-Mut质粒的萤光素酶活性无改变。结论:miRNA-326在胃癌组织中低表达,可能通过靶向调控CCND1表达而促进细胞活力并抑制细胞凋亡。     

A method for the isolation of human gastric mucous epithelial cells for primary cell culture: A comparison of biopsy vs surgical tissue

We have developed a method for the isolation and growth of normal human gastric mucous epithelial cells using biopsies or surgically resected tissues as the source of the cells. The attachment and growth of cells were dependent upon: (1) cell planting density, 50,000 cells/cm²; (2) extracellular matrix (fibronectin); and (3) and the use of a porous filter. In all experiments we found better cells attachment and growth of human gastric mucous cells isolated from surgical specimens compared with those gastric mucous cells isolated from gastric biopsies. The initial cell viability (as measured by Trypan-blue) was the same in both populations of gastric mucous epithelial cells isolated from either gastric biopsies or surgical specimens. After 4–5 days in culture one could detect various amounts of mucin in all the cells using either periodic acid Schiff (PAS) staining or a specific anti-mucin antibody. A similar pattern of much straining was also found in primary cultures of guinea pig gastric mucous epithelial cells. Immunohistochemical staining for chief cells (anti-pepsinogen) or parietal cells (anti-H⁺/K⁺ ATPasc) in the gastric mucous cuboidal-like epithelial cells with tight junctions, desmosomes,short microvilli, a filamentous terminal web, mucous granules, and basal lamina-like structure. We could not detect the presence of fibroblasts during the 7–9 days that the primary cells were in culture. This cell culture method will prove useful in the isolation of normal human gastric mucous epithelial cells for in vitro studies of gastric mucosal injury and repair.     

MicroRNA-125b在胃癌组织中的高表达并促进胃癌细胞系HGC-27和MGC-803的增殖

 目的 探讨microRNA-125b (miR-125b)基因在胃癌患者组织中的表达改变情况,及其对胃癌细胞系增殖和凋亡的影响。方法 使用real-time PCR方法检测miR-125b在40例临床诊断为胃癌患者的癌组织与癌旁对照组织中的表达情况。随后使用miR-125b mimic转染胃癌细胞系HGC-27和MGC-803,确认过表达成功后,分别使用CCK-8试剂盒和流式细胞仪检测过表达miR-125b对细胞增殖和凋亡的影响。结果 证实在胃癌患者组织中miR-125b的表达水平显著高于癌旁对照组（P<0.01）。在胃癌细胞系HGC-27和MGC-803中过表达miR-125b后,细胞增殖明显增加：转染72h,HGC-27（scramble组：1.632±0.09,mimic组：2.473±0.08）,MGC-803（scramble组：1.603±0.05,mimic组：2.554±0.07））,同时细胞凋亡也受到抑制。结论 miR-125b可能作为癌基因在胃癌中发挥作用,并对细胞增殖和凋亡具有显著影响。     

miR-1246增强宫颈癌细胞辐射敏感性的分子机制研究

目的:探讨微小RNA-1246(miR-1246)过表达增强宫颈癌细胞放疗敏感性的分子机制。方法:运用脂质体2000将miR-1246模拟物(miR-1246 mimic)转染4种宫颈癌细胞系He La、Ca Ski、C33A和Si Ha,以阴性对照模拟物(NC-mimic)为阴性对照。Real-time PCR检测宫颈癌组织、正常组织、子宫内膜上皮细胞系ESC和4株宫颈癌细胞中miR-1246的表达水平;转染的细胞经电离辐射照射后运用MTT法和Transwell法分别测定细胞活力和细胞迁移能力;运用免疫荧光法检测γH2AX表达水平;Western blot检测细胞中γH2AX、ATM、p-ATM和p-p53的蛋白水平。结果:miR-1246在正常组织和ESC细胞中高表达,而在4株宫颈癌细胞和宫颈癌组织中低表达;转染miR-1246 mimic后miR-1246表达水平显著高于NC-mimic组细胞(P 0. 05)。相同条件下,辐照后miR-1246过表达组宫颈癌细胞活力显著低于NC-mimic组,细胞迁移率明显降低(P 0. 05)。免疫荧光结果显示,miR-1246过表达显著增强电离辐射诱导的γH2AX激活(P 0. 05);Western blot结果显示,与NC-mimic组比较,miR-1246过表达显著促进电离辐射诱导γH2AX蛋白的表达,减低p-ATM和p-p53的蛋白水平(P 0. 05)。结论:miR-1246在正常组织和子宫内膜上皮细胞中高表达,而在宫颈癌组织和宫颈癌细胞系中低表达;miR-1246过表达抑制宫颈癌细胞活力和迁移能力,并可能通过阻断ATM通路、抑制DNA损伤修复而增强宫颈癌细胞的辐射敏感性。