RNA干扰hTERT基因治疗喉鳞状细胞癌的实验研究

目的:探讨RNA干扰hTERT(人端粒酶逆转录酶)基因对人喉鳞状细胞癌的治疗作用.方法:根据hTERT cDNA序列构建表达hTERT mRNA特异的、含荧光素基因的shRNA真核表达质粒pshRNA1、pshRNA2.将shRNA质粒分别转染人喉癌Hep-2细胞株及荷瘤裸鼠瘤体内.以激光共聚焦显微镜观察质粒在Hep-2细胞及瘤体内的表达;以MTT法观察质粒对Hep-2细胞增殖的抑制作用;以蛋白印迹法(Western blot法)检测Hep-2细胞中hTERT蛋白的表达;以免疫组化SP法检测裸鼠瘤体内hTERT蛋白的表达.结果:pshRNA1、pshRNA2转染Hep-2细胞及pshRNA1转染瘤体后,共聚焦显微镜下见大量的癌细胞表达绿色荧光,hTERT蛋白表达明显下降.细胞受pshRNA1、pshRNA2转染后,其生长活性受到明显抑制.体内抑瘤实验表明,与空质粒载体组(pshRNA4)和生理盐水组相比,pshRNA1组移植瘤生长明显受到抑制.结论:表达shRNA的、hTERT基因特异的真核表达质粒能有效转染体内、外喉鳞癌细胞,并可有效抑制人喉鳞癌细胞的生长,为今后应用RNA干扰基因治疗喉癌提供重要的实验参考.     

RNA干扰抑制Hep-2细胞人端粒酶逆转录酶基因表达对放射敏感性的影响

目的构建人端粒酶逆转录酶(hTERT)基因特异性短发夹样RNA(shRNA)真核表达载体,观察其联合射线对人喉癌Hep-2细胞端粒酶活性和细胞存活的影响,研究hTERT基因在放射增敏中的作用。方法根据hTERT mRNA编码序列设计RNA干扰(RNAi)靶点,构建重组表达质粒pshRNA-hTERT,构建成功后,转染Hep-2细胞并作射线处理,用端粒重复序列扩增方法(TRAP-PCR- EHSA)检测端粒酶活性的动态变化,采用克隆形成分析方法观察质粒pshRNA-hTERT对Hep-2细胞放射敏感性的影响,计算放射增敏比SER_(SF2)。结果转染质粒pshRNA-hTERT后,Hep-2细胞的hTERT mRNA表达抑制率为60.8%,质粒pshRNA-hTERT不仅能够抑制Hep-2细胞的端粒酶活性(P<0.05),而且还可以抑制辐射诱导的端粒酶活性上升(P<0.05)。照射前经pshRNA-hTERT处理24h,明显降低了2Gy照射后Hep-2细胞的存活分数(85.7%),与单纯放射组(67.7%)相比,差异有统计学意义(P<0.05),pshRNA-hTERT的放射增敏比SER~(SF2)为1.27。结论RNAi显著抑制了靶基因hTERT的表达,质粒pshRNA-hTERT能明显抑制2Gy照射诱导的Hep-2细胞端粒酶活性升高,并显著提高其体外放射敏感性;质粒pshRNA-hTERT的放射增敏作用可能与端粒酶活性受抑制有关。     

hTERT 短发夹状RNA 抑制前列腺癌细胞生长的研究

 目的 研究靶向端粒酶逆转录酶（hTERT）的短发夹状RNA（shRNA）基因转染对前列腺癌细胞体外生长的抑制效应及其促细胞凋亡作用。方法 在脂质体介导下将针对hTERT基因的shRNA表达载体psilencer-TRT转染前列腺癌细胞PC-3m，得到稳定细胞株PC-3m／shRNA-TRT。采用RT-PCR检测hTERT基因表迭情况，western blot分析各组细胞hTERT及c-myc蛋白表达变化，细胞计数并绘制细胞生长曲线，Hoechst33258染色、透射电镜、流式细胞仪检测细胞凋亡情况。结果 重组质粒psilencer-TRT转录生成的shRNA使实验组细胞的hTERT基因表达显著下调，抑制率约为89．02％；同时实验组细胞hTERT及c-myc蛋白水平较对照组有明显下降，细胞的生长增殖能力也显著降低（P〈0．05），生长速率明显变慢，部分细胞呈现凋亡形态学改变，凋亡率为（19．69±4．75）％。结论 hTERT短发夹状RNA能有效抑制前列腺癌细胞中hTERT表达及癌细胞生长，诱导PC-3m细胞凋亡，可望为前列腺癌的基因治疗提供新方法。     

shRNA-targeted hTERT suppress cell proliferation of bladder cancer by inhibiting telomerase activity

RNA interference (RNAi) has demonstrated profound prospect in human gene research. hTERT, the rate-limiting component of telomerase activity, is highly expressed in bladder cancer cells. Here, we investigated the anti-proliferation effects of small hairpin interfering RNA (shRNA)-targeted hTERT gene on bladder cancer in vitro and in vivo. The results showed that ph2-shRNA, the most-effective vector carrying shRNA-targeted hTERT, could significantly inhibit the cell proliferation by down-regulating hTERT expression, decreasing telomerase activity, decreasing cell number of S phase, increasing the cell number of G0/G1 phase in T24 cells and xenograft tumor tissues, and attenuate the tumor growth of xenograft mice model compared with controls. Our results demonstrate that hTERT-directed shRNAs are potent inhibitors of bladder cancer. Lin Zou and Penghui Zhang were equally contributed to this paper.     

RNA干扰靶向抑制胃癌细胞株SGC7901 hTERT基因表达

背景与目的：胃癌是全人类常见恶性肿瘤之一。在我国，胃癌居各种癌症死亡之首，其总体五年生存率仅15％～20％。在目前尚无有效一级预防措施的情况下，积极探讨有效防治胃癌的方法成为必然趋势。本研究利用RNA干扰稳定筛选-抑制技术，抑制人端粒酶逆转录酶（hTERT）基因表达，探讨靶向hTERT基因RNAi对胃癌细胞增殖的抑制效应。方法：设计靶向hTERT基因的小干扰RNA，构建重组表达质粒pGenesil—shRNA—hTERT并导入人胃癌细胞系SGC7901细胞株，经G418筛选，建立稳定表达siRNA—hTERT的细胞株。采用real time RT—PCR、MTT和PCR—TRAP法同时检测pGenesil-shRNA—hTERT稳定抑制组和未处理SGC7901细胞组hTERT基因表达、端粒酶活性及细胞增殖变化。结果：在稳定表达pGenesil—shRNA—hTERT的SGC7901细胞株中，RNAi效力持续、稳定存在，hTERT mRNA表达、端粒酶活性明显降低，瘤细胞增殖被抑制。结论：RNA干扰能持续、稳定地抑制靶基因hTERT mRNA表达及肿瘤细胞增殖，是潜在的肿瘤基因治疗新方法。     

腺病毒介导的shRNA沉默hTERT基因表达对鼻咽癌细胞增殖和凋亡的影响

目的探讨靶向人端粒酶反转录酶（hTERT)的短发夹RNA（shRNA)对人鼻咽癌细胞株CNE-2 hTERT表达的影响,及其对鼻咽癌细胞增殖和凋亡的效应。方法构建表达绿色荧光蛋白(EGFP)基因和靶向hTERT基因短发夹RNA的重组腺病毒质粒,观察其对鼻咽癌细胞株(CNE-2)的转染效果,RT-PCR检测hTERT mRNA表达水平,Western blot检测hTERT蛋白表达水平,CCK-8法检测细胞增殖活性,流式细胞仪检测细胞凋亡状况。结果Adv-EGFP-shTERT重组腺病毒质粒转染率可达90%以上,成功转染CNE-2细胞24 h后,hTERT mRNA的表达水平显著下降,转染48 h后,hTERT蛋白表达明显下调,细胞增殖活性受到显著抑制,细胞凋亡率可达23.0%。结论腺病毒载体介导靶向hTERT基因的RNA干扰,能显著抑制端粒酶反转录酶表达,进而抑制端粒酶活性,抑制CNE-2细胞增殖并诱导其凋亡,为鼻咽癌的基因治疗研究提供了理论基础。     

人端粒酶催化亚基反义核酸对子宫内膜癌细胞的抑制作用

目的 探讨人端粒酶催化亚基(hTERT)基因反义寡核苷酸(AODN)对子宫内膜癌细胞系HEC-1A的生长抑制作用及作用机理。方法 采用四甲基偶氮唑蓝(MTT)法检测AODN对细胞增殖能力及细胞生长的影响;逆转录聚合酶链反应技术(RT-PCR)、定量端粒酶重复扩增法(TRAP)、Westerm blot蛋白免疫印迹法和凋亡相关酶活性测定检测反义核酸对hTERT基因转录、蛋白表达、细胞端粒酶活性以及凋亡相关酶活性的变化。结果 低浓度hTERT基因AODN能够下调HEC-1A细胞HTERT、mRNA含量,抑制细胞hTERT蛋白表达,下调端粒酶活性,并且激活凋亡相关酶Caspase-1和Caspase-3活性;其对细胞的生长抑制作用有明显的时效性和剂量依赖性。结论 hTERT基冈反义核酸能够抑制子宫内膜癌细胞的增殖能力,有望成为内膜癌治疗的新方向。     

Hexokinase 2 overexpression promotes the proliferation and survival of laryngeal squamous cell carcinoma

Proliferating cancer cells preferentially use anaerobic glycolysis rather than oxidative phosphorylation for energy production. Hexokinase 2 (HK2) is highly expressed in many malignant cells and is necessary for anaerobic glycolysis. The role of HK2 in laryngeal squamous cell carcinoma (LSCC) is unknown. In this study, the expression of HK2 in LSCC was investigated and the effect of inhibiting HK2 expression with small hairpin RNA (shRNA) on tumor growth was investigated. Using immunohistochemistry, HK2 expression was assessed in LSCC tissues. Human laryngeal carcinoma Hep-2 cells were stably transfected with a plasmid expressing HK2 shRNA (pGenesil-1.1-HK2) and were compared to control cells with respect to the cell cycle, cell viability, apoptosis, and their ability to form xenograft tumors. HK2 expression was significantly higher in LSCC than in papilloma or glottis polypus. Tumor samples of higher T, N, and TNM stage often had stronger HK2 staining. HK2 shRNA reduced HK2 mRNA, protein levels, and HK activity in Hep-2 cells. HK2 cells expressing shRNA demonstrated a higher G0–G1 ratio, increased apoptosis, and reduced viability. Xenograft tumors derived from cells expressing HK2 shRNA were smaller and had lower proliferation than those from untransfected or control-plasmid-transfected cells. In conclusion, depletion of HK2 expression resulted in reduced xenograft tumor development likely by reducing proliferation, altering the cell cycle, reducing cell viability and activating apoptosis. These data suggest that HK2 plays an important role in the development of LSCC and represents a potential therapeutic target for LSCC.     

RNA干扰对肾癌细胞端粒酶活性及增殖、凋亡的影响

目的 探讨针对人端粒酶RNA（hTR）及其催化亚基（hTERT）的小干扰RNA（siRNA）对肾癌细胞端粒酶活性及其增殖、凋亡的影响。方法 将hTR-siRNA、hTERT-siRNA（100nmol／L）单独或联合转染人肾癌786—0细胞,采用RT-PCR法检测hTR、hTERT mRNA表达,TRAP-ELISA法检测端粒酶活性,MTT法检测细胞增殖,免疫组化TUNEL法检测细胞凋亡。结果 （1）hTR-siRNA可显著降低786—0细胞hTR mRNA表达（P〈0．01）,hTERT-siRNA可显著降低hTERT mRNA表达（P〈0．01）,但彼此互不影响。（2）二者均能显著抑制端粒酶活性（P〈0．01,P〈0．01）,并增加786—0细胞增殖抑制率及凋亡细胞阳性率（P〈0．01,P〈0．01）。二者联合应用与单独应用差异亦无显著性（P〉0．05）。结论 hTR、hTERT siRNA通过抑制各自基因表达,抑制人肾癌细胞端粒酶活性,进而抑制增殖、促进凋亡。