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.     

下调miR-183靶向肿瘤抑制因子CPEB1增强脑胶质瘤细胞的 放射敏感性

目的：探讨 miR-183 对脑胶质瘤细胞放射敏感性的影响。方法：2020 年 10 月至 2021 年 6 月,收集秦皇岛市第一医院 40 例脑胶质瘤组织标本,对 T98G 细胞进行梯度剂量 X 射线（0、2、4、6 Gy）照射。采用 qPCR 检测 miR-183、细胞质多腺苷酸化元件结合蛋白 1（cytoplasmic polyadenylation element-binding protein 1,CPEB1）在脑胶质瘤组织、T98G 细胞和经 X 射线照射的 T98G 细胞中的表达量。将 miR-183 inhibitor 转染 T98G 细胞后下调 miR-183 表达,经 6 Gy X 射线垂直照射,CCK-8 法、流式细胞术和 WB 法,分别检测 T98G 细胞增殖能力、细胞凋亡率及 BAX 和 Bcl2 蛋白表达量。Targetscan 软件预测和双荧光素酶报告基因实验检测 miR-183 与 CPEB1 的靶向关系。下调 CPEB1 表达后,经 6 Gy X 射线照射,分别用 CCK-8 法、流式细胞术和 WB 法检测 T98G 细胞增殖能力、细胞凋亡率及 BAX 和 Bcl2 蛋白表达量。将 pcDNA-CPEB1 或 CPEB1 siRNA 质粒转染T98G 细胞,分别下调或过表达 CPEB1 后,检测 miR-183 通过 CPEB1 对 T98G 细胞放射敏感性的影响。结果：脑胶质瘤组织和细胞中 miR-183 呈高表达,CPEB1 mRNA 呈低表达。T98G 细胞中 miR-183 的表达量随着 X 射线放射剂量增加而降低（P<0.05）,CPEB1 表达量随着 X 射线放射剂量增加而升高（P<0.05）。6 Gy X 射线照射 T98G 细胞后,下调 miR-183 可降低细胞增殖能力、增加细胞凋亡率,而过表达 miR-183 则起到相反作用（P<0.05）。miR-183 靶向 CPEB1 mRNA 且负调控 CPEB1 表达。下调 CPEB1 表达后,经 6 Gy X 射线照射可显著提高 T98G 细胞增殖能力（P<0.05）、降低细胞凋亡率（P<0.05）,miR-183 可逆转 CPEB1 过表达对细胞 T98G 放射敏感性的促进作用（P<0.05）。结论：下调 miR-183 的表达能够负调控 CPEB1,从而增强脑胶质瘤细胞的放射敏感性。     

Interferon-alpha repressed telomerase along with G1-accumulation of Daudi cells.

The implications of telomerase on senescence and human carcinogenesis are widely accepted, but the changes of telomerase activity along with cell cycle modulation by anticancer treatment still remain obscure. In this paper, we issued whether the telomerase activity fluctuated along with cell cycle of cultured cancer cells using the antiproliferative effect of interferon-alpha (IFN-alpha). Daudi Burkitt lymphoma cells, treated with IFN-alpha, showed proliferation inhibition and cell cycle arrest at G1. The telomerase activity at 72 h was repressed to about 20% of control cells. Furthermore, after 72 h IFN-alpha treatment, the cells in G1 phase showed the marked decrease of telomerase activity, while cells in S and G2/M still possessed it. Among expressions of telomerase-related genes, only the catalytic subunit of telomerase (hTERT) decreased from 48 h, while the template RNA component (hTERC) and telomerase-associated protein 1 (TEP-1) were not affected. The downregulation of c-Myc preceded the change of hTERT. Moreover, the analysis of cells treated with IFN-alpha for 24 h revealed that cells in G1-to-S transition mainly expressed high hTERT, while S and G2/M cells had higher level of telomerase activity than that of G1 cells. These results indicate that (i) the expression of hTERT precedes the telomerase activity which is higher in S and G2/M phases than G1 phase, (ii) IFN-alpha repressed the telomerase activity in a cell cycle-dependent manner with the downregulation of hTERT.     

蟾蜍灵通过抑制端粒酶活性诱导人脑胶质瘤细胞死亡

目的:探讨蟾蜍灵对人脑胶质瘤的作用。方法:将不同浓度的蟾蜍灵作用于胶质瘤细胞后,用CCK-8法检测细胞增殖抑制率,克隆形成实验检测细胞法检测增殖抑制,Western-blot测定人端粒酶逆转录酶（hTERT）的蛋白表达,Real time-PCR检测hTERT基因表达水平,CCK-8法检测蟾蜍灵对人原代胶质瘤细胞的杀伤作用。结果:蟾蜍灵对胶质瘤细胞株细胞U251、U87增殖具有抑制作用,且呈时间和剂量依赖性,并且能够有效抑制U251及U87细胞的克隆形成。Western-blot结果显示hTERT蛋白表达随药物浓度增加而递减,Real time-PCR结果证实蟾蜍灵降低了hTERT基因表达。同时体外实验证明,蟾蜍灵对人原代胶质瘤细胞具有明显杀伤作用。结论:蟾蜍灵能够抑制胶质瘤细胞系细胞及人原代胶质瘤细胞增殖,同时通过抑制hTERT表达降低端粒酶活性以发挥其抗肿瘤的作用。     

hTERT反义寡核苷酸对HL-60细胞凋亡及细胞周期的影响

目的：研究hTERT基因反义寡核苷酸（ASODN）对HL-60细胞诱导凋亡作用及细胞周期的影响.方法：应用hTERT ASODN封闭HL-60细胞hTERT基因,RT-PCR方法检测目的基因的表达;流式细胞仪检测细胞凋亡及细胞周期分析,TUNEL方法检测细胞凋亡,琼脂糖凝胶电泳检测凋亡细胞DNA梯带.结果：hTERT ASODN作用细胞72h后,hTERT基因表达明显受到抑制（P＜0.01）.流式细胞仪检测显示：ASODN组细胞阻滞于G0/G1期,S、G2/M期细胞减少（P＜0.05）;细胞增殖指数（PI）明显降低（P＜0.05）;检测出早期凋亡峰.Annexin V/PI检测及TUNEL检测均显示：ASODN组凋亡细胞阳性率明显高于SODN组（P＜0.01）.琼脂糖凝胶电泳显示：ASODN组出现凋亡DNA梯带.结论：hTERT ASODN能够封闭目的基因表达,阻滞HL-60细胞于G0/G1期,并诱导细胞凋亡,对治疗白血病具有潜在应用价值.     

反义寡核苷酸对K562细胞增殖和端粒酶活性的影响

 目的　研究靶向封闭端粒酶反转录酶（hTERT）mRNA的反义硫代寡核苷酸（ASPSODN）对K562细胞目的基因的抑制及其对端粒酶活性及细胞增殖周期和凋亡的影响 。方法　ASPSODN转染到人类红白血病细胞株K562,采用MTT法、酶联免疫吸附（ELISA）法和流式细胞术（FCM）检测K562细胞的增殖、端粒酶活性、细胞凋亡和细胞周期的改变,RT-PCR检测hTERT mRNA的表达。结果　0.6 μmol／L的ASPSODN（0.42±0.16）能明显下调hTERT表达（P＜0.05）,端粒酶相对活性降至52 %;MTT法检测显示明显抑制K562细胞增殖活性;FCM显示细胞凋亡率为10.31 %,PI染色显示细胞被阻止在G1／G0期,S期及G2／M期的细胞减少,但无特征性的凋亡峰。结论　ASPSODN靶向 hTERT 能特异性抑制K562细胞hTERT mRNA的表达,明显下调端粒酶活性,抑制K562细胞增殖,并通过降低细胞的端粒酶活性而诱发细胞凋亡。     

Effect of plasmid-mediated RNA interference targeting telomerase reverse transcriptase on lung cancer cells

In the present study, a plasmid-mediated siRNA interference vector targeting the hTERT gene was constructed and stably transfected into H1299 lung cancer cells. Using real-time quantitative fluorescent PCR technology, western blotting and flow cytometry-based cell cycle profiling, the silencing effect of this vector and its inhibitory effect on proliferation in lung cancer cells were explored. Based upon the results of our previous study, a pair of siRNA sequences was selected, and a DNA template primer was designed and synthesized. After cloning of the template primer into the promoter of the pGenesil-1.1 expression vector, the constructed interference vector was validated using enzyme digestion and gene sequencing. The recombinant interference vector and empty vector were separately transfected into H1299 lung cancer cells with cationic liposomes, and stable monoclonally transfected cells were obtained after selection with G418. After stable transfection, hTERT mRNA and protein expression levels were detected using real-time RT-PCR technology and western blotting. Using the MTT method and a colony formation assay, the growth and proliferation of the stably transfected lung cancer cells were determined. Changes in the cell cycle profile of the stably transfected lung cancer cells were detected using flow cytometry. An interference vector targeting the hTERT gene (pGenesil.1-hTERT) was successfully constructed. Enzyme digestion and gene sequencing confirmed that the sequence insertion met the criteria of the design. After transfection of H1299 cells with pGenesil.1-hTERT or an empty vector, the stably transfected monoclonal cell lines H1299-pGenesil.1-hTERT and H1299-pGenesil.1 were obtained. Compared to the control cells transfected with the empty vector, the H1299-pGenesil.1-hTERT cells had significantly lower mRNA expression of hTERT (93.97±0.83% inhibition, with P<0.001). The protein expression of hTERT in H1299-pGenesil.1-hTERT cells was significantly lower compared to that in H1299-pGenesil.1 cells. The rate of proliferation of H1299-pGenesil.1-hTERT cells was lower compared to that of H1299-pGenesil.1 lung cancer cells. In H1299-pGenesil.1-hTERT cells, the number of cells in the G1 phase increased by 18.3% (P<0.05) compared to the control group; the number of cells in the S and G2 phases decreased by 10.4 and 7.9%, respectively (P<0.05). A recombinant plasmid that interfered with the expression of the hTERT target gene was successfully constructed. Upon transfection of the recombinant interference plasmid into H1299 lung cancer cells, hTERT mRNA and protein expression were down-regulated effectively, telomerase activity and cell proliferation were inhibited, and the cell cycle profile was altered.     

反义hTERT对K562细胞端粒酶活性及细胞增生的影响

目的：观察反义hTERT表达质粒转染K562细胞后是否能够抑制端粒酶活性及K562细胞的增生。方法：质粒的构建与转染；将200bphTERTcDNA片段，反向连接于pLNCX-neo质粒上得到反义hTERT基因表达质粒，在体外转染中通过脂质体法将质粒导入K562细胞中，以G418进行筛选得到阳性克隆；以MTT法和形态学法检测反义hTERT表达质粒对K562细胞增生的抑制作用；以TRAP-PCRELISA法来研究反义hTERT基因对K562细胞的端粒酶活性的抑制作用。结果：转染反义hTERT表达质粒细胞与对照组（空白对照及空质粒组）相比较。生长速率明显变慢。部分细胞出现凋亡等形态学改变。反义hTERT对K562细胞的端粒酶活性具有明显的抑制作用。结论：研究构建的端粒酶反义hTERT基因表达质粒转染到K562细胞中后，能够封闭K562细胞hTERT-mRNA的表达，在抑制端粒酶活性的同时，减慢了K562细胞的生长速度。     

PinX1 regulation of telomerase activity and apoptosis in nasopharyngeal carcinoma cells

Background

Human interacting protein X1 (PinX1) has been identified as a critical telomerase inhibitor and proposed to be a putative tumor suppressor gene. Loss of PinX1 has been found in a large variety of malignancies, however, its function in inhibiting telomerase activity of tumor cells is not well documented. Here we show that PinX1 is essential for down-regulation telomerase activity of nasopharyngeal carcinoma.

Methods

Expression vectors of human PinX1 (pEGFP-C3-PinX1) and its small interfering RNA (PinX1-FAM-siRNA) were constructed and transfected into NPC. Their effects on mRNA of telomerase catalytic subunit (hTERT), telomerase activity, cell proliferation, cell migration, wound healing, cell cycles and apoptosis were examined using semi-quantitative RT-PCR, stretch PCR, MTT assay, Transwell, scratch assay and flow cytometry, respectively.

Results

Transfection of pEGFP-C3-PinX1 and PinX1-FAM-siRNA increased and reduced PinX1 mRNA by 1.6-fold and 70%, respectively. Over-expression of PinX1 decreased hTERT mRNA by 21%, reduced telomerase activity, inhibited cell growth, migration and wound healing ability, arrested cells in G0/G1 phase, and increased apoptotic index. In contrast, down-regulation of PinX1 did not alter the above characteristics.

Conclusions

PinX1 may play important roles in NPC proliferation, migration and apoptosis and has application potential in tumor-targeted gene therapy.     

Over-expression of BMPR-IB reduces the malignancy of glioblastoma cells by upregulation of p21 and p27Kip1

Background

Human interacting protein X1 (PinX1) has been identified as a critical telomerase inhibitor and proposed to be a putative tumor suppressor gene. Loss of PinX1 has been found in a large variety of malignancies, however, its function in inhibiting telomerase activity of tumor cells is not well documented. Here we show that PinX1 is essential for down-regulation telomerase activity of nasopharyngeal carcinoma.

Methods

Expression vectors of human PinX1 (pEGFP-C3-PinX1) and its small interfering RNA (PinX1-FAM-siRNA) were constructed and transfected into NPC. Their effects on mRNA of telomerase catalytic subunit (hTERT), telomerase activity, cell proliferation, cell migration, wound healing, cell cycles and apoptosis were examined using semi-quantitative RT-PCR, stretch PCR, MTT assay, Transwell, scratch assay and flow cytometry, respectively.

Results

Transfection of pEGFP-C3-PinX1 and PinX1-FAM-siRNA increased and reduced PinX1 mRNA by 1.6-fold and 70%, respectively. Over-expression of PinX1 decreased hTERT mRNA by 21%, reduced telomerase activity, inhibited cell growth, migration and wound healing ability, arrested cells in G0/G1 phase, and increased apoptotic index. In contrast, down-regulation of PinX1 did not alter the above characteristics.

Conclusions

PinX1 may play important roles in NPC proliferation, migration and apoptosis and has application potential in tumor-targeted gene therapy.     

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。     

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。