反义端粒酶基因与顺铂诱导原代胃癌细胞凋亡作用的研究

目的 探讨端粒酶反义寡核苷酸 (PS- ASODN)与顺铂 (DDP)联合应用对原代胃癌细胞凋亡作用的影响。方法 常规组织块培养法进行胃癌细胞原代纯化培养 ,取第 3代对数生长期细胞分六组进行实验。其中四组在培养 2 4小时及 4 8小时分别加入相同剂量的培养液 ,终浓度为 PS- ASODN3μM,N- ASODN3μM,DDP2 .0μg/ ml。作用 2 4小时后分别在 PS- ASODN组及 N- ASODN组加入终浓度为 2 .0 μg/ ml的 DDP;分别于培养后 2 4、4 8、72及 96小时收集各组细胞。以台盼蓝拒染法计算各组细胞生长抑制率 ,观察 PS- ASODN联合 DDP对原代胃癌细胞生长的影响 ;流式细胞学观察细胞凋亡率及细胞周期变化。结果 终浓度为 3μM的 PS- ASODN作用于原代胃癌细胞 2 4小时后加入 DDP 2 .0μg/ m l,能明显抑制胃癌细胞增殖 ,流式细胞学可检测到凋亡峰 ,细胞受阻于G0 / G1 期 ,作用 4 8及 72小时的凋亡细胞百分率 (35 .1%、4 5 .7% )明显高于 N- ASODN组、PS- ASODN组、DDP组及 N- ASODN+DDP组 ,差异有显著性 (P<0 .0 5 )。其作用呈时间依赖性及序列特异性。结论 以端粒酶 RNA模板区为靶点的 PS- ASODN可促进 DDP诱导的胃癌细胞凋亡 。

端粒酶逆转录酶基因hTERT在肝细胞癌中的表达及端粒酶反义基因对人肝癌细胞HepG2细胞凋亡的影响

目的:研究肝细胞癌(HCC)中端粒酶逆转录酶基因hTERT表达,探讨其在HCC发生、发展及预后复发中的意义.探讨抗端粒酶在肝细胞癌治疗中的意义.方法:采用免疫组化法检测42例HCC组织中hTERT的表达,并对hTERT与临床病理特征的关系进行分析.将反义hTR真核表达载体经脂质体介导转染人肝癌细胞系HepG2,体外培养及接种裸鼠观察其基因转染细胞的细胞周期、超微结构变化及致瘤性.结果:HCC中hTERT基因阳性率分别为71.4%(30/42);hTERT与在正常肝脏组织中阳性表达率0%相比,有显著性差异(P<0.01).hTERT在Ⅰ,Ⅱ和Ⅲ级HCC中的表达率分别为40.0%(4/10),70.0%(14/20),100%(12/12).Ⅰ与Ⅲ级、Ⅱ与Ⅲ级比较差异显著(P<0.05).hTERT阳性表达率与患者复发有显著相关性(P<0.05).形态学观察,转染后HepG2细胞出现典型的凋亡现象.FCM检测发现G1期前出现凋亡峰.在裸鼠皮下的致瘤性明显降低.荷瘤鼠存活时间延长.结论:hTERT表达异常可能与肝脏肿瘤的发生、发展有关.检测hTERT表达可作为预测肝脏肿瘤预后复发的潜在指标.提示HCC是由多基因参与的疾病.转染端粒酶反义RNA能抑制肝癌HepG2细胞的恶性表型,促进其凋亡.

Inhibition of Telomerase with hTERT Antisense Increases Susceptibility of Leukemic Cells to CDDP-induced Apoptosis

Objective: To investigated the e?ect of inhibition of telomerase with hTERT antisense on leukemic cells (HL-60 and K562) to CDDP-induced apoptosis. Methods: Antisense phosphorothioate oligodeoxynucleotide (AS PS-ODN) was synthesized and puri?ed. Telomerase activity was detected by Telomerase PCR ELASA kit and cell apoptosis was observed by morphological method and determined by ?owcytometry. Results: AS PS-ODN could signi?cantly inhibit telomerase activity by down regulat- ing the hTERT expression, and increase the susceptibility of leukemic cells to CDDP-induced apoptosis. Conclusion: Inhibition of telomerase with hTERT antisense can increases the susceptibility of leukemic cells to CDDP-induced apoptosis.

Inhibition of Leukemic Cell Telomerase Activity by Antisense Phosphorothioate Oligodeoxynucleotides

Objective To evaluate the effect of human telomerase reverse transcriptase (hTERT) gene antisense oligodeoxynucleotide (ASODN) ontelomerase activity in K562 cells.Methods Telomerase activity was determined by polymerase chain reaction enzyme-linked immunoassay (PCR-ELISA) in K562 cellstreated with ASODN and hTERT mRNA expression was detected by reverse transcriptase polymerase chain reaction (RT-PCR).Results The hTERT mRNA level was decreased, and teloraerase activity was significantly inhibited when the K562 cells were treated withASODN for 48 h.Conclusion It is suggested that hTERT ASODN might specifically inhibit telomerase activity of K562 cells at translation level, and it isfurther proved that hTERT gene has significant correlation with telomerase activity.