hTR反义寡核苷酸联合全反式维甲酸的体内抗口腔鳞癌作用研究

The antitumor effect and mechanism of antisense oligonucleotide against hTR with all-trans retinoic acid on oral squamous cell carcinoma

目的:评价人端粒酶RNA模板(hRT)反义寡核苷酸联合全反式维甲酸的体内抑瘤效果,并对其作用机制进行初步探讨。方法:裸鼠皮下注射Tca8113细胞,建立荷瘤动物模型。分别给予端粒酶反义寡核苷酸、端粒酶正义寡核苷酸、全反式维甲酸、端粒酶反义寡核苷酸联合全反式维甲酸、端粒酶正义寡核苷酸联合全反式维甲酸治疗。治疗结束时,计算各处理组抑瘤效果。端粒酶重复序列扩增法(TRAP法)检测各实验组肿瘤端粒酶活性;Tunel法检测细胞凋亡水平;免疫组织化学法观察bcl-2和bax蛋白表达情况;透射电镜检测各实验组细胞超微结构。实验结果以SPSS10.0软件包进行单因素、双因素方差分析。结果:端粒酶反义寡核苷酸和全反式维甲酸治疗均可抑制肿瘤的生长,两者联合应用具有协同作用。治疗后组织标本与对照组比较,端粒酶活性明显下降、细胞凋亡数目增高,bcl-2蛋白表达下调(P<0.05)。结论:针对端粒酶hTR靶点的端粒酶反义寡核苷酸联合全反式维甲酸治疗,对荷瘤鼠具有协同抑制肿瘤生长的作用。其抑瘤作用机制可能是通过降低端粒酶活性而引起肿瘤细胞凋亡,bcl-2在此过程中起着重要作用。

PURPOSE： To evaluate the in vivo antitumor effect and mechanism of antisense oligonucleotides against hTR （As-ODN-hTR） combining with all-trans-retinoic acid （ATRA）. METHODS： In situ human oral squamous cell carcinoma models were established by subcutaneous injection of Tca8113 cells. The mice were treated with As-ODN-hTR alone, sense oligonucleotides against hTR（S-ODN-hTR） alone, ATRA alone, As-ODN-hTR plus ATRA, S-ODN-hTR plus ATRA. Tumors size and weight were assessed. Telomerase activity, apoptotic cells number, expression of apoptosis-related proteins （bcl-2/bax） and ultrastructural morphological changes of each tumor specimen were examined. All data were analyzed by one-way analysis of variance （ANOVA） and two-way ANOVA with SPSS 10.0 software package. RESULTS： A combination of As-ODN-hTR and ATRA had a synergistic antitumor effect. Meanwhile, significantly decreased telomerase activity, increased number of apoptotic cells, morphology of typical apoptosis and down-regulated bcl-2 were observed in the treated tissues （P〈0.05）. CONCLUSION： The combination of the two agents have a synergistic antitumor effect. Combination of As-ODN-hTR and ATRA may be a potential approach for the treatment of human OSSC cancer.