Objective: Chemotherapy is an effective means of treating breast cancer, and cancer-specific replicative adenovirus is also a promising antitumor agent in recent years. Our investigation aims to demonstrate that CNHK300 can mediate selective antitumor efficacy and produce synergistic cytotoxicity with chemotherapy on HER-2 over-expressing breast cancer. Methods: We engineered the telomerase-dependent replicative adenovirus CNHK300 by placing the E1A gene under the control of the human hTERT promoter. By analysis of E1A expression, we proved the fidelity of hTERT promoter in adenovirus genome and the selective expression of E1A in telomerase-positive breast cancer cells but not in normal fibroblast cells. By proliferation test, we further showed efficient replication of CNHK300 in breast cancer cells with apparently attenuated proliferation in normal fibroblast cells. Finally, we demonstrated by MTT methods that CNHK300 virus caused potent cytolysis and produced synergistic cytotoxicity with chemotherapy in breast cancer cells with attenuated cytotoxicity on normal cells. Results: In this virus, the E1A gene is successfully placed under the control of the human hTERT promoter. CNHK300 virus replicated as efficiently as the wild-type adenovirus and caused intensive cell killing in HER-2 over-expressing breast cancer cells in vitro. In contrast, telomerase-negative normal fibroblast cells, which expressed no hTERT activity, were not able to support CNHK300 replication. Combined treatment of CNHK300 with paclitaxel improved cytotoxicity on cancer cells. Conclusion: We conclude that CNHK300 can produce selective antitumor efficacy and enhance the in vitro response of chemotherapy on HER-2 overexpressing breast cancer.
目的 :观察增殖型腺病毒载体介导的 m IL - 1 2基因对胃癌细胞的杀伤作用。 方法 :利用携带 m IL - 1 2基因的增殖型腺病毒转染胃癌细胞株 SGC- 790 1 ,通过病毒增殖实验、细胞病理效应、酶链免疫反应等分别观察病毒复制能力、病毒对胃癌细胞的杀伤作用及 m IL - 1 2表达水平。结果 :携带 m IL - 1 2基因的增殖型腺病毒转染胃癌细胞株 SGC- 790 1具有肿瘤增殖型腺病毒 ONYX- 0 1 5的相似作用 ,可在肿瘤细胞内复制、增殖并杀死肿瘤细胞 ,而并不能在正常细胞内复制及增殖。该病毒在肿瘤细胞内的增殖能力是传统载体的近千倍。该载体携带的 m IL - 1 2基因的表达量明显高于传统基因治疗的腺病毒载体体系 ,是传统基因治疗表达量的百倍。 结论 :CNHK2 0 0 - m IL - 1 2能在胃癌细胞中增殖并杀死胃癌细胞 ,并提高目的基因的表达水平 。
