National Engineering Laboratory for AIDS Vaccine, the Ministry of Education, College of Life Science, Jilin University, Changchun 130012, PR China.
Oncol Rep. 2011 Jul;26(1):255-64. doi: 10.3892/or.2011.1285. Epub 2011 Apr 28.
Breast cancers especially in the late and metastatic stages remain refractory to treatment despite advances in surgical techniques and chemotherapy. Tumor-specific promoter-directed suicide gene therapy and adenoviral technology can be promising strategies for such advanced disease. Previous studies suggested that combining herpes simplex virus thymidine kinase (HSV-TK) and ganciclovir (GCV) with Escherichia coli nitroreductase (Coli.NTR) and 5-(azaridin-1-yl)-2, 4-dinitrobenzamide (CB1954) by a recombinant retrovirus delivery system resulted in a co-operative killing effect in vitro. We constructed a bicistronic adenovirus type 5 (Ad5)-based vector which co-expresses herpes HSV-TK and Coli.NTR under the control of the human telomerase reverse transcriptase (hTERT) promoter and SV40 enhancer. NTR gene expression mediated by an internal ribosome entry site (IRES) was inserted after the hTERT and HSV-TK sequences. Anti-tumor activities of the novel vector, Ad-hT-TK/NTR-enh, combined with prodrugs were evaluated in human breast cancer cells (ZR-75-30, MCF-7) in vitro and in vivo. We showed that expression of HSV-TK and NTR genes by Ad-hT-TK/NTR-enh in combination with GCV and CB1954 resulted in specific and significant cytotoxic effects in breast cancer cells in vitro. The anti-tumor activity of this system was more efficient than that from a single suicide gene, and only slightly lower than by HSV-TK and NTR driven from separate hTERT promoters in vitro and in vivo while the total amount of adenovirus of Ad-hT-TK/NTR-enh was half that of Ad-hT-TK-enh+Ad-hT-NTR-enh. These results suggest that suicide genes HSV-TK and NTR mediated by a single adenovirus vector under the control of an enhanced hTERT promoter results in additive anti-tumor effects and may provide a relatively safe strategy for the treatment of breast cancer by tumor-specific targeting.
尽管在外科技术和化疗方面取得了进步，但乳腺癌尤其是晚期和转移性乳腺癌仍然对治疗有抗性。肿瘤特异性启动子指导的自杀基因治疗和腺病毒技术可能是治疗此类晚期疾病的有前途的策略。以前的研究表明，通过重组逆转录病毒传递系统将单纯疱疹病毒胸苷激酶（HSV-TK）和更昔洛韦（GCV）与大肠杆菌硝基还原酶（Coli.NTR）和 5-（氮杂-1-基）-2,4-二硝基苯甲酰胺（CB1954）结合在一起，可在体外产生协同杀伤作用。我们构建了一种双顺反子腺病毒 5 型（Ad5）载体，该载体在人端粒酶逆转录酶（hTERT）启动子和 SV40 增强子的控制下共表达单纯疱疹 HSV-TK 和 Coli.NTR。NTR 基因表达由内部核糖体进入位点（IRES）介导，插入 hTERT 和 HSV-TK 序列之后。新型载体 Ad-hT-TK/NTR-enh 与前药联合的抗肿瘤活性在体外和体内的人乳腺癌细胞（ZR-75-30、MCF-7）中进行了评估。我们表明，Ad-hT-TK/NTR-enh 表达的 HSV-TK 和 NTR 基因与 GCV 和 CB1954 联合使用，可导致乳腺癌细胞的特异性和显著细胞毒性作用。该系统的抗肿瘤活性比单个自杀基因更为有效，仅略低于单独的 hTERT 启动子驱动的 HSV-TK 和 NTR ，而 Ad-hT-TK/NTR-enh 的腺病毒总量为 Ad-hT-TK-enh+Ad-hT-NTR-enh 的一半。这些结果表明，由增强的 hTERT 启动子控制的单个腺病毒载体介导的自杀基因 HSV-TK 和 NTR 可导致相加的抗肿瘤作用，并且可能为通过肿瘤特异性靶向治疗乳腺癌提供一种相对安全的策略。
