角蛋白19启动子介导自杀基因的肿瘤细胞凋亡研究

目的探讨角蛋白19（keratin19，K19）启动子驱动单纯疱疹病毒胸苷激酶（HSV．-TK）基因这一载体系统对肿瘤细胞凋亡的影响。方法构建K19启动子驱动的HSV-TK载体pK19-TK，分别转染鼠转化角质细胞系、人肺癌细胞系和两种宫颈癌细胞系，MYr和流式细胞法检测前体药物丙氧鸟苷（GCV）对肿瘤细胞的杀伤作用。结果成功构建出pK19-TK质粒；两种细胞系在转染后产生了对GCV的敏感性，以鼠转化角质细胞系（PAM212细胞系）为例，加入2ixmol／LGCV后有19．4％的细胞死亡，加入10ixmol／LGCV和100txmol／LGCV分别有44．4％、58．7％的细胞被杀死。结论利用肿瘤细胞的角蛋白19表达特性来诱导细胞死亡在上皮细胞来源肿瘤的基因治疗中有潜在的应用价值。

Anti-tumor activity by targeting the keratin-19 positive cells in carcinoma cell lines

To study the cytotoxicity of keratin 19 promoter-driven HSV-TK in cancer cell lines. Methods The promoter region of mice keratin 19 was amplified using PCR from genomic DNA and cloned into a vector containing the encoding region of HSV-TK to construct a new plasmid pK19-TK. After transfection of the plasmid into several cancer cells lines, including transformed mouse keratinocytes cell line, human lung carcinoma cell line and two cervical cancer cell lines, cytotoxicity of ganciclovir to tumor cells was assayed by both MIT assay and flow cytometry. Results In carcinoma cell lines which had higher keratin 19 expression than respective normal cells, significant apoptosis occurred in two cell lines in the presence of ganciclovir. In Pam212 cell line, 19.4%, 44.4% and 58.7% of the cells were killed after exposed to GCV at concentrations of 2, 10 and 100 ixmol/L respectively. Conclusion Cancer cells death induction utilizing the keratin expression pattern is of potential value to the treatment of epithelial-derived tumors.