Pagliaro Lance C, Keyhani Afsaneh, Liu Baoshun, Perrotte Paul, Wilson Deborah, Dinney Colin P
Department of Genitourinary Medical Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA.
Urol Oncol. 2003 Nov-Dec;21(6):456-62. doi: 10.1016/s1078-1439(03)00032-2.
Mutations of the tumor suppressor gene p53 are common in bladder cancer. To determine whether p53 gene transfer would lead to decreased viability of bladder cancer cells, we studied the effect of p53 gene transfer in human bladder cancer cell lines with either mutant or wild-type p53. Bladder cancer cell lines 5637 and J82 (which express only mutant p53) and 253J-BV (which expresses wild-type p53) were transduced with vectors containing the beta-galactosidase gene (Ad5-lacZ), wild-type human p53 gene (Ad5CMV-p53), or no foreign gene (DL312 or Ad5-polyA). X-gal staining of cells exposed to Ad5-lacZ showed that the adenoviral vector was capable of transducing each of the cell lines. Increases in p53, p21(waf1/cip1) and bax protein were demonstrated following exposure to Ad5CMV-p53, and there was a dose-dependent increase in the number of apoptotic cells. Cell viability was decreased in all three cell lines, although J82 was less sensitive than either 5637 or 253J-BV. To determine whether cisplatin increases sensitivity of J82 cells to Ad5CMV-p53, we performed median effect analysis for cisplatin combined with Ad5CMV-p53 or DL312. The combination index for cisplatin plus Ad5CMV-p53 revealed synergy, whereas cisplatin and DL312 were only additive. These results suggest that forced p53 gene expression is cytotoxic to human bladder cancer cells with either p53 mutant or wild-type background, and that combination with cisplatin is a potential method for overcoming resistance.
肿瘤抑制基因p53的突变在膀胱癌中很常见。为了确定p53基因转移是否会导致膀胱癌细胞活力下降，我们研究了p53基因转移对具有突变型或野生型p53的人膀胱癌细胞系的影响。用含有β-半乳糖苷酶基因（Ad5-lacZ）、野生型人p53基因（Ad5CMV-p53）或无外源基因（DL312或Ad5-polyA）的载体转导膀胱癌细胞系5637和J82（仅表达突变型p53）以及253J-BV（表达野生型p53）。对暴露于Ad5-lacZ的细胞进行X-gal染色表明腺病毒载体能够转导每个细胞系。暴露于Ad5CMV-p53后，p53、p21（waf1/cip1）和bax蛋白增加，并且凋亡细胞数量呈剂量依赖性增加。所有三个细胞系的细胞活力均下降，尽管J82比5637或253J-BV敏感性低。为了确定顺铂是否会增加J82细胞对Ad5CMV-p53的敏感性，我们对顺铂与Ad5CMV-p53或DL312联合进行了中位效应分析。顺铂加Ad5CMV-p53的联合指数显示协同作用，而顺铂和DL312仅为相加作用。这些结果表明，强制p53基因表达对具有p53突变或野生型背景的人膀胱癌细胞具有细胞毒性，并且与顺铂联合是克服耐药性的一种潜在方法。
