Preclinical study for gene therapy against bladder cancer utilizing gelsolin gene and a dominant negative ras mutant

我们研究了用凝溶胶蛋白基因对人膀胱癌细胞系裸鼠进行基因治疗的体内疗效。这种形式的基因治疗，其中逆转录病毒生产细胞的引入，导致显着的和可重复的肿瘤生长抑制和延长的生存时间在大多数动物tested.We还研究了是否N116 Y，它来自于v-H-ras癌基因的天冬酰胺-116以酪氨酸取代，也可以抑制人膀胱癌细胞系的生长。最初，我们研究了N116 Y对转化表型和Ras信号通路的抑制作用。这些研究表明，N116 Y能够抑制人膀胱癌细胞系中的转化表型，即使其表达相对较低。为了分析N116 Y抑制作用的机制，我们检测了可能受N116 Y影响的人膀胱癌细胞系中Grb 2和Sos蛋白的表达。这些结果表明，与培养的正常尿路上皮细胞相比，Grb 2和Sos蛋白在人膀胱癌细胞系中的表达显著增加。最后，我们研究了AdCMV-N116 Y对裸鼠原位移植人膀胱癌细胞的抑制作用。经尿道接种AdCMV-N116 Y对膀胱癌的生长有明显的抑制作用，提示AdCMV-N116 Y膀胱内接种对膀胱癌的治疗有很好的疗效，有望成为膀胱癌的一种新的治疗方法。

We investigated the in vivo efficacy of gene therapy with the gelsolin gene in nude mice with human bladder cancer cell lines. This form of gene therapy, in which retrovirus producer cells were introduced, resulted in marked and reproducible tumor growth inbibition and prolonged survival time in the majority of animals tested.We also examined whether N116Y, which derived from the v-H-ras oncogene by substituting the asparagine-116 with tyrosine, can also inhibit the growth of human bladder cancer cell lines. Initially, we examined suppressive effects of the N116Y on transformed phenotypes and Ras signaling pathways. These studies demonstrated that the N116Y was capable of suppressing the transformed phenotype in human bladder cancer cell line, even when its expression is relative low. To analyze the mechanism of suppressive effects of N116Y, we examined the expression of Grb2 and Sos proteins, which are probably affected by N116Y, in human bladder cancer cell lines. These results showed that expression of Grb2 and Sos proteins were significantly increased in human bladder cancer cell lines in comparison with cultured normal urothelial cells. Lastly, we examined the inhibitory effects of AdCMV-N116Y on orthotopically-implanted human bladder cancer cells in nude mice. The in vivo growth of implanted bladder cancer was significantly inhibited by transurethral inoculation of AdCMV-N116Y.These results suggest that the inoculation of AdCMV-N116Y into the bladder is highly effective for remission of bladder cancer, and this therapy would be very useful as a novel treatment of human bladder cancer.