인체 위암 세포주에 retroviral vector를 이용한 p53 종양 억제 유전자의 형질도입에 관한 연구

Abstract

PURPOSE: The development of new therapeutic modalities such as gene therapy, which still requires further investigation, is clearly important to improve the prognosis of gastric cancer. This study was conducted to evaluate the effect on the growth and the tumorigenicity of retrovirus-mediated p53 gene transduction into gastric cancer cells. MATERIALS AND METHODS: Human gastric cancer cell lines were cultured and their DNAs were analyzed to evaluate the p53 status with PCR-SSCP (polymerase chain reaction-single strand conformation polymorphism) and DNA sequencing. Retroviral supernatants were obtained from each producer cell line, PA317/LNCX and PA317/LNC/p53, after construction of retroviral vector LNC/p53 containing human p53 cDNA and producer cell line PA 317/ LNC/p53. To investigate the effect of retrovirus-mediated p53 gene transduction in human gastric cancer cell lines, the in vitro growth rates and in vivo tumorigenicities of the N-87 cell line having mutant p53 and the YCC-S-2 cell line having wild-type p53 were compared before and after infection with LNC/p53 retrovirus. RESULTS: The following results were obtained: 1) The growth inhibition of N-87 cells after p53 transduction was signficant when compared to that of the parent N-87 cells. The growth of the p53 transduced YCC-S-2 cells and the parent YCC-S-2 cells was not different. 2) In nude mice, the growth of tumors formed by N-87 cells was modestly inhibited after retrovirus-mediated wild-type p53 gene transduction. However, the growth of tumors formed by YCC-S-2 cells was not inhibited by retrovirus-mediated p53 gene transduction. 3) The expression rate of p53 protein after p53-containing retroviral infection in the KATO-III cell lines, which have no p53 gene, was dose-dependent on the m.o.i. of retrovirus, although it was not more than 15% with the m.o.i. of 100 upon immunohistochemical analysis. CONCLUSION: The growth inhibition by retrovirus-mediated p53 transduction in human gastric cancer cells was significant in a gastric cancer cell line having mutant p53 in vitro, and the growth of tumor masses formed by a gastric cancer cell line having mutant p53 was modestly inhibited after p53 transduction using retroviral vector in nude mice, although it was not statistically significant. Only modest inhibition of tumor growth using retrovirus-mediated p53 gene transduction in vivo is most likely to be due to low transduction efficiency.