The Inhibitory Effect of Exogenous Wild-Type p53 Gene on the Cell Growth and Tumorigenicity of Human Gallbladder Cancer Cell Lines / 中国肿瘤生物治疗杂志

Objective: To investigate effect of exogenous wild-type p53 gene on the cell growth and tumorigenicity of human gallbladder cancer cell lines. Methods: After identification of the genetic status of p53 gene of GBC-SD cell lines with the immunocytochemistry staining and the direct sequencing technique of PCR products, eukaryotic expressing plasmid pCMV-p53 was introduced by lipofectamine-mediated into GBC-SD cell lines. Growing transfected cells were selected by G418. The presence and expression of exogenous p53 gene was detected by PCR, RT-PCR and Western blot. The cellular proliferating ability was assessed using the cell growth curve and cloning assay. The xenograft in nude mice was performed to examine the effect of tumorigenicity. Results: P53 protein overexpression was showed in GBC-SD cell lines. A transversion of TAC→AAC at codon 126 of exon 5 was confirmed. PCR, RT-PCR and Western blot showed exogenous p53 gene had successfully transfected into GBC-SD cells and obtained high expression. The growth and proliferation of the cells were greatly decreased, and the tumorigenicity was significantly inhibited after transfection wtp53. Conclusion: The expression of exogenous wild-type p53 gene could effectively inhibit the growth of gallbladder cancer GBC-SD cells in vitro and in vivo.

Suppression of Growth and Tumorigcnicity in Human Gastric Cancer Cells by the Introduction of Exogenous p53 Gene / 中国肿瘤生物治疗杂志

The p53 gene is one of the most common targets for genetic abnormalities in human tumors. Restoring wild - type p53 gene (wt-p53) into cancer cells which have p53 deletion is a strategy in cancer gene therapy. In order to explore the feasibility of this hypothesis, we selected a gastric cancer cell line BGC823 which was confirmed having deletion of chromosome 17pl3 and decreased expression level of p53 mRNA . We transfected construct pC53SN3 containing wt - p53 into BGC823 cell line with lipofectin mediated gene transferration, and G418 resistant colonies were characterized by using analysis of PCR, Southern blot hybridization, Northern blot hybridization and Western blot hybridization. These data showed that exogenous wt-p53 had successfully transferred into BGC823 cells and obtained high expression. The cell growth rates in regular medium and soft agar were inhibited from 30 to 40 percent in the BGC823 cells transfected with wt - p53. The tumorigenicity in nude mice showed that one of four mice failed to form tumor and three of them delayed to form tumor from 7 to 14 days comparing with monk and parent BGC823 cells. These results suggested that exogenous wt -p53 could suppress the growth ability and tumorigenicity of human gastric cancer cells. The method of using lipofectin mediated wt-p53 gene transfection may have a potentially therapeutic effect on human gastric cancer.