Introduction of wild-type p53 gene downregulates the expression of H-ras gene and suppresses the growth of bladder cancer cells.
Retroviral vectors were used to introduce the wild-type p53 gene into human bladder cancer cell lines BIU-87 and EJ, which express endogenous wt-p53 gene and have a mutation in H-ras gene. The expression of the exogenous wt-p53 gene in cells suppresses the growth of the bladder cancer cells in standard culture and in soft agar and blocks the cell cycle progression in G1. The BIU-87 and EJ cells developed tumors with average volumes of 6.53 cm3 and 6.61 cm3 in nude mice in 9 weeks after inoculation, while the cells transduced with wt-p53 gene failed to form tumors. The expression of H-ras gene in bladder cancer cells was reduced at mRNA level. These results suggest that the overexpression of the wt-p53 gene suppresses the expression of mutant H-ras gene and inhibits the tumor cell growth in vivo and in vitro.
Li
M
M
Institute of Urology, Beijing Medical University, China.
Gu
F L
FL
Li
W B
WB
Song
Y S
YS
Zhou
A R
AR
Guo
Y L
YL
D000818:Animals; D015197:Carcinogenicity Tests; D002453:Cell Cycle; D002455:Cell Division; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D016158:Genes, p53; D011905:Genes, ras; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000473:pathology*