DYSREGULATION OF THE RAS-ONCOGENE AND P53 TUMOUR SUPPESSOR GENE EXPRESSION IN THE POLYURETHANE INDUCED TUMOUR CELL LINES IN VITRO

摘要

The polyurethanes (PUs) in vitro induced tumor cell clones, namely, clone-2, 5 and 6, isolated from mouse Balb/c3T3 (A311) were further analysized the p21-ras-protein and p53 protein expression and the N, K, H-ras proto-oncogene and p53 tumor suppressor gene exon 5,6,7,8 sequence. Our experimental results shown that the tumor clones increase the ras-protein expression comparing with the untransformed control cell A3111. The tumor clones also slightly increase (p 0.05, only clone 2 p 0.05) the accumulation of p53 inside the cells comparing with A3111. No mutation were detected in the codon 12, 13 and 61 of N, K, H-ras proto-oncogene and p53 tumor suppressor gene exon 5, 6, 7 and 8. The results indicated that PUs induced tumors do not cause the ras-proto-oncogene and the p53 tumor suppressor gene mutation, therefore, the leachable substances of PUs come into the cells or through the signal pathway by the interaction between PUs surfaces and the cells cause the overexpression of the ras-protein and the p53. The ras-protein as a signal protein bound to GTP forming a P21-ras-GTP complex and transfer the signal to the nucleus, cause the cells to be tumorigenic and overproliferation.