[p53 gene mutations in mouse skin tumors induced by DMBA-TPA-MNNG].
OBJECTIVE
To investigate the relationship between p53 gene mutations and mouse skin tumors induced by three-step carcinogenesis.


METHODS
The exons 5-8 of p53 gene were examined in 37 DMBA-TPA-MNNG induced mouse skin tumors [including 6 mice with papillomas, 15 mice having well differentiated squamous cell carcinomas (SCCI) and 16 mice with intermediately differentiated squamous cell carcinomas (SCC II)].


RESULTS
No p53 gene mutation was detected in the papilloma group, whereas 25.8% (8/31) of the SCC group had p53 gene mutations (4/15 of the SCC I mice and 4/16 of the SCC II mice). A total of 9 mutations were found in 8 mice with SCC, of which 7 were located in exon 8 and 7 were G-->A transitions.


CONCLUSIONS
The p53 gene mutations occurred during the process of malignant transformation from papilloma to SCC induced by three step carcinogenesis.
Department of Pathology, West China University of Medical Sciences, Chengdu 610041.
S
S
Zhang
Guo
A
A
Klein-Szanto
D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000235:genetics*; D002471:Cell Transformation, Neoplastic; D005091:Exons; D016158:Genes, p53; D008769:Methylnitronitrosoguanidine; D051379:Mice; D018632:Mice, Inbred SENCAR; D010212:Papilloma / Q000139:chemically induced / Q000235:genetics; D017354:Point Mutation; D012878:Skin Neoplasms / Q000139:chemically induced / Q000235:genetics*; D013755:Tetradecanoylphorbol Acetate
D008769:Methylnitronitrosoguanidine; D015127:9,10-Dimethyl-1,2-benzanthracene; D013755:Tetradecanoylphorbol Acetate