[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.
Zhang
S
S
Department of Pathology, West China University of Medical Sciences, Chengdu 610041.
Guo
Klein-Szanto
A
A
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