MALIGNANT TRANSFORMATION OF HUMAN PROSTATE EPITHELIAL-CELLS BY N-NITROSO-N-METHYLUREA

We report the malignant transformation of adult human prostate epithel ial cells after multiple exposures to the chemical carcinogen N-nitros o-N-methylurea. Such transformants showed morphological alterations an d anchorage-independent growth in soft agar and induced carcinomas whe n transplanted into nude mice, No p53 or ms mutations were observed, S tepwise chromosomal changes in the progression to tumorigenicity were observed. Loss of the p arms of chromosome 8 (p10>pter) and chromosome 10 (p10>pter) and gain of the q arm of chromosome 8 (q10>qter) were o nly observed in the tumor outgrows, These findings provide the first e vidence of malignant transformation of human prostate epithelial cells exposed to a chemical carcinogen.