Comparative chromosome study of normal mammary tissue, carcinogen-induced mammary tumors, and hyperplastic alveolar nodules in the rat: Brief communication.

The chromosome constituents of 101 normal mammary gland cells, 122 hyperplastic alveolar nodule (HAN) cells, and 360 cells from eleven 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumors in the WF rat were examined. Both mammary gland and HAN had normal diploid karyotype patterns, whereas mammary tumors showed frequent (approximately 30%) abnormalities, e.g., aneuploidy, pseudodiploidy, polyploidy, and structural aberrations such as breakage and translocation. These results suggested that chromosome constituents of HAN cells are essentially the same as those of the normal mammary epithelial cells.