Brief Communication: Chemical Carcinogen-Induced Alveolar Nodules in Organ Culture of Mouse Mammary Gland2

Abstract

The entire second thoracic mammary glands of immature C3Hf/HeCr (fostered on C57BL) female mice were treated with 7,12-dimethylbenz[a]anthracene or 3-methylcholanthrene in acetone or dimethyl sulfoxide supplemented with mammogenic protein and steroid hormones, during lobulo-alveolar growth in organ culture. Multiple hyperplastic alveolar nodules were found in the carcinogen-treated glands after regression of the normal alveoli in medium with insulin alone. Virtually no nodulelike structures were present in the control glands treated with the solvents. Morphology and histology of the carcinogen- induced nodules in organ culture were indistinguishable from the precancerous nodules of mouse mammary gland in vivo.