A Comparative Study of the Biologic and Molecular Basis of Murine Mammary Carcinoma: A Model for Human Breast Cancer

Summary

Tritiated-DNA complementary to mouse mammary tumor virus (MMTV) RNA was synthesized in an endogenous reaction with MMTV particles. This DNA was used as a probe via molecular hybridization to detect MMTV-specific RNA in “spontaneous” mammary tumors of several strains of mice, including the “nonproducer” BALB/c mammary tumors. MMTV-specific RNA was also found in certain normal tissues (spleen, kidney, and epididymis) of a high-mammary-cancer strain (GR). Aging or treatment with nonviral carcinogens also induced the appearance of MMTV-specific RNA in certain normal tissues of the low-mammary-cancer strains, C57BL and BALB/c. The relationship of the presence of MMTV-specific RNA to the etiology and pathogenesis of murine mammary neoplasia and its potential application to human breast cancer are discussed.