Incorporation of 32P into nucleic acids in mammary tissue of mice susceptible and resistant to breast cancer.

Incorporation of 32p into RNA and DNA fractions of mammary and tumor tissue was studied in virgin C3H mice, which are susceptible to the development of breast cancer. Virgin C57BL mice, which are resistant to the development of breast cancer, were the controls. Virgin C3H and C57BL mice, 4 and a months old, and tumor-bearing C3H mice were used as the experimental groups. The incorporation of 32p into RNA and DNA fractions did not dirfer signiAcantly among the 4and a-month-old, virgin C3H mice. The tumor tissue had the highest rate of uptake of 32p into both nucleic acids. In castrated C3H mice and CS7BL females, the incorporation of 32p into nucleic acids in the mammary tissue of the C57BL females was significantly lowered, whereas in the C3H mice it remained comparable with that observed in the corresponding control groups.-J Nat Cancer Inst 46: 731-734,1971.