Refeeding differentially affects tumor and host cell proliferation.

Tumor and host tissue DNA synthesis in C3H female mice with MA16/C tumors were examined for the effects of starvation and refeeding. Animals with subcutaneously implanted tumors were randomized to either regular diet or starvation for 48 hr followed by refeeding for 6, 12, 24, 48, or 72 hr. With starvation, both tumor and host tissues demonstrated a decrease in DNA synthetic activity. After refeeding, resumption in DNA tumor synthesis preceded that of host tissues and was greatest within the first 6-12 hr. Host tissue DNA synthetic activity resumed at different times in the various tissues examined with bone marrow being earlier than spleen or liver. The differential time course between induction of tumor and host DNA synthesis could allow a more precise modeling in studies dealing with the interaction of nutritional repletion and antitumor therapy.