Inhibitory effect of voluntary running wheel exercise on the growth of human pancreas Panc-1 and prostate PC-3 xenograft tumors in immunodeficient mice

摘要

In the present study, we investigated the effect of voluntary exercise on the formation and growth of human pancreas Panc-1 and prostate PC-3 tumors in immunodeficient mice. Female severe combined immunodeficient (SCID) mice were injected subcutaneously with human pancreas cancer Panc-1 cells, and male SCID mice were injected subcutaneously with human prostate cancer PC-3 cells. Voluntary running wheel exercise for 63 days starting one week before the subcutaneous injection of Panc-1 or PC-3 tumor cells into SCID mice suppressed the growth of both Panc-1 and PC-3 tumors. The exercise regimen increased food and fluid consumption in both female and male mice. Exercise also decreased the size of the parametrial fat pads in female mice and the paradidymis fat pads in male mice, but there was no effect on body weight. Mechanistic studies showed that voluntary running wheel exercise inhibited proliferation as reflected by decreased mitosis, and the exercise regimen also stimulated apoptosis as reflected by increased caspase-3 (active form) expression in both Panc-1 and PC-3 tumors. Voluntary running wheel exercise decreased the ratio of the percent mitotic cells/apoptotic cells in Panc-1 and PC-3 tumors by 38% and 32%, respectively. The present study demonstrates an inhibitory effect of voluntary exercise on the growth of pancreas and prostate tumors in a SCID mouse xenograft model.