The protective effect of endurance running against the pro-invasive effects of ageing in breast cancer cells and mesenchymal stem cells in vitro.

Purpose: Regular exercise is known to reduce cancer risk and may prevent metastases, however, modelling this in vitro is challenging due the heterogeneity of the tumour microenvironment. Exercised serum can be used to capture changes in cellular signalling components in response to different types and durations of exercise. In this study, exercised serum from long-term endurance runners and sprinters of different ages was used to evaluate the impact of exercise on the invasiveness of breast cancer cells and mesenchymal stem cells in vitro.

Methods: Exercised serum from long-term trained younger and older endurance runners and sprinters was used to supplement cell culture media in the 3D culture of spheroids containing breast cancer cells or mesenchymal stem cells. Spheroids were generated in a 3D semi-solid matrix and cell invasion was measured using ImageJ software. Statistical analyses of invasion were conducted using one-way ANOVAs.

Results: Invasion was significantly greater in cells cultured with serum from older, inactive participants compared to young, inactive participants (YC vs OC; F _(1,3) = 37.135, P = 0.009). No significant difference was found in the invasion of MDA-MB-231 breast cancer cells cultured in serum from older, long-term endurance runners and younger, long-term endurance runners (YE vs OE; F _(1,3) = 5.178, P = 0.107), suggesting a protective effect of endurance running against the pro-invasive effects of ageing.

Conclusion: This is the first study of its kind to demonstrate the protective effects of long-term exercise training type in two populations of different ages against the invasiveness of breast cancer cells in vitro.