Purpose: The aim of this study was to investigate effects of adipose-derived mesenchymal stem cells (AMSCs) on radioresistance of breast cancer cells.
Materials and methods: MTT assays were used to detect any influence of AMSC supernatants on proliferation of breast cancer cells; cell migration assays were used to determine the effect of breast cancer cells on the recruitment of AMSCs; the cell survival fraction post-irradiation was assessed by clonogenic survival assay; γ-H2AX foci number post-irradiation was determined via fluorescence microscopy; and expression of IGF-1R was detected by Western blotting.
Results: AMSC supernatants promoted proliferation and radioresistance of breast cancer cells. Breast cancer cells could recruit AMSCs, especially after irradiation. IGF-1 derived from AMSCs might be responsible for the radioresistance of breast cancer cells.
Conclusions: Our results suggest that AMSCs in the tumor microenvironment may affect the outcome of radiotherapy for breast cancer in vitro.