IGF-1 from Adipose-Derived Mesenchymal Stem Cells Promotes Radioresistance of Breast Cancer Cells

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 influenceof AMSC supernatants on proliferation of breast cancer cells; cell migration assays were used to determine theeffect of breast cancer cells on the recruitment of AMSCs; the cell survival fraction post-irradiation was assessedby 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 proliferationand 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 forbreast cancer in vitro.