Li_2016_Mol.Med.Rep_13_2476

Cancerassociated fibroblasts (CAFs), key components of the tumor stroma, can regulate tumorigenesis by altering the tumor microenvironment in variety of ways to promote angiogenesis, recruit inflammatory immune cells and remodel the extracellular matrix. Using a murine xenograft model of colon carcinoma, the present study observed that oxaliplatin increased the accumulation of CAFs and stimulated the production of cytokines associated with CAFs. When oxaliplatin was combined with the smallmolecule dipeptidyl peptidase inhibitor PT100, which inhibits CAFs by targeting fibroblast activation protein (FAP), the accumulation of CAFs was markedly reduced, xenograft tumor growth was significantly suppressed and the survival of the mice increased, compared to those of mice treated with oxaliplatin or PT100 alone. Furthermore, the xenograft tumor tissues of mice treated with oxaliplatin and PT100 contained lower numbers of tumorassociated macrophages and dendritic cells, expressed lower levels of cytokines associated with CAFs and had a lower density of CD31+ endothelial cells. The present study demonstrated that pharmacological inhibition of CAFs improved the response to chemotherapy, reduced the recruitment of immune tumorpromoting cells and inhibited angiogenesis. Combining chemotherapy with agents which target CAFs may represent a novel strategy for improving the efficacy of chemotherapy and reducing chemoresistance.