Cancer associated fibroblasts: phenotypic and functional heterogeneity.

Cancer associated fibroblasts (CAFs) are the most abundant stromal cell-type in solid tumor-microenvironment (TME) and have emerged as key player in tumor progression. CAFs establish communication with cancer cells through paracrine mechanisms or via direct cell adhesion as well as influence the cancer cell behaviour indirectly by remodelling the extracellular matrix. Although numerous studies have strongly suggested the tumor promoting role of CAFs, few recent reports have revealed the heterogeneity in CAFs. Here, we have summarized the recent findings on the mechanisms related to the heterogeneous behaviour of CAFs serving as positive or negative regulator of tumor progression. Further, reports related to the targeted therapy against CAF-mediated mechanisms are also summarized briefly.