Biological effects of cancer-secreted factors on human mesenchymal stem cells

Mesenchymal stem cells or mesenchymal stromal cells (MSCs) have been considered as a carrier of therapeutic gene because of their inherent ability to migrate to the tumors, and yet there are controversial reports suggesting the tumor-promoting and tumor-inhibiting effects of MSCs. Al-Toub and colleagues provide further insights into the cellular interactions between MSCs and tumors and demonstrate that conditioned media derived from different cancer cells could influence MSC phenotype and gene expression. These changes in MSCs may be modulated by the tumor-derived interleukin-1 beta (IL-1β) and transforming growth factor-beta (TGF-β) signaling.