Integrin α3β1 in Hair Bulge Stem Cells Modulates CCN2 Expression and Promotes Skin Tumorigenesis

The study found that the deletion of integrin α3β1 in hair bulge stem cells (HB SCs) significantly reduced the formation of papillomas in a mouse model of skin cancer induced by DMBA/TPA. Contrary to previous beliefs, HB SCs stayed within their niche and were largely absent from skin tumors, even when α3β1 was deleted. The reduction in tumor formation was linked to the α3β1-dependent expression of the protein CCN2, which was shown to promote colony formation and 3D growth of transformed keratinocytes in vitro. This suggests that HB SCs may facilitate skin tumorigenesis by creating a conducive environment for tumor growth through the regulation of CCN2 secretion.