Tissue-resident stem cells promote breast cancer growth and metastasis.

Mesenchymal stem cells derived from bone marrow have recently been described to localize to breast carcinomas and to integrate into the tumor-associated stroma. In the present study, we investigated whether adipose tissue-derived stem cells (ASCs) could play a role in tumor growth and invasion. Compared with bone marrow-derived cells, ASCs as tissue-resident stem cells are locally adjacent to breast cancer cells and may interact with tumor cells directly.