Treatment-induced secretion of WNT16B promotes tumor growth and acquired resistance to chemotherapy: implications for potential use of inhibitors in cancer treatment.

Innate or acquired resistance to chemotherapy presents an important and predictable challenge in cancer therapy. Malignant tumors consist of both neoplastic and benign cells such as stromal fibroblasts, which can influence the tumor's response to cytotoxic therapy. In a recent article in Nature Medicine, Sun et al. show that increased expression of Wnt family member wingless-type MMTV integration site family member 16B (WNT16B) by the tumor microenvironment in response to cytotoxic damage and signals through the canonical Wnt pathway to promote tumor growth and chemotherapy resistance. Such findings outline a mechanism by which cytotoxic therapies given in cyclical doses can actually augment later treatment resistance and may open the door to new areas of research and to the development of new therapeutic targets that block the DNA damage response program.