Mast cell tryptase promotes breast cancer migration and invasion.

It has been reported that the number of typtase-positive mast cells was significantly greater in breast peritumoral tissue. However, the significance of tryptase in tumor growth and metastasis is unknown. Tryptase in surgical breast cancer samples was stained by immunohistochemistry. The effects of tryptase on breast cancer proliferation, invasion and migration were observed in vitro. We found significantly more tryptase in peritumoral tissue than in normal breast tissue. The increased tryptase was associated with higher tumor grade and more lymph node metastasis. Tryptase promoted the invasion and migration of breast cancer cells along with activation of matrix metalloproteinase-2. Tryptase did not affect the proliferation of the cells. Our results indicate that tryptase promotes breast cancer migration and invasion.