Effects of FSTL1 on the proliferation and motility of breast cancer cells and vascular endothelial cells.

BACKGROUND: Treatments that prevent the motility of breast cancer cells and inhibit formation of new capillary vessels are urgently needed. FSTL1 is a secreted protein that has been implicated in maintaining the normal physiological function of the cardiovascular system, in addition to a variety of other biological functions. We investigated the role of FSTL1 in the proliferation and migration of breast cancer and vascular endothelial cells.

METHODS: Human umbilical vein endothelial cells and human breast cancer BT-549 cells were used to test the effects of FSTL1 and the N-terminal domain of FSTL1. Immunofluorescence microscopy and 3-(4, 5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide, transwell invasion, and wound healing assays were conducted.

RESULTS: Different doses of the N-terminal fragment of FSTL1 (FSTL-N) have variable effects on the migration of these cells. However, FSTL1 does not significantly affect tube formation in vitro from vascular endothelial cells. FSTL1-FL and FSTL1-N have modest effects on the invasion of breast cancer and vascular endothelial cells. Interestingly, FSTL1-FL, but not FSTL-N, modulates vascular endothelial cell polarization.

CONCLUSION: FSTL1 modestly affects the proliferation of breast cancer cells and vascular endothelial cells. Our findings improve our understanding of the functions of FSTL1 in breast cancer development and angiogenesis.