The relationship of lncRNA NR2F1 and breast cancer angiogenesis via IL-8/lncRNA NR2F1/miR-200s/IL-8 loop.

Abstract

e12573 Background: Angiogenesis is key for metastasis and predicts a poor prognosis in breast cancer. Among the pro-angiogenic factors, interleukin-8 (IL-8) could be secreted by tumor cells mediated by microRNA-200 family (miR-200s). Long non-coding RNA (LncRNA), was reported to absorb microRNA to play multiple roles in various diseases including breast cancer. Our preliminary results recognized lncRNA NR2F1 through Agilent Human LncRNA array from breast cancer cells overexpressing IL-8. However, the relationship between LncRNA NR2F1 and breast cancer angiogenesis remains unknown. Methods: Breast cancer cell migration, invasion, proliferation and angiogenesis were assessed by Transwell, CCK8, tube formation, and wound healing assays. The expression of LncRNA NR2F1, miR-200s and IL-8 were detected by qPCR, Western blotting and ELISA. Breast cancer metastasis and angiogenesis in vivo were measured in a zebrafish model. Results: We found that the basal expression of lncRNA NR2F1 is higher in breast cancer cell lines than it in normal cells. In vitro, lncRNA NR2F1 induced breast cancer migration, invasion, and proliferation. Meanwhile, lncRNA NR2F1 promoted human umbilical vascular endothelial cell (HUVEC) proliferation, tube formation, and migration both via breast cancer conditioned medium and via direct HUVEC transfection. In the zebrafish model, lncRNA NR2F1 promoted breast cancer cell metastasis and neo-angiogenesis. Further study disclosed that lncRNA NR2F1 downregulated the expression of miR-200s, which in turn upregulated the expression of IL-8 in breast cancer cells. Conclusions: Our findings suggest that LncRNA NR2F1, as a potential promoter of breast cancer, may induce breast cancer angiogenesis through IL-8/lncRNA NR2F1/miR-200s/IL-8 loop.