Long non-coding RNA NKILA inhibited angiogenesis of breast cancer through NF-κB/IL-6 signaling pathway

Objective: The relationship between NF-kappa B Interacting lncRNA (NKILA) and angiogenesis in breast cancer has never been studied. Our study aimed to investigate effect of NKILA on proliferation, migration, apoptosis, as well as angiogenesis in breast cancer. Methods: NKILA was over-expressed in MDA-MB-231 cells by transfection of pcDNA3.1-NKILA vector. Cell viability, apoptosis and migration were measured by MTT, flow cytometry and wound healing assays, respectively. Angiogenesis of human umbilical vein endothelial cells (HUVEC) was measured using tube formation assay. The expression levels of NKILA, IL-6, VEGFA, VEGFR, apoptosis and epithelial-mesenchymal transition (EMT) and NF-kappa B/IL-6 signaling-related markers were determined using qRT-PCR or Western blotting. Results: Cell viability and migration of MDA-MB-231 cells were significantly inhibited, while cell apoptosis was obviously promoted by overexpression of NKILA. Overexpression of NKILA could also inhibit the phosphorylation of I kappa B alpha and the nuclear transposition of p65, as well as induce cell apoptosis-related proteins and inhibit epithelial-mesenchymal transition-related proteins. Cell viability and migration of HUVEC were also significantly inhibited when treated with supernatant of cells overexpressed NKILA or treated with BAY11-7028. Exogenous IL-6 significantly increased the cell viability and migration of HUVEC, and overexpression of NKILA could reverse these effects induced by IL-6. Overexpression of NKILA significantly inhibited the protein levels of IL-6 and VEGFA in supernatant, as well as VEGFR in HUVEC, thus inhibited the angiogenesis of HUVEC. NKILA also reversed the above effects on protein levels of IL-6 and VEGFA in supernatant and angiogenesis induced by exogenous IL-6. Conclusion: Overexpression of NKILA could inhibit cell proliferation, migration and promote apoptosis of breast cancer cells. It could also inhibit cell proliferation, migration and angiogenesis of HUVEC through inhibiting IL-6 secretion via NF-kappa B signaling pathway.