Long Non-Coding RNA SNHG19 Promotes Breast Cancer Progression by Regulating miR-299-5p

Abstract

Background: Accumulating evidence has suggested that long noncoding RNA (lncRNA) played crucial roles in the development of human malignances including breast cancer. SNHG19 is a newly identified lncRNA which exerted oncogenic function in non-small cell lung cancer, but whether SNHG19 was involved the development of other cancer, such as breast cancer still unclear. Methods: qRT-PCR was performed to examine the expression of SNHG19 and miR-299-5p in breast cancer tissues and cell lines. Cell proliferation was measure using CCK-8 and colony formation assay. Cell migration and invasion ability was detected by wound healing assay and transwell invasion assay. Bioinformatics analysis, dual luciferase reporter assay, RIP assay and Pull down assay were used to verify the direct binding between SNHG19 and miR-299-5p. The xenotransplantation mouse model was established to explore the effect of SNHG19 on breast cancer tumor growth in vivo.Results: We found that SNHG19 expression level was up-regulated in breast cancer tissues and cell lines, while miR-299-5p expression was down-regulated in breast cancer tissues and it was negatively correlated with SNHG19 expression. Silence of SNHG19 inhibited breast cancer cells proliferation, migration and invasion in vitro. Moreover, SNHG19 knockdown suppressed tumor growth of breast cancer cells in vivo. Mechanistically, SNHG19 acted as a ceRNA (competitive endogenous RNA) to sponge miR-299-5p. Finally, the rescue assays further confirmed that miR-299-5p inhibitor reversed the inhibitory effects of SNHG19 knockdown on breast cancer cell proliferation, migration and invasion.Conclusions: In conclusion, our findings proved that SNHG19 promoted breast cancer progression via sponging miR-299-5p and might function as promising prognostic indicator and therapeutic target for breast cancer.