Abstract
Breast cancer is a serious threat to women's physical and psychological health. Long noncoding RNA CAMTA1 (lncCAMTA1) was believed to be related with tumor progression, but its role in breast cancer is not clear. The human breast cancer cell line MDA-MB-231 was used to investigate the effect of lncCAMTA1 on cell viability, migration/invasion, and apoptosis. The expression of lncCAMTA1, miR-20b, and VEGF in MDA-MB-231 were measured after corresponding transfections. Binding effects between lncCAMTA1 and miR-20b, miR-20b, and VEGF 3'-UTR were measured. The effects of miR-20b and VEGF on breast cancer cells were also assessed after transfections. The phosphorylation levels of the MAPK/ERK and JAK/STAT3 pathways were determined to assess the effect of VEGF. The results showed that lncCAMTA1 expression promoted cell viability and migration/invasion, while knockdown of lncCAMTA1 promoted cell apoptosis via binding with miR-20b. lncCAMTA1 negatively regulated miR-20b expression. VEGF was a target of miR-20b, leading to the modification of the phosphorylation levels of MAPK, ERK, JAK, STAT1, and STAT3. Our findings suggested that lncCAMTA1 might promote proliferation and mobility of human breast cancer cells via binding with miR-20b. VEGF was a direct target of miR-20b and regulated activation of the MAPK/ERK and JAK/STAT3 signaling pathways. Therefore lncCAMTA1 has potential as a novel cancer diagnostic marker and as a putative novel therapeutic target for breast cancer treatment.