Long noncoding RNA KCNQ1OT1 is correlated with human breast cancer cell development through inverse regulation of hsa-miR-107.

In this work, we investigated the expression pattern and regulatory function of long noncoding RNA (lncRNA) KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) in breast cancer. We found that KCNQ1OT1 was significantly upregulated in breast cancer cell lines. In lentiviral-transduced BT-549 and HCC1599 cells, KCNQ1OT1 knockdown impaired cancer cell functions, including in vitro proliferation and migration, and in vivo transplant growth. The possible sponging target of KCNQ1OT1, human microRNA-107 (hsa-miR-107), was confirmed to be bound by KCNQ1OT1, and was upregulated in breast cancer cells with KCNQ1OT1 downregulation. Further, hsa-miR-107 knockdown in KCNQ1OT1-downregulated cancer cells reversed its impairing effects on cancer cell proliferation and migration in vitro. Thus, loss of KCNQ1OT1 is associated with functional impairment in breast cancer cells, likely through inverse regulation of its sponging target, hsa-miR-107.