[Long noncoding RNA Linc00662 promotes the tumorigenesis of prostate cancer cells]

To investigate the expression of Linc00662 in PCa and its influence on the biological function of PCa cells.

Using qRT-PCR, we detected the expression of Linc00662 in the PCa tissue and cell lines and that in the adjacent normal prostatic tissue and epithelial WPMY-1 cells and analyzed the correlation between the expression of Linc00662 and the clinicopathological features of the PCa tissue. We transfected PC-3 and DU145 cells with siRNA, and verified the interference efficiency by qRT-PCR. We examined the effects of interfering with the Linc00662 expression on the proliferation, apoptosis, migration and invasiveness of PC-3 and DU145 cells by CCK-8 assay, Caspase 3/9 activity assay, wound-healing assay and Transwell invasion assay.

The expression of Linc00662 in the PCa tissue and cell lines was significantly up-regulated compared with that in the adjacent normal prostatic tissue and epithelial cells (P < 0.01), and the high expression of Linc00662 was positively correlated with the tumor stage (P = 0.002), primary tumor size (P = 0.006), lymph node metastasis (P = 0.001) and distant metastasis (P = 0.001). Transfection of si-Linc00662 into the PC-3 and DU145 cells significantly reduced the expression of Linc00662 (P < 0.01). Compared with the normal control, the PC-3 and DU145 cells in the Linc00662 interference group showed remarkably decreased proliferation, invasion and migration abilities (P < 0.01), but an increased rate of apoptosis (P < 0.01).

Linc00662 is highly expressed in PCa tissues and cells relatively. Knockdown of the Linc00662 expression may inhibit the proliferation, migration and invasiveness and promote the apoptosis of PCa cells. Therefore, Linc00662 could be considered as a new marker of PCa.