Long non-coding RNA LINP1 promotes the malignant progression of prostate cancer by regulating p53

We aim to investigate the expression of long non-coding RNA-LINP1 (lncRNA LINP1) in prostate cancer (PCa) and its potential mechanism.

The expression of lncRNA LINP1 in 74 pairs of PCa and normal tissues were detected by quantitative Real-time polymerase chain reaction (qRT-PCR); the relationship between its expression and the pathological features and prognosis of PCa was also analyzed. The expression of lncRNA LINP1 in the PCa cell line was verified by qRT-PCR. Knockdown of LINP1 was constructed by transfection of small interfering RNA (siRNA) in two PCa cell lines (Lncap and PC-3). The biological function of LINP1 was evaluated by cell counting kit-8 (CCK-8) assay, colony formation assay, migration and invasion assay, respectively. Finally, the potential mechanism of LINP1 was explored by Western blot and qRT-PCR.

qRT-PCR results showed a higher expression of LINP1 in PCa than that of normal tissues. Compared with PCa patients with a lower expression of LINP1, those with higher expression had a higher tumor stage, lymphatic metastasis and distant metastasis rate, and lower overall survival rate. Proliferation, invasion and metastasis in cells transfected with si-LINP1 were remarkably decreased than those transfected with negative control (si-NC). Moreover, the expressions of the key proteins in the p53 signaling pathway, including p53, PTEN, Akt and CDK2 were remarkably decreased in cells after knockdown of LINP1. In addition, a negative correlation between LINP1 and p53 was confirmed by rescue experiments.

Up-regulated LINP1 in PCa was correlated with a higher PCa stage, lymphatic metastasis, distant metastasis, and worse prognosis. Furthermore, LINP1 could promote the proliferative, migratory and invasive abilities of PCa by regulating the p53-signaling pathway.