ABSTRACT
@#[Abstract] Objective: To explore the expression of long non-coding RNA (lncRNA) GTSE1-AS1 in prostate cancer tissues and the mechanism that affects the proliferation and invasion of LNCaP cells. Methods: From November 2017 to December 2018, 68 pairs of prostate cancer tissue and para-cancerous tissue specimens were resected from prostate cancer patients at the Department of Urology of Luoyang Central Hospital Affiliated to Zhengzhou University; in addition, prostate cancer cell lines LNCaP, PC-3, C4-2B, 22Rv1, DU-145 and normal prostate follicular epithelial RWPE-1 cells were also chosen for this study. qPCR was used to detect the expression level of GTSE1-AS1 in cancer tissues and cell lines. The GTSE1-AS1 over-expression plasmid (experimental group) and negative control plasmid (control group) were respectively transfected into LNCap cells. MTT assay and Transwell chamber method were used to detect the effect of GTSE1-AS1 over-expression on the proliferation and invasion ability of LNCaP cells, respectively. The targeting relationship among GTSE1-AS1 and miR-324-3P as well as FBXW7 (F-frame/WD repeat domain protein 7) was verified by bioinformatics tools and dual-luciferin reporter gene assay. The effect of GTSE1-AS1 over-expression on downstream gene and protein expression was detected by qPCR and WB assay. Results: The expression level of GTSE1-AS1 in prostate cancer tissues was significantly lower than that in para-cancerous tissues (P<0.01), and the expression of GTSE1-AS1 in prostate cancer cell lines was significantly lower than that in RWPE-1 cells (P<0.05 or P<0.01). Over-expression of GTSE1-AS1 significantly inhibited the proliferation and invasion (P<0.05 or P<0.01) of LNCaP cells. Dual-luciferin reporter gene assay confirmed the complementary binding between GTSE1-AS1 and miR-324-3p as well as between miR-324-3p and FBXW7. Over-expression of GTSE1-AS1 significantly reduced the expression of miR-324-3p in LNCaP cells (P<0.01), and promoted the mRNA and protein expressions of FBXW7 (all P<0.01). Conclusion: GTSE1-AS1 is under-expressed in prostate cancer tissues and cell lines. Over-expression of GTSE1-AS1 can inhibit the proliferation and invasion of LNCaP cells, the mechanism of which may be related with the inhibition of miR-324-3p to further promote FBXW7 expression.