LncRNA MEG3 inhibits the progression of prostate cancer by facilitating H3K27 trimethylation of EN2 through binding to EZH2.

This study aims to study the effects of intra-nuclear lncRNA MEG3 on the progression of prostate cancer and the underlying mechanisms. Expressions of relative molecules were detected by Quantitative real time PCR (qRT-PCR) and western blot. Chromatin immunoprecipitation and RNA immunoprecipitation (RIP) assays were used to evaluate the interaction between intra-nuclear MEG3, histone methyltransferase EZH2 and Engrailed-2 (EN2). The impacts of MEG3 on the viability, proliferation and invasion of prostate cancer cells (PC3) were evaluated by methyl thiazolyl tetrazolium, colony formation and transwell assays, respectively. PC3 cells were transfected with MEG3 and transplanted into nude mice to analyse the effect of MEG3 on tumourigenesis of PC3 cells in vivo. EN2 expression was inversely proportional to MEG3 in the prostate cancer tissues and PC3 cells. RIP results showed that intra-nuclear MEG3 could bind to EZH2. Knockdown of MEG3 and/or EZH2 up-regulated EN2 expression and reduced the recruitment of EZH2 and H3K27me3 to EN2, while over-expressed MEG3 caused opposite effects. MEG3 over-expression suppressed cell viability, colony formation, cell invasion and migration of PC3 cells in vitro and inhibited tumourigenesis of PC3 cells in vivo, while EN2 over-expression diminished the effects. These findings indicated that MEG3 facilitated H3K27 trimethylation of EN2 via binding to EZH2, thus suppressed the development of prostate cancer.

Transperitoneal versus extraperitoneal approach in laparoscopic radical prostatectomy: A meta-analysis.

BACKGROUND: To compare the transperitoneal approach with extraperitoneal approach in laparoscopic radical prostatectomy (LRP) (including pure and robotic-assisted LRP) using meta-analytic techniques. METHODS: Medline (PubMed), Embase, Ovid, CMB, and Cochrane databases were searched for studies that compared the transperitoneal and extraperitoneal approaches in LRP from January 2000 to January 2017. Outcomes included were operative time, operative bloods joss (milliliters), rate of transfusion, rate of open conversion, rate of intraoperative complications, rate of postoperative complications, and time of postoperative catheterization. RESULTS: Thirteen studies including 1674 patients were selected for the meta-analysis. 850 (50.8%) cases had undergone transperitoneal LRP (TLRP) and 824 (49.2%) cases had undergone the extraperitoneal LRP (ELRP). Comparison of operative time between the TLRP group and the ELRP group showed no significant differences (weighted mean difference [WMD] = 21.21,95%CI = -1.16-43.57, P = .06). No significant differences were observed in blood loss (WMD = -6.04, 95%CI = -43.38-31.29, P = .75) and the rate of transfusion (odds ratio [OR] = 1.03, 95%CI = 0.55-1.96, P = .92) between the 2 groups. No significant differences were observed for the rate of intraoperative complications (OR = 1.25, 95%CI = 0.57-2.21, P = .75) and the rate of open conversion (OR = 1.12, 95%CI = 0.32-4.97, P = .75). Significant differences were observed in the TLRP group compared with the ELRP group (OR = 1.69, 95%CI: 1.23-2.32, P = .001) regarding the rate of postoperative complications. CONCLUSIONS: Our meta-analysis findings revealed that the TLRP group showed no significant differences in most important indicators compared with ELRP. Moreover, TLRP showed higher rate of postoperative complications compared with ELRP.

Down-regulation of miR-605 promotes the proliferation and invasion of prostate cancer cells by up-regulating EN2.

AIMS: MicroRNA served as inhibitor for gene expression in various cancers. This study aimed to investigate the role of miR-605 and EN2 in prostate cancer (PCa). MATERIALS AND METHODS: In this research, the expression of miR-605 and EN2 protein in PCa tissues and cells were determined by qRT-PCR and western blot, respectively. The cell proliferation was measured by Cell Counting Kit-8 (CCK-8) and the tumor cell invasion assay was accomplished with transwell system. Flow cytometry was used to analyze the cell cycle. The endogenous expression of miR-605 and EN2 was modulated by recombinant plasmids and cell transfection. Dual luciferase reporter assay was performed to determine the interaction between miR-605 and EN2 in PCa cells. KEY FINDINGS: The expression of miR-605 was lower in PCa tissue and cells than that in normal tissues and cells, while the expression of EN2 was just the opposite. Down-regulation of the EN2 by siRNA inhibited the proliferation and invasion of PC3 cells, and the cell cycle was arrested in G0/G1 phase. EN2 regulated the expression of E-cadherin and Vimentin through Snail and EN2 regulated the cell cycle and cell proliferation via PI3K/AKT pathway. MiR-605 inhibited the proliferation and invasion of PCa cells through targeting EN2. SIGNIFICANCE: EN2 is negatively regulated by miR-605, and down-regulation of miR-605 promotes the proliferation and invasion of PCa cells by up-regulating EN2, which leads to PCa development and progression.

Isolation and identification of cancer stem cells from PC3 human prostate carcinoma cell line.

OBJECTIVE: Morphological differences of PC3 clones were dynamically observed, and the expression of CD44 in different clones was detected to compare the tumorigenic ability of different clone cells in nude mice and identify the clones containing prostate cancer stem cells. MATERIALS AND METHODS: Clone formation assay was used for observing and classifying PC3 clones and calculating the cloning efficiency and the proportion of each clone. CD44 expression in different clones was detected by immunofluorescence technique. In addition, different morphologies of clones were isolated to measure the ability of self-renewing, and inoculated into nude mice to observe the tumorigenic ability. RESULTS: PC3 cells could form three morphologies of clones, namely holoclone, meroclone, and paraclone. The cloning efficiency was 10.23%±0.91%, and the proportion of the three clones was 11.7%, 50.0% and 38.3%, respectively. Immunofluorescence showed that the expression of CD44 in holoclone was significantly stronger than meroclone and paraclone. Holoclone had self-renewing ability and strong tumorigenic ability in nude mice. CONCLUSION: There are differences in morphologies and differentiation of PC3 clones. Moreover, prostate cancer stem cells are abundant in holoclone.

MicroRNA-99a induces G1-phase cell cycle arrest and suppresses tumorigenicity in renal cell carcinoma.

BACKGROUND: A growing body of evidence suggests that microRNAs (miRNAs) play an important role in cancer diagnosis and therapy. MicroRNA-99a (miR-99a), a potential tumor suppressor, is downregulated in several human malignancies. The expression and function of miR-99a, however, have not been investigated in human renal cell carcinoma (RCC) so far. We therefore examined the expression of miR-99a in RCC cell lines and tissues, and assessed the impact of miR-99a on the tumorigenesis of RCC. METHODS: MiR-99a levels in 40 pairs of RCC and matched adjacent non-tumor tissues were assessed by real-time quantitative Reverse Transcription PCR (qRT-PCR). The RCC cell lines 786-O and OS-RC-2 were transfected with miR-99a mimics to restore the expression of miR-99a. The effects of miR-99a were then assessed by cell proliferation, cell cycle, transwell, and colony formation assay. A murine xenograft model of RCC was used to confirm the effect of miR-99a on tumorigenicity in vivo. Potential target genes were identified by western blotting and luciferase reporter assay. RESULTS: We found that miR-99a was remarkably downregulated in RCC and low expression level of miR-99a was correlated with poor survival of RCC patients. Restoration of miR-99a dramatically suppressed RCC cells growth, clonability, migration and invasion as well as induced G1-phase cell cycle arrest in vitro. Moreover, intratumoral delivery of miR-99a could inhibit tumor growth in murine xenograft models of human RCC. In addition, we also fond that mammalian target of rapamycin (mTOR) was a direct target of miR-99a in RCC cells. Furthermore, siRNA-mediated knockdown of mTOR partially phenocopied the effect of miR-99a overexpression, suggesting that the tumor suppressive role of miR-99a may be mediated primarily through mTOR regulation. CONCLUSIONS: Collectively, these results demonstrate for the first time, to our knowledge, that deregulation of miR-99a is involved in the etiology of RCC partially via direct targeting mTOR pathway, which suggests that miR-99a may offer an attractive new target for diagnostic and therapeutic intervention in RCC.