Long Non-Coding RNA MEG3 Inhibits Cell Proliferation and Induces Apoptosis in Prostate Cancer

Abstract

Background/Aims: Long non-coding RNAs (lncRNAs) play important roles in diverse biological processes, such as cell growth, apoptosis and migration. Although downregulation of lncRNA maternally expressed gene 3 (MEG3) has been identified in several cancers, little is known about its role in prostate cancer progression. The aim of this study was to detect MEG3 expression in clinical prostate cancer tissues, investigate its biological functions in the development of prostate cancer and the underlying mechanism. Methods: MEG3 expression levels were detected by qRT-PCR in both tumor tissues and adjacent non-tumor tissues from 21 prostate cancer patients. The effects of MEG3 on PC3 and DU145 cells were assessed by MTT assay, colony formation assay, western blot and flow cytometry. Transfected PC3 cells were transplanted into nude mice, and the tumor growth curves were determined. Results: MEG3 decreased significantly in prostate cancer tissues relative to adjacent normal tissues. MEG3 inhibited intrinsic cell survival pathway in vitro and in vivo by reducing the protein expression of Bcl-2, enhancing Bax and activating caspase 3. We further demonstrated that MEG3 inhibited the expression of cell cycle regulatory protein Cyclin D1 and induced cell cycle arrest in G0/G1 phase. Conclusions: Our study presents an important role of MEG3 in the molecular etiology of prostate cancer and implicates the potential application of MEG3 in prostate cancer therapy.

Elevated Expression Levels of Long Non-Coding RNA, Loc554202, Are Predictive of Poor Prognosis in Cervical Cancer

“…lncRNAs constitute a heterogeneous group of RNA molecules in eukaryotic cells and play a role in a wide variety of biological processes (Hanahan and Weinberg 2000). Previous studies have shown that expression of several lncRNAs is dysregulated in cancer tissues, such as MEG3 (Luo et al 2015), CCHE1 (Yang et al 2015), and HOTAIR (Ding et al 2015). In the present study, high levels of Loc554202 were observed in cervical cancer tissues compared with the surrounding non-tumor cervical tissues.…”

Comprehensive site-specific whole genome profiling of stromal and epithelial colonic gene signatures in human sigmoid colon and rectal tissue

“…A total of 205 lncRNAs (Supplemental Tables S3 and S4) were identified in the stroma/epithelial compartments associated with the sigmoid colon and rectum. The stroma was particularly enriched in lncRNAs linked to cancer and embryogenesis, e.g., FENDRR (17a, 58) and MEG3 (34,38,61). Interestingly, with respect to sigmoidal and rectal tissue distribution, HOTAIRM1, a potential prognostic marker of colorectal cancer (32,51), was predominantly expressed in the rectum.…”

MEG3 inhibits proliferation and invasion and promotes apoptosis of human osteosarcoma cells

“…MEG3 is expressed in many human normal tissues, but has failed to express in a variety of human tumour cells, such as non-small cell lung cancer, bladder cancer, prostate cancer and other cancers (9)(10)(11)(12)(13)(14). Additionally, many studies have articulated that MEG3 gene plays an inhibiting role in various tumour cells (15)(16)(17)(18)(19)(20). However, the functional mechanism of MEG3 in MG63 has yet to be proven.…”