TCONS 00090092 MEG3
MEG3, Maternally Expressed 3 is a long noncoding RNA gene that has been demonstrated to be a tumour suppressor in many malignancies.
Approved symbol: MEG3
Approved name: maternally expressed 3
HGNC ID: HGNC:14575
Previous names: maternally expressed 3; maternally expressed 3 (non-protein coding)
Alias symbols: GTL2; NCRNA00023; LINC00023; onco-lncRNA-83
Alias names: non-protein coding RNA 23; long intergenic non-protein coding RNA 23
RefSeq ID: NR_002766
MEG3 is an imprinted gene maternally expressed in humans that encodes a long non-coding RNA of ∼1700 nucleotides.  MEG3 is located at 14q32.3. Although a location for a tumor suppressor gene has been hypothesized in this region because it is frequently lost in cholangiocarcinoma or neuroblastoma, no protein-coding gene has been identified so far at this site.  There are 12 different MEG3 gene transcripts, generated by alternative splicing. They contain the common exons 1-3 and exons 8-10, but each uses one or more exons 4-7 in a different combination in the middle. MEG3 isoform expression patterns are tissue and cell type specific.
MEG3 functions an important role in the regulation of proper cell growth and embryo development and therefore may be a putative tumor suppressor gene, because one of its functions is to activate p53 and inhibit cell proliferation.  MEG3 can also control gene expression at imprinted loci through recruitment of the polycomb repressive complex 2 (PRC2). 
Through studies, a functional tissue-specific mechanism of regulation of MEG3 expression via microRNA-29a-dependent regulation of promoter methylation was reported. Overexpression of mir-29a increased expression of MEG3. 
The aberrant expression of this lncRNA has been linked to hepatoblastoma development. Microarray analysis revealedMEG3 was downregulated by 210-fold in in malignant hepatocytes relative to expression in non-malignant hepatocytes. MEG3 expression was markedly reduced in four human hepatocellular cancer (HCC) cell lines compared with normal hepatocytes by real-time PCR. RNA In situhybridization showed intense cytoplasmic expression of MEG3 in non-neoplastic liver with absent or very weak expression in HCC tissues. 
|Experiment||Forward primer||Reverse primer|
|qRT-PCR||5'-ACACTTGCTGTCTTCCTT- 3'||5'-CCAGGTCAGGAACTTTGT- 3'|
>gi|55384|ref|NR_046470.2| Homo sapiens maternally expressed 3 (MEG3), transcript variant 13, long non-coding RNA
- Neuroendocrine Unit and the Neuropathology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
- Department of Pathology, Hôpital Beaujon, AP-HP, 92110 Clichy, France
- College of Medicine, and the Ohio State University Comprehensive Cancer Center, Ohio State University, Columbus, OH, USA
- Mayo Clinic, Jacksonville, FL, USA
- Department of Pediatric Surgery, Children's Hospital of Fudan University and The Key Laboratory of Neonatal Disease, Chinese Ministry of Health, Shanghai, China
- Zhou, Y., Zhong, Y., Wang, Y., Zhang, X., Batista, D. L., Gejman, R., ... & Klibanski, A. Activation of p53 by MEG3 non-coding RNA[J]. Journal of Biological Chemistry. 2007,282(34): 24731-24742.
- Cazals-Hatem D, Rebouissou S, Bioulac-Sage P, Bluteau O, Blanché H, Franco D et al. Clinical and molecular analysis of combined hepatocellular-cholangiocarcinomas[J]. Journal of Hepatology. 2004,41(2):292-298.
- Zhang X, Rice K, Wang Y, Chen W, Zhong Y, Nakayama Y et al. Maternally expressed gene 3 (MEG3) noncoding ribonucleic acid: isoform structure, expression, and functions[J]. Endocrinology. 2010,151(3):939-947.
- Prensner JR & Chinnaiyan AM. The emergence of lncRNAs in cancer biology[J]. Cancer discovery. 2011, 1(5):391-407.
- Braconi C, Kogure T, Valeri N, Huang N, Nuovo G, Costinean S et al. microRNA-29 can regulate expression of the long non-coding RNA gene MEG3 in hepatocellular cancer[J]. Oncogene. 2011,30:4750-4756.
- Dong R, Jia D, Xue P, Cui X, Li K, Zheng S et al. Genome-wide analysis of long noncoding RNA (lncRNA) expression in hepatoblastoma tissues[J]. Plos One. 2014, 9(1):e85599-e85599.
- Ma L, Wang F, Du C, et al. Long non-coding RNA MEG3 functions as a tumour suppressor and has prognostic predictive value in human pancreatic cancer[J]. Oncology reports. 2018,39(3):1132-1140.