title: Long non-coding RNA MEG3 induces cell apoptosis in esophageal cancer through endoplasmic reticulum stress.
abstract: Long non-coding RNAs (lncRNAs) play important roles in diverse biological processes, such as cell growth, apoptosis and migration. Although downregulation of lncRNA MEG3 has been identified in several cancers, little is known about its role in esophageal squamous cell carcinoma (ESCC). The aim of the present study was to detect MEG3 expression in clinical ESCC tissues, investigate its biological functions and the endoplasmic reticulum (ER) stress-relative mechanism. MEG3 expression levels were detected by qRT-PCR in both tumor tissues and adjacent non-tumor tissues from 28 ESCC patients. PcDNA3.1-MEG3 recombinant plasmids were constructed and transfected to EC109 cells. Cell growth was analyzed by CCK-8 assay. Cell apoptosis was analyzed by fluorescence microscope and Annexin V/PI assay. The protein expression was determined by western blot analysis. The results showed that MEG3 decreased significantly in ESCC tissues relative to adjacent normal tissues. PcDNA3.1-MEG3 plasmids were successfully constructed and the expression level of MEG3 significantly increased after MEG3 transfection to EC109 cells. Ectopic expression of MEG3 inhibited EC109 cell proliferation and induced apoptosis in vitro. MEG3 overexpression increased the expression of ER stress‑related proteins (GRP78, IRE1, PERK, ATF6, CHOP and cleaved‑caspase-3). Our results first demonstrate that MEG3 is downregulated in ESCC tissues. MEG3 was able to inhibit cell growth and induced apoptosis in EC109 cells, most probably via activation of the ER stress pathway.
authors.affiliation: Department of Gastroenterology, Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China.
authors.forename: Zhen-Lun
authors.initials: ZL
authors.lastname: Huang
authors.affiliation: Department of Gastroenterology, Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China.
authors.forename: Rui-Pei
authors.initials: RP
authors.lastname: Chen
authors.affiliation: Department of Gastroenterology, Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China.
authors.forename: Xiao-Tao
authors.initials: XT
authors.lastname: Zhou
authors.affiliation: Department of Gastroenterology, Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China.
authors.forename: Hao-Lian
authors.initials: HL
authors.lastname: Zhan
authors.affiliation: Department of Gastroenterology, Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China.
authors.forename: Min-Min
authors.initials: MM
authors.lastname: Hu
authors.affiliation: Department of Neurosurgery, Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.affiliation: First Clinical Medical College, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.
authors.forename: Guan-Di
authors.initials: GD
authors.lastname: Wu
authors.affiliation: Department of Gastroenterology, Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China.
authors.forename: Ling-Fei
authors.initials: LF
authors.lastname: Wu
mesh_terms: D000328:Adult; D000368:Aged; D017209:Apoptosis; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015536:Down-Regulation; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress; D004938:Esophageal Neoplasms / Q000235:genetics*; D000077277:Esophageal Squamous Cell Carcinoma; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D062085:RNA, Long Noncoding / Q000235:genetics*
chemical_list: D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; C498907:MEG3 non-coding RNA, human; D062085:RNA, Long Noncoding