Expression and mechanisms of long non-coding RNA genes MEG3 and ANRIL in gallbladder cancer

Abstract

The objective of this study was to investigate the expression, proliferation, and apoptosis function of long-chain non-coding RNA maternally expressed gene 3 (MEG3) and antisense non-coding RNA at the INK4 locus (ANRIL) in gallbladder cancer (GBC) tissues. GBC tissues and adjacent normal samples were collected from 84 patients from January 2008 to June 2010. Empty vector, pcDNA-MEG3, and pcDNA-ANRIL vectors were transfected into GBC-SD and QBC939 cells. An MTT assay, real-time quantitative polymerase chain reaction (RT-qPCR), flow cytometry, Western blotting, and immunohistochemistry were applied. The effects of MEG3 and ANRIL were also verified in mice. Compared with normal tissues, the expression of MEG3 was significantly lower in GBC tissues, whereas the expression of ANRIL was significantly higher (both P < 0.05). The overexpression of MEG3 and underexpression of ANRIL were significantly associated with GBC prognosis (both P < 0.05). The expressions of MEG3 and ANRIL were higher in pcDNA-MEG3 and pcDNA-ANRIL-transfected cells than in empty vector-transfected cells in vitro (both P < 0.05). Most of the pcDNA-MEG3-transfected cells were in the G0-G1 phase, which showed reduced cell activity and clone counts and increased p53 and decreased cyclin D1, whereas the pcDNA-ANRIL-transfected cells were mostly in the S phase and showed contrasting behavior. Mice injected with pcDNA-MEG3-transfected cells had smaller and lighter tumors, decreased ki-67 levels, and increased caspase 3 levels, whereas those injected with pcDNA-ANRIL showed contrasting results (all P < 0.05). MEG3 can inhibit the proliferation of GBC cells and promote apoptosis, whereas ANRIL can improve the proliferation of gallbladder cells and inhibit apoptosis. Collectively, our results suggest that therapeutic strategies directed toward upregulating MEG3 and downregulating ANRIL may be clinically relevant for the inhibition of GBC deterioration.

Noncoding RNAs in Gallbladder Cancer

“…pcDNA-MEG3 plasmid transfection in GBC cells induced the accumulation of p53 protein and reduction of the cyclin D1 gene expression. These transfected cell lines showed an accumulation of cells at the G0/G1 phase, lower expression levels of ki-67, and higher expression levels of Caspase-3, which implies that MEG3 also plays a vital role in the induction of apoptosis in GBC [29]. …”

“…The role of lncRNA ANRIL in the pathogenesis of GBC was studied by Liu et al together with that of MEG3 mentioned before [29]. In that study, GBC tissues and adjacent normal samples were collected from 84 patients, and empty vector and pcDNA-ANRIL vectors were transfected into GBC-SD and QBC939 cells.…”

“…Regarding MEG3, Liu et al demonstrated an approximately 6.25-fold reduction in its expression in GBC tissues compared to normal tissue samples [29]. The transfection of pcDNA-MEG3 plasmids in human GBC GBC-SD and QBC939 cell lines resulted in reduced tumorigenic potential.…”

“…Even if mice injected with pcDNA-ANRIL showed contrasting results, the authors concluded that ANRIL can improve the proliferation of gallbladder cells and inhibit apoptosis [29].…”

MEG3 long non-coding RNA prevents cell growth and metastasis of osteosarcoma

“…Zhu et al suggested that MEG3 functions as a tumor suppressor in hepatoma cells through interacting with p53 protein (18). In addition to these studies, the role of MEG3 has been investigated in gallbladder cancer, NSCLC, neuroendocrine tumor, gastric cancer, thyroid carcinoma and so on (25,(14)(15)(16)(17). However, to the best of our knowledge, the potential roles of MEG3 in OS remain largely unknown.…”