Long Non-coding RNA SNHG20 Promotes Non-small Cell Lung Cancer Cell Proliferation And Migration By Epigenetically Silencing Of P21 Expression

Background: Mounting evidence demonstrates that long non-coding RNAs(lnc RNAs)are novel transcripts governing multiple biologicalprocesses,and their dysregulation is involved in the development and progression of multiple types of cancers.Small Nucleolar RNA Host Gene 20(SNHG20)is a 2183 bp lnc RNA,and its overexpression predicts poor prognosis in colorectal cancer and hepatocellular carcinoma.However,the clinical relevance of SNHG20 and its molecular mechanisms affecting cancer cell phenotype have not been documented.Objective: To investigate the biological function and molecular mechanism of long non-coding RNA SNHG20 in NSCLC.Methods:(1)Expression of SNHG20 in NSCLC tissues was analyzed by TCGA database.(2)Real time fluorescence quantitative PCR was used to detect the relative expression of SNHG20 in the cancer tissue and the adjacent tissues and cell lines.(3)In vitro experiments(MTT,clonogenic assay,Ed U assay,flow cytometry,etc.)were conducted to evaluate the effect of SNHG20 on the proliferation of NSCLC cells.(4)In vivo experiments(nude mice transplanted tumor model)were used to study the effect of SNHG20 on the tumorigenic ability of NSCLC cells in vivo.(5)High throughput transcriptome sequencing was used to identify target genes for downstream regulation of SNHG20,and q RT-PCR and Western blot were used to validate the sequencing results.(6)RNA immunoprecipitation assay and chromatin immunoprecipitation assay were used to study the molecular mechanism of SNHG20 regulating target gene P21.(7)Rescue assays were performed to verify the regulation of SNHG20 to P21.Results: The expression of SNHG20 was up-regulated in NSCLC tissues,and high SNHG20 expression levels were significantly correlated with tumor size,TNM stage and poor prognosis.Downregulation of SNHG20 significantly inhibited the proliferation of NSCLC cells,induced apoptosis,and cell cycle arrest in G1/G0 phase.The mechanism was that SNHG20 interacted with EZH2,regulating the expression of target gene P21 in an epigenetic way,and played a role similar to oncogene.Conclusion: SNHG20 played the role of oncogene in NSCLC and inhibits the expression of SNHG20 to significantly inhibit the growth of cancer cells.SNHG20 could be used as a potential new target for the diagnosis and treatment of NSCLC.