| Objective:To investigate the expression and function of long non-coding RNA LINC01614 in gastric cancer and its effect on the biological behavior of gastric cancer cells.Methods:1.Quantitative real-time PCR was used to identify the expression of long non-coding RNA LINC01614 in gastric cancer tissues and adjacent tissues,and gastric cancer cells and normal gastric epithelial cell.2.Bioinformatics analyses of lnc RNA LINC01614 was performed.RNASeq data downloaded from The Cancer Genome Atlas Program(TCGA)and Gene expression omnibus(GEO)were used to identify the expression of LINC01614 in gastric cancer tissues and adjacent tissues,and then the correlation between LINC01614 and clinical and pathological characteristics was analyzed by using the data of patients’ clinical information obtained from TCGA database.Then,the relationship between LINC01614 expression and patients’ overall survival was analyzed.Based on the downloaded TCGA data,the co-expression genes of LINC01614 were predicted,and the pathway enrichment was performed to predict the biological function of LINC01614 and pathways in which LINC01614 might be involved.3.si RNA was used to knockdown the expression of lnc RNA LINC01614,and the cell models were established.The experimental group with the downregulated expression of LINC01614(transfected with si-LINC01614-1,siLINC01614-2),and the control group(transfected with si-NC)were used in following study.The experimental group were that gastric cancer cells MGC-803 and AGS transfected with si-LINC01614-1 and si-LINC01614-2,while the control group were that MGC-803 and AGS transfected with si-NC.The expression of LINC01614 was identified by quantitative real-time PCR in each group.4.Lentivirus was used to transfect SGC-7901 cells to construct cells with overexpression of LINC01614 and the control group SGC-7901-NC cells,and the expression of LINC01614 was identified by quantitative real-time PCR.5.The effect of LINC01614 expression on the proliferation of gastric cancer cells was analyzed by CCK-8 assay and colony formation assay.6.Through cell wound healing assay and Transwell assay,the LINC01614’s effect of migration and invasion of gastric cancer cells was analyzed.7.The effects of LINC01614 overexpression on cell cycle distribution and apoptosis were detected by flow cytometry.Results:1.The results of quantitative real-time PCR showed that in 22 pairs of gastric cancer tissues and adjacent tissues,the relative expression of the long non-coding RNA LINC01614 in 20 pairs of gastric cancer tissues was upregulated compared with that in the paired adjacent tissues.After statistical analysis,there was significant difference of LINC01614 expression between gastric cancer tissues and the paired adjacent tissues(P < 0.0001).2.The TCGA-STAD dataset in TCGA database was downloaded and analyzed,and we found that the expression of LINC01614 was different in 27 pairs of gastric cancer tissues and adjacent tissues,while the expression of LINC01614 in gastric cancer tissues was also higher than that in adjacent tissues in the unpaired samples,and the difference was statistically significant(P < 0.05).Based on the analysis of GEO database dataset GSE95667,it was found that the expression of LINC01614 in gastric cancer tissues was also upregulated,and the log2 Fold Change was 1.953(P < 0.05).By analyzing the correlation between LINC01614 expression and the clinicopathological characteristics of patients,the high-and low-expression of LINC01614 were not correlated with the age,gender,Lauren classification,origin tumor location,cancer stage of patients with gastric cancer,N tage and M stage,but were correlated with T stage(P = 0.00187),histological grade(P = 0.0177)and residual tumor(P = 0.0218),and the correlation was statistically significant.High expression of LINC01614 related to higher T stage,histologic grade and residual tumor stage.According to the results of potential targeted m RNA of LINC01614 enrichment analysis,based on cell ontology,LINC01614 was enriched to include extracellular matrix,neutrophil activation,growth factor binding and other pathways(P < 0.05).While in KEGG analysis,the result showed that it was enriched in proven pathways enroll in gastric cancer development,including PI3K-Akt signaling pathway,Cell cycle,TGF-β signaling pathway(P < 0.05)3.By using si-LINC01614-1 and si-LINC01614-2 to knock down the expression of LINC01614,the proliferation,migration and invasion ability of MGC-803 cells and AGS cells were inhibited compared with those in the control group(P < 0.05).Meanwhile,knocking down LINC01614 expression can lead to G2/M phase arrest in cell cycle distribution(P < 0.05).However,knocking down the expression of LINC01614 did not affect the apoptosis of gastric cancer cells(P > 0.05).4.In the LINC01614 overexpression group and control group of SGC-7901 cells,the cells with LINC01614 overexpression have a reduced percentage of cells in G2/M phase compared with the control cells(P < 0.05).Cell apoptosis was detected by flow cytometry,and there was no significant difference in apoptosis between LINC01614 overexpression cells and the control group(P > 0.05).Conclusions:The expression of long non-coding RNA LINC01614 is up-regulated in gastric cancer tissues and cells,and its expression is related to the poor prognosis of gastric cancer patients.LINC01614 may participate in the development of gastric cancer as an oncogene. |
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