长链非编码RNA 909靶向调控miR-194-5p/DACH1轴对胰腺癌细胞增殖、迁移和侵袭的影响

背景与目的:长链非编码RNA 909(LINC00909)是一个新发现的长度约为2 kb的长链非编码RNA(lncRNA),在胶质瘤和白血病中被报道发挥癌基因的作用.然而LINC00909在胰腺癌中的作用鲜有报道.本研究旨探讨LINC00909在胰腺癌中的表达及其对患者预后的影响,以及LINC00909与其调控网络对胰...

Effect of long non-coding RNA 909 on proliferation, migration, and invasion of pancreatic cancer cells by targeting regulation of miR-194-5p/DACH1 axis

Background and Aims Long non-coding RNA 909 (LINC00909) is a newly discovered long non-coding RNA (lncRNA) with a length of approximately 2 kb, which has been reported to function as an oncogene in gliomas and leukemias. However, the role of LINC00909 in pancreatic cancer has rarely been reported. This study was designated to investigate the expression of LINC00909 in pancreatic cancer and its influence on prognosis of the patients, as well as the impacts of LINC00909 and its regulatory network on the biological behaviors in pancreatic cancer cells.Methods The expressions of LINC00909 in 24 different types of cancers in TCGA datasets were analyzed through UALCAN. LinkedOmics was used to analyze the expressions of LINC00909 and prognosis in 176 pancreatic cancer patients were analyzed through LinkedOmics database. By using the lncRNA-miRNA binding database (starBase) and three miRNA-mRNA binding databases (miRmap, miRanda, and TargetScan), the potential target microRNAs (miRNAs) of LINC00909 and the mRNAs downstream to these miRNAs were predicted, and the LINC00909-miRNA-mRNA network was constructed. The differentially expressed miRNAs between pancreatic cancer and adjacent non-tumorous pancreatic tissues were identified by the "limma" package of R language. The survival analysis and correlation analysis were conducted by using "survival", "survminer", and "ggstatsplot" packages in R language. In pancreatic cancer PANC-1 cells, the influences of LINC00909 on cell proliferation, and migration/invasion abilities were investigated by a knockdown experiment (LINC00909 siRNA transfection), and the targeted relationship between LINC00909 and the potential miRNAs were verified by a rescue experiment (simultaneous transfection of LINC00909 siRNA and miRNA inhibitor). The interactions of the target miRNAs and with LINC00909 and their downstream mRNAs were verified by dual luciferase reporter assay.Results UALCAN analysis revealed that LINC00909 was lowly expressed in pancreatic cancer tissues. Low expression of LINC00909 predicted poor prognosis based on data from LinkedOmics databases (P<0.05). A total of 28 miRNAs potentially binding to LINC00909 were obtained through the starBase. Further analysis of the miRNA expression data in pancreatic cancer from TCGA found that only miR-194-5p was significantly up-regulated in pancreatic cancer. Using the target prediction databases miRmap, miRanda and TargetScan databases, 114 potential downstream target mRNAs of miR-194-5p were obtained. After further expression correlation analysis and survival analysis of the 114 mRNAs, 4 mRNAs (DACH1, SOCS2, STX16 and SNAP91) were identified. Finally, the ceRNA network of LINC00909-miR-194-5p-DACH1/SOCS2/STX16/SNAP91 was obtained. Results of knockdown experiment showed that the proliferation activity, scratch healing rate and the numbers of migrated and invaded cells were significantly higher in LINC00909 low expression group than those in control group (all P<0.05). Results of rescue experiment showed that the expression level of DACH1 mRNA was significantly increased, while and the cell proliferation activity, scratch healing rate, and the numbers of migrated and invaded cells were significantly decreased in rescue group compared with those in LINC00909 low expression group (all P<0.05). Results of dual luciferase reporter assay showed that miR-194-5p mimics significantly suppressed the luciferase activity of the LINC00909 and DACH1 reporter plasmid containing binding sites (both P<0.05).Conclusion Expression of LINC00909 is decreased in pancreatic cancer tissue and it exerts a tumor suppressor function. It may inhibit the proliferation, migration, and invasion of pancreatic cells by targeting and regulating the miR-194-5p/DACH1 axis.