长链非编码RNA SOX21-AS1调控miR-31-5p/MMP-16轴对胰腺癌细胞活性与增殖的影响

Effect of long non-coding RNA SOX21-AS1 on viability and proliferation of pancreatic cancer cells via modulating miR-31-5p/MMP-16 axis

背景与目的:胰腺癌是一种常见的消化系统恶性肿瘤,也是癌症死亡的常见病因。长链非编码RNA(lncRNA)已在多种恶性肿瘤中被鉴定为调节因子和特异度生物标志物。最新研究表明,lncRNA SOX21-AS1在多种恶性肿瘤的发生、发展中起重要作用。但其在胰腺癌中的作用尚未明确。因此,本研究探讨SOX21-AS1在胰腺癌中的表达及其功能。方法:用qRT-PCR检测SOX21-AS1在20对胰腺癌与邻近癌旁正常组织,以及胰腺癌细胞系(PANC-1、CAPAN2、CFPAC-1、BXPC3、SW1990)与人胰管上皮细胞系(HPDE)中的表达。通过GEPIA数据库分析SOX21-AS1表达与胰腺癌患者预后的关系。采用MTT实验与集落形成实验分析SOX21-AS1沉默后胰腺癌细胞活力与增殖能力的变化。通过DIANA数据库预测SOX21-AS1的靶微小RNA(miRNA)及其下游的靶mRNA,随后进一步通过系列功能实验、双荧光素酶实验、拯救实验以及相关性分析明确它们之间的关系。结果:SOX21-AS1在胰腺癌组织和细胞系中表达均上调,其高表达患者预后差(均P<0.05)。SOX21-AS1沉默后,胰腺癌细胞的活力与增殖能力均明显降低(均P<0.05)。生物信息学分析显示,miR-31-5p与SOX21-AS1及MMP-16 mRNA均存在靶向结合序列,功能实验、荧光素酶实验及挽救实验结果均验证了三者之间的互作关系。此外,相关性分析结果显示,SOX21-AS1的表达与miR-31-5p的表达呈负相关(r^(2)=0.2571,P<0.05),miR-31-5p的表达与MMP-16 mRNA的表达呈负相关(r^(2)=0.3113,P=0.0106)。结论:SOX21-AS1的表达上调与胰腺癌细胞活性、增殖能力增强及胰腺癌患者预后不良相关。机制上,SOX21-AS1可能作为竞争性内源RNA(ceRNA)与miR-31-5p发生竞争性结合,调节MMP-16的表达,从而促进胰腺癌的进展。SOX21-AS1可以作为胰腺癌的潜在预后生物标志物和诊治的靶点。

Background and Aims:Pancreatic cancer is a common tumor of the digestive system and a frequent cause of cancer-related death.Long non-codingRNAs(lncRNAs)have been demonstrated as regulators and specific biomarkers for multiple cancers.Recent evidence has indicated that the novel lncRNA SOX21-AS1 plays an important role in the initiation and progression of a variety of malignant tumors.However,its function in pancreatic cancer remains unclear.Therefore,this study was conducted to investigate the expression of SOX21-AS1 in pancreatic cancer and its function.Methods:The expressions of SOX21-AS1 in 20 pairs of specimens of pancreatic cancer and adjacent normal tissue as well as in a range of pancreatic cancer cell lines(PANC-1,CAPAN2,CFPAC-1,BXPC3,and SW1990)and human pancreatic duct epithelial cell line(HPDE)were detected by qRT-PCR method.The relationship between SOX21-AS1 expression and the prognosis of pancreatic cancer patients were analyzed through GEPIA database.The changes in cell viability and proliferative capacity in pancreatic cancer cells after SOX21-AS1 silencing were determined by MTT assay and colonyforming assay.The targeted microRNAs(miRNAs)of SOX21-AS1 and its downstream targeted mRNAs were predicted using DIANA database,and then the interactions among them were validated by a series of function experiments,dual luciferase reporter assays,rescue experiments and correlation analyses.Results:The expressions of SOX21-AS1 were upregulated in both pancreatic cancer tissue and cell lines,and the patients with its high expression had a poor prognosis(all P<0.05).In pancreatic cancer cells after SOX21-AS1 silencing,the cell viability and proliferative ability were significantly decreased(both P<0.05).Bioinformatics analysis indicated that there was a target binding sequence in miR-31-5p for both SOX21-AS1 and MMP-16 mRNA,and the interactions among them were confirmed by function experiments,dual luciferase reporter assays and rescue experiments.In addition,the results of correlation analysis showed that there was a negative correlation either between SOX21-AS1 expression and miR-31-5p expression(r^(2)=0.2571,P<0.05),or between miR-31-5p expression MMP-16 mRNA expression(r^(2)=0.3113,P=0.0106).Conclusion:The increased expression of SOX21-AS1 is associated with the enhanced viability and proliferation of pancreatic cancer cells,as well as the poor prognosis of pancreatic cancer patients.In terms of mechanism,SOX21-AS1 may competitively bind to miR-31-5p as a competing endogenousRNA(ceRNA)to regulate the expression of MMP-16 mRNA,thereby promoting the progression of pancreatic cancer.SOX21-AS1 may probably be a potential biomarker and therapeutic target for pancreatic cancer.