A single nucleotide variant in microRNA-1269a promotes the occurrence and process of hepatocellular carcinoma by targeting to oncogenes SPATS2L and LRP6

Hepatocellular carcinoma (HCC) is one of the malignant and lethal cancers. Single nucleotide polymorphisms (SNPs) in microRNAs(miRNAs) can affect the expression and target identification of miRNAs and lead to the formation of malignant tumors. However, little is known about whether microRNA-1269a (miR-1269a) SNPs affect the susceptibility and progression of HCC or their specific mechanism. The association between microRNA-1269a rs73239138 and the susceptibility to HCC was verified by MassARRAY assay in a large case-control sample. The effect of miR-1269a and the variant on the proliferation and apoptosis of HCC cells was examined by flow cytometry (FCM), CCK8 assay and Western blot. The target of miR-1269a was identified by bioinformatics analysis and qRT-PCR and its role on cell proliferative capacity was examined by CCK8 assay. The expression level of miR-1269a was analyzed by qRT-PCR in HCC cells transfected with wild or variant type pre-miR-1269a plasmid. MiR-1269a produced a tumor suppressor effect by inhibiting cell proliferation and inducing apoptosis of human HCC cells, possibly via inhibiting the expression of its target genes SPATS2L and LRP6, which were tumor promoters. While, rs73239138 (G > A) in miR-1269a reduced the anticancer effect of miR-1269a possibly by attenuating its total amount in HCC cells or its target recognition, reduce its inhibition on target genes and promoted the susceptibility to HCC. Our findings for the first time proved that miR-1269a SNP plays a role in the occurrence and process of HCC and the relevant mechanism, in accompany with the discovery of the novel target genes of miR-1269a.

肝细胞癌（HCC）是恶性且致命的癌症之一。微小RNA（miRNAs）中的单核苷酸多态性（SNPs）会影响miRNAs的表达和靶标识别，并导致恶性肿瘤的形成。然而，关于微小RNA - 1269a（miR - 1269a）的SNPs是否影响HCC的易感性和进展及其具体机制，人们知之甚少。通过MassARRAY分析在大量病例 - 对照样本中验证了微小RNA - 1269a rs73239138与HCC易感性之间的关联。通过流式细胞术（FCM）、CCK8检测和蛋白质印迹法检测了miR - 1269a及其变体对HCC细胞增殖和凋亡的影响。通过生物信息学分析和实时定量聚合酶链反应（qRT - PCR）确定了miR - 1269a的靶标，并通过CCK8检测其对细胞增殖能力的作用。通过qRT - PCR分析在转染野生型或变异型pre - miR - 1269a质粒的HCC细胞中miR - 1269a的表达水平。MiR - 1269a通过抑制细胞增殖和诱导人HCC细胞凋亡产生肿瘤抑制作用，可能是通过抑制其靶基因SPATS2L和LRP6（肿瘤促进因子）的表达来实现的。然而，miR - 1269a中的rs73239138（G > A）可能通过降低其在HCC细胞中的总量或其靶标识别能力，减弱了miR - 1269a的抗癌作用，降低了其对靶基因的抑制，并增加了对HCC的易感性。我们的研究结果首次证明了miR - 1269a SNP在HCC的发生和发展过程中起作用以及相关机制，同时发现了miR - 1269a的新靶基因。