MicroRNA Binding Site Polymorphisms of the Long-Chain Noncoding RNA MALAT1 are Associated with Risk and Prognosis of Colorectal Cancer in Chinese Han Population

Background: The metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) gene rs664589 locus is located in the binding site of the long-chain noncoding RNA (lncRNA) MALAT1 with hsa-miR-194-5p. The aim of this study was to investigate the association between the rs664589 single nucleotide polymorphism (SNP) and the risk and prognosis of colorectal cancer (CRC) in the Chinese Han population. Methods: A cohort of 340 patients with CRC who underwent surgical resection and another group of 340 healthy subjects were enrolled in this study and analyzed for their rs664589 genotypes. In addition, quantitative real-time-polymerase chain reaction was used to detect the expression levels of the lncRNA MALAT1 and the hsa-miR-194-5p in cancer tissues and paracancerous normal tissues of CRC patients. Results: The risk of CRC in subjects carrying the G allele at the rs664589 locus in the 3 ' untranslated region of the MALAT1 gene was 1.81 times higher than for C allele carriers. The expression levels of the lncRNA MALAT1 in cancer tissues was significantly higher than that in paracancerous tissues, while the hsa-miR-194-5p expression level was significantly lower in cancerous tissues compared to cognate paracancerous tissues. The progression-free survival (PFS) rate patients with the MALAT1 gene rs664589 locus GG genotype was significantly lower than that of CG genotype patients. Moreover, lncRNA MALAT1 inhibited the expression of hsa-miR-194-5p. Conclusion: The risk of CRC was relatively higher in MALAT1 rs664589 G allele carriers, and the CRC patients with a G allele had a lower PFS. The possible mechanism is that the rs664589 SNP affects the binding efficiency of lncRNA MALAT1 and hsa-miR-194-5p, although the specific mechanism responsible needs to be further evaluated for confirmation.