Background: Single nucleotide polymorphisms (SNPs) located in the 3'-UTR of miRNA target genes could affect miRNA-mediated gene regulation, thereby contributing to the susceptibility or prognosis of cancer. Accordingly, the present study analyzed SNPs located at putative miRNA-binding sites of the 3'-UTR of various genes and investigated their impact on the prognosis for patients with colorectal cancer.
Materials and methods: In total, 831 consecutive patients (discovery cohort, n = 309; validation cohort, n = 522) with curatively resected colorectal adenocarcinoma were enrolled. Plus, 157 SNPs were selected from an in silico analysis based on several miRNA and HapMap databases. The SNP genotyping was performed using a Sequenom MassARRAY. A luciferase assay was used to investigate whether miR-571 modulated PAUF gene expression when rs12373 was included in the PAUF 3'UTR region.
Results: In the discovery cohort, 18 SNPs were identified as possible prognostic biomarkers in a survival analysis. In the validation cohort, two SNPs (TPST1 rs3757417T>G and PAUF rs12373A>C) were significantly associated with prognosis in the same direction as the discovery cohort when adjusted for age, preoperative carcinoembryonic antigen level, and pathologic stage (discovery + validation cohort; TPST1 rs3757417T>G, disease-free survival (DFS), p value = 0.0004, overall survival (OS), p value = 0.01 in recessive model; PAUF rs12373A>C, DFS, p value = <0.0001, OS, p value = 0.0008 in dominant model). A significantly lower Renilla activity was observed in the rs12373 CC construct when compared with the rs12373 AA construct (p = 0.002).
Conclusion: The current study provides evidence that the TPST1 rs3757417T>G and PAUF rs12373A>C polymorphisms are possible prognostic biomarkers for patients with colorectal cancer.