S Y Lee1, J E Choi2, H S Jeon3, M J Hong4, Y Y Choi4, H G Kang4, S S Yoo1, E B Lee5, J Y Jeong6, W K Lee7, J Lee8, S I Cha8, C H Kim8, Y T Kim9, S Jheon9, J W Son10, J Y Park11. 1. Lung Cancer Center, Kyungpook National University Medical Center, Daegu; Department of Internal Medicine, School of Medicine, Kyungpook National University, Daegu. 2. Lung Cancer Center, Kyungpook National University Medical Center, Daegu; Department of Biochemistry and Cell Biology, School of Medicine. Electronic address: jechoi.9711@gmail.com. 3. The Molecular Diagnostics & Imaging Research Institute. 4. Department of Biochemistry and Cell Biology, School of Medicine. 5. Departments of Thoracic Surgery. 6. Pathology. 7. Biostatistics Center, School of Medicine, Kyungpook National University, Daegu. 8. Department of Internal Medicine, School of Medicine, Kyungpook National University, Daegu. 9. Department of Thoracic and Cardiovascular Surgery, Seoul National University School of Medicine, Seoul. 10. Department of Internal Medicine, Konyang University Hospital, Daejeon. 11. Lung Cancer Center, Kyungpook National University Medical Center, Daegu; Department of Internal Medicine, School of Medicine, Kyungpook National University, Daegu; Department of Biochemistry and Cell Biology, School of Medicine; BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, Kyungpook National University, Daegu, Republic of Korea.
Abstract
BACKGROUND: MicroRNAs (miRNAs) have a key role in carcinogenesis through negative regulation of their target genes. Therefore, genetic variations in miRNAs or their target sites may affect miRNA-mRNA interactions, thereby result in altered expression of target genes. This study was conducted to investigate the associations between single-nucleotide polymorphisms (SNP) located in the miRNA target sites (poly-miRTSs) and survival of patients with early-stage non-small-cell lung cancer (NSCLC). METHODS: Using public SNP database and miRNA target sites prediction program, 354 poly-miRTSs were selected for genotyping. Among these, 154 SNPs applicable to Sequenom's MassARRAY platform were investigated in 357 patients. A replication study was carried out on an independent patient population (n = 479). Renilla luciferase assay and reverse transcription-polymerase chain reaction were conducted to examine functional relevance of potentially functional poly-miRTSs. RESULTS: Of the 154 SNPs analyzed in a discovery set, 14 SNPs were significantly associated with survival outcomes. Among these, KRT81 rs3660G>C was found to be associated with survival outcomes in the validation cohort. In the combined analysis, patients with the rs3660 GC + CC genotype had a significantly better overall survival compared with those with GG genotype [adjusted hazard ratio (aHR) for OS, 0.65; 95% confidence interval (CI) 0.50-0.85; P = 0.001]. An increased expression of the reporter gene for the C allele of rs3660 compared with the G allele was observed by luciferase assay. Consistently, the C allele was associated with higher relative expression level of KRT81 in tumor tissues. CONCLUSION: The rs3660G>C affects KRT81 expression and thus influences survival in early-stage NSCLC. The analysis of the rs3660G>C polymorphism may be useful to identify patients at high risk of a poor disease outcome.
BACKGROUND: MicroRNAs (miRNAs) have a key role in carcinogenesis through negative regulation of their target genes. Therefore, genetic variations in miRNAs or their target sites may affect miRNA-mRNA interactions, thereby result in altered expression of target genes. This study was conducted to investigate the associations between single-nucleotide polymorphisms (SNP) located in the miRNA target sites (poly-miRTSs) and survival of patients with early-stage non-small-cell lung cancer (NSCLC). METHODS: Using public SNP database and miRNA target sites prediction program, 354 poly-miRTSs were selected for genotyping. Among these, 154 SNPs applicable to Sequenom's MassARRAY platform were investigated in 357 patients. A replication study was carried out on an independent patient population (n = 479). Renilla luciferase assay and reverse transcription-polymerase chain reaction were conducted to examine functional relevance of potentially functional poly-miRTSs. RESULTS: Of the 154 SNPs analyzed in a discovery set, 14 SNPs were significantly associated with survival outcomes. Among these, KRT81 rs3660G>C was found to be associated with survival outcomes in the validation cohort. In the combined analysis, patients with the rs3660 GC + CC genotype had a significantly better overall survival compared with those with GG genotype [adjusted hazard ratio (aHR) for OS, 0.65; 95% confidence interval (CI) 0.50-0.85; P = 0.001]. An increased expression of the reporter gene for the C allele of rs3660 compared with the G allele was observed by luciferase assay. Consistently, the C allele was associated with higher relative expression level of KRT81 in tumor tissues. CONCLUSION: The rs3660G>C affects KRT81 expression and thus influences survival in early-stage NSCLC. The analysis of the rs3660G>C polymorphism may be useful to identify patients at high risk of a poor disease outcome.