Corrigendum: The authors found errors in our published article: Quantitative Analysis of Cancer-associated Gene Methylation Connected to Risk Factors in Korean Colorectal Cancer Patients / 예방의학회지

On pages 252, 253, 254, Method, Table 1 and Figure 1 have been misspelled. The reverse transcriptase should be corrected as 'realtime'.

Quantitative Analysis of Cancer-associated Gene Methylation Connected to Risk Factors in Korean Colorectal Cancer Patients / 예방의학회지

OBJECTIVES: The purpose of this paper was to elucidate the potential methylation levels of adjacent normal and cancer tissues by comparing them with normal colorectal tissues, and to describe the correlations between the methylation and clinical parameters in Korean colorectal cancer (CRC) patients. METHODS: Hypermethylation profiles of nine genes (RASSF1, APC, p16INK4a, Twist1, E-cadherin, TIMP3, Smad4, COX2, and ABCB1) were examined with 100 sets of cancer tissues and 14 normal colorectal tissues. We determined the hypermethylation at a given level by a percent of methylation ratio value of 10 using quantitative methylation real-time polymerase chain reaction. RESULTS: Nine genes' hypermethylation levels in Korean CRC patient tissues were increased more higher than normal colorectal tissues. However, the amounts of p16INK4a and E-cadherin gene hypermethylation in normal and CRC tissues were not significantly different nor did TIMP3 gene hypermethylation in adjacent normal and cancer tissues differ significantly. The hypermethylation of TIMP3, E-cadherin, ABCB1, and COX2 genes among other genes were abundantly found in normal colorectal tissues. The hypermethylation of nine genes' methylation in cancer tissues was not significantly associated with any clinical parameters. In Cohen's kappa test, it was moderately observed that RASSF1 was related with E-cadherin, and Smad4 with ABCB1 and COX2. CONCLUSIONS: This study provides evidence for different hypermethylation patterns of cancer-associated genes in normal and CRC tissues, which may serve as useful information on CRC cancer progression.

Association Between MicroRNA196a2 rs11614913 Genotypes and the Risk of Non-Small Cell Lung Cancer in Korean Population / 예방의학회지

OBJECTIVES: The microRNA (miRNA) miR-196a2 may play an important role in lung cancer development and survival by altering binding activity of target mRNA. In this study, we evaluated their associations with the susceptibility of non-small cell lung cancers (NSCLC) by case-control study in a Korean population. METHODS: We performed genotyping analyses for miR-196a2 rs11614913 T/C at miRNA regions in a case-control study using blood samples of 406 NSCLC patient and 428 cancer-free control groups. RESULTS: The total C allele frequencies for miR-196a2 were 48.8% for the patients and 45.6% for the controls; and the genotype frequencies of TT, TC, and CC were 23.7%, 55.2%, and 21.1% for the patients and 31.1%, 46.35%, and 22.4% for the controls (p<0.05). Participants who possesses TC/CC genotypes showed high risk for NSCLC compared to those possessed TT genotypes (OR, 1.42; 95% CI, 1.03 to 1.96). The association was persisted in 60 and older age group, male, smokers, those without family history for cancer. However, no significant association of CC genotypes in recessive genetic model was observed. CONCLUSIONS: In conclusion, this case-control study provides evidence that miR-196a2 rs11614913 C/T polymorphisms are associated with a significantly increased risk of NSCLC in a dominant model, indicating that common genetic polymorphisms in miR-196a2 rs11614913 are associated with NSCLC. The association of miR196a2 rs11614913 polymorphisms and NSCLC risk require confirmation through additional larger studies.

No Association Between Functional Polymorphisms in COMT and MTHFR and Schizophrenia Risk in Korean Population / 한국역학회지

OBJECTIVES: Common genetic SNPs in two genes, encoding catechol-O-methyltransferase (COMT) and methylenetetrahydrofolate reductase (MTHFR), which are interconnected with COMT gene regulation, have been reported to contribute to schizophrenia risk. In this study, we evaluated the association between functional polymorphisms in COMT and MTHFR and schizophrenia risk with a case-control study in a Korean population. METHODS: We performed a case-control study by genotyping analysis using 360 cases and 348 controls in Korean subjects to determine the association between functional polymorphisms in COMT and MTHFR and schizophrenia risk. RESULTS: Four functional SNPs in COMT (Val158Met and rs165599) and MTHFR (C677T and A1298C) were genotyped by primer extension assay. None of the genotype distributions for the four SNPs was significantly different between cases and controls. Stratified analysis did not show any significant gender difference for any polymorphism. In addition, we found no evidence of a gene-gene interaction in the analysis of combined genotypes. CONCLUSION: Our results suggest no significant association between the selected functional polymorphisms of COMT or MTHFR in Korean schizophrenia subjects. However, further studies are required to confirm our findings in a larger number of subjects.

Analysis of Single Nucleotide Polymorphisms of COMT Gene in Korean Schizophrenics / 신경정신의학

OBJECTIVES: Catechol-O-methyltransferase (COMT) plays an important role in metabolizing catecholamines, including dopamine. Also, several single-nucleotide polymorphisms (SNPs) of the COMT gene are associated with schizophrenia. Therefore, this study aimed to find the association between COMT gene SNPs and schizophrenia in Koreans. METHODS: Participants were 366 schizophrenia patients and 359 normal controls. To identify the SNPs, we performed genetic analyses in 4 SNP regions, via SNP-ITTM assays. We compared allele, genotype, and haplotype frequencies between the two groups. Moreover, we built subgroups, based on onset age, and compared individual allele and genotype frequencies among these subgroups. RESULTS: In female patients, genotype frequencies showed a significant difference in rs2020917 among the 4 SNPs (p=0.0224), but haplotype frequencies showed no such difference among the 4 SNPs between patients and controls. We noted a significant difference in rs1544325 allele frequencies according to onset age. Also, in female patients, rs1544325 allele and genotype frequencies varied significantly according to onset age. CONCLUSION: This study found no genetic association between the COMT gene's 4 SNPs and schizophrenia in Koreans. However, our findings suggest genetic components for sex-specificity and onset age in Korean schizophrenics.