BACKGROUND AND AIM: DNA methylation plays an important role during colorectal cancer (CRC) carcinogenesis. DNA methyltransferase 1 (DNMT1) is responsible for maintaining DNA methylation. We addressed the significance of DNMT1 expression in CRC. MATERIALS AND METHODS: We measured the expression of DNMT1 in CRC tissues and in their corresponding distal normal colorectal mucosa using reverse transcriptase-polymerase chain reaction and immunohistochemical analysis. RESULTS: The mean +/- SD of DNMT1 mRNA in CRC tissues was 1.04 +/- 0.36, which was significantly higher than that in their corresponding distal normal colorectal mucosa (0.58 +/- 0.44, P < 0.05). Fifty-eight out of 77 (75.3%) CRC tissues and only 30 out of 77 (39%) corresponding distant normal colorectal mucosa showed immunoreactivity (P < 0.001). We also found that the immunoreactivity of DNMT1 was higher in mucosa adjacent to cancer than in corresponding normal colorectal mucosa; high immunoreactivity was significantly correlated with poor differentiation in CRC tissues (P = 0.008). No significant associations were found between DNMT1 immunoreactivity and the following variables: age, sex, locations of cancer, Duke's phase, and the presence of lymph-node metastasis. CONCLUSION: These findings suggested that DNMT1 was associated with the malignant phenotype, and dysregulation of DNMT1 expression was present in tumor cells of CRC.
BACKGROUND AND AIM: DNA methylation plays an important role during colorectal cancer (CRC) carcinogenesis. DNA methyltransferase 1 (DNMT1) is responsible for maintaining DNA methylation. We addressed the significance of DNMT1 expression in CRC. MATERIALS AND METHODS: We measured the expression of DNMT1 in CRC tissues and in their corresponding distal normal colorectal mucosa using reverse transcriptase-polymerase chain reaction and immunohistochemical analysis. RESULTS: The mean +/- SD of DNMT1 mRNA in CRC tissues was 1.04 +/- 0.36, which was significantly higher than that in their corresponding distal normal colorectal mucosa (0.58 +/- 0.44, P < 0.05). Fifty-eight out of 77 (75.3%) CRC tissues and only 30 out of 77 (39%) corresponding distant normal colorectal mucosa showed immunoreactivity (P < 0.001). We also found that the immunoreactivity of DNMT1 was higher in mucosa adjacent to cancer than in corresponding normal colorectal mucosa; high immunoreactivity was significantly correlated with poor differentiation in CRC tissues (P = 0.008). No significant associations were found between DNMT1 immunoreactivity and the following variables: age, sex, locations of cancer, Duke's phase, and the presence of lymph-node metastasis. CONCLUSION: These findings suggested that DNMT1 was associated with the malignant phenotype, and dysregulation of DNMT1 expression was present in tumor cells of CRC.
Authors: Maria F Paz; Susan Wei; Juan C Cigudosa; Sandra Rodriguez-Perales; Miguel A Peinado; Tim Hui-Ming Huang; Manel Esteller Journal: Hum Mol Genet Date: 2003-07-15 Impact factor: 6.150
Authors: J P Issa; P M Vertino; J Wu; S Sazawal; P Celano; B D Nelkin; S R Hamilton; S B Baylin Journal: J Natl Cancer Inst Date: 1993-08-04 Impact factor: 13.506
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Authors: J Huang; A Stewart; B Maity; J Hagen; R L Fagan; J Yang; D E Quelle; C Brenner; R A Fisher Journal: Oncogene Date: 2013-09-02 Impact factor: 9.867
Authors: Wan Faiziah Wan Abdul Rahman; Khairul Shakir Ab Rahman; Siti Norasikin Mohd Nafi; Mohd Hashairi Fauzi; Hasnan Jaafar Journal: Int J Clin Exp Pathol Date: 2015-06-01