Fatemeh Khatami1, Ladan Teimoori-Toolabi2, Ramin Heshmat1, Shirzad Nasiri3, Hiva Saffar4, Mahsa Mohammadamoli5, Mohammad Haddadi Aghdam2, Bagher Larijani6, Seyed Mohammad Tavangar1,4. 1. Chronic Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran. 2. Molecular Medicine Departments, Pasteur Institute of Iran, Tehran, Iran. 3. Departments of Surgery, Tehran University of Medical Sciences, Shariati Hospital, Tehran, Iran. 4. Departments of Pathology, Dr. Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran. 5. Metabolic Disorders Research Center, Endocrinology and Metabolism Molecular -Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran. 6. Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
Abstract
Papillary thyroid cancer (PTC) is the most common type of cancer among thyroid malignancies. Tumor-related methylation of circulating tumor DNA (ctDNA) in plasma could represent tumor specific alterations can be considered as good biomarkers in circulating tumor cells. In this study, we studied the methylation status of seven promoter regions of two DNA methyl Transferases (MGMT and DNMT1) genes as the methylated ctDNA in plasma and tissue samples of patients with PTC and goiter patients as noncancerous controls. METHODS: Both ctDNA and tissue genomic DNA of 57 PTC and 45 Goiter samples were isolated. After bisulfite modification, the methylation status was studied by Methylation-Sensitive High Resolution Melting (MS-HRM) assay technique. Four promoter regions of O6-methylguanine-DNA methyltransferase (MGMT) and three promoter regions of DNA methyltransferase 1 (DNMT1) were assessed. RESULTS: From seven candidate promoter regions of two methyltrasferase coding genes, the methylation status of ctDNA within MGMT (a), MGMT (c), MGMT (d), and DNMT1 (b) were meaningfully different between PTC cases and controls. However, the most significant differences were seen in circulating ctDNA MGMT (c) which was hypermethylated in 25 (43.9 %) of patients with PTC vs 2 (4. 4 %) of goiter samples. Between two selected DNA methyl transferase, the methylation of MGMT as the maintenance methyltransferase was significantly higher in PTC cases than goiter controls (P-value < .001). The resulting areas under the receiver operating characteristic (ROC) curve were 0.78 for MGMT (d) for PTC versus goiter samples that can represent the overall ability of MGMT (d) methylation status to discriminate between PTC and goiter patients. CONCLUSION: Among seven candidate regions of ctDNA the MGMT (c) and MGMT (d) showed higher sensitivity and specificity for PTC as a suitable candidates as biomarkers of PTC.
Papillary thyroid cancer (PTC) is the most common type of cancer among thyroid malignancies. Tumor-related methylation of circulating tumor DNA (ctDNA) in plasma could represent tumor specific alterations can be considered as good biomarkers in circulating tumor cells. In this study, we studied the methylation status of seven promoter regions of two DNA methyl Transferases (MGMT and DNMT1) genes as the methylated ctDNA in plasma and tissue samples of patients with PTC and goiterpatients as noncancerous controls. METHODS: Both ctDNA and tissue genomic DNA of 57 PTC and 45 Goiter samples were isolated. After bisulfite modification, the methylation status was studied by Methylation-Sensitive High Resolution Melting (MS-HRM) assay technique. Four promoter regions of O6-methylguanine-DNA methyltransferase (MGMT) and three promoter regions of DNA methyltransferase 1 (DNMT1) were assessed. RESULTS: From seven candidate promoter regions of two methyltrasferase coding genes, the methylation status of ctDNA within MGMT (a), MGMT (c), MGMT (d), and DNMT1 (b) were meaningfully different between PTC cases and controls. However, the most significant differences were seen in circulating ctDNA MGMT (c) which was hypermethylated in 25 (43.9 %) of patients with PTC vs 2 (4. 4 %) of goiter samples. Between two selected DNA methyl transferase, the methylation of MGMT as the maintenance methyltransferase was significantly higher in PTC cases than goiter controls (P-value < .001). The resulting areas under the receiver operating characteristic (ROC) curve were 0.78 for MGMT (d) for PTC versus goiter samples that can represent the overall ability of MGMT (d) methylation status to discriminate between PTC and goiterpatients. CONCLUSION: Among seven candidate regions of ctDNA the MGMT (c) and MGMT (d) showed higher sensitivity and specificity for PTC as a suitable candidates as biomarkers of PTC.