Values of promoter hypermethylation of FHIT, p16, MGMT and RASSF1A genes in plasma in the diagnosis of lung cancer

Objective: To investigate the values of detection of promoter methylation status of cancer suppressor genes such as fragile histidine triad (FHIT), p16, O6-methyl-guanine-DNA methyltransferase (MGMT) and Ras association domain family 1A (RASSF1A) genes in plasma or their combined detection in the screening and early diagnosis of lung cancer. Methods: The methylation-specific PCR (MSP) method was used to detect the promoter methylation status of FHIT, p16, MGMT and RASSF1A genes in lung cancer tissues and plasma from 53 cases and lung benign tissues from 24 cases. Results: The positive rates of promoter methylation of FHIT, p16, MGMT and RASSF1A genes in lung cancer tissues were 39.6% (21/53), 49.1% (26/53), 35.8% (19/53) and 18.9% (10/53), respectively; and the positive rates in the corresponding plasma were 35.8% (19/53), 49.1% (26/53), 28.3% (15/53), and 17.0% (9/53), respectively. The positive rates of promoter methylation in the two samples were coincident (P0.05). The promoter methylation of p16 gene was seen both in plasma and lung benign tissue from one of 24 cases (0.04%). There was a significant difference between the lung cancer group and lung benign lesion group (P0.05). Combined detection of promoter methylation of FHIT, p16, MGMT and RASSF1A genes in plasma could increase the sensitivity (73.6%) and specificity Values of promoter hypermethylation of FHIT, p16, MGMT and RASSF1A genes in plasma in the diagnosis of lung cancer KANG Chun-yan1, ZHOU Hui-cong2, TANG Shao-peng3, XIAO Hong1 1. Department of Pathology, Henan Medical College for Staff and Workers, Zhengzhou 451191, China; 2. Department of Gastroenterology, First Affiliated Hospital of Xinxiang Medical College, Weihui 453100, China; 3. Thoracic Surgery, Henan Chest Hospital, Zhengzhou 450003, China Abstract Objective: To investigate the values of detection of promoter methylation status of cancer suppressor genes such as fragile histidine triad (FHIT), p16, O6-methyl-guanine-DNA methyltransferase (MGMT) and Ras association domain family 1A (RASSF1A) genes in plasma or their combined detection in the screening and early diagnosis of lung cancer. Methods: The methylation-specific PCR (MSP) method was used to detect the promoter methylation status of FHIT, p16, MGMT and RASSF1A genes in lung cancer tissues and plasma from 53 cases and lung benign tissues from 24 cases. Results: The positive rates of promoter methylation of FHIT, p16, MGMT and RASSF1A genes in lung cancer tissues were 39.6% (21/53), 49.1% (26/53), 35.8% (19/53) and 18.9% (10/53), respectively; and the positive rates in the corresponding plasma were 35.8% (19/53), 49.1% (26/53), 28.3% (15/53), and 17.0% (9/53), respectively. The positive rates of promoter methylation in the two samples were coincident (P0.05). The promoter methylation of p16 gene was seen both in plasma and lung benign tissue from one of 24 cases (0.04%). There was a significant difference between the lung cancer group and lung benign lesion group (P0.05). Combined detection of promoter methylation of FHIT, p16, MGMT and RASSF1A genes in plasma could increase the sensitivity (73.6%) and specificity (95.8%) in the diagnosis of lung cancer. The positive rate of promoter methylation of p16 in plasma was significantly correlated with smoking index (P0.05). Conclusion: Joint detection of promoter methylation of lung cancer-related genes in plasma may become a feasible and effective index in the screening and early diagnosis of lung cancer.