ABSTRACT
Objective: To detect the methylation status of DLEC1 promoter in the tissue and serum of colorectal cancer (CRC) patients and to evaluate its clinical relevance. Methods: Genomic DNA was extracted from the tissues (cancer tissue and. corresponding adjacent normal tissue) and sera of 71 CRC patients; serum genomic DNA was also obtained from 20 patients with benign gastrointestinal diseases and 20 healthy donors. Promoter methylation status of DLEC1 gene was detected by methylation-specific polymerase chain reaction (MSP). Results: The incidence of aberrant methylation of DLEC1 promoter was 45.1% (32/71) in CRC tissues, which was significantly higher than that in the adjacent normal tissues (7.1%, 4/56) (P< 0.001). The hypermethylation status of DLEC1 was not correlated with the clinicopathological features and CEA/CA19-9 levels of CRC patients. Moreover, DLEC1 promoter methylation was also found in 28 of 71 (39. 4%) CRC serum samples and only 1 (2.5%) of the other 40 cancer-free serum samples (P<0.001); the methylation was in accordance with that in the tumor tissues. Conclusion: Hypermethylation of DLEC1 promoter is frequently seen in CRC patients, suggesting it might be a promising biomarker for the early diagnosis of CRC.