Detection of hypermethylated fibrillin-1 in the stool samples of colorectal cancer patients.

Prior studies have demonstrated that analysis of gene promoter methylation in stool samples may be a potential biomarker for noninvasive colorectal cancer detection. Aberrant methylation in gene promoter is common in various cancers, and epigenetic alterations can result in down-regulation or silence of gene expression. Recently, hypermethylation of fibrillin-1 (FBN1) was reported to be associated with colorectal cancer (CRC). In this study, we examined the methylation status of FBN1 in stool samples to test CRC. For the purpose of colorectal cancer detection, we investigated FBN1 hypermethylation in the tissue and stool samples of colorectal cancer patients using methylation-specific polymerase chain reaction. The result is that out of 75 patients with colorectal cancer, 59 (78.7 %) exhibited hypermethylated FBN1 in their tumor tissue DNA. We next detected the methylation status of FBN1 in the stool DNA of these patients. The hypermethylated FBN1 occurred in 72 % (54/75) of these patients in their stool samples and occurred in 6.7 % (2/30) of healthy people (P < 0.001). The results indicated 72.0 % sensitivity and 93.3 % specificity of the test for detecting CRC by using stool samples. So, the study reveals that hypermethylation status in the promoter of FBN1 is a high specific and sensitive biomarker for colorectal cancer, and detecting hypermethylated FBNI in stool samples is a noninvasive and useful method for screening colorectal cancer.