Epigenomic analysis reveals a unique DNA methylation program of metastasis-competent circulating tumor cells in colorectal cancer

Metastasis is the main cause of cancer-related deaths in patients with solid tumors, including colorectal cancer (CRC). Circulating tumor cells (CTCs) and epigenetic alterations are involved in the development of metastasis. It is important to characterize the DNA methylation pattern of metastasis-competent CTCs to better understand the metastatic process and obtain new clinical applications for cancer patients. Therefore, the aim of this study was to investigate the DNA methylation landscape of metastasis-competent CTCs in CRC. The DNA methylome of the human colorectal cancer-derived cell line CTC-MCC-41 was compared with primary (HT29, Caco2, HCT116, RKO) and metastatic (SW620 and COLO205) CRC cells using a genome-wide methylation analysis. The DNA methylome of the human colorectal cancer-derived cell line CTC-MCC-41 was compared with primary (HT29, Caco2, HCT116, RKO) and metastatic (SW620 and COLO205) CRC cells using a genome-wide methylation analysis. The association between the methylation and the transcriptional profile of CTC-MCC-41 was also evaluated. Differentially methylated CpGs were validated with pyrosequencing and qMSP.