Table 1.
Technical details and key findings of publications addressing DNA methylation in CTCs.
| Reference | Entity | CTC Preparation | Methylation Analysis | Key Findings | ||
|---|---|---|---|---|---|---|
| Enrichment | Detection and Isolation | Locus | Method | |||
| Chimonidou, Strati et al., 2011 [117] | BC (Human) | Density centrifugation + EpCAM-coated beads | - | CST6, BRMS1, SOX17 | MSP | Positive correlation with presence and stage of disease. |
| Chimonidou, Strati et al., 2013 [118] | BC (Human) | Density centrifugation + EpCAM-coated beads | - | SOX17 | MSP (real-time) | Strong correlation between methylation detected in CTCs and cfDNA. |
| Chimonidou, Kallergi et al., 2013 [119] | BC (Human) | Density centrifugation | Detection of CK+ cells on cytospins by ICC and scratching | BRMS1 | MSP | Weak correlation between methylation and protein expression. Discordant methylation in CTCs and patient-matched PTs. |
| Friedlander, Ngo et al., 2014 [134] | mCRPC (Human) | CAM | - | Genome wide (27000 CpG) | Methylation array | Correlation between methylation in CTCs and non-matched PTs. Hypermethylation in apoptosis, angiogenesis, and VEGF pathway genes. |
| Ogunwobi, Pussyk et al., 2013 [135] | HCC (Murine cell line) | Implantation of tumor cells in mice, and establishment of CTC lines | HGF, c-Met | HRM and Pyrosequencing | HGF and c-MET overexpression in the CTC-lines correlated with hypomethylation of their promoters. | |
Notes: BC—breast cancer; mCRPC—metastatic castration-resistant prostate cancer; HCC—hepatocellular carcinoma; CAM—cell-adhesion matrix; MSP—methylation-specific PCR; HRM—high resolution melting; cfDNA—cell-free DNA; PTs—primary tumors.