Quantitative methylation-specific PCR (qMSP) analysis

The qMSP analysis was performed following a previous protocol ⁴⁰. Briefly, the DNA methylation inhibitor AZA (5-Aza-2'-deoxycytidine)-treated cells were subjected to DNA isolation using a PureLink^TM Genomic DNA Mini Kit (Thermo Fisher Scientific, #K182001) according to the manufacturer's protocol. After quantification with a Nanodrop spectrophotometer, 1 µg of genomic DNA from each sample was treated with sodium bisulfite using the EZ DNA Methylation-GOLD Kit (Zymo Research, Tustin, CA, USA, #D5006) following a protocol provided by the manufacturer. The resulting genomic DNA was used for qMSP analysis using the TaqMan^® Universal Master Mix II non-UNG Kit (Thermo Fisher Scientific, #4440038) with primers listed in Supplementary Table-4.