Generation of stable cell lines

MSCV (cat# 24828), MSCV EZH2 ΔSET-Hygro (cat# 49403) EZH2-Y641-F (cat# 80077), pTRIPZ M)-YFP-EZH2 (cat# 82511), MSCV-EZH2OE (cat#75125), MSCV–EZH2^EZH1SET (cat#75126) were procured from Addgene USA. Control (MSCV), EZH2 ΔSET-Hygro, and EZH2-Y641-F cell lines were generated by utilizing a retroviral-mediated transduction system followed by puromycin selection. The HEK293-T (ATCC- CRL-3216) cell line was used for the generation of viral particles following standard protocol. The HEK293-T cells were plated in the 6-well plate at 80% confluency. Polybrene (8 μg/ml) was added to the viral soup during the transduction of matured viral particles into the target cells. MSCV control cells were subjected to puromycin, and EZH2 Y641-F and EZH2 ΔSET cells were subjected to hygromycin selection, and the overexpression of stable EZH2, ΔSET, and EZH2-Y641-F was confirmed by western blot. Following the same protocol reported in our recent publication⁶⁶ EZH2 mouse, KRT14 mouse, and Human shRNA, SP1 mouse, and human and UTX mouse shRNA sequence were cloned in the 3rd generation transfer plasmid pLKO.1 TRC cloning vector (Addgene cat # 10878) between unique AgeI and EcoRI restriction sites downstream of the U6 promoter. HEK-293T cell line was used for the generation of lentiviral particles, and media containing the viral particles was supplemented with Polybrene (8 μg/ml) for the transduction purpose. Cells were subjected to puromycin selection after 48 h of transduction, and the knockdown for EZH2 and KRT14 was confirmed by western blot. shRNA sequences were listed in Supplementary Table ⁴.