Sc 55584

Antibodies: ATRX: Millipore Sigma 39F MABE1798 and Santa Cruz sc-55584 were used 1:1000 overnight in 1X TBST after 5% milk block for western blot, pChk1: CST 2341 was used at 1:500 overnight at 5% BSA in 1X TBST. Olaparib, AZD6738 and other drug screen compounds were purchased through Selleckchem.

A subset of tumors (n = 47) was analyzed for ATRX nuclear staining. Antigen retrieval was performed in a steamer using citrate buffer (H-3300; Vector Laboratories) for 30 min. Endogenous peroxidase was blocked (PV9001; ZSGB-BIO, Beijing, China), and serial sections were then incubated with primary antibody against ATRX (1:100 dilution; sc-55584; Santa Cruz, Dallas, TX, United States) overnight at 4°C. To detect primary antibody, slides were incubated with secondary antibody (PV9001, ZSGB-BIO) for 30 min, counterstained with Harris hematoxylin, rehydrated, and mounted. Staining of the GM slides was assessed and scored; epithelial cells and stromal cells were used as internal controls to display nuclear staining for ATRX (Supplementary Figure S2). ATRX expression in all samples is listed in Supplementary Table S5.