Fig. 4.

EZH2 interacts with and is epistatic with DDB1-DDB2 in sensitizing SCLC cells to cisplatin and UV. a HeLa cells were transiently transfected with GFP-EZH2. 72 hours post-transfection, cells were treated with 25 μM cisplatin and harvested 4 hours later, and GFP-EZH2 was immunoprecipitated (IP’d) with protein A agarose beads. Beads were washed and processed for mass spectrometry (MS) analysis for protein-protein interactions. b Summary of IP-MS results for GFP-EZH2. c and d HeLa cells were transfected with HA-DDB1 and GFP-EZH2 or empty vector and IP’d with an anti-GFP antibody (c) or anti-HA antibody (d) respectively, run on SDS-PAGE, and immunoblotted with indicated antibodies. e HeLa cells were transfected with GFP-EZH2. Cells were harvested, lysed, and IP’d with an anti-EZH2 antibody or IgG as indicated. Samples were run on SDS-PAGE and immunoblotted with indicated antibodies. f H128 cells were lysed and IP’d with an anti-EZH2 antibody or IgG as indicated. Samples were run on SDS-PAGE and immunoblotted with indicated antibodies. g, h and j H128 cells were transfected with siRNAs targeting EZH2, DDB1, DDB2, ATR, ERCC1, or a NT control. 72 hours after transfection, cells were treated with cisplatin or UV. Cell viability was measured 72 hours after treatment. i Western blot analysis of samples corresponding to g and h. k Western blot analysis of samples corresponding to j. (For g, h and j, mean and standard deviation of three replicas is shown. For c-f, representative blots from 3 independent experiments (n=3) is shown).