Overexpression of PDH complex mimics the effects of MTCH2 knockdown. (A) OCI-AML2 cells were transduced with cDNA encoding PDH-E1 (E1α) or PDH-E2 tagged with 1 of 2 different nuclear localization signals (NLS1 or NLS2) or empty vector. PDH-E1α or PDH-E2 expression was analyzed by immunoblotting of whole-cell lysates or nuclear or mitochondrial fractions. (B) Growth and viability of OCI-AML2 cells overexpressing PDH-E1 (E1α) or PDH-E2 with a nuclear localizing tag (NLS1 or NLS2) were measured with the trypan blue exclusion assay. (C) Colony formation assay of OCI-AML2 cells overexpressing PDH with a nuclear localizing tag. Mean ± SD colony counts are shown. ****P < .0001 by ANOVA. (D) Histones were isolated from OCI-AML2 cells transduced with empty vector (EV), PDH-E1 (E1α), or PDH-E2 cDNAs with NLS1 or NLS2 signals. Levels of total and acetylated H3 and H4 histones were measured by immunoblotting. (E) NSE staining of OCI-AML2 cells overexpressing PDH-E1α or PDH-E2 with NLS1 or NLS2. Quantitative analysis of NSE staining was performed with ImageJ software. **P < .01; ***P < .001; ****P < .0001 by ANOVA. (F) Proliferation curves of OCI-AML2 cells transduced with shRNAs targeting MTCH2 and cotreatment with gefitinib (20 µM) for 3 days. (G) Levels of total and acetylated H3 histones, levels of PDH-E1 (E1α) and E2 in whole-cell lysate, and nuclear extracts from OCI-AML2 after MTCH2 knockdown with or without cotreatment with gefitinib (20 µM) for 3 days. Representative immunoblots are shown.