Fig. 5.

Ectopic expression of MYC sensitizes ovarian cancer cell lines to the combination of Olaparib and Palbociclib. (a) The synergistic effect of Olaparib and Palbociclib in IGROV1 and SKOV3 ovarian cancer cell lines with or without MYCT58A overexpression was measured by cell viability assay after 72 h treatment. Western blot of MYC protein levels in cells as indicated. (b) Flow cytometric analysis of Annexin V and propidium iodide (PI) stained cells (IGROV1 and SKOV3 engineered with vector or MYCT58A overexpression, respectively) to evaluate apoptosis. (c) Quantitative reverse transcription PCR analysis of BRCA1, BRCA2 and RAD51 expression in ovarian cancer cell lines with or without MYCT58A overexpression, treated with drugs as indicated for 24 h. Mean ± S.D. for three independent experiments are shown. (d) Representative images of immunofluorescent staining of γH2AX and RAD51 in ovarian cancer cell lines treated with drugs as indicated for 48 h. Scale bar, 20 μm. Cells containing more than five foci were scored as positive. Mean ± S.D. for three independent experiments are shown. Olaparib, 2 μM; Palbociclib, 1 μM. *P < 0.05; **P < 0.01; ***P < 0.001 (Student's t-test).