BI2536 potentiated metformin-induced impair of mitochondrial function in both LNCaP and C4-2 cells. (A, C) OCR under single or both drug treatment was measurement by Seahorse XFe24 analyzer. Cells were seeded in XFe24 cell culture microplates, treated with metformin, BI2536 or both for 24 hours, and subjected to the protocol for mitochondria tolerance test in which oligomycin, FCCP and Rotenone/antimycin A were added at the time points indicated. (B, D) Calculated basal respiratory rate, spare respiratory capacity, proton leak and ATP production.