FIGURE 4. Src kinase synergizes with exogenous palmitic acid to regulate mitochondrial respiration in prostate cancer cells.

(A-B) PC-3 cells were transduced with shRNA-Control or shRNA-Src by lentiviral infection. 4 × 10⁴ of the transduced PC-3 cells were plated in each well of the XF24 cell culture plate. (C-D) 22Rv1 cells were transduced with control vector (Control) or Src(WT) by lentiviral infection. 6 × 10⁴ of the transduced 22Rv1 cells were plated in each well of the XF24 cell culture plate. The cells were grown with 10% FBS overnight. The medium was replaced with substrate-limited medium to prime the cells for utilization of exogenous PA and tested with XF Palmitate-BSA FAO Substrate. Oxygen consumption rate (OCR) was measured using a Seahorse Extracellular Flux (XF) Analyzer after sequential injection of oligomycin (OM, 3 μM), FCCP (5 μM), and rotenone & antimycin (R/A, 2 μM). Basal respiration and maximal respiration were calculated based on the data from Panel A or C for PC-3 cells (B) and 22Rv1 cell (D), respectively. Data are represented as mean ± SD (n=5). *: p<0.05; **: p<0.01; N.S., not significant.