Cardiolipin composition correlates with prostate cancer cell proliferation

Prostate cancer (PC) is the second most diagnosed cancer in men. It has been recognized that diet can play a crucial role in PC genesis and progression. In this context, free fatty acids are considered as modulators of cell proliferation. Recently, a relationship between the composition of the mitochondrial phospholipid cardiolipin (CL) and cell proliferation has been discussed. The aim of this study was to analyse the interrelationship between CL composition and the proliferation of prostate cells by exposing PC-3 tumour cells to different fatty acids and by analysing the CL composition in prostate tissue from PC patients after prostatectomy. Among the applied fatty acids, palmitic acid was found to stimulate proliferation of PC-3 cells, whereas oleic acid (OA) had an inhibiting effect. The lipidomic analysis of CL revealed that fatty acids supplied to PC-3 cells were incorporated into CL molecules. Further, the CL content of palmitoleic acid (C16:1) exclusively correlated with the proliferation of PC-3 cells. The CL composition significantly differed between tumour and normal prostate tissue from PC patients. In five out of six patients, the CL content of palmitoleic acid was higher in tumour prostate tissue in comparison to normal prostate tissue. Our data illustrate that the composition of CL can be easily modified by the fatty acid environment of cells. OA was most effective in decreasing the amount of palmitoleic acid within the CL molecules and deceleration of PC-3 cell proliferation. In conclusion, a diet rich in OA might be beneficial in protecting from rapid proliferation of PC cells.