A FTIR microspectroscopic study of the uptake and metabolism of isotopically labelled fatty acids by metastatic prostate cancer

Recent epidemiological studies have positively associated total dietary fat intake to prostate cancer (CaP) incidence and progression. However, the role of fat-specific intake remains unclear through these patient-orientated studies, which in-turn warrants the need for controlled molecular based investigations. FTIR microspectroscopy is now a well established tool for the metabolomic analysis of a wide variety of biomolecules at the whole cell level and can be used to generate hypotheses to refine molecular specific experiments. For the first time, we have used FTIR microspectroscopy to measure the uptake and metabolism of the saturated fatty acid (FA), palmitic acid (PA) and the unsaturated FA, arachidonic acid (AA) using deuterated analogues. We also report on the temporal fluctuations of different biomolecular domains (lipid, phosphate and protein secondary structure) within PC-3 cells in response to D8-AA and D31-PA uptake. Our results demonstrate that (i) FTIR can be used to track eicosonoid generation in D8-AA stimulated cells; (ii) the intracellular management of D31-PA at high-loadings can be elucidated by monitoring lipid biosynthesis through the lipid hydrocarbon peak area signal; (iii) metabolism of lipid pools results in significant protein phosphorylation.