Effect of D-allose on prostate cancer cell lines: phospholipid profiling by nanoflow liquid chromatography-tandem mass spectrometry

d-Allose, a rare, naturally occurring monosaccharide, is known to exert anti-proliferative effects on cancer cells. The effects of d-allose on the cellular membranes of hormone-refractory prostate cancer cell line (DU145), hormone-sensitive prostate cancer cell line (LNCaP), and normal prostate epithelial cells (PrEC) were studied at the molecular level by phospholipid (PL) profiling using a shotgun lipidomic method. The molecular structures of 85 PL species including 23 phosphatidylcholines, 12 phosphatidylethanolamines (PEs), 11 phosphatidylserines (PSs), 16 phosphatidylinositols, 9 phosphatidic acids (PAs), and 14 phosphatidylglycerols (PGs) were identified by data-dependent collision-induced dissociation of nanoflow liquid chromatography–tandem mass spectrometry, and the PL amounts were quantified. The addition of d-allose to prostate cancer cell lines during their growth phases had negligible or decreased effects on the relative regulation of PL species, but several new PS molecules (two for DU145 and three for LNCaP) emerged. In contrast, experiments on the PrEC cell line revealed that some high abundant species (14:0/14:0-PE, 16:2/16:0-PG, and 20:6/18:1-PA) showed significant increases in concentration. These findings support a mechanism for the anti-proliferative effect of d-allose on prostate cancer cell lines that involves the induction of programmed cell death since PS molecules are known to induce apoptosis. Principal component analysis was carried out to examine differences in PL distributions among the three cell lines promoted by d-allose.