Metastasis-associated alterations in phospholipids and fatty acids of human prostatic adenocarcinoma cell lines

Metastatic variants of human prostatic adenocarcinoma cell lines (DU-145, LNCaP, and ND-1) were studied by using soft agar colony forming efficiency, nude mice tumorigenicity, in vitro invasion assay, and type IV collagenase assay. The DU-145 and ND-1 cell line snowed higher metastatic potential than LNCaP. Lipids from DU-145, ND-1, and LNCaP cells were extracted and analyzed by thin-layer chromatography and gas-liquid chromatography. The major lipids were phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, fatty acids, and cholesterol. The sphingomyelin level was significantly higher in highly metastatic cells (DU-145 and ND-1) compared with the lower metastatic variant (LNCaP). The increase in the synthetic pathway and decrease in degradation pathway of sphingomyelin in microsomal fractions was sufficient to account for the measured increase in sphingomyelin in DU-145 cells compared with LNCaP cells. The major fatty acids of these lipids were palmitic (16:0), stearic (18:0), oelic (18:1), and arachidonic acid (20:4). The arachidonic acid level was significantly decreased in DU-145 and ND-1 compared with LNCaP cells. Electron microscopic studies showed no significant changes in the morphology of DU-145, ND-1, and LNCaP cells. The results of these investigations demonstrate for the first time that sphingomyelin and arachidonic acid contents are different in high and low metastatic variants of human prostatic adenocarcinoma cell lines.Key words: prostate cancer, metastasis, morphology, phospholipids, cytogenetic.

Combined effects of age and dietary fat on beta 1-receptors and Ca2+ channels in rat hearts

Male Wistar rats were fed a standard diet or diets supplemented with 10% butter, 10% corn oil, or 10% cod liver oil from the age of 2 mo. At 7 and 24 mo of age, the fatty acid composition of total phospholipids was determined in ventricular crude sarcolemma preparations; binding capacity and affinity (1/Kd) of [3H]dihydroalprenolol and [3H]nitrendipine binding were also determined. The arachidonic acid level was significantly higher at 24 mo than at 7 mo of age in the membrane phospholipids in rats fed no extra fat, but in rats fed fat-supplemented diets, age had no effect. Affinity of Ca2+ channels for [3H]nitrendipine decreased significantly in all dietary groups between 7 and 24 mo of age, whereas the affinity of beta 1-receptors for [3H]dihydroalprenolol increased in corn oil-fed rats. Density of beta 1-receptors decreased significantly in corn oil- and butter-fed rats and rats fed no extra fat between 7 and 24 mo of age, whereas the density of Ca2+ channels decreased significantly in corn oil-fed rats. We conclude that the antagonist binding properties of Ca2+ channels and beta 1-adrenergic receptors in rat hearts may change with age depending on the dietary fat.