The lipid composition of tumour cells

Abstract

SUMMARY1. Adenosine 5'-phosphate is converted into ATP by the combined action of adenylate kinase (adenosine triphosphate-adenosine monophosphate phosphotransferase) and creatine kinase (adenosine triphosphate-creatine phosphotransferase) in the presence of phosphocreatine, according to the equation:AMP + 2 phosphocreatine -+ ATP + 2 creatine.The conversion is not prevented as a result of treatment of the kinases with charcoal and Dowex 1 (CF-form) to remove nucleotides.2. It has been confirmed that neither creatine kinase nor adenylate kinase catalyses the direct phosphorylation of AMP by phosphocreatine.3. It appears that reaction occurs because crystalline creatine kinase contains a sufficient amount of ATP, even after treatment with charcoal and Dowex 1, to prime an autocatalytic system consisting of these reactions:AMP + ATP -+2 ADP and ADP + phosphocreatine -+ ATP + creatine (catalysed by adenylate kinase and creatine kinase respectively).

Fluctuation of Lipid Content in Ehrlich Carcinoma Cells during the Growth Period

“…Then Quagliariello et al (1968) found that fatty acid synthesis took place mainly in mitochondrial fraction through the system of chain elongation and that this enzyme system was located at the inner membrane of mitochondria. Bhaduri et al (1964) In parallel with some reports indicating high contents of C 18:0 in ascites tumor cells (Yamakawa et al 1962c, Gray 1963, our report revealed that the content of C 18:0 in simple lipids in Ehrlich ascites carcinoma cells exceeded that in normal mouse liver. Yamakawa et al (1962a), on the basis of the analysis of fatty acid compost-tion of NEFA in ascites carcinoma cells, reported that C 18:0 constituted 77% , C 16:0 16%, C 18:1 4%, and C 18:3 2% of total fatty acid , respectively.…”

Ether lipids

“…Although we have only discussed the alkyl composition in DAGE, studies have shown that the 1-O-alkyl composition in DAGE and in ether phospholipids is usually similar, but some differences are noticed in the percentages of the most abundant alkylglycerols (Gray, 1963;Hallgren et al, 1974a,b).…”

“…In the same study the levels of ethanolamine plasmalogen in human leukemia cells (42-55%) were also reduced, compared to normal leukocytes (66%) but to a lesser extent. Gray (1963) analysed the total lipid composition of two tumour cells, Landschutz ascites-carcinoma cells and BP8/C3H ascites-sarcoma cells, with especial reference to the fatty acids and phospholipids. He found that the phospholipid composition, including the plasmalogens of the tumour cells, did not show marked differences from the composition of non-tumour cells.…”

Lipid composition of SV40‐induced transplantable hamster tumor

“…Interest in the chemistry and metabolism of tumor lipids see Wood for a review (1) -is based on the desire to find correlations between changes in lipid components and biological properties of malignant cells. Among several changes found in tumor lipids by different laboratories, the more consistent ones are: a lowered amount of phospholipids (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13), the occurrence of appreciable amounts of etherlinked lipids (5,6,10,12,t3), and an increase of monoenoic acids associated with a decrease of C2o and C22 polyunsaturated fatty acids (2,6,8,(14)(15)(16)(17)(18)(19)(20)(21)(22). It is still uncertain, however, whether these changes represent general trends characteristic of cancer cells or whether they reflect cell-specific differences.…”