Lipid composition of hepatitis B virus surface antigen particles and the particle-producing human hepatoma cell lines.
More than 90% of lipids of hepatitis B virus surface antigen (HBsAg) particles produced by two human hepatoma cell lines (huGK-14 and PLC/PRF/5) were composed of phospholipids, with phosphatidylcholine being the dominant component, accounting for more than 80% of total membrane lipids. Analysis of subclass compositions of phospholipids of HBsAg particles and the host cell lines revealed that 1,2-diacyl glycerophosphocholine was preferentially incorporated into the membrane of the HBsAg particles, although both host cell lines contained extremely high concentrations (more than 60% of total phospholipids) of ether-linked phospholipids. Phospholipids of other hepatoma cell lines (HuH-7, Hep-G2, and huL-1) which were not associated with hepatitis B virus (HBV) infection, were composed mostly of 1,2-diacylglycerophospholipids. Activities of dihydroxyacetone-phosphate acyltransferase, which is known to be an obligatory enzyme in ether lipid biosynthesis, were found to be elevated by three- to fourfold in both huGK-14 and PLC/PRF/5 cells compared to those of other hepatoma cell lines. The results suggest a possible relationship between HBV-induced hepatocellular carcinogenesis and the drastic change in the metabolism of membrane phospholipids.
Satoh
O
O
Mieji Institute of Health Science, Kanagawa, Japan.
Umeda
M
M
Imai
H
H
Tunoo
H
H
Inoue
K
K
D000217:Acyltransferases / Q000378:metabolism; D006528:Carcinoma, Hepatocellular; D006514:Hepatitis B Surface Antigens / Q000032:analysis*; D006515:Hepatitis B virus / Q000032:analysis* / Q000502:physiology; D006801:Humans; D008113:Liver Neoplasms; D008563:Membrane Lipids / Q000032:analysis*; D010743:Phospholipids / Q000032:analysis*; D014407:Tumor Cells, Cultured
D006514:Hepatitis B Surface Antigens; D008563:Membrane Lipids; D010743:Phospholipids; D000217:Acyltransferases; C020051:glycerone-phosphate O-acyltransferase