title: Modifications in plasma membrane lipid composition and morphological features of AH-130 hepatoma cells by polyenylphosphatidylcholine in vivo treatment.
abstract: The plasma membrane lipid composition in AH-130 hepatoma cells was found to change remarkably after polyenylphosphatidylcholine (PPC) treatment. Plasma membranes from cells grown in rats treated for 7 days i.v. with 20 mg/kg/day PPC, when compared to those of control cells, did not show significantly different amounts of cholesterol or phospholipids relative to protein content, but, surprisingly, the individual phospholipid distribution inside the two membrane leaflets changed dramatically. Phosphatidylcholine (PC), the major phospholipid in the external membrane leaflet, increased ~47% (p<0.001). By contrast, phosphatidylethanolamine (PE), the most important component of the inner leaflet, decreased nearly 37% (p<0.001), while sphingomyelin (SM) also decreased ~17%, (p=0.1). Tumor cells collected from control rats at the same time interval and observed by scanning electron microscopy, exhibited a spherical shape with numerous and randomly distributed long microvilli, the same morphological and ultrastructural features displayed by the implanted cells. Conversely, tumor cells from PPC-treated rats no longer showed the roundish cell profile, and microvilli appeared shortened and enlarged, with the formation of surface blebs. Transmission electron microscopy observations confirmed the morphological and ultrastructural cell changes, mainly seen as loss of microvilli and intense cytoplasmic vacuolization. Taken together, these results indicate that the new phospholipid class distribution in the plasma membrane leaflets, modifying tumor cell viable structures, produced heavy cell damage and in many cases brought about complete cellular disintegration.
authors.affiliation: Department of Clinical and Medical Therapy, University of Rome La Sapienza, Viale del Policlinico 155, 00161 Rome, Italy. vincenzo.cinosi@libero.it
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Cinosi
authors.forename: Roberto
authors.initials: R
authors.lastname: Antonini
authors.forename: Pasqualina
authors.initials: P
authors.lastname: Crateri
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Arancia
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000378:metabolism; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D005614:Freeze Fracturing; D008214:Lymphocytes / Q000166:cytology; D008297:Male; D008563:Membrane Lipids / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning / Q000379:methods; D046529:Microscopy, Electron, Transmission / Q000379:methods; D010713:Phosphatidylcholines / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
chemical_list: D008563:Membrane Lipids; D010713:Phosphatidylcholines; D010743:Phospholipids; C005152:lipostabil