Effect of nonspecific phospholipid transfer protein on cholesterol esterification in microsomes from Morris hepatomas

Journal Article · Thu Sep 01 04:00:00 EDT 1983 · Cancer Res.; (United States)

OSTI ID:5745464

van Heusden, G P; van der Krift, T P; Hostetler, K Y; Wirtz, K W

The content of cholesterol and cholesterol ester as well as the levels of acyl coenzyme A:cholesterol acyltransferase activity were determined in the microsomes from Morris hepatomas 7777, 5123D, and 7787. The free cholesterol content, expressed per mg microsomal protein, was significantly increased only in the microsomes from Morris hepatoma 7777 (47.8 +/- 0.4 micrograms (S.D.); p less than 0.001) and hepatoma 7787 (37.6 +/- 6.2 micrograms; p less than 0.01) as compared to normal liver (28.8 +/- 2.4 micrograms). The cholesterol ester content in the microsomes of the three different tumors did not significantly differ from that of normal liver (2.1 +/- 1.2 micrograms cholesterol per mg microsomal protein). The microsomal acyl coenzyme A:cholesterol acyltransferase activity was decreased in Morris hepatoma 7777 (8.6 +/- 2.3 pmol/min/mg protein; p less than 0.01) and in hepatoma 5123D (7.5 +/- 1.7 pmol/min/mg protein; p less than 0.02), and was normal in the hepatoma 7787 (16.5 +/- 7.8 pmol/min/mg protein) as compared to rat liver (16.0 +/- 2.9 pmol/min/mg protein). In a previous study this acyltransferase activity was shown to be stimulated by preincubation of rat liver microsomes with cholesterol-containing vesicles and the nonspecific phospholipid transfer protein. In this paper, a similar 4-fold stimulation of activity was observed for the microsomes of the various hepatomas investigated. The possible role of the nonspecific phospholipid transfer protein in intracellular cholesterol esterification is discussed.

• Research Organization: Laboratory of Biochemistry, State University of Utrecht, The Netherlands
• OSTI ID: 5745464
• Journal Information: Cancer Res.; (United States), Journal Name: Cancer Res.; (United States) Vol. 43:9; ISSN CNREA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
BODY
CARBON 14 COMPOUNDS
CELL CONSTITUENTS
CHOLESTEROL
COENZYMES
DIGESTIVE SYSTEM
DISEASES
ENZYME ACTIVITY
ENZYMES
ESTERS
GLANDS
HEPATOMAS
HYDROXY COMPOUNDS
LABELLED COMPOUNDS
LIPIDS
LIVER
MALES
MAMMALS
MICROSOMES
NEOPLASMS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANOIDS
ORGANS
PHOSPHOLIPIDS
RATS
RODENTS
STEROIDS
STEROLS
TRANSFERASES
VERTEBRATES