Abstract
Fatty acid biosynthesis in Ehrlich cells in vitro was reduced when very low density lipoproteins (VLDL) isolated from the ascites tumor plasma were added to the incubation medium. The degree of inhibition was dependent on the VLDL concentration. At the VLDL concentrations usually present in the ascites plasma, there was a 30% decrease in biosynthesis as measured by3H2O incorporation into fatty acids. Analysis of the labeled fatty acids by gas liquid chromatography indicated that this decrease was due to a reduction in fatty acid de novo biosynthesis and that chain elongation actually was increased when VLDL were present. Although ascites plasma low- and high density lipoproteins also produced a concentration-dependent inhibition of fatty acid biosynthesis, their effects were much smaller than those of the VLDL. Studies employing VLDL and radioactive free fatty acids indicated that the cells took up and utilized fatty acids derived from these lipoproteins. When VLDL were present, labeled free fatty acid incorporation into cell phospholipids, cholesteryl esters, and CO2 decreased, whereas its incorporation into the cell free fatty acid pool increased. By contrast, the cells incorporated only very small amounts of fatty acid from either low- or high density lipoproteins. This suggests that the VLDL exert their inhibitory effect on fatty acid synthesis by supplying exogenous fatty acids to the cells.
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References
Goodridge, A.G., J. Biol. Chem. 248:4318 (1973).
Jacobs, R.A., and P.W. Majerus, Ibid. 248:8392 (1973).
McGee, R., and A.A. Spector, Ibid. 250:5419 (1975).
Spector, A.A., Cancer Res. 27:1580 (1967).
Mermier, P., and N. Baker, J. Lipid Res. 15:339 (1974).
McGee, R., and A.A. Spector, Cancer Res. 34:3355 (1974).
Mathur, S.N., and A.A. Spector, Biochim. Biophys. Acta 424:45 (1976).
Brenneman, D.E., S.N. Mathur, and A.A. Spector, Europ. J. Cancer 11:225 (1975).
Brennemann, D.E., and A.A. Spector, J. Lipid Res. 15:309 (1974).
Kessler, G., and H. Lederer, in “Automation in Analytical Chemistry. Technicon Symposium,” Edited by L.T. Skeggs, Jr., Mediad, Inc., New York, NY, 1966, p. 341.
Block, W.D., K.J. Jarrett, and J.B. Levine, Ibid.“, p. 345.
Folch, J., M. Lees, and G.H.S. Sloane-Stanley, J. Biol. Chem. 226:497 (1957).
Garland, P.B., and P.J. Randle, Nature 199:381 (1963).
Kuhl, W.E., and A.A. Spector, J. Lipid Res. 11:458 (1970).
Spector, A.A., D. Steinberg, and A. Tanaka, J. Biol. Chem. 240:1032 (1965).
Chen, R.F., Ibid. 242:163 (1967).
Trout, D.L., E.H. Estes, Jr., and S.J. Friedberg, J. Lipid Res. 1:199 (1960).
Lowry, O.H., W.J. Rosenbrough, W.J. Farr, and R.J. Randall, J. Biol. Chem. 193:265 (1951).
Lee, L.P.K., and I.B. Fritz, Can. J. Biochem. 50:120 (1972).
Allred, J.B., and D.G. Guy, Anal. Biochem. 29:293 (1969).
Moellering, H., and W. Gruber, Ibid. 17:369 (1966).
Spector, A.A., and D. Steinberg, J. Lipid Res. 7:657 (1966).
Brenneman, D.E., R. McGee, and A.A. Spector, Cancer Res. 34:2605 (1974).
Brown, M.S., and J.L. Goldstein, Science 191:150 (1976).
Bailey, J.M., B.V. Howard, L.M. Dunbar, and S.F. Tillman, Lipids 7:125 (1972).
Rothblat, G.H., J. Cell Physiol. 74:163 (1969).
Watson, J.A., Lipids 7:146 (1972).
Volpe, J.J., and P.R. Vagelos, Ann. Rev. Biochem. 42:21 (1973).
Wood, R., and F. Snyder, Arch. Biochem. Biophys. 131:478 (1969).
Senior, J.R., and K.J. Isselbacher, J. Biol. Chem. 237:1454 (1962).
Brown, J.L., and J.M. Johnston, Biochim. Biophys. Acta 84:448 (1964).
Kern, F., Jr., and B. Borgström, Ibid. 98:520 (1965).
Lands, W.E.M., J. Biol. Chem. 235:2233 (1960).
Stein, O., and Y. Stein, Biochim. Biophys. Acta 137:232 (1967).
Rothblat, G.H., L. Arbogast, D. Kritchevsky, and M. Naftulin, Lipids 11:97 (1976).
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McGee, R., Brenneman, D.E. & Spector, A.A. Regulation of fatty acid biosynthesis in Ehrlich cells by ascites tumor plasma lipoproteins. Lipids 12, 66–74 (1977). https://doi.org/10.1007/BF02532975
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DOI: https://doi.org/10.1007/BF02532975