Cell, Vol.
12, 295300,
September
1977,
Copyright
0 1977 by MIT
Decrease in Adhesion of Cells Cultured Polyunsaturated Fatty Acids Richard L. Hoover, Robert D. Lynch* and Morris J. Karnovsky Department of Pathology Harvard Medical School 25 Shattuck Street Boston, Massachusetts 02115 and * Department of Biological Sciences University of Lowell Lowell, Massachusetts 01854
Summary The addition of long chain unsaturated fatty acids (linoleic, linolenic and arachidonic acids) to BHK cells reduces the cell to substrate adhesion, causes morphological changes and alters the cellular growth properties. The new characteristics are similar to those of transformed cells. The data indicate that the effects are probably due to actual changes in the surface membrane lipids and not due to prostaglandin synthesis. Introduction In terms of the fluid mosaic model, lipids have a very important role in the structure and function of membranes. Not only do they affect the stability and permeability of the membrane, but they also affect the distribution of proteins, which in turn can influence other cellular functions. Studies have shown that changes in lipid compositions can modify enzyme activity (Engelhard et al., 1976), morphology (Ginsburg et al., 1973; Hawley and Gordon, 1976), concanavalin A agglutination (Horwitz, Hatten and Burger, 1974), differentiation (Weeks, 1976) and cell adhesion (Curtis, Chandler and Picton, 1975; R. L. Hoover, manuscript in preparation). The mechanism by which the lipids affect these cellular functions is still unclear. Two possible mechanisms are either that there is a direct change in the lipid composition of the cell surface which alters the fluidity of the membrane, or that the lipids are acting intracellularly through synthesis of prostaglandins which then alter membrane properties. In this paper, we demonstrate that when exogenous fatty acids are incorporated into tissue culture cells, functions involving the cell surface are affected and that the alterations in functions depend on the incorporation of a particular fatty acid. We also suggest procedures to help distinguish the mechanism through which the fatty acids act. Results The effects
of fatty acids
on the adhesion
of BHK
in
cells are summarized in Table 1. Since the percentage of control cells adhering ranges between 4070%, all data have been standardized based on a value of 1.00 for the control condition. Numbers >l .OO indicate that more cells are adhering to the substrate than in the control condition, and numbers
12, 295300,
September
1977,
Copyright
0 1977 by MIT
Decrease in Adhesion of Cells Cultured Polyunsaturated Fatty Acids Richard L. Hoover, Robert D. Lynch* and Morris J. Karnovsky Department of Pathology Harvard Medical School 25 Shattuck Street Boston, Massachusetts 02115 and * Department of Biological Sciences University of Lowell Lowell, Massachusetts 01854
Summary The addition of long chain unsaturated fatty acids (linoleic, linolenic and arachidonic acids) to BHK cells reduces the cell to substrate adhesion, causes morphological changes and alters the cellular growth properties. The new characteristics are similar to those of transformed cells. The data indicate that the effects are probably due to actual changes in the surface membrane lipids and not due to prostaglandin synthesis. Introduction In terms of the fluid mosaic model, lipids have a very important role in the structure and function of membranes. Not only do they affect the stability and permeability of the membrane, but they also affect the distribution of proteins, which in turn can influence other cellular functions. Studies have shown that changes in lipid compositions can modify enzyme activity (Engelhard et al., 1976), morphology (Ginsburg et al., 1973; Hawley and Gordon, 1976), concanavalin A agglutination (Horwitz, Hatten and Burger, 1974), differentiation (Weeks, 1976) and cell adhesion (Curtis, Chandler and Picton, 1975; R. L. Hoover, manuscript in preparation). The mechanism by which the lipids affect these cellular functions is still unclear. Two possible mechanisms are either that there is a direct change in the lipid composition of the cell surface which alters the fluidity of the membrane, or that the lipids are acting intracellularly through synthesis of prostaglandins which then alter membrane properties. In this paper, we demonstrate that when exogenous fatty acids are incorporated into tissue culture cells, functions involving the cell surface are affected and that the alterations in functions depend on the incorporation of a particular fatty acid. We also suggest procedures to help distinguish the mechanism through which the fatty acids act. Results The effects
of fatty acids
on the adhesion
of BHK
in
cells are summarized in Table 1. Since the percentage of control cells adhering ranges between 4070%, all data have been standardized based on a value of 1.00 for the control condition. Numbers >l .OO indicate that more cells are adhering to the substrate than in the control condition, and numbers
