Changing the lipid composition in hepatoma cell membranes can affect cell death and proliferation

Hepatoma cells have a below-normal content of polyunsaturated fatty acids; this reduces lipid peroxidation and production of cytotoxic and cytostatic aldehydes within the cells. If the arachidonic acid content is brought to values close to those of hepatocytes, hepatoma cell lines (7777 and JM2) become able to respond to prooxidants and to produce aldehydes. When hepatoma cells are enriched with arachidonic acid and stimulated to peroxidize by ascorbate/iron sulphate, their growth rate is reduced in proportion to the quantity of aldehydes produced, or they die; the effect was investigated by determining cell numbers and distribution of DNA content, or by determining LDH release, respectively. 7777 and JM2 cells have different susceptibility to lipid peroxidation, which is probably due to different patterns of lipid peroxidation aldehyde metabolizing enzymes; in particular, in JM2 cells aldehyde dehydrogenase and aldehyde reductase are above normal values.