Lower arachidonic acid content and preferential β-oxidation of arachidonic acid over palmitic acid in tumour cell lines as compared to normal lymphoid cells.

In several studies certain polyunsaturated fatty acids (PUFA) have been shown to be selectively tumouricidal or suppressive of tumour cell proliferation. The mechanism behind this phenomenon likely involves peroxidation of the PUFA and generation of free radicals to which tumour cells seem to be more sensitive than normal cells. In this report we have measured the total lipid content in separated lymphoid cells and several tumour cell lines, among which, T-cell leukaemia, monocytic leukaemia, melanoma, fibrosarcoma, lung carcinoma and colon adenocarcinoma are included. Generally these tumour cell lines contain only one half to one third of the relative amount of arachidonic acid (AA) as compared to freshly prepared lymphocytes and monocytes or lymphocytes kept in culture. Furthermore, when we measured the beta-oxidation in long term incubation of [1-C-14] AA and compared it with that of [1-C-14] palmitic acid we found that several of the tumour cell lines showed a preference for AA over palmitic acid in the tumour cell lines whereas the opposite was observed for normal lymphoid cells.