EFFECT OF DIET SUPPLEMENTATION WITH GAMMA -LINOLENIC ACID ON THE GROWTH OF A HUMAN LUNG-CARCINOMA IMPLANTED IN NUDE-MICE

We have studied the effect of a gammalinolenic acid (18:3 0-6, GLA)-su pplemented diet on the growth of a human lung mucoepidermoid carcinoma (HLMC) implanted in athymic mice and on its uptake of human low densi ty lipoproteins labeled with 99mTc (99mTc-LDL). Mice bearing the HLMC were divided into two experimental groups. One of them was administere d a control diet (C diet) and the other one was given a diet supplemen ted with 25 mg GLA/g pellet (GLA diet) for three weeks (Table 1). A tu mor growth inhibition with the GLA diet was evident at the second week of treatment, and a marked inhibition (56%) was reached at the end of the third week (Fig. 1). The GLA diet produced some changes in the to tal fatty acid composition of tumor, plasma and liver of host mice: GL A and arachidonic acid (20:4 n-6, AA) induced significant increases, w hereas oleic (18:1 n-9, OA) and linoleic acids (18:2 n-6, LA) were dec reased (Table 2). Tumors of those animals fed both diets were labeled by 99mTc-LDL, and no difference was observed in the ratio of tumor/liv er and tumor/kidney uptake of host animal (Table 3). Results obtained using this experimental model suggest that the inhibitory effect of GL A on tumor growth is not related to the LDL tumor uptake.