INFLUENCE OF FATTY-ACIDS AND BOVINE SERUM-ALBUMIN ON THE GROWTH OF HUMAN HEPATOMA AND IMMORTALIZED HUMAN KIDNEY EPITHELIAL-CELLS

The protective influence of bovine serum albumin against growth inhibi tion caused by fatty acids was studied in human hepatoma (HepG2) and i mmortalized human kidney epithelial (IHKE) cells. In general, growth i nhibition by unsaturated fatty acids (0.15 mmol/liter) increased with increasing number of double bonds. For HepG2 cells crude albumin (1 g/ 100 ml) did not greatly modify growth inhibition by arachidonic, eicos apentaenoic, and docosahexaenoic acid. With oleic, linoleic, and linol enic acids, crude and defatted albumin stimulated cell growth. In cont rast, for IHKE cells both albumins counteracted growth inhibition by u nsaturated fatty acids to approximately the same extent. When HepG2 ce lls were cultured in the presence of saturated fatty acids (0.3 mmol/l iter), C2, C6, and C8 had no or little inhibitory effect. C10 and C12 inhibited cell growth appreciably, whereas C14, and especially C16, ha d poor inhibitory effects. Crude albumin counteracted growth inhibitio n by all these fatty acids. In contrast, defatted albumin had little o r no effect (except against C10 and C12), and even increased the growt h inhibition by C14 and C16. With unsaturated fatty acids there seemed to be an inverse relationship between cell growth and the concentrati on of thiobarbituric acid reactive substances (TBARS) in media. Vitami n E abolished growth inhibition (and the increase in TBARS concentrati on) by unsaturated fatty acids. The complex interaction between fatty acids and albumins calls for great caution when interpreting data on g rowth effects.