The effects of various lipoproteins on the growth and the differentiation of cultured normal human keratinocytes were invertigated. Primary cultures of human epidermal keratinocytes were obtained from neonatal foreskin, and then added with lipoproteins, very low density lipoprotein (VLDL), low density lipoprotein (LDL), and high density lipoprotein (HDL). Cell growth potential was examined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazoliurn bromide (MTT) assay. VLDL and LDL enhanced keratinocytes growth and LDL receptor expression at the plasma membrane level. These effects were more remarkably observed in cells cultured with VLDL than in cells cultured with LDL. Apolipoprotein E (ApoE) was highly increased in VLDL treated cells. These results suggest that VLDL binds with high affinity to cell surface receptors and induces cell proliferation.