Effect of basic fibroblast growth factor (bFGF) and insulin-like growth factors type I (IGF-I) and type II (IGF-II) on adult human keratinocyte growth and fibronectin secretion.

Effects of growth factors on keratinocyte migration and proliferation are of interest as an indication of their potential use in acceleration of wound re-epithelialization. Various growth factors were examined for effects on normal adult human keratinocyte growth and fibronectin (Fn) secretion for cells cultured in serum-free medium. Accumulation of Fn in the medium of cells growth with H + I + EGF + BPE paralleled growth during the exponential phase and declined as the cells approached confluence. Cells maintained in low Ca++ (0.15 mM) post-confluence and fed daily to prevent cornification continued to accumulate Fn in the medium, while those grown continuously in 1.2 mM Ca++ ceased Fn secretion at confluence. EGF, bFGF, and transforming growth factor-beta (TGF beta) stimulated keratinocyte Fn secretion in correlation with literature reports on the ability of these factors to stimulate the migration of these cells. In contrast, despite its marked effects on cell growth, BPE was found to consistently reduce the amount of Fn found in the medium when added to cultures containing either EGF or bFGF. Addition of BPE to cultures containing EGF or bFGF stimulated growth to the same extent, indicating that the effects of BPE on keratinocyte growth are not solely due to its content of bFGF.