Effect of silica on the proliferative behavior of human lung fibroblasts.

We show that silica enhances the proliferation of some but not all lung derived fibroblastlike cells (FLC) of fetal and adult origin. Cultures were obtained from lung biopsy and lavage of normal individuals and patients with interstitial lung disease. The responses of these cell lines were heterogeneous; some cultures were stimulated to proliferate in the presence of silica and others were not stimulated. There was no apparent correlation between source of the cell lines and the effects of silica. The proliferative capacity of the cells appeared to be an important determinant of the effect of silica on the growth of the cultures.