title: Growth stimulation by direct cell-cell contact (contact stimulation) in normal human lung fibroblasts.
abstract: Clonal growth of the normal human lung fibroblasts, IMR-90, is stimulated efficiently by utilizing feeder fibroblasts. Under the sparse culture conditions, IMR-90 cells located close to the feeder cells formed colonies with a higher efficiency than those isolated from the feeders within the same dish. The IMR-90 cells in direct contact with the 3T3 cell feeders, as monitored by metabolic cooperation, showed a faster entrance into S phase than did the IMR-90 cells isolated from the feeders. The isolated cells, even when they remained closer to the feeder cells, entered S phase later than those of the IMR-90 cells making direct contact with the feeders with long pseudopods. Medium- and dish-surface-conditioning with the feeders resulted in marginal improvement of the clonal growth. These observations suggest that contact stimulation of growth occurs in sparse cultures of normal human lung fibroblasts.
mesh_terms: D002450:Cell Communication; D002455:Cell Division; D002460:Cell Line; D002999:Clone Cells; D004247:DNA / Q000096:biosynthesis; D005347:Fibroblasts / Q000166:cytology; D005353:Fibronectins / Q000494:pharmacology; D006801:Humans; D008168:Lung / Q000166:cytology*; D013997:Time Factors
chemical_list: D005353:Fibronectins; D004247:DNA