Figure 6

Growth-stimulating effects of the medium conditioned with plastic plate-reactive fibroblasts on adenoma cells. FPCK-1–1 adenoma cells were plated (5 × 10³ cells/well) in 96-well plates and incubated with or without the medium containing 50% conditioned medium (CM). After 4 days incubation, the cells were fixed and nuclei were stained with crystal violet, and optical density was measured on a microplate reader. Data are expressed as mean ± sd of quadruplicate determinations compared with the untreated controls of each cell line as 100%. Cell growth assay was performed as described in “Materials and Methods.” Columns and error bars show means and standard deviations of quadruplicate samples. A, Growth-stimulating activity of CM with plastic plate-reactive fibroblasts to FPCK-1–1 cell line. The CM was stable to heating or neuraminidase (N), but labile to trypsin (T). B, The growth-stimulating activity was detected in the fraction of the CM larger than 100 kDa. C, The growth-stimulating activity in the fraction larger than 100 kDa of the medium conditioned with various mouse fibroblasts. Only the fraction larger than 100 kDa secreted from plastic plate-reactive fibroblasts stimulated the adenoma cell growth.