| Popis: |
We have examined the secretion of IL-3 like activity from recipient normal mouse, rat and Chinese or Syrian hamster cells and their derivative cell lines obtained after transfection with recombinant plasmids carrying an exogenous human ras or myc gene. IL-3 like activity was determined by two cell proliferation assays which employed the FDC-P1 and 32D IL-3 dependent mouse cell lines. The colorimetric MTT assay, where a tetrazolium salt is employed, and the trypan blue dye exclusion assay were used. Low serum containing supernatants from rat or Syrian hamster lines expressing an exogenous human normal or mutant T24 H-ras1 gene supported the proliferation of the IL-3 dependent FDC-P1 or 32D cells. However, supernatants from mouse BalbC or Chinese hamster cells expressing the normal or mutant T24 H-ras1 gene failed to support the proliferation of these cells. In addition, supernatants from rat 208F or BalbC cells transfected with recombinant plasmids carrying a human myc gene supported the proliferation of the two IL-3 dependent cell lines. Our results suggest that introduction of the human Ha-ras1 or human myc gene can trigger the secretion of IL-3 like growth factors in some but not all rodent cells. |
