SCF-mediated c-Kit signaling in stably transfected BA/F3 cell lines. (A) c-Kit expression in stable transfected BA/F3 cell lines was measured by surface staining of stably transfected BA/F3 c-Kit and BA/F3 c-Kit787F cells. Staining with c-Kit–specific antibodies of 3 different BA/F3 c-Kit and BA/F3 c-Kit787F cell lines each (white histograms, MFI indicated) and isotype controls (gray histograms) are shown. One representative experiment from 3 is shown. (B) Untransfected BA/F3 cells or stably transfected BA/F3 c-Kit and BA/F3 c-Kit787F cells were left unstimulated or stimulated with 100 ng/mL SCF for 1 and 5 minutes. Postnuclear supernatants were immunoblotted with antibodies specific for (phospho-)Erk1/2 and actin (loading control). One representative experiment from 3 is shown. (C) SCF increases survival of stably transfected BA/F3 c-Kit, but not BA/F3 c-Kit787F cells in the absence of IL-3. Stably transfected BA/F3 c-Kit cells (3 different cell lines), BA/F3 c-Kit787F (3 different cell lines), and untransfected controls were left untreated or stimulated with SCF (100 ng/mL) or IL-3 (5 ng/mL) for 48 hours. Cell survival was measured using annexinV/PI staining. One representative experiment from 4 is shown (*P = 9 × 10−4;**P = 2 × 10−4; ***P = 8 × 10−6).
