Activation of c-kit receptor for SCF specifically induces Slug expression.

LAMA 84 cells (A) and Ba/F3 cells engineered to express c-kit (C) were stained with a monoclonal antibody recognizing c-kit and analyzed by flow cytometry (c-kit⁻ cells in panel A were unstained LAMA 84 cells). Expression of Slug and Snail was analyzed by RT-PCR in LAMA 84 cells (B) and in Ba/F3 cells engineered to express c-kit (D) in the absence and in the presence of SCF for 60 minutes at 37°C (100 ng/mL). PCR products were transferred to a nylon membrane and were analyzed by hybridization with end-labeled internal oligonucleotide probes specific for each gene. β-Actin was used to check cDNA integrity and loading. (E) Ba/F3 cells that express c-kit were incubated for the indicated periods of time with SCF (100 ng/mL) at 37°C. After incubation, Slug and actin expression were determined by Northern blot analysis. (F, G) Expression of Slug RNA is observed in primary c-kit⁺ cells purified from BM of wild-type mice, hybridized with an antisense RNA probe for Slug and subjected to DAPI (F). No Slug RNA expression is observed when a sense RNA probe is used. (G) Expression of Slug in primary c-kit⁺ cells in the absence and in the presence of SCF for 60 minutes at 37°C (100 ng/mL) analyzed by RT-PCR.