Effects of Notch activation and inhibition on human dermal fibroblast growth.

<p>Notch activation slows down cell growth rate of fibroblasts. Proliferation of transduced FF2441 cells was determined by MTT assays (<b>A</b>). Activated Notch1 inhibited cell growth of fibroblasts. (<b>B</b>) Inhibition of Notch activation by ectopic expression of DN-MAML-1 (<i>upper</i>) in FF2441-NICD-GFP cells relieves cell growth inhibition as measured by MTT assay (<i>lower</i>). Data are presented as mean ± SD of three independently performed experiments in (A) and (B). (<b>C</b>) Notch activation does not induce cell apoptosis in fibroblasts. Cell apoptosis was determined by TUNEL assay. No obvious apoptotic cells were detectable in FF2441-NICD1-GFP cells. Serum starvation-induced cells were used as positive control (FBS-).