Figure 4.
DNA-damaging agent temozolomide (TMZ) enhances the effect of γ-Secretase inhibitor (GSI) RO4929097 in a Phosphatase and Tensin Homolog (PTEN)-dependent manner. A: TMZ enhances the effect of GSI, as determined by measuring cell proliferation using the Dojindo Cell Counting Kit, indicating the percentage of growth/proliferation inhibition as compared with control. B: SK-Mel 32, SK-Mel 267, SK-Mel 133 and SK-Mel 39 cells were treated with DMSO as control (ND), 5 μM GSI-alone, 300 μM TMZ, or their combination and the total protein lysates were probed with c-Notch-1, PTEN, c-PARP, pAKT and tubulin antibodies. C (i): MDA-MB-468 vector cells or PTEN-inducible cells treated with DMSO as control or 5 μM GSI-alone, 300 μM TMZ, or their combination and the total protein lysates were probed with c-Notch-1, PTEN, c-PARP, pAKT and tubulin antibodies. (ii) Fluorescence-activated cell sorting analysis (FACScan) revealed increased sub-G1 peak under the same conditions.