TWIST1 and melanoma: QRT-PCR experiments showed that naïve 501mel melanoma cells exposed to the secretome of melanoma cells rendered senescent by MITF silencing exhibited an increased level of SNAIL1, TWIST1, Fibronectin1, N-Cadherin (CDH2) mRNAs whereas MITF and E-Cadherin (CDH1) transcripts were markedly decreased (Fig. 1A).