Down-regulation of Gli1 expression and transcriptional activity after CK2α knockdown in mesothelioma cell lines. (A) Gli1 mRNA levels after treatment with CK2α siRNA. (B) Gli1 protein levels after treatment with CK2α siRNA. (C) The transcriptional activity of Gli1 after treatment with CK2α siRNA in H28. Silencing of CK2α resulted in a significant decrease (more than 48% at 50 μM siRNA) of the transcriptional activity. (D) Down-regulation of two target genes of the Hh pathway (Gli1 and Ptc1), detected by quantitative RT- PCR.