The zinc finger transcription factor GLI1, which mediates Sonic hedgehog signaling during development, is expressed in several human cancers, including basal cell carcinoma, medulloblastoma, and sarcomas.
Using microarrays, we demonstrated that, among genes located on 12q13-q15, SAS/CDK4 were amplified in six sarcomas, and MDM2 and GLI in five and four sarcomas, respectively.
Samples from 40 patients (37 sarcomas and 3 benign mesenchymal tumors) and samples of 15 normal mesenchymal tissues were examined for GLI gene amplification and expression by Southern hybridization, reverse transcription-PCR of tissue RNA, and immunohistochemistry, using a new polyclonal GLI antibody developed against an epitope outside of the zinc finger region.
Because of the potential importance of overproduction of this protein in neoplastic development, we examined DNAs from 29 cases of childhood sarcoma for evidence of amplification of the gli gene.