The GLI gene is a member of the Kruppel family of zinc finger proteins

Abstract

Many studies have established that a select subset of normal cellular genes are altered in cancer by point mutations, translocations or gene amplification. However, the vast majority of genetic changes that occur in neoplastic cells have not yet been identified. In an attempt to identify some of these other genetic changes, we have recently isolated a gene, GLI, by virtue of its amplification in a human glioblastoma. Subsequently, GLI was found to be amplified in other human glioblastomas (ref. 3 and unpublished data). To understand better the role of GLI in human neoplasia, we have now cloned the GLI complementary DNA (cDNA) and determined its nucleotide sequence. Analysis of the predicted translation product reveals that it contains five repeats of a DNA binding consensus sequence (zinc finger) originally described in Xenopus Transcription Factor III A (TFIIIA). Furthermore, these zinc fingers contain sequence elements that suggest the GLI gene product is a member of the recently described Kruppel family of zinc finger proteins. Additional experiments demonstrate that GLI is an evolutionarily conserved gene that is expressed in embryonal carcinoma cells but not in most adult tissues. The link between the developmentally important Kruppel family of genes and GLI is interesting considering the similarities between developing embryonic and neoplastic tissue.