Gene expression profiling of ameloblastoma and human tooth germ by means of a cDNA microarray

The molecular and genetic characteristics of ameloblastoma are still poorly understood. We analyzed gene expression in fresh-frozen ameloblastomas and human fetal tooth germs, using a cDNA microarray. Thirty-four genes exhibited significant changes in expression levels in the ameloblastoma. Eleven genes were overexpressed more than three-fold, and 23 genes were underexpressed to below 0.4 of the control level. The oncogene FOS was the most overexpressed gene (from eight- to 14-fold), followed by tumor-necrosis-factor-receptor 1 (TNFRSF1A). Genes for sonic hedgehog (SHH), TNF-receptor-associated-factor 3 (TRAF3), rhoGTP-ase-activating protein 4 (ARHGAP4), deleted in colorectal carcinoma (DCC), cadherins 12 and 13 (CDH12 and 13), teratocarcinoma-derived growth-factor-1 (TDGF1), and transforming growth-factor-beta1 (TGFB1) were underexpressed in all tumors. In selected genes, a comparison between cDNA microarray and real-time RT-PCR confirmed similar relative gene expression changes. The gene expression profile identifies candidate genes that may be involved in the origination of ameloblastoma and several genes previously unidentified in relation to human tooth development.