Genetic expression profiling of six odontogenic tumors.

Odontogenic tumors are rare neoplasms arising from the odontogenic apparatus. We aimed to identify molecular characteristics associated with odontogenic tumorigenesis and malignancy. To this end, we investigated the expression level of human genes by using, for the first time in odontogenic tumors, the technique of expression profiling. Gene expression alterations common to all six odontogenic tumors were identified by the use of cDNA microarrays containing 19,000 human cDNAs. Statistical analysis on a subset of 4974 cDNAs present in the biopsies identified 506 distinct genes associated with the tumors (p-value < 0.01). Gene ontology analysis of the cellular processes which were differentially regulated in odontogenic tumors was accomplished by the use of a subset of 1409 annotated genes. Finally, 43 cDNAs differentiated the three malignant odontogenic tumors (ameloblastic carcinoma, clear cell odontogenic tumor, granular cell odontogenic tumor) from the three benign ameloblastoma biopsies (p < 0.01). The identified genes might help us better classify borderline odontogenic tumors.