Genetic changes in sporadic keratocystic odontogenic tumors (odontogenic keratocysts)

Little is known about the genetic background of keratocystic odontogenic tumors ( KCOT, odontogenic keratocysts). Our aim was to characterize genomic aberrations in sporadic KCOT using cDNA-expression arrays and array-comparative genomic hybridization. For cDNA-expression arrays, 10 KCOT specimens and 20 fetal tooth germs were studied. Quantitative realtime reverse-transcription/polymerase chain-reaction and immunohistochemical studies were also undertaken. Several genes were overexpressed in 12q13, including cytokeratin 6B (KRT6B) (approximate to 10-fold), epidermal growth factor receptor ERBB3 (similar to 4.7- fold), and glioma-associated oncogene homologue 1 (GLI1) (similar to 5- to 12-fold). One amplicon (similar to 0.7 Mega base pairs [Mbp]), covering several genes involved in the regulation of cell growth, was found in 12q13.2. Deletions were found in 3q13.1, 5p14.3, and 7q31.3, including the cell-adhesion-related gene cadherin 18 (CDH18) and leukocyte cell adhesion molecule (ALCAM, MEMD). Over-expressed and amplified genes in 12q13, also reported in several other tumors and cell lines, may contribute to the persistent growth characteristics of KCOT.