title: [Studies on keratocystic odontogenic tumors].
abstract: Keratocystic odontogenic tumors (KCOTs, previously known as odontogenic keratocysts) are aggressive, noninflammatory jaw lesions with a putative high growth potential and a propensity for recurrence. This article puts together a summary of the serial studies related to KCOTs undertaken by the author's research group in recent years. Intraosseous jaw cysts with a solely orthokeratinized lining epithelium have been suggested to differ from the typical KCOTs. We report 20 cases of such cyst type under the term of 'orthokeratinized odontogenic cyst (OOC)'. Apart from the presence of a keratinizing epithelial lining, the OOC lacks the other histological features of KCOT, exhibits little if any tendency to recur, has no apparent association with NBCCS, may be cured by simple enucleation, and may thus constitute its own clinical entity. Mutations in PTCH1 gene are responsible for NBCCS and are related in tumors associated with this syndrome. We have so far detected 26 PTCH1 mutations (2 mutations occurred twice) in 10 out of 34 (29.4%) sporadic and 14 out of 16 (87.5%) NBCCS-associated KCOTs. The 26 mutations consisted of 10 frameshift, 2 nonsense, 3 aberrant splicing, 4 in-frame insertion/deletion/ duplication and 7 missense mutations. Two missense mutations in PTCH2 were also detected in 2 out of 15 NBCCS related KCOT patients. By contrast, no pathogenic mutation was detected in SMO. Thus, our data, together with reports from other groups, indicate that defects of PTCH1 are involved in the pathogenesis of syndromic as well as sporadic KCOTs. The pathogenic role of PTCH2 requires further investigation. A series of in vitro studies on bone resorption of KCOTs and ameloblastomas were undertaken by this group. The results indicate that odontogenic lesions could promote bone resorption in vitro and it is likely to be related to some of the cytokines secreted by the lesions.
authors.affiliation: Department of Oral Pathology, Peking University School and Hospital of Stomatology, Beijing 100081, China. litiejun22@vip.sina.com
authors.forename: Tie-jun
authors.initials: TJ
authors.lastname: Li
authors.forename: Li-sha
authors.initials: LS
authors.lastname: Sun
authors.forename: Hai-yan
authors.initials: HY
authors.lastname: Luo
authors.forename: Jun-wei
authors.initials: JW
authors.lastname: Yuan
authors.forename: Li
authors.initials: L
authors.lastname: Gao
authors.forename: Xiao-mei
authors.initials: XM
authors.lastname: Gu
authors.forename: Xue-fen
authors.initials: XF
authors.lastname: Li
authors.forename: Li-li
authors.initials: LL
authors.lastname: Xu
mesh_terms: D006801:Humans; D007573:Jaw Neoplasms / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D009807:Odontogenic Cysts / Q000235:genetics* / Q000378:metabolism / Q000601:surgery; D009808:Odontogenic Tumors / Q000235:genetics* / Q000378:metabolism; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; D000072082:Patched-2 Receptor; D011956:Receptors, Cell Surface / Q000235:genetics*; D043562:Receptors, G-Protein-Coupled / Q000235:genetics; D000072086:Smoothened Receptor
chemical_list: C000606236:PTCH1 protein, human; C000606238:PTCH2 protein, human; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; D000072082:Patched-2 Receptor; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; C491023:SMO protein, human; D000072086:Smoothened Receptor