PTCH gene altered in dentigerous cysts

Abstract

Motivated by the evidence that odontogenic keratocysts are associated with genetic alterations, we examined the possibility that development of other odontogenic cysts can be attributed to gene malfunctioning, in particular to the PTCH gene. Cyst epithelium was examined for polymorphism on chromosome 9q22.3, the region that contains the PTCH gene. Loss of heterozygosity (LOH) for the D9S287 marker and/or D9S180 marker was observed in about 50% of dentigerous cysts, whereas radicular cysts gave no indication of lesions in the PTCH region. As a more direct argument for PTCH involvement in cystic growth, we report evidence of PTCH expression in dentigerous cyst lining, which indicates malfunctioning of the relevant signaling pathway. While we found no reason to believe that PTCH should be associated with radicular cysts, other genes may be implicated in their development. We performed immunohistochemical comparisons of keratocysts, dentigerous and radicular cysts for the nonmetastatic marker Nm23. A graded response placed radicular cysts in between the other two types, suggesting a similar neoplastic character for their epithelial proliferation.

Evidence of loss of heterozygosity of the PTCH gene in orthokeratinized odontogenic cyst

“…Surprisingly, some OOC cases presented the same alteration. LOH of the PTCH gene was previously reported in dentigerous cyst (24, 27), and recently, mutations of PTCH gene were also reported in calcifying epithelial odontogenic tumor (28). Additionally, a previous study identifies similar expression of the SHH pathway proteins SHH, PTCH, SMO, and GLI in KOTs, OOCs, dentigerous cysts, radicular cysts, and ameloblastoma (12).…”

One germline mutation of PTCH gene in a Chinese family with non-syndromic keratocystic odontogenic tumours

“…Some research has shown that DC can also be caused by the functional loss of PTCH. Some researchers thought DC might be a symptom of NBCCS 10,12 . In this family, all the patients carried the same mutation of PTCH.…”

c-Myc oncogene expression in selected odontogenic cysts and tumors: An immunohistochemical study

“…[1] Genetic mutations have also been proposed as a possible cause in the development of odontogenic cysts like odontogenic keratocyst (OKC)[2] and dentigerous cyst. [3] Studies investigating the cell kinetics of epithelial linings of odontogenic cysts indicate that the lining of OKC may have some intrinsic growth potential which is not present in other cysts[45] and thus OKC is now regarded as a benign cystic neoplasm rather than a cyst. [67]…”