Expression of regulatory and executor proteins of apoptosis in odontogenic keratocyst: a systematic review

The odontogenic keratocyst (OKC) corresponds to the third most common odontogenic cyst of the maxillary bones, originating from the dental lamina or its remnants. Apoptosis dysregulation, due to an imbalance between anti-apoptotic and proapoptotic proteins, has been proposed as a promoter for the development and progression of OKC. This study aimed to conduct a systematic review to synthesize the current knowledge on effector proteins of the intrinsic and extrinsic pathways, and executor proteins of apoptosis in OKC and compare their expression to other odontogenic cysts and tumors.

Primary studies were searched in PubMed, Scopus, and Web of Science databases, following the recommendations of PRISMA. Inclusion criteria were articles in English reporting the expression of at least two apoptosis-related proteins in OKC, studies using human tissues, descriptive retrospective case series, or in vitro assays.

Seven articles met the inclusion criteria and were considered for data extraction and analysis. Of the selected articles, six studied proteins related to the regulation of the intrinsic pathway of apoptosis, all reporting the immunohistochemical expression of Bcl-2 and BAX. Only one study reported the immunohistochemical expression of proteins related to the regulation of the extrinsic pathway, specifically Fas and FasL. Regarding apoptosis execution proteins, only one article characterized the immunohistochemical expression of caspases, specifically caspase-3.

OKC expresses proteins related to apoptosis regulation similar to other aggressive odontogenic lesions, such as ameloblastoma. This suggests that apoptosis dysregulation may be essential in its development and progression.