Decoding a gene expression program that accompanies the phenotype of sporadic and Basal Cell Nevus Syndrome-associated odontogenic keratocyst

BACKGROUND

Odontogenic keratocyst (OKC) is characterized by local aggressive behavior and a high recurrence rate, as well as the potential to develop in association with the Basal Cell Nevus Syndrome (BCNS). The aim of this study was to decode the gene expression program accompanying OKC phenotype.

METHODS

150-bp paired-end RNA-sequencing was applied on 6 sporadic and 6 BSCN-associated whole-tissue OKC samples in comparison to 6 dental follicles, coupled to bioinformatics and complemented by immunohistochemistry.

RESULTS

2,654 and 2,427 differentially expressed genes were captured to characterize the transcriptome of sporadic and BCNS-associated OKCs, respectively. Gene ontologies (GOs) related to "epidermis/skin development" and "keratinocyte/epidermal cell differentiation" were enriched among the upregulated genes (KRT10, NCCRP1, TP63, GRHL3, SOX21), while "extracellular matrix (ECM) organization" (ITGA5, LOXL2) and "odontogenesis" (MSX1, LHX8) GOs were overrepresented among the downregulated genes in OKC. Interestingly, upregulation of various embryonic stem cells (ESCs) markers (EPHA1, SCNN1A) and genes committed in cellular reprogramming (SOX2, KLF4, OVOL1, IRF6, TACSTD2, CDH1) was found in OKC. These findings were highly shared between sporadic and BCNS-associated OKCs. Immunohistochemistry verified SOX2, KLF4, OVOL1, IRF6, TACSTD2/TROP2, CDH1/E-cadherin, and p63 expression predominantly in the OKC suprabasal epithelial layers.

CONCLUSION

The OKC transcriptomic profile is characterized by a prominent epidermal and dental epithelial fate, a repressed dental mesenchyme fate combined with deregulated ECM organization, and enhanced stemness gene signatures. Thus, we propose a developed epidermis-like phenotype in the OKC suprabasal epithelial cells, established in parallel to a significant upregulation of marker genes related to ESCs and cellular reprogramming. This article is protected by copyright. All rights reserved.

Basaloid follicular hamartomas in pediatric Basal Cell Nevus Syndrome: A diagnostic challenge

Basal Cell Nevus Syndrome (BCNS) is an autosomal dominant inherited disease caused by PTCH1 (9q22.3‐q31) germline mutations. Skin manifestations are mainly characterized by hyperkeratosis of the palms and soles, palmoplantar pits and a strong predisposition to develop multiple basal cell carcinomas (BCCs). Recently, it has been hypothesized that basaloid follicular hamartomas (BFH) could be included in BCNS skin features. We present three pediatric cases of GS with BCCs and BFHs. Clinical, dermoscopic and immunohistochemical tools are reported.

[Gorlin-Goltz Syndrome: Diagnosis and Treatment Options]

The Gorlin-Goltz syndrome is a rare autosomal dominant hereditary condition, with complete penetrance and variable expressivity. Characterized by the appearance of multiple basaliomas, and often the development of keratocyst, it can also express itself by the presence of palmar/plantar depressions, calcification of brain sickle, and skeletal birth defects, although less frequently. This article presents two cases involving direct relatives, referred after the identification of several basaliomas and jaw cysts. After establishing the diagnosis, given the identification of three major criteria, the treatment consisted in the excision of the lesions followed, in one case, with vismodegib treatment resulting in complete remission. Gorlin-Goltz syndrome is therefore a multidisciplinary challenge, whose variable morbidity and high risk of recurrence make treatment and surveillance critical. However, new molecular targeted therapies have brought a new hope in treating these patients.

Basal cell nevus syndrome or Gorlin syndrome

Basal cell nevus syndrome (BCNS) or Gorlin syndrome is a rare neurocutaneous syndrome sometimes known as the fifth phacomatosis, inherited in autosomal dominant fashion with complete penetrance and variable expressivity. Gorlin syndrome is characterized by development of multiple basal cell carcinomas (BCCs), jaw cysts, palmar or plantar pits, calcification of falx cerebri, various developmental skeletal abnormalities such as bifid rib, hemi- or bifid vertebra and predisposition to the development of various tumors. BCNS is caused by a mutation in the PTCH1 gene localized to 9q22.3. Its estimated prevalence varies between 1/55600 and 1/256000 with an equal male to female ratio. The medulloblastoma variant seen in Gorlin syndrome patients is of the desmoplastic type, characteristically presenting during the first 3 years of life. Therefore, children with desmoplastic medulloblastoma should be carefully screened for other features of BCNS. Radiation therapy for desmoplastic medulloblastoma should be avoided in BCNS patients as it may induce development of invasive BCCs and other tumors in the skin area exposed to radiation. This syndrome is a multisystem disorder so involvement of multiple specialists with a multimodal approach to detect and treat various manifestations at early stages will reduce the long-term sequelae and severity of the condition. Life expectancy is not significantly altered but morbidity from complications and cosmetic scarring can be substantial.

Unusual cortical bone features in a patient with gorlin-goltz syndrome: a case report

Gorlin-Goltz syndrome (GGS) consists of ectodermal and mesodermal abnormalities. In this case report we will investigate lower extremity lesions of GGS. A 52-year-old man with GGS underwent skull and lower extremity computer tomography. Radiographic findings included cervical spondylosis, transparent areas with slurred margins, and cerebral falx calcification. Tibial and fibular specific cortical lesions (thin cortical and subcortical cystic lesions) were seen on the radiography, which was confirmed by computer tomography. To our knowledge, this is the first report of such a long lesion of the tibia and fibula. Specific lower extremity cortical lesions (thin cortical and subcortical cystic lesions) may occur and these abnormalities can be found on radiography or CT, which are most probably attributed to retinoid treatment.

Radiological features of familial Gorlin-Goltz syndrome

Gorlin-Goltz syndrome is an autosomal dominant disorder principally characterized by cutaneous basal cell carcinomas, multiple keratocystic odontogenic tumors, and skeletal anomalies. This syndrome may be diagnosed early by dentist because keratocystic odontogenic tumors are usually one of the first manifestations of the syndrome. Early diagnosis and treatment are of utmost importance in reducing the severity of long term sequelae of this syndrome. This report presents a rare event of Gorlin-Goltz syndrome occurring in a 39-year-old male and his 8-year-old daughter. The clinical and investigative features of this familial disorder has been described in detail.

Non-syndromic recurrent multiple odontogenic keratocysts: a case report

Odontogenic keratocysts (OKCs) are one of the most frequent features of nevoid basal cell carcinoma syndrome (NBS). It is linked with mutation in the PTCH gene. Partial expression of the gene may result in occurrence of only multiple recurring OKC. Our patient presented with nine cysts with multiple recurrences over a period of 11 years without any other manifestation of the syndrome.