Wingless-type Protein-1 (Wnt-1) Expression in Primary Conventional and Unicystic Ameloblastomas and Their Recurrent Tumors

Evaluation of Expression of WNT1 and PTCH Genes in Peripheral Blood of Patients with Odontogenic Cysts and Tumours of the Jaws by Quantitative RT-PCR: A Pilot Study

Introduction

Odontogenic lesions of the maxillofacial region constitute a complex group of lesions with diverse histopathologic types and clinical behaviour. Early diagnosis is important to minimize the need for radical surgery and to improve quality of life of the patients. Tumour markers play an essential role in the molecular level understanding of Odontogenic lesions and also used for early diagnosis and target therapies which improves the quality of life of the patients. Patched, a tumour suppressor gene encodes the transmembrane protein PTCH and is a receptor for the morphogen Sonic Hedgehog. It is evident that PTCH gene mutations occur in odontogenic keratocysts and the Hedgehog signalling pathway has an important role during tooth formation. WNT 1 is a key signal molecule that controls cell growth and proliferation. WNT pathway abnormalities are reported to induce tumour occurrence. Hence, my study was to determine the presence of WNT1 and PTCH in peripheral blood of patients with Odontogenic lesions using quantitative RT-PCR.

Materials and Methods

In this cross-sectional study, two groups were included: Group 1-blood samples from 8 individuals with odontogenic cysts and tumours, and Group 2-blood samples of 8 individuals without Odontogenic lesions. 2 ml of blood sample was collected from radial veins into PAX gene tubes containing RNA stabilizing agent and stored at a temperature of 2 to 4 degrees and transported to Enable Biolabs India Pvt Ltd., Chennai. PAX gene tubes were subjected to centrifugation at 8000 rpm to separate plasma fraction. Reverse transcription of mRNA was performed using miScript II RT Kit (Cat#218161, Qiagen, Germany) to synthesize cDNA. GAPDH house-keeping gene used as control.

Results

The study group had 3 males and 5 females (n = 8) with a mean age group of 32.6 years and the control group had 2 males and 6 females (n = 8) with mean age of 35.2 years. Group I (study group) showed 37.5% positive expression of WNT1 gene with a p value of 0.055 (p > 0.05) and 50% positive expression of PTCH with a p value of 0.021 (p < 0.05) (Figs. 3 and 4) which was statistically significant when compared with control group. Group II (control group) showed 100% negative expression for WNT1 and PTCH genes.

Conclusion

WNT1 and PTCH genes were expressed in peripheral blood of patients with odontogenic lesions. WNT1 and PTCH genes may be potential predictors in individuals who would develop odontogenic lesions. Further studies on expression of WNT1 and PTCH genes with larger number of samples might give a future scope for target therapy in odontogenic lesions.

Notch signaling and ghost cell fate in the calcifying cystic odontogenic tumor

Notch signaling is an evolutionarily conserved mechanism that enables adjacent cells to adopt different fates. Ghost cells (GCs) are anucleate cells with homogeneous pale eosinophilic cytoplasm and very pale to clear central areas (previous nucleus sites). Although GCs are present in a variety of odontogenic lesions notably the calcifying cystic odontogenic tumor (GCOT), their nature and process of formation remains elusive. The aim of this study was to investigate the role of Notch signaling in the cell fate specification of GCs in CCOT. Immunohistochemical staining for four Notch receptors (Notch1, Notch2, Notch3 and Notch4) and three ligands (Jagged1, Jagged2 and Delta1) was performed on archival tissues of five CCOT cases. Level of positivity was quantified as negative (0), mild (+), moderate (2+) and strong (3+). Results revealed that GCs demonstrated overexpression for Notch1 and Jagged1 suggesting that Notch1Jagged1 signaling might serve as the main transduction mechanism in cell fate decision for GCs in CCOT. Protein localizations were largely membranous and/or cytoplasmic. Mineralized GCs also stained positive implicating that the calcification process might be associated with upregulation of these molecules. The other Notch receptors and ligands were weak to absent in GCs and tumoral epithelium. Stromal endothelium and fibroblasts were stained variably positive.