A PILOT STUDY OF SELECT CELL CYCLE MARKERS IN GLANDULAR ODONTOGENIC CYSTS

Objectives Glandular odontogenic cysts (GOCs) and dentigerous cysts (DCs) differ significantly in their biologic behavior. One third of GOCs have been reported to recur whereas recurrence is rare in DCs. Due to the apparent growth potential of GOCs, we evaluated and compared the presence of cell cycle markers such as cyclin D1, p53, p16, p27, Rb, and BCL-2. Findings Eight GOCs and a control group of three DCs were included in the pilot study. All GOCs possessed seven or more of the required features. Interestingly, we detected strong expression of Cyclin D1, a regulatory protein required for cell cycle progression, within the basilar and parabasilar layers of the cyst epithelium for GOCs and scattered positivity correlating with the level of inflammation in DCs. Expression of tumor suppressor proteins, p27 and p16, were notably different between the two cysts. For p16, the superficial layers were strongly and diffusely positive in GOCs while the basilar and parabasilar layers were essentially negative. DCs showed a patternless distribtion of p16 staining with variable intensity throughout the epithelium. The majority GOCs exhibited full thickness expression of p27 whereas DCs demonstrated scattered and weak positivity. With p53, BCl-2, and Rb, minimal appreciable difference was noted in the staining pattern and intensity between GOCs and DCs. Conclusions Our results revealed differential staining patterns between DCs and GOCs for the following cell cycle markers: Cyclin D1, p16, p27. Based on our staining pattern, we also hypothesize that the proliferation potential of the basal and parabasilar layers of the epithelium in particular contribute to the growth and high recurrence rate for GOCs. Our findings suggest that cell cycle disturbances exist in GOCs and may contribute to the aggressiveness of their biological behavior. Additional studies with an expanded cohort are required to confirm these initial findings and provide further insights.