P16 and caprin-1 expressions in odontogenic keratocysts and dentigerous cysts

Objective: The aim of the work described in this thesis is to compare dentigerous cysts and odontogenic keratocysts for CAPRIN-1 and p16 antibodies via immunohistochemical staining and to obtain a new perspective about the specific behavioral characteristics of odontogenic keratocysts at the molecular level. Method: Forty dentigerous cyst and forty odontogenic keratocyst cases, operated between 2014 and 2019, were randomly selected and examined using immunohistochemical staining for the detection of CAPRIN-1 and p16 antibodies. Nuclear and/or cytoplasmic staining was evaluated as "positive". In positive cases, the cell staining rate (expressed as a percentage) and the cell staining intensity were determined and a staining intensity distribution (SID) score was calculated for each sample. Cases were considered "negative" if they showed no staining for CAPRIN-1 or p16 antibodies and they were given a SID score of zero. According to the SID scores, the expression levels were rated as negative, mild, moderate or high. Results: Of the 80 samples, 16 were excluded from the study for reasons of impaired epithelial integrity or inflammation that could adversely affect the immunohistochemical evaluation. Fourteen negative, 17 positive p16 expression and 15 negative, 18 positive p16 expression were observed in dentigerous cyst and odontogenic keratocyst groups, respectively. The difference between the negative and positive cases within groups was not significant. SID score range and mean were 0-120 and 16.9 (± 30.9) for dentigerous cysts and 0-180 and 14.8 (± 33.6) for odontogenic keratocysts. The difference between the SID scores was not statistically significant between groups. Ten negative, 21 positive and three negative, 30 positive CAPRIN-1 expression were observed in dentigerous cyst and odontogenic keratocyst groups, respectively. The difference between the negative and positive cases within groups was significant only in the odontogenic keratocyst group (p = 0.000). The SID score range and mean were 0-160 and 31.1 (± 35.7) for dentigerous cysts and 0-160 and 57.3 (± 42.3) for odontogenic keratocysts. CAPRIN-1 expression was significantly higher in the odontogenic keratocyst group (p = 0.043). Conclusion: The molecular basis of characteristic features such as increased mitotic activity, high recurrence rates or presence of satellite cysts in odontogenic keratocysts may be attributed to the expression of CAPRIN-1.