MCM-2 an alternative to Ki-67 for assessing cell proliferation in odontogenic pathologies

Abstract

Objective: New proliferative marker MCM-2 can be observed in all phases of cell cycle and plays a central role in chromatin replication. At present limited information exists on the expression of MCM-2 in odontogenic pathologies (OP). Hence, the purpose was to assess the expression of Ki-67 and MCM-2 in clinically significant OP and to evaluate the relation between these markers and the clinical-imaging-pathologic characteristics of ameloblastoma (AM) and odontogenic keratocyst (OKC). Materials and Methods: Clinical-imaging-pathologic characteristics of thirty consecutive cases of AM and thirty OKC were tabulated and sections were subjected to immunostaining for Ki-67 and MCM-2. The quantitative data was subjected to One Way Anova, Tukeys multiple posthoc procedures, independent t-test, paired ttest and Pearson’s correlation test. Results: Proliferative index (PI) was significantly higher with MCM-2 than Ki-67 in AM and OKC. PI with Ki-67 and MCM-2 in AM was significantly higher in peripheral than the central cells. PI with Ki-67 and MCM-2 in OKC was significantly higher in suprabasal than the basal cells. PI with Ki-67 or MCM-2 in AM and OKC did not show a statistically significant difference. MCM-2 in AM showed a significant association with type of radiolucency and nature of lesion. Ki-67 in OKC showed a significant association with number of lesion and type of radiolucency. Conclusions: MCM-2 is a more sensitive marker for assessing the growth rate, and may be appropriate in sorting the proliferative fraction than Ki-67. Comparable expression of proliferative markers in AM and OKC clarifies their nature, indicating identical aggressive character.