Determination of the levels of expression of sarcolectin and calcyclin andof the percentages of apoptotic but not proliferating cells to enable distinction between recurrent and nonrecurrent cholesteatomas

Objectives,, To investigate in a series of cholesteatomas 1. whether subgro ups of cholesteatomas with specific proliferative/apoptotic features exhibi t distinct differentiation markers and 2 whether these different subgroups identified at the biological level relate to specific groups of clinically identified cholesteatomas. Study Design: Analysis of 55 cholesteatomas rese cted by the same surgeon, by means of canal wall up and canal wall down sur gical procedures. Methods: Two differentiation markers were used: biotinyla ted sarcolectin (to identify sarcolectin-binding sites) and a monoclonal an tibody directed against calcyclin (which is the S100A6 protein). The growth pattern in cholesteatomas was characterized at three distinct levels: 1, t he cell proliferation level determined by means of the MIB-1 antibody, whic h enables the Ki-67 cell-cycle-related antigen to be identified on archival material; 2 the apoptosis level determined by means of the in situ labelin g of nuclear DNA fragmentation (TUNEL staining); and 3, the p53 tumor suppr essor gene-related product determined by means of p53 immunohistochemistry. Results: The cholesteatomas that exhibited the highest proportion of apopt otic cells were those which exhibited the highest level of sarcolectin-bind ing sites (i.e., sialic acids). In contrast, the cholesteatomas exhibiting the lowest level of both proliferation and apoptosis showed the highest lev el of calcyclin. Recurrent cholesteatomas can be identified from nonrecurre nt ones on the basis of three features, namely, the level of apoptotic cell s, the way in which the apoptotic cells are distributed (i,e,, homogeneousl y vs. heterogeneously), and the percentage of calcyclin-positive cells. Con clusions: The present data emphasize the existence of distinct subgroups of cholesteatomas identifiable at both cell kinetic and differentiation level s. Some of the biological variables used here to identify distinct biologic al subgroups of cholesteatomas in turn enabled some biological variables to be identified, so making it possible to classify the cholesteatomas in ter ms of recurrence versus nonrecurrence.