Differential rates of proliferation and apoptosis in nasal polyps correspond to alterations in DNA spatial distribution and nuclear polarization as observed by confocal microscopy

Abstract

The study aimed to investigate the expression of p53, Bcl-2 and Ki-67 in relation to the histologic and nuclear qualitative and spatial characteristics of chronic rhinosinusitis with polyposis (CRP). Imprint smears obtained from surgically removed nasal polyps of 20 patients were studied. The polyps were classified according to their histological characteristics as: hyperplasia (simple and pronounced) and squamous metaplasia. The expression of p53, Bcl-2 and Ki-67 was assessed by immunocytochemistry. DNA spatial distribution and nuclear orientation were studied by staining with propidium iodide and examined by confocal microscopy. Positive immunoreaction for p53, Ki-67 and Bcl-2 was observed in 50, 65, and 50% of polyp's smears, respectively. For each diagnosis, the rates were simple hyperplasia 60, 80 and 30%, pronounced hyperplasia 80, 100 and 40%, metaplasia 0, 0 and 100%, respectively. Abnormal chromatin distribution and nuclear disorientation was observed in three cases of pronounced hyperplasia combined with positive immunoreaction for Ki-67 and p53 and negative immunoreaction for Bcl-2. CRP demonstrated different proliferation and apoptotic rates, according to their histology. Nuclear characteristics observed by confocal microscopy are associated with the immunocytochemical markers of proliferation and apoptosis.