colonic polyps: immunohistochemical study of proliferation and apoptosis. Zaporizhzhya state medical university, Zaporizhzhya, Ukraine ABSTRACT. Background. It's well known that colonic polyps can be precursors of colorectal cancer. But exact immunohistochemical parameters, including proliferation and apoptosis levels of polyps' cells, that may have prognostic value, still not known. Objective. To study the features of immunohistochemical expression of proliferation and apoptosis markers by distal colonic polyps' cells. Methods. Pathomorphological and immunohistochemical studies of biopsies of distal colonic polyps from 30 patients (the age ranged from 41 to 83 years) were carried out. Results. Distal colonic polyps are characterized by the medium proliferation level of epithelial cells [Me=62.40% (48.65; 76.23) for adenomas, Me=26.23% (22.19; 48.88) for hyperplastic polyps], the low proliferation level of stromal cells [Me=2.94% (1.23; 4.35) for adenomas, Me=1.18% (1.10; 1.86) for hyperplastic polyps], the low p53 expression level of epithelial and stromal cells [Me=2.39% (1.58; 8.26) and Me=1.23% (0.72; 1.49) for adenomas' cells, Me=0,00% (0,00; 1,47) and Me=0,00% (0,00; 0,05) for hyperplastic polyps' cells], and also by the low apoptosis level of epithelial and stromal cells [Me=31.84CUOD (19.53; 42.34) and Me=43.87CUOD (25.47; 73.09) for adenomas, Me=16.99CUOD (11.86; 39.85) and Me=28.64CUOD (19.20; 30.71) for hyperplastic polyps]. There are direct correlations between the expression levels of proliferation and apoptosis markers and also the dysplasia grade of the distal colonic adenomas: between the Ki-67 expression levels of epithelial and stromal cells and also the dysplasia grade (γ=0.65 and γ=0.70, respectively), between the p53 expression level of epithelial cells and the dysplasia grade (γ=0.53), between the caspase-3 expression levels of epithelial and stromal cells and also the dysplasia grade (γ=0.80 and γ=0.63, respectively). Moreover, there are direct correlations between the expression levels of proliferation and apoptosis markers of distal colonic polyps' epitheliocytes: between the Ki-67 and p53 expression levels (r=0.71 for adenomas, r=0.79 for hyperplastic polyps), between the Ki-67 and caspase-3 expression levels (r=0.61 for adenomas), between the p53 and caspase-3 expression levels (r=0.59 for adenomas, r=0.79 for hyperplastic polyps). Conclusion. These data indicate the close association between the processes of proliferation, accumulation of p53 protein, and apoptosis of the distal colonic polyps' cells.

Introduction. Serrated polyps are newly distinguished types of colonic polyps.Nowadays lots of questions about serrated neoplastic pathway are still unclear. The purpose of the study was to compare Ki-67 and CD44 immunohistochemical (IHC) expression levels in different histological types of serrated polyps. Materials and methods. Histopathological and IHC studies of 30 serrated polyps were conducted. IHC study was carried out using antibodies against Ki-67 and CD44. Results of IHC reactions with antibodies against Ki-67 were estimated by immunostained nuclei counting and were expressed in proliferation index (PI) while results of IHC reactions with antibodies against CD44 were estimated by photo digital morphometry and were expressed in immunostained cells relative area (%). Furthermore, distribution of Ki-67+ and CD44+ cells in colonic crypts was examined. 359Results. It was revealed that hyperplastic polyps (HP) were characterized by medium PI and basal-middle pattern of Ki-67+ cells distribution. HP were also characterized by the median of CD44+ cells area equal to 22,36 (13,15;30,41) % and basal-middle pattern of CD44+ cells distribution. Herewith, direct medium strength correlation between Ki-67 and CD44 expression levels in HP was established. Traditional serrated adenomas (TSA) were characterized by medium PI and diffuse pattern of Ki-67+ cells distribution. TSA were also characterized by the median of CD44+ cells area equal to 25,48 (15,19; 29,04) % and uppermiddle pattern of CD44+ cells distribution. Direct weak strength correlation between Ki-67 and CD44 expression levels in TSA was established. Sessile serrated adenomas (SSA) were characterized by medium PI and basal pattern of Ki-67+ cells distribution. SSA were also characterized by the median of CD44+ cells area equal to 20,54 (11,25;28,15) % and basalmiddle pattern of CD44+ cells distribution. Direct medium strength correlation between Ki-67 and CD44 expression levels in SSA was established.

Introduction. Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide. Studying invasion and metastasizing mechanisms in colorectal carcinogenesis is gaining momentum. The purpose of the study was to analyze immunohistochemical (IHC) expression levels of epithelial and mesenchymal phenotypic markers, as well as cancer stem cells markers on I-IV (pTNM) stages of CRC. Materials and

Annotation. ЕpCAM is known as a universal stem cell marker, however, the question of its value in colorectal cancerogenesis is still open. The aim of the research was to compare EpCAM immunohistochemical expression levels in polyps and adenocarcinoma of the distal colon. Pathohistological and immunohistochemical studies of biopsies of polyps and non-changed mucosa of 40 patients, as well as surgical material of 30 patients that underwent surgical treatment of colorectal cancer were carried out. The data were statistically processed using the STATISTICA® for Windows 13.0 package (StatSoft Inc., license № JPZ804I382130ARCN10-J). The median (Me), the lower and upper quartiles (Q1; Q3) were calculated, the comparison between the two groups of observations was performed using the Mann-Whitney test. It was figured out that the polyps are characterized by membranous pattern of EpCAM expression by epitheliocytes with the median equal to 65.22 (33.65; 78.94) CUOD. Comparative analysis of EpCAM expression levels in the polyps and histologically non-changed mucosa, as well as in two studied subgroups of the polyps revealed no significant differences. Colorectal adenocarcinoma is characterized by membranous-cytoplasmic pattern of EpCAM expression by cancer cells with the median equal to 90.86 (80.24; 99.02) CUOD. Comparative analysis of EpCAM expression levels in studied subgroups of the carcinoma (subgroups that correspond to the pTNM stages) revealed the tendency to increasing of EpCAM expression by cancer cells with statistically significant growth of the expression level median during the progression of the tumor from II to IV stages. Furthermore, it was established that the median of EpCAM expression is 28 % higher than the median of the marker expression in the polyps that is statistically significant: 90.86 (80.24; 99.02) CUOD vs. 65.22 (33.65; 78.94) CUOD, р˂0.05. Based on the data obtained, the difference in the patterns of EpCAM expression in the polyps and colorectal carcinoma is due to structural changes that happens to the molecule during colorectal carcinogenesis, moreover, significant increasing of EpCAM expression level at advanced stages of colorectal carcinoma reflects the acquisition of stemness by cancer cells.

Introduction. Immunohistochemical prognostic markers are promising direction for a search. The purpose of the study was analyze ALDH1 immunohistochemical expression in different histological types of serrated polyps of the distal colon. Materials and methods.Histopathological and IHC studies of 30 serrated polyps were conducted. IHC study was carried out using antibodies against ALDH1. Results of IHC reactions were estimated by photo digital morphometry and were expressed in immunostained cells relative area (%).Results. Hyperplastic polyps are characterized by the median of ALDH1+ stromal cells relative area equal to 15,08 (11,12;21,46) % and the median of ALDH1+ epitheliocytes relative area equal to 18,28 (10,14;26,15) %. The basal-middle pattern of ALDH1+ cells distribution was revealed. Traditional serrated adenomas are characterized by the median of ALDH1+ stromal cells relative area equal to 25,63 (18,26;30,42) % and the median of ALDH1+ epitheliocytes relative area equal to 22,13 (17,22;36,05) %. The upper-middle