Immunohistochemical study of P53 protein expression in different prostate cancer Gleason grading groups

Prostate cancer (PC) remains an urgent public health problem, especially in developed countries. The use of immunohistochemical research methods in addition to the morphological classification of prostate adenocarcinomas allows a more accurate diagnosis and prognosis of the disease. The aim of the study is to identify isoforms of P53 using clones of mouse antibodies (D-07 and Y5; Epitomics, USA) in prostate cancer with different proliferative activity and the degree of malignancy. Materials and Methods: The work included surgical material for prostate resection and prostatectomy, as well as biopsy specimens (56 cases in total). An immunohistochemical study was carried out with the Ki-67 marker, as well as with mouse monoclonal antibodies (D-07 and Y5) to the P53 protein, interacting with its “wild” and mutant isoforms. The significance of the difference in the samples was determined using the Mann-Whitney U-test, correlation relationships were determined using the Spearman coefficient. Results: Expression of P53 upon interaction with antibodies D-07 and Y5 was determined in 56.3% and 39.6%, respectively. A statistically significant direct correlation was found between the severity of P53 expression when interacting with Y5 antibodies and the degree of tumor differentiation (rs = 0.567, p <0.05), as well as between the expression level of this protein and tumor proliferative activity (rs = 0.698, p <0.05). Conclusion: Antibodies of clone D-07, interacting with both wild and mutant isoforms of P53 protein, show positive expression in adenocarcinomas of all degrees. Expression of the mutant P53 protein is most pronounced in low-differentiated carcinomas and correlates with high proliferative activity of tumor cells, which may be associated with a loss in the induction of P53-dependent apoptosis.