J of IMAB. 2024 Jan-Mar;30(1) https://www.journal-imab-bg.org 5339 Original article IMMUNOHISTOCHEMICAL EXPRESSION OF NGF/TRKA AND BDNF/TRKB IN TUMOR PARIENCHYMA AND PERIPROSTATIC ADIPOSE TISSUE, DEPENDING ON THE PATHOANATOMIC STAGE OF PROSTATE CANCER Nikolay Evtimov 1, 2 1) Department of Urology, Faculty of Medicine, Medical University Varna, Bul- garia, 2) MHAT ”St. Anna” Varna, Bulgaria. Journal of IMAB. 2024 Jan-Mar;30(1) Journal of IMAB ISSN: 1312-773X https://www.journal-imab-bg.org ABSTRACT Introduction: For more than 30 years, the idea of inhibiting growth factors has taken over the minds of dif- ferent generations of scientists since the progression of the neoplastic process is determined by uncontrolled prolifera- tion differentiation and apotosis and the metastasis of the neoangiogenesis process. The aim: of this work is to show the density of im- munohistochemical expression of NGF/TrkA and BDNF/ TrkB A Trk B in tumor parienchyma and periprostatic adi- pose tissue. The study ability is to use it as a prognostic indicator for metastasis of prostate cancer. Material and methods: During the period 2018- 2022, 184 patients were diagnosed with radical prostateectomy on the occasion of localized prostate can- cer with PSA < or > 20 nmoll/ml, Gleason< or >7, G< or >II. study of the density of expression besch determined by a semi-quantitative method and was established by counting epithelial cells associated with a monocronal an- tibody, calculated on 20 fields. Results: The study showed expression of Trk receptors in epithelial cells in all tissue samples. NGF/ TrkA has poor expression in adipose tissue in areas perirectally and ventrally in the pathoanatomical stage G1, and it becomes moderately positive as the process of undifferentiation progresses. The same tendency is observed in the expression of neurotrophin in prostate-epithelial cells. Conclusions: The increased density of NGF, as well as the preoperative determination of the expression of BDNF and TrK a,b receptors in the pathoantomic prepara- tion, can be used as a negative prognostic indicator of the aggressiveness of the CaP tumor, as well as its possible me- tastasis. Keywords: pathogenesis of prostate cancer, immu- nohistochemistry, growth factors, NGF, BDNF, INTRODUCTION: Prostate cancer is the most common diagnosis of malignant neoplasms in the male population. With age, the possibility of developing prostate cancer increases. [1] We know that all growth factors can be synthesized by vari- ous mature and embryonic cells. [2]. In addition to EGF, other growth factors are isolated. Fibroblast growth factor (FGF), transforming growth factor (TGF-á.â) EGF, and bFGF promoting cell division [3] are separated from the ventral part of the prostate while transforming growth factor (TGF- beta) inhibits proliferation (Nikajaer et al. 2012). The ini- tial lesions in the prostate are due to fibromuscular nodes. Therefore, in order to clarify the cause of BPH and the for- mation of lesions in malignant degeneration, efforts should be directed to studying changes in the interaction between stroma and epithelial cells of the prostate gland [4-6]. While the role of EGF, BFGF, KGF, TGF-beta has been stud- ied, no studies documenting the expression of NGF and BDNF in both the prostate and the main paracrine organ in the human bode–adipose tissue – have been described in the literature [6-8]. We know that all growth factors can be synthesized by various mature and embryonic cells. In the prostate, the main growth factor is the epidermal growth factor [9]. Pros- tate-specific antigen is produced only by the epithelial cells of the gland, so in epithelial hyperplasia, serum PSA levels are increased in contrast to stroma hyperplasia since epidermal growth factor, which is directly influenced by DHT (dehydrotestosterone) directly induces cell prolifera- tion and differentiation of epithelial prostate cells [10-12]. From the accumulated literature on the expression of NGF and BDNF in both the prostate and the main paracrine organ in the human body – adipose tissue, there are very few studies. Based on this, we suggest that nerve growth factor (NGF) should play a fundamental role in the pathogenesis of prostate cancer. We propose that BPH and PC is a development of the same disease, but the different manifestation of the dis- ease is influenced by different genetic and epigenetic fac- tors. Nerve growth factor – as a protein secreted by stro- https://doi.org/10.5272/jimab.2024301.5339