Expression of candidate biomarkers in human testicular germ cell tumor

Abstract

Tumori zametnih stanica testisa (TGCT, od eng. testicular germ cell tumor) su heterogena skupina neoplazmi koja se dijeli na seminome i neseminome. Često se javljaju kao miješani tumori zametnih stanica. U svrhu postavljanja precizne dijagnoze i detekcije prisutnosti određenog histološkog podtipa, koriste se biomarkeri kao reproducibilni izvor objektivne informacije o zdravstvenom stanju pacijenta. Cilj ovog diplomskog rada bio je istražiti specifičnost antigena OCT3/4 (gen POU5F1) i TDGF1 (gen TDGF1) na pojedine komponente TGCT-a i njihov potencijal kao dijagnostičkih biomarkera. Metode koje sam koristio su histološko bojenje, imunohistokemija i statistička obrada podataka. Nakon što sam histološki obojio rezove tkiva hemalum-eozinom, klinički patolog je utvrdio prisutnost i tip pojedinih komponenti unutar parafinskih uzoraka tkiva. Imunohistokemijskim bojenjem rezova tkiva iz istih histoloških blokova, analizirana je ekspresija gena od interesa na proteinskoj razini. Kvantifikaciju signala u pojedinoj TGCT komponenti proveo je klinički patolog, nakon čega sam proveo statističku obradu podataka. Rezultati su ukazali na značajnu razinu ekspresije antigena OCT3/4 u stanicama embrionalnog karcinoma, seminoma i neoplazije zametnih stanica in situ, te TDGF1 u stanicama embrionalnog karcinoma, teratoma i neoplazije zametnih stanica in situ. Kombinacijom bojenja na oba antigena može se razlikovati prisutnost seminoma u tkivima bojanim s OCT3/4 i teratoma u tkivima bojanim s TDGF1.Testicular germ cell tumors (TGCT) are a heterogeneous group of neoplasms that are divided into seminomas and nonseminomas. Often, they occur as mixed germ cell tumors. In order to make an accurate diagnosis and detect the presence of a certain histological subtype, biomarkers are used as a reproducible source of objective information about the patient's health status. The aim of this thesis was to investigate the specificity of the antigen OCT3/4 (gene POU5F1) and TDGF1 (gene TDGF1) on individual components of TGCT and their potential as diagnostic biomarkers. The methods I used were histological staining, immunohistochemistry, and statistical data processing. After histological staining of tissue sections with hemalum-eosin, a clinical pathologist determined the presence of individual component within the paraffin tissue samples. By immunohistochemical staining of tissue sections from the same histological blocks, analysed was expression of genes of interest at the protein level. Signal quantification in each TGCT component was performed by a clinical pathologist, after which I statistically processed the data. The results indicated a significant expression level of antigen OCT3/4 in cells of embryonal carcinoma, seminoma, and germ cell neoplasia in situ, and TDGF1 in cells of embryonal carcinoma, teratoma, and germ cell neoplasia in situ. The combination of staining for both antigens can distinguish the presence of seminoma in OCT3/4-stained tissues and teratoma in TDGF1-stained tissues