engleski

Analysis of protein expression- possible panel for TGCT diagnostics

Testicular germ cell tumor (TGCT) represents only 1% of all malignancies. However, it affects the young male population, thereby decreasing the quality of their reproductive health. TGCT is divided into seminomas(SE) and nonseminomas(NS). The Iatter group consists of four histologically different types, i.e. embryonal carcinoma (EC), teratoma (TE), yolk sac tumor (YST) and choriocarcinoma (CH). SE and NS, as well as types of NS, differ in their aggressiveness, therapy strategy and response to treatment, which makes a precise diagnosis crucial. In this study, protein expression of OCT4 was compared with SALL4. OCT4 is a marker already used in TGCT diagnostics, while SALL4 was reported as a novel sensitive marker. Therefore the aim was to analyze the expression of these genes in TGCT components, germ cell neoplasia in situ (GCNIS) and seminiferous tubules with preserved spermatogenesis (ST). In total 117 TGCT samples were cut to 4 pm slides and immunohistochemically analyzed. Morphometricanalysis of protein expression was performed by a pathologist and the results were statistically analyzed. Semi- quantification of protein expression was expressed by immunoreactivity score (IRS). To calculate diagnostic positivity a cut—off value of IRS was 4, i.e. IRS score 0—3 is considered negative, while IRS 24 was declared positive. The highest protein expression of both genes was detected in GCNIS. |n TGCT both OCT4 and SALL4 were expressed. Considering SE and NS, both genes were highly expressed in SE compared to whole NS group. Considering NS components, OCT4 was expressed only in EC. SALL4 was highly expressed in EC and YST while in CH and TE its expression was absent or low. Based on the obtained results, we are able to suggest a panel which could be used in the diagnosis of NS components. Joined protein expression of OCT4 and SALL4 differ between EC (OCT4+, SALL4 +) and YST (OCT4 -, SALL4+). The absence of SALL4 protein could point to CH and TE. In the differential diagnosis of SE and EC/YS those two markers alone are not helpfull. In conclusion, investigating protein expression ofjust one gene is not enough for diagnostic of either TGCT or TGCT components. However, protein expression analysis of SALL 4 and OCT 4 as a panel could have potential use in TGCT diagnostics.

protein expression ; TGCT ; diagnostic panel

nije evidentirano