Analysis of the anti-apoptotic protein bcl-2 in oral squamous cell carcinoma

Abstract

Aim: The aim of this study was to analyze the presence of the anti-apoptotic protein bcl-2 in oral squamous cell carcinoma and determine its potential role in the development and progression of this type of tumor. Materials and methods: The expression of bcl-2 was determined in 28 paraffin blocks of oral squamous cell carcinoma using the immunohistochemical method. The percentage of the immuno-reactive cells in positively stained tumor regions was determined using the microscopic analysis and Ozaria software. Results: Positive immunohistochemical test was observed in 19 out of 28 samples (68%) as follows: in 11 samples there was a low (+), in four a moderate (++) and in the last four a high percentage (+++) of stained cells. In the group of patients at the low stage of the disease (T2), 50% of tumor samples showed bcl-2 protein expression whereas in the higher stages (T3 and T4) of positively stained samples, this percentage was 67%. There was a trend of an increasing number of cells with positive bcl-2 staining in the tumors of higher clinical stages but not the level of bcl-2 protein expression. Conclusion: Both parameters, the presence of bcl-2 staining and the percentage of cells with bcl-2 immunoexpression, may act as additional prognostic parameters that indicate an increased proliferative tumor potential.

Cilj ove studije bio je analiza prisustva antiapoptotskog proteina bcl-2 u skvamocelularnom karcinomu usne regije i procena njegove eventualne uloge u razvoju i progresiji ove vrste tumora. Materijal i metode: Na uzorku od 28 parafinskih blokova skvamocelularnog karcinoma usne regije, imunohistohemijskom metodom ispitan je ekspresioni status bcl-2 proteina. Mikroskopskom analizom i primenom softvera- Ozaria određen je procenat imunoreaktivnih ćelija u pozitivno obojenim tumorskim regijama. Rezultat: Pozitivnu imunohistohemijsku obojenost pokazalo je 19 od 28 uzoraka (68%) i to: 11 je bilo sa niskim (+), 4 sa srednjim (++) i 4 sa visokim procentom (+++) obojenih ćelija. U grupi pacijenata niskog stadijuma (T2) 50 % uzoraka tumora je pokazivalo ekspresiju bcl-2 proteina dok je u višim stadijumima (T3 i T4) pozitivnih uzoraka bilo 67%. Postojao je trend porasta broja ćelija sa pozitivnom bcl-2 obojenošću kod tumora u višim kliničkim stadijumima, ali ne i povećan nivo ekspresije bcl-2 proteina. Zaključak: Oba parametra, prisustvo bcl-2 obojenosti i procenat ćelija sa bcl-2 imunoekspresijom, mogu predstavljati dopunske prognostičke parametre koji ukazuju na povećan proliferativni potencijal tumora.