Expression of c-Jun, p73, Casp9, and N-ras in thymic epithelial tumors: relationship with the current WHO classification systems

BACKGROUND To evaluate the expression and differential significance of c-Jun, p73, Casp-9 and N-ras in thymic epithelial tumors (TETs) with the aim to provide useful information for tumor biology and prospective therapy. METHODS In this study, we analyzed the expression of four chromosome 1-related genes, namely c-Jun, p73, Casp-9 and N-ras, in 60 cases of thymic epithelial tumors. The tumors included 52 thymomas and 8 thymic carcinomas which were categorized according to the current WHO classification systems. RESULTS Compared with the normal thymus tissue, all thymic epithelial tumors demonstrated higher expression of c-Jun and p73. The expression of c-Jun and p73 in type B2, B3 thymoma and thymic carcinomas was similar, and significantly higher than that in all other subtypes of thymomas. Unlike type A thymoma, the expression of Casp-9 was relatively lower in type B thymoma and thymic carcinomas. With respect to the clinical staging systems, c-Jun was more expressed in progressive tumors harboring higher stages. In contrast to c-Jun, p73 and Casp-9, there was no significant aberration with N-ras expression irrespective of either tissue or tumor types. CONCLUSIONS The overexpression of c-Jun, p73 and Casp-9 in thymic epithelial tumors is closely related with the pathogenesis and biological behavior of the neoplasms. These candidate biomarkers provided useful information for prospective personalized therapy in the clinical management. VIRTUAL SLIDES http://www.diagnosticpathology.diagnomx.eu/vs/1521774814749726.