Sokol, LenaLenaSokol0000-0001-5416-5044Kölzer, ViktorViktorKölzer0000-0001-9206-4885Rau, TilmanTilmanRau0000-0002-1251-950XKaramitopoulou Diamantis, EvanthiaEvanthiaKaramitopoulou DiamantisZlobec, IntiIntiZlobec0000-0001-6741-3000Lugli, AlessandroAlessandroLugli0000-0002-9264-51852024-10-232024-10-232015https://boris-portal.unibe.ch/handle/20.500.12422/135564BACKGROUND Tapasin is a crucial component of the major histocompatibility (MHC) class I antigen presentation pathway. Defects in this pathway can lead to tumor immune evasion. The aim of this study was to test whether tapasin expression correlates with CD8(+) cytotoxic T lymphocyte (CTL) infiltration of colorectal cancer (CRC) and overall survival. METHODS A next-generation tissue microarray (ngTMA) of 198 CRC patients with full clinicopathological information was included in this study. TMA slides were immunostained for tapasin, MHC I and CD8. Marker expression was analyzed with immune-cell infiltration, patient survival and TNM-staging. RESULTS A reduction of tapasin expression strongly correlated with venous invasion (AUC 0.682, OR 2.7, p = 0.002; 95% CI 1.7-5.0), lymphatic invasion (AUC 0.620, OR 2.0, p = 0.005; 95 % CI 1.3-3.3), distant metastasis (AUC 0.727, OR 2.9, p = 0.004; 95% CI 1.4-5.9) and an infiltrative tumor border configuration (AUC 0.621, OR 2.2, p = 0.017; 95% CI 1.2-4.4). Further, tapasin expression was associated with CD8(+) CTL infiltration (AUC 0.729, OR 5.4, p < 0.001; 95% CI 2.6-11), and favorable overall survival (p = 0.004, HR 0.6, 95% CI 0.42-0.85). CONCLUSIONS Consistent with published functional data showing that tapasin promotes antigen presentation, as well as tumor immune recognition and destruction by CD8(+) CTLs, a reduction in tapasin expression is associated with tumor progression in CRC.en500 - Science::570 - Life sciences; biology600 - Technology::610 - Medicine & healtharticle10.7892/boris.723612631056810.1186/s12967-015-0647-1