Activation of anti-apoptotic machinery downstream to Fas/FasL pathway in primary mixed and pure mucin producing cholangiocarcinoma cells: key role of c-FLIP

Cholangiocarcinoma (CCA) comprises a heterogeneous group of malignancies lacking of effective strategies for prevention and cure. Recently, we have established a protocol for the isolation of primary cells from mixed and mucin specimens of human CCA. To this regard, the aim of this study was to analyze the influence on proliferation and apoptosis as well as the related modifications of apoptotic machinery downstream to Fas/FasL pathway in primary cultures of human mixed and mucin-producing CCA after direct co-culture with peripheral blood mononuclear cells (PBMCs). Our findings show that both IH-CCA subtypes constitutively express high levels of Fas and FasL. Following direct co-culture with PBMCs, the expression of Fas and FasL significantly increased after 24, 48 and 72 hours of exposure (p< 0.05). At the same time, a significant increase of percentage of apoptotic CD4+ and CD8+ T-cells or Natural Killer CD56+ cells was observed along the co-cultures compared to PBMCs cultured alone (