TRAIL Expression On Lymphocyte From The Patients Of Melanoma Friend Or Foe?

Background: Melanoma has long been regarded as a model human cancer to study responses against tumors due to its strong immunity responses. Previous study shows that CD4~+ T cell infiltrates are associated with regression of primary melanoma and with response to treatment with interferon- α 2. TRAIL-induced apoptosis plays an important part in CD4~+ T cell-mediated killing of melanoma. In later studys, we found that fresh melanoma cells are resistant to TRAIL-induced apoptosis and to the treatment of some other chemotherapeutic drugs as well. So that they are very important to study the TRAIL expression on lymphocyte from melanoma patients and to further know the mechanisms of resistance of cancer cells to apoptosis. Aim: To better understand the effect of TRAIL expression on T lymphocytes from melanoma patients on melanoma cellsMethod: Using flow cytometry and FCM to gate on lymphocyte subpopulations and sensitive avidin-biotin detection methods to detect TRAIL expression on blood lymphocytes from normal subjects and melanoma patients by induction of IFN- α 2 and IFN- γ . We generated TRAIL-selected melanoma cells by prolonged exposure to TRAIL in vitro and test the protein levels of caspase-8, caspase-3, caspase-9, p21, p53, p27, Erk 1/2, Akt, p-Erk 112 and p- Akt. Test the proliferative potential in parental and selected cells by MTT assay and cell colony formation in vitro and in vivo.Results: In this study, we show that lymphocyte from melanoma patients express high levels of TRAIL on their surface than those from controls, and that lymphocyte from patients at early stages expressed higher levels of TRAIL after exposure to IFN-α2 and...