Loss of major histocompatibility complex-encoded transporter associated with antigen presentation (TAP) in colorectal cancer.

摘要: Presentation of endogenous antigenic peptides to cytotoxic T lymphocytes (CTLs) is mediated by the major histocompatibility complex (MHC) class I molecules. These derived from cytoplasmic protein pool are transported recently described MHC-encoded transporters (TAP1 and TAP2) into a pre-Golgi region where they take part in assembly MHC Using an affinity-purified polyclonal antibody (AK1.7) for TAP1, we analyzed 81 colorectal carcinomas, 32 adenomas, respective nonneoplastic mucosa. Loss transporter molecule (TAP1) was observed 14% (11 81) either complete (7 11) or focal (4 11), whereas adenomas normal mucosa were always positive. This study adds further information understanding mechanisms related defective presentation molecules tumor cells.