HLA Class I Expression, Tumor Escape and Cancer Progression

E-ISSN： 1875-6301|4|2|105-110

ISSN： 1573-3947

Source： Current Cancer Therapy Reviews, Vol.4, Iss.2, 2008-05, pp. : 105-110

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

The progress in genomics and proteomics resulted in increasing number of tumor-associated antigens (TAA) being discovered as cancer biomarkers and targets for immunotherapy. The key role played by HLA class I antigens in immune reactivity against malignant and virally infected cells via binding to the peptides of TAA and subsequent presentation to cytotoxic T-lymphocytes stimulates interest in the characterization of their expression in tumor cells. Various types of HLA class I alterations with different underlying molecular mechanisms are found in different malignancies. Loss or downregulation of tumor HLA class I antigen expression represents one of the main mechanisms used by cancer cells to evade immunosurveillance since it limits the ability of cytotoxic T-cell to eliminate these cells and reduces the clinical efficacy of T-cell-based cancer therapy. As a result of the immune selection, HLA class I negative variants escape and lead to tumor growth and metastatic colonization. Altered HLA class I expression on malignant cells frequently correlates with poor survival, disease progression and limited response to T-cell-based therapy. Early cancer detection and treatment require more effective cancer biomarkers, or molecular signatures, for diagnosis, prognosis, and therapeutic efficacy. Analysis of the tumor expression of HLA class I antigens as biomarkers of cancer development might help to choose an appropriate treatment protocol and monitor clinical response to cancer immunotherapy.