Costimulatory B7-H1 in Renal Cell Carcinoma Patients: Indicator of Tumor Aggressiveness and Potential Therapeutic Target

• Published in: Proceedings of the National Academy of Sciences - PNAS 2004-12, Vol.101 (49), p.17174-17179
• Main Authors: Thompson, R. Houston, Gillett, Michael D., Cheville, John C., Lohse, Christine M., Dong, Haidong, Webster, W. Scott, Krejci, Kent G., Lobo, John R., Sengupta, Shomik, Chen, Lieping, Zincke, Horst, Blute, Michael L., Strome, Scott E., Leibovich, Bradley C., Kwon, Eugene D., Allison, James P.
• Format: Article
• Language: English
• Subjects: Antigens, CD; B7-1 Antigen - analysis; B7-H1 Antigen; Biological Sciences; Cancer; Carcinoma, Renal Cell - chemistry; Carcinoma, Renal Cell - mortality; Carcinoma, Renal Cell - pathology; Follow-Up Studies; Glycoproteins; Histology; Humans; Immunity; Immunohistochemistry; Immunology; Immunotherapy; Kidneys; Lymphocytes; Lymphocytes, Tumor-Infiltrating - chemistry; Membrane Glycoproteins - analysis; Necrosis; Neoplasm Proteins - analysis; Odds Ratio; Pathology; Peptides - analysis; Prognosis; Renal cell carcinoma; Survival Analysis; T lymphocytes; Tumors
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0406351101

Expression of B7-H1, a costimulating glycoprotein in the B7 family, is normally restricted to macrophage-lineage cells, providing a potential costimulatory signal source for regulation of T cell activation. In contrast, aberrant expression of B7-H1 by tumor cells has been implicated in impairment of T cell function and survival, resulting in defective host antitumoral immunity. The relationship between tumor-associated B7-H1 and clinical cancer progression is unknown. Herein, we report B7-H1 expression by both renal cell carcinoma (RCC) tumors of the kidney and RCC tumor-infiltrating lymphocytes. In addition, our analysis of 196 clinical specimens reveals that patients harboring high intratumoral expression levels of B7-H1, contributed by tumor cells alone, lymphocytes alone, or tumor and/or lymphocytes combined, exhibit aggressive tumors and are at markedly increased risk of death from RCC. In fact, patients with high tumor and/or lymphocyte B7-H1 levels are 4.5 times more likely to die from their cancer than patients exhibiting low levels of B7-H1 expression (risk ratio 4.53; 95% confidence interval 1.94-10.56; P < 0.001.) Thus, our study suggests a previously undescribed mechanism whereby RCC may impair host immunity to foster tumor progression. B7-H1 may prove useful as a prognostic variable for RCC patients both pre- and posttreatment. In addition, B7-H1 may represent a promising target to facilitate more favorable responses in patients who require immunotherapy for treatment of advanced RCC.