OVERVIEW

B7-H3 is an immunomodulatory transmembrane N-linked glycoprotein that is overexpressed in a number of solid tumors including small cell lung cancer, non-small cell lung cancer, breast cancer, and others.1



  • B7-H3 (CD276) is an immune checkpoint member of the B7 and CD28 families.2
  • B7-H3 was initially characterized as a T cell-stimulating protein, although the majority of current studies describe B7-H3 as a T cell inhibitor that promotes tumor aggressiveness and proliferation. This suggests that B7-H3 may be an important immunological target in cancer.3
  • The differential expression of B7-H3 in tumors versus healthy tissues makes targeting of B7-H3 particularly attractive, potentially with limited side effects.3

IMPLICATIONS IN CANCER

  • As detected by immunochemistry technique, over 60% and up to 93% of patient tumor tissues display aberrant expression of B7-H3 in the vast majority of cancer types, while limited expression is seen on normal healthy tissues.2
  • A high expression of B7-H3 in cancer cells correlated with bad prognosis and poor clinical outcome.2
  • The molecular mechanisms by which B7-H3 participates in tumor growth and immune evasion remain elusive; however, the aberrant expression of B7-H3 constitutes a potential biomarker and a promising target for multiple cancer therapeutic approaches.2
  1. Castellanos JR, Purvis IJ, Labak CM, et al. B7-H3 role in the immune landscape of cancer. Am J Clin Exp Immunol. 2017;6(4):66–75.
  2. Picarda E, Ohaegbulam KC, Zang X. Molecular Pathways: Targeting B7-H3 (CD276) for Human Cancer Immunotherapy. Clin Cancer Res. 2016;22(14):3425–3431.
  3. Flem-Karlsen K, et al. B7-H3 in Cancer – Beyond Immune Regulation. Trends in Cancer 2018;4(6):401-404.