npj Precision Oncology (Nov 2022)

Integrative molecular analyses define correlates of high B7-H3 expression in metastatic castrate-resistant prostate cancer

  • Xiaolei Shi,
  • Abderrahman Day,
  • Hannah E. Bergom,
  • Sydney Tape,
  • Sylvan C. Baca,
  • Zoi E. Sychev,
  • Gabrianne Larson,
  • Asha Bozicevich,
  • Justin M. Drake,
  • Nicholas Zorko,
  • Jinhua Wang,
  • Charles J. Ryan,
  • Emmanuel S. Antonarakis,
  • Justin Hwang

DOI
https://doi.org/10.1038/s41698-022-00323-2
Journal volume & issue
Vol. 6, no. 1
pp. 1 – 6

Abstract

Read online

Abstract B7-H3 (CD276) is an immune checkpoint overexpressed in prostate cancer with minimal expression in normal tissues and associated with poor prognosis, making it an excellent therapy target. We interrogated B7-H3 expression and its regulation in metastatic castration-resistant prostate cancer (mCRPC). We found greater expression of B7-H3 transcript relative to other immunotherapy targets (CTLA-4, PD-L1/2), including in tumors that lacked expression of prostate-specific membrane antigen (PSMA). Enzalutamide-resistant mCRPC cells demonstrated increased amounts of B7-H3, and this was associated with resistance signaling pathways. Using a machine-learning algorithm, the gene network of B7-H3 was strongly correlated with androgen receptor (AR) and AR co-factor (HOXB13, FOXA1) networks. In mCRPC samples, the B7-H3 promoter and distal enhancer regions exhibited enhanced transcriptional activity and were directly bound by AR and its co-factors. Altogether, our study characterizes molecular profiles and epigenetic regulation of B7-H3-expressing mCRPC tumors, which informs optimal precision-oncology approaches for mCRPC patients.