High-dimensional Cytometry (ExCYT) and Mass Spectrometry of Myeloid Infiltrate in Clinically Localized Clear Cell Renal Cell Carcinoma Identifies Novel Potential Myeloid Targets for Immunotherapy

Mol Cell Proteomics. 2020 Nov;19(11):1850-1859. doi: 10.1074/mcp.RA120.002049. Epub 2020 Jul 31.

Abstract

Renal Cell Carcinoma (RCC) is one of the most commonly diagnosed cancers worldwide with research efforts dramatically improving understanding of the biology of the disease. To investigate the role of the immune system in treatment-naïve clear cell Renal Cell Carcinoma (ccRCC), we interrogated the immune infiltrate in patient-matched ccRCC tumor samples, benign normal adjacent tissue (NAT) and peripheral blood mononuclear cells (PBMCs isolated from whole blood, focusing our attention on the myeloid cell infiltrate. Using flow cytometric, MS, and ExCYT analysis, we discovered unique myeloid populations in PBMCs across patient samples. Furthermore, normal adjacent tissues and ccRCC tissues contained numerous myeloid populations with a unique signature for both tissues. Enrichment of the immune cell (CD45+) fraction and subsequent gene expression analysis revealed a number of myeloid-related genes that were differentially expressed. These data provide evidence, for the first time, of an immunosuppressive and pro-tumorigenic role of myeloid cells in early, clinically localized ccRCC. The identification of a number of immune proteins for therapeutic targeting provides a rationale for investigation into the potential efficacy of earlier intervention with single-agent or combination immunotherapy for ccRCC.

Keywords: ExCYT; clear cell renal cell carcinoma; clinical proteomics; immunology; immunotherapy; kidney cancer; macrophages; mass spectrometry; monocytes; peripheral blood mononuclear cells; tumor microenvironment.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biomarkers, Tumor / analysis
  • Biomarkers, Tumor / blood*
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / immunology
  • Carcinoma, Renal Cell / genetics
  • Carcinoma, Renal Cell / immunology
  • Carcinoma, Renal Cell / metabolism*
  • Flow Cytometry
  • Gene Expression Regulation, Neoplastic / immunology
  • Genomics
  • Humans
  • Immunotherapy / methods*
  • Kidney Neoplasms / genetics
  • Kidney Neoplasms / immunology
  • Kidney Neoplasms / metabolism*
  • Leukocyte Common Antigens / blood*
  • Leukocytes, Mononuclear / cytology
  • Leukocytes, Mononuclear / metabolism*
  • Mass Spectrometry
  • Prognosis
  • Signal Transduction
  • Tandem Mass Spectrometry
  • Tumor Microenvironment / immunology*

Substances

  • Biomarkers, Tumor
  • Leukocyte Common Antigens
  • PTPRC protein, human