Antibody-Mediated Inhibition of Cathepsin S Blocks Colorectal Tumor Invasion and Angiogenesis

Roberta E. Burden, Julie A. Gormley, Thomas J. Jaquin, Donna Small, Derek J. Quinn, Shauna Hegarty, Claire Ward, Brian Walker, James A. Johnston, Shane A. Olwill, Christopher J. Scott

Research output: Contribution to journalArticlepeer-review

89 Citations (Scopus)


Purpose: Cathepsin S is a cysteine protease that promotes the invasion of tumor and endothelial cells during cancer progression. Here we investigated the potential to target cathepsin S using an antagonistic antibody, Fsn0503, to block these tumorigenic effects.
Experimental Design: A panel of monoclonal antibodies was raised to human cathepsin S. The effects of a selected antibody were subsequently determined using invasion and proteolysis assays. Endothelial cell tube formation and aorta sprouting assays were done to examine antiangiogenic effects. In vivo effects were also evaluated using HCT116 xenograft studies.
Results: A selected cathepsin S antibody, Fsn0503, significantly blocked invasion of a range of tumor cell lines, most significantly HCT116 colorectal carcinoma cells, through inhibition of extracellular cathepsin S–mediated proteolysis. We subsequently found enhanced expression of cathepsin S in colorectal adenocarcinoma biopsies when compared with normal colon tissue. Moreover, Fsn0503 blocked endothelial cell capillary tube formation and aortic microvascular sprouting. We further showed that administration of Fsn0503 resulted in inhibition of tumor growth and neovascularization of HCT116 xenograft tumors.
Conclusions: These results show that blocking the invasive and proangiogenic effects of cathepsin S with antibody inhibitors may have therapeutic utility upon further preclinical and clinical evaluation.
Original languageEnglish
Pages (from-to)6042-6051
Number of pages10
JournalClinical Cancer Research
Issue number19
Early online date29 Sept 2009
Publication statusPublished - 01 Oct 2009

ASJC Scopus subject areas

  • Cancer Research
  • Oncology


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