Volker Teichgräber1, Carmen Monasterio2, Krishna Chaitanya3, Regina Boger2, Katrin Gordon2, Thomas Dieterle4, Dirk Jäger2, Stefan Bauer2. 1. National Center for Tumor Diseases, Department of Medical Oncology, University Hospital Heidelberg, Heidelberg, Germany. Electronic address: volker.teichgraeber@nct-heidelberg.de. 2. National Center for Tumor Diseases, Department of Medical Oncology, University Hospital Heidelberg, Heidelberg, Germany. 3. Division of Oncology, University Hospital Zurich, Zurich, Switzerland. 4. Kantonsspital Liestal, Department of Medicine and Clinical Research, University Hospital Basel, Liestal, Switzerland.
Abstract
PURPOSE: Solid tumors modulate their environment to keep non-malignant stromal cells in a tumor-promoting state. The main cells in the stroma of epithelial derived tumors are cancer associated fibroblasts (CAF) that are critical to tumorigenesis and angiogenesis. CAFs also supply the tumor cells with growth factors and extracellular matrix (ECM) degrading enzymes. They are thus essential for tumor initiation as well as tumor progression and metastasis, suggesting that they represent an ideal cellular target of an integrative tumor therapy. Fibroblast activation protein (FAP) is a well-defined marker, expressed at high levels on the cell surface of CAFs. FAP, a constitutively active serine peptidase with both dipeptidyl peptidase IV (DPP IV) and collagenase/gelatinase activity, promotes malignant and invasive behavior of epithelial cancers. High stromal expression levels of FAP correlate with poor prognosis. FAP is difficult to detect in non-diseased adult tissue, but it is generally expressed at sites of tissue remodeling. MATERIALS AND METHODS: In our experiments, we aimed for a reduction of the pro-tumorigenic activities of CAFs by depleting FAP from fibroblasts growing in a composite environment with epithelial tumor cells. RESULTS: FAP depletion was achieved by two therapeutically relevant approaches: a novel internalizing anti-FAP IgG1 antibody and FAP gene knock-down by siRNA delivery. The antibody effectively removed FAP from the cell surface and was capable of reversing the FAP mediated migratory and invasive capacity. FAP RNA interference was equally effective when compared to the antibody. CONCLUSIONS: Thus, targeting FAP on CAF suppresses pro-tumorigenic activities and may result in a clinically effective reduction of tumor progression and dissemination.
PURPOSE: Solid tumors modulate their environment to keep non-malignant stromal cells in a tumor-promoting state. The main cells in the stroma of epithelial derived tumors are cancer associated fibroblasts (CAF) that are critical to tumorigenesis and angiogenesis. CAFs also supply the tumor cells with growth factors and extracellular matrix (ECM) degrading enzymes. They are thus essential for tumor initiation as well as tumor progression and metastasis, suggesting that they represent an ideal cellular target of an integrative tumor therapy. Fibroblast activation protein (FAP) is a well-defined marker, expressed at high levels on the cell surface of CAFs. FAP, a constitutively active serine peptidase with both dipeptidyl peptidase IV (DPP IV) and collagenase/gelatinase activity, promotes malignant and invasive behavior of epithelial cancers. High stromal expression levels of FAP correlate with poor prognosis. FAP is difficult to detect in non-diseased adult tissue, but it is generally expressed at sites of tissue remodeling. MATERIALS AND METHODS: In our experiments, we aimed for a reduction of the pro-tumorigenic activities of CAFs by depleting FAP from fibroblasts growing in a composite environment with epithelial tumor cells. RESULTS:FAP depletion was achieved by two therapeutically relevant approaches: a novel internalizing anti-FAP IgG1 antibody and FAP gene knock-down by siRNA delivery. The antibody effectively removed FAP from the cell surface and was capable of reversing the FAP mediated migratory and invasive capacity. FAP RNA interference was equally effective when compared to the antibody. CONCLUSIONS: Thus, targeting FAP on CAF suppresses pro-tumorigenic activities and may result in a clinically effective reduction of tumor progression and dissemination.
Authors: Marika Musielak; Oliwia Piwocka; Katarzyna Kulcenty; Karolina Ampuła; Beata Adamczyk; Igor Piotrowski; Magdalena Fundowicz; Marta Kruszyna-Mochalska; Wiktoria M Suchorska; Julian Malicki Journal: Am J Cancer Res Date: 2022-09-15 Impact factor: 5.942
Authors: Muzafar A Macha; Nissar A Wani; Rais A Ganai; Ajaz A Bhat; Abid Hamid; Sheema Hashem; Mohammad Haris; Sham S Chauhan; Mohammad A Zargar; Surinder K Batra Journal: Adv Exp Med Biol Date: 2020 Impact factor: 2.622