Bacillus Calmette Guerin induces fibroblast activation both directly and through macrophages in a mouse bladder cancer model

• Published in: PloS one Vol. 5; no. 10; p. e13571
• Main Authors: Lodillinsky, Catalina, Langle, Yanina, Guionet, Ariel, Góngora, Adrián, Baldi, Alberto, Sandes, Eduardo O, Casabé, Alberto, Eiján, Ana María
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 22.10.2010; Public Library of Science (PLoS)
• Subjects: 1-Phosphatidylinositol 3-kinase; Actin; Analysis; Animal models; Animals; Apoptosis; Bacillus; Bacillus Calmette-Guerin vaccine; BCG; BCG Vaccine - immunology; Biological activity; Bladder; Bladder cancer; Cancer; Cancer therapies; Cell activation; Cell adhesion & migration; Cell Biology/Extra-Cellular Matrix; Cell cycle; Cell Differentiation; Cell Proliferation; Collagen; Combined treatment; Cytokines; Disease Models, Animal; Extracellular matrix; Fibroblast growth factor 2; Fibroblast Growth Factor 2 - physiology; Fibroblast growth factors; Fibroblasts; Fibroblasts - cytology; Fibroblasts - immunology; Fibrosis; Growth factors; Immunotherapy; In vivo methods and tests; Inoculation; Invasiveness; Laboratories; Macrophages; Macrophages, Peritoneal - immunology; MAP kinase; Mice; Muscle proteins; NG-Nitroarginine methyl ester; NIH 3T3 Cells; Nitric oxide; Nitric Oxide - antagonists & inhibitors; Oncology; Oncology/Bladder Cancer and Urothelial Neoplasias of the Urinary Tract; Oral administration; Peritoneum; Rodents; Signaling; Smooth muscle; Tumors; Urinary bladder; Urinary Bladder Neoplasms - immunology; Urinary Bladder Neoplasms - pathology; Urology/Bladder Cancer and Urothelial Neoplasias of the Urinary Tract; Wound care; Wound healing; Argentina
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0013571

Bacillus Calmette-Guerin (BCG) is the most effective treatment for non-muscle invasive bladder cancer. However, a failure in the initial response or relapse within the first five years of treatment has been observed in 20% of patients. We have previously observed that in vivo administration of an inhibitor of nitric oxide improved the response to BCG of bladder tumor bearing mice. It was described that this effect was due to a replacement of tumor tissue by collagen depots. The aim of the present work was to clarify the mechanism involved in this process. We demonstrated that BCG induces NIH-3T3 fibroblast proliferation by activating the MAPK and PI3K signaling pathways and also differentiation determined by alpha-smooth muscle actin (alpha-SMA) expression. In vivo, intratumoral inoculation of BCG also increased alpha-SMA and collagen expression. Oral administration of L-NAME enhanced the pro-fibrotic effect of BCG. Peritoneal macrophages obtained from MB49 tumor-bearing mice treated in vivo with combined treatment of BCG with L-NAME also enhanced fibroblast proliferation. We observed that FGF-2 is one of the factors released by BCG-activated macrophages that is able to induce fibroblast proliferation. The involvement of FGF-2 was evidenced using an anti-FGF2 antibody. At the same time, this macrophage population improved wound healing rate in normal mice and FGF-2 expression was also increased in these wounds. Our findings suggest that fibroblasts are targeted by BCG both directly and through activated macrophages in an immunotherapy context of a bladder murine model. We also described, for the first time, that FGF-2 is involved in a dialog between fibroblasts and macrophages induced after BCG treatment. The fact that L-NAME administration improves the BCG effect on fibroblasts, NO inhibition, might represent a new approach to add to the conventional BCG therapy.