Inhibition of hypoxia-inducible factors limits tumor progression in a mouse model of colorectal cancer

• Published in: Carcinogenesis (New York) 2014-05, Vol.35 (5), p.1067-1077
• Main Authors: Shay, Jessica E.S., Imtiyaz, Hongxia Z., Sivanand, Sharanya, Durham, Amy C., Skuli, Nicolas, Hsu, Sarah, Mucaj, Vera, Eisinger-Mathason, T.S.Karin, Krock, Bryan L., Giannoukos, Dionysios N., Simon, M.Celeste
• Format: Article
• Language: English
• Subjects: Acriflavine - administration & dosage; Acriflavine - pharmacology; Animals; Antineoplastic Agents - administration & dosage; Antineoplastic Agents - pharmacology; Aryl Hydrocarbon Receptor Nuclear Translocator - genetics; Aryl Hydrocarbon Receptor Nuclear Translocator - metabolism; Cell Line, Tumor; Cell Proliferation - drug effects; Colorectal Neoplasms - genetics; Colorectal Neoplasms - metabolism; Colorectal Neoplasms - pathology; Disease Models, Animal; Disease Progression; Female; Humans; Hypoxia-Inducible Factor 1, alpha Subunit - genetics; Hypoxia-Inducible Factor 1, alpha Subunit - metabolism; Macrophages - drug effects; Macrophages - metabolism; Macrophages - pathology; Mice; Neovascularization, Pathologic - drug therapy; Neovascularization, Pathologic - genetics; Original Manuscript; Signal Transduction - drug effects; Transcription, Genetic - drug effects; Tumor Burden - drug effects; Tumor Burden - genetics; Xenograft Model Antitumor Assays
• ISSN: 0143-3334; 1460-2180
• DOI: 10.1093/carcin/bgu004

Summary Acriflavine, a known HIF inhibitor, limits murine colorectal cancer progression through HIF-specific effects on both colonic epithelial cells and recruited macrophages. Hypoxia-inducible factors (HIFs) accumulate in both neoplastic and inflammatory cells within the tumor microenvironment and impact the progression of a variety of diseases, including colorectal cancer. Pharmacological HIF inhibition represents a novel therapeutic strategy for cancer treatment. We show here that acriflavine (ACF), a naturally occurring compound known to repress HIF transcriptional activity, halts the progression of an autochthonous model of established colitis-associated colon cancer (CAC) in immunocompetent mice. ACF treatment resulted in decreased tumor number, size and advancement (based on histopathological scoring) of CAC. Moreover, ACF treatment corresponded with decreased macrophage infiltration and vascularity in colorectal tumors. Importantly, ACF treatment inhibited the hypoxic induction of M-CSFR, as well as the expression of the angiogenic factor (vascular endothelial growth factor), a canonical HIF target, with little to no impact on the Nuclear factor-kappa B pathway in bone marrow-derived macrophages. These effects probably explain the observed in vivo phenotypes. Finally, an allograft tumor model further confirmed that ACF treatment inhibits tumor growth through HIF-dependent mechanisms. These results suggest pharmacological HIF inhibition in multiple cell types, including epithelial and innate immune cells, significantly limits tumor growth and progression.