Citation: Chagas JR, Visniauskas B, Gomes GN and Bueno V. Evaluation of Myeloid-derived Suppressor Cells and Components of Renin Angiotensin System in Urethane-induced Lung Cancer. J Immun Res. 2015;2(2): 1018. J Immun Res - Volume 2 Issue 2 - 2015 Submit your Manuscript | www.austinpublishinggroup.com Bueno et al. © All rights are reserved Journal of Immune Research Open Access Abstract Urethane-induced lung cancer has been associated with an imbalance in the effector/suppression immune response since interferon-gamma production is increased along with elevated percentages of myeloid-derived suppressor cells. The goal in cancer therapy is to prevent the immunosuppressive effects caused by tumor and thus lead to the development of effective immune response. The depletion of myeloid-derived suppressor cells in experimental models causes less tumor burden and improves the immune response but doesn´t provide cure. As cancer is a complex and multifactorial disease the treatment also should be based on multiple targets. A recently described target is the renin angiotensin system and its components (i.e. bradikynin receptors, angiotensin-converting enzyme) as they may play a role in cancer development. Therefore, our aim was to investigate the percentage of myeloid-derived suppressor cells at the tumor site and the possible correlation with bradikynin receptors and angiotensin-converting enzyme expressions in mice submitted to Urethane-induced lung cancer. BALB/c mice were either injected with myeloid-derived suppressor cells, Urethane or only followed for 120 days (control). Lung, spleen, and blood were phenotyped for myeloid-derived suppressor cells and lung tissue was evaluated for the expression of renin angiotensin system components. In tumor-bearing mice it was observed a signiicant increase at the percentage of myeloid-derived suppressor cells in the spleen along with angiotensin- converting enzyme increased gene and decreased protein expressions in lung. Urethane administration was crucial to lung tumor development, to the increase of peripheral myeloid-derived suppressor cells and to the changes observed in angiotensin-converting enzyme (ACE). In conclusion, tumor microenvironment seems to modulate myeloid-derived suppressor cells expansion and ACE gene and protein expressions. Myeloid- derived suppressor cells and renin angiotensin system components could be potential targets for cancer diagnostics and therapy. Keywords: Lung cancer; Urethane; Myeloid-derived suppressor cells; Angiotensin-converting enzyme; Bradykinin It has been shown that one of the mechanisms responsible for tumor growth is the increased generation of MDSC in bone marrow followed by their migration to blood and tumor site [3]. hese cells act suppressing the immune system through the secretion of factors such as arginase-1 and TGF-β [reviewed in [4, 5]. Another possible role played by tumor cells and/or MDSC is the interference with hematopoiesis [3]. he increase of myelopoiesis can lead to the inhibition in the complete maturation of myeloid cells and thus to the decrease in the number of inlammatory macrophages and elevation in the number of suppressive immature myeloid cells [6]. In agreement, we found an increased percentage of MDSC in bone marrow of mice induced to lung cancer by Urethane administration [2]. Although MDSCs depletion causes less tumor burden and Introduction Our group has shown previously that Urethane-induced lung cancer leads to an increase in the percentage of myeloid-derived suppressor cells (MDSC) in spleen and lung along with transforming growth factor-beta (TGF-β) expression by tumor cells. In addition, Foxp3 + cells were elevated in lung tissue of Urethane-injected mice [1, 2]. hese indings suggest a suppressive status ater lung cancer induced by Urethane. On the other hand, there was an increase of toll like receptor 4 (TLR4) expressions in lung tissue and interferon- gamma (IFN-γ) production ex-vivo by splenocytes suggesting immune response against tumor [1, 2]. We hypothesized that there is an imbalance of efector immune response versus suppression/ tolerance culminating with cancer development. Special Article-Cancer Immunology Evaluation of Myeloid-derived Suppressor Cells and Components of Renin Angiotensin System in Urethane- induced Lung Cancer Jair Ribeiro Chagas 1,2 , Bruna Visniauskas 1 , Guiomar Nascimento Gomes 3 and Valquiria Bueno 4 * 1 Department of Psychobiology, UNIFESP Federal University of São Paulo, Brazil 2 Department of Biosciences, UNIFESP Federal University of São Paulo, Brazil 3 Department of Physiology, UNIFESP Federal University of São Paulo, Brazil 4 Department of Microbiology, Immunology and Parasitology, UNIFESP Federal University of São Paulo, Brazil *Corresponding author: Valquiria Bueno, Department of Microbiology Immunology and Parasitology, UNIFESP Federal University of São Paulo, Brazil, Tel: 55 11 989622943; Email: valquiriabueno@hotmail.com Received: February 19, 2015; Accepted: March 06, 2015; Published: March 09, 2015