Inflammasome activation is critical to the protective immune response during chemically induced squamous cell carcinoma

Chronic inflammation affects most stages of tumorigenesis, including initiation, promotion, malignant differentiation, invasion and metastasis. Inflammasomes have been described as involved with persistent inflammation and are known to exert both pro and antitumour effects. We evaluated the influence of apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and caspase (CASP)-1 in the antitumor immune response using a multistage model of squamous cell carcinoma (SCC) development. Absence of ASC and CASP-1 resulted in an earlier incidence and increased number of papilloma. Loss of inflammassome function in mice resulted in decreased presence of natural killer (NK), dendritic (DC), CD4+, CD8+ and CD45RB+ T cells in the tumor lesions as well as in lymph nodes (LN) compared with WT mice. Increased percentage of CD4+CD25+Foxp3+ T cells was associated with association with inflammasome loss of function. Moreover, significant differences were also found with neutrophils and macrophage infiltrating the lesions. Myeloperoxidase (MPO), but not elastase (ELA), activity oscillated among the groups during the SCC development. Levels of proinflammatory cytokines IL-1β, IL-18, Tumor Necrosis Factor (TNF)-α and Interferon (IFN)-γ were decreased in the tumor microenvironment in the absence of inflammasome proteins. These observations suggest a link between inflammasome function and SCC tumorigenesis, indicating an important role for inflammasome activation in the control of SCC development.Fil: Gasparoto, Thais Helena. Universidad de São Paulo. Faculdade de Odontologia de Bauru. Departamento de Ciencias Biológicas; BrasilFil: Ervolino de Oliveira, Carine. Universidad de São Paulo. Faculdade de Odontologia de Bauru. Departamento de Ciencias Biológicas; BrasilFil: Thomazini de Freitas, Luisa. Universidad de São Paulo. Faculdade de Odontologia de Bauru. Departamento de Ciencias Biológicas; BrasilFil: Ramos Pinheiro, Claudia. Universidad de São Paulo. Faculdade de Odontologia de Bauru. Departamento de Ciencias Biológicas; BrasilFil: Issa Hori, Juliana. University of São Paulo. Faculdade de Medicina de Ribeirão Preto; BrasilFil: Pompermaier Garlet, Gustavo. Universidad de São Paulo. Faculdade de Odontologia de Bauru. Departamento de Ciencias Biológicas; BrasilFil: Cavassani, Karen Angélica. University Of Michigan; Estados UnidosFil: Schillaci, Roxana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Santana Da Silva, Joao. University of São Paulo. Faculdade de Medicina de Ribeirão Preto; BrasilFil: Simmões Zamboni, Darío. University of São Paulo. Faculdade de Medicina de Ribeirão Preto; BrasilFil: Campanelli, Ana Paula. Universidad de São Paulo. Faculdade de Odontologia de Bauru. Departamento de Ciencias Biológicas; Brasi

Inflammatory events during murine squamous cell carcinoma development

Background: Squamous cell carcinoma (SCC) is one of the most common human cancers worldwide. In SCC, tumour development is accompanied by an immune response that leads to massive tumour infiltration by inflammatory cells, and consequently, local and systemic production of cytokines, chemokines and other mediators. Studies in both humans and animal models indicate that imbalances in these inflammatory mediators are associated with cancer development. Methods: We used a multistage model of SCC to examine the involvement of elastase (ELA), myeloperoxidase (MPO), nitric oxide (NO), cytokines (IL-6, IL-10, IL-13, IL-17, TGF-β and TNF-α), and neutrophils and macrophages in tumour development. ELA and MPO activity and NO, IL-10, IL −17, TNF-α and TGF-β levels were increased in the precancerous microenvironment. Results: ELA and MPO activity and NO, IL-10, IL −17, TNF-α and TGF-β levels were increased in the precancerous microenvironment. Significantly higher levels of IL-6 and lower levels of IL-10 were detected at 4 weeks following 7,12-Dimethylbenz(a)anthracene (DMBA) treatment. Similar levels of IL-13 were detected in the precancerous microenvironment compared with control tissue. We identified significant increases in the number of GR-1+ neutrophils and F4/80+/GR-1- infiltrating cells in tissues at 4 and 8 weeks following treatment and a higher percentage of tumour-associated macrophages (TAM) expressing both GR-1 and F4/80, an activated phenotype, at 16 weeks. We found a significant correlation between levels of IL-10, IL-17, ELA, and activated TAMs and the lesions. Additionally, neutrophil infiltrate was positively correlated with MPO and NO levels in the lesions. Conclusion: Our results indicate an imbalance of inflammatory mediators in precancerous SCC caused by neutrophils and macrophages and culminating in pro-tumour local tissue alterations.FAPESP [2011/03195-1; 2006/01617-8; 2009/14127-7; 2009/03471-9]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Inflammatory events during murine squamous cell carcinoma development

Abstract Background Squamous cell carcinoma (SCC) is one of the most common human cancers worldwide. In SCC, tumour development is accompanied by an immune response that leads to massive tumour infiltration by inflammatory cells, and consequently, local and systemic production of cytokines, chemokines and other mediators. Studies in both humans and animal models indicate that imbalances in these inflammatory mediators are associated with cancer development. Methods We used a multistage model of SCC to examine the involvement of elastase (ELA), myeloperoxidase (MPO), nitric oxide (NO), cytokines (IL-6, IL-10, IL-13, IL-17, TGF-β and TNF-α), and neutrophils and macrophages in tumour development. ELA and MPO activity and NO, IL-10, IL −17, TNF-α and TGF-β levels were increased in the precancerous microenvironment. Results ELA and MPO activity and NO, IL-10, IL −17, TNF-α and TGF-β levels were increased in the precancerous microenvironment. Significantly higher levels of IL-6 and lower levels of IL-10 were detected at 4 weeks following 7,12-Dimethylbenz(a)anthracene (DMBA) treatment. Similar levels of IL-13 were detected in the precancerous microenvironment compared with control tissue. We identified significant increases in the number of GR-1+ neutrophils and F4/80+/GR-1- infiltrating cells in tissues at 4 and 8 weeks following treatment and a higher percentage of tumour-associated macrophages (TAM) expressing both GR-1 and F4/80, an activated phenotype, at 16 weeks. We found a significant correlation between levels of IL-10, IL-17, ELA, and activated TAMs and the lesions. Additionally, neutrophil infiltrate was positively correlated with MPO and NO levels in the lesions. Conclusion Our results indicate an imbalance of inflammatory mediators in precancerous SCC caused by neutrophils and macrophages and culminating in pro-tumour local tissue alterations.</p

Characterization of SCC lesions in the absence of inflammasome after 12 weeks.

<p>(A) The absolute number and phenotype of leukocytes in the tumor lesions were determined by flow cytometry. (B) Flow cytometry analyses of CD25⁺Foxp3⁺, CD45RA⁺, CD45RB⁺ and CD28⁻CD62L⁻ expression on CD4 e CD8 T cells. (C) Myeloperoxidase (MPO) and elastase (ELA) activity in tumor microenvironment. (D) Cytokines profile in tumor microenvironment at 12 weeks after SCC induction. Values are mean ± SEM; *<i>p</i>≤0.05, *** <i>p</i>≤0.001 compared with WT mice.</p

Absence of inflammasome molecules induced an increase of papilloma incidence and volume during SCC development.

<p>ASC-KO (gray square), CASP-1-KO (black square) and WT (white square) mice were treated according to a chemical carcinogenic protocol using DMBA and PMA for 20 weeks. (A) The incidence, average number and volume of papillomas were determined. Data shown represent mean ± SEM; *<i>p</i>≤0.05, ** <i>p</i>≤0.01, *** <i>p</i>≤0.001 compared with WT mice. Representative data are show from at least three independent experiments. (B) Representative haematoxylin and eosin staining of skin section from 12, 16 and 20 weeks after SCC induction. Scale bars represent 50 uM.</p

Characterization of SCC lesions in the absence of inflammasome after 20 weeks.

<p>(A) The absolute number and phenotype of leukocytes in the tumor lesions were determined by flow cytometry. (B) Flow cytometry analyses of CD25⁺Foxp3⁺, CD45RA⁺, CD45RB⁺ and CD28⁻CD62L⁻ expression on CD4 e CD8 T cells. (C) Myeloperoxidase (MPO) and elastase (ELA) activity in tumor microenvironment. (D) Cytokines profile in tumor microenvironment at 20 weeks after SCC induction. Values are mean ± SEM; *<i>p</i>≤0.05, *** <i>p</i>≤0.001 compared with WT mice.</p