Chronic obstructive pulmonary disease (COPD) is now the fourth-leading cause of death worldwide and its prevalence is increasing. The progressive decline of lung function and airway remodelling are a consequence of chronic inflammatory responses. It was recently postulated the involvement of the inflammasome in COPD, although the underlying mechanism/s still need to be elucidated. Therefore, we isolated peripheral blood mononuclear cells (PBMCs) from exacerbated/unstable COPD patients. The stimulation of PBMCs with an AIM2 inflammasome activator, Poly dA:dT, led to IL-1α, but not IL-1β, release. The release of this cytokine was caspase-1- and caspase-4-dependent and correlated to higher levels of 8-OH-dG in COPD compared to non-smoker and smoker-derived PBMCs. Interestingly, AIM2-depedent IL-1α release was responsible for higher TGF-β levels, crucial mediator during pro-fibrotic processes associated to COPD progression. In conclusion, our data highlight the involvement of AIM2/caspase-1/caspase-4 in IL-1α-induced TGF-β release in unstable COPD-derived PBMCs, opening new therapeutic perspectives for unstable COPD patients.

Idiopathic pulmonary fibrosis (IPF) is a chronic fibro-proliferative disease characterized by poor prognosis, with a mean survival of ~2–3 years after definite diagnosis. The cause of IPF is still unknown but it is a heterogeneous condition in which the aberrant deposition of extracellular matrix leads to extensive lung remodeling. This remodeling is a consequence of inflammatory responses, but the mechanisms involved are poorly understood. In this study, we first analyzed a bleomycin-induced mouse model, which showed that higher expression of IL-1β, but not IL-18, was correlated to pulmonary cell infiltration and fibrosis. Then, we found that peripheral blood mononuclear cells (PBMCs) from IPF patients released IL-1α and IL-18 in a NLRP3- and calpain-independent manner after LPS ± ATP stimulation. Instead, the activation of the absent in melanoma 2 (AIM2) inflammasome induced the release of IL-1α in a caspase-1-/caspase-8-independent manner; whereas IL-18 release was caspase-1 dependent. These effects correlated with the release of the pro-fibrotic TGF-β, which was induced by AIM2 activation in a caspase-1- and TLR4-independent manner, but dependent on IL-1α. In this context, the activation of AIM2 induced the release of caspase-4 from IPF-derived PBMCs, which correlated with the mRNA levels of this caspase that was higher in IPF than in healthy PBMCs. In conclusion, our findings identify a novel molecular mechanism whereby the activation of AIM2 could lead to the activation of the non-canonical inflammasome (caspase-4 dependent) that induces the release of IL-1α responsible for the release of TGF-β from PBMCs of IPF patients.

Late diagnosis limits therapeutic options and survival rate of non-small cell lung cancer (NSCLC) patients. Therefore the identification of biomarkers represents an emerging medical need.A highly sensitive and specific test was developed to identify/quantify a novel/selective diagnostic biomarker for NSCLC patients, caspase-4. This test was validated by using i) plasma from 125 NSCLC patients and 79 healthy (non-pathological) subjects, ii) plasma from 139 smokers and iii) from 70 chronic-obstructive pulmonary disease (COPD) patients. Caspase-4 quantification was also assessed in the lung tumor mass of 98 paired NSCLC patients compared to 10 non-tumor lung tissues (i.e. tuberculosis).Circulating caspase-4 was detected in both healthy and NSCLC patients; however at different range values: 2.603–3.372 ng/ml for NSCLC patients (95% CI) compared to 0.3994-0.6219 ng/ml for healthy subjects (95% CI). The sensitivity of the test ranged from 97.07% to 100%; the specificity was 88.1% with a positive predictive value of 92.54%, accuracy of 95.19% and AUC of 0.971. Smokers (95% CI, 0.3947–0.6197 ng/ml) and COPD patients (95% CI, 1.703–2.995 ng/ml) showed intermediate values of circulating caspase-4. Tissue levels of caspase-4 in the tumor mass showed that 72 (72.7%) out of 99 patients were positive. More importantly, higher levels (cut-off value = 0.307 ng/ml) of caspase-4 in the tumor mass were associated to reduced overall survival (median 0.92 years) compared to NSCLC patients with lower levels (median 3.02 years).We report for the first time caspase-4 as a novel diagnostic and prognostic biomarker, opening new therapeutic perspectives for NSCLC patients.

Purpose: Osteopontin is a secreted cytokine that binds to the cell surface CD44v6 receptor.We studied osteopontin and CD44v6 expression in laryngeal squamous cell carcinomas and correlated osteopontin expression levels with clinicopathologic tumor features. Experimental Design: We used immunohistochemistry, immunoblotting, and reverse transcription-PCR to study osteopontin expression in 58 laryngeal squamous cell carcinomas. Cultured squamous carcinoma cells were treated with exogenous osteopontin or with RNA interference to knockdown osteopontin expression. Results: Osteopontin expression was higher in all the invasive carcinomas than in patientmatched normal mucosa. Its expression levels were significantly correlated with tumor stage and grade and with the presence of lymph node and distant metastases. Osteopontin positivity was negatively correlated with overall survival (P = 0.03). Osteopontin expression was paralleled by intense cell surface reactivity for CD44v6. Treatment of squamous carcinoma cells with recombinant osteopontin sharply increased proliferation and Matrigel invasion in comparison with the untreated cells parallel to activation of the mitogen-activated protein kinase/extracellular signalregulated kinase kinase/mitogen-activated protein kinase signaling cascade. Osteopontin knockdown by RNA interference, anti-CD44 antibodies, and mitogen-activated protein kinase/ extracellular signal-regulated kinase kinase inhibition prevented these effects. Conclusions: These results identify osteopontin as a marker and a potential therapeutic target in cases of aggressive laryngeal squamous cell carcinomas.Head and neck squamous cell carcinoma (HNSCC) is the sixth most frequent cancer. Laryngeal squamous cell carcinoma (LSCC) is the most common HNSCC (1 -3). Notwithstanding primary prevention, screening, surgical treatment, and radiotherapy, the long-term survival rate of LSCC patients has remained substantially unchanged in the last two decades (4, 5). Stage and histologic grade are prognostic factors in LSCC but do not always distinguish between high-risk and low-risk patients (1-5). Various biological prognostic markers have been identified for LSCC and other HNSCC types: mutation in the p53 tumor suppressor gene (6), amplification of cyclin D1 (7, 8), overexpression of the epidermal growth factor receptor (9) and vascular endothelial growth factor (10), and reduced expression of the CIP/KIP cell cycle inhibitory proteins (11). However, little is known about the molecular mechanisms that govern the establishment and maintenance of the LSCC neoplastic phenotype.Osteopontin, also known as secreted phosphoprotein 1, is a highly acidic calcium-binding glycosylated phosphoprotein. It is a cytokine (early T lymphocyte antigen-1 or interleukin-28) that regulates T helper cell-1 function (12, 13). In addition, osteopontin binds to the cell surface receptors a v -or h 1 -containing integrins and CD44 (14, 15), thereby supporting chemotaxis, attachment, and migration of many epithelial cell types (16,17)...

Loss of ERbeta expression, high PCNA expression and aneuploidy, characterized a subgroup of OGCT with a worse outcome. The identification of a high-risk subclass of OGCT may be of primary importance in addressing appropriate therapeutic strategies, offering the chance to prevent relapses and metastases by using adjunctive, specifically targetted, more aggressive therapies.