Ernesto Pozzi

Malignant Pleural Mesothelioma (MPM) is an aggressive tumor arising from mesothelial cells lining the pleural cavities characterized by resistance to standard therapies. Most of the molecular steps responsible for pleural transformation remain unclear; however, several growth factor signaling cascades are known to be altered during MPM onset and progression. Transducers of these pathways, such as PIK3CA-mTOR-AKT, MAPK, and ezrin/radixin/moesin (ERM) could therefore be exploited as possible targets for pharmacological intervention. This study aimed to identify ‘druggable’ pathways in MPM and to formulate a targeted approach based on the use of commercially available molecules, such as the multikinase inhibitor sorafenib and the mTOR inhibitor everolimus. We planned a triple approach based on: i) analysis of immunophenotypes and mutational profiles in a cohort of thoracoscopic MPM samples, ii) in vitro pharmacological assays, ii) in vivo therapeutic approaches on MPM xenografts. No mutations were found in ‘hot spot’ regions of the mTOR upstream genes (e.g. EGFR, KRAS and PIK3CA). Phosphorylated mTOR and ERM were specifically overexpressed in the analyzed MPM samples. Sorafenib and everolimus combination was effective in mTOR and ERM blockade; exerted synergistic effects on the inhibition of MPM cell proliferation; triggered ROS production and consequent AMPK-p38 mediated-apoptosis. The antitumor activity was displayed when orally administered to MPM-bearing NOD/SCID mice. ERM and mTOR pathways are activated in MPM and ‘druggable’ by a combination of sorafenib and everolimus. Combination therapy is a promising therapeutic strategy against MPM.

E18084 Background: Until few years ago, the standard first-line CT for NSCLC was based on a platinum-containing doublets, despite of the histological subtyping. This aspect is now becoming relevant in view of a treatment decision process based on the differential activity of new drugs. In this study, we have focused on the impact of histology in pts with advanced-stage NSCLC treated since 2005, at our Institution, outside clinical trials, by a multidisciplinary team, with first-line, standard platinum-based regimens. Methods: We retrospectively evaluated 261 pts, with stage IIIB-IV NSCLC: 164 non-squamous subtype (104 males/60 females; median age 65.4 yrs; 36-82) and 97 with squamous differentiation (88 males/9 females; median age 68.5 yrs; 44-82). All pts have completed four courses of a platinum compound + gemcitabine (47%) or vinorelbine (53%) at standard doses. The clinical impact of the drug combination administered was evaluated, as % objective response (OR) at the end of the four courses, and as progression-free survival (PFS). Results: In the non-squamous group, the OR: were 62% when the platinum compound was associated with gemcitabine and 65% when the association was with vinorelbine (p = n.s.). In the squamous group, these % were 54 and 57, respectively (p = n.s.). The median PFS for the non-squamous group were: 4.7 months with gemcitabine-, and 4.8 months with vinorelbine-containing doublets, respectively (p = n.s.). In the squamous group the median PFS were 3.8 months with gemcitabine- and 3.5 months with Vinorelbine-containing doublets, respectively (p = n.s.). The difference between the median PFS for the two histological subgroups was statistically significant (p = 0.05), irrespectively from the employed regimen. Conclusions: Our analysis showed that platinum-based doublets with gemcitabine or vinorelbine produced the same OR in all subgroups, without correlation with the histological subtype. However, the median PFS was significantly lower in pts with squamous NSCLC. This confirms the importance of conducting prospective studies aimed to select new therapeutic agents and/or drug combinations for this group of pts. No significant financial relationships to disclose.

Acebrophylline is an airway mucus regulator with antiinflammatory action. The drug’s approach involves several points of attack in obstructive airway disease. The molecule contains ambroxol, which facilitates various steps in the biosynthesis of pulmonary surfactant, theophylline-7 acetic acid whose carrier function raises blood levels of ambroxol, thus rapidly and intensely stimulating surfactant production. The resulting reduction in the viscosity and adhesivity of the mucus greatly improves ciliary clearance. By deviating phosphatidylcholine towards surfactant synthesis, making it no longer available for the synthesis of inflammatory mediators such as the leukotrienes, acebrophylline also exerts an inflammatory effect. This is confirmed in vivo by the reduction in aspecific bronchial hyperresponsiveness in patients with stable bronchial asthma. On a clinical level, acebrophylline is therapeutically effective in patients with acute or chronic bronchitis, chronic obstructive or asthma-like bronchitis and recurrence of chronic bronchitis; it reduces the frequency of episodes of bronchial obstruction and reduces the need for β2-agonists, and improves indexes of ventilatory function.

Background: Pulmonary alveolar proteinosis (PAP) is a rare disease characterised by accumulation of lipoproteinaceous material within alveoli, occurring in three clinically distinct forms: congenital, acquired and secondary. Among the latter, lysinuric protein intolerance (LPI) is a rare genetic disorder caused by defective transport of cationic amino acids. Whole Lung Lavage (WLL) is currently the gold standard therapy for severe cases of PAP. Case presentation: We describe the case of an Italian boy affected by LPI who, by the age of 10, developed digital clubbing and, by the age of 16, a mild restrictive functional impairment associated with a high-resolution computed tomography (HRCT) pattern consistent with pulmonary alveolar proteinosis. After careful assessment, he underwent WLL. Conclusion: Two years after WLL, the patient has no clinical, radiological or functional evidence of pulmonary disease recurrence, thus suggesting that WLL may be helpful in the treatment of PAP secondary to LPI.

To investigate simultaneously localization and relative activity of MMPs during extracellular matrix (ECM) remodeling in bleomycin-induced pulmonary fibrosis in rat, we analyzed the time course of the expression, activity and/or concentration of gelatinases MMP-2 and MMP-9, collagenase MMP-1, matrylisin MMP-7, TIMP-1 and TIMP-2, both in alveolar space (cellular and extracellular compartments) and in lung tissue. MMP and TIMP expression was detected (immunohistochemistry) in lung tissue. MMP activity (zymography) and TIMP concentration (ELISA) were evaluated in lung tissue homogenate (LTH), BAL supernatant (BALs) and BAL cell pellet (BALp) 3, 7, 14, and 28 days after bleomycin intratracheal instillation. Immunohistochemistry showed an extensive MMP and TIMP expression from day 7 in a wide range of structural and inflammatory cells in treated rats. MMP-2 was present mainly in epithelia, MMP-9 in inflammatory cells. MMP-2 and MMP-9 activity was increased respectively in BAL fluid and BAL cells, with a peak at day 7. TIMP-1 and TIMP-2 concentration (ELISA) enhancement was delayed at day 14. In conclusion gelatinases and their inhibitors are significantly activated during bleomycin-induced pulmonary fibrosis. Marked changes in gelatinases activity are observed early in the alveolar compartment, with a prevailing extracellular activity of MMP-2 and a predominant intracellular distribution of MMP-9, while enzyme activity changes in lung parenchyma were less evident. In the repairing phase the reduction of gelatinases activity is synchronous with a peak of alveolar concentration of their inhibitors.

Lung fibrosis is a major cause of mortality and morbidity in systemic sclerosis (SSc). However, its pathogenesis still needs to be elucidated. We examined whether the alteration of certain proteins in bronchoalveolar lavage fluid (BALF) might have a protective or a causative role in the lung fibrogenesis process. For this purpose we compared the BALF protein profile obtained from nine SSc patients with lung fibrosis (SSc_Fib+) with that obtained from six SSc patients without pulmonary fibrosis (SSc_Fib-) by two-dimensional gel electrophoresis (2-DE). Only spots and spot-trains that were consistently expressed in a different way in the two study groups were taken into consideration. In total, 47 spots and spot-trains, corresponding to 30 previously identified proteins in human BALF, showed no significant variation between SSc_Fib+ patients and SSc_Fib- patients, whereas 24 spots showed a reproducible significant variation in the two study groups. These latter spots corresponded to 11 proteins or protein fragments, including serum albumin fragments (13 spots), 5 previously recognized proteins (7 spots), and 4 proteins (3 spots) that had not been previously described in human BALF maps, namely calumenin, cytohesin-2, cystatin SN, and mitochondrial DNA topoisomerase 1 (mtDNA TOP1). Mass analysis did not determine one protein-spot. The two study groups revealed a significant difference in BALF protein composition. Whereas levels of glutathione S-transferase P (GSTP), Cu–Zn superoxide dismutase (SOD) and cystatin SN were downregulated in SSc_Fib+ patients compared with SSc_Fib- patients, we observed a significant upregulation of α1-acid glycoprotein, haptoglobin-α chain, calgranulin (Cal) B, cytohesin-2, calumenin, and mtDNA TOP1 in SSc_Fib+ patients. Some of these proteins (GSTP, Cu–Zn SOD, and cystatin SN) seem to be involved in mechanisms that protect lungs against injury or inflammation, whereas others (Cal B, cytohesin-2, and calumenin) seem to be involved in mechanisms that drive lung fibrogenesis. Even if the 2-DE analysis of BALF did not provide an exhaustive identification of all BALF proteins, especially those of low molecular mass, it allows the identification of proteins that might have a role in lung fibrogenesis. Further longitudinal studies on larger cohorts of patients will be necessary to assess their usefulness as predictive markers of disease.

Background: α1-antitrypsin and surfactant protein-A (SP-A) are major lung defense proteins. With the hypothesis that SP-A could bind α1-antitrypsin, we designed a series ofin vitroexperiments aimed at investigating the nature and consequences of such an interaction.Methods and results: At an α1-antitrypsin:SP-A molar ratio of 1:1, the interaction resulted in a calcium-dependent decrease of 84.6% in the association rate constant of α1-antitrypsin for neutrophil elastase. The findings were similar when SP-A was coupled with the Z variant of α1-antitrypsin. The carbohydrate recognition domain of SP-A appeared to be a major determinant of the interaction, by recognizing α1-antitrypsin carbohydrate chains. However, binding of SP-A carbohydrate chains to the α1-antitrypsin amino acid backbone and interaction between carbohydrates of both proteins are also possible. Gel filtration chromatography and turnover per inactivation experiments indicated that one part of SP-A binds several molar parts of α1-antitrypsin.Conclusion: We conclude that the binding of SP-A to α1-antitrypsin results in a decrease of the inhibition of neutrophil elastase. This interaction could have potential implications in the physiologic regulation of α1-antitrypsin activity, in the pathogenesis of pulmonary emphysema, and in the defense against infectious agents.

A study was carried out in six human volunteers, to assess the blood kinetics of isoniazid, rifampicin and pyrazinamide, administered in a fixed-triple combination intended for use in intermittent chemotherapy of tuberculosis. The formulation employed contained 125 mg of isoniazid (H), 100 mg of rifampicin (R) and 375 mg of pyrazinamide (Z) per tablet; six tablets were administered to every subject, giving a total dosage of 750 mg of isoniazid, 600 mg of rifampicin and 2,250 mg of pyrazinamide. In each subject, the same dose of each drug was administered individually in separate sessions and the results compared. The results indicated that, at the level of dose of the intermittent tablet, no negative interactions between the drugs were observed.