The tumor-promoting fibrotic stroma rich in tumor-associated fibroblasts (TAF) is drawing increased therapeutic attention. Intriguingly, a trial with the antifibrotic drug nintedanib in nonsmall cell lung cancer reported clinical benefits in adenocarcinoma (ADC) but not squamous cell carcinoma (SCC), even though the stroma is fibrotic in both histotypes. Likewise, we reported that nintedanib inhibited the tumor-promoting fibrotic phenotype of TAFs selectively in ADC. Here we show that tumor fibrosis is actually higher in ADC-TAFs than SCC-TAFs in vitro and patient samples. Mechanistically, the reduced fibrosis and nintedanib response of SCC-TAFs was associated with increased promoter methylation of the profibrotic TGFb transcription factor SMAD3 compared with ADC-TAFs, which elicited a compensatory increase in TGFb1/SMAD2 activation. Consistently, forcing global DNA demethylation of SCC-TAFs with 5-AZA rescued TGFb1/SMAD3 activation, whereas genetic downregulation of SMAD3 in ADC-TAFs and control fibroblasts increased TGFb1/SMAD2 activation, and reduced their fibrotic phenotype and antitumor responses to nintedanib in vitro and in vivo. Our results also support that smoking and/or the anatomic location of SCC in the proximal airways, which are more exposed to cigarette smoke particles, may prime SCC-TAFs to stronger SMAD3 epigenetic repression, because cigarette smoke condensate selectively increased SMAD3 promoter methylation. Our results unveil that the histotype-specific regulation of tumor fibrosis in lung cancer is mediated through differential SMAD3 promoter methylation in TAFs and provide new mechanistic insights on the selective poor response of SCC-TAFs to nintedanib. Moreover, our findings support that patients with ADC may be more responsive to antifibrotic drugs targeting their stromal TGFb1/SMAD3 activation.Significance: This study implicates the selective epigenetic repression of SMAD3 in SCC-TAFs in the clinical failure of nintedanib in SCC and supports that patients with ADC may benefit from antifibrotic drugs targeting stromal TGFb1/ SMAD3.
(1) Methotrexate is an effective steroid-sparing agent. (2) A dosage lower than the one recommended in the literature is effective. (3) Tolerance is good. (4) No benefit or detrimental effects in bone metabolism were observed after one year.
BackgroundFew studies have investigated the independent effects of occupational exposures and smoking on chronic bronchitis and airflow obstruction. We assessed the association between lifetime occupational exposures and airflow obstruction in a cross-sectional survey in an urban-industrial area of Catalonia, Spain.MethodsWe interviewed 576 subjects of both sexes aged 20–70 years (response rate 80%) randomly selected from census rolls, using the ATS questionnaire. Forced spirometry was performed by 497 subjects according to ATS normative.ResultsLifetime occupational exposure to dust, gases or fumes was reported by 52% of the subjects (63% in men, 41% in women). Textile industry was the most frequently reported job in relation to these exposures (39%). Chronic cough, expectoration and wheeze were more prevalent in exposed subjects with odds ratios ranging from 1.7 to 2.0 being highest among never-smokers (2.1 to 4.3). Lung function differences between exposed and unexposed subjects were dependent on duration of exposure, but not on smoking habits. Subjects exposed more than 15 years to dusts, gases or fumes had lower lung function values (FEV1 -80 ml, 95% confidence interval (CI) -186 to 26; MMEF -163 ml, CI -397 to 71; FEV1/FVC ratio -1.7%, CI -3.3 to -0.2) than non-exposed.ConclusionChronic bronchitis symptoms and airflow obstruction are associated with occupational exposures in a population with a high employment in the textile industry. Lung function impairment was related to the duration of occupational exposure, being independent of the effect of smoking.
To determine the usefulness of samples obtained by bronchoalveolar lavage (BAL) in establishing the diagnosis of ventilator-associated pneumonia, quantitative cultures of BAL and protected specimen brush (PSB) samples obtained via fiberoptic bronchoscope were compared in 42 patients with suspected ventilator-associated pneumonia. Direct examination of BAL fluid was also used to identify cells with intracellular organisms. Ventilator-associated pneumonia was diagnosed in 18 patients; a total of 39 microorganisms were recovered from BAL fluid and 29 from PSB specimens. Cultures of 21 BAL and 23 PSB specimens were sterile. Quantitative BAL and PSB cultures coincided in 76% of cases. Sterile BAL and PSB cultures agreed in 87% of cases. Cultures were completely discordant in only three cases. The sensitivity of BAL for diagnosis of ventilator-associated pneumonia using bacterial counts of > or = 10(4) cfu/ml was 89%, and specificity was 100%. In 14 of the 18 patients with ventilator-associated pneumonia, the percentage of cells containing intracellular organisms in specimens recovered by BAL was 11.6% versus 0.45% in patients without pneumonia (p < 0.05). In the remaining four patients, all of whom had Pseudomonas aeruginosa pneumonia, no intracellular organisms could be detected. Using a cut-off point of > or = 5% of cells with intracellular organisms, the sensitivity and specificity for the early diagnosis of ventilator-associated pneumonia was 67% and 96%, respectively. The results confirm the usefulness of the quantitative BAL culture (with a cut-off at 10(4) cfu/ml) for the diagnosis of ventilator-associated pneumonia. The identification of intracellular organisms in BAL fluid is a good early indicator of pneumonia, but the sensitivity of this technique may be lower for Pseudomonas aeruginosa infections.
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