The MAZ transcription factor is a downstream target of the oncoprotein Cyr61/CCN1 and promotes pancreatic cancer cell invasion via CRAF-ERK signaling.

Myc-associated zinc-finger protein (MAZ) is a transcription factor with dual roles in transcription initiation and termination. Deregulation of MAZ expression is associated with the progression of pancreatic ductal adenocarcinoma (PDAC). However, the mechanism of action of MAZ in PDAC progression is largely unknown. Here, we present evidence that MAZ mRNA expression and protein levels are increased in human PDAC cell lines, tissue samples, a subcutaneous tumor xenograft in a nude mouse model, and spontaneous cancer in the genetically engineered PDAC mouse model. We also found that MAZ is predominantly expressed in pancreatic cancer stem cells. Functional analysis indicated that MAZ depletion in PDAC cells inhibits invasive phenotypes such as the epithelial-to-mesenchymal transition, migration, invasion, and the sphere-forming ability of PDAC cells. Mechanistically, we detected no direct effects of MAZ on the expression of K-Ras mutants, but MAZ increased the activity of CRAF-ERK signaling, a downstream signaling target of K-Ras. The MAZ-induced activation of CRAF-ERK signaling was mediated via p21-activated protein kinase (PAK) and protein kinase B (AKT/PKB) signaling cascades and promoted PDAC cell invasiveness. Moreover, we found that the matricellular oncoprotein cysteine-rich angiogenic inducer 61 (Cyr61/CCN1) regulates MAZ expression via Notch-1-sonic hedgehog signaling in PDAC cells. We propose that Cyr61/CCN1-induced expression of MAZ promotes invasive phenotypes of PDAC cells not through direct K-Ras activation but instead through the activation of CRAF-ERK signaling. Collectively, these results highlight key molecular players in PDAC invasiveness and may help inform therapeutic strategies to improve clinical management and outcomes of PDAC.

Spectrum of Pulmonary Manifestations in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis on Chest CT.

Plain language summary (for Research Letters only): Antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis has many clinical manifestations and pulmonary complications such as pulmonary fibrosis. We hypothesized that patients with ANCA-associated vasculitis would have radiographic evidence of a wide range of pulmonary abnormalities on CT and that ANCA titer would be associated with these pulmonary abnormalities.

Neutrophil extracellular traps linked to idiopathic pulmonary fibrosis severity and survival.

Background: Idiopathic pulmonary fibrosis (IPF) leads to progressive loss of lung function and mortality. Understanding mechanisms and markers of lung injury in IPF is paramount to improving outcomes for these patients. Despite the lack of systemic involvement in IPF, many analyses focus on identifying circulating prognostic markers. Using a proteomic discovery method followed by ELISA validation in multiple IPF lung compartments and cohorts we explored novel markers of IPF survival. Methods: In our discovery analysis, agnostic label-free quantitative proteomics differentiated lung tissue protein expression based on survival trajectory (n=10). Following selection of the candidate pathway (neutrophil extracellular trap (NET) formation), we subsequently validated the presence of NETs in the IPF lung microenvironment using fully quantitative assays of known NET remnants in separate IPF cohorts (n=156 and n=52) with bronchoalveolar lavage fluid. We then assessed the correlation of these markers with baseline pulmonary function and survival. Results: Discovery lung tissue proteomics identified NET formation as significantly associated with poor IPF survival. Using fully quantitative confirmatory tests for reproducibility we confirmed the presence of NET markers in IPF BALF and found significant correlations with worse pulmonary function in both cohorts (p<0.03 and p = 0.04 respectively). In the survival cohort, higher levels of NET markers predicted worse survival after adjusting for gender, age, and baseline physiologic severity (hazard ratio range: 1.79-2.19). Conclusions: NET markers were associated with disease severity and worse survival in IPF. These findings suggest NET formation contributes to lung injury and decreased survival in IPF and may represent a potential therapeutic target.

Proteomic profiling of bronchoalveolar lavage fluid uncovers protein clusters linked to survival in idiopathic forms of interstitial lung disease.

Background: Idiopathic interstitial pneumonias (IIPs) such as idiopathic pulmonary fibrosis (IPF) and interstitial pneumonia with autoimmune features (IPAF), present diagnostic and therapeutic challenges due to their heterogeneous nature. This study aimed to identify intrinsic molecular signatures within the lung microenvironment of these IIPs through proteomic analysis of bronchoalveolar lavage fluid (BALF). Methods: Patients with IIP (n=23) underwent comprehensive clinical evaluation including pre-treatment bronchoscopy and were compared to controls without lung disease (n=5). Proteomic profiling of BALF was conducted using label-free quantitative methods. Unsupervised cluster analyses identified protein expression profiles which were then analyzed to predict survival outcomes and investigate associated pathways. Results: Proteomic profiling successfully differentiated IIP from controls. k-means clustering, based on protein expression revealed three distinct IIP clusters, which were not associated with age, smoking history, or baseline pulmonary function. These clusters had unique survival trajectories and provided more accurate survival predictions than the Gender Age Physiology (GAP) index (C-index 0.794 vs. 0.709). The cluster with the worst prognosis featured decreased inflammatory signaling and complement activation, with pathway analysis highlighting altered immune response pathways related to immunoglobulin production and B cell-mediated immunity. Conclusions: The unsupervised clustering of BALF proteomics provided a novel stratification of IIP patients, with potential implications for prognostic and therapeutic targeting. The identified molecular phenotypes underscore the diversity within the IIP classification and the potential importance of personalized treatments for these conditions. Future validation in larger, multi-ethnic cohorts is essential to confirm these findings and to explore their utility in clinical decision-making for patients with IIP.

Airways Abnormalities in a Prospective Cohort of Patients With Rheumatoid Arthritis.

BACKGROUND: Rheumatoid arthritis (RA) affects roughly 1% of the population and commonly involves the lungs. Of lung involvement in RA, interstitial lung disease (ILD) is well known; however, airways disease in RA is relatively understudied. RESEARCH QUESTION: What are the baseline airways abnormalities in a prospective cohort of patients with RA based on pulmonary function testing (PFT) results, high-resolution CT (HRCT) scans, and computational imaging analysis and are there associations between these abnormalities and respiratory symptoms? STUDY DESIGN AND METHODS: In this single-center study, 188 patients with RA without a clinical diagnosis of ILD underwent HRCT imaging and PFT. Radiologists assessed HRCT scans for airway abnormalities. Computational imaging via VIDA Vision software and in-house quantitative CT imaging analysis was applied to 147 HRCT scans to quantify airway abnormalities. RESULTS: Airways obstruction (FEV1 to FVC ratio < 0.7) was present in 20.7% of patients and was associated with older age, male sex, and higher smoking rate. Radiologists identified airway abnormalities in 61% of patients: 55% had bronchial wall thickening, 12% had bronchiectasis, and 5% had mosaic attenuation. These airways findings were associated with older age; male sex; lower FEV1, FVC, and FEV1 to FVC ratio; and higher rates of rheumatoid factor positivity. Prespecified quantitative CT scan metrics (wall thickening percentage and emphysema percentage) correlated with obstruction in PFT results and more severe respiratory symptoms, including shortness of breath and cough. INTERPRETATION: High rates of airways abnormalities were found in this prospective RA cohort based on 3 methods of detection. Significant associations were identified between quantitative CT scan measures and respiratory symptoms. Airways disease may be an underrecognized extra-articular manifestation of RA and quantitative CT imaging may be a sensitive method to detect the clinical impact on respiratory symptoms.