Sebahat Ocak
Université catholique de Louvain
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American Journal of Respiratory and Critical Care Medicine | 2011
Vasiliy V. Polosukhin; Justin M. Cates; William Lawson; Rinat Zaynagetdinov; Aaron P. Milstone; Pierre P. Massion; Sebahat Ocak; Lorraine B. Ware; Jae-Woo Lee; Russell P. Bowler; Alexey V. Kononov; Scott H. Randell; Timothy S. Blackwell
RATIONALE Although airway inflammation can persist for years after smoking cessation in patients with chronic obstructive pulmonary disease (COPD), the mechanisms of persistent inflammation are largely unknown. OBJECTIVES We investigated relationships between bronchial epithelial remodeling, polymeric immunoglobulin receptor (pIgR) expression, secretory IgA (SIgA), airway inflammation, and mural remodeling in COPD. METHODS Lung tissue specimens and bronchoalveolar lavage were obtained from lifetime nonsmokers and former smokers with or without COPD. Epithelial structural changes were quantified by morphometric analysis. Expression of pIgR was determined by immunostaining and real-time polymerase chain reaction. Immunohistochemistry was performed for IgA, CD4 and CD8 lymphocytes, and cytomegalovirus and Epstein-Barr virus antigens. Total IgA and SIgA were measured by ELISA and IgA transcytosis was studied using cultured human bronchial epithelial cells. MEASUREMENTS AND MAIN RESULTS Areas of bronchial mucosa covered by normal pseudostratified ciliated epithelium were characterized by pIgR expression with SIgA present on the mucosal surface. In contrast, areas of bronchial epithelial remodeling had reduced pIgR expression, localized SIgA deficiency, and increased CD4(+) and CD8(+) lymphocyte infiltration. In small airways (<2 mm), these changes were associated with presence of herpesvirus antigens, airway wall remodeling, and airflow limitation in patients with COPD. Patients with COPD had reduced SIgA in bronchoalveolar lavage. Air-liquid interface epithelial cell cultures revealed that complete epithelial differentiation was required for normal pIgR expression and IgA transcytosis. CONCLUSIONS Our findings indicate that epithelial structural abnormalities lead to localized SIgA deficiency in COPD airways. Impaired mucosal immunity may contribute to persistent airway inflammation and progressive airway remodeling in COPD.
Proceedings of the American Thoracic Society | 2009
Sebahat Ocak; Pierre Chaurand; Pierre P. Massion
In an effort to further our understanding of lung cancer biology and to identify new candidate biomarkers to be used in the management of lung cancer, we need to probe these tissues and biological fluids with tools that address the biology of lung cancer directly at the protein level. Proteins are responsible of the function and phenotype of cells. Cancer cells express proteins that distinguish them from normal cells. Proteomics is defined as the study of the proteome, the complete set of proteins produced by a species, using the technologies of large-scale protein separation and identification. As a result, new technologies are being developed to allow the rapid and systematic analysis of thousands of proteins. The analytical advantages of mass spectrometry (MS), including sensitivity and high-throughput, promise to make it a mainstay of novel biomarker discovery to differentiate cancer from normal cells and to predict individuals likely to develop or recur with lung cancer. In this review, we summarize the progress made in clinical proteomics as it applies to the management of lung cancer. We will focus our discussion on how MS approaches may advance the areas of early detection, response to therapy, and prognostic evaluation.
European Respiratory Journal | 2009
Sebahat Ocak; Martin L. Sos; Roman K. Thomas; Pierre P. Massion
During the last decade, high-throughput technologies including genomic, epigenomic, transcriptomic and proteomic have been applied to further our understanding of the molecular pathogenesis of this heterogeneous disease, and to develop strategies that aim to improve the management of patients with lung cancer. Ultimately, these approaches should lead to sensitive, specific and noninvasive methods for early diagnosis, and facilitate the prediction of response to therapy and outcome, as well as the identification of potential novel therapeutic targets. Genomic studies were the first to move this field forward by providing novel insights into the molecular biology of lung cancer and by generating candidate biomarkers of disease progression. Lung carcinogenesis is driven by genetic and epigenetic alterations that cause aberrant gene function; however, the challenge remains to pinpoint the key regulatory control mechanisms and to distinguish driver from passenger alterations that may have a small but additive effect on cancer development. Epigenetic regulation by DNA methylation and histone modifications modulate chromatin structure and, in turn, either activate or silence gene expression. Proteomic approaches critically complement these molecular studies, as the phenotype of a cancer cell is determined by proteins and cannot be predicted by genomics or transcriptomics alone. The present article focuses on the technological platforms available and some proposed clinical applications. We illustrate herein how the “-omics” have revolutionised our approach to lung cancer biology and hold promise for personalised management of lung cancer.
European Respiratory Journal | 2012
Sebahat Ocak; Tetyana V. Pedchenko; Heidi Chen; Frederick T. Harris; Vasiliy V. Polosukhin; Charles Pilette; Yves Sibille; Adriana Gonzalez; Pierre P. Massion
Polymeric immunoglobulin receptor (pIgR) expression is downregulated in lung cancer, but its implications in lung tumourigenesis remain unknown. We hypothesised that loss of pIgR expression occurs early, and is associated with cell proliferation and poor prognosis. pIgR expression was evaluated by immunohistochemistry in airways of patients with normal mucosa, pre-invasive lesions and invasive lesions, and correlated with clinical outcomes. 16-HBE and A549 cells stably transfected with pIgR were tested for proliferation, apoptosis and cell cycle progression. Immunostaining was strong in normal epithelium, but severely reduced in pre-invasive lesions and most lung cancers. Persistent expression was associated with younger age and adenocarcinoma subtype but not survival. pIgR overexpression significantly reduced A549 and 16-HBE proliferation. Growth inhibition was not due to cell cycle arrest, increased apoptosis or endoplasmic reticulum stress, but we observed altered expression of genes encoding for membrane proteins, including NOTCH3. Interestingly, NOTCH3 expression was inversely correlated with pIgR expression in cell lines and tissues. pIgR expression was lost in most lung cancers and pre-invasive bronchial lesions, suggesting that pIgR downregulation is an early event in lung tumourigenesis. pIgR overexpression in A549 and 16-HBE cells inhibited proliferation. Future investigations are required to determine the mechanisms by which pIgR contributes to cell proliferation.
Cancer | 2012
Sebahat Ocak; Heidi Chen; Clay Callison; Adriana Gonzalez; Pierre P. Massion
The focal adhesion kinase (FAK) is a non‐receptor tyrosine kinase linked to tumor growth, invasion, and metastasis. FAK is overexpressed and associated with prognosis in many cancers, but its prognostic value in small‐cell lung carcinoma (SCLC) is unknown and was the focus of this study.
European Respiratory Review | 2010
Sebahat Ocak; Francesco Feoli; Jacques Fastrez; Dominique Butenda; C. Litvine; Idès Colin; Jean Paul d'Odémont
Although pulmonary arterial hypertension is usually associated with advanced stages of sarcoidosis, its occurrence in early stage disease is rare. Herein, a case of associated pulmonary arterial hypertension in the setting of Hashitoxicosis and stage II pulmonary sarcoidosis is reported. The case of associated pulmonary arterial hypertension occurred in a young female without clinically significant medical history and who completely recovered after receiving oral corticotherapy only. Furthermore, this case report suggests the presence of an interaction between pulmonary arterial hypertension, sarcoidosis and Hashitoxicosis.Lipoxygenase, cyclo-oxygenase and cytochrome P450 (CYP) products of arachidonic acid (AA) are implicated in pulmonary vasoregulation. The CYP-mediated epoxyeicosatrienoates (EETs) have been described previously as the predominant eicosanoids in human lungs upon stimulation with the Ca2+ ionophore A23187. In this study, we challenged perfused human lungs with two microbial agents: Escherichia coli haemolysin (ECH) and formyl-methionyl-leucyl-phenylalanine (fMLP). Both stimuli elicited pronounced generation of leukotrienes (LTs), hydroxyeicosatetraenoic acids (HETEs), prostanoids (PTs) and EETs/dihydroxyeicosatrienoic acids (DHETs), as assessed by liquid chromatography–mass spectrometry, paralleled by pulmonary artery pressor response and lung oedema formation. The maximum buffer concentrations of EETs/DHETs surpassed those of LTs plus HETEs and PTs by a factor of four (ECH) or three (AA/fMLP). Dual 5-lipoxygenase/cyclo-oxygenase inhibition caused pronounced reduction of AA/fMLP-induced LT/PT synthesis and oedema formation but only limited attenuation of pulmonary vasoconstriction, while inhibition of CYP epoxygenase clearly attenuated AA/fMLP-induced EET/DHET synthesis and vasoconstriction but not oedema formation, suggesting a major contribution of LTs/PTs to vascular leakage and of EETs/DHETs to pressor response. Consequently, generation of EETs/DHETs is greater than that of LTs plus HETEs and PTs in ex vivo perfused human lungs upon microbial challenge suggesting a substantial contribution of these mediators to inflammatory–infectious pulmonary injury.
Journal of Thoracic Oncology | 2014
Sebahat Ocak; David B. Friedman; Heidi Chen; Jamie A. Ausborn; Mohamed Hassanein; Bruno Detry; Birgit Weynand; Frank Aboubakar; Charles Pilette; Yves Sibille; Pierre P. Massion
Introduction: Small-cell lung cancer (SCLC) is the most aggressive subtype of lung cancer, with no early detection strategy or targeted therapy currently available. We hypothesized that difference gel electrophoresis (DIGE) may identify membrane-associated proteins (MAPs) specific to SCLC, advance our understanding of SCLC biology, and discover new biomarkers of SCLC. Methods: MAP lysates were prepared from three SCLCs, three non–small-cell lung cancers, and three immortalized normal bronchial epithelial cell lines and coanalyzed by DIGE. Subsequent protein identification was performed by mass spectrometry. Proteins were submitted to Ingenuity Pathway Analysis. Candidate biomarkers were validated by Western blotting (WB) and immunohistochemistry (IHC). Results: Principal component analysis on the global DIGE data set demonstrated that the four replicates derived from each of the nine cell lines clustered closely, as did samples within the same histological group. One hundred thirty-seven proteins were differentially expressed in SCLC compared with non–small-cell lung cancer and immortalized normal bronchial epithelial cells. These proteins were overrepresented in cellular/tissue morphology networks. Dihydropyrimidinase-related protein 2, guanine nucleotide–binding protein alpha-q, laminin receptor 1, pontin, and stathmin 1 were selected as candidate biomarkers among MAPs overexpressed in SCLC. Overexpression of all candidates but RSSA in SCLC was verified by WB and/or IHC on tissue microarrays. These proteins were significantly associated with SCLC histology and survival in univariables analyses. Conclusion: DIGE analysis of a membrane-associated subproteome discovered overexpression of dihydropyrimidinase-related protein 2, guanine nucleotide–binding protein alpha-q, RUVB1, and stathmin 1 in SCLC. Results were verified by WB and/or IHC in primary tumors, suggesting that investigating their functional relevance in SCLC progression is warranted. Association with survival requires further validation in larger clinical data sets.
Journal of Vascular and Interventional Radiology | 2016
Sebahat Ocak; Fabrice Duplaquet; Jacques Jamart; Lionel Pirard; Birgit Weynand; Monique Delos; Philippe Eucher; Benoît Rondelet; Michaël Dupont; Luc Delaunois; Yves Sibille; Caroline Dahlqvist
PURPOSE To compare the diagnostic accuracy and safety of a 14-gauge core needle versus a 22-gauge fine needle in the evaluation of thoracic lesions by CT-guided percutaneous transthoracic needle biopsy (TTNB). MATERIALS AND METHODS Medical charts of all patients who underwent CT-guided percutaneous transthoracic core-needle biopsies (CNBs) with a 14-gauge Spirotome device (99 patients, 102 procedures) and fine-needle biopsies (FNBs) with a 22-gauge Rotex needle (92 patients, 102 procedures) between 2007 and 2013 at a single academic institution were retrospectively reviewed. Variables that could influence diagnostic accuracy and safety were collected. RESULTS The overall and cancer-specific diagnostic accuracy rates were 90% and 94%, respectively, with CNB, versus 82% and 89% with FNB. Precise cancer type/subtype was provided by 97% of CNBs versus 65% of FNBs (P < .001). In patients with lung cancer considered for targeted therapy, biomarker analyses were feasible in 80% of CNBs versus 0% of FNBs (P < .001). The rate of pneumothorax was significantly higher with CNB versus FNB (31% vs 19%; P = .004), but chest tube insertion rates were similar (10% vs 11%, respectively). Major bleeding complications occurred in 1% of CNBs versus 2% of FNBs and were associated with one death in the CNB group. CONCLUSIONS Percutaneous transthoracic CNB with a 14-gauge Spirotome needle provided better characterization of cancer lesions and allowed biomarker analyses without a significant increase in major procedural complications.
Lung Cancer | 2016
A. Rosoux; P. Pauwels; Fabrice Duplaquet; Nicky D’Haene; Birgit Weynand; Monique Delos; R. Menon; L.C. Heukamp; Sebahat Ocak
We report a case of crizotinib effectiveness in a heavily pretreated patient with a metastatic NSCLC initially considered IHC-positive and FISH-negative for ALK rearrangement. After repeated analyses of tumor samples, borderline ALK FISH-positivity (18.5% positive cells) was demonstrated.
Chest | 2014
Caroline Dahlqvist; Sebahat Ocak; Jean Paul d'Odémont
In both cases, the stents were positioned on the primary right carina, with the upper arm allowing ventilation and drainage of the upper lobe and simultaneously preventing migration. However, the dimensions and angulation of the upper lobe arm do not always fi t into the right bronchial tree. According to good preliminary results in patients with cancer, 1 , 4 we chose to use the new Oki stent in two patients after lung transplantation. Grade 4 5 bronchus intermedius stenoses developed in a 62-year-old woman and a 55-year-old woman 3 and 2 months, respectively, after bilateral lung transplantation for COPD. Before the Oki stent placement, the fi rst patient underwent fi ve rigid bronchoscopy procedures for dilatation, and the second underwent one procedure. Stenting was performed according to the pulling method, 1 , 4 allowing correct positioning in both cases. Unfortunately, the stent in the second patient was removed accidentally during a fl exible bronchoscopy procedure 1 month later. Given the reoccurrence of the stenosis, a second Oki stent with a longer upper lobe arm was placed to decrease the risk of migration. Both patients experienced immediate symptom relief after stent positioning. Preoperative FEV 1 was 550 mL (33% predicted) for the fi rst patient and 740 mL (33% predicted) for the second, and it increased to 1,050 mL (48% predicted) and 1,500 mL (67% predicted), respectively, 1 week after the intervention. Five months after the procedure, no complications were observed for the fi rst patient. Eight weeks after the second Oki stent placement, the second patient presented with sputum retention and a minimal granulomatous reaction at the distal extremity of the stent. On the basis of this preliminary experience, the new bifurcated silicone stent seems to be a promising and well-tolerated alternative for the treatment of posttransplant bronchus intermedius stenosis.