Choon Taek Lee

Clinical and molecular evidences of epithelial to mesenchymal transition in acquired resistance to EGFR-TKIs.

BACKGROUNDnEpithelial-to-mesenchymal transition (EMT), which was related with an acquired resistance to gefitinib, was found in the A549 lung cancer cell line. However, the clinical feasibility of this finding is still questionable. Here, we investigated whether EMT could be detected in a more clinically suitable situation using patients tumor and cells with deletion mutation on exon 19 of EGFR gene.nnnMETHODSnHCC827 cell line was used to establish the subline resistant to EGFR-TKIs. The induction of EMT was analyzed by immunostainings and Western blots in resistant cells and biopsied tissue from a patient with acquired resistance to erlotinib. Migration and invasion assay was performed to characterize the resistant cells. EMT-related genes expression was evaluated by cDNA microarray. Phospho-receptor tyrosine kinase array analysis was carried out to find bypass activating signals such as MET.nnnRESULTSnWe found that EMT developed in a lung cancer patient who had an acquired resistance to erlotinib while there were no known resistant mechanisms such as T790M and MET amplification. CL-387,785-resistant cells (HCC827/CLR) were obtained by long-term exposure to increasing concentrations of CL-387,785 (an irreversible EGFR-TKI). The morphological and molecular maker changes compatible with EMT were also found in HCC827/CLR cells. However, there were also no secondary T790M mutation and MET amplification. Furthermore, the activity of most of tested RTKs including receptor HER family was decreased suggesting that there was no bypass activating signal leading to resistance. These cells showed an enhanced capability for migration (∼1.6-fold) and invasion (∼2.8-fold).nnnCONCLUSIONnEMT should be considered as one of possible mechanisms for the acquired resistance to EGFR-TKIs in lung cancer cells.

Islet isolation from adult designated pathogen‐free pigs: use of the newer bovine nervous tissue–free enzymes and a revised donor selection strategy would improve the islet graft function

Jin S‐M, Shin JS, Kim KS, Gong C‐H, Park SK, Kim J‐S, Yeom S‐C, Hwang ES, Lee CT, Kim S‐J, Park C‐G. Islet isolation from adult designated pathogen‐free pigs: use of the newer bovine nervous tissue–free enzymes and a revised donor selection strategy would improve the islet graft function. Xenotransplantation 2011; 18: 369–379.

Successful removal of endobronchial blood clots using bronchoscopic cryotherapy at bedside in the intensive care unit.

Acute airway obstruction after hemoptysis occurs due to the presence of blood clots. These conditions may result in life-threatening ventilation impairment. We report a case of obstruction of the large airway by endobronchial blood clots which were removed using bronchoscopic cryotherapy at the bedside of intensive care unit. A 66-year-old female with endometrial cancer who had undergone chemotherapy, was admitted to the intensive care unit due to neutropenic fever. During mechanical ventilation, the minute ventilation dropped to inadequately low levels and chest radiography showed complete opacification of the left hemithorax. Flexible bronchoscopy revealed large blood clots obstructing the proximal left main bronchus. After unsuccessful attempts to remove the clots with bronchial lavage and forceps extraction, blood clots were removed using bronchoscopic cryotherapy. This report shows that cryotherapy via flexible bronchoscopy at the bedside in the intensive of intensive care unit is a simple and effective alternative for the removal of endobronchial blood clots.

The detection of peripheral lung cancer by MAGE A1-6 RT-nested PCR in bronchial washing specimens

BACKGROUNDnWith expansion of lung cancer screening by computed tomography (CT) and increased incidence of adenocarcinoma, we encountered more peripheral nodules to be identified. We evaluated detection rates of the melanoma antigen genes (MAGE) RT-nested PCR using a common MAGE A1-6 primer in bronchoscopic washing samples from patients with bronchoscopically invisible peripheral nodules, and compared with those of conventional cytology and percutaneous needle aspiration biopsy (PCNB).nnnMATERIALS AND METHODSnForty-two patients with bronchoscopically invisible peripheral lung nodules were studied. Bronchoscopic washing specimens were collected by instilling 20ml of normal saline into a tumor bearing segment and retrieving samples. Samples were split and analyzed by MAGE RT-PCR and conventional cytology. A PCNB was performed in all but two patients. Twenty-eight lesions were diagnosed as lung cancers and 14 as benign lung diseases. We evaluated MAGE A1-6 RT-nested PCR, cytology, and PCNB results and analyzed them according to histologic cell types and tumor sizes.nnnRESULTSnIn bronchial washing samples, the detection rates of MAGE A1-6 RT-nested PCR (67.9%) were higher than that of conventional cytology (21.4%, p=.04) and similar to that of PCNB (73.1%, p=.45) in 28 cancer patients. In terms of histologic types, the detection rates of MAGE A1-6 RT-nested PCR, conventional cytology, and PCNB were 78.6%, 21.4% and 64.3% in adenocarcinoma, 70%, 20% and 77.8% in squamous cell carcinoma, respectively. The sensitivity of conventional cytology was significantly lower than that of MAGE RT-nested PCR or PCNB regardless of tumor histology p=.04, p=.025, respectively, in adenocarcinoma; p=.035, p=.04, respectively, in squamous cell carcinoma). In terms of tumor size, the corresponding detection rates were 73.3%, 6.7% and 73.3% for tumors smaller than 3cm (N=15), and 61.5%, 38.5% and 72.7% for tumors larger than 3cm (N=13).nnnCONCLUSIONSnMAGE A1-6 RT-nested PCR showed higher detection rates in the bronchial washes of peripheral lung cancer patients than conventional cytology testing. This method is simple and robust, and it could be effectively utilized as a peripheral lung cancer detection tool in clinical laboratories.

Cytoplasmic YAP Expression is Associated with Prolonged Survival in Patients with Lung Adenocarcinomas and Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Treatment

BackgroundYes-associated protein (YAP) has been reported to be associated with the prognosis of various cancers and also to affect epidermal growth factor receptor–tyrosine kinase inhibitor (EGFR–TKI) activity in ovarian cancer cell lines. However, few studies have evaluated YAP protein expression in lung cancer, and the results have lacked consistency.MethodsYAP expression was evaluated in a total of 205 curatively resected lung adenocarcinomas and 36 cases of EGFR-mutated TKI-treated patients. Correlations between the expression of YAP and clinicopathologic features, response to EGFR–TKI treatment, and prognostic significance were analyzed.ResultsHigh cytoplasmic YAP expression was positively correlated with the clinicopathologic parameters that have been associated with favorable prognosis. Multivariate analysis revealed that high cytoplasmic YAP expression was an independent prognostic factor in lung adenocarcinomas (progression-free survival: hazard ratio [HR] 0.659; 95xa0% confidence interval [CI] 0.431–1.010; pxa0=xa00.050; overall survival: HR, 0.474; 95xa0% CI 0.263–0.854; pxa0=xa00.013) and EGFR-TKI-treated patients with EGFR mutation (progression-free survival: HR, 0.346; 95xa0% CI 0.146–0.818; pxa0=xa00.016; overall survival: HR, 0.291; 95xa0% CI 0.125–0.676; pxa0=xa00.004).ConclusionsHigh cytoplasmic YAP expression predicted a good clinical outcome for patients with lung adenocarcinoma and in EGFR–TKI-treated patients. Therefore, YAP may play a role in EGFR–TKI-treated lung cancer, and YAP targeting may enhance therapeutic effects in combination with other cancer drugs.

Impact of mediastinal lymph node enlargement on the prognosis of idiopathic pulmonary fibrosis

Background Mediastinal lymph node enlargement (LNE) is common in idiopathic pulmonary fibrosis (IPF) and is known to be associated with the severity of lung fibrosis. However, the relationship between mediastinal LNE and the prognosis of IPF has not been determined to date. Methods This study included patients with IPF from the interstitial lung disease registry at Seoul National University Bundang Hospital, from January 2012 to March 2016. Two thoracic radiologists independently reviewed mediastinal LNE and lung parenchymal fibrosis and ground glass opacities in chest computed tomography scans of each patient, which were obtained upon diagnosis. Mortality and admission rates were analyzed. Results In total, 132 patients (104 [78.8%] male; median age, 72 years; range, 51–84 years) were enrolled and 73 (55.3%) patients had mediastinal LNE (short axis ≥ 10 mm in diameter). Mortality was significantly higher among patients with LNE than among those without LNE (hazard ratio 2.26 [95% confidence interval 1.20–4.23], p = 0.011). Of the patients with LNE, 24.7% experienced acute exacerbation and 43.8% experienced hospital admission for respiratory causes, in comparison with 16.9% and 40.0% of patients without LNE respectively. Although patients with LNE had a tendency to have increased rate of acute exacerbation, it was not statistically significant. Conclusion Mediastinal LNE in IPF is associated with increased mortality and its occurrence may be considered a poor prognostic factor in patients with IPF.

199PDISTINCT EXPRESSION PATTERN AND PROGNOSTIC SIGNIFICANCE OF STEM CELL-RELATED MARKERS BETWEEN LUNG ADENOCARCINOMA AND SQUAMOUS CELL CARCINOMA

ABSTRACT Aim: The cancer stem cell (CSC) hypothesis asserts that only a small subset of cells within a tumor is capable of both tumor initiation and sustainment. CSCs may be naturally resistant to the cytotoxic effect of radio-chemotherapy because of slow cell cycling, lower proliferation, and increased expression of DNA repair and antiapoptotic genes. Although many CSC markers have been reported, the clinicopathological implications in lung cancer are controversial. The aim of this study is to investigate the expression and clinical significance of representative CSC markers in non-small cell lung cancer (NSCLC). Methods: A total of 449 surgically resected NSCLC specimens including 253 adenocarcinomas (ADC) and 163 squamous cell carcinomas (SqCC) were enrolled. Immunohistochemistry for CD133, CD44, aldehyde dehydrogenase 1 (ALDH1), nanog, Octamer-4 (OCT4), sex-determining region Y-box 2 (SOX2), CXCR4, CD117 (C-kit) was performed using tissue microarray. Correlations between the expression of CSC markers and clinicopathologic, molecular features and survival analysis were performed. Results: High expression of CD133, ALDH1 and CD44 was correlated with the lower pathologic stage (p = 0.008, 0.037 and 0.024, respectively), absence of lymphovascular invasion (p = 0.004, Conclusions: Lung ADC and SqCC showed distinct expression profiles and prognostic significance of CSC markers. High nanog expression was an independent poor prognostic marker in lung ADC, which may present a new therapeutic target for lung ADC patients. Disclosure: All authors have declared no conflicts of interest.