Inhibition of ABCB1 Overcomes Cancer Stem Cell-like Properties and Acquired Resistance to MET Inhibitors in Non-Small Cell Lung Cancer

Patients with non-small cell lung cancer (NSCLC) EGFR mutations have shown a dramatic response to EGFR inhibitors (EGFR-TKI). EGFR T790M mutation and MET amplification have been recognized as major mechanisms of acquired resistance to EGFR-TKI. Therefore, MET inhibitors have recently been used in NSCLC patients in clinical trials. In this study, we tried to identify the mechanism of acquired resistance to MET inhibitors. We analyzed the antitumor effects of two MET inhibitors, PHA-665752 and crizotinib, in 10 NSCLC cell lines. EBC-1 cells with MET amplification were the only cells that were sensitive to both MET inhibitors. We established PHA-665752-resistant EBC-1 cells, namely EBC-1R cells. Activation of KRAS, EGFR, and FGFR2 signaling was observed in EBC-1R cells by FISH and receptor tyrosine kinase phosphorylation antibody arrays. EBC-1R cells also showed overexpression of ATP-binding cassette subfamily B member 1 (ABCB1) as well as phosphorylation of MET. EBC-1R cells grew as cell spheres that exhibited cancer stem cell-like (CSC) properties and epithelial-mesenchymal transition (EMT). The level of miR-138 that targeted ABCB1 was decreased in EBC-1R cells. ABCB1 siRNA and the ABCB1 inhibitor elacridar could reduce sphere numbers and suppress EMT. Elacridar could also reverse resistance to PHA-665752 in EBC-1R cells. Our study demonstrated that ABCB1 overexpression, which was associated with CSC properties and EMT, was involved in the acquired resistance to MET inhibitors. Inhibition of ABCB1 might be a novel therapeutic strategy for NSCLC patients with acquired resistance to MET inhibitors.

Association between serum lactate levels and early neurogenic pulmonary edema after nontraumatic subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Few studies have described the risk factors associated with the development of neurological pulmonary edema (NPE) after subarachnoid hemorrhage (SAH). We have hypothesized that acute-phase increases in serum lactate levels are associated with the early development of NPE following SAH. The aim of this study was to clarify the association between lactic acidosis and NPE in patients with nontraumatic SAH.

METHODS

We retrospectively evaluated 140 patients with nontraumatic SAH who were directly transported to the Nippon Medical School Hospital emergency room by the emergency medical services. We compared patients in whom NPE developed (NPE group) and those in whom it did not (non-NPE group).

RESULTS

The median (quartiles 1-3) arrival time at the hospital was 32 minutes (28-38 minutes) after the emergency call was received. Although the characteristics of the NPE and non-NPE groups, including mean arterial pressure (121.3 [109.0-144.5] and 124.6 [108.7-142.6] mm Hg, respectively; P=0.96), were similar, the median pH and the bicarbonate ion (HCO3(-)) concentrations were significantly lower in the NPE group than in the non-NPE group (pH, 7.33 [7.28-7.37] vs. 7.39 [7.35-7.43]); P=0.002; HCO3(-), 20.8 [18.6-22.6] vs. 22.8 [20.9-24.7] mmol/L; P=0.01). The lactate concentration was significantly higher in the NPE group (54.0 [40.3-61.0] mg/dL) than in the non-NPE group (28.0 [17.0-37.5] mg/dL; P<0.001). Multivariable regression analysis indicated that younger age and higher glucose and lactate levels were significantly associated with the early onset of NPE in patients with SAH.

CONCLUSION

The present findings indicate that an increased serum lactate level, occurring within 1 hour of the ictus, is an independent factor associated with the early onset of NPE. Multicenter prospective studies are required to confirm our results.

Abstract 756: Inhibition of ABCB1 overcomes cancer stem cell-like properties and acquired resistance to MET inhibitor in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) patients with EGFR mutations have shown a dramatic response to EGFR inhibitors (EGFR-TKI). EGFR T790M mutation and MET amplification have been recognized as mechanisms of acquired resistance to EGFR-TKI. Recently, MET inhibitors have been used in NSCLC patients for clinical trials. In this study, we tried to identify the mechanisms of acquired resistant to MET inhibitor. We analyzed the antitumor effects of two MET inhibitors; PHA-665752 and crizotinib, in 10 NSCLC cell lines. EBC1 cells with MET amplification were only sensitive cells to both of MET inhibitors. We have established PHA-665752 resistant cells; namely EBC1-R cells. EBC1-R cells showed high expression levels of ATP-binding Cassette Sub-family B Member 1 (ABCB1) as wells as phosphorylation MET (p-MET). EBC1-R cells grew as cell sphere that exhibited cancer stem cell-like (CSC) properties and epithelial mesenchymal transition (EMT) feature. Two miRNAs, miR-374a and miR-138 which targeted ABCB1, were decreased in EBC1-R cells. ABCB1 inhibitor elacridar could suppress sphere numbers and EMT phenomenon and restore to the resistance to PHA-665752 in EBC1-R cells. Our study demonstrated that ABCB1 overexpression associated with CSC properties and EMT may be critical for acquire resistance for MET inhibitor. ABCB1 inhibition might be a novel therapeutic strategy for resistance to MET inhibitor in NSCLC cells.

Citation Format: Teppei Sugano, Masahiro Seike, Rintaro Noro, Chie Soeno, Shinji Nakamichi, Nobuhiko Nishijima, Masaru Matsumoto, Susumu Takeuchi, Akihiko Miyanaga, Kaoru Kubota, Akihiko Gemma. Inhibition of ABCB1 overcomes cancer stem cell-like properties and acquired resistance to MET inhibitor in non-small cell lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 756. doi:10.1158/1538-7445.AM2015-756

[Anti-angiogenesis and molecular targeted therapies]

Tumor angiogenesis contributes to the development of tumor progression. Several vascular endothelial growth factor(VEGF)-targeted agents, administered either as single agents or in combination with chemotherapy, have been shown to benefit patients with advanced-stage malignancies. In particular, bevacizumab is a humanized monoclonal antibody that specifically targets VEGF, inhibiting angiogenesis, thereby impeding tumor growth and survival. It is also possible that combined VEGF and the epidermal growth factor (EGFR) pathway blockade could further enhance antitumor efficacy and help prevent resistance to therapy. Preclinical and clinical studies have shown new various molecular targets and the functional characteristics of tumor angiogenesis, which may provide strategies for improving the therapeutic benefit.

Abstract 184: miR-379/411 cluster regulates IL-18 and contributes to drug resistance in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rapidly fatal malignancy that is increasing in incidence in Japan. In this study, we performed gene and microRNA (miRNA) expres¬sion profiling to identify novel therapeutic targets in MPM cells. Based on relative sensitivities to pemetrexed (PEM) and the histone deacetylase (HDAC) inhibitor, vorinostat (SAHA), 211H cells were determined to be the only sensitive MPM cell line out of the 6 tested. On the same series of cell lines, we performed whole genome transcriptomic profiling via DNA microarrays and pathway analysis of the derived data. Of particular note, IL-18 gene expression levels were signifi¬cantly higher in the cell lines that were either drug resistant or displayed intermediate sensitivity, compared to the sensitive 211H cell line. Pathway analysis revealed IL-18 as an impor¬tant gene associated with drug sensitivity of MPM cells. A relationship between IL-18 overexpression and drug resistance was also observed following targeted assessment of 10 cyto¬kine genes using quantitative RT-PCR. miRNA expression profiles were evaluated in the MPM cell line panel in order to discern the mechanism of IL-18 induction in the drug-resistant lines. We found that miR-379 and miR-411 belonged to the same cluster of miRNAs located on chromosome 14q32 that commonly target the IL-18 gene. Luciferase reporter assays revealed that miR-379 and miR-411 directly target the IL-18 gene. Introduction of miR-379 plus miR-411, as well as IL-18 silencing, significantly suppressed the invasive capacity of MESO1 cells in vitro. Furthermore, the use of either PEM or SAHA together with miR-379 plus miR-411 mimics mediated increased sensitivity to these drugs in MESO1 cells. These results suggest that the miR-379/411 cluster may provide new therapeutic opportunities for advanced MPM patients, depending on the nature of IL-18 gene expression.

Citation Format: Akihiko Miyanaga, Masahiro Seike, Kazuo Yamamoto, Susumu Takeuchi, Rintaro Noro, Yuji Minegishi, Kaoru Kubota, Akihiko Gemma. miR-379/411 cluster regulates IL-18 and contributes to drug resistance in malignant pleural mesothelioma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 184. doi:10.1158/1538-7445.AM2015-184

A large-scale prospective registration study of the safety and efficacy of sorafenib tosylate in unresectable or metastatic renal cell carcinoma in Japan: results of over 3200 consecutive cases in post-marketing all-patient surveillance

Objective

Real-life safety and efficacy of sorafenib in advanced renal cell carcinoma in a nationwide patient population were evaluated by post-marketing all-patient surveillance.

Methods

All patients with unresectable or metastatic renal cell carcinoma in Japan who started sorafenib therapy from February 2008 to September 2009 were registered and followed for up to 12 months. Baseline characteristics, treatment status, tumor response, survival and safety data were recorded by the prescribing physicians.

Results

Safety and efficacy were evaluated in 3255 and 3171 patients, respectively. The initial daily dose was 800 mg in 78.2% of patients. Median duration of treatment was 6.7 months and the mean relative dose intensity was 68.4%. Overall, 2227 patients (68.4%) discontinued the treatment by 12 months, half of which (52.0% of discontinued patients) were due to adverse events. The most common adverse drug reactions were hand–foot skin reaction (59%), hypertension (36%), rash (25%) and increase in lipase/amylase (23%). The median progression-free survival was 7.3 months (95% confidence intervals: 6.7–8.1), and the overall survival rate at 1 year was 75.4% (73.5–77.1). Prognostic factors for overall survival were mostly consistent with those in previous clinical trials in the univariate analysis and largely similar to those for progression-free survival and duration of treatment in the multivariate analysis.

Conclusions

Sorafenib for the treatment of advanced renal cell carcinoma under the labeled dose was feasible in daily medical practice, for its acceptable toxicity profile and favorable clinical benefit that were consistent with those in clinical trials.

Marked improvement in leptomeningeal carcinomatosis and spinal cord metastases following alectinib treatment of crizotinib-resistant, ALK-positive lung adenocarcinoma

We report a case of 50-year-old Japanese female with anaplastic lymphoma kinase (ALK)-positive, crizotinib-resistant lung adenocarcinoma, whose leptomeningeal carcinomatosis and spinal cord metastases were dramatically improved by the second-generation ALK inhibitor alectinib. Magnetic resonance imaging (MRI) revealed multiple brain metastases at diagnosis of lung cancer. Carboplatin/paclitaxel/bevacizumab chemotherapy was administered, but enlargement of brain tumors was observed after 3 months. Gamma knife radiosurgery was performed and then the patient received second-line chemotherapy with crizotinib. After 4 months brain MRI revealed the development of leptomeningeal carcinomatosis. Despite the patient undergoing whole brain radiotherapy, spinal cord metastases appeared. Third-line chemotherapy with alectinib was initiated for the management of metastases in central nervous system (CNS) including those in the leptomeninges and spine cord. After 3 months, marked tumor responses were observed in both the leptomeningeal carcinomatosis and spinal cord metastases. This report suggests that alectinib is a promising drug for ALK-positive lung adenocarcinoma with CNS metastases.

Clinical features and risk factors of panitumumab-induced interstitial lung disease: a postmarketing all-case surveillance study

Background

Drug-induced interstitial lung disease (ILD) is one of the most serious adverse reactions associated with the molecularly targeted drugs. Panitumumab has been approved for advanced or recurrent colorectal cancer. Although there were no adverse reaction reports of ILD in panitumumab monotherapy, 4 cases in combination chemotherapy were reported prior to its approval in Japan in 2010. Several studies also reported that the incidence of drug-induced ILD was higher in Japan than in other countries. The clinical features of ILD and the associated risk factors therefore need investigation.

Methods

We analyzed the data from 3085 unresectable, advanced or recurrent colorectal cancer patients enrolled in a postmarketing all-case surveillance study of panitumumab in Japan. ILD case reports were assessed based on the clinical and radiologic findings by a committee of external experts. Multivariate analysis using Cox’s hazard model identified the risk factors.

Results

ILD incidence (1.3 %) and mortality rates (51.3 %) were similar to those of patients receiving another anti-epidermal growth factor receptor (EGFR) monoclonal antibody in Japan. No specific onset timing was determined. Although panitumumab-specific ILD findings were not observed in computed tomography images or clinical practice, panitumumab can induce ILD with diffuse alveolar damage, as do the other anti-EGFR targeting drugs. A history/complication of ILD, male sex, poor general condition, and 65 years or older were identified as ILD risk factors, and no history of previous drug treatment was an apparent risk factor.

Conclusion

Panitumumab-induced ILD can occur at any time after initiation, and close and regular monitoring is needed.

A randomized phase III trial of oral S-1 plus cisplatin versus docetaxel plus cisplatin in Japanese patients with advanced non-small-cell lung cancer: TCOG0701 CATS trial

BACKGROUND

Platinum-based two-drug combination chemotherapy has been standard of care for patients with advanced nonsmall-cell lung cancer (NSCLC). The primary aim was to compare overall survival (OS) of patients with advanced NSCLC between the two chemotherapy regimens. Secondary end points included progression-free survival (PFS), response, safety, and quality of life (QoL).

PATIENTS AND METHODS

Patients with previously untreated stage IIIB or IV NSCLC, an Eastern Cooperative Oncology Group performance status of 0-1 and adequate organ function were randomized to receive either oral S-1 80 mg/m(2)/day on days 1-21 plus cisplatin 60 mg/m(2) on day 8 every 4-5 weeks, or docetaxel 60 mg/m(2) on day 1 plus cisplatin 80 mg/m(2) on day 1 every 3-4 weeks, both up to six cycles.

RESULTS

A total of 608 patients from 66 sites in Japan were randomized to S-1 plus cisplatin (n = 303) or docetaxel plus cisplatin (n = 305). OS for oral S-1 plus cisplatin was noninferior to docetaxel plus cisplatin [median survival, 16.1 versus 17.1 months, respectively; hazard ratio = 1.013; 96.4% confidence interval (CI) 0.837-1.227]. Significantly higher febrile neutropenia (7.4% versus 1.0%), grade 3/4 neutropenia (73.4% versus 22.9%), grade 3/4 infection (14.5% versus 5.3%), and grade 1/2 alopecia (59.3% versus 12.3%) were observed in the docetaxel plus cisplatin than in the S-1 plus cisplatin. There were no differences found in PFS or response between the two arms. QoL data investigated by EORTC QLQ-C30 and LC-13 favored the S-1 plus cisplatin.

CONCLUSION

Oral S-1 plus cisplatin is not inferior to docetaxel plus cisplatin and is better tolerated in Japanese patients with advanced NSCLC.

CLINICAL TRIAL NUMBER

UMIN000000608.

Effective Crizotinib schedule for an elderly patient with ALK rearranged non-small-cell lung cancer: a case report

Background

Non-small-cell lung cancers (NSCLCs) harboring translocations in anaplastic lymphoma kinase (ALK) are highly sensitive to small-molecule ALK kinase inhibitors, such as crizotinib.

Case presentation

We describe a case of post-operative local recurrence of lung adenocarcinoma in an 81 year-old male. He underwent radiation and received chemotherapy with docetaxel, but neither treatment regimen was effective. Following identification of ALK rearrangements, crizotinib treatment was initiated. After treatment with crizotinib for 5 days, adverse events including acute renal failure (grade 2/CTCAE ver4.0) and congestive heart failure (grade 3) occurred. Crizotinib modified treatment was required. Half dose of crizotinib treatment could not control tumor progression. Ultimately, crizotinib was administrated at a dose of 250 mg twice daily every 3 day dosing for 13 months with maintenance of the anti-tumor effect.

Conclusion

This is the first case report that skip schedule was more effective than dose reduction daily in crizotinib administration for ALK rearranged NSCLC patient with severe adverse events.

Control of the MYC-eIF4E axis plus mTOR inhibitor treatment in small cell lung cancer

Background

Mammalian target of rapamycin (mTOR) inhibitors have anti-tumor effects against renal cell carcinoma, pancreatic neuroendocrine cancer and breast cancer. In this study, we analyzed the antitumor effects of mTOR inhibitors in small cell lung cancer (SCLC) cells and sought to clarify the mechanism of resistance to mTOR inhibitors.

Methods

We analyzed the antitumor effects of three mTOR inhibitors including everolimus in 7 SCLC cell lines by MTS assay. Gene-chip analysis, receptor tyrosine kinases (RTK) array and Western blotting analysis were performed to identify molecules associated with resistance to everolimus.

Results

Only SBC5 cells showed sensitivity to everolimus by MTS assay. We established two everolimus resistant-SBC5 cell lines (SBC5 R1 and SBC5 R10) by continuous exposure to increasing concentrations of everolimus stepwise. SPP1 and MYC were overexpressed in both SBC5 R1 and SBC5 R10 by gene-chip analysis. High expression levels of eukaryotic translation initiation factor 4E (eIF4E) were observed in 5 everolimus-resistant SCLC cells and SBC5 R10 cells by Western blotting. MYC siRNA reduced eIF4E phosphorylation in SBC5 cells, suggesting that MYC directly activates eIF4E by an mTOR-independent bypass pathway. Importantly, after reduction of MYC or eIF4E by siRNAs, the SBC5 parent and two SBC5-resistant cells displayed increased sensitivity to everolimus relative to the siRNA controls.

Conclusion

These findings suggest that eIF4E has been shown to be an important factor in the resistance to everolimus in SCLC cells. Furthermore, a link between MYC and mTOR-independent eIF4E contribute to the resistance to everolimus in SCLC cells. Control of the MYC-eIF4E axis may be a novel therapeutic strategy for everolimus action in SCLC.

Final safety and efficacy of erlotinib in the phase 4 POLARSTAR surveillance study of 10 708 Japanese patients with non-small-cell lung cancer

Interstitial lung disease (ILD) occurrence and risk factors were investigated in the Japanese non-small-cell lung cancer, post-marketing, large-scale surveillance study, POLARSTAR. All patients with unresectable, recurrent/advanced non-small-cell lung cancer who were treated with erlotinib in Japan between December 2007 and October 2009 were enrolled. Primary endpoints were patterns of ILD and risk factors for onset of ILD and ILD-related death. Overall survival, progression-free survival, and occurrence of adverse drug reactions were secondary endpoints. Interstitial lung disease was confirmed in 429 (4.3%) patients. Concurrent/previous ILD (hazard ratio, 3.19), emphysema or chronic obstructive pulmonary disease (hazard ratio, 1.86), lung infection (hazard ratio, 1.55), smoking history (hazard ratio, 2.23), and period from initial cancer diagnosis to the start of treatment (<360 days; hazard ratio, 0.58) were identified as significant risk factors for developing ILD by Cox multivariate analysis. Logistic regression analysis identified Eastern Cooperative Oncology Group performance status 2-4 (odds ratio, 2.45 [95% confidence interval, 1.41-4.27]; P = 0.0016), ≤50% remaining normal lung area (odds ratio, 3.12 [1.48-6.58]; P = 0.0029), and concomitant honeycombing with interstitial pneumonia (odds ratio, 6.67 [1.35-32.94]; P = 0.02) as poor prognostic factors for ILD death. Median overall survival was 277 days; median progression-free survival was 67 days. These data confirm the well-characterized safety profile of erlotinib. Interstitial lung disease is still an adverse drug reaction of interest in this population, and these results, including ILD risk factors, give helpful information for treatment selection and monitoring. Erlotinib efficacy was additionally confirmed in this population. (POLARSTAR trial ML21590.).

Relationship between serum cardiac troponin T level and cardiopulmonary function in stable chronic obstructive pulmonary disease

Background

High-sensitivity cardiac troponin T (hs-cTnT) in serum is a useful marker of acute myocardial injury, yet information is limited in patients with chronic obstructive pulmonary disease. We aimed to explore the association between hs-cTnT levels and cardiac and pulmonary dysfunction in patients with stable chronic obstructive pulmonary disease and at-risk individuals.

Methods

We examined community-dwelling adults with/without chronic obstructive pulmonary disease, with a life-long smoking history, current symptoms of dyspnea during exertion, prolonged coughing, and/or sputum. Serum hs-cTnT concentrations were measured, and subjects underwent pulmonary function tests, high-resolution computed tomography of the chest, an echocardiogram, and a 6-minute walking test.

Results

Eighty-six stable patients were identified (mean age 65.5 years; predicted forced expiratory volume in 1 second [FEV₁% predicted] 75.0%). Their overall mean hs-cTnT level was 0.008 ng/mL. Logarithmically transformed hs-cTnT levels significantly and positively correlated with age, smoking index, serum high-sensitivity C-reactive protein levels, right ventricle systolic pressure, low attenuation area percentage, and brain natriuretic peptide levels (range r=0.231–0.534, P=0.000 to P=0.042). Further, logarithmically transformed hs-cTnT values significantly and negatively correlated with forced vital capacity, FEV₁% predicted, diffusion capacity, arterial oxygen tension, and 6-minute walking distance (range r= −0.482 to −0.377, P=0.000 to P=0.002). Multivariate analyses showed that hs-cTnT values varied independently according to the following three parameters: high-sensitivity C-reactive protein levels (B=0.157, β=0.450, t=3.571, P=0.001), age (B=0.008, β=0.352, t=2.789, P=0.009), and right ventricular systolic pressure (B=0.008, β=0.280, t=2.202, P=0.035).

Conclusion

Even in patients with stable chronic obstructive pulmonary disease, the serum troponin T concentration was controlled by at least three major factors, ie, systemic inflammation, advancing age, and right cardiac overload.

Factors associated with a poor response to gefitinib in the NEJ002 study: smoking and the L858R mutation

INTRODUCTION

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) treatment is the standard therapy for non-small cell lung cancer (NSCLC) harbouring EGFR-activating mutations. The NEJ002 phase 3 clinical trial demonstrated the efficacy of EGFR-TKI; gefitinib was significantly superior in both progression-free survival (PFS) and objective response rate (ORR) than carboplatin plus paclitaxel. However, several cases showed no response. In this study, we performed further analysis of the characteristics of these non-responders.

METHODS

Available data from NEJ002 on maximum changes in tumour size were obtained from 103 cases (90.4%) and 110 cases (96.5%) in the carboplatin-paclitaxel and gefitinib groups, respectively. Waterfall plots of maximum tumour size changes were created for non-responders.

RESULTS

Five (4.9%) and 9 (8.2%) cases in the carboplatin-paclitaxel and gefitinib groups were non-responders, respectively. The mean pack years of the non-responders in the carboplatin-paclitaxel and gefitinib groups were 0.33 and 31.7, respectively. The ORR of total smokers (61.5%) and heavy smokers (over 40 pack years, 52.6%) in the gefitinib group were significantly lower compared to people who have never smoked (80.0%) (P=0.044 and P=0.020, respectively). Smoker cases also showed a tendency towards lower PFS and overall survival (OS). In addition, the EGFR common mutation types did not affect PFS and OS in gefitinib-treated cases in NEJ002. However, in this study, the ORR and waterfall plots showed that gefitinib-treated non-responders who had a deletion in exon 19 in the EGFR gene exhibited a tendency towards a higher response compared to those with a L858R mutation.

CONCLUSIONS

NSCLC patients with a smoking history or the EGFR L858R mutation may demonstrate a poorer response to gefitinib treatment.

MET FISH-positive status predicts short progression-free survival and overall survival after gefitinib treatment in lung adenocarcinoma with EGFR mutation

BACKGROUND

Lung adenocarcinoma patients with EGFR gene mutations have shown a dramatic response to gefitinib. However, drug resistance eventually emerges which limits the mean duration of response. With that in view, we examined the correlations between MET gene status as assessed by fluorescence in situ hybridization (FISH) with overall survival (OS) and progression-free survival (PFS) in adenocarcinoma patients with EGFR gene mutations who had received gefitinib therapy.

METHODS

We evaluated 35 lung cancer samples with EGFR mutation from adenocarcinoma patients who had received gefitinib. Gene copy numbers (GCNs) and amplification of MET gene before gefitinib therapy was examined by FISH. MET protein expression was also evaluated by immunohistochemistry (IHC).

RESULTS

FISH assessment showed that of the 35 adenocarcinoma samples, 10 patients (29%) exhibited high polysomy (5 copies≦mean MET per cell) and 1 patient (3%) exhibited amplification (2≦MET gene (red)/CEP7q (green) per cell). IHC evaluation of MET protein expression could not confirm MET high polysomy status. The Eleven patients with MET FISH positivity had significantly shorter progression-free survival (PFS) and overall survival (OS) than the 24 patients who were MET FISH-negative (PFS: p = 0.001 and OS: p = 0.03). Median PFS and OS with MET FISH-positivity were 7.6 months and 16.8 months, respectively, whereas PFS and OS with MET FISH-negativity were 15.9 months and 33.0 months, respectively. Univariate analysis revealed that MET FISH-positivity was the most significant independent factor associated with a high risk of progression and death (hazard ratio, 3.83 (p = 0.0008) and 2.25 (p = 0.03), respectively).

CONCLUSIONS

Using FISH analysis to detect high polysomy and amplification of MET gene may be useful in predicting shortened PFS and OS after Gefitinib treatment in lung adenocarcinoma. The correlation between MET gene status and clinical outcomes for EGFR-TKI should be further evaluated using large scale samples.

β-Catenin-dependent transcription is central to Bmp-mediated formation of venous vessels

β-catenin regulates the transcription of genes involved in diverse biological processes, including embryogenesis, tissue homeostasis and regeneration. Endothelial cell (EC)-specific gene-targeting analyses in mice have revealed that β-catenin is required for vascular development. However, the precise function of β-catenin-mediated gene regulation in vascular development is not well understood, since β-catenin regulates not only gene expression but also the formation of cell-cell junctions. To address this question, we have developed a novel transgenic zebrafish line that allows the visualization of β-catenin transcriptional activity specifically in ECs and discovered that β-catenin-dependent transcription is central to the bone morphogenetic protein (Bmp)-mediated formation of venous vessels. During caudal vein (CV) formation, Bmp induces the expression of aggf1, a putative causative gene for Klippel-Trenaunay syndrome, which is characterized by venous malformation and hypertrophy of bones and soft tissues. Subsequently, Aggf1 potentiates β-catenin transcriptional activity by acting as a transcriptional co-factor, suggesting that Bmp evokes β-catenin-mediated gene expression through Aggf1 expression. Bmp-mediated activation of β-catenin induces the expression of Nr2f2 (also known as Coup-TFII), a member of the nuclear receptor superfamily, to promote the differentiation of venous ECs, thereby contributing to CV formation. Furthermore, β-catenin stimulated by Bmp promotes the survival of venous ECs, but not that of arterial ECs. Collectively, these results indicate that Bmp-induced activation of β-catenin through Aggf1 regulates CV development by promoting the Nr2f2-dependent differentiation of venous ECs and their survival. This study demonstrates, for the first time, a crucial role of β-catenin-mediated gene expression in the development of venous vessels.

Reconsideration of discrepancies between clinical and histopathological features in acute eosinophilic pneumonia

BACKGROUND AND OBJECTIVES

Acute eosinophilic pneumonia (AEP) is a very rare condition, with only one paper published so far discussing histopathological findings at surgical biopsy. In that paper, AEP is considered to be an acute and proliferative stage of DAD accompanied by eosinophilia. However, acute respiratory distress syndrome, acute interstitial pneumonia, and acute exacerbation of idiopathic pulmonary fibrosis, which, unlike AEP are mostly life-threatening diseases, also exhibit DAD. AEP also presents with severe hypoxia but rapidly improves on treatment with corticosteroids alone, without subsequent fibrosis. In contrast, the other above-mentioned diseases with the same histopathology show greatly different clinical courses. The reasons for these differences remain unclear.

METHODS

Here we investigated the histopathology of AEP in 2 surgical lung biopsy and 14 transbronchial lung biopsy cases. Additionally, we determined the presence or absence of different phases of DAD by histopathology in these AEP cases.

RESULTS AND CONCLUSION

Characteristic histopathological findings of AEP consist of alveolar edema with infiltration of eosinophils and lymphocytes and edema of perivascular area and interlobular septa. The alveolar spaces showed fibrinous exudates. There were no hyaline membranes or massive intraluminal fibrosis. These histopathological findings of interstitial edema and fluid exudates are consistent with radiological findings of lung edema and can explain the rapid and complete improvement.Because AEP does not exhibit lung fibrosis histopathologically, it should not to be included in DAD which is associated with lung fibrosis.

Acute Lung Injury Accompanying Alveolar Hemorrhage Associated with Flu Vaccination in the Elderly

Flu vaccinations are administered worldwide every winter for prevention. We herein describe a case of acute lung injury resulting from a pathologically confirmed alveolar hemorrhage, which may have been closely related to a preceding vaccination for pandemic influenza A of 2009/10. The present patient had been hospitalized with an acute lung injury after flu vaccination one year prior to the present hospitalization, however, he received another flu vaccination. We should consider a vaccine-related adverse reaction as a potential cause of pulmonary disease if patients present with this illness during the winter season.

Prognostic significance of PIK3CA and SOX2 in Asian patients with lung squamous cell carcinoma

The recent development of human genome studies has demonstrated the possibility of alteration of several genes as oncogenic driver mutations of lung squamous cell carcinoma (SQCC). FGFR1, PIK3CA and SOX2 genes have been recognized as candidate driver genes of SQCC. The aim of the present study was to evaluate FGFR1, PIK3CA and SOX2 protein expression in SQCC and determine whether the expression of these can be used as prognostic biomarkers. We evaluated the relationships between FGFR1, PIK3CA and SOX2 expression by immunohistochemical analysis and overall survival in lung SQCC patients with stage I-III that originated from China, United States and Japan. FGFR1-positive, PIK3CA-negative and SOX2-positive staining each showed trends toward better survival, although the differences were not statistically significant in a Chinese cohort of 57 patients. Patients with PIK3CA-negative and SOX2-positive staining (PIK3CA(-)/SOX2(+)) showed better prognosis compared with those with PIK3CA-positive or SOX2-negative staining in the Chinese cohort (p=0.04). The robustness of PIK3CA(-)/SOX2(+) classification as having prognostic significance was validated in an independent set of 66 Japanese cohort patients (p=0.007). Japanese SQCC patients with stage I were evaluated separately and PIK3CA(-)/SOX2(+) cases had significantly better survival than the group with PIK3CA-positive or SOX2-negative status (p=0.03). In univariate and multivariable Cox proportional hazards models of Asian stage I patients, the PIK3CA(-)/SOX2(+) classification was statistically significantly associated with survival and was an independent prognostic factor. Classification by PIK3CA and SOX2 protein expression is useful for predicting the prognosis of Asian patients with lung SQCC with stage I.