In vivo imaging models of bone and brain metastases and pleural carcinomatosis with a novel human EML4-ALK lung cancer cell line

がん進展制御研究所EML4-ALK lung cancer accounts for approximately 3-7% of non-small-cell lung cancer cases. To investigate the molecular mechanism underlying tumor progression and targeted drug sensitivity/resistance in EML4-ALK lung cancer, clinically relevant animal models are indispensable. In this study, we found that the lung adenocarcinoma cell line A925L expresses an EML4-ALK gene fusion (variant 5a, E2:A20) and is sensitive to the ALK inhibitors crizotinib and alectinib. We further established highly tumorigenic A925LPE3 cells, which also have the EML4-ALK gene fusion (variant 5a) and are sensitive to ALK inhibitors. By using A925LPE3 cells with luciferase gene transfection, we established in vivo imaging models for pleural carcinomatosis, bone metastasis, and brain metastasis, all of which are significant clinical concerns of advanced EML4-ALK lung cancer. Interestingly, crizotinib caused tumors to shrink in the pleural carcinomatosis model, but not in bone and brain metastasis models, whereas alectinib showed remarkable efficacy in all three models, indicative of the clinical efficacy of these ALK inhibitors. Our in vivo imaging models of multiple organ sites may provide useful resources to analyze further the pathogenesis of EML4-ALK lung cancer and its response and resistance to ALK inhibitors in various organ microenvironments. © 2015 The Authors

Cold start cycling durability of fuel cell stacks for commercial automotive applications

System durability is crucial for the successful commercialization of polymer electrolyte fuel cells (PEFCs) in fuel cell electric vehicles (FCEVs). Besides conventional electrochemical cycling durability during long-term operation, the effect of operation in cold climates must also be considered. Ice formation during start up in sub-zero conditions may result in damage to the electrocatalyst layer and the polymer electrolyte membrane (PEM). Here, we conduct accelerated cold start cycling tests on prototype fuel cell stacks intended for incorporation into commercial FCEVs. The effect of this on the stack performance is evaluated, the resulting mechanical damage is investigated, and degradation mechanisms are proposed. Overall, only a small voltage drop is observed after the durability tests, only minor damage occurs in the electrocatalyst layer, and no increase in gas crossover is observed. This indicates that these prototype fuel cell stacks successfully meet the cold start durability targets for automotive applications in FCEVs

Ability of the Met kinase inhibitor crizotinib and new generation EGFR inhibitors to overcome resistance to EGFR inhibitors

Purpose: Although EGF receptor tyrosine kinase inhibitors (EGFR-TKI) have shown dramatic effects against EGFR mutant lung cancer, patients ultimately develop resistance by multiple mechanisms. We therefore assessed the ability of combined treatment with the Met inhibitor crizotinib and new generation EGFR-TKIs to overcome resistance to first-generation EGFR-TKIs. Experimental Design: Lung cancer cell lines made resistant to EGFR-TKIs by the gatekeeper EGFR-T790M mutation, Met amplification, and HGF overexpression and mice with tumors induced by these cells were treated with crizotinib and a new generation EGFR-TKI. Results: The new generation EGFR-TKI inhibited the growth of lung cancer cells containing the gatekeeper EGFRT790M mutation, but did not inhibit the growth of cells with Met amplification or HGF overexpression. In contrast, combined therapy with crizotinib plus afatinib or WZ4002 was effective against all three types of cells, inhibiting EGFR and Met phosphorylation and their downstream molecules. Crizotinib combined with afatinib or WZ4002 potently inhibited the growth of mouse tumors induced by these lung cancer cell lines. However, the combination of high dose crizotinib and afatinib, but not WZ4002, triggered severe adverse events. Conclusions: Our results suggest that the dual blockade of mutant EGFR and Met by crizotinib and a new generation EGFR-TKI may be promising for overcoming resistance to reversible EGFR-TKIs but careful assessment is warranted clinically. © 2013 Nanjo et al

Accelerated durability testing of fuel cell stacks for commercial automotive applications : a case study

System durability is crucially important for the successful commercialization of fuel cell electric vehicles (FCEVs). Conventional accelerated durability testing protocols employ relatively high voltage to hasten carbon corrosion and/or platinum catalyst degradation. However, high voltages are strictly avoided in commercialized FCEVs such as the Toyota MIRAI to minimize these degradation modes. As such, conventional durability tests are not representative of real-world FCEV driving conditions. Here, modified start-stop and load cycle durability tests are conducted on prototype fuel cell stacks intended for incorporation into commercial FCEVs. Polarization curves are evaluated at beginning of test (BOT) and end of test (EOT), and the degradation mechanisms are elucidated by separating the overvoltages at both 0.2 and 2.2 A cm-2. Using our modified durability protocols with a maximum cell voltage of 0.9 V, the prototype fuel cell stacks easily meet durability targets for automotive applications, corresponding to 15-year operation and 200,000 km driving range. These findings have been applied successfully in the development of new fuel cell systems for FCEVs, in particular the second-generation Toyota MIRAI

Copy Number Alteration and Uniparental Disomy Analysis Categorizes Japanese Papillary Thyroid Carcinomas into Distinct Groups

The aim of the present study was to investigate chromosomal aberrations in sporadic Japanese papillary thyroid carcinomas (PTCs), concomitant with the analysis of oncogene mutational status. Twenty-five PTCs (11 with BRAFV600E, 4 with RET/PTC1, and 10 without mutation in HRAS, KRAS, NRAS, BRAF, RET/PTC1, or RET/PTC3) were analyzed using Genome-Wide Human SNP Array 6.0 which allows us to detect copy number alteration (CNA) and uniparental disomy (UPD), also referred to as copy neutral loss of heterozygosity, in a single experiment. The Japanese PTCs showed relatively stable karyotypes. Seven cases (28%) showed CNA(s), and 6 (24%) showed UPD(s). Interestingly, CNA and UPD were rarely overlapped in the same tumor; the only one advanced case showed both CNA and UPD with a highly complex karyotype. Thirteen (52%) showed neither CNA nor UPD. Regarding CNA, deletions tended to be more frequent than amplifications. The most frequent and recurrent region was the deletion in chromosome 22; however, it was found in only 4 cases (16%). The degree of genomic instability did not depend on the oncogene status. However, in oncogene-positive cases (BRAFV600E and RET/PTC1), tumors with CNA/UPD were less frequent (5/15, 33%), whereas tumors with CNA/UPD were more frequent in oncogene-negative cases (7/10, 70%), suggesting that chromosomal aberrations may play a role in the development of PTC, especially in oncogene-negative tumors. These data suggest that Japanese PTCs may be classified into three distinct groups: CNA+, UPD+, and no chromosomal aberrations. BRAFV600E mutational status did not correlate with any parameters of chromosomal defects

The Common Genetic Variant rs944289 on Chromosome 14q13.3 Associates with Risk of Both Malignant and Benign Thyroid Tumors in the Japanese Population

Background: Several single nucleotide polymorphisms (SNP) have been identified to be associated with the risk for differentiated thyroid cancer in populations of distinct ethnic background. The relationship of these genetic markers to a benign tumor of the thyroid, follicular adenoma (FA), is not well established. Methods: In a multicenter retrospective case-control study, five thyroid cancer-related SNPs - rs966513 (9q22.33, FOXE1), rs944289 (14q13.3, PTCSC3), rs2439302 (8p12, NRG1), rs1867277 (9q22.23, FOXE1), and rs6983267 (8q24, POU5F1B) - were genotyped in 959 cases of histologically verified FA, 535 papillary thyroid carcinomas (PTC), and 2766 population controls. Results: A significant association was found between FA and rs944289 (p=0.002; OR 1.176 [CI 1.064-1.316]), and suggestively with rs2439302 (p=0.033; OR 1.149 [CI 1.010-1.315]). In PTC, significant associations were confirmed for rs965513 (p=4.21E-04; OR 1.587 [CI 1.235-2.000]) and rs944289 (p=0.003; OR 1.234 [CI 1.075-1.408]), newly found for rs2439302 (p=0.003; OR 1.266 [CI 1.087-1.493]) and rs1867277 (p=1.17E-04; OR 1.492 [CI 1.235-1.818]), and was not replicated for rs6983267 (p=0.082; OR 1.136 [CI 0.980-1.316]) in this series. A significant correlation between rs2439302 genotype and relative expression of NRG1 was detected in normal and tumor counterparts of PTC (about 10% decrease per each risk allele). NRG1 expression also significantly correlated with that of PTCSC3. Conclusions: Association of rs944289, which was previously known to confer risk for thyroid cancer, with FA, and the correlation between PTCSC3 and NRG1 expression demonstrates that predisposing genetic factors are partly common for benign and malignant thyroid tumors, and imply broader roles of the pathways they underlie in thyroid tumorigenesis, not limited to carcinogenesis

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target