Published papers

EGFR-mutated lung cancers account for a significant subgroup of non-small cell lung cancers overall. Third-generation EGFR tyrosine kinase inhibitors (TKI) are mutation-selective inhibitors with minimal effects on wild-typeEGFR. Acquired resistance develops to these agents, however, the mechanisms are as yet uncharacterized. In this study, we report that the Src-AKT pathway contributes to acquired resistance to these TKI. In addition, amplification of EGFR wild-type alleles but not mutant alleles was sufficient to confer acquired resistance. These findings underscore the importance of signals from wild-type EGFR alleles in acquiring resistance to mutant-selective EGFR-TKI. Our data provide evidence of wildtype allele-mediated resistance, a novel concept of acquired resistance in response to mutation-selective inhibitor therapy in cancer treatment. (C) 2017 AACR.

Fibroblast growth factor 9 (FGF9) is essential for lung development and is highly expressed in a subset of human lung adenocarcinomas. We recently described a mouse model in which FGF9 expression in the lung epithelium caused proliferation of the airway epithelium at the terminal bronchioles and led to rapid development of adenocarcinoma. Here, we used this model to characterize the effects of prolonged FGF9 induction on the proximal and distal lung epithelia, and examined the propagation potential of FGF9-induced lung tumours. We showed that prolonged FGF9 over-expression in the lung resulted in the development of adenocarcinomas arising from both alveolar type II and airway secretory cells in the lung parenchyma and airways, respectively. We found that tumour cells harboured tumour-propagating cells that were able to form secondary tumours in recipient mice, regardless of FGF9 expression. However, the highest degree of tumour propagation was observed when unfractionated tumour cells were co-administered with autologous, tumour-associated mesenchymal cells. Although the initiation of lung adenocarcinomas was dependent on activation of the FGF9-FGF receptor 3 (FGFR3) signalling axis, maintenance and propagation of the tumour was independent of this signalling. Activation of an alternative FGF-FGFR axis and the interaction with tumour stromal cells is likely to be responsible for the development of this independence. This study demonstrates the complex role of FGF-FGFR signalling in the initiation, growth and propagation of lung cancer. Our findings suggest that analysing the expressions of FGF-FGFRs in human lung cancer will be a useful tool for guiding customized therapy. Copyright (c) 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR-TKIs) were developed to overcome EGFR T790M-mediated resistance to first- and second-generation EGFR-TKIs. Third-generation EGFR-TKIs, such as osimertinib and nazartinib, are effective for patients with the EGFR T790M mutation. However, there are no direct comparison data to guide the selection of a thirdgeneration EGFR-TKI for patients with different EGFR mutations. We previously established an in vitro model to estimate the therapeutic windows of EGFR-TKIs by comparing their relative efficacies against cells expressing mutant or wild type EGFRs. The present study used this approach to characterize the efficacy of third-generation EGFR-TKIs and compare them with that of other EGFR-TKIs. Treatment efficacy was examined using human lung cancer-derived cell lines and Ba/F3 cells, which were transduced with clinically relevant mutant EGFRs. Interestingly, mutation-related differences in EGFR-TKI sensitivity were observed. For classic EGFR mutations (exon 19 deletion and L858R, with or without T790M), osimertinib showed lower IC50 values and wider therapeutic windows than nazartinib. For less common EGFR mutations (G719S or L861Q), afatinib showed the lowest IC50 values. For G719S+T790M or L861Q+T790M, the IC50 values of osimertinib and nazartinib were around 100 nM, which was 10- to 100-fold higher than those for classic+T790M mutations. On the contrary, osimertinib and nazartinib showed similar efficacies in cells expressing EGFR exon 20 insertions. The findings highlight the diverse mutation-related sensitivity pattern of EGFR-TKIs. These data may help in the selection of EGFR-TKIs for non-small cell lung cancer patients harboring EGFR mutations.

Gastroenteropancreatic (GEP) neuroendocrine neoplasm (NEN) that consists of neuroendocrine tumor and neuroendocrine carcinoma (NEC) is a lethal but under-investigated disease owing to its rarity. To fill the scarcity of clinically relevant models of GEP-NEN, we here established 25 lines of NEN organoids and performed their comprehensive molecular characterization. GEP-NEN organoids recapitulated pathohistological and functional phenotypes of the original tumors. Whole-genome sequencing revealed frequent genetic alterations in TP53 and RB1 in GEP-NECs, and characteristic chromosome-wide loss of heterozygosity in GEP-NENs. Transcriptome analysis identified molecular subtypes that are distinguished by the expression of distinct transcription factors. GEP-NEN organoids gained independence from the stem cell niche irrespective of genetic mutations. Compound knockout of TP53 and RB1, together with overexpression of key transcription factors, conferred on the normal colonic epithelium phenotypes that are compatible with GEP-NEN biology. Altogether, our study not only provides genetic understanding of GEP-NEN, but also connects its genetics and biological phenotypes. Gastroenteropancreatic neuroendocrine neoplasms are a rare but lethal cancer with a scarcity of clinically relevant models. Kawasaki et al. establish and characterize 25 organoid lines to identify molecular subtypes with genotype-phenotype mapping.

Objectives: Several preclinical data proposed a potential efficacy of osimertinib, a third-generation EGFR tyrosine kinase inhibitor, for EGFR exon 20 insertion (EGFR ex20ins)-positive non-small cell lung cancer (NSCLC). However, reported case series and a retrospective study proposed controversial efficacy. The efficacy of osimertinib in EGFR ex20ins-positive NSCLC have not been well evaluated in prospective clinical trials. In this study, we performed a prospective, single-arm, multi-center, open-label, non-randomized phase I/II study to evaluate efficacy of osimertinib for EGFR ex20ins-positive NSCLC. Materials and methods: From August 2018 to January 2020, 14 NSCLC patients with EGFR ex20ins were enrolled, of whom 2 were excluded because they did not meet the inclusion criteria. Efficacy and safety of 80 mg osimertinib were evaluated. In addition, we performed a translational exploratory study to clarify the association of mutation type-specific drug sensitivity, osimertinib pharmacokinetic data, and clinical efficacy. Results: Of the evaluated patients, none experienced objective response, 7 experienced stable disease (58.3%), and 5 experienced disease progression (41.7%). The median progression free survival (PFS) was 3.8 months, and the median overall survival was 15.8 months. Interestingly, the exploratory study demonstrated statistically significant positive correlation between plasma osimertinib concentration/in vitro IC50 ratio and PFS (R = 0.9912, P = 0.0001), highlighting the mutation type-specific concentration-dependent efficacy of osimertinib for EGFR ex20ins-positive NSCLC. Conclusions: Regular dose, 80 mg/day, of osimertinib has limited clinical activity in NSCLC patients with EGFR ex20ins. The translational study proposed the potential efficacy of higher dose osimertinib in a subgroup of EGFR ex20ins-positive NSCLC.

Background: Chronic obstructive pulmonary disease (COPD) is frequently associated with cachexia, leading to poor prognoses and reduced quality of life. However, the mechanisms underlying adipose tissue atrophy, its pathological significance and its interaction with skeletal muscle remain poorly understood. We hypothesised that adipose tissue atrophy precedes muscle wasting in COPD-associated cachexia, and muscle atrophy progresses through adipose–muscle crosstalk. Methods: We analysed chest computed tomography scans of 185 patients with COPD to quantify the cross-sectional areas of the pectoralis muscle (PM), subcutaneous adipose tissue (SAT) and epicardial adipose tissue (EAT), and the percentage of low attenuation area (LAA%) as an index of emphysema. To elucidate the pathophysiological mechanisms underlying cachexia in COPD, we performed histological and molecular analyses of the lung, muscle and adipose tissues over time in a cigarette smoke–induced emphysema mouse model. Further, we used an in vitro culture system of differentiated adipocytes (3T3-L1) and myotubes (C2C12) to study the effects of cigarette smoke extract (CSE) on adipose–muscle interaction. Results: In patients with COPD, the areas of PM, SAT and EAT all demonstrated significant negative correlations with LAA%; notably, PM and EAT were independently associated with the extent of emphysematous changes. In the smoke-exposed murine model, adipose tissue atrophy was observed after 1 month of exposure, accompanied by increased expressions of IL-6 and IL-1β, macrophage infiltration and the upregulation of the lipolytic enzymes ATGL and HSL. The adipose atrophy had further progressed after 3 months of exposure, and the high expression of UCP1 was sustained, which suggested the browning of adipose tissue. Conversely, muscle atrophy was not evident at 1 month but became apparent after 3 months, coinciding with emphysema development. This was associated with the downregulation of the myogenic markers MyoD and Myogenin and the upregulation of the muscle degradation marker Atrogin-1. In vitro experiments revealed that CSE exposure reduced lipid droplet content and induced IL-6 and IL-1β expressions in adipocytes. Conditioned media from CSE-treated adipocytes triggered myotube atrophy and downregulated MyoD and Myogenin but upregulated Atrogin-1. Conclusions: Our findings indicate that cigarette smoke-induced adipose tissue atrophy precedes muscle wasting, and alterations in adipose tissue may contribute to muscle atrophy progression. Adipose tissue dysfunction may be implicated in the development of cachexia in patients with COPD, highlighting its potential as a therapeutic target.

Small cell lung cancer (SCLC) is a devastating disease with limited therapeutic advancements. Although SCLC has recently been classified into four molecular subtypes, subtype-specific therapies are still lacking. Here, we established 40 patient-derived SCLC organoid lines with predominant TP53 and RB1 alterations and rare targetable genetic lesions. Transcriptome profiling divided the SCLC organoids into neuroendocrine (NE)-type SCLC and non-NE-type SCLC, with the latter characterized by YAP1 or POU2F3 expression. NE-type SCLC organoids grew independent of alveolar niche factors, whereas non-NE-type SCLC organoids relied on insulin-like growth factor (IGF)-1-driven YAP1 and AP1 activation. Therapeutic targeting of IGF-1, YAP1 and AP1 effectively suppressed the growth of non-NE-type organoids. Co-knockout of TP53 and RB1 in human alveolar cells altered their lineage toward the airway epithelium-like fate and conferred IGF-1 dependency, validating the subtype-phenotype connection. Our SCLC organoid library represents a valuable resource for developing biology-based therapies and has the potential to reshape the drug discovery landscape.

Although EGFR tyrosine kinase inhibitors (EGFR-TKIs) are effective for EGFR-mutant lung adenocarcinoma (LUAD), resistance inevitably develops through diverse mechanisms, including secondary genetic mutations, amplifications and as-yet undefined processes. To comprehensively unravel the mechanisms of EGFR-TKI resistance, we establish a biobank of patient-derived EGFR-mutant lung cancer organoids, encompassing cases previously treated with EGFR-TKIs. Through comprehensive molecular profiling including single-cell analysis, here we identify a subgroup of EGFR-TKI-resistant LUAD organoids that lacks known resistance-related genetic lesions and instead exhibits a basal-shift phenotype characterized by the hybrid expression of LUAD- and squamous cell carcinoma-related genes. Prospective gene engineering demonstrates that NKX2-1 knockout induces the basal-shift transformation along with EGFR-target therapy resistance. Basal-shift LUADs frequently harbor CDKN2A/B loss and are sensitive to CDK4/6 inhibitors. Our EGFR-mutant lung cancer organoid library not only offers a valuable resource for lung cancer research but also provides insights into molecular underpinnings of EGFR-TKI resistance, facilitating the development of therapeutic strategies.

Introduction: Lung cancer is characterized by a poor prognosis and is a significant comorbidity of chronic obstructive pulmonary disease (COPD). Therefore, effective chemopreventive agents are warranted. We evaluated the effects of the cyclooxygenase-2 (COX-2) inhibitor celecoxib on the prevention of lung-carcinoma development using an intermittent smoking-induced lung-carcinoma mouse model. Additionally, we explored COX-2’s role in lipid metabolism. Methods: Male A/J mice were exposed to sham air or mainstream cigarette smoke for 20 weeks. Vehicle or celecoxib was administered via intragastric feeding once daily. Lung tissues were analyzed for tumor nodules and emphysema; the bronchoalveolar lavage fluid was collected for cell counting. COX-2 expression was measured using real-time polymerase chain reaction and western blotting; lipidomic analysis was conducted using liquid chromatography-tandem mass spectrometry. Cell proliferation and colony-forming assays were performed on LA-4 cells to assess the effects of prostaglandins and COX-2 inhibitors. Results: Intermittent smoking exposure increased lung adenomas, adenocarcinomas, and COX-2 expression. Lung adenomas were characterized by abundant COX-2-positive cells. Celecoxib reduced intermittent smoking-induced inflammation, emphysema, and cell counts in the bronchoalveolar lavage fluid and decreased the incidence of lung adenocarcinomas, whereas the total number of observed lung tumors was unchanged. Celecoxib markedly suppressed single-smoke-induced prostaglandin E2 (PGE2) production in the airway. PGE2 increased LA-4 cell viability via the EP4 receptor and promoted colony formation. Discussion: Celecoxib effectively inhibited lung-carcinoma development, inflammation, and emphysema, demonstrating the potential for chemoprevention in smokers and patients with COPD. Further studies on EP4 inhibitors for the prevention of emphysema and lung cancer are warranted.

ABT-263 (Navitoclax) is a BH3-mimetic drugs targeting anti-apoptotic B-cell lymphoma-2 (BCL-2) family proteins, including BCL-2, BCL-xL, and BCL-w, thereby inducing apoptosis. In small-cell lung cancer (SCLC) cells, the response to ABT-263 is associated with the expression of myeloid cell leukemia-1 (MCL-1) protein, however the efficacy of ABT-263 in non-small-cell lung cancer (NSCLC) has not been thoroughly evaluated. There are currently no established biomarkers for predicting the efficacy of ABT-263 treatment in NSCLC. We screened a panel of different NSCLC cell lines and found that ABT-263 inhibited cell proliferation and induced apoptosis in Calu-1, Calu-3, and BID007 cells. Inconsistent with previous reports on SCLC, low levels of MCL-1 did not predict the response to ABT-263 in NSCLC cells, however we found that intracellular levels of reactive oxygen species (ROS) in cancer cells were associated with sensitivity to ABT-263 in NSCLC cells. We also showed that increasing the level of intracellular ROS could enhance the sensitivity to ABT-263 in NSCLC cells. In summary, we propose that the intracellular levels of ROS could be used as a potential novel biomarker for predicting a response to ABT-263 in NSCLC. Furthermore, we show some evidence supporting the further assessment of ABT-263 as a new therapeutic strategy in patients with NSCLC combined with agents regulating ROS levels. We believe that our findings and follow-up studies on this matter would lead to novel diagnostic and treatment strategies in patients with NSCLC.