EGFR Tyrosine Kinase Inhibition Worsens Acute Lung Injury in Mice with Repairing Airway Epithelium

Osimertinib-induced severe bilateral pneumothorax: A case report

RATIONALE

Osimertinib is the third-generation, pyrimidine-based, irreversible epidermal growth factor receptor-tyrosine kinase inhibitor that received approval from the FDA in November 2015 and has become the standard approach in patients with advanced, epidermal growth factor receptor (EGFR) mutated non-small cell lung cancer (NSCLC), especially with brain metastases. Osimertinib is beneficial in terms of progression-free and overall survival in patients with EGFR-mutated NSCLC. However, the rarity of bilateral pneumothorax among adverse events necessitates further research on its potential fatality rate.

PATIENT CONCERNS

A 72-year-old man diagnosed with stage IV (T2NxM1) NSCLC with the 21L858R mutation of the EGFR gene received osimertinib treatment. Unfortunately, 10 weeks after osimertinib treatment, the patient developed severe interstitial lung disease and pneumothorax. Thus, osimertinib treatment was discontinued, and prednisolone (160 mg/day) and supportive treatment were administered.

DIAGNOSES

Osimertinib-induced severe interstitial lung disease and pneumothorax.

INTERVENTIONS

Osimertinib treatment was discontinued, and prednisolone (160 mg/day) and supportive treatment were administered.

OUTCOMES

The bilateral pneumothorax was difficult to correct and the patient eventually died.

LESSONS

Osimertinib-induced pneumothorax occurred approximately 10 weeks after receiving the drug and had severe cough and chest tightness as initial symptoms. In addition, the incidence of drug-induced pneumothorax increases in patients treated with osimertinib when combined with underlying respiratory diseases.

Tyrosine kinase inhibitors-associated interstitial lung disease used in non-small cell lung cancer: a pharmacovigilance analysis based on the FDA adverse event reporting system database

BACKGROUND

Interstitial lung disease (ILD) was a relatively common cause of drug-induced mortality. However, the safety profile of the whole TKIs induced ILD was largely unknown.

RESEARCH DESIGN AND METHODS

The reported cases of ILD associated with TKIs were downloaded from the FDA adverse event reporting system (FAERS) database between 1 January 2004 and 30 April 2022 to detect ILD signals by disproportionality analysis. Furthermore, the fatality rate and time to onset (TTO) of various TKIs were also calculated.

RESULTS

The median age of total 2999 reported cases was 67. The largest reported cases came from osimertinib (n = 736, 24.5%). However, gefitinib had the highest ROR of 12.47 (11.4, 13.64) and IC of 3.53 (3.23, 3.86), means the strongest association with ILD. Trametinib, vemurafenib, larotectinib, selpercatinib, and cabozantinib did not show ILD signal. The median age of dead cases was 72 (Q1:62, Q3:83), and 53.02% (n = 579) were female and 41.11% (n = 449) were male. MET group showed the highest fatality rate of 55.17% with the shortest median TTO of 21 days (Q1: 8.5, Q3: 35.5).

CONCLUSIONS

TKIs were significantly associated with ILD. More attention should be paid to female, older, MET group with shorter TTO, as their prognosis might be worse.

Interstitial lung disease risk of anaplastic lymphoma kinase tyrosine kinase inhibitor treatment of non-small cell lung cancer: a real-world pharmacovigilance study

BACKGROUND

Interstitial lung disease (ILD) is a rare but life-threatening and fatal treatment-related pneumonitis. This study investigated the association between anaplastic lymphoma kinase tyrosine kinase inhibitors (ALK-TKIs) and ILD.

RESEARCH DESIGN AND METHODS

Cases of ILD that developed after treatment with an ALK-TKI in the Food and Drug Administration' s Adverse Event Reporting System (FAERS) data were assessed. We also described the clinical features of these cases and evaluated onset time, hospitalization, life-threatening condition, and fatality rate of ILD developed after treatment with an ALK-TKI.

RESULTS

All five ALK-TKI regimens were significantly associated with ILD. The median onset time to ILD was significantly different for brigatinib, crizotinib, alectinib, lorlatinib, and ceritinib: 4.5, 25, 35.5, 54.5, and 84 days, respectively. ALK-TKI-associated ILD resulted in hospitalization in 55.77% of patients and death or life-threatening outcomes in 43.03%. The highest and lowest proportions of ILD-related fatalities were observed after crizotinib and alectinib treatment, respectively.

CONCLUSIONS

ALK-TKIs were associated with ILD; therefore, the risk of developing ILD after treatment with an ALK-TKI should be carefully considered in clinical settings.

Efficacy of crizotinib retreatment after crizotinib-related interstitial lung disease in a patient with ROS1-rearranged advanced lung adenocarcinoma: A case report and potential crizotinib retreatment strategy

Crizotinib is an oral selective small-molecular tyrosine kinase inhibitor (TKI) that suppress the activity of anaplastic lymphoma kinase (ALK) and ROS1 kinases, as well as mesenchymal-epithelial transition. The cumulative clinical trials in patients with advanced ALK- or ROS1-rearrangement NSCLC indicate that crizotinib has significant antitumor activity and a tolerable safety profile, with mild or moderate adverse events of visual disorders, diarrhea, nausea, and vomiting. As with other TKIs, however, the occurrence of crizotinib-related interstitial lung disease (crizotinib-ILD) remains a major clinical dilemma that can lead to the permanent discontinuation of TKI during cancer treatment. When there is no suitable alternative therapy for patients who develop crizotinib-ILD, some clinicians have reported successful crizotinib retreatment in cases of ALK-rearrangement NSCLC. Unfortunately, there are no specific guidelines for the treatment or retreatment of TKI-related ILD. We herein report the first successful crizotinib retreatment after crizotinib-ILD in a patient with ROS1-rearranged NSCLC, and suggest a retreatment strategy after crizotinib-ILD based on a literature review.

Epidermal Growth Factor Receptor Inhibition Is Protective in Hyperoxia-Induced Lung Injury

Aims

Studies have linked severe hyperoxia, or prolonged exposure to very high oxygen levels, with worse clinical outcomes. This study investigated the role of epidermal growth factor receptor (EGFR) in hyperoxia-induced lung injury at very high oxygen levels (>95%).

Results

Effects of severe hyperoxia (100% oxygen) were studied in mice with genetically inhibited EGFR and wild-type littermates. Despite the established role of EGFR in lung repair, EGFR inhibition led to improved survival and reduced acute lung injury, which prompted an investigation into this protective mechanism. Endothelial EGFR genetic knockout did not confer protection. EGFR inhibition led to decreased levels of cleaved caspase-3 and poly (ADP-ribosyl) polymerase (PARP) and decreased terminal dUTP nick end labeling- (TUNEL-) positive staining in alveolar epithelial cells and reduced ERK activation, which suggested reduced apoptosis in vivo. EGFR inhibition decreased hyperoxia (95%)-induced apoptosis and ERK in murine alveolar epithelial cells in vitro, and CRISPR-mediated EGFR deletion reduced hyperoxia-induced apoptosis and ERK in human alveolar epithelial cells in vitro. Innovation. This work defines a protective role of EGFR inhibition to decrease apoptosis in lung injury induced by 100% oxygen. This further characterizes the complex role of EGFR in acute lung injury and outlines a novel hyperoxia-induced cell death pathway that warrants further study.

Conclusion

In conditions of severe hyperoxia (>95% for >24 h), EGFR inhibition led to improved survival, decreased lung injury, and reduced cell death. These findings further elucidate the complex role of EGFR in acute lung injury.

Pseudomonas aeruginosa Alters Critical Lung Epithelial Cell Functions through Activation of ADAM17

Severe epithelial dysfunction is one major hallmark throughout the pathophysiological progress of bacterial pneumonia. Junctional and cellular adhesion molecules (e.g., JAMA-A, ICAM-1), cytokines (e.g., TNFα), and growth factors (e.g., TGFα), controlling proper lung barrier function and leukocyte recruitment, are proteolytically cleaved and released into the extracellular space through a disintegrin and metalloproteinase (ADAM) 17. In cell-based assays, we could show that the protein expression, maturation, and activation of ADAM17 is upregulated upon infection of lung epithelial cells with Pseudomonas aeruginosa and Exotoxin A (ExoA), without any impact of infection by Streptococcus pneumoniae. The characterization of released extracellular vesicles/exosomes and the comparison to heat-inactivated bacteria revealed that this increase occurred in a cell-associated and toxin-dependent manner. Pharmacological targeting and gene silencing of ADAM17 showed that its activation during infection with Pseudomonas aeruginosa was critical for the cleavage of junctional adhesion molecule A (JAM-A) and epithelial cell survival, both modulating barrier integrity, epithelial regeneration, leukocyte adhesion and transepithelial migration. Thus, site-specific targeting of ADAM17 or blockage of the activating toxins may constitute a novel anti-infective therapeutic option in Pseudomonas aeruginosa lung infection preventing severe epithelial and organ dysfunctions and stimulating future translational studies.

Targeting the EGFR-ERK axis using the compatible solute ectoine to stabilize CFTR mutant F508del

Mutations in the CFTR gene lead to cystic fibrosis, a genetic disease associated with chronic infection and inflammation and ultimately respiratory failure. The most common CF-causing mutation is F508del and CFTR modulators (correctors and potentiators) are being developed to rescue its trafficking and activity defects. However, there are currently no modulators that stabilize the rescued membrane F508del-CFTR which is endocytosed and quickly degraded resulting in a shorter half-life than wild-type (WT). We previously reported that the extracellular signal-regulated kinase (ERK) MAPK pathway is involved in CFTR degradation upon cigarette smoke exposure. Interestingly, we found that ERK phosphorylation was increased in CF human bronchial epithelial (HBE) cells (CF-HBE41o- and primary CF-HBE) compared to non-CF controls, and this was likely due to signaling by the epidermal growth factor receptor (EGFR). EGFR can be activated by several ligands, and we provide evidence that amphiregulin (AREG) is important for activating this signaling axis in CF. The natural osmolyte ectoine stabilizes membrane macromolecules. We show that ectoine decreases ERK phosphorylation, increases the half-life of rescued CFTR, and increases CFTR-mediated chloride transport in combination with the CFTR corrector VX-661. Additionally, ectoine reduces production of AREG and interleukin-8 by CF primary bronchial epithelial cells. In conclusion, EGFR-ERK signaling negatively regulates CFTR and is hyperactive in CF, and targeting this axis with ectoine may prove beneficial for CF patients.

Design, synthesis and structure-activity relationship studies of 4-indole-2-arylaminopyrimidine derivatives as anti-inflammatory agents for acute lung injury

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS), a clinically high mortality disease, has not been effectively treated till now, and the development of anti-acute lung injury drugs is imminent. Acute lung injury was efficiently treated by inhibiting the cascade of inflammation, and reducing the inflammatory response in the lung. A series of novel compounds with highly efficient inhibiting the expression of inflammatory factors were designed by using 4-indolyl-2-aminopyrimidine as the core skeleton. Totally eleven 4-indolyl-2-arylaminopyrimidine derivatives were designed and synthesized. As well, the related anti-ALI activity of these compounds was evaluated. Compounds 6c and 6h showed a superior activity among these compounds, and the inhibition rate of IL-6 and IL-8 release ranged from 62% to 77%, and from 65% to 72%, respectively. Furthermore, most of compounds had no significant cytotoxicity in vitro. The infiltration of inflammatory cells into lung tissue significantly reduced by using compound 6h (20 mg/kg) in the ALI mice model, which achieved the effect of protecting lung tissue and improving ALI. In addition, the inflammatory response was inhibited by using compound 6h through inhibiting phosphorylation of p-38 and ERK in MAPK signaling pathway, and resulted in protective effect on ALI. These data indicated that compound 6h showed good anti-inflammatory activity in vitro and in vivo, which was expected to become a leading compound for the treatment of ALI.

A Study Based on Metabolomics, Network Pharmacology, and Experimental Verification to Explore the Mechanism of Qinbaiqingfei Concentrated Pills in the treatment of Mycoplasma Pneumonia

Qinbaiqingfei concentrated pills (QB) are a commonly used medicine for the treatment of mycoplasma pneumonia in China, and the mechanism of action of QB needs to be studied further. Therefore, we use a combination of metabolomics and network pharmacology to clarify the mechanism of QB. Nontarget metabolomics studies were performed on rat serum, urine, and lung tissues, and 56 therapeutic biomarkers were found. Subsequently, the components of QB absorbed into the blood and lung tissues were clarified, and based on this finding, the core target of network pharmacology was predicted. The enrichment analysis of biomarkers–genes finally confirmed their close relationship with the NF-κB signaling pathway. By western blotting expression of the proteins in the lung tissue–related signaling pathways, it is finally confirmed that QB inhibits the NF-κB signaling pathway through SIRT1, IL-10 and MMP9, CTNNB1, EGFR, and other targets. It plays a role in regulating immunity, regulating metabolism, and treating diseases.

RASAL2 Confers Collateral MEK/EGFR Dependency in Chemoresistant Triple-Negative Breast Cancer

PURPOSE

While chemotherapy remains the standard treatment for triple-negative breast cancer (TNBC), identifying and managing chemoresistant tumors has proven elusive. We sought to discover hallmarks and therapeutically actionable features of refractory TNBC through molecular analysis of primary chemoresistant TNBC specimens.

EXPERIMENTAL DESIGN

We performed transcriptional profiling of tumors from a phase II clinical trial of platinum chemotherapy for advanced TNBC (TBCRC-009), revealing a gene expression signature that identified de novo chemorefractory tumors. We then employed pharmacogenomic data mining, proteomic and other molecular studies to define the therapeutic vulnerabilities of these tumors.

RESULTS

We reveal the RAS-GTPase-activating protein (RAS-GAP) RASAL2 as an upregulated factor that mediates chemotherapy resistance but also an exquisite collateral sensitivity to combination MAP kinase kinase (MEK1/2) and EGFR inhibitors in TNBC. Mechanistically, RASAL2 GAP activity is required to confer kinase inhibitor sensitivity, as RASAL2-high TNBCs sustain basal RAS activity through suppression of negative feedback regulators SPRY1/2, together with EGFR upregulation. Consequently, RASAL2 expression results in failed feedback compensation upon co-inhibition of MEK1/2 and EGFR that induces synergistic apoptosis in vitro and in vivo. In patients with TNBC, high RASAL2 levels predict clinical chemotherapy response and long-term outcomes, and are associated via direct transcriptional regulation with activated oncogenic Yes-Associated Protein (YAP). Accordingly, chemorefractory patient-derived TNBC models exhibit YAP activation, high RASAL2 expression, and tumor regression in response to MEK/EGFR inhibitor combinations despite well-tolerated intermittent dosing.

CONCLUSIONS

These findings identify RASAL2 as a mediator of TNBC chemoresistance that rewires MAPK feedback and cross-talk to confer profound collateral sensitivity to combination MEK1/2 and EGFR inhibitors.

Overlap time is an independent risk factor of radiation pneumonitis for patients treated with simultaneous EGFR-TKI and thoracic radiotherapy

Background

The exact rate and relevant risk factors of radiation pneumonitis (RP) for non-small-cell cancer (NSCLC) patients treated with the combination of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) and thoracic radiotherapy have not been reported. Thus, this study aimed to investigate the rate and risk factors of RP for EGFR-positive NSCLC patients simultaneously treated with first-generation EGFR-TKI and TRT.

Patients and methods

We retrospectively evaluated NSCLC patients simultaneously treated with first-generation EGFR-TKI and thoracic radiotherapy between January 2012 and December 2019 at Shandong Cancer Hospital and Institute, Shandong, China. RP was diagnosed via computed tomography and was classified according to the Common Terminology Criteria for Adverse Events v5.0. The risk factors of RP were identified using uni- and multivariate analyses.

Results

Of the 67 patients included, 44.78% (30/67) developed grade ≥ 2 RP. Grade ≥ 2 RP occurred within a median of 3.48 (range 1.07–13.6) months. The EGFR-TKI icotinib, ipsilateral lung V30 > 34%, and overlap time of > 20 days between EGFR-TKI and thoracic radiotherapy were identified to be independent predictive factors of grade ≥ 2 RP.

Conclusions

Grade ≥ 2 RP is highly frequent in NSCLC patients simultaneous treated with first-generation EGFR-TKI and thoracic radiotherapy. Icotinib, ipsilateral lung V30 ≤ 34%, and overlap time of ≤ 20 days for EGFR-TKI and thoracic radiotherapy will be helpful to lower the risk of RP in these patients. The addition of thoracic radiotherapy should be cautious, and the treatment strategies can be optimized to reduce the rate of RP for patients treat with simultaneous EGFR-TKI and thoracic radiotherapy.

Molecular and Clinical Features of EGFR-TKI-Associated Lung Injury

The tyrosine kinase activity of epidermal growth factor receptors (EGFRs) plays critical roles in cell proliferation, regeneration, tumorigenesis, and anticancer resistance. Non-small-cell lung cancer patients who responded to EGFR-tyrosine kinase inhibitors (EGFR-TKIs) and obtained survival benefits had somatic EGFR mutations. EGFR-TKI-related adverse events (AEs) are usually tolerable and manageable, although serious AEs, including lung injury (specifically, interstitial lung disease (ILD), causing 58% of EGFR-TKI treatment-related deaths), occur infrequently. The etiopathogenesis of EGFR-TKI-induced ILD remains unknown. Risk factors, such as tobacco exposure, pre-existing lung fibrosis, chronic obstructive pulmonary disease, and poor performance status, indicate that lung inflammatory circumstances may worsen with EGFR-TKI treatment because of impaired epithelial healing of lung injuries. There is limited evidence from preclinical and clinical studies of the mechanisms underlying EGFR-TKI-induced ILD in the available literature. Herein, we evaluated the relationship between EGFR-TKIs and AEs, especially ILD. Recent reports on mechanisms inducing lung injury or resistance in cytokine-rich circumstances were reviewed. We discussed the relevance of cytotoxic agents or immunotherapeutic agents in combination with EGFR-TKIs as a potential mechanism of EGFR-TKI-related lung injury and reviewed recent developments in diagnostics and therapeutics that facilitate recovery from lung injury or overcoming resistance to anti-EGFR treatment.

Acute Interstitial Lung Disease Induced by Rechallenge with Ceritinib

A 40-year-old Japanese man with advanced pulmonary adenocarcinoma harboring anaplastic lymphoma kinase (ALK)-rearranged was administered the selective ALK inhibitor ceritinib as a third-line treatment and continued treatment for nine months. After fourth-line treatment, we performed rechallenge with ceritinib as a fifth-line treatment. On day 54 after rechallenge, the patient developed acutely deteriorating dyspnea. Chest computed tomography showed extensive ground-glass opacities. We diagnosed him with ceritinib-induced interstitial lung disease (ILD) and initiated methylprednisolone pulse therapy. To our knowledge, this is the first report of ceritinib-induced ILD in a Japanese patient. Since it may newly emerge with rechallenge therapy, close attention is necessary.

Using Bronchoalveolar Lavage to Evaluate Changes in Pulmonary Diseases

Bronchoalveolar lavage (BAL) is a procedure that can be used to collect samples from human and animal lungs to efficiently evaluate the immune response and the potentially pathological changes by examining both the compositions of cells and fluid from lavage. There are observable changes including inflammatory response in human and animal lungs exposed to environmental exposures such as toxic chemicals and microorganisms, or under pathophysiological conditions in respiratory system. The profile of inflammatory cells in BAL provides a qualitative description of inflammatory response, and the secretion in BAL fluid contains secreted proteins of inflammatory mediators and albumin as a quantitative measurement of inflammation and tissue injury in the lungs. Mouse is the most common model system being used for pulmonary disease-related research. A consistent experimental approach on how to lavage mouse lungs and collect samples from mouse lungs is important for a reproducible evaluation of pathological and physiological changes in mouse lung especially for the analysis of inflammation.

Molecular hydrogen attenuates gefitinib-induced exacerbation of naphthalene-evoked acute lung injury through a reduction in oxidative stress and inflammation

Although inhibition of epidermal growth factor receptor (EGFR)-mediated cell signaling by the EGFR tyrosine kinase inhibitor gefitinib is highly effective against advanced non-small cell lung cancer, this drug might promote severe acute interstitial pneumonia. We previously reported that molecular hydrogen (H₂) acts as a therapeutic and preventive anti-oxidant. Here, we show that treatment with H₂ effectively protects the lungs of mice from severe damage caused by oral administration of gefitinib after intraperitoneal injection of naphthalene, the toxicity of which is related to oxidative stress. Drinking H₂-rich water ad libitum mitigated naphthalene/gefitinib-induced weight loss and significantly improved survival, which was associated with a decrease in lung inflammation and inflammatory cytokines in the bronchoalveolar lavage fluid. Naphthalene decreased glutathione in the lung, increased malondialdehyde in the plasma, and increased 4-hydroxy-2-nonenal production in airway cells, all of which were mitigated by H₂-rich water, indicating that the H₂-rich water reverses cellular damage to the bronchial wall caused by oxidative stress. Finally, treatment with H₂ did not interfere with the anti-tumor effects of gefitinib on a lung cancer cell line in vitro or on tumor-bearing mice in vivo. These results indicate that H₂-rich water has the potential to improve quality of life during gefitinib therapy by mitigating lung injury without impairing anti-tumor activity.

Interstitial pneumonia suspected during regorafenib administration and exacerbated by subsequent therapy with lenvatinib for unresectable hepatocellular carcinoma

Recently, three tyrosine kinase inhibitors (TKIs) have become available for treatment of unresectable hepatocellular carcinoma (HCC). We herein report a case of a 59-year-old man with interstitial pneumonia that was suspected during regorafenib administration and was exacerbated by subsequent lenvatinib treatment for advanced HCC. After sorafenib was discontinued due to progressive HCC, regorafenib treatment was started. Progressive HCC was again noted and reticular shadows were suspected in both lower lung fields at 2 months after starting regorafenib administration. Subsequent treatment with lenvatinib obtained a partial response for HCC, but the reticular shadows became marked and dyspnea on effort emerged, followed by hypoxemia and an increased Krebs von den Lungen-6 (KL-6) value. Because we suspected acute interstitial pneumonia, due to these TKIs, intravenous pulse steroid therapy was started immediately after discontinuing lenvatinib. Within 1 week after starting steroid therapy, the patient's respiratory condition and hypoxemia gradually began improving. No previous case of pulmonary interstitial changes that appeared in association with regorafenib administration for HCC and that were exacerbated by subsequent treatment with lenvatinib has been reported. This case emphasizes that it is necessary to observe the patient's respiratory condition and to perform imaging examinations to monitor for adverse events during TKI treatment.

The therapeutic effects of bone marrow-derived mesenchymal stromal cells in the acute lung injury induced by sulfur mustard

Background

Sulfur mustard (SM) is a notorious chemical warfare agent that can cause severe acute lung injury (ALI), in addition to other lesions. Currently, effective medical countermeasures for SM are lacking. Bone marrow-derived mesenchymal stromal cells (BMSCs) possess self-renewal and multipotent differentiation capacity. BMSCs can also migrate to inflammation and injury sites and exert anti-inflammatory and tissue repair functions. Here, we report the curative effect of BMSCs on SM-induced ALI in a mouse model.

Methods

Mice BMSCs were injected into mice via the tail vein 24 h after SM exposure. The distribution of BMSCs in mice was detected by fluorescence imaging. The therapeutic potential of BMSCs was evaluated by the calculating survival rate. The effects of BMSCs on lung tissue injury and repair assessment were examined by staining with H&E and measuring the lung wet/dry weight ratio, BALF protein level, and respiratory function. The effects of BMSCs on the infiltration and phenotypic alteration of inflammatory cells were analyzed by immunohistochemistry and flow cytometry. The levels of chemokines and inflammatory cytokines were examined using the Luminex Performance Assay and ELISA. RNA interference, western blotting, and ELISA were applied to explore the role of the TLR4 signaling pathway in the anti-inflammatory effects of BMSCs. The extent of tissue repair was analyzed by ELISA, western blotting, and immunohistochemistry.

Results

Fluorescence imaging indicated that the lung is the major target organ of BMSCs after injection. The injection of BMSCs significantly improved the survival rate (p < 0.05), respiratory function, and related lung damage indexes (wet/dry weight ratio, total proteins in BALF, etc.) in mice. BMSC administration also reduced the level of pro-inflammatory cytokines, chemokines, and inflammatory cell infiltration, as well as affected the balances of M1/M2 and Th17/Treg. Furthermore, solid evidence regarding the effects of BMSCs on the increased secretion of various growth factors, the differentiation of alveolar epithelial cells, and the enhancement of cell barrier functions was also observed.

Conclusion

BMSCs displayed protective effects against SM-induced ALI by alleviating inflammation and promoting tissue repair. The present study provides a strong experimental basis in a mouse model and suggests possible application for future cell therapy.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1189-x) contains supplementary material, which is available to authorized users.

Alveolar type 2 progenitor cells for lung injury repair

Alveolar type 2 progenitor cells (AT2) seem closest to clinical translation, specifying the evidence that AT2 may satisfactorily control the immune response to decrease lung injury by stabilizing host immune-competence and a classic and crucial resource for lung regeneration and repair. AT2 establish potential in benefiting injured lungs. However, significant discrepancies linger in our understanding vis-à-vis the mechanisms for AT2 as a regime for stem cell therapy as well as essential guiding information for clinical trials, including effectiveness in appropriate pre-clinical models, safety, mostly specifications for divergent lung injury patients. These important gaps shall be systematically investigated prior to the vast therapeutic perspective of AT2 cells for pulmonary diseases can be considered. This review focused on AT2 cells homeostasis, pathophysiological changes in the pathogenesis of lung injury, physiological function of AT2 cells, apoptosis of AT2 cells in lung diseases, the role of AT2 cells in repairing processes after lung injury, mechanism of AT2 cells activation promote repairing processes after lung injury, and potential therapy of lung disease by utilizing the AT2 progenitor cells. The advancement remains to causally connect the molecular and cellular alteration of AT2 cells to lung injury and repair. Conclusively, it is identified that AT2 cells can convert into AT1 cells; but, the comprehensive cellular mechanisms involved in this transition are unrevealed. Further investigation is mandatory to determine new strategies to prevent lung injury.

Impact of Radiotherapy Concurrent with Anti-PD-1 Therapy on the Lung Tissue of Tumor-Bearing Mice

Pneumonitis is a common adverse effect found in non-small cell lung cancer patients after radiotherapy or immune checkpoint inhibitor treatment. We investigated the effects of these two therapies, combined, in the lung tissue of an orthotopic tumor-bearing mouse model. The mice received an 8 Gy dose three times with or without 200 µg anti-programmed death-1 (anti-PD-1) antibody intraperitoneal injection every three days. Lung tissues were H&E stained to determine histological changes. The serum levels of cytokines, such as interferon-γ, tumor necrosis factor and interleukin-5, were detected by cytometric bead array. The neutrophil infiltration was evaluated by immunohistochemical staining for myeloperoxidase. The lung injury score was higher in the treated groups than the control group, especially in the combined treatment group, in which the proportion of neutrophils in lung tissues was significantly higher compared to any other groups. Similarly, the CD4/CD8 ratio of the lung tissues in the combined treatment group, as well as the serum levels of interferon-γ, tumor necrosis factor and interleukin-5, were significantly higher than the other groups. These findings indicate that radiation combined with anti-PD-1 treatment leads to more severe lung injury in the orthotopic tumor-bearing mouse model, accompanied by increased neutrophil infiltration and increased inflammatory response.

Successful re-introduction of alectinib after inducing interstitial lung disease in a patient with lung cancer

Alectinib is a member of the family of anaplastic lymphoma kinase inhibitors. This agent is effective in the treatment of advanced anaplastic lymphoma kinase-positive non-small cell lung cancer and has excellent blood–brain barrier penetrability. It is generally well tolerated; however, significant toxicities such as interstitial lung disease have been reported. We present herein an instance of interstitial lung disease four weeks into alectinib treatment. Alectinib was held, and the patient showed clinical and radiographic improvement of her interstitial lung disease. Alectinib was then resumed at half dosage without further complications. Prompt recognition of adverse reactions to this targeted agent is paramount. Cessation of therapy may be needed on a case-to-case basis. However, as our case highlights, safe re-introduction of alectinib can be accomplished in some cases.

Heparin-binding EGF-like growth factor attenuates lung inflammation and injury in a murine model of pulmonary emphysema

Pulmonary inflammation and progressive lung destruction are the major causes of chronic obstructive pulmonary disease (COPD), resulting in emphysema and irreversible pulmonary dysfunction. Heparin-binding EGF-like growth factor (HB-EGF), is known to play a protective role in the process of various inflammatory diseases. However, its effect on COPD is poorly understood. This study was designed to determine the effect of HB-EGF on lung inflammation and injury in a murine model of pulmonary emphysema. HB-EGF promoted percent survival and body weight, attenuated lung injury, inflammatory cells, and cytokines infiltration, and prevented lung function decline. Additionally, treatment of rHB-EGF suppressed the nuclear translocation of nuclear factor κB (NF-κB)/p65, decreased TUNEL-positive cells and the expression of caspase 3, and increased the expression of PCNA, HB-EGF, and EGF receptor (EGFR). We conclude that HB-EGF attenuates lung inflammation and injury, probably through the activation of EGFR, followed by suppression of NF-ΚB signalling, promotion of cell proliferation, and inhibition of apoptosis.

Linking tyrosine kinase inhibitor-mediated inflammation with normal epithelial cell homeostasis and tumor therapeutic responses

Receptor tyrosine kinases (RTKs) bearing oncogenic mutations in EGFR, ALK and ROS1 occur in a significant subset of lung adenocarcinomas. Tyrosine kinase inhibitors (TKIs) targeting tumor cells dependent on these oncogenic RTKs yield tumor shrinkage, but also a variety of adverse events. Skin toxicities, hematological deficiencies, nausea, vomiting, diarrhea, and headache are among the most common, with more acute and often fatal side effects such as liver failure and interstitial lung disease (ILD) occurring less frequently. In normal epithelia, RTKs regulate tissue homeostasis. For example, EGFR maintains keratinocyte homeostasis while MET regulates processes associated with tissue remodeling. Previous studies suggest that the acneiform rash occurring in response to EGFR inhibition is a part of an inflammatory response driven by pronounced cytokine and chemokine release and recruitment of distinct immune cell populations. Mechanistically, blockade of EGFR causes a Type I interferon (IFN) response within keratinocytes and in carcinoma cells driven by this RTK. This innate immune response within the tumor microenvironment (TME) involves increased antigen presentation and effector T cell recruitment that may participate in therapy response. This TKI-mediated release of inflammatory suppression represents a novel tumor cell vulnerability that may be exploited by combining TKIs with immune-oncology (IO) agents that rely on T-cell inflammation for efficacy. However, early clinical data indicate that combination therapies enhance the frequency and magnitude of the more acute adverse events, especially pneumonitis, hepatitis, and pulmonary fibrosis. Further preclinical studies to understand TKI mediated inflammation and crosstalk between normal epithelial cells, cancer cells, and the TME are necessary to improve treatment regimens for patients with RTK-driven carcinomas.

Identification of differentially expressed genes and signaling pathways using bioinformatics in interstitial lung disease due to tyrosine kinase inhibitors targeting the epidermal growth factor receptor

Interstitial lung disease (ILD) is a rare but lethal adverse effect of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) treatment. The specific mechanism of this disease is not fully understood. To systematically analyze genes associated with EGFR-TKI induced ILD, gene data of EGFR-TKI induced ILD were extracted initially using text mining, and then the intersection between genes from text mining and Gene Expression Omnibus (GEO) dataset was taken for further protein-protein interaction (PPI) analysis using String-bd database. Go ontology (GO) and pathway enrichment analysis was also conducted based on Database of Annotation, Visualization and Integrated Discovery (DAVID) platform. The PPI network generated by STRING was visualized by Cytoscape, and the topology scores, functional regions and gene annotations were analyzed using plugins of CytoNCA, molecular complex detection (MCODE) and ClueGo. 37 genes were identified as EGFR-TKI induced ILD related. Gene enrichment analysis yield 18 enriched GO terms and 12 associated pathways. A PPI network that included 199 interactions for a total of 35 genes was constructed. Ten genes were selected as hub genes using CytoNCA plugin, and four highly connected clusters were identified using MCODE plugin. GO and pathway annotation analysis for the cluster one revealed that five genes were associated with either response to dexamethasone or with lung fibrosis, including CTGF, CCL2, IGF1, EGFR and ICAM1. Our data might be useful to reveal the pathological mechanisms of EGFR-TKI induced ILD and provide evidence for the diagnosis and treatment in the future.

Systematic review and meta-analysis of selected toxicities of approved ALK inhibitors in metastatic non-small cell lung cancer

Introduction

Anaplastic lymphoma kinase (ALK) inhibitors are the mainstay treatment for patients with non-small cell lung carcinoma (NSCLC) harboring a rearrangement of the ALK gene or the ROS1 oncogenes. With the recent publication of pivotal trials leading to the approval of these compounds in different indications, their toxicity profile warrants an update.

Materials and Methods

A systematic literature search was performed in July 2017. Studies evaluating US FDA approved doses of one of the following ALK inhibitors: Crizotinib, Ceritinib, Alectinib or Brigatinib as monotherapy were included. Data were analyzed using random effects meta-analysis for absolute risks (AR), study heterogeneity, publication bias and differences among treatments.

Results

Fifteen trials with a total of 2,005 patients with evaluable toxicity data were included in this report. There was significant heterogeneity amongst different studies. The pooled AR of death and severe adverse events were 0.5% and 34.5%, respectively. Grade 3/4 nausea, vomiting, diarrhea, and constipation were uncommon: 2.6%, 2.5%, 2.7%, 1.2%, respectively.

Conclusions

ALK inhibitors have an acceptable safety profile with a low risk of treatment-related deaths. Important differences in toxicity profile were detected amongst the different drugs.

Inhibition of epidermal growth factor receptor attenuates LPS-induced inflammation and acute lung injury in rats

Acute lung injury (ALI) and its severe form acute respiratory distress syndrome remain the leading cause of morbidity and mortality in intensive care units. Inhibition of epidermal growth factor receptor (EGFR) has been found to be able to reduce inflammatory response. However, it is still unclear whether EGFR inhibition can prevent ALI. This study aimed to validate the EGFR's role in ALI and investigated the effects of EGFR inhibition on lipopolysaccharides (LPS)-induced ALI in rats. In vitro, both pharmacological inhibitors (AG1478 and 451) and si-RNA silencing of EGFR significantly inhibited LPS-induced EGFR signaling activation and inflammatory response in human lung epithelial cells or macrophages. Mechanistically, LPS induced EGFR activation via TLR4 and c-Src signaling. In vivo, rat model with ALI induced by intratracheal instillation of LPS was treated by oral administration of AG1478 and 451. It was observed that AG1478 and 451 blocked the activation of EGFR signaling in lung tissue and reduced the LPS-induced infiltration of inflammatory cells, inflammatory gene expression, and lung injuries. This study demonstrates that TLR4/c-Src-dependent EGFR signaling plays an important role in LPS-induced ALI, and that EGFR may be a potential target in treating ALI.

Cytokine Profiles of Severe Influenza Virus-Related Complications in Children

Rationale

Effective immunomodulatory therapies for children with life-threatening “cytokine storm” triggered by acute influenza infection are lacking. Understanding the immune profiles of children progressing to severe lung injury and/or septic shock could provide insight into pathogenesis.

Objectives

To compare the endotracheal and serum cytokine profiles of children with influenza-related critical illness and to identify their associations with severe influenza-associated complications.

Methods

Children with influenza-related critical illness were enrolled across 32 hospitals in development (N = 171) and validation (N = 73) cohorts (December 2008 through May 2016). Concentrations of 42 cytokines were measured in serum and endotracheal samples and clustered into modules of covarying cytokines. Relative concentrations of cytokines and cytokine modules were tested for associations with acute lung injury (ALI), shock requiring vasopressors, and death/ECMO.

Measurements and main results

Modules of covarying cytokines were more significantly associated with disease severity than individual cytokines. In the development cohort, increased levels of a serum module containing IL6, IL8, IL10, IP10, GCSF, MCP1, and MIP1α [shock odds ratio (OR) = 3.37, family-wise error rate (FWER) p < 10⁻⁴], and decreased levels of a module containing EGF, FGF2, SCD40L, and PAI-1 (shock OR = 0.43, FWER p = 0.002), were both associated with ALI, shock, and death-ECMO independent of age and bacterial coinfection. Both of these associations were confirmed in the validation cohort. Endotracheal and serum cytokine associations differed markedly and were differentially associated with clinical outcomes.

Conclusion

We identified strong positive and negative associations of cytokine modules with the most severe influenza-related complications in children, providing new insights into the pathogenesis of influenza-related critical illness in children. Effective therapies may need to target mediators of both inflammation and repair.

Depletion of club cells attenuates bleomycin-induced lung injury and fibrosis in mice

Background

The role of bronchiolar epithelial cells in the pathogenesis of pulmonary fibrosis has not been clarified. We previously demonstrated DNA damage in murine bronchioles in the early stages of bleomycin-induced pulmonary fibrosis that subsequently extended to alveolar cells at the advanced stages of the disease. Club cells are progenitor cells for bronchioles and are known to play protective roles against lung inflammation and damage. The aim of the present study was to elucidate the role of club cells in the development of pulmonary fibrosis.

Methods

C57BL/6 J mice received naphthalene intraperitoneally on day −2 to deplete club cells and were given intratracheal bleomycin or a vehicle on day 0. Lung tissues were obtained on days 1, 7, and 14, and bronchoalveolar lavage was performed on day 14. Bronchiolar epithelial cells sampled by laser capture microdissection were analyzed by gene expression microarray analysis on day 14.

Results

Club cell depletion induced by naphthalene protected mice from bleomycin-induced lung injury and fibrosis. Bleomycin-triggered bronchiolar TGF-β1 expression was reduced. Gene expression microarray analysis revealed that genes associated with inflammatory response and chemokine activity were downregulated in the bleomycin-injured bronchiolar epithelium with club cell injury compared to that in bronchiolar epithelium without cell injury.

Conclusions

Club cells are involved in the development of lung injury and fibrosis.

Treatment with a programmed cell death-1-specific antibody has little effect on afatinib- and naphthalene-induced acute pneumonitis in mice

Although several antibodies developed to target programmed cell death-1 (PD-1) and its ligand (PD-L1) have demonstrated great promise for the treatment of non-small cell lung cancer (NSCLC), and other malignancies, these therapeutic antibodies can cause pneumonitis. Furthermore, epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI)-induced pneumonitis was reported after treatment with anti PD-1 antibodies. We previously demonstrated that mice with naphthalene-induced airway epithelial injury developed severe gefitinib-induced pneumonitis through a neutrophil-dependent mechanism. The present study aimed to investigate whether treatment with afatinib, an EGFR-TKI that effectively targets EGFR mutation-positive NSCLC, and anti PD-1 antibodies induces pneumonitis in mice. C57BL/6J mice were treated intraperitoneally with naphthalene (200 mg/kg) on day 0. Afatinib (20 mg/kg) was administered orally on days -1 to 13. An anti-PD-1 antibody (0.2 mg/mice) was also administered intraperitoneally every 3 days from day 1 until day 13. The bronchoalveolar lavage fluid (BALF) and lung tissues were sampled on day 14. As observed previously with gefitinib, afatinib significantly increased the severity of histopathologic findings and the level of protein in BALF on day 14, compared to treatment with naphthalene alone. A combined anti-PD-1 antibody and afatinib treatment after naphthalene administration had yielded the same histopathological grade of lung inflammation as did afatinib treatment alone. Our results suggest that anti-PD-1 antibody treatment has little effect on afatinib-induced lung injury.

Meta-analysis of the incidence and risks of interstitial lung disease and QTc prolongation in non-small-cell lung cancer patients treated with ALK inhibitors

BACKGROUND

To conduct a systematic review and meta-analysis to assess the overall incidence and risk of interstitial lung disease (ILD) and QTc prolongation associated with anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitors (-TKIs) in non-small-cell lung cancer (NSCLC) patients.

RESULTS

A total of 1,770 patients from 8 clinical trials were included. The incidences of high-grade ILD and QTc prolongation was 2.5% (95% CI 1.7-3.6%), and 2.8% (95% CI 1.8-4.3%), respectively. Meta-analysis demonstrated that the use of ALK-TKIs in NSCLC patients significantly increased the risk of developing high-grade ILD (Peto OR, 3.27, 95%CI: 1.18-9.08, p = 0.023) and QTc prolongation (Peto OR 7.51, 95% CI, 2.16-26.15; p = 0.002) in comparison with chemotherapy alone.

MATERIALS AND METHODS

A systematic literature search was performed to identify related citations up to January 31, 2017. Data were extracted, and summary incidence rates, Peto odds ratios (Peto ORs), and 95% confidence intervals (CIs) were calculated.

CONCLUSIONS

The use of ALK-TKIs significantly increases the risk of developing high-grade ILD and QTc prolongation in lung cancer patients. Clinicians should pay attention to the risks of severe ILD and QTc prolongation with the administration of these drugs.

Amphiregulin suppresses epithelial cell apoptosis in lipopolysaccharide-induced lung injury in mice

BACKGROUND AND OBJECTIVE

As a member of the epidermal growth factor family, amphiregulin contributes to the regulation of cell proliferation. Amphiregulin was reported to be upregulated in damaged lung tissues in patients with chronic obstructive pulmonary disease and asthma and in lung epithelial cells in a ventilator-associated lung injury model. In this study, we investigated the effect of amphiregulin on lipopolysaccharide (LPS)-induced acute lung injury in mice.

METHODS

Acute lung injury was induced by intranasal instillation of LPS in female C57BL/6 mice, and the mice were given intraperitoneal injections of recombinant amphiregulin or phosphate-buffered saline 6 and 0.5 h before and 3 h after LPS instillation. The effect of amphiregulin on apoptosis and apoptotic pathways in a murine lung alveolar type II epithelial cell line (LA-4 cells) were examined using flow cytometry and western blotting, respectively.

RESULTS

Recombinant amphiregulin suppressed epithelial cell apoptosis in LPS-induced lung injury in mice. Western blotting revealed that amphiregulin suppressed epithelial cell apoptosis by inhibiting caspase-8 activity.

CONCLUSION

Amphiregulin signaling may be a therapeutic target for LPS-induced lung injury treatment through its prevention of epithelial cell apoptosis.

Successful alectinib treatment after crizotinib-induced interstitial lung disease

A 70‐year‐old woman with lung adenocarcinoma, harbouring anaplastic lymphoma kinase gene rearrangement, was treated with crizotinib as third‐line chemotherapy. After 2 months, crizotinib was discontinued because of the development of crizotinib‐induced interstitial lung disease (ILD). Steroid treatment was then introduced and tapered off. Following complete resolution of the interstitial shadow, cytotoxic chemotherapy was initiated, and continued for over 2 years, until new intrapulmonary lesions developed. Although there was a risk of drug‐induced interstitial pneumonia, alectinib was initiated as the fifth‐line therapy, without steroid supplementation, as there was no alternative treatment. No recurrence of ILD was noted at 10 months. To our knowledge, this is the first report of successful alectinib treatment after the development of crizotinib‐induced ILD without the use of prednisolone.

Implementation of modern therapy approaches and research for non-small cell lung cancer in Japan

The genetic backgrounds of the Japanese (or Asians) are, at least in part, different from those of Caucasians. It is necessary to recognize this difference to develop medicine that is both optimized and individualized. In particular, the consideration of ethnic differences is becoming increasingly important for lung cancer medicine. Japanese clinical practice guidelines indicate that some clinical biomarkers, such as epidermal growth factor receptor gene mutations, echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion gene and uridine diphosphate glucuronosyltransferase genotypes should be determined in appropriate lung cancer patients. At the present time, tests for these biomarkers are covered by the Japanese national health-care programme, as is treatment with certain targeted drugs and cytotoxic agents. Therefore, most patients with lung cancer in Japan receive these tests as part of daily practice if their performance status and organ function are judged to be eligible. In addition, ethnic differences in bone marrow toxicity caused by cytotoxic drugs are reflected in treatment choice, and the requirements for the development of treatment modalities suitable for rare targeted populations are also increasing. To meet these requirements, many collaborative groups in Japan that have improved their infrastructure for investigator-initiated trials and conducted important activities need to provide further optimal treatment modalities for Japanese and Asian patients with lung cancer. Here, the characteristics of lung cancer in Japanese patients, general aspects of medical treatment and the care system in Japan, and representative studies on lung cancer in Japan are reviewed.

SYSTEM-WIDE MAPPING OF ACTIVATED CIRCUITRY IN EXPERIMENTAL SYSTEMIC INFLAMMATORY RESPONSE SYNDROME

Sepsis-induced multiple organ dysfunction syndrome (MODS) is a major cause of morbidity and mortality in critically ill patients and remains impervious to most therapeutic interventions. We utilized a clinically relevant murine model of systemic inflammatory response syndrome (SIRS) during early MODS induced by ventilator-associated pneumonia to systematically delineate pathways dysregulated in lung, liver, and kidney. We focused on processes commonly activated across at-risk organs and constructed an SIRS-associated network based on connectivity among the gene members of these functionally coherent pathways. Our analyses led to the identification of several putative drivers of early MODS whose expression was regulated by epidermal growth factor receptor. Our unbiased, integrative method is a promising approach to unravel mechanisms in system-wide disorders afflicting multiple compartments such as sepsis-induced MODS, and identify putative therapeutic targets.

Influenza induces IL-8 and GM-CSF secretion by human alveolar epithelial cells through HGF/c-Met and TGF-α/EGFR signaling

The most severe complication of influenza is viral pneumonia, which can lead to the acute respiratory distress syndrome. Alveolar epithelial cells (AECs) are the first cells that influenza virus encounters upon entering the alveolus. Infected epithelial cells produce cytokines that attract and activate neutrophils and macrophages, which in turn induce damage to the epithelial-endothelial barrier. Hepatocyte growth factor (HGF)/c-Met and transforming growth factor-α (TGF-α)/epidermal growth factor receptor (EGFR) are well known to regulate repair of damaged alveolar epithelium by stimulating cell migration and proliferation. Recently, TGF-α/EGFR signaling has also been shown to regulate innate immune responses in bronchial epithelial cells. However, little is known about whether HGF/c-Met signaling alters the innate immune responses and whether the innate immune responses in AECs are regulated by HGF/c-Met and TGF-α/EGFR. We hypothesized that HGF/c-Met and TGF-α/EGFR would regulate innate immune responses to influenza A virus infection in human AECs. We found that recombinant human HGF (rhHGF) and rhTGF-α stimulated primary human AECs to secrete IL-8 and granulocyte macrophage colony-stimulating factor (GM-CSF) strongly and IL-6 and monocyte chemotactic protein 1 moderately. Influenza infection stimulated the secretion of IL-8 and GM-CSF by AECs plated on rat-tail collagen through EGFR activation likely by TGF-α released from AECs and through c-Met activated by HGF secreted from lung fibroblasts. HGF secretion by fibroblasts was stimulated by AEC production of prostaglandin E₂ during influenza infection. We conclude that HGF/c-Met and TGF-α/EGFR signaling enhances the innate immune responses by human AECs during influenza infections.

ADAM-family metalloproteinases in lung inflammation: potential therapeutic targets

Acute and chronic lung inflammation is driven and controlled by several endogenous mediators that undergo proteolytic conversion from surface-expressed proteins to soluble variants by a disintegrin and metalloproteinase (ADAM)-family members. TNF and epidermal growth factor receptor ligands are just some of the many substrates by which these proteases regulate inflammatory or regenerative processes in the lung. ADAM10 and ADAM17 are the most prominent members of this protease family. They are constitutively expressed in most lung cells and, as recent research has shown, are the pivotal shedding enzymes mediating acute lung inflammation in a cell-specific manner. ADAM17 promotes endothelial and epithelial permeability, transendothelial leukocyte migration, and inflammatory mediator production by smooth muscle and epithelial cells. ADAM10 is critical for leukocyte migration and alveolar leukocyte recruitment. ADAM10 also promotes allergic asthma by driving B cell responses. Additionally, ADAM10 acts as a receptor for Staphylococcus aureus (S. aureus) α-toxin and is crucial for bacterial virulence. ADAM8, ADAM9, ADAM15, and ADAM33 are upregulated during acute or chronic lung inflammation, and recent functional or genetic analyses have linked them to disease development. Pharmacological inhibitors that allow us to locally or systemically target and differentiate ADAM-family members in the lung suppress acute and asthmatic inflammatory responses and S. aureus virulence. These promising results encourage further research to develop therapeutic strategies based on selected ADAMs. These studies need also to address the role of the ADAMs in repair and regeneration in the lung to identify further therapeutic opportunities and possible side effects.

Transforming growth factor alpha is a critical mediator of radiation lung injury

Radiation fibrosis of the lung is a late toxicity of thoracic irradiation. Epidermal growth factor (EGF) signaling has previously been implicated in radiation lung injury. We hypothesized that TGF-α, an EGF receptor ligand, plays a key role in radiation-induced fibrosis in lung. Mice deficient in transforming growth factor (TGF-α(-/-)) and control C57Bl/6J (C57-WT) mice were exposed to thoracic irradiation in 5 daily fractions of 6 Gy. Cohorts of mice were followed for survival (n ≥ 5 per group) and tissue collection (n = 3 per strain and time point). Collagen accumulation in irradiated lungs was assessed by Masson's trichrome staining and analysis of hydroxyproline content. Cytokine levels in lung tissue were assessed with ELISA. The effects of TGF-α on pneumocyte and fibroblast proliferation and collagen production were analyzed in vitro. Lysyl oxidase (LOX) expression and activity were measured in vitro and in vivo. Irradiated C57-WT mice had a median survival of 24.4 weeks compared to 48.2 weeks for irradiated TGF-α(-/-) mice (P = 0.001). At 20 weeks after irradiation, hydroxyproline content was markedly increased in C57-WT mice exposed to radiation compared to TGF-α(-/-) mice exposed to radiation or unirradiated C57-WT mice (63.0, 30.5 and 37.6 μg/lung, respectively, P = 0.01). C57-WT mice exposed to radiation had dense foci of subpleural fibrosis at 20 weeks after exposure, whereas the lungs of irradiated TGF-α (-/-) mice were largely devoid of fibrotic foci. Lung tissue concentrations of IL-1β, IL-4, TNF-α, TGF-β and EGF at multiple time points after irradiation were similar in C57-WT and TGF-α(-/-) mice. TGF-α in lung tissue of C57-WT mice rose rapidly after irradiation and remained elevated through 20 weeks. TGF-α(-/-) mice had lower basal LOX expression than C57-WT mice. Both LOX expression and LOX activity were increased after irradiation in all mice but to a lesser degree in TGF-α(-/-) mice. Treatment of NIH-3T3 fibroblasts with TGF-α resulted in increases in proliferation, collagen production and LOX activity. These studies identify TGF-α as a critical mediator of radiation-induced lung injury and a novel therapeutic target in this setting. Further, these data implicate TGF-α as a mediator of collagen maturation through a TGF-β independent activation of lysyl oxidase.

Pim1 kinase protects airway epithelial cells from cigarette smoke-induced damage and airway inflammation

Exposure to cigarette smoke (CS) is the main risk factor for developing chronic obstructive pulmonary disease and can induce airway epithelial cell damage, innate immune responses, and airway inflammation. We hypothesized that cell survival factors might decrease the sensitivity of airway epithelial cells to CS-induced damage, thereby protecting the airways against inflammation upon CS exposure. Here, we tested whether Pim survival kinases could protect from CS-induced inflammation. We determined expression of Pim kinases in lung tissue, airway inflammation, and levels of keratinocyte-derived cytokine (KC) and several damage-associated molecular patterns in bronchoalveolar lavage in mice exposed to CS or air. Human bronchial epithelial BEAS-2B cells were treated with CS extract (CSE) in the presence or absence of Pim1 inhibitor and assessed for loss of mitochondrial membrane potential, induction of cell death, and release of heat shock protein 70 (HSP70). We observed increased expression of Pim1, but not of Pim2 and Pim3, in lung tissue after exposure to CS. Pim1-deficient mice displayed a strongly enhanced neutrophilic airway inflammation upon CS exposure compared with wild-type controls. Inhibition of Pim1 activity in BEAS-2B cells increased the loss of mitochondrial membrane potential and reduced cell viability upon CSE treatment, whereas release of HSP70 was enhanced. Interestingly, we observed release of S100A8 but not of double-strand DNA or HSP70 in Pim1-deficient mice compared with wild-type controls upon CS exposure. In conclusion, we show that expression of Pim1 protects against CS-induced cell death in vitro and neutrophilic airway inflammation in vivo. Our data suggest that the underlying mechanism involves CS-induced release of S100A8 and KC.

TWEAK transactivation of the epidermal growth factor receptor mediates renal inflammation

TWEAK, a member of the TNF superfamily, binds to the Fn14 receptor, eliciting biological responses. EGFR signalling is involved in experimental renal injury. Our aim was to investigate the relationship between TWEAK and EGFR in the kidney. Systemic TWEAK administration into C57BL/6 mice increased renal EGFR phosphorylation, mainly in tubular epithelial cells. In vitro, in these cells TWEAK phosphorylated EGFR via Fn14 binding, ADAM17 activation and subsequent release of the EGFR ligands HB-EGF and TGFα. In vivo the EGFR kinase inhibitor Erlotinib inhibited TWEAK-induced renal EGFR activation and downstream signalling, including ERK activation, up-regulation of proinflammatory factors and inflammatory cell infiltration. Moreover, the ADAM17 inhibitor WTACE-2 also prevented those TWEAK-induced renal effects. In vitro TWEAK induction of proinflammatory factors was prevented by EGFR, ERK or ADAM17 inhibition. In contrast, EGFR transactivation did not modify TWEAK-mediated NF-κB activation. Our data suggest that TWEAK transactivates EGFR in the kidney, leading to modulation of downstream effects, including ERK activation and inflammation, and suggest that inhibition of EGFR signalling could be a novel therapeutic tool for renal inflammation.

Risk of interstitial lung disease associated with EGFR-TKIs in advanced non-small-cell lung cancer: a meta-analysis of 24 phase III clinical trials

PURPOSE

To assess the risk of interstitial lung disease (ILD) with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) gefitinib, erlotinib, and afatinib.

METHOD

PubMed databases were searched for relevant articles. Statistical analyses were conducted to calculate the summary incidence, odds ratio (OR), and 95% confidence intervals (CIs) by using either random-effects or fixed-effect models.

RESULTS

The incidence of all-grade and high-grade (≧ grade 3) ILD associated with EGFR-TKIs was 1.6% (95% CI, 1.0-2.4%) and 0.9% (95% CI, 0.6%-1.4%), with a mortality of 13.0% (95% CI, 7.6-21.6%). Patients treated with EGFR-TKIs had a significantly increased risk of developing all-grade (OR, 1.74; 95% CI, 1.25-2.43; P = 0.001) and high-grade (OR, 4.38; 95% CI, 2.18-8.79; P<0.001) ILD. No significant difference in the risk of ILD was found in sub-group analysis according to EGFR-TKIs, percentage of EGFR mutation, study location, EGFR-TKIs-based regimens, and controlled therapy.

CONCLUSIONS

Treatment with EGFR-TKIs is associated with a significantly increased risk of developing ILD.

Assessment of pathological and physiological changes in mouse lung through bronchoalveolar lavage

In animals, environmental exposure such as toxic chemicals and microorganisms or pathophysiological conditions in respiratory system could result in inflammatory response in their lungs. Bronchoalveolar lavage (BAL) is a procedure that can be used to collect samples from animal lungs to efficiently evaluate the immune response by examining both the compositions of cells and fluid from lavage. The profile of inflammatory cells in BAL provides a qualitative description of inflammatory response and the secretion in BAL fluid contains proteins of inflammatory mediators and albumin as a quantitative measurement of inflammation and tissue injury in the lungs. A consistent experimental approach on how to lavage mouse lungs and collect samples is important for a reproducible evaluation of pathological and physiological changes in mouse lung especially for the analysis of inflammation.

Understanding, recognizing, and managing toxicities of targeted anticancer therapies

Answer questions and earn CME/CNE Advances in genomics and molecular biology have identified aberrant proteins in cancer cells that are attractive targets for cancer therapy. Because these proteins are overexpressed or dysregulated in cancer cells compared with normal cells, it was assumed that their inhibitors will be narrowly targeted and relatively nontoxic. However, this hope has not been achieved. Current targeted agents exhibit the same frequency and severity of toxicities as traditional cytotoxic agents, with the main difference being the nature of the toxic effects. Thus, the classical chemotherapy toxicities of alopecia, myelosuppression, mucositis, nausea, and vomiting have been generally replaced by vascular, dermatologic, endocrine, coagulation, immunologic, ocular, and pulmonary toxicities. These toxicities need to be recognized, prevented, and optimally managed.

Repair and Remodeling of airway epithelium after injury in Chronic Obstructive Pulmonary Disease

COPD is thought to develop as a result of chronic exposure to cigarette smoke, occupational or other environmental hazards and it comprises both airways and parenchyma. Acute infections or chronic colonization of airways with bacteria may also contribute to development and/or progression of COPD lung disease. Airway epithelium is the primary target for the inhaled environmental factors and pathogens. The repetitive injury as a result of chronic exposure to environmental factors may result in persistent activation of pathways involved in airway epithelial repair, such as epithelial to mesenchymal transition, altered migration and proliferation of progenitor cells, and abnormal redifferentiation leading to airway remodeling. Development of model systems which mimics chronic airways disease as observed in COPD is required to understand the molecular mechanisms underlying the abnormal airway epithelial repair that are specific to COPD and to also develop novel therapies focused on airway epithelial repair.

Interstitial lung disease associated with gefitinib in Japanese patients with EGFR-mutated non-small-cell lung cancer: combined analysis of two Phase III trials (NEJ 002 and WJTOG 3405)

OBJECTIVE

Interstitial lung disease associated with gefitinib is a critical adverse reaction. When geftinib was administered to EGFR-unknown patients, the interstitial lung disease incidence rate was approximately 3-4% in Japan, and usually occurs during the first 4 weeks of treatment. However, it has not been fully investigated in EGFR-mutated patients.

METHODS

We collected clinical records of participants of two Phase III trials (WJTOG 3405 and NEJ 002), which compared gefitinib with platinum doublet chemotherapy. All patients were EGFR mutated, chemo-naïve and had good performance status.

RESULTS

A total of 402 patients were enrolled in this study. In the gefitinib arm, 10 (5.0%) of 201 patients developed interstitial lung disease, of whom five (2.5%) were Grade 3 or greater, with two deaths (1.0%). In contrast, only one patient developed interstitial lung disease (Grade 1) in the chemotherapy arm. With regard to gefitinib, smoking history was significantly associated with developing interstitial lung disease (odds ratio 0.18; 95% confidence interval: 0.05-0.74; P = 0.01). The cumulative incidence rate of interstitial lung disease was similar in the 0-4, 5-8 and 9-12 week time periods. However, between smokers and never-smokers, cumulative incidence rates in the first 4 weeks were significantly different (4.7% versus 0%, P = 0.03). Three of 10 patients developed interstitial lung disease after 8 weeks of gefitinib administration (days 135, 171 and 190, respectively).

CONCLUSIONS

Among EGFR-mutated patients, the incidence of interstitial lung disease associated with gefitinib was not different from that in previous reports. Smoking history was associated with developing interstitial lung disease, and smokers had a higher incidence rate of interstitial lung disease in the first 4 weeks.

Dual oxidase-1 is required for airway epithelial cell migration and bronchiolar reepithelialization after injury

The respiratory epithelium plays a critical role in innate defenses against airborne pathogens and pollutants, and alterations in epithelial homeostasis and repair mechanisms are thought to contribute to chronic lung diseases associated with airway remodeling. Previous studies implicated the nicotinamide adenine dinucleotide phosphate-reduced oxidase dual oxidase-1 (DUOX1) in redox signaling pathways involved in in vitro epithelial wound responses to infection and injury. However, the importance of epithelial DUOX1 in in vivo epithelial repair pathways has not been established. Using small interfering (si)RNA silencing of DUOX1 expression, we show the critical importance of DUOX1 in wound responses in murine tracheal epithelial (MTE) cells in vitro, as well as its contribution to epithelial regeneration in vivo in a murine model of epithelial injury induced by naphthalene, a selective toxicant of nonciliated respiratory epithelial cells (club cells [Clara]). Whereas naphthalene-induced club-cell injury is normally followed by epithelial regeneration after 7 and 14 days, such airway reepithelialization was significantly delayed after the silencing of airway DUOX1 by oropharyngeal administration of DUOX1-targeted siRNA. Wound closure in MTE cells was related to DUOX1-dependent activation of the epidermal growth factor receptor (EGFR) and the transcription factor signal transducer and activator of transcription-3 (STAT3), known mediators of epithelial cell migration and wound responses. Moreover, in vivo DUOX1 silencing significantly suppressed naphthalene-induced activation of STAT3 and EGFR during early stages of epithelial repair. In conclusion, these experiments demonstrate for the first time an important function for epithelial DUOX1 in lung epithelial regeneration in vivo, by promoting EGFR-STAT3 signaling and cell migration as critical events in initial repair.