Novel therapeutic strategies targeting bypass pathways and mitochondrial dysfunction to combat resistance to RET inhibitors in NSCLC.

RET fusion is an oncogenic driver in 1-2 % of patients with non-small cell lung cancer (NSCLC). Although RET-positive tumors have been treated with multikinase inhibitors such as vandetanib or RET-selective inhibitors, ultimately resistance to them develops. Here we established vandetanib resistance (VR) clones from LC-2/ad cells harboring CCDC6-RET fusion and explored the molecular mechanism of the resistance. Each VR clone had a distinct phenotype, implying they had acquired resistance via different mechanisms. Consistently, whole exome-seq and RNA-seq revealed that the VR clones had unique mutational signatures and expression profiles, and shared only a few common remarkable events. AXL and IGF-1R were activated as bypass pathway in different VR clones, and sensitive to a combination of RET and AXL inhibitors or IGF-1R inhibitors, respectively. SMARCA4 loss was also found in a particular VR clone and 55 % of post-TKI lung tumor tissues, being correlated with higher sensitivity to SMARCA4/SMARCA2 dual inhibition and shorter PFS after subsequent treatments. Finally, we detected an increased number of damaged mitochondria in one VR clone, which conferred sensitivity to mitochondrial electron transfer chain inhibitors. Increased mitochondria were also observed in post-TKI biopsy specimens in 13/20 cases of NSCLC, suggesting a potential strategy targeting mitochondria to treat resistant tumors. Our data propose new promising therapeutic options to combat resistance to RET inhibitors in NSCLC.

Significance of Persistent Systemic Support in the Clinical Course of Delayed Post-hypoxic Leukoencephalopathy Following Severe Coronavirus Disease 2019.

A 45-year-old woman was hospitalized with severe coronavirus disease 2019 pneumonia. Following cytokine storm-induced multiorgan failure and lethal arrhythmia, the patient developed a sustained coma with flaccid quadriplegia. A cerebrospinal fluid examination excluded infectious and immunogenic encephalopathies, and diffusion-weighted magnetic resonance imaging demonstrated high-intensity areas in the white matter with a cortex-sparing distribution, suggesting delayed post-hypoxic leukoencephalopathy. As a result of intensive cardiopulmonary support for a month, the neurological function gradually recovered. Based on the reversible clinical course noted in this patient, accurate diagnosis and persistent medical approaches are important for the management of coronavirus disease 2019-related delayed post-hypoxic leukoencephalopathy.

Patient-derived spheroids and patient-derived organoids simulate evolutions of lung cancer.

Cancer cells harbor many genetic mutations and gene expression profiles different from normal cells. Patient-derived cancer cells (PDCC) are preferred materials in cancer study. We established patient-derived spheroids (PDSs) and patient-derived organoids (PDOs) from PDCCs isolated from the malignant pleural effusion in 8 patients. The morphologies suggested that PDSs may be a model of local cancer extensions, while PDOs may be a model of distant cancer metastases. The gene expression profiles differed between PDSs and PDOs: Gene sets related to inflammatory responses and EMT were antithetically regulated in PDSs or in PDOs. PDSs demonstrated an attenuation of the pathways that contribute to the enhancement of transforming growth factor beta (TGF-ß) induced epithelial mesenchymal transition (EMT), while PDOs demonstrated an attenuation of it. Taken together, PDSs and PDOs have differences in both the interaction to the immune systems and to the stroma. PDSs and PDOs will provide a model system that enable intimate investigation of the behavior of cancer cells in the body.

Virulent Pseudomonas aeruginosa pneumonia in an immunocompetent adult associated with a home whirlpool bath: A case report.

We present a case of life-threatening pneumonia caused by Pseudomonas aeruginosa (P. aeruginosa) in a healthy 67-year-old man. Rapid disseminated infection resulted in the right hemorrhagic pneumonia and bacteremia. Antimicrobial therapy had limited effects, radical pneumonectomy eventually resolved the prolonged infection. Concurrently, we explored the environmental factors responsible for fulminant P. aeruginosa infection. Multi-locus sequence typing demonstrated that P. aeruginosa isolated from the patient was identical to that collected from home whirlpool bath by the common virulent factor gene. Massive inhalation of contaminated aerosol and pathogen virulence may have synergistically contributed to the severity in this case.

Highly sensitive detection of driver mutations from cytological samples and cfDNA in lung cancer.

BACKGROUND: Bronchoscopy is a minimally invasive procedure for establishing the diagnosis of lung cancer. It sometimes fails to obtain tissue samples but readily collects cytological samples. METHODS: We developed PNA-LNA dual-PCR (PLDP), which amplified mutant sequences by a high-fidelity DNA polymerase in the presence of a peptide nucleic acid (PNA) oligomer having a wild-type sequence. Mutations are detected either by locked nucleic acid (LNA) probes for quick detection of a limited number of mutations, which are EGFR, KRAS, and BRAF mutations in the current study, or by direct sequencing for a comprehensive screening. In a total of 233 lung cancer samples, the results for cytological samples by PLDP were compared with those for tissue samples by cobas® EGFR mutation test (cobas) or by the PNA-LNA PCR clamp method (P-LPC). Moreover, the performance of PLDP using cell-free DNA (cfDNA) was investigated. RESULTS: Peptide nucleic acid-LNA dual-PCR was able to detect each synthesized mutant sequence with high sensitivity. PLDP detected EGFR mutations in 80 out of 149 clinical samples, while the cobas or the P-LPC detected in 66 matched. The correctness of PLDP was confirmed both by clinical response and by the results of sequencing using a next-generation sequencer. PLDP detected mutations from cfDNA in approximately 70% of patients who harbors mutations in the tumor. CONCLUSIONS: Peptide nucleic acid-LNA dual-PCR exhibited an excellent performance, even using cytological samples. PLDP is applicable for the investigation of cfDNA. The combination of bronchoscopy and PLDP is attractive and will expand the utility of bronchoscopy in clinical practice.

Cytological detection of metastatic chordoma cells in pleural effusions: A case report.

Cytological detection of chordoma cells in the serosal cavity is challenging because of its rare presentation. Herein, we report a case of chordoma showing malignant pleural effusion accompanied by pleuropulmonary metastases in a 68-year-old woman. Cytological analysis was performed using pleural fluid obtained following thoracentesis. Conventional cytological staining demonstrated few clusters of large, atypical cells characterized by epithelial cell-like connectivity and rich cytoplasm with foamy and/or multivacuolar changes. The nuclei of these atypical cells were large and either round or oval with no conspicuous irregularities in the nuclear membrane. Periodic acid-Schiff staining of these atypical cells revealed fine granules in the cytoplasm. Giemsa staining showed foamy and/or multivacuolar cytoplasm in these cells, with metachromatic mucoid stroma in the surroundings. Immunocytochemistry analysis using cellblock showed these cells to be positive for broad cytokeratins, epithelial membrane antigen, S100 protein, vimentin, and Brachyury. To the best of our knowledge, this is the first case report in which chordoma cells were cytologically detected in pleural effusions. Our findings also suggest that conventional cytology combined with cellblock immunocytochemistry can increase the accuracy of chordoma cell detection in the serosal cavity.

A comparative study of the Parker Flex-Tip tube versus standard portex tube for oral fiberoptic intubation in bronchoscopy performed by pulmonologists with limited experience.

BACKGROUND: Fiberoptic tracheal intubation (FTI) in bronchoscopy is widely performed with a conventional Portex tracheal tube (PTT). Occasionally, it is difficult for pulmonologists with limited experience to insert a tube beyond the vocal cords and advance it into the trachea. A new endotracheal tube, the Parker Flex-Tip tube (PFT), was recently designed. We compared the usefulness and safety of PFT versus PTT for FTI in bronchoscopy performed by pulmonologists with limited experience. METHODS: Forty consecutive patients were enrolled and randomly assigned to either the PFT group (n = 20) or PTT group (n = 20). The time required for the tip of the endotracheal tube to pass from the mouth to the carina, the number of vomiting reflexes, the number of attempts to pass the tube through the vocal cords during intubation, complications, and technical difficulty of intubation were evaluated. RESULTS: Both the PFT and PTT groups exhibited high intubation success rates (100% vs. 90%, respectively). The PFT group was intubated faster than the PTT group (11.5 [5-45] s vs. 22.5 [8-270] s, respectively, p < 0.01). The PFT group showed fewer vomiting reflexes and tube impingements than the PTT group (p < 0.05). Operators felt it was easier to intubate with PFT versus PTT (p < 0.01). Complications were not significantly different between the two groups. CONCLUSION: For pulmonologists with limited experience who perform FTI in bronchoscopy, intubation using PFT versus PTT is faster and easier, without an increase in complications.

A case of lymphocytic interstitial pneumonia presenting with a ground glass nodule as an initial finding.

A 65-year-old woman had a ground glass nodule, which was suspicious for lung cancer, in her right lung S6 by chest computed tomography. For diagnosis, video-assisted thoracoscopic surgery was performed, and the specimen showed a pathological pattern of lymphocytic interstitial pneumonia (LIP). Four years after surgery, new localized ground glass shadows gradually increased on the base of the lung. However, because she had no respiratory symptoms and had normal respiratory function, she was observed with no medication. Subsequently, no other underlying diseases associated with LIP developed. The ground glass nodule was the initial lesion of LIP.

CD103hi Treg cells constrain lung fibrosis induced by CD103lo tissue-resident pathogenic CD4 T cells.

Tissue-resident memory T cells (TRM cells) are crucial mediators of adaptive immunity in nonlymphoid tissues. However, the functional heterogeneity and pathogenic roles of CD4+ TRM cells that reside within chronic inflammatory lesions remain unknown. We found that CD69hiCD103lo CD4+ TRM cells produced effector cytokines and promoted the inflammation and fibrotic responses induced by chronic exposure to Aspergillus fumigatus. Simultaneously, immunosuppressive CD69hiCD103hiFoxp3+ CD4+ regulatory T cells were induced and constrained the ability of pathogenic CD103lo TRM cells to cause fibrosis. Thus, lung tissue-resident CD4+ T cells play crucial roles in the pathology of chronic lung inflammation, and CD103 expression defines pathogenic effector and immunosuppressive tissue-resident cell subpopulations in the inflamed lung.

Inflammasome-Independent and Atypical Processing of IL-1ß Contributes to Acid Aspiration-Induced Acute Lung Injury.

Inflammation plays a pivotal role in the pathophysiology of gastric aspiration-induced acute lung injury (ALI). However, its mechanism remains unclear. In this study, we investigated the role of NLRP3 inflammasome-driven IL-1ß production in a mouse model of acid aspiration-induced inflammation and ALI. Acid aspiration-induced inflammatory responses and ALI in wild-type mice were significantly attenuated in IL-1ß-/- mice, but not NLRP3-/- mice. In vitro experiments revealed that severe acidic stress (pH 1.75) induced the processing of pro-IL-1ß into its 18-kDa mature form (p18-IL-1ß), which was different from the caspase-1-processed 17-kDa form (p17-IL-1ß), in human THP-1 macrophages and primary murine macrophages. Deficiency of NLRP3 and caspase-1 had no effect on acidic stress-produced IL-1ß. The production of IL-1ß by severe acidic stress was prevented by inhibitors of serine proteases [4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride], but not of cysteine proteases (E-64), cathepsin G, or inflammasome. The cathepsin D inhibitor pepstatin A inhibited IL-1ß production induced by mild acidic stress (pH 6.2) or lactic acid, but not severe acidic stress. Using mass spectrometry and processing-site mutants of pro-IL-1ß, we identified D109 as a novel cleavage site of pro-IL-1ß in response to severe acidic stress and calculated the theoretical molecular mass of the mature form to be 18.2 kDa. The bioactivity of acidic stress-produced IL-1ß was confirmed by its ability to promote p38 phosphorylation and chemokine upregulation in alveolar epithelial cells. These findings demonstrate a novel mechanism of acid-induced IL-1ß production and inflammation independent of NLRP3 inflammasome and provide new insights into the therapeutic strategies for aspiration pneumonitis and ALI.

Transcatheter Proximal Coil Blocking with n-Butyl-2-Cyanoacrylate Injection via the Pulmonary Artery Alone for Rasmussen's Aneurysm.

Rasmussen's aneurysm is a peripheral pulmonary artery pseudoaneurysm (PAP) within a tuberculosis cavity. Because it can be perfused from the bronchial and pulmonary arterial circulations, combined embolization via the bronchial and pulmonary arteries is sometimes required. Herein, we present case of a 51-year-old man with Rasmussen's aneurysm that was successfully treated by proximal coil blocking with n-butyl-2-cyanoacrylate (NBCA) injection via the pulmonary artery alone. With proximal coil blocking, a sufficient amount of NBCA could be injected without unintended reflux of the NBCA cast to the proximal pulmonary artery. To our knowledge, there has been no report that attempted NBCA injection under proximal coil blocking for Rasmussen's aneurysm. Our treatment approach may be safe and effective for infectious lung disease-related PAP, which has to be treated from the pulmonary artery side.

Pazopanib Confers a Progression-free Survival in a Patient with Ewing's Sarcoma/Primitive Neuroectodermal Tumor of the Lung.

Ewing's sarcoma (ES)/primitive neuroectodermal tumors (PNETs) are highly malignant neoplasms that usually affect the bones and soft tissues in children and young adults. ES/PNET of the lung is very rare and is associated with a poor prognosis. We herein report a case of ES/PNET of the left lung in a 45-year-old man. He was treated with neoadjuvant chemotherapy and pneumonectomy, but unfortunately his disease recurred 1.5 months after surgery. He was started on pazopanib, which resulted in a five-month progression-free survival. To our knowledge, this is the first demonstration of pazopanib efficacy in ES/PNET of the lung.

Use of low-cost three-dimensional printer to simulate grasping of bronchial foreign body.

An 89-year-old man was hospitalized with severe pneumonia. Chest computed tomography showed a foreign body in the left main bronchus. We moulded a three-dimensional (3D) model of the foreign body with a low-cost 3D printer and found it had the shape of a tooth. We simulated grasping the model with several forceps and succeeded in grasping it with a retrieval net and shark-tooth forceps. Bronchoscopy was performed after his respiratory condition improved. We found a dental foreign body that had accidentally moved and become stuck in the right upper bronchus. We scraped it out with a retrieval net and grasped the recess site of the foreign body with a shark-tooth forceps as performed in the simulation. Removal was successful, and the total bronchoscopy time was 9 min. The bronchial foreign body was safely grasped and removed in a short time after simulation with several forceps using a low-cost 3D printer.

The pathogenicity of IL-33 on steroid-resistant eosinophilic inflammation via the activation of memory-type ST2+ CD4+ T cells.

The lungs are the primary organs of the respiratory system in many animals and have unique epithelial barrier systems to protect the host from continuous invasion of various harmful particles, such as viruses and bacteria. IL-33, a member of the IL-1 family of cytokines, is released from epithelial cells in the mucosal organs and drives the type 2 immune response by activating a number of immune cells in cases of helminth infection. However, IL-33 derived from epithelial cells also causes various allergic diseases via the activation of ST2-positive immune cells, including memory-type (CD62Llow CD44hi ) ST2+ CD4+ T cells in the lung. Recent studies have revealed that the type 2 inflammation induced by IL-33 is steroid resistant. Steroid resistance causes severe chronic inflammatory diseases, such as intractable asthma. In this review, we will discuss the impact of ST2+ CD4+ T cells on shaping the pathology of IL-33-induced eosinophilic inflammation. We will also highlight the mechanism underlying steroid resistance in eosinophilic pneumonia. A better understanding of the cellular and molecular mechanisms underlying steroid resistance is crucial for the development of new therapeutic strategies for intractable allergic diseases.

Clinical significance of changes in Torque teno virus DNA titer after chemotherapy in patients with primary lung cancer.

BACKGROUND: Several studies have reported that viral infections are related to lung cancer. We previously reported the involvement of Torque teno virus (TTV) in patients with lung cancer and idiopathic pulmonary fibrosis. However, the role of TTV in lung cancer growth, and its influence on changes in TTV DNA titers due to idiopathic pulmonary fibrosis (IPF) in lung cancer patients are poorly understood. METHODS: Serum TTV DNA titers were measured in serum samples obtained from patients with lung cancer. Forty-eight patients with primary lung cancer, including 8 patients with IPF, were enrolled. Serum TTV DNA titers were quantitated before and after chemotherapy. In addition, patients were classified into two groups according to the presence or absence of IPF, and clinical characteristics were compared between these two groups. RESULTS: Among the 33 patients with partial response to treatment or stable disease in the lung cancer, the mean TTV DNA titer in 28 patients without IPF had significantly decreased after chemotherapy. In contrast, the mean TTV DNA titer in the 5 patients with IPF tended to increase after chemotherapy. In the 15 patients with progressive lung cancer, TTV DNA titers were significantly elevated in those with and without IPF. CONCLUSION: In lung cancer patients without IPF, changes in TTV titers may be correlated with tumor growth. However, in lung cancer patients with IPF, TTV titers were not consistently associated with chemotherapy responses. Therefore, IPF may have an influence on changes in TTV DNA titers.

Nephrotic Syndrome and a Retroperitoneal Mass: A Case Report of a Patient with Recurrent Invasive Thymoma.

A 68-year-old man was admitted to our hospital to undergo an examination for nephrotic syndrome while concurrently complicated with recurrent thymoma in the parietal pleura and retroperitoneum. He had been diagnosed with invasive thymoma and had undergone thymo-thymectomy seven years previously. Based on the renal biopsy findings, his nephrotic syndrome was ascribed to minimal change disease. He was treated with corticosteroid monotherapy, which resulted in complete remission six months later, despite the fact that the recurrent thymoma remained. The role of thymoma in the pathogenesis of paraneoplastic glomerulopathy and the therapeutic concerns that emerged in this case are also discussed.

Memory-type ST2+CD4+ T cells participate in the steroid-resistant pathology of eosinophilic pneumonia.

The lung develops an unique epithelial barrier system to protect host from continuous invasion of various harmful particles. Interleukin (IL-)33 released from epithelial cells in the lung drives the type 2 immune response by activating ST2- expressed immune cells in various allergic diseases. However, the involvement of memory-type ST2+CD4+ T cells in such lung inflammation remains unclear. Here we demonstrated that intratracheal administration of IL-33 resulted in the substantial increase of numbers of tissue-resident memory-type ST2+CD4+ T cells in the lung. Following enhanced production of IL-5 and IL-13, eosinophilic lung inflammation sequentially developed. IL-33-mediated eosinophilic lung inflammation was not fully developed in T cell-deficient Foxn1 nu mice and NSG mice. Dexamethasone treatment showed limited effects on both the cell number and function of memory-type ST2+CD4+ T cells. Thus our study provides novel insight into the pathogenesis of eosinophilic lung disease, showing that memory-type ST2+CD4+ T cells are involved in IL-33-induced eosinophilic inflammation and elicited steroid-resistance.

Nutritional control of IL-23/Th17-mediated autoimmune disease through HO-1/STAT3 activation.

The nutritional curcumin (CUR) is beneficial in cell-mediated autoimmune diseases. The molecular mechanisms underlying this food-mediated silencing of inflammatory immune responses are poorly understood. By investigating antigen-specific immune responses we found that dietary CUR impairs the differentiation of Th1/Th17 cells in vivo during encephalomyelitis and instead promoted Th2 cells. In contrast, feeding CUR had no inhibitory effect on ovalbumin-induced airway inflammation. Mechanistically, we found that CUR induces an anti-inflammatory phenotype in dendritic cells (DC) with enhanced STAT3 phosphorylation and suppressed expression of Il12b and Il23a. On the molecular level CUR readily induced NRF2-sensitive heme oxygenase 1 (HO-1) mRNA and protein in LPS-activated DC. HO-1 enhanced STAT3 phosphorylation, which enriched to Il12b and Il23a loci and negatively regulated their transcription. These findings demonstrate the underlying mechanism through which a nutritional can interfere with the immune response. CUR silences IL-23/Th17-mediated pathology by enhancing HO-1/STAT3 interaction in DC.

Influence of Smoking in Interstitial Pneumonia Presenting with a Non-Specific Interstitial Pneumonia Pattern.

Objective The influence of smoking on the pathogenesis and clinical course of interstitial pneumonia has recently attracted attention. To clarify the influence of smoking on the clinical patient characteristics and therapeutic effects in patients with interstitial pneumonia presenting with a non-specific interstitial pneumonia (NSIP) pattern, we compared the clinical patient characteristics and therapeutic effects in smokers and nonsmokers in this study. Methods We divided 31 NSIP (16 idiopathic nonspecific interstitial pneumonia and 15 collagen vascular disease-associated nonspecific interstitial pneumonia) patients into smoker and non-smoker groups for each case. The patient characteristics, pulmonary function tests, Krebs von den Lungen 6 (KL-6), surfactant protein D (SP-D), bronchoalveolar lavage fluid findings, and clinical courses for two years were compared between the smoker and non-smoker groups. Results The smoking subgroup (n=15) of NSIP patients had a significantly lower % diffusing capacity for carbon monoxide/ alveolar ventilation (DLCO/VA) and tended to have higher SP-D values than the nonsmoking subgroup (n=16). Although no difference was observed regarding the prognosis, 5 of 6 cases with NSIP, which had worsening of lung disease were heavy smokers with a pack-year history of 40 or greater. Conclusion Smoking is thus suggested to negatively influence the diffusing capacity caused by damage to alveolar epithelial cells. In addition, smoking may also be potentially related to resistance to therapy in NSIP cases.