CALML5 is a novel diagnostic marker for differentiating thymic squamous cell carcinoma from type B3 thymoma.

BACKGROUND: Thymic squamous cell carcinoma and type B3 thymoma are primary neoplasms of the anterior mediastinum that are sometimes difficult to differentiate from one another histologically. However, only a few immunohistochemical markers are available for the differential diagnosis. The purpose of this study was to discover a novel marker for differentiating between thymic squamous cell carcinoma and type B3 thymoma. METHODS: We used histological samples of thymic carcinomas (n = 26) and type B3 thymomas (n = 38) which were resected between 1986 and 2017. To search for candidates of differential markers, gene expression levels were evaluated in samples using promoter analysis by cap analysis of gene expression (CAGE) sequencing. RESULTS: Promoter level expression of CALML5 genes was significantly higher in thymic carcinomas than in type B3 thymomas. We further validated the results of the CAGE analysis in all 26 thymic carcinomas and 38 type B3 thymomas by immunohistochemistry (IHC). CALML5 was strongly expressed in the cytoplasm in 19 of 26 cases with thymic carcinoma, whereas positivity at the protein level was shown in two of 38 type B3 thymomas. Thus, the sensitivity (73.1%) and specificity (94.7%) of CALML5 as markers for immunohistochemical diagnosis of thymic carcinoma were extremely high. CONCLUSION: We identified CALML5 as a potential marker for differentiating thymic squamous cell carcinoma from type B3 thymoma. It is assumed that future clinical use of CALML5 may improve the diagnostic accuracy of differentiating between these two diseases.

Early Detection of Therapeutic Benefit from PD-1/PD-L1 Blockade in Advanced Lung Cancer by Monitoring Cachexia-Related Circulating Cytokines.

Cancer cachexia is associated with poor immunotherapeutic outcomes. This prospective observational study longitudinally evaluated the role of cachexia-related circulating cytokines in predicting the risk and benefit of PD-1/PD-L1 blockade in advanced lung cancer. Forty-one circulating cytokines at baseline and after one cycle of PD-1/PD-L1 blockade treatment were measured in patients with advanced lung cancer between 2019 and 2020. The cachexia-related cytokines were identified by comparing the levels of circulating cytokines between cachectic and non-cachectic patients. Among 55 patients, 49.1% were diagnosed with cachexia at the beginning of PD-1/PD-L1 blockade therapy. Baseline levels of the circulating cytokines IL-6, IL-8, IL-10, IL-15, and IP-10 were significantly higher in cachectic patients. In contrast, the level of eotaxin-1 was lower in cachectic patients than in those without cachexia. Higher IL-6 at baseline and during treatment was associated with a greater risk of immune-related adverse events, while higher IL-10 at baseline was linked to worse overall survival. More importantly, increased eotaxin-1 after one cycle of PD-1/PD-L1 blockade treatment was associated with higher objective response and better overall survival. A blood-based, cachexia-related cytokine assay may yield potential biomarkers for the early prediction of clinical response to PD-1/PD-L1 blockade and provide clues for improving the outcomes of cachectic patients.

Comparison of ASCL1, NEUROD1, and POU2F3 expression in surgically resected specimens, paired tissue microarrays, and lymph node metastases in small cell lung carcinoma.

Subtypes of small cell lung carcinoma (SCLC) are defined by the expression of ASCL1, NEUROD1, and POU2F3 markers. The aim of our study was to explore the extent to which the intratumoral heterogeneity of ASCL1, NEUROD1, and POU2F3 may lead to discrepancies in expression of these markers in surgical samples and their matched tissue microarray (TMA) and lymph node (LN) metastatic sites. METHODS AND RESULTS: The cohort included 77 patients with SCLC. Immunohistochemical examinations were performed on whole slides of the primary tumour, paired TMAs, and metastatic LN sites. Samples with H-scores >50 were considered positive. Based on the ASCL1, NEUROD1, and POU2F3 staining pattern, we grouped the tumours as follows: ASCL1-dominant (SCLC-A), NEUROD1-dominant (SCLC-N), ASCL1/NEUROD1 double-negative with POU2F3 expression (SCLC-P), and negative for all three markers (SCLC-I). In whole slides, 40 SCLC-A (52%), 20 SCLC-N (26%), 15 SCLC-P (20%), and two SCLC-I (3%) tumours were identified. Comparisons of TMAs or LN metastatic sites and corresponding surgical specimens showed that positivity for ASCL1, NEUROD1, and POU2F3 in TMAs (all P < 0.0001) or LN metastatic sites (ASCL1, P = 0.0047; NEUROD1, P = 0.0069; POU2F3, P < 0.0001) correlated significantly with that of corresponding surgical specimens. CONCLUSION: The positivity for these markers in TMAs and LN metastatic sites was significantly correlated with that of corresponding surgical specimens, indicating that biopsy specimens could be used to identify molecular subtypes of SCLC in patients.

Successful restart of chemotherapy in a patient with primary mediastinal nonseminomatous germ cell tumor after COVID-19 infection.

Cancer patients are considered highly susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, it is not well known when chemotherapy can be safely restarted in cancer patients after coronavirus disease 2019 (COVID-19). Here, we describe the case of an 18-year-old man diagnosed with primary mediastinal nonseminomatous germ cell tumor (PMNSGCT) in which chemotherapy could be safely restarted after COVID-19. On day 11 of the third cycle of bleomycin, etoposide, plus cisplatin (BEP), he was diagnosed with mild COVID-19. On day 16 after the onset of COVID-19 (day 26 of third cycle of BEP), chemotherapy for his PMNSGCT was restarted. He received surgery after the fourth cycle of BEP without recurrence of COVID-19. Chemotherapy could be restarted and followed by surgery in this post-COVID-19 patient who had experienced mild illness after the discharge criteria were met and all symptoms had disappeared. We report this case with a review of the literature on restarting chemotherapy after SARS-CoV2 infection.

Survival past five years with advanced, EGFR-mutated or ALK-rearranged non-small cell lung cancer-is there a "tail plateau" in the survival curve of these patients?

BACKGROUND: The prognosis of patients with NSCLC harboring oncogenic driver gene alterations, such as EGFR gene mutations or ALK fusion, has improved dramatically with the advent of corresponding molecularly targeted drugs. As patients were followed up for about five years in most clinical trials, the long-term outcomes beyond 5 years are unclear. The objectives of this study are to explore the clinical course beyond five years of chemotherapy initiation and to investigate factors that lead to long-term survival. METHODS: One hundred and seventy-seven patients with advanced, EGFR-mutated or ALK-rearranged NSCLC who received their first chemotherapy between December 2008 and September 2015 were included. Kaplan Meier curves were drawn for the total cohort and according to subgroups of patients' characteristics. RESULTS: Median OS in the total cohort was 40.6 months, the one-year survival rate was 89%, the three-year survival rate was 54%, and the five-year survival rate was 28%. Median OS was 36.9 months in EGFR-mutated patients and 55.4 months in ALK-rearranged patients. The OS curve seemed to plateau after 72 months, and most of the patients who were still alive after more than five years are on treatment. Female sex, age under 75 years, an ECOG PS of 0 to 1, ALK rearrangement, postoperative recurrence, and presence of brain metastasis were significantly associated with longer OS. CONCLUSIONS: A tail plateau was found in the survival curves of patients with advanced, EGFR-mutated and ALK-rearranged NSCLC, but most were on treatment, especially with EGFR-mutated NSCLC.

A Novel Therapeutic Strategy Targeting the Mesenchymal Phenotype of Malignant Pleural Mesothelioma by Suppressing LSD1.

Malignant pleural mesothelioma (MPM) is a highly aggressive tumor that has a low overall survival; however, no significant treatment advances have been made in the past 15 years. Large-scale molecular studies have identified a poor prognostic subset of MPM linked to the epithelial-mesenchymal transition (EMT) that may contribute toward resistance to chemotherapy, suggesting that EMT could be targeted to treat patients with MPM. Previously, we reported that histone modifiers regulating EMT could be therapeutic targets; therefore, in this study, we investigated whether targeting lysine-specific demethylase 1 (LSD1/KDM1), a histone-modifying enzyme responsible for demethylating histone H3 lysine 4 and lysine 9, could represent a novel therapeutic strategy for MPM. We suppressed LSD1 and investigated the EMT phenotype using EMT marker expression and wound-healing assay; and chemosensitivity using apoptosis assay. We found that suppressing LSD1 induces an epithelial phenotype in sarcomatoid MPM cells, while attenuating the mesenchymal phenotype sensitized MPM cells to cisplatin-induced apoptosis. Subsequent genome-wide identification, comprehensive microarray analysis, and Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) to assess genome-wide changes in chromatin accessibility suggested that LSD1 directly regulates milk fat globulin protein E8 (MFGE8), an integrin ligand that is involved in the FAK pathway. Furthermore, we found that LSD1 regulates the mesenchymal phenotype and apoptosis by activating the FAK-AKT-GSK3ß pathway via a positive feedback loop involving MFGE8 and Snail expression, thereby leading to cisplatin resistance. IMPLICATIONS: This study suggests that LSD1 regulates the mesenchymal phenotype and apoptosis, and that LSD1 inhibitors could be combined with the cisplatin as a novel therapy for patients with MPM.

SCLC-J1, a novel small cell lung cancer cell line.

Small cell lung cancer (SCLC) is a type of high-grade neuroendocrine carcinoma. It initially responds to chemotherapy but rapidly becomes chemoresistant and it is highly proliferative. The prognosis in SCLC is poor. We have established a novel SCLC cell line, SCLC-J1, from a malignant pleural effusion in a patient with advanced SCLC. SCLC-J1 cells express ganglioside GD2, CD276, and Delta-like protein 3. RB1 is lost. These features of the new SCLC cell line may be useful in understanding the cellular and molecular biology of SCLC and in designing better treatment.

Zinc-finger E-box-binding homeobox 1 (ZEB1) plays a crucial role in the maintenance of lung cancer stem cells resistant to gefitinib.

BACKGROUND: Zinc-finger E-box-binding homeobox 1 (ZEB1) is an important regulator of epithelial-mesenchymal transition (EMT) and is involved in the maintenance of cancer stem cells (CSCs) via miR-200c and BMI1 pathway. Recent studies revealed that ZEB1 contributes to the EMT-mediated acquired resistance to gefitinib in EGFR-mutant non-small cell lung cancer (NSCLC). However, the precise role of ZEB1 in the maintenance of lung CSCs that lead to acquired resistance to gefitinib remains unclear. METHODS: PC9 and HCC827 NSCLC cell lines were treated with high concentrations of gefitinib, and surviving cells were referred to as "gefitinib-resistant persisters" (GRPs). ZEB1 knockdown or overexpression was performed to determine the biological significance of ZEB1 in the CSC features of GRPs, and animal models were studied for in vivo validation. Expression of ZEB1, BMI1, and ALDH1A1 was analyzed by immunohistochemistry in tumor specimens from NSCLC patients with acquired resistance to gefitinib. RESULTS: GRPs had characteristic features of mesenchymal and CSC phenotypes with high expression of ZEB1 and BMI1, and decreased miR-200c, in vitro and in vivo. ZEB1 silencing attenuated the suppression of miR-200c, resulting in the reduction in BMI1 and reversed the mesenchymal and CSC features of GRPs. Furthermore, ZEB1 overexpression induced EMT and increased the levels of CD133- and BMI1-positive GRPs in vitro and gefitinib resistance in vivo. Finally, ZEB1, BMI1, and ALDH1A1 were highly expressed in tumor specimens from EGFR-mutant NSCLC patients with gefitinib resistance. CONCLUSIONS: ZEB1 plays an important role in gefitinib-resistant lung CSCs with EMT features via regulation of miR-200c and BMI1.

Tranilast Inhibits Pulmonary Fibrosis by Suppressing TGFß/SMAD2 Pathway.

PURPOSE: Idiopathic pulmonary fibrosis (IPF) is characterized by the accumulation of extracellular matrix (ECM) protein in the lungs. Transforming growth factor (TGF) ß-induced ECM protein synthesis contributes to the development of IPF. Tranilast, an anti-allergy drug, suppresses TGFß expression and inhibits interstitial renal fibrosis in animal models. However, the beneficial effects of tranilast or its mechanism as a therapy for pulmonary fibrosis have not been clarified. METHODS: We investigated the in vitro effect of tranilast on ECM production and TGFß/SMAD2 pathway in TGFß2-stimulated A549 human alveolar epithelial cells, using quantitative polymerase chain reaction, Western blotting, and immunofluorescence. In vitro observations were validated in the lungs of a murine pulmonary fibrosis model, which we developed by intravenous injection of bleomycin. RESULTS: Treatment with tranilast suppressed the expression of ECM proteins, such as fibronectin and type IV collagen, and attenuated SMAD2 phosphorylation in TGFß2-stimulated A549 cells. In addition, based on a wound healing assay in these cells, tranilast significantly inhibited cell motility, with foci formation that comprised of ECM proteins. Histological analyses revealed that the administration of tranilast significantly attenuated lung fibrosis in mice. Furthermore, tranilast treatment significantly reduced levels of TGFß, collagen, fibronectin, and phosphorylated SMAD2 in pulmonary fibrotic tissues in mice. CONCLUSION: These findings suggest that tranilast inhibits pulmonary fibrosis by suppressing TGFß/SMAD2-mediated ECM protein production, presenting tranilast as a promising and novel anti-fibrotic agent for the treatment of IPF.

Nintedanib inhibits epithelial-mesenchymal transition in A549 alveolar epithelial cells through regulation of the TGF-ß/Smad pathway.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disorder. Recent studies have suggested that epithelial-mesenchymal transition (EMT) of alveolar epithelial cells influences development of pulmonary fibrosis, which is mediated by transforming growth factor ß (TGF-ß). Tumor necrosis factor α (TNF-α), an important proinflammatory cytokine in IPF, has been shown to enhance TGF-ß-induced EMT. Nintedanib, a multiple tyrosine kinase inhibitor that is currently used to treat IPF, has been shown to suppress EMT in various cancer cell lines. However, the mechanism of EMT inhibition by nintedanib and its effect on TGF-ß and TNF-α signaling pathways in alveolar epithelial cells have not been fully elucidated. METHODS: A549 alveolar epithelial cells were stimulated with TGF-ß2 and TNF-α, and the effects of nintedanib on global gene expression were evaluated using microarray analysis. Furthermore, Smad2/3 phosphorylation was assessed using western blotting. RESULTS: We found that in A549 cells, TGF-ß2 and TNF-α treatment induces EMT, which was inhibited by nintedanib. Gene ontology analysis showed that nintedanib significantly attenuates the gene expression of EMT-related cellular pathways and the TGF-ß signaling pathway, but not in the TNF-α-mediated signaling pathway. Furthermore, hierarchical cluster analysis revealed that EMT-related genes were attenuated in nintedanib-treated cells. Additionally, nintedanib was found to markedly suppress phosphorylation of Smad2/3. CONCLUSION: Nintedanib inhibits EMT by mediating EMT-related gene expression and the TGF-ß/Smad pathway in A549 alveolar epithelial cells.

Activation of insulin-like growth factor-1 receptor confers acquired resistance to osimertinib in non-small cell lung cancer with EGFR T790M mutation.

BACKGROUND: Osimertinib (AZD9291) is a third-generation EGFR-tyrosine kinase inhibitor (TKI) that selectively inhibits the activating EGFR mutation and T790M mutation, and is currently used globally to treat EGFR-mutant non-small cell lung cancer (NSCLC). However, acquired resistance to osimertinib is inevitable. METHODS: We established osimertinib-resistant cells (PC9/T790M/AZDR and H1975/AZDR) derived from EGFR-mutant NSCLC cells harboring T790M mutation, and investigated the mechanism of acquired resistance to osimertinib by whole-exome sequencing and multiple phospho-receptor tyrosine kinase (RTK) array. A tumor specimen from an EGFR-mutant NSCLC patient with acquired resistance to osimertinib was also subjected to immunohistochemical analysis. RESULTS: Whole-exome sequencing analysis demonstrated that genetic alterations, such as acquisition of EGFR C797S, loss of T790M mutation, MET amplification, or mutated KRAS, MEK, BRAF, PIK3CA, were not detected. Analysis of phospho-RTK array revealed that insulin-like growth factor-1 receptor (IGF1R) was activated in PC9/T790M/AZDR and H1975/AZDR cells. Knockdown of IGF1R by siRNA as well as inhibition of IGF1R activation by linstinib (IGF1R inhibitor) significantly restored the sensitivity to osimertinib. Immunohistochemical analysis revealed that the expression level of phosphorylated IGF1R was higher in the tumor specimen from the EGFR-mutant NSCLC patient with acquired resistance to osimertinib than in the specimen collected prior to the treatment. CONCLUSIONS: IGF1R activation could occur following treatment with osimertinib in EGFR-mutant NSCLC with T790M mutation, and might be one of the mechanisms underlying osimertinib resistance. Combined treatment of osimertinib and IGF1R inhibitor might be effective in overcoming the acquired resistance to osimertinib induced by IGF1R activation. KEY POINTS: Significant findings of the study: Using osimertinib-resistant cells, we found that IGF1R activation induced by osimertinib treatment in EGFR-mutant NSCLC with T790M mutation is involved in resistance. Increased phosphorylation of IGF1R was observed in the tumor specimen from an EGFR-mutant NSCLC patient with acquired osimertinib resistance. WHAT THIS STUDY ADDS: IGF1R activation might be one of the mechanisms of osimertinib resistance. A combination therapy with osimertinib and an IGF1R inhibitor might be an optimal approach for overcoming the acquired resistance to osimertinib induced by IGF1R activation.

23-valent pneumococcal polysaccharide vaccine improves survival in dialysis patients by preventing cardiac events.

BACKGROUND: Immunodeficient patients are recommended to receive pneumococcal vaccination. However, there is limited evidence showing effectiveness of the polysaccharide vaccine. Polysaccharide vaccination has shown an association with cardiovascular event risk reduction. We assessed the efficacy of the 23-valent pneumococcal polysaccharide vaccine (PPSV23) in relation to the risk of hospitalization and death due to pneumonia and acute cardiac events. METHODS: The medical records of all dialysis patients attending our 8 study centers in 2010 were studied, and we selected 1038 consecutive patients. One-to-one propensity score matching was used to correct for potential selection bias in a PPSV23-vaccinated group versus a non-vaccinated group, and a total of 510 patients were identified for outcome analysis. Time to first admission, or deaths due to all-cause pneumonia or cardiac events until 2015 were compared between both groups. RESULTS: The all-cause death rate was significantly decreased in the PPSV23-vaccinated group, (hazard ratio [HR] 0.62, 95% confidence interval [CI]; 0.46-0.83, P = 0.002). All-cause death was considered to be a competing risk for the other outcomes. Further outcomes were evaluated by competing risk analysis adjusting for mortality. There was no statistically significant difference in the hospitalization rate for pneumonia; however, the hospitalization rate due to cardiac events was significantly lower in the PPSV23-vaccinated group than in the non-vaccinated group (HR 0.44, 95% CI; 0.20-0.96, P = 0.040). There was no statistically significant difference in the death rate due to pneumonia; however, the rate of cardiac death was significantly lower in the PPSV23-vaccinated group than in the non-vaccinated group (HR 0.36, 95% CI; 0.18-0.71, P = 0.003). CONCLUSIONS: The PPSV23 vaccination is associated with a good prognosis and a low-risk of cardiac events in dialysis patients; however, there was no evidence indicating enhanced protective efficacy against pneumonia, suggesting the PPSV23 vaccination might improve the prognosis by directly preventing cardiovascular events.

Role of FBXW7 in the quiescence of gefitinib-resistant lung cancer stem cells in EGFR-mutant non-small cell lung cancer.

Several recent studies suggest that cancer stem cells (CSCs) are involved in intrinsic resistance to cancer treatment. Maintenance of quiescence is crucial for establishing resistance of CSCs to cancer therapeutics. F-box/WD repeat-containing protein 7 (FBXW7) is a ubiquitin ligase that regulates quiescence by targeting the c-MYC protein for ubiquitination. We previously reported that gefitinib-resistant persisters (GRPs) in EGFR-mutant non-small cell lung cancer (NSCLC) cells highly expressed octamer-binding transcription factor 4 (Oct-4) as well as the lung CSC marker CD133, and they exhibited distinctive features of the CSC phenotype. However, the role of FBXW7 in lung CSCs and their resistance to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors in NSCLC is not fully understood. In this study, we developed GRPs from the two NSCLC cell lines PC9 and HCC827, which express an EGFR exon 19 deletion mutation, by treatment with a high concentration of gefitinib. The GRPs from both PC9 and HCC827 cells expressed high levels of CD133 and FBXW7, but low levels of c-MYC. Cell cycle analysis demonstrated that the majority of GRPs existed in the G0/G1 phase. Knockdown of the FBXW7 gene significantly reduced the cell number of CD133-positive GRPs and reversed the cell population in the G0/G1-phase. We also found that FBXW7 expression in CD133-positive cells was increased and c-MYC expression was decreased in gefitinib-resistant tumors of PC9 cells in mice and in 9 out of 14 tumor specimens from EGFR-mutant NSCLC patients with acquired resistance to gefitinib. These findings suggest that FBXW7 plays a pivotal role in the maintenance of quiescence in gefitinib-resistant lung CSCs in EGFR mutation-positive NSCLC.

SETD1A protects from senescence through regulation of the mitotic gene expression program.

SETD1A, a Set1/COMPASS family member maintaining histone-H3-lysine-4 (H3K4) methylation on transcriptionally active promoters, is overexpressed in breast cancer. Here, we show that SETD1A supports mitotic processes and consequentially, its knockdown induces senescence. SETD1A, through promoter H3K4 methylation, regulates several genes orchestrating mitosis and DNA-damage responses, and its depletion causes chromosome misalignment and segregation defects. Cell cycle arrest in SETD1A knockdown senescent cells is independent of mutations in p53, RB and p16, known senescence mediators; instead, it is sustained through transcriptional suppression of SKP2, which degrades p27 and p21. Rare cells escaping senescence by restoring SKP2 expression display genomic instability. In > 200 cancer cell lines and in primary circulating tumor cells, SETD1A expression correlates with genes promoting mitosis and cell cycle suggesting a broad role in suppressing senescence induced by aberrant mitosis. Thus, SETD1A is essential to maintain mitosis and proliferation and its suppression unleashes the tumor suppressive effects of senescence.

Dasatinib Suppresses TGFß-Mediated Epithelial-Mesenchymal Transition in Alveolar Epithelial Cells and Inhibits Pulmonary Fibrosis.

PURPOSE: Transforming growth factor ß (TGFß)-mediated epithelial-mesenchymal transition (EMT) of alveolar epithelial cells contributes to pulmonary fibrosis. Dasatinib (DAS), a potent and broad-spectrum tyrosine kinase inhibitor, has been widely studied as an anti-cancer agent. However, the therapeutic application of DAS for pulmonary fibrosis has not been clarified. Our purpose here is to investigate the effect of DAS on TGFß1-induced EMT in human alveolar and bronchial epithelial cells in vitro and to evaluate the efficacy of DAS on lung fibrosis in vivo. METHODS: TGFß1-stimulated human alveolar epithelial (A549) and bronchial epithelial (BEAS-2B) cells were treated with or without DAS in vitro. Murine pulmonary fibrosis model was generated by injection of bleomycin (BLM). RESULTS: A549 and BEAS-2B cells exposed to TGFß1 underwent EMT, as indicated by downregulation of epithelial protein E-cadherin and induction of the mesenchymal proteins, fibronectin and type I and type IV collagen. These effects were dramatically suppressed by DAS treatment, which also prevented Smad2 and Smad3 phosphorylation. DAS inhibited TGFß1-induced cell motility and migration. Furthermore, DAS administration significantly attenuated lung fibrosis in mice by histological analysis. Treatment with DAS also significantly reduced the levels of collagen and fibronectin and phosphorylation of Smad2 in the lung tissues of the murine model. CONCLUSIONS: These findings suggest that DAS inhibited TGFß-mediated EMT of alveolar and bronchial epithelial cells and attenuated BLM-induced lung fibrosis in mice by suppressing the TGFß/Smad pathway. DAS may be a promising and novel anti-fibrotic agent for preventing lung fibrosis.

LSD1/KDM1 isoform LSD1+8a contributes to neural differentiation in small cell lung cancer.

Small cell lung cancer (SCLC) is an aggressive neuroendocrine tumor characterized by rapid progression. The mechanisms that lead to a shift from initial therapeutic sensitivity to ultimate therapeutic resistance are poorly understood. Although the SCLC genomic landscape led to the discovery of promising agents targeting genetic alterations that were already under investigation, results have been disappointing. Achievements in targeted therapeutics have not been observed for over 30 years. Therefore, the underlying disease biology and novel targets urgently require a better understanding. Epigenetic regulation is deeply involved in the cellular plasticity that could shift tumor cells to the malignant phenotype. We have focused on a histone modifier, LSD1, that is overexpressed in SCLC and is a potent therapeutic target. Interestingly, the LSD1 splice variant LSD1+8a, the expression of which has been reported to be restricted to neural tissue, was detected and was involved in the expression of neuroendocrine marker genes in SCLC cell lines. Cells with high expression of LSD1+8a were resistant to CDDP and LSD1 inhibitor. Moreover, suppression of LSD1+8a inhibited cell proliferation, indicating that LSD1+8a could play a critical role in SCLC. These findings suggest that LSD1+8a should be considered a novel therapeutic target in SCLC.

Surfactant protein-D predicts prognosis of interstitial lung disease induced by anticancer agents in advanced lung cancer: a case control study.

BACKGROUND: Interstitial lung diseases induced by anticancer agents (ILD-AA) are rare adverse effects of anticancer therapy. However, prognostic biomarkers for ILD-AA have not been identified in patients with advanced lung cancer. Our aim was to analyze the association between serum biomarkers sialylated carbohydrate antigen Krebs von den Lungen-6 (KL-6) and surfactant protein D (SP-D), and clinical characteristics in patients diagnosed with ILD-AA. METHODS: Between April 2011 and March 2016, 1224 advanced lung cancer patients received cytotoxic agents and epidermal growth factor receptor tyrosine kinase inhibitors at Juntendo University Hospital and Juntendo University Urayasu Hospital. Of these patients, those diagnosed with ILD-AA were enrolled in this case control study. ΔKL-6 and ΔSP-D were defined as the difference between the levels at the onset of ILD-AA and their respective levels prior to development of ILD-AA. We evaluated KL-6 and SP-D at the onset of ILD-AA, ΔKL-6 and ΔSP-D, the risk factors for death related to ILD-AA, the chest high resolution computed tomography (HRCT) findings, and survival time in patients diagnosed with ILD-AA. RESULTS: Thirty-six patients diagnosed with ILD-AA were enrolled in this study. Among them, 14 patients died of ILD-AA. ΔSP-D in the patients who died was significantly higher than that in the patients who survived. However, ΔKL-6 did not differ significantly between the two groups. Moreover, ΔSP-D in patients who exhibited diffuse alveolar damage was significantly higher than that in the other patterns on HRCT. Receiver operating characteristic curve analysis was used to set the optimal cut off value for ΔSP-D at 398 ng/mL. Survival time for patients with high ΔSP-D (≥ 398 ng/mL) was significantly shorter than that for patients with low ΔSP-D. Multivariate analysis revealed that ΔSP-D was a significant prognostic factor of ILD-AA. CONCLUSIONS: This is the first research to evaluate high ΔSP-D (≥ 398 ng/mL) in patients with ILD-AA and to determine the risk factors for ILD-AA in advanced lung cancer patients. ΔSP-D might be a serum prognostic biomarker of ILD-AA. Clinicians should evaluate serum SP-D during chemotherapy and should carefully monitor the clinical course in patients with high ΔSP-D.

Genomic Instability Is Induced by Persistent Proliferation of Cells Undergoing Epithelial-to-Mesenchymal Transition.

TGF-ß secreted by tumor stroma induces epithelial-to-mesenchymal transition (EMT) in cancer cells, a reversible phenotype linked to cancer progression and drug resistance. However, exposure to stromal signals may also lead to heritable changes in cancer cells, which are poorly understood. We show that epithelial cells failing to undergo proliferation arrest during TGF-ß-induced EMT sustain mitotic abnormalities due to failed cytokinesis, resulting in aneuploidy. This genomic instability is associated with the suppression of multiple nuclear envelope proteins implicated in mitotic regulation and is phenocopied by modulating the expression of LaminB1. While TGF-ß-induced mitotic defects in proliferating cells are reversible upon its withdrawal, the acquired genomic abnormalities persist, leading to increased tumorigenic phenotypes. In metastatic breast cancer patients, increased mesenchymal marker expression within single circulating tumor cells is correlated with genomic instability. These observations identify a mechanism whereby microenvironment-derived signals trigger heritable genetic changes within cancer cells, contributing to tumor evolution.

Autofluorescence imaging bronchoscopy as a novel approach to the management of tracheobronchopathia osteochondroplastica: a case report.

Tracheobronchopathia osteochondroplastica (TO) is not only rare but also presents highly varied and unpredictable clinical manifestations. Consequently, the management and treatment strategies remain unclear. An accurate evaluation tool is important for the management of individual patients in the absence of standard guidelines. Although bronchoscopy is the gold standard for diagnosis, it cannot satisfactorily detect the treatment response and disease progression because subtle mucosal changes can go undetected. Therefore, improved techniques that can detect subtle mucosal changes associated with TO are desirable. Autofluorescence imaging bronchoscopy (AFI) is a recently introduced advanced endoscopic technology that can detect subtle mucosal changes with the aid of different colors. Here we report the first case, to the best of our knowledge, involving a 42-year-old man with TO in whom tracheal involvement was evaluated by AFI and detected as the appearance of a magenta color.

Oct4 plays a crucial role in the maintenance of gefitinib-resistant lung cancer stem cells.

Several recent studies have suggested that cancer stem cells (CSCs) are involved in resistance to gefitinib in non-small cell lung cancer (NSCLC). Oct4, a member of the POU-domain transcription factor family, has been shown to be involved in CSC properties of various cancers. We previously reported that Oct4 and the putative lung CSC marker CD133 were highly expressed in gefitinib-resistant persisters (GRPs) in NSCLC cells, and GRPs exhibited characteristic features of the CSCs phenotype. The aim of this study was to elucidate the role of Oct4 in the resistance to gefitinib in NSCLC cells with an activating epidermal growth factor receptor (EGFR) mutation. NSCLC cell lines, PC9, which express the EGFR exon 19 deletion mutation, were transplanted into NOG mice, and were treated with gefitinib in vivo. After 14-17 days of gefitinib treatment, the tumors still remained; these tumors were referred to as gefitinib-resistant tumors (GRTs). PC9-GRTs showed higher expression of Oct4 and CD133. To investigate the role of Oct4 in the maintenance of gefitinib-resistant lung CSCs, we introduced the Oct4 gene into PC9 and HCC827 cells carrying an activating EGFR mutation by lentiviral infection. Transfection of Oct4 significantly increased CD133-positive GRPs and the number of sphere formation, reflecting the self-renewal activity, of PC9 and HCC827 cells under the high concentration of gefitinib in vitro. Furthermore, Oct4-overexpressing PC9 cells (PC9-Oct4) significantly formed tumors at 1 × 10 cells/injection in NOG mice as compared to control cells. In addition, PC9-Oct4 tumors were more resistant to gefitinib treatment as compared to control cells in vivo. Finally, immunohistochemical analysis revealed that Oct4 was highly expressed in tumor specimens of EGFR-mutant NSCLC patients with acquired resistance to gefitinib. Collectively, these findings suggest that Oct4 plays a pivotal role in the maintenance of lung CSCs resistant to gefitinib in EGFR mutation-positive NSCLC.