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.

Challenges on tuberculosis care in health care facilities during COVID-19 pandemic: Indonesian perspective.

Indonesia is among the top three countries globally with the highest tuberculosis burden. During the past decades, Indonesian health authorities have struggled to improve tuberculosis care quality in health care facilities by optimizing the regulation and strengthening the private sector contributions. The coronavirus disease 2019 (COVID-19) pandemic has hardly affected the Indonesian health care system, including the National Tuberculosis Control Program. While the end of the COVID-19 pandemic in Indonesia is uncertain, the measure to control tuberculosis must not be weakened. Early identification and measurement of the problem size are essential to decide the most appropriate approach to maintain the sustainability of National Tuberculosis Control Program, particularly in health care facilities during the COVID-19 pandemic. This article points out the possible threats to the sustainability of TB care in Indonesia during the COVID-19 pandemic, including some approaches to overcome those problems.

Lung Fibrosis Sequelae After Recovery from COVID-19 Infection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus that causes coronavirus diseases 2019 (COVID-19). The SARS-CoV-2 is very contagious and nobody is known to be immune to it. The post-infected lung would leave a scar known as fibrosis, a scar tissue. A study from Wuhan, China suggested the development of fibrosis, though it was too early to label these lung changes as irreversible fibrosis in a time range of 3 weeks. The occurrence of fibrosis indicates a chronic infection which greatly contributes to the hallmark symptom of COVID-19 induced ARDS such as shortness of breath and chest pain. However, many of those studies have not yet explained the condition of the patient's lung after total recovery from the COVID-19. This report demonstrates the clinical symptoms, chest CT scan, spirometry, and blood gas analysis of patient after total recovery from the COVID-19 with appearance lung fibrosis.

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.

Cancer-associated fibroblast migration in non-small cell lung cancers is modulated by increased integrin α11 expression.

Cancer-associated fibroblasts (CAFs) regulate cancer progression through the modulation of extracellular matrix (ECM) and cancer cell adhesion. While undergoing a series of phenotypic changes, CAFs control cancer-stroma interactions through integrin receptor signaling. Here, we isolated CAFs from patients with non-small-cell lung cancer (NSCLC) and examined their gene expression profiles. We identified collagen type XI α1 (COL11A1), integrin α11 (ITGA11), and the ITGA11 major ligand collagen type I α1 (COL1A1) among the 390 genes that were significantly enriched in NSCLC-associated CAFs. Increased ITGA11 expression in cancer stroma was correlated with a poor clinical outcome in patients with NSCLC. Increased expression of fibronectin and collagen type I induced ITGA11 expression in CAFs. The cellular migration of CAFs toward collagen type I and fibronectin was promoted via ERK1/2 signaling, independently of the fibronectin receptor integrin α5ß1. Additionally, ERK1/2 signaling induced ITGA11 and COL11A1 expression in cancer stroma. We, therefore, propose that targeting ITGA11 and COL11A1 expressing CAFs to block cancer-stroma interactions may serve as a novel, promising anti-tumor strategy.

The use of indoor plant as an alternative strategy to improve indoor air quality in Indonesia.

Indoor air pollution marked with decreased air quality below the set standard. The quality of indoor air is determined by ambient air quality as well as by a harmful substance resulting from the household activity. Indoor air pollution may cause several problems such as sick building syndrome, chronic obstructive pulmonary disease (COPD), asthma, lung cancer, and is responsible for nearly two million death in developing countries. One of the interesting research topics to overcome the indoor air pollution problem is the application of indoor plants. Although there are no established criteria to specify the best indoor plant, several studies have revealed the capability of a particular indoor plant to remove the harmful substances. This paper summarizes important information about indoor air pollution and provides the evidence-based insight of indoor plant usefulness as an alternative way for indoor air remediation.

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.

Pirfenidone attenuates lung fibrotic fibroblast responses to transforming growth factor-ß1.

BACKGROUND: Pirfenidone, an antifibrotic agent used for the treatment of idiopathic pulmonary fibrosis (IPF), functions by inhibiting myofibroblast differentiation, which is involved in transforming growth factor (TGF)-ß1-induced IPF pathogenesis. However, unlike normal lung fibroblasts, the relationship between pirfenidone responses of TGF-ß1-induced human fibrotic lung fibroblasts and lung fibrosis has not been elucidated. METHODS: The effects of pirfenidone were evaluated in lung fibroblasts isolated from fibrotic human lung tissues after TGF-ß1 exposure. The ability of two new pharmacological targets of pirfenidone, collagen triple helix repeat containing protein 1(CTHRC1) and four-and-a-half LIM domain protein 2 (FHL2), to mediate contraction of collagen gels and migration toward fibronectin were assessed in vitro. RESULTS: Compared to control lung fibroblasts, pirfenidone significantly restored TGF-ß1-stimulated fibroblast-mediated collagen gel contraction, migration, and CTHRC1 release in lung fibrotic fibroblasts. Furthermore, pirfenidone attenuated TGF-ß1- and CTHRC1-induced fibroblast activity, upregulation of bone morphogenic protein-4(BMP-4)/Gremlin1, and downregulation of α-smooth muscle actin, fibronectin, and FHL2, similar to that observed post-CTHRC1 inhibition. In contrast, FHL2 inhibition suppressed migration and fibronectin expression, but did not downregulate CTHRC1. CONCLUSIONS: Overall, pirfenidone suppressed fibrotic fibroblast-mediated fibrotic processes via inverse regulation of CTHRC1-induced lung fibroblast activity. Thus, CTHRC1 can be used for predicting pirfenidone response and developing new therapeutic targets for lung fibrosis.

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.

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.

CD44 silencing decreases the expression of stem cell-related factors induced by transforming growth factor ß1 and tumor necrosis factor α in lung cancer: Preliminary findings.

The mechanism underlying increased concentrations of cancer stem cell (CSC)-associated factors in non-small cell lung cancer (NSCLC) cells treated with transforming growth factor ß1 (TGFß1) and tumor necrosis factor α (TNFα), is still not clear. The purpose of this study was to investigate the possible role of CD44 in the regulation of CSC-associated genes, by analyzing the effect of CD44 knockdown on their expression. A549, a NSCLC cell line that expresses CD44 antigen, was treated with TGFß1 and TNFα. Small-interfering ribonucleic acid (siRNA) that specifically targets the CD44 gene was used to knockdown the expression of CD44 in A549. The gene expressions of CD44, CXCR4, POU5F1 (octamer-binding transcription factor 4 [Oct4]), PROM1, NANOG, c-Myc, KLF4, and SOX2, as well as of CDH1 (E-cadherin), CDH2 (N-cadherin), VIM (vimentin), and FN1 (fibronectin) were analyzed in A549 cells by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Cell morphology was observed using light microscopy. After TGFß1/TNFα treatment, increased expressions of CXCR4 and POU5F1 were detected. Silencing of CD44 gene expression was confirmed by RT-qPCR. The knockdown of CD44 decreased the CXCR4 and POU5F1 gene expressions in TGFß1/TNFα-treated A549 cells. However, the silencing of CD44 did not affect the morphology of TGFß1/TNFα-treated A549 cells nor it reversed epithelial-mesenchymal transition (EMT) gene signature induced by TGFß1/TNFα in A549 cells. Our preliminary findings suggest that the CD44 gene may have a role in regulating CXCR4 and POU5F1 gene expressions, independently of the EMT signaling pathway.

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.

Strategies for an effective tobacco harm reduction policy in Indonesia.

Tobacco consumption is a major causative agent for various deadly diseases such as coronary artery disease and cancer. It is the largest avoidable health risk in the world, causing more problems than alcohol, drug use, high blood pressure, excess body weight or high cholesterol. As countries like Indonesia prepare to develop national policy guidelines for tobacco harm reduction, the scientific community can help by providing continuous ideas and a forum for sharing and distributing information, drafting guidelines, reviewing best practices, raising funds, and establishing partnerships. We propose several strategies for reducing tobacco consumption, including advertisement interference, cigarette pricing policy, adolescent smoking prevention policy, support for smoking cessation therapy, special informed consent for smokers, smoking prohibition in public spaces, career incentives, economic incentives, and advertisement incentives. We hope that these strategies would assist people to avoid starting smoking or in smoking cessation.

Treatment with insulin-like growth factor 1 receptor inhibitor reverses hypoxia-induced epithelial-mesenchymal transition in non-small cell lung cancer.

Insulin-like growth factor 1 receptor (IGF1R) is expressed in many types of solid tumors including non-small cell lung cancer (NSCLC), and enhanced activation of IGF1R is thought to reflect cancer progression. Epithelial-mesenchymal transition (EMT) has been established as one of the mechanisms responsible for cancer progression and metastasis, and microenvironment conditions, such as hypoxia, have been shown to induce EMT. The purposes of this study were to address the role of IGF1R activation in hypoxia-induced EMT in NSCLC and to determine whether inhibition of IGF1R might reverse hypoxia-induced EMT. Human NSCLC cell lines A549 and HCC2935 were exposed to hypoxia to investigate the expression of EMT-related genes and phenotypes. Gene expression analysis was performed by quantitative real-time PCR and cell phenotypes were studied by morphology assessment, scratch wound assay, and immunofluorescence. Hypoxia-exposed cells exhibited a spindle-shaped morphology with increased cell motility reminiscent of EMT, and demonstrated the loss of E-cadherin and increased expression of fibronectin and vimentin. Hypoxia also led to increased expression of IGF1, IGF binding protein-3 (IGFBP3), and IGF1R, but not transforming growth factor ß1 (TGFß1). Inhibition of hypoxia-inducible factor 1α (HIF1α) with YC-1 abrogated activation of IGF1R, and reduced IGF1 and IGFBP3 expression in hypoxic cells. Furthermore, inhibition of IGF1R using AEW541 in hypoxic condition restored E-cadherin expression, and reduced expression of fibronectin and vimentin. Finally, IGF1 stimulation of normoxic cells induced EMT. Our findings indicated that hypoxia induced EMT in NSCLC cells through activation of IGF1R, and that IGF1R inhibition reversed these phenomena. These results suggest a potential role for targeting IGF1R in the prevention of hypoxia-induced cancer progression and metastasis mediated by EMT.