Interaction between non-small-cell lung cancer cells and fibroblasts via enhancement of TGF-β signaling by IL-6. Lung Cancer. 2013;82:204-213. [PMID: 24011634 DOI: 10.1016/j.lungcan.2013.08.008]

Boosting immune responses in lung tumor immune microenvironment: A comprehensive review of strategies and adjuvants

The immune system has a substantial impact on the growth and expansion of lung malignancies. Immune cells are encompassed by a stroma comprising an extracellular matrix (ECM) and different cells like stromal cells, which are known as the tumor immune microenvironment (TIME). TME is marked by the presence of immunosuppressive factors, which inhibit the function of immune cells and expand tumor growth. In recent years, numerous strategies and adjuvants have been developed to extend immune responses in the TIME, to improve the efficacy of immunotherapy. In this comprehensive review, we outline the present knowledge of immune evasion mechanisms in lung TIME, explain the biology of immune cells and diverse effectors on these components, and discuss various approaches for overcoming suppressive barriers. We highlight the potential of novel adjuvants, including toll-like receptor (TLR) agonists, cytokines, phytochemicals, nanocarriers, and oncolytic viruses, for enhancing immune responses in the TME. Ultimately, we provide a summary of ongoing clinical trials investigating these strategies and adjuvants in lung cancer patients. This review also provides a broad overview of the current state-of-the-art in boosting immune responses in the TIME and highlights the potential of these approaches for improving outcomes in lung cancer patients.

Interleukin-6 in Hepatocellular Carcinoma: A Dualistic Point of View

Hepatocellular Carcinoma (HCC) is a pressing health concern, demanding a deep understanding of various mediators' roles in its development for therapeutic progress. Notably, interleukin-6 (IL-6) has taken center stage in investigations due to its intricate and context-dependent functions. This review delves into the dual nature of IL-6 in HCC, exploring its seemingly contradictory roles as both a promoter and an inhibitor of disease progression. We dissect the pro-tumorigenic effects of IL-6, including its impact on tumor growth, angiogenesis, and metastasis. Concurrently, we examine its anti-tumorigenic attributes, such as its role in immune response activation, cellular senescence induction, and tumor surveillance. Through a comprehensive exploration of the intricate interactions between IL-6 and the tumor microenvironment, this review highlights the need for a nuanced comprehension of IL-6 signaling in HCC. It underscores the importance of tailored therapeutic strategies that consider the dynamic stages and diverse surroundings within the tumor microenvironment. Future research directions aimed at unraveling the multifaceted mechanisms of IL-6 in HCC hold promise for developing more effective treatment strategies and improving patient outcomes.

Chemotherapy-induced metastasis: molecular mechanisms and clinical therapies

Chemotherapy, the most widely accepted treatment for malignant tumors, is dependent on cell death induced by various drugs including antimetabolites, alkylating agents, mitotic spindle inhibitors, antitumor antibiotics, and hormonal anticancer drugs. In addition to causing side effects due to non-selective cytotoxicity, chemotherapeutic drugs can initiate and promote metastasis, which greatly reduces their clinical efficacy. The knowledge of how they induce metastasis is essential for developing strategies that improve the outcomes of chemotherapy. Herein, we summarize the recent findings on chemotherapy-induced metastasis and discuss the underlying mechanisms including tumor-initiating cell expansion, the epithelial-mesenchymal transition, extracellular vesicle involvement, and tumor microenvironment alterations. In addition, the use of combination treatments to overcome chemotherapy-induced metastasis is also elaborated.

A 3D culture system for evaluating the combined effects of cisplatin and anti-fibrotic drugs on the growth and invasion of lung cancer cells co-cultured with fibroblasts

Fibrosis and fibroblast activation usually occur in the tissues surrounding a malignant tumor; therefore, anti-fibrotic drugs are used in addition to chemotherapy. A reliable technique for evaluating the combined effects of anti-fibrotic drugs and anticancer drugs would be beneficial for the development of an appropriate treatment strategy. In this study, we manufactured a three-dimensional (3D) co-culture system of fibroblasts and lung cancer cell spheroids in Matrigel supplemented with fibrin (fibrin/Matrigel) that simulated the tissue microenvironment around a solid tumor. We compared the efficacy of an anticancer drug (cisplatin) with or without pretreatments of two anti-fibrotic drugs, nintedanib and pirfenidone, on the growth and invasion of cancer cells co-cultured with fibroblasts. The results showed that the addition of nintedanib improved cisplatin's effects on suppressing the growth of cancer cell spheroids and the invasion of cancer cells. In contrast, pirfenidone did not enhance the anticancer activity of cisplatin. Nintedanib also showed higher efficacy than pirfenidone in reducing the expression of four genes in fibroblasts associated with cell adhesion, invasion, and extracellular matrix degradation. This study demonstrated that the 3D co-cultures in fibrin/Matrigel would be useful for assessing the effects of drug combinations on tumor growth and invasion.

Therapeutic Targeting of Cancer-Associated Fibroblasts in the Non-Small Cell Lung Cancer Tumor Microenvironment

Lung cancer is the most frequently diagnosed cancer and the leading cause of cancer death worldwide. The most common lung cancer is non-small cell lung cancer (NSCLC), with an overall 5-year survival rate of around 20% because NSCLC is a metastatic disease. A better understanding of the mechanism underlying lung cancer metastasis is therefore urgently needed. The tumor microenvironment involves different types of stromal cells and functions as key components in the progression of NSCLC. Through epithelial-mesenchymal transition (EMT), in which epithelial cells lose their polarity and acquire mesenchymal potential, cancer cells acquire metastatic abilities, as well as cancer stem-cell-like potential. We previously reported that cancer-associated fibroblasts (CAFs) interact with lung cancer cells to allow for the acquisition of malignancy and treatment resistance by paracrine loops via EMT signals in the tumor microenvironment. Furthermore, CAFs regulate the cytotoxic activity of immune cells via various cytokines and chemokines, creating a microenvironment of immune tolerance. Regulation of CAFs can therefore affect immune responses. Recent research has shown several roles of CAFs in NSCLC tumorigenesis, owing to their heterogeneity, so molecular markers of CAFs should be elucidated to better classify tumor-promoting subtypes and facilitate the establishment of CAF-specific targeted therapies. CAF-targeted cancer treatments may suppress EMT and regulate the niche of cancer stem cells and the immunosuppressive network and thus may prove useful for NSCLC treatment through multiple mechanisms.

The Role of IL-6 in Cancer Cell Invasiveness and Metastasis-Overview and Therapeutic Opportunities

Interleukin 6 (IL-6) belongs to a broad class of cytokines involved in the regulation of various homeostatic and pathological processes. These activities range from regulating embryonic development, wound healing and ageing, inflammation, and immunity, including COVID-19. In this review, we summarise the role of IL-6 signalling pathways in cancer biology, with particular emphasis on cancer cell invasiveness and metastasis formation. Targeting principal components of IL-6 signalling (e.g., IL-6Rs, gp130, STAT3, NF-κB) is an intensively studied approach in preclinical cancer research. It is of significant translational potential; numerous studies strongly imply the remarkable potential of IL-6 signalling inhibitors, especially in metastasis suppression.

Cancer-associated fibroblasts in nonsmall cell lung cancer: From molecular mechanisms to clinical implications

Lung cancer is the common and leading cause of cancer death worldwide. The tumor microenvironment has been recognized to be instrumental in tumorigenesis. To have a deep understanding of the molecular mechanism of nonsmall cell lung carcinoma (NSCLC), cancer-associated fibroblasts (CAFs) have gained increasing research interests. CAFs belong to the crucial and dominant cell population in the tumor microenvironment to support the cancer cells. The interplay and partnership between cancer cells and CAFs contribute to each stage of tumorigenesis. CAFs exhibit prominent heterogeneity and secrete different kinds of cytokines and chemokines, growth factors and extracellular matrix proteins involved in cancer cell proliferation, invasion, metastasis and chemoresistance. Many studies focused on the protumorigenic functions of CAFs, yet many challenges about the heterogeneity of CAFS remain unresolved. This review comprehensively summarized the tumor-promoting role and molecular mechanisms of CAFs in NSCLC, including their origin, phenotypic changes and heterogeneity and their functional roles in carcinogenesis. Meanwhile, we also highlighted the updated molecular classifications based on the molecular features and functional roles of CAFs. With the development of cutting-edge platforms and further investigations of CAFs, novel therapeutic strategies for accurately targeting CAFs in NSCLC may be developed based on the increased understanding of the relevant molecular mechanisms.

COVID-19 vs. Cancer Immunosurveillance: A Game of Thrones within an Inflamed Microenviroment

The COVID-19 pandemic accounts for more than 500 million confirmed infections and over 6 million deaths worldwide in the last 2 years. SARS-CoV-2 causes a highly complex form of inflammation that affects the human organism both acutely and chronically. In the same line, cancer as an inflammation-induced and immune-editing disease appears to cross-react with immune system at different levels including early interactions during carcinogenesis and later cross-talks within the tumor microenvironment. With all that in mind, a reasonable question one might address is whether the SARS-CoV-2 infection and the derived "long lasting inflammatory status" that is frequently observed in patients, might affect the cancer immunosurveillance mechanisms and consequently their risk of developing cancer, as well as the tumor and immune cell behaviors within the inflamed microenvironment. On this context, this review intends to outline and discuss the existing knowledge on SARS-CoV-2-mediated immunomodulation under the prism of changes that might be able to interfere with cancer cell immunoescape and the overall tumor progression and response to conventional therapeutics. Our goal is to highlight a potential interplay between the COVID-19 immunopathology and cancer immune-microenvironment that may pave the way for thorough investigation in the future.

Collagen 3D matrices as a model for the study of cell behavior in pulmonary fibrosis

Purpose: Idiopathic pulmonary fibrosis (IPF) is a complex progressive chronic lung disease where epithelial to mesenchymal interaction, extracellular matrix (ECM) contact, and pro-fibrotic cytokines dynamics take part in the development of the disease. The study of IPF in the widespread in vitro two-dimensional (2 D) culture fails to explain the interaction of cells with the changing environment that occurs in fibrotic lung tissue. A three-dimensional (3 D) co-culture model might shed light on the pathogenesis of IPF by mimicking the fibrotic environment. Materials and Methods: Fibroblasts from nine IPF were isolated and embedded in collagen matrices with the alveolar epithelial human cell line (A549) on the top. Cells were also cultured in 2 D with and without TGF-β1 as a conventional model to compare with. Both types of cells were isolated separately. Protein and gene expression of the main fibrotic markers were measured by qPCR, Western blot, and ELISA. Results: IPF fibroblasts to myofibroblasts differentiation was observed in the 3 D model and in cells stimulated with TGF-β1. In addition, ECM-related genes were highly up-regulated in the 3 D collagen matrix. A549 co-cultured 3 D with IPF fibroblasts showed EMT activation, with down-regulation of E-cadherin (CDH1). However, other pro-fibrotic genes as VIM, TGFB1, and MMP7 were up-regulated in A549 co-cultured 3 D with fibroblasts. Conclusions: 3 D-collagen matrices might induce fibroblasts' fibrotic phenotype as in the classic TGF-β1 model, by up-regulating genes associated with matrix production. In addition, IPF lung fibroblasts seem to exert a pro-fibrotic influence in A549 cells when they are co-cultured. These results suggest that an improved 3 D co-culture model might serve as an important tool to study the fibrotic process and its regulation.

Biomedical Applications of Non-Small Cell Lung Cancer Spheroids

Lung malignancies accounted for 11% of cancers worldwide in 2020 and remained the leading cause of cancer deaths. About 80% of lung cancers belong to non-small cell lung cancer (NSCLC), which is characterized by extremely high clonal and morphological heterogeneity of tumors and development of multidrug resistance. The improvement of current therapeutic strategies includes several directions. First, increasing knowledge in cancer biology results in better understanding of the mechanisms underlying malignant transformation, alterations in signal transduction, and crosstalk between cancer cells and the tumor microenvironment, including immune cells. In turn, it leads to the discovery of important molecular targets in cancer development, which might be affected pharmaceutically. The second direction focuses on the screening of novel drug candidates, synthetic or from natural sources. Finally, "personalization" of a therapeutic strategy enables maximal damage to the tumor of a patient. The personalization of treatment can be based on the drug screening performed using patient-derived tumor xenografts or in vitro patient-derived cell models. 3D multicellular cancer spheroids, generated from cancer cell lines or tumor-isolated cells, seem to be a helpful tool for the improvement of current NSCLC therapies. Spheroids are used as a tumor-mimicking in vitro model for screening of novel drugs, analysis of intercellular interactions, and oncogenic cell signaling. Moreover, several studies with tumor-derived spheroids suggest this model for the choice of "personalized" therapy. Here we aim to give an overview of the different applications of NSCLC spheroids and discuss the potential contribution of the spheroid model to the development of anticancer strategies.

ERK5 modulates IL-6 secretion and contributes to tumor-induced immune suppression

Tumors exhibit a variety of strategies to dampen antitumor immune responses. With an aim to identify factors that are secreted from tumor cells, we performed an unbiased mass spectrometry-based secretome analysis in lung cancer cells. Interleukin-6 (IL-6) has been identified as a prominent factor secreted by tumor cells and cancer-associated fibroblasts isolated from cancer patients. Incubation of dendritic cell (DC) cultures with tumor cell supernatants inhibited the production of IL-12p70 in DCs but not the surface expression of other activation markers which is reversed by treatment with IL-6 antibody. Defects in IL-12p70 production in the DCs inhibited the differentiation of Th1 but not Th2 and Th17 cells from naïve CD4⁺ T cells. We also demonstrate that the classical mitogen-activated protein kinase, ERK5/MAPK7, is required for IL-6 production in tumor cells. Inhibition of ERK5 activity or depletion of ERK5 prevented IL-6 production in tumor cells, which could be exploited for enhancing antitumor immune responses.

Role of glutamine and its metabolite ammonia in crosstalk of cancer-associated fibroblasts and cancer cells

Cancer-associated fibroblasts (CAFs), the most abundant cells in the tumor microenvironment, play an indispensable role in cancer initiation, progression, metastasis, and metabolism. The limitations of traditional treatments can be partly attributed to the lack of understanding of the role of the tumor stroma. For this reason, CAF targeting is gradually gaining attention, and many studies are trying to overcome the limitations of tumor treatment with CAF as a breakthrough. Glutamine (GLN) has been called a “nitrogen reservoir” for cancer cells because of its role in supporting anabolic processes such as fuel proliferation and nucleotide synthesis, but ammonia is a byproduct of the metabolism of GLN and other nitrogenous compounds. Moreover, in some studies, GLN has been reported as a fundamental nitrogen source that can support tumor biomass. In this review, we discuss the latest findings on the role of GLN and ammonia in the crosstalk between CAFs and cancer cells as well as the potential therapeutic implications of nitrogen metabolism.

Tumor-Induced Inflammatory Cytokines and the Emerging Diagnostic Devices for Cancer Detection and Prognosis

Chronic inflammation generated by the tumor microenvironment is known to drive cancer initiation, proliferation, progression, metastasis, and therapeutic resistance. The tumor microenvironment promotes the secretion of diverse cytokines, in different types and stages of cancers. These cytokines may inhibit tumor development but alternatively may contribute to chronic inflammation that supports tumor growth in both autocrine and paracrine manners and have been linked to poor cancer outcomes. Such distinct sets of cytokines from the tumor microenvironment can be detected in the circulation and are thus potentially useful as biomarkers to detect cancers, predict disease outcomes and manage therapeutic choices. Indeed, analyses of circulating cytokines in combination with cancer-specific biomarkers have been proposed to simplify and improve cancer detection and prognosis, especially from minimally-invasive liquid biopsies, such as blood. Additionally, the cytokine signaling signatures of the peripheral immune cells, even from patients with localized tumors, are recently found altered in cancer, and may also prove applicable as cancer biomarkers. Here we review cytokines induced by the tumor microenvironment, their roles in various stages of cancer development, and their potential use in diagnostics and prognostics. We further discuss the established and emerging diagnostic approaches that can be used to detect cancers from liquid biopsies, and additionally the technological advancement required for their use in clinical settings.

Cancer drug resistance induced by EMT: novel therapeutic strategies

Over the last decade, important clinical benefits have been achieved in cancer patients by using drug-targeting strategies. Nevertheless, drug resistance is still a major problem in most cancer therapies. Epithelial-mesenchymal plasticity (EMP) and tumour microenvironment have been described as limiting factors for effective treatment in many cancer types. Moreover, epithelial-to-mesenchymal transition (EMT) has also been associated with therapy resistance in many different preclinical models, although limited evidence has been obtained from clinical studies and clinical samples. In this review, we particularly deepen into the mechanisms of which intermediate epithelial/mesenchymal (E/M) states and its interconnection to microenvironment influence therapy resistance. We also describe how the use of bioinformatics and pharmacogenomics will help to figure out the biological impact of the EMT on drug resistance and to develop novel pharmacological approaches in the future.

Extracellular Vesicle Mediated Tumor-Stromal Crosstalk Within an Engineered Lung Cancer Model

Tumor-stromal interactions within the tumor microenvironment (TME) influence lung cancer progression and response to therapeutic interventions, yet traditional in vitro studies fail to replicate the complexity of these interactions. Herein, we developed three-dimensional (3D) lung tumor models that mimic the human TME and demonstrate tumor-stromal crosstalk mediated by extracellular vesicles (EVs). EVs released by tumor cells, independent of p53 status, and fibroblasts within the TME mediate immunomodulatory effects; specifically, monocyte/macrophage polarization to a tumor-promoting M2 phenotype within this 3D-TME. Additionally, immune checkpoint inhibition in a 3D model that included T cells showed an inhibition of tumor growth and reduced hypoxia within the TME. Thus, perfused 3D tumor models incorporating diverse cell types provide novel insights into EV-mediated tumor-immune interactions and immune-modulation for existing and emerging cancer therapies.

The emerging role of miRNA in the perturbation of tumor immune microenvironment in chemoresistance: Therapeutic implications

Chemoresistance is a major hindrance in cancer chemotherapies, a leading cause of tumor recurrence and cancer-related deaths. Cancer cells develop numerous strategies to elude immune attacks and are regulated by immunological factors. Cancer cells can alter the expression of several immune modulators to upregulate the activities of immune checkpoint pathways. Targeting the immune checkpoint inhibitors is a part of the cancer immunotherapy altered during carcinogenesis. These immune modulators have the capability to reprogram the tumor microenvironment, thereby change the efficacy of chemotherapeutics. In general, the sensitivity of drugs is reduced in the immunosuppressive tumor microenvironment, resulting in chemoresistance and tumor relapse. The regulation of microRNAs (miRNAs) is well established in cancer initiation, progression, and therapy. Intriguingly, miRNA affects cancer immune surveillance and immune response by targeting immune checkpoint inhibitors in the tumor microenvironment. miRNAs alter the gene expression at the post-transcriptional level, which modulates both innate and adaptive immune systems. Alteration of tumor immune microenvironment influences drug sensitivity towards cancer cells. Besides, the expression profile of immune-modulatory miRNAs can be used as a potential biomarker to predict the response and clinical outcomes in cancer immunotherapy and chemotherapy. Recent evidences have revealed that cancer-derived immune-modulatory miRNAs might be promising targets to counteract cancer immune escape, thereby increasing drug efficacy. In this review, we have compiled the role of miRNAs in overcoming the chemoresistance by modulating tumor microenvironment and discussed their preclinical and clinical implications.

Fibroblast activation protein targeted near infrared photoimmunotherapy (NIR PIT) overcomes therapeutic resistance in human esophageal cancer

Cancer-associated fibroblasts (CAFs) have an important role in the tumor microenvironment. CAFs have the multifunctionality which strongly support cancer progression and the acquisition of therapeutic resistance by cancer cells. Near-infrared photoimmunotherapy (NIR-PIT) is a novel cancer treatment that uses a highly selective monoclonal antibody (mAb)-photosensitizer conjugate. We developed fibroblast activation protein (FAP)-targeted NIR-PIT, in which IR700 was conjugated to a FAP-specific antibody to target CAFs (CAFs-targeted NIR-PIT: CAFs-PIT). Thus, we hypothesized that the control of CAFs could overcome the resistance to conventional chemotherapy in esophageal cancer (EC). In this study, we evaluated whether EC cell acquisition of stronger malignant characteristics and refractoriness to chemoradiotherapy are mediated by CAFs. Next, we assessed whether the resistance could be rescued by eliminating CAF stimulation by CAFs-PIT in vitro and in vivo. Cancer cells acquired chemoradiotherapy resistance via CAF stimulation in vitro and 5-fluorouracil (FU) resistance in CAF-coinoculated tumor models in vivo. CAF stimulation promoted the migration/invasion of cancer cells and a stem-like phenotype in vitro, which were rescued by elimination of CAF stimulation. CAFs-PIT had a highly selective effect on CAFs in vitro. Finally, CAF elimination by CAFs-PIT in vivo demonstrated that the combination of 5-FU and NIR-PIT succeeded in producing 70.9% tumor reduction, while 5-FU alone achieved only 13.3% reduction, suggesting the recovery of 5-FU sensitivity in CAF-rich tumors. In conclusion, CAFs-PIT could overcome therapeutic resistance via CAF elimination. The combined use of novel targeted CAFs-PIT with conventional anticancer treatments can be expected to provide a more effective and sensible treatment strategy.

Cancer-associated fibroblast-secreted exosomal miR-423-5p promotes chemotherapy resistance in prostate cancer by targeting GREM2 through the TGF-β signaling pathway

Therapeutic failure in prostate cancer (PC) is believed to result from its unusually invasive and metastatic nature. Cancer-associated fibroblasts (CAFs) are essential in the tumor microenvironment. We intended to study the role of CAF-derived exosomes in the context of PC and the potential regulatory mechanism associated with miR-423-5p and GREM2. CAF-derived exosomes decreased the chemosensitivity of parental PC cells and enhanced the drug resistance of drug-resistant cells. PC-associated fibroblast-derived exosomes carrying miR-423-5p increased the resistance of PC to taxane by inhibiting GREM2 through the TGF-β pathway. Inhibition of the TGF-β pathway partially reversed the increased drug resistance in PC cells induced by CAF-derived exosomes. Inhibition of miR-423-5p enhanced the drug sensitivity of PC cells in vivo. We showed that CAF-secreted exosomal miR-423-5p promoted chemotherapy resistance in PC by targeting GREM2 through the TGF-β pathway. This study may allow the development of novel approaches for PC.

Effects of pirfenidone targeting the tumor microenvironment and tumor-stroma interaction as a novel treatment for non-small cell lung cancer

Targeting cancer-associated fibroblasts (CAFs), as well as the crosstalk between stroma and cancer cells, could be of value in managing cancers. Pirfenidone (PFD) is an anti-fibrotic agent for idiopathic pulmonary fibrosis. This study aimed to investigate the possibility that PFD might exert an anti-tumor effect through inhibition of fibroblast activation and the tumor-stroma interaction in non-small cell lung cancer (NSCLC) cell lines in vitro and in vivo. PFD significantly inhibited myofibroblast differentiation and activation of both primary cultured normal human lung fibroblasts and CAFs. Cocultivation of NSCLC cells with conditioned media (CM) of fibroblasts changed the morphology or epithelial to mesenchymal transition (EMT) status, and PFD suppressed these changes. Cocultivation of CAFs with CM of NSCLC cells also induced activation of CAFs, and these changes were suppressed by PFD. On in vivo examination, CAFs promoted tumor progression, and PFD suppressed tumor progression with an inhibitory effect on tumor-stroma crosstalk. PFD might inhibit not only fibroblast activity, but also the crosstalk between cancer cells and fibroblasts. PFD may have great potential as a novel treatment for NSCLC from multiple perspectives.

IL-6 promotes metastasis of non-small-cell lung cancer by up-regulating TIM-4 via NF-κB

OBJECTIVES

Interleukin-6 (IL-6) is critical for the development of non-small-cell lung cancer (NSCLC). Recently, we identified T-cell immunoglobulin domain and mucin domain 4 (TIM-4) as a new pro-growth player in NSCLC progression. However, the role of TIM-4 in IL-6-promoted NSCLC migration, invasion and epithelial-to-mesenchymal transition (EMT) remains unclear.

MATERIALS AND METHODS

Expressions of TIM-4 and IL-6 were both evaluated by immunohistochemical staining in NSCLC tissues. Real-time quantitative PCR (qPCR), Western blot, flow cytometry and RT-PCR were performed to detect TIM-4 expression in NSCLC cells with IL-6 stimulation. The roles of TIM-4 in IL-6 promoting migration and invasion of NSCLC were detected by transwell assay. EMT-related markers were analysed by qPCR and Western blot in vitro, and metastasis was evaluated in BALB/c nude mice using lung cancer metastasis mouse model in vivo.

RESULTS

High IL-6 expression was identified as an independent predictive factor for TIM-4 expression in NSCLC tissues. NSCLC patients with TIM-4 and IL-6 double high expression showed the worst prognosis. IL-6 promoted TIM-4 expression in NSCLC cells depending on NF-κB signal pathway. Both TIM-4 and IL-6 promoted migration, invasion and EMT of NSCLC cells. Interestingly, TIM-4 knockdown reversed the role of IL-6 in NSCLC and IL-6 promoted metastasis of NSCLC by up-regulating TIM-4 via NF-κB.

CONCLUSIONS

TIM-4 involves in IL-6 promoted migration, invasion and EMT of NSCLC.

Rho GTPases and related signaling complexes in cell migration and invasion

Cell migration and invasion play an important role in the development of cancer. Cell migration is associated with several specific actin filament-based structures, including lamellipodia, filopodia, invadopodia and blebs, and with cell-cell adhesion, cell-extracellular matrix adhesion. Migration occurs via different modes, human epithelial cancer cells mainly migrate collectively, while in vivo imaging studies in laboratory animals have found that most cells migrate as single cells. Rho GTPases play an important role in the process of cell migration, and several Rho GTPase-related signaling complexes are also involved. However, the exact mechanism by which these signaling complexes act remains unclear. This paper reviews how Rho GTPases and related signaling complexes interact with other proteins, how their expression is regulated, how tumor microenvironment-related factors play a role in invasion and metastasis, and the mechanism of these complex signaling networks in cell migration and invasion.

Extracellular Hsp70 Reduces the Pro-Tumor Capacity of Monocytes/Macrophages Co-Cultivated with Cancer Cells

Cancer cells are known to contain high levels of the heat shock protein 70 kDa (Hsp70), which mediates increased cell proliferation, escape from programmed cell death, enhanced invasion, and metastasis. A part of Hsp70 molecules may release from cancer cells and affect the behavior of adjacent stromal cells. To explore the effects of Hsp70 on the status of monocytes/macrophages in the tumor locale, we incubated human carcinoma cells of three distinct lines with normal and reduced content of Hsp70 with THP1 monocytes. Using two methods, we showed that the cells with knock-down of Hsp70 released a lower amount of protein in the extracellular medium. Three cycles of the co-cultivation of cancer and monocytic cells led to the secretion of several cytokines typical of the tumor microenvironment (TME) and to pro-cancer activation of the monocytes/macrophages as established by elevation of F4/80 and arginase-1 markers. Unexpectedly, the efficacy of epithelial–mesenchymal transition and resistance of carcinoma cells to anticancer drugs after incubation with monocytic cells were more pronounced in cells with lower Hsp70, e.g., releasing less Hsp70 into the extracellular milieu. These data suggest that Hsp70 released from tumor cells into the TME is able, together with the development of an anti-cancer immune response, to limit the conversion of a considerable part of monocytic cells to the pro-tumor phenotype.

ALI multilayered co-cultures mimic biochemical mechanisms of the cancer cell-fibroblast cross-talk involved in NSCLC MultiDrug Resistance

Background

Lung cancer is the leading cause of cancer-related deaths worldwide. This study focuses on its most common form, Non-Small-Cell Lung Cancer (NSCLC). No cure exists for advanced NSCLC, and patient prognosis is extremely poor. Efforts are currently being made to develop effective inhaled NSCLC therapies. However, at present, reliable preclinical models to support the development of inhaled anti-cancer drugs do not exist. This is due to the oversimplified nature of currently available in vitro models, and the significant interspecies differences between animals and humans.

Methods

We have recently established 3D Multilayered Cell Cultures (MCCs) of human NSCLC (A549) cells grown at the Air-Liquid Interface (ALI) as the first in vitro tool for screening the efficacy of inhaled anti-cancer drugs. Here, we present an improved in vitro model formed by growing A549 cells and human fibroblasts (MRC-5 cell line) as an ALI multilayered co-culture. The model was characterized over 14-day growth and tested for its response to four benchmarking chemotherapeutics.

Results

ALI multilayered co-cultures showed an increased resistance to the four drugs tested as compared to ALI multilayered mono-cultures. The signalling pathways involved in the culture MultiDrug Resistance (MDR) were influenced by the cancer cell-fibroblast cross-talk, which was mediated through TGF-β1 release and subsequent activation of the PI3K/AKT/mTOR pathway. As per in vivo conditions, when inhibiting mTOR phosphorylation, MDR was triggered by activation of the MEK/ERK pathway activation and up-regulation in cIAP-1/2 expression.

Conclusions

Our study opens new research avenues for the development of alternatives to animal-based inhalation studies, impacting the development of anti-NSCLC drugs.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-6038-x) contains supplementary material, which is available to authorized users.

Bone Metastasis Phenotype and Growth Undergo Regulation by Micro-Environment Stimuli: Efficacy of Early Therapy with HGF or TGFβ1-Type I Receptor Blockade

Hepatocyte growth factor (HGF) and transforming growth factor β1 (TGFβ1) are biological stimuli of the micro-environment which affect bone metastasis phenotype through transcription factors, but their influence on the growth is scarcely known. In a xenograft model prepared with 1833 bone metastatic cells, derived from breast carcinoma cells, we evaluated mice survival and Twist and Snail expression and localization after competitive inhibition of HGF with NK4, or after blockade of TGFβ1-type I receptor (RI) with SB431542: in the latter condition HGF was also measured. To explain the in vivo data, in 1833 cells treated with SB431542 plus TGFβ1 we measured HGF formation and the transduction pathway involved. Altogether, HGF seemed relevant for bone-metastatic growth, being hampered by NK4 treatment, which decreased Twist more than Snail in the metastasis bulk. TGFβ1-RI blockade enhanced HGF in metastasis and adjacent bone marrow, while reducing prevalently Snail expression at the front and bulk of bone metastasis. The HGF accumulation in 1833 cells depended on an auxiliary signaling pathway, triggered by TGFβ1 under SB431542, which interfered in the transcription of HGF activator inhibitor type 1 (HAI-1) downstream of TGFβ-activated kinase 1 (TAK1): HGF stimulated Twist transactivation. In conclusion, the impairment of initial outgrowth with NK4 seemed therapeutically promising more than SB431542 chemotherapy; a functional correlation between Twist and Snail in bone metastasis seemed to be influenced by the biological stimuli of the micro-environment, and the targeting of these phenotype biomarkers might inhibit metastasis plasticity and colonization, even if it would be necessary to consider the changes of HGF levels in bone metastases undergoing TGFβ1-RI blockade.

Role of tumor-associated neutrophils in regulation of tumor growth in lung cancer development: A mathematical model

Neutrophils display rapid and potent innate immune responses in various diseases. Tumor-associated neutrophils (TANs) however either induce or overcome immunosuppressive functions of the tumor microenvironment through complex tumor-stroma crosstalk. We developed a mathematical model to address the question of how phenotypic alterations between tumor suppressive N1 TANS, and tumor promoting N2 TANs affect nonlinear tumor growth in a complex tumor microenvironment. The model provides a visual display of the complex behavior of populations of TANs and tumors in response to various TGF-β and IFN-β stimuli. In addition, the effect of anti-tumor drug administration is incorporated in the model in an effort to achieve optimal anti-tumor efficacy. The simulation results from the mathematical model were in good agreement with experimental data. We found that the N2-to-N1 ratio (N21R) index is positively correlated with aggressive tumor growth, suggesting that this may be a good prognostic factor. We also found that the antitumor efficacy increases when the relative ratio (Dap) of delayed apoptotic cell death of N1 and N2 TANs is either very small or relatively large, providing a basis for therapeutically targeting prometastatic N2 TANs.

Glutamine Addiction and Therapeutic Strategies in Lung Cancer

Lung cancer cells are well-documented to rewire their metabolism and energy production networks to support rapid survival and proliferation. This metabolic reorganization has been recognized as a hallmark of cancer. The increased uptake of glucose and the increased activity of the glycolytic pathway have been extensively described. However, over the past years, increasing evidence has shown that lung cancer cells also require glutamine to fulfill their metabolic needs. As a nitrogen source, glutamine contributes directly (or indirectly upon conversion to glutamate) to many anabolic processes in cancer, such as the biosynthesis of amino acids, nucleobases, and hexosamines. It plays also an important role in the redox homeostasis, and last but not least, upon conversion to α-ketoglutarate, glutamine is an energy and anaplerotic carbon source that replenishes tricarboxylic acid cycle intermediates. The latter is generally indicated as glutaminolysis. In this review, we explore the role of glutamine metabolism in lung cancer. Because lung cancer is the leading cause of cancer death with limited curative treatment options, we focus on the potential therapeutic approaches targeting the glutamine metabolism in cancer.

Tumor-suppressive effects of microRNA-181d-5p on non-small-cell lung cancer through the CDKN3-mediated Akt signaling pathway in vivo and in vitro

The involvement of several microRNAs (miRs) in the initiation and development of tumors through the suppression of the target gene expression has been highlighted. The aberrant expression of miR-181d-5p and cyclin-dependent kinase inhibitor 3 (CDKN3) in non-small-cell lung cancer (NSCLC) was then screened by microarray analysis. In the present study, we performed a series of in vivo and in vitro experiments for the purpose of investigating their roles in NSCLC and the underlying mechanism. There was a high expression of CDKN3, whereas miR-181d-5p was downregulated in NSCLC. Quantitative RT-PCR, Western blot analysis, and dual-luciferase reporter gene assay further identified that CDKN3 could be negatively regulated by miR-181d-5p. Moreover, the upregulation of miR-181d-5p or silencing of CDKN3 could inactivate the Akt signaling pathway. A549 with the lowest miR-181d-5p and H1975 with the highest CDKN3 among the five NSCLC cell lines (H1299, A549, H1975, NCI-H157, and GLC-82) were adopted for in vitro experiments, in which expression of miR-181d-5p and CDKN3 was altered by transfection of miR-181d-5p mimic/inhibitor or siRNA-targeting CDKN3. Afterwards, cell proliferation, apoptosis, invasion, migration, and angiogenesis, as well as epithelial-mesenchymal transition (EMT), were evaluated, and tumorigenicity was assessed. In addition, an elevation in miR-181d-5p or depletion in CDKN3 led to significant reductions in proliferation, invasion, migration, angiogenesis, EMT, and tumorigenicity of NSCLC cells, coupling with increased cell apoptosis. In conclusion, this study highlights the tumor-suppressive effects of miR-181d-5p on NSCLC via Akt signaling pathway inactivation by suppressing CDKN3, thus providing a promising therapeutic strategy for the treatment of NSCLC.

The lung microenvironment: an important regulator of tumour growth and metastasis

Lung cancer is a major global health problem, as it is the leading cause of cancer-related deaths worldwide. Major advances in the identification of key mutational alterations have led to the development of molecularly targeted therapies, whose efficacy has been limited by emergence of resistance mechanisms. US Food and Drug Administration (FDA)-approved therapies targeting angiogenesis and more recently immune checkpoints have reinvigorated enthusiasm in elucidating the prognostic and pathophysiological roles of the tumour microenvironment in lung cancer. In this Review, we highlight recent advances and emerging concepts for how the tumour-reprogrammed lung microenvironment promotes both primary lung tumours and lung metastasis from extrapulmonary neoplasms by contributing to inflammation, angiogenesis, immune modulation and response to therapies. We also discuss the potential of understanding tumour microenvironmental processes to identify biomarkers of clinical utility and to develop novel targeted therapies against lung cancer.

Cancer-associated fibroblasts contribute to oral cancer cells proliferation and metastasis via exosome-mediated paracrine miR-34a-5p

Background

Cancer-associated fibroblasts (CAFs) play an important role in regulating tumor progression by transferring exosomes to neighboring cells. Our aim was to clarify the role of microRNA encapsulated in the exosomes derived from CAFs in oral squamous cell carcinoma (OSCC).

Methods

We examined the microRNA expression profiles of exosomes derived from CAFs and donor-matched normal fibroblasts (NFs) from patients with OSCC. We used confocal microscopy to examine the transportation of exosomal miR-34a-5p between CAFs and OSCC cells. Next, luciferase reporter and its mutant plasmids were used to confirm direct target gene of miR-34a-5p. Phenotypic assays and in vivo tumor growth experiments were used to investigate the functional significance of exosomal miR-34a-5p.

Findings

We found that the expression of miR-34a-5p in CAF-derived exosomes was significantly reduced, and fibroblasts could transfer exosomal miR-34a-5p to OSCC cells. In xenograft experiments, miR-34a-5p overexpression in CAFs could inhibit the tumorigenesis of OSCC cells. We further revealed that miR-34a-5p binds to its direct downstream target AXL to suppress OSCC cell proliferation and metastasis. Stable ectopic expression of AXL in OSCC cells overexpressing miR-34a-5p restored proliferation and motility abolished by the miRNA. The miR-34a-5p/AXL axis promoted OSCC progression via the AKT/GSK-3β/β-catenin signaling pathway, which could induce the epithelial-mesenchymal transition (EMT) to promote cancer cells metastasis. The miR-34a-5p/AXL axis enhanced nuclear translocation of β-catenin and then induced transcriptional upregulation of SNAIL, which in turn activated both MMP-2 and MMP-9.

Interpretation

The miR-34a-5p/AXL axis confers aggressiveness in oral cancer cells through the AKT/GSK-3β/β-catenin/Snail signaling cascade and might represent a therapeutic target for OSCC.

Fund

National Natural Science Foundation of China.

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CAFs transfer miR-34a-5p-devoid exosomes to OSCC cells.

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Exosomal miR-34a-5p mediates the proliferation and motility of OSCC cells through regulating AXL.

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MiR-34a-5p/AXL axis confers aggressiveness in OSCC through AKT/GSK-3β/β-catenin/Snail signaling cascade.

Sorafenib inhibits macrophage-mediated epithelial-mesenchymal transition in hepatocellular carcinoma

Tumor-associated macrophages, crucial components of the microenvironment in hepatocellular carcinoma, hamper anti-cancer immune responses. The aim of the present study was to investigate the effect of sorafenib on the formation of the tumor microenvironment, especially the relationship between polarized macrophages and hepatocytes. Macrophage infiltration was reduced in patients with hepatocellular carcinoma who were treated with sorafenib. In vitro, sorafenib abolished polarized macrophage-induced epithelial mesenchymal transition (EMT) and migration of hepatocellular carcinoma cells but not normal hepatocytes. Moreover, sorafenib attenuated HGF secretion in polarized macrophages, and decreased plasma HGF in patients with hepatocellular carcinoma. Additionally, sorafenib abolished the polarized macrophage-induced activation of the HGF receptor Met in hepatocellular carcinoma cells. Our findings suggest that sorafenib inhibits polarized macrophage-induced EMT in hepatocellular carcinoma cells via the HGF-Met signaling pathway. These results contribute to our understanding of the immunological mechanisms that underlie the protective effects of sorafenib in hepatocellular carcinoma therapy.

Gankyrin promotes epithelial-mesenchymal transition and metastasis in NSCLC through forming a closed circle with IL-6/ STAT3 and TGF-β/SMAD3 signaling pathway

Our previous research showed that Gankyrin was overexpressed in NSCLC and significantly associated with clinicopathologic features and poor prognosis. In this study, we will explore potential effect of Gankyrin on EMT and metastasis in NSCLC. The ectopic higher expression of Gankyrin markedly increased the migration and invasion in NSCLC cells. In contrast, silencing Gankyrin inhibit this aggressive behavior in NSCLC cells. Further study demonstrated that overexpression of Gankyrin could decrease E-cadherin expression and increase expression of Vimentin and Twist1 at mRNA and protein levels. These data indicated that Gankyrin could facilitate occurrence and development of EMT. Also IHC analysis showed that Gankyrin expression was negatively correlated with E-cadherin expression, while positively correlated with Vimentin and Twist1 expression in NSCLC tissues. The mechanism study finally suggested that the Gankyrin-driven EMT was partially due to IL-6/p-STAT3 and TGF-β/p-SMAD3 pathways activation. Taken together, our data provided a novel mechanism of Gankyrin promoting EMT and metastasis in NSCLC through forming a closed circle with IL-6/p-STAT3 and TGF-β/p-SMAD3 signaling pathway.

Apatinib inhibits macrophage-mediated epithelial–mesenchymal transition in lung cancer

Chemotherapy is one of the main treatment approaches for lung cancer.

Epithelial-mesenchymal transition and inflammation at the site of the primary tumor

Tumor growth and progression are the products of complex signaling networks between different cell types within the tumor and its surrounding stroma. In particular, established tumors are known to stimulate an inflammatory reaction via the secretion of cytokines, chemokines, and growth factors that favor the recruitment of a range of infiltrating immune cell populations into the tumor microenvironment. While potentially able to exert tumor control, this inflammatory reaction is typically seized upon by the tumor to promote its own growth and progression towards metastasis. This review focuses on recent advances in understanding how an established tumor can initiate an inflammatory response via the release of pro-inflammatory mediators, such as IL-6 and IL-8, and their roles in cancer metastasis. In particular, the role of the epithelial-mesenchymal transition (EMT), a phenotypic switch observed in carcinomas that promotes progression towards metastasis, is discussed here in relation to cancer inflammation.

Gas6 derived from cancer-associated fibroblasts promotes migration of Axl-expressing lung cancer cells during chemotherapy

Alterations to the tumor stromal microenvironment induced by chemotherapy could influence the behavior of cancer cells. In the tumor stromal microenvironment, cancer-associated fibroblasts (CAFs) play an important role. Because the receptor tyrosine kinase Axl and its ligand Gas6 could be involved in promoting non-small cell lung cancer (NSCLC), we investigated the role of Gas6 secreted by CAFs during chemotherapy in NSCLC. In a murine model, we found that Gas6 expression by CAFs was upregulated following cisplatin treatment. Gas6 expression might be influenced by intratumoral hypoperfusion during chemotherapy, and it increased after serum starvation in a human lung CAF line, LCAF^hTERT. Gas6 is associated with LCAF^hTERT cell growth. Recombinant Gas6 promoted H1299 migration, and conditioned medium (CM) from LCAF^hTERT cells activated Axl in H1299 cells and promoted migration. Silencing Gas6 in LCAF^hTERT reduced the Axl activation and H1299 cell migration induced by CM from LCAF^hTERT. In clinical samples, stromal Gas6 expression increased after chemotherapy. Five-year disease-free survival rates for patients with tumor Axl- and stromal Gas6-positive tumors (n = 37) was significantly worse than for the double negative group (n = 12) (21.9% vs 51.3%, p = 0.04). Based on these findings, it is presumed that Gas6 derived from CAFs promotes migration of Axl-expressing lung cancer cells during chemotherapy and is involved in poor clinical outcome.

Chemotherapy enhances programmed cell death 1/ligand 1 expression via TGF-β induced epithelial mesenchymal transition in non-small cell lung cancer

In cancer immunology, the programmed cell death 1-programmed cell death 1/ligand 1 (PD-1/PD-L1) pathway plays a major role. Anti-PD-1 and anti-PD-L1 antibodies provide reliable immunotherapy when given as treatment for various types of malignancy including lung cancer. PD-L1 expression in cancer cells has been reported to be a predictive factor for the therapeutic effects of immunotherapy. However, the mechanism of PD-L1 expression remains unclear. Another key process in cancer progression is epithelial-mesenchymal transition (EMT). In the present study, we investigated the mechanism of PD-L1 expression as well as changes in its expression during the EMT process in non-small cell lung cancer (NSCLC). In this study, A549 cells underwent EMT by treatment with TGF-β or chemotherapeutic agents and then PD-L1 expression was evaluated. The alterations of PD-L1 expression was also examined during the reverse EMT process; mesenchymal-epithelial transition (MET). The relationship between for PD-L1 expression and EMT status in clinical specimens with NSCLC after induction chemotherapy were analyzed by immunohistochemical staining. We found that PD-L1 expression was upregulated following TGF-β induction; in contrast, it was downregulated by TGF-β receptor-kinase inhibitors and the MET process. Furthermore, chemo-treatment increased TGF-β expression and enhances PD-L1 expression via autocrine TGF-β induced EMT. Analysis of clinical samples revealed a significant relationship between PD-L1 expression and EMT status (P<0.05). In conclusion, our results suggest that PD-L1 expression is regulated by TGF-β induced EMT and enhanced by chemo-treatment via the chemo-induced TGF-β signaling. The anti-PD-1/PD-L1 blockade may provide more effective anticancer activities in combination with chemotherapy in NSCLC.

The Role of Tumor Microenvironment in Chemoresistance: To Survive, Keep Your Enemies Closer

Chemoresistance is a leading cause of morbidity and mortality in cancer and it continues to be a challenge in cancer treatment. Chemoresistance is influenced by genetic and epigenetic alterations which affect drug uptake, metabolism and export of drugs at the cellular levels. While most research has focused on tumor cell autonomous mechanisms of chemoresistance, the tumor microenvironment has emerged as a key player in the development of chemoresistance and in malignant progression, thereby influencing the development of novel therapies in clinical oncology. It is not surprising that the study of the tumor microenvironment is now considered to be as important as the study of tumor cells. Recent advances in technological and analytical methods, especially ‘omics’ technologies, has made it possible to identify specific targets in tumor cells and within the tumor microenvironment to eradicate cancer. Tumors need constant support from previously ‘unsupportive’ microenvironments. Novel therapeutic strategies that inhibit such microenvironmental support to tumor cells would reduce chemoresistance and tumor relapse. Such strategies can target stromal cells, proteins released by stromal cells and non-cellular components such as the extracellular matrix (ECM) within the tumor microenvironment. Novel in vitro tumor biology models that recapitulate the in vivo tumor microenvironment such as multicellular tumor spheroids, biomimetic scaffolds and tumor organoids are being developed and are increasing our understanding of cancer cell-microenvironment interactions. This review offers an analysis of recent developments on the role of the tumor microenvironment in the development of chemoresistance and the strategies to overcome microenvironment-mediated chemoresistance. We propose a systematic analysis of the relationship between tumor cells and their respective tumor microenvironments and our data show that, to survive, cancer cells interact closely with tumor microenvironment components such as mesenchymal stem cells and the extracellular matrix.

Matrine increases the inhibitory effects of afatinib on H1975 cells via the IL‑6/JAK1/STAT3 signaling pathway

Resistance to epidermal growth factor receptor (EGFR) inhibitors is of primary concern in the treatment of non-small-cell lung cancer (NSCLC) with EGFR mutations. To investigate the effects of matrine on H1975 cells and to examine a novel, potential treatment option for NSCLC, the present study measured cell viability, apoptotic rate, interleukin 6 (IL-6) expression and activation of the janus kinase (JAK) 1/signal transducer and activator of transcription (STAT)3 signaling pathway in cells treated with or without matrine, in the presence or absence of afatinib. The results demonstrated that matrine treatment inhibited cell growth, decreased B-cell lymphoma 2 (Bcl-2) expression and induced apoptosis. Matrine treatment additionally decreased the mRNA and protein levels of IL-6 and inhibited activation of the JAK1/STAT3 signaling pathway in H1975 cells in a dose-dependent manner. H1975 cells treated with IL-6 small interfering RNA exhibited a decrease in Bcl-2 expression levels and cell viability. Treatment with a combination of matrine and afatinib demonstrated increased inhibitory effects on the growth rate of H1975 cells. The findings of the present study suggested that matrine treatment decreases IL-6 expression, inhibits activation of the JAK1/STAT3 signaling pathway, reduces the expression levels of Bcl-2 and inhibits cell growth. Furthermore, matrine treatment was demonstrated to increase the inhibitory effects of afatinib on H1975 cells with the T790M EGFR mutation.

Podocalyxin influences malignant potential by controlling epithelial-mesenchymal transition in lung adenocarcinoma

Epithelial-mesenchymal transition (EMT) plays an important role in the progression of lung carcinoma. Podocalyxin (PODXL), which belongs to the CD34 family and regulates cell morphology, has been linked to EMT in lung cancer, and PODXL overexpression is associated with poor prognosis in several different classes of cancers. The aim of this study was to clarify the role of PODXL overexpression in EMT in lung cancer, and to determine the prognostic value of PODXL overexpression in tumors from lung cancer patients. The morphology, EMT marker expression, and migration and invasion abilities of engineered A549 PODXL-knockdown (KD) or PODXL-overexpression (OE) lung adenocarcinoma cells were examined. PODXL expression levels were assessed by immunohistochemistry in 114 human clinical lung adenocarcinoma specimens and correlated with clinical outcomes. PODXL-KD cells were epithelial in shape, whereas PODXL-OE cells displayed mesenchymal morphology. Epithelial markers were upregulated in PODXL-KD cells and downregulated in PODXL-OE cells, whereas mesenchymal markers were downregulated in the former and upregulated in the latter. A highly selective inhibitor of phosphatidylinositol 3-kinase-Akt signaling attenuated EMT of PODXL-OE cells, while a transforming growth factor inhibitor did not, suggesting that PODXL induces EMT of lung adenocarcinoma cells via the phosphatidylinositol 3-kinase pathway. In lung adenocarcinoma clinical specimens, PODXL expression was detected in minimally invasive and invasive adenocarcinoma, but not in non-invasive adenocarcinoma. Disease free survival and cancer-specific survival were significantly worse for patients whose tumors overexpressed PODXL. PODXL overexpression induces EMT in lung adenocarcinoma and contributes to tumor progression.

Concomitant Interstitial Lung Disease Is a Risk Factor for Pleural Invasion in Lung Cancer

BACKGROUND

Lung carcinoma is often associated with interstitial lung disease (ILD), and the prognosis of lung cancer accompanied by ILD is unfavorable. In this study, cases of patients with primary lung cancer with or without ILD were reviewed to analyze surgical outcome, with special interest in the conformity of clinical and pathologic stages, pathologic findings of pleural invasion, malignant pleurisy first detected at the time of thoracotomy, and survival.

METHODS

Retrospective chart review was performed for 1,264 primary lung cancer patients who underwent surgery from 2004 to 2015. Concomitant ILD was diagnosed by pathological examination or preoperative chest computed tomography findings.

RESULTS

ILD was found in 104 patients (8.2%) with primary lung cancer. Conformity of clinical and pathological stages in the ILD-positive patients was poor, with a lower kappa value than that for the 1,160 ILD-negative patients (0.34 versus 0.51). The ILD group had significantly higher incidences of pleural invasion and unexpected malignant pleurisy than did the non-ILD group (for pleural invasion, 49.0% versus 24.5%, p < 0.0001; for malignant pleurisy, 7.69% versus 1.47%, p < 0.0001). The 5-year overall survival rates of the ILD group showed significantly lower than those of the non-ILD group (45.2% versus 70.1%; p = 0.0014) after propensity score matching.

CONCLUSIONS

In lung cancer, the concomitant existence of ILD is a risk factor for pleural invasion. Concomitant ILD might cause underestimation of clinical staging, increase the chance of unexpected malignant pleurisy during surgery, and shorten survival time.

Epithelial-mesenchymal transition, inflammatory bowel disease and colitis associated colorectal cancer

Chronic inflammation can induce the formation of a wide variety of tumors. Inflammatory bowel disease is one of the major risk factors for colorectal cancer. Epithelial-mesenchymal transition (EMT) can promote the invasion and metastasis of a variety of cancer cells, including colorectal cancer cells. Different kinds of inflammatory cytokines produced in inflammatory bowel disease could mediate the activation of EMT through a series of pathways, and thus promote the occurrence and development of colitis associated colorectal cancer. This article explores the relationship among EMT, inflammatory bowel disease and colitis associated colorectal cancer, with an aim to provide new ideas and methods for the clinical treatment of colitis associated colorectal cancer.

Microwave-irradiation-assisted hybrid chemical approach for titanium dioxide nanoparticle synthesis: microbial and cytotoxicological evaluation

Titanium dioxide nanoparticles (TNPs) are widely used in the pharmaceutical and cosmetics industries. It is used for protection against UV exposure due to its light-scattering properties and high refractive index. Though TNPs are increasingly used, the synthesis of TNPs is tedious and time consuming; therefore, in the present study, microwave-assisted hybrid chemical approach was used for TNP synthesis. In the present study, we demonstrated that TNPs can be synthesized only in 2.5 h; however, the commonly used chemical approach using muffle furnace takes 5 h. The activity of TNP depends on the synthetic protocol; therefore, the present study also determined the effect of microwave-assisted hybrid chemical approach synthetic protocol on microbial and cytotoxicity. The results showed that TNP has the best antibacterial activity in decreasing order from Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. The IC50 values of TNP for HCT116 and A549 were found to be 6.43 and 6.04 ppm, respectively. Cell death was also confirmed from trypan blue exclusion assay and membrane integrity loss was observed. Therefore, the study determines that the microwave-assisted hybrid chemical approach is time-saving; hence, this technique can be upgraded from lab scale to industrial scale via pilot plant scale. Moreover, it is necessary to find the mechanism of action at the molecular level to establish the reason for greater bacterial and cytotoxicological toxicity. Graphical abstract A graphical representation of TNP synthesis.

Cancer development, chemoresistance, epithelial to mesenchymal transition and stem cells: A snapshot of IL-6 mediated involvement

Interleukin-6 (IL-6) is a cytokine present in tumor microenvironment. Elevated level of IL-6 is associated with cancer cell proliferation, angiogenesis and metastasis through fueling STAT3, MAPK and Akt signaling. It promotes epithelial to mesenchymal transition (EMT) through altered expression of N-cadherin, vimentin, snail, twist and E-cadherin leading to cancer metastasis. IL-6 boosts mammosphere formation, self-renewal of stem cells, stemness properties of cancer cells and recruitment of mesenchymal stem cells. IL-6 is also a contributing factor for multidrug resistance in cancer due to gp130/MAPK/STAT3 mediated activation of transcription factors C/EBPβ/δ, overexpression of p-glycoprotein, EMT transition and expansion of stem cells. The in-depth investigation of IL-6 mediated cellular effects and its signaling pathway can provide the new window for future research and clinical development of IL-6 targeted therapy in cancer. Thus, an overview is delivered in this review deciphering the emerging aspect of the predominant influence of IL-6 in malignant transformation, EMT, cancer-associated stem cells and chemoresistance.

Whom to blame for metastasis, the epithelial-mesenchymal transition or the tumor microenvironment?

Changes in the tumor microenvironment (TME) can trigger the activation of otherwise non-malignant cells to become highly aggressive and motile. This is evident during initial tumor growth when the poor vascularization in tumors generates hypoxic regions that trigger the latent embryonic program, epithelial-to-mesenchymal transition (EMT), in epithelial carcinoma cells (e-cars) leading to highly motile mesenchymal-like carcinoma cells (m-cars), which also acquire cancer stem cell properties. After that, specific bidirectional interactions take place between m-cars and the cellular components of TME at different stages of metastasis. These interactions include several vicious positive feedback loops in which m-cars trigger a phenotypic switch, causing normal stromal cells to become pro-tumorigenic, which then further promote the survival, motility, and proliferation of m-cars. Accordingly, there is not a single culprit accounting for metastasis. Instead both m-cars and the TME dynamically interact, evolve and promote metastasis. In this review, we discuss the current status of the known interactions between m-cars and the TME during different stages of metastasis and how these interactions promote the metastatic activity of highly malignant m-cars by promoting their invasive mesenchymal phenotype and CSC properties.

The tumor microenvironment: An irreplaceable element of tumor budding and epithelial-mesenchymal transition-mediated cancer metastasis

Tumor budding occurs at the invasive front of cancer; the tumor cells involved have metastatic and stemness features, indicating a poor prognosis. Tumor budding is partly responsible for cancer metastasis, and its initiation is based on the epithelial-mesenchymal transition (EMT) process. The EMT process involves the conversion of epithelial cells into migratory and invasive cells, and is a profound event in tumorigenesis. The EMT, associated with the formation of cancer stem cells (CSCs) and resistance to therapy, results from a combination of gene mutation, epigenetic regulation, and microenvironmental control. Tumor budding can be taken to represent the EMT in vivo. The EMT process is under the influence of the tumor microenvironment as well as tumor cells themselves. Here, we demonstrate that the tumor microenvironment dominates EMT development and impacts cancer metastasis, as well as promotes CSC formation and mediates drug resistance. In this review, we mainly discuss components of the microenvironment, such as the extracellular matrix (ECM), inflammatory cytokines, metabolic products, and hypoxia, that are involved in and impact on the acquisition of tumor-cell motility and dissemination, the EMT, metastatic tumor-cell formation, tumor budding and CSCs, and cancer metastasis, including subsequent chemo-resistance. From our point of view, the tumor microenvironment now constitutes a promising target for cancer therapy.

The Microenvironment of Lung Cancer and Therapeutic Implications

The tumor microenvironment (TME) represents a milieu that enables tumor cells to acquire the hallmarks of cancer. The TME is heterogeneous in composition and consists of cellular components, growth factors, proteases, and extracellular matrix. Concerted interactions between genetically altered tumor cells and genetically stable intratumoral stromal cells result in an "activated/reprogramed" stroma that promotes carcinogenesis by contributing to inflammation, immune suppression, therapeutic resistance, and generating premetastatic niches that support the initiation and establishment of distant metastasis. The lungs present a unique milieu in which tumors progress in collusion with the TME, as evidenced by regions of aberrant angiogenesis, acidosis and hypoxia. Inflammation plays an important role in the pathogenesis of lung cancer, and pulmonary disorders in lung cancer patients such as chronic obstructive pulmonary disease (COPD) and emphysema, constitute comorbid conditions and are independent risk factors for lung cancer. The TME also contributes to immune suppression, induces epithelial-to-mesenchymal transition (EMT) and diminishes efficacy of chemotherapies. Thus, the TME has begun to emerge as the "Achilles heel" of the disease, and constitutes an attractive target for anti-cancer therapy. Drugs targeting the components of the TME are making their way into clinical trials. Here, we will focus on recent advances and emerging concepts regarding the intriguing role of the TME in lung cancer progression, and discuss future directions in the context of novel diagnostic and therapeutic opportunities.

Regulation of Gene Expression by Sodium Valproate in Epithelial-to-Mesenchymal Transition

PURPOSE

Epithelial-to-mesenchymal transition (EMT) is an important mechanism in cancer metastasis and pulmonary fibrosis. Previous studies demonstrated effect of histone H3 and H4 acetylation in cancer and pulmonary fibrosis, so we hypothesized that histone modification might play a crucial role in gene regulation during EMT. In this study, we investigated the mechanism behind EMT by analyzing comprehensive gene expression and the effect of sodium valproate (VPA), a class I histone deacetylase inhibitory drug, on histone modification.

METHODS

EMT was induced in human alveolar epithelial cells (A549) using 5 ng/mL of transforming growth factor (TGF)-β1. Various concentrations of VPA were then administered, and Western blotting was used to analyze histone acetylation or methylation. Comprehensive gene expression analysis was carried out by RNA sequencing, and chromatin immunoprecipitation was performed with an anti-acetyl histone H3 lysine 27 antibody.

RESULTS

TGF-β1 stimulation led to a decrease in histone acetylation, especially that of histone H3K27, and H3K27ac localization was decreased at particular gene loci. This decrease was recovered by VPA treatment, which also up-regulated the mRNA expression of genes down-regulated by TGF-β1, and correlated with the localization of H3K27ac. However, genes up-regulated by TGF-β1 stimulation were not suppressed by VPA, with the exception of COL1A1.

CONCLUSIONS

Histone acetylation was down-regulated by TGF-β1 stimulation in A549 cells. VPA partially inhibited EMT and the decrease of histone acetylation, which plays an important role in the progression of EMT.

Suitable parameter choice on quantitative morphology of A549 cell in epithelial-mesenchymal transition

Evaluation of morphological changes in cells is an integral part of study on epithelial to mesenchymal transition (EMT), however, only a few papers reported the changes in quantitative parameters and no article compared different parameters for demanding better parameters. In the study, the purpose was to investigate suitable parameters for quantitative evaluation of EMT morphological changes. A549 human lung adenocarcinoma cell line was selected for the study. Some cells were stimulated by transforming growth factor-β1 (TGF-β1) for EMT, and other cells were as control without TGF-β1 stimulation. Subsequently, cells were placed in phase contrast microscope and three arbitrary fields were captured and saved with a personal computer. Using the tools of Photoshop software, some cells in an image were selected, segmented out and exchanged into unique hue, and other part in the image was shifted into another unique hue. The cells were calculated with 29 morphological parameters by Image Pro Plus software. A parameter between cells with or without TGF-β1 stimulation was compared statistically and nine parameters were significantly different between them. Receiver operating characteristic curve (ROC curve) of a parameter was described with SPSS software and F-test was used to compare two areas under the curves (AUCs) in Excel. Among them, roundness and radius ratio were the most AUCs and were significant higher than the other parameters. The results provided a new method with quantitative assessment of cell morphology during EMT, and found out two parameters, roundness and radius ratio, as suitable for quantification.