Molecular pathways: linking tumor microenvironment to epithelial-mesenchymal transition in metastasis

The Molecular Interaction of Collagen with Cell Receptors for Biological Function

Collagen, an extracellular protein, covers the entire human body and has several important biological functions in normal physiology. Recently, collagen from non-human sources has attracted attention for therapeutic management and biomedical applications. In this regard, both land-based animals such as cow, pig, chicken, camel, and sheep, and marine-based resources such as fish, octopus, starfish, sea-cucumber, and jellyfish are widely used for collagen extraction. The extracted collagen is transformed into collagen peptides, hydrolysates, films, hydrogels, scaffolds, sponges and 3D matrix for food and biomedical applications. In addition, many strategic ideas are continuously emerging to develop innovative advanced collagen biomaterials. For this purpose, it is important to understand the fundamental perception of how collagen communicates with receptors of biological cells to trigger cell signaling pathways. Therefore, this review discloses the molecular interaction of collagen with cell receptor molecules to carry out cellular signaling in biological pathways. By understanding the actual mechanism, this review opens up several new concepts to carry out next level research in collagen biomaterials.

Somatic mutations in collagens are associated with a distinct tumor environment and overall survival in gastric cancer

BACKGROUND

Gastric cancer is a heterogeneous disease with poorly understood genetic and microenvironmental factors. Mutations in collagen genes are associated with genetic diseases that compromise tissue integrity, but their role in tumor progression has not been extensively reported. Aberrant collagen expression has been long associated with malignant tumor growth, invasion, chemoresistance, and patient outcomes. We hypothesized that somatic mutations in collagens could functionally alter the tumor extracellular matrix.

METHODS

We used publicly available datasets including The Tumor Cancer Genome Atlas (TCGA) to interrogate somatic mutations in collagens in stomach adenocarcinomas. To demonstrate that collagens were significantly mutated above background mutation rates, we used a moderated Kolmogorov-Smirnov test along with combination analysis with a bootstrap approach to define the background accounting for mutation rates. Association between mutations and clinicopathological features was evaluated by Fisher or chi-squared tests. Association with overall survival was assessed by Kaplan-Meier and the Cox-Proportional Hazards Model. Gene Set Enrichment Analysis was used to interrogate pathways. Immunohistochemistry and in situ hybridization tested expression of COL7A1 in stomach tumors.

RESULTS

In stomach adenocarcinomas, we identified individual collagen genes and sets of collagen genes harboring somatic mutations at a high frequency compared to background in both microsatellite stable, and microsatellite instable tumors in TCGA. Many of the missense mutations resemble the same types of loss of function mutations in collagenopathies that disrupt tissue formation and destabilize cells providing guidance to interpret the somatic mutations. We identified combinations of somatic mutations in collagens associated with overall survival, with a distinctive tumor microenvironment marked by lower matrisome expression and immune cell signatures. Truncation mutations were strongly associated with improved outcomes suggesting that loss of expression of secreted collagens impact tumor progression and treatment response. Germline collagenopathy variants guided interpretation of impactful somatic mutations on tumors.

CONCLUSIONS

These observations highlight that many collagens, expressed in non-physiologically relevant conditions in tumors, harbor impactful somatic mutations in tumors, suggesting new approaches for classification and therapy development in stomach cancer. In sum, these findings demonstrate how classification of tumors by collagen mutations identified strong links between specific genotypes and the tumor environment.

Organ on Chip Technology to Model Cancer Growth and Metastasis

Organ on chip (OOC) has emerged as a major technological breakthrough and distinct model system revolutionizing biomedical research and drug discovery by recapitulating the crucial structural and functional complexity of human organs in vitro. OOC are rapidly emerging as powerful tools for oncology research. Indeed, Cancer on chip (COC) can ideally reproduce certain key aspects of the tumor microenvironment (TME), such as biochemical gradients and niche factors, dynamic cell-cell and cell-matrix interactions, and complex tissue structures composed of tumor and stromal cells. Here, we review the state of the art in COC models with a focus on the microphysiological systems that host multicellular 3D tissue engineering models and can help elucidate the complex biology of TME and cancer growth and progression. Finally, some examples of microengineered tumor models integrated with multi-organ microdevices to study disease progression in different tissues will be presented.

Spontaneous formation and spatial self-organization of mechanically induced mesenchymal-like cells within geometrically confined cancer cell monolayers

There is spatiotemporal heterogeneity in cell phenotypes and mechanical properties in tumor tissues, which is associated with cancer invasion and metastasis. It is well-known that exogenous growth factors like transforming growth factor (TGF)-β, can induce epithelial-mesenchymal transition (EMT)-based phenotypic transformation and the formation of EMT patterning on geometrically confined monolayers with mechanics heterogeneity. In the absence of exogenous TGF-β stimulation, however, whether geometric confinement-caused mechanics heterogeneity of cancer cell monolayers alone can trigger the EMT-based phenotypic heterogeneity still remains mysterious. Here, we develop a micropattern-based cell monolayer model to investigate the regulation of mechanics heterogeneity on the cell phenotypic switch. We reveal that mechanics heterogeneity itself is enough to spontaneously induce the emergence of mesenchymal-like phenotype and asymmetrical activation of TGF-β-SMAD signaling. Spatiotemporal dynamics of patterned cell monolayers with mesenchymal-like phenotypes is essentially regulated by tissue-scale cell behaviors like proliferation, migration as well as heterogeneous cytoskeletal contraction. The inhibition of cell contraction abrogates the asymmetrical TGF-β-SMAD signaling activation level and the emergence of mesenchymal-like phenotype. Our work not only sheds light on the key regulation of mechanics heterogeneity caused by spatially geometric confinement on regional mesenchymal-like phenotype of cancer cell monolayers, but highlights the key role of biophysical/mechanical cues in triggering phenotypic switch.

AEBP1 Is One of the Epithelial-Mesenchymal Transition Regulatory Genes in Colon Adenocarcinoma

Epithelial-mesenchymal transition (EMT) is involved in various tumor processes, including tumorigenesis, tumor cell migration and metastasis, tumor stemness, and therapeutic resistance. Therefore, it is important to identify the genes most associated with EMT and develop them as therapeutic targets. In this work, we first analyzed EMT hallmark gene expression profiles among 10,535 pan-cancer samples from The Cancer Genome Atlas (TCGA) and divided them into EMT high and EMT low groups according to the metagene scores. Then, we identified 12 genes that were most associated with high EMT metagene score (R > 0.9) in 329 colon adenocarcinoma (COAD) patients. Among them, only 4 genes (AEBP1, KCNE4, GFPT2, and FAM26E) had statistically significant differences in prognosis (P < 0.05). Next, we selected AEBP1 as a candidate and showed that AEBP1 mRNA levels and EMT biomarkers strongly coexpressed in 329 COAD samples. In addition, AEBP1 was highly expressed and associated with poor clinical outcomes and prognosis in COAD patients. Finally, to explore whether AEBP1-mediated EMT was related to the tumor microenvironment (TME), we examined AEBP1 expression levels at the single-cell levels. Our results showed that AEBP1 levels were extremely high in tumor-associated fibroblasts, which may induce EMT. AEBP1 expression was also positively correlated with the expression of fibroblast biomarkers and also with EMT metascores, suggesting that AEBP1-mediated EMT may be associated with the stimulation of fibroblast activation. Therefore, AEBP1 may be a promising target for EMT inhibition, which reduces cancer metastasis and drug resistance in COAD patients.

Positive Reciprocal Feedback of lncRNA ZEB1-AS1 and HIF-1α Contributes to Hypoxia-Promoted Tumorigenesis and Metastasis of Pancreatic Cancer

Background

Many studies have reported the roles of the extracellular hypoxia microenvironment in the tumorigenesis and metastasis of multiple cancers. However, long noncoding RNAs (lncRNAs) that induce cancer oncogenicity and metastasis of pancreatic cancer (PC) under hypoxia conditions remain unclear.

Methods

In PC cells, the expression levels of lncRNAs in different conditions (normoxia or hypoxia) were compared through RNA sequencing (RNA-seq). The effects of the zinc finger E-box-binding homeobox 1 (ZEB1-AS1) antisense lncRNA on PC cells cultured in normoxia/hypoxia medium were measured through gain and loss-of-function experiments. Fluorescence in situ hybridization and luciferase reporter assays in addition to in vivo studies were utilized to explore the adaptive mechanisms of ZEB1-AS1 in the hypoxia-promoted proliferation, migration, and invasion ability of PC cells. Moreover, the level of ZEB1-AS1 and its associated targets or pathways were investigated in both PC and pancreatic normal tissues.

Results

RNA-seq revealed that ZEB1-AS1 was significantly upregulated in PC cells under hypoxia conditions. The ZEB1-AS1 expression level was closely associated with poor prognosis of PC patients. Knockdown of ZEB1-AS1 suppressed the proliferation, migration, and invasion of PC cells in vitro as well as PC xenograft tumor growth in vivo. In PC cells, RNAi-mediated reduction of ZEB1-AS1 inhibited zinc finger E-box-binding homeobox 1 (ZEB1), while ZEB1-AS1 overexpression rescued ZEB1 expression, indicating that ZEB1-AS1 promotes ZEB1 expression. Moreover, hypoxia-inducible factor-1α (HIF-1α)induced the expression of ZEB1-AS1 by binding to the ZEB1-AS1 promoter, which contains a putative hypoxia response element (HRE). Mechanistically, ZEB1-AS1 scaffolded the interaction among HIF-1α, ZEB1, and histone deacetylase 1 (HDAC1), leading to deacetylation-mediated stabilization of HIF-1α. We further revealed that ZEB1 induced the deacetylase capacity of HDAC1 to suppress the acetylation or degradation of HIF-1α, improving HIF-1α assembly. Thus, hypoxia-induced ZEB1-AS1 facilitated ZEB1 transcription and the stability of HIF-1α, which promoted the metastasis of PC cells. Clinically, dysregulated ZEB1 and HIF-1α expression was significantly correlated with histological grade, lymphatic metastasis, and distant metastasis in PC patients.

Conclusions

Our results emphasized that the positive reciprocal loop of HIF-1α/ZEB1-AS1/ZEB1/HDAC1 contributes to hypoxia-promoted oncogenicity and PC metastasis, indicating that it might be a novel therapeutic target for PC.

TGFβ Drives Metabolic Perturbations during Epithelial Mesenchymal Transition in Pancreatic Cancer: TGFβ Induced EMT in PDAC

Simple Summary

Pancreatic cancer is an aggressive disease with most patients diagnosed at late stages resulting in poor outcomes. While it is known that pancreatic tumor cells undergo epithelial to mesenchymal transition, the metabolic alterations accompanying that transition are not characterized. This study leveraged a metabolomics approach to understand the small molecule and biochemical perturbations that can be targeted for designing strategies for improving outcomes in pancreatic cancer.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy wherein a majority of patients present metastatic disease at diagnosis. Although the role of epithelial to mesenchymal transition (EMT), mediated by transforming growth factor beta (TGFβ), in imparting an aggressive phenotype to PDAC is well documented, the underlying biochemical pathway perturbations driving this behaviour have not been elucidated. We used high-resolution mass spectrometry (HRMS) based molecular phenotyping approach in order to delineate metabolic changes concomitant to TGFβ-induced EMT in pancreatic cancer cells. Strikingly, we observed robust changes in amino acid and energy metabolism that may contribute to tumor invasion and metastasis. Somewhat unexpectedly, TGFβ treatment resulted in an increase in intracellular levels of retinoic acid (RA) that in turn resulted in increased levels of extracellular matrix (ECM) proteins including fibronectin (FN) and collagen (COL1). These findings were further validated in plasma samples obtained from patients with resectable pancreatic cancer. Taken together, these observations provide novel insights into small molecule dysregulation that triggers a molecular cascade resulting in increased EMT-like changes in pancreatic cancer cells, a paradigm that can be potentially targeted for better clinical outcomes.

EMT-cancer cells-derived exosomal miR-27b-3p promotes circulating tumour cells-mediated metastasis by modulating vascular permeability in colorectal cancer

BACKGROUND

Metastasis is the main cause of death in colorectal cancer (CRC). Circulating tumour cells (CTCs) are regarded as the precursor cells of metastasis. The CTCs, which underwent epithelial-mesenchymal transition (EMT), are associated with metastasis and responsible for poor prognosis. EMT cancer cells modulate endothelial permeability in the invasive front and facilitate cancer cell intravasation, resulting in CTCs-mediated distant metastasis. Exosomes derived from cancer cells are key mediators of cancer-host intercommunication. However, the mechanism by which EMT-tumour cells-derived exosomes modulate vascular permeability and promote CTCs generation has remained unclear.

METHODS

Exosomes isolation and purification were conducted by ultra-centrifugation. Exosomal miRNA was identified by sequencing followed by quantitative PCR. In vitro co-culture assay experiments were conducted to evaluate the effect of exosomal miR-27b-3p on the permeability of blood vessel endothelium. Dual-luciferase reporter assay, chromatin immunoprecipitation (ChIP) and RNA immunoprecipitation (RIP) were performed to investigate the underlying mechanism by which miR-27b-3p is packaged into exosomes. A mouse model was established to determine the role of exosomal miR-27b-3p in blood vessel permeability modulation in vivo.

RESULTS

We found that EMT-CRC cells attenuate the blood vessel barrier by transferring miR-27b-3p to human umbilical vein endothelial cells (HUVECs) in exosomes. Mechanically, miR-27b-3p atteuated the expression of vascular endothelial cadherin (VE-Cad) and p120 at the post-transcriptional level by binding to 3'-untranslated region of VE-Cad and p120 directly. The packaging of miR-27b-3p into exosomes was induced by heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1), which activated by STAT3. Clinically, miR-27b-3p up-regulated in CRC tissues. Plasma exosomal miR-27b-3p was positively correlated with malignant progression and CTC count in CRC patients. Our study reveals a novel mechanism by which EMT-CRC cells promote metastasis, increasing blood vessel permeability and facilitating the generation of CTCs.

CONCLUSION

Exosomal miR-27b-3p secreted by EMT-CRC cells increases blood vessel permeability and facilitates the generation of CTCs. Exosomal miR-27b-3p may become a promising biomarker for CRC metastasis.

Particulate Matter (PM10) Promotes Cell Invasion through Epithelial-Mesenchymal Transition (EMT) by TGF-β Activation in A549 Lung Cells

Air pollution presents a major environmental problem, inducing harmful effects on human health. Particulate matter of 10 μm or less in diameter (PM₁₀) is considered an important risk factor in lung carcinogenesis. Epithelial-mesenchymal transition (EMT) is a regulatory program capable of inducing invasion and metastasis in cancer. In this study, we demonstrated that PM₁₀ treatment induced phosphorylation of SMAD2/3 and upregulation of SMAD4. We also reported that PM₁₀ increased the expression and protein levels of TGFB1 (TGF-β), as well as EMT markers SNAI1 (Snail), SNAI2 (Slug), ZEB1 (ZEB1), CDH2 (N-cadherin), ACTA2 (α-SMA), and VIM (vimentin) in the lung A549 cell line. Cell exposed to PM₁₀ also showed a decrease in the expression of CDH1 (E-cadherin). We also demonstrated that expression levels of these EMT markers were reduced when cells are transfected with small interfering RNAs (siRNAs) against TGFB1. Interestingly, phosphorylation of SMAD2/3 and upregulation of SMAD induced by PM₁₀ were not affected by transfection of TGFB1 siRNAs. Finally, cells treated with PM₁₀ exhibited an increase in the capacity of invasiveness because of EMT induction. Our results provide new evidence regarding the effect of PM₁₀ in EMT and the acquisition of an invasive phenotype, a hallmark necessary for lung cancer progression.

Tumour microenvironment: a non-negligible driver for epithelial-mesenchymal transition in colorectal cancer

Cancer remains the leading cause of death worldwide, and metastasis is still the major cause of treatment failure for cancer patients. Epithelial-mesenchymal transition (EMT) has been shown to play a critical role in the metastasis cascade of epithelium-derived carcinoma. Tumour microenvironment (TME) refers to the local tissue environment in which tumour cells produce and live, including not only tumour cells themselves, but also fibroblasts, immune and inflammatory cells, glial cells and other cells around them, as well as intercellular stroma, micro vessels and infiltrated biomolecules from the nearby areas, which has been proved to widely participate in the occurrence and progress of cancer. Emerging and accumulating studies indicate that, on one hand, mesenchymal cells in TME can establish 'crosstalk' with tumour cells to regulate their EMT programme; on the other, EMT-tumour cells can create a favourable environment for their own growth via educating stromal cells. Recently, our group has conducted a series of studies on the interaction between tumour-associated macrophages (TAMs) and colorectal cancer (CRC) cells in TME, confirming that the interaction between TAMs and CRC cells mediated by cytokines or exosomes can jointly promote the metastasis of CRC by regulating the EMT process of tumour cells and the M2-type polarisation process of TAMs. Herein, we present an overview to describe the current knowledge about EMT in cancer, summarise the important role of TME in EMT, and provide an update on the mechanisms of TME-induced EMT in CRC, aiming to provide new ideas for understanding and resisting tumour metastasis.

Acidic microenvironment enhances MT1-MMP-mediated cancer cell motility through integrin β1/cofilin/F-actin axis

Tumor acidic microenvironment is the main feature of many solid tumors. As a part of the tumor microenvironment, it has a profound impact on the occurrence and development of tumors. However, the research on how tumor cells sense the changes of the external microenvironment and how the intracellular subcellular structures transmit the signals from extracellular to intracellular is unclear. In this study, we identify that the acidic microenvironment enhances cancer cell motility, and the expression of membrane-anchored membrane type 1-matrix metalloproteinase is also associated with cell motility, which indicates more degradation of the ECM under the acidic microenvironment. Moreover, the expression of cofilin is low in the acidic microenvironment, and the F-actin filaments are distributed more along the cells. The cytoskeletal F-actin changes are consistent with the potential of a high-invasive phenotype. Further study reveals the upstream control of the signal transductions from extracellular to intracellular, that is, the integrin β1 functions to trigger the biological responses under the acidic microenvironment. Our results demonstrate that the acidic microenvironment enhances cancer cell motility through the integrin β1/cofilin/F-actin signal axis. This study clearly shows the scheme of the signal transmissions from extracellular to intracellular and further reveals the cytoskeletal roles for the contributions of cancer cell motility under acidic microenvironment, which provides new targets for cancer intervention from the biochemical and biophysical perspectives.

MicroRNA-889-3p restrains the proliferation and epithelial-mesenchymal transformation of lung cancer cells via down-regulation of Homeodomain-interacting protein kinase 1

Dysregulated microRNAs (miRNAs) are common in human cancers and are involved in the proliferation, promotion, and metastasis of tumor cells. Therefore, the aim of this study was to evaluate the expression and biological function of miR-889-3p in lung cancer (LC). MiR-889-3p and Homeodomain-interacting protein kinase 1 (HIPK1) expression was detected in human LC tissues and cells. The correlation of miR-889-3p with the clinicopathology of LC patients was observed. After the transfection of miR-889-3p and HIPK1-related plasmids in human LC cell line A549, several studies were employed for detection of cell growth. In addition, the targeting of miR-889-3p with HIPK1 was verified. The results clarified miR-889-3p was down-regulated, while HIPK1 was up-regulated in LC tissues. Elevated miR-889-3p or repressed HIPK1 weakened the viability, epithelial–mesenchymal transition (EMT), invasion, migration of LC cells, whereas strengthened apoptosis. MiR-889-3p targeted HIPK1; MiR-889-3p mediated HIPK1 to affect the proliferation and EMT of LC cells. Therefore, it is concluded that miR-889-3p repressing HIPK1 restrains the proliferation and EMT of LC cells, providing a novel target for LC therapy.

Epithelial-to-Mesenchymal Plasticity in Circulating Tumor Cell Lines Sequentially Derived from a Patient with Colorectal Cancer

Simple Summary

Metastasis is a complex dynamic multistep process; however, our knowledge is still limited. Very few circulating tumor cells (CTCs) are metastatic precursor cells and represent the intermediate stage of metastasis. Epithelial–mesenchymal plasticity (EMP) has crucial roles in tissue development and homeostasis, and also in metastasis formation. In this study, we explored the EMP phenotype of a unique series of CTC lines, obtained from a patient with colon cancer during the disease course and treatment, by detecting markers involved in the epithelial–mesenchymal and mesenchymal–epithelial (MET) transitions. This study shows that these colon CTC lines have acquired only few mesenchymal features to migrate and intravasate, whereas an increase of MET-related markers was observed, suggesting that metastasis-competent CTCs need to revert quickly to the epithelial phenotype to reinitiate a tumor at a distant site.

Abstract

Metastasis is a complicated and only partially understood multi-step process of cancer progression. A subset of cancer cells that can leave the primary tumor, intravasate, and circulate to reach distant organs are called circulating tumor cells (CTCs). Multiple lines of evidence suggest that in metastatic cancer cells, epithelial and mesenchymal markers are co-expressed to facilitate the cells’ ability to go back and forth between cellular states. This feature is called epithelial-to-mesenchymal plasticity (EMP). CTCs represent a unique source to understand the EMP features in metastatic cascade biology. Our group previously established and characterized nine serial CTC lines from a patient with metastatic colon cancer. Here, we assessed the expression of markers involved in epithelial–mesenchymal (EMT) and mesenchymal–epithelial (MET) transition in these unique CTC lines, to define their EMP profile. We found that the oncogenes MYC and ezrin were expressed by all CTC lines, but not SIX1, one of their common regulators (also an EMT inducer). Moreover, the MET activator GRHL2 and its putative targets were strongly expressed in all CTC lines, revealing their plasticity in favor of an increased MET state that promotes metastasis formation.

Marine bacterial exopolysaccharide EPS11 inhibits migration and invasion of liver cancer cells by directly targeting collagen I

Many natural polysaccharides have significant anticancer activity with low toxicity, but the complex chemical structures make in-depth studies of the involved mechanisms extremely difficult. The purpose of this study was to investigate the effect of the marine bacterial exopolysaccharide (exopolysaccharide 11 [EPS11]) on liver cancer metastasis to explore the underlying target protein and molecular mechanism. We found that EPS11 significantly suppressed cell adhesion, migration, and invasion in liver cancer cells. Proteomic analysis showed that EPS11 induced downregulation of proteins related to the extracellular matrix–receptor interaction signaling pathway. In addition, the direct pharmacological target of EPS11 was identified as collagen I using cellular thermal shift assays. Surface plasmon resonance and pull-down assays further confirmed the specific binding of EPS11 to collagen I. Moreover, EPS11 was shown to inhibit tumor metastasis by directly modulating collagen I activity via the β1-integrin–mediated signaling pathway. Collectively, our study demonstrated for the first time that collagen I could be a direct pharmacological target of polysaccharide drugs. Moreover, directly targeting collagen I may be a promising strategy for finding novel carbohydrate-based drugs.

Photodynamic Therapy for Pancreatic Ductal Adenocarcinoma

Simple Summary

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal of human cancers. Numerous clinical trials evaluating various combinations of chemotherapy and targeted agents and radiotherapy have failed to provide meaningful improvements in survival. A growing number of studies however have indicated that photodynamic therapy (PDT) may be a viable approach for treatment of some pancreatic tumors. PDT, which uses light to activate a photosensitizing agent in target tissue, has seen widespread adoption primarily for dermatological and other applications where superficial light delivery is relatively straightforward. Advances in fiber optic light delivery and dosimetry however have been leveraged to enable PDT even for challenging internal sites, including the pancreas. The aim of this article is to help inform future directions by reviewing relevant literature on the basic science, current clinical status, and potential challenges in the development of PDT as a treatment for PDAC.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal of human cancers. Clinical trials of various chemotherapy, radiotherapy, targeted agents and combination strategies have generally failed to provide meaningful improvement in survival for patients with unresectable disease. Photodynamic therapy (PDT) is a photochemistry-based approach that enables selective cell killing using tumor-localizing agents activated by visible or near-infrared light. In recent years, clinical studies have demonstrated the technical feasibility of PDT for patients with locally advanced PDAC while a growing body of preclinical literature has shown that PDT can overcome drug resistance and target problematic and aggressive disease. Emerging evidence also suggests the ability of PDT to target PDAC stroma, which is known to act as both a barrier to drug delivery and a tumor-promoting signaling partner. Here, we review the literature which indicates an emergent role of PDT in clinical management of PDAC, including the potential for combination with other targeted agents and RNA medicine.

P4HA2 Promotes Epithelial-to-Mesenchymal Transition and Glioma Malignancy through the Collagen-Dependent PI3K/AKT Pathway

Prolyl-4-hydroxylase subunit 2 (P4HA2) is a member of collagen modification enzymes involved in the remodeling of the extracellular matrix (ECM). Mounting evidence has suggested that deregulation of P4HA2 is common in cancer. However, the role of P4HA2 in glioma remains unknown. The present study aimed to elucidate the expression pattern, oncogenic functions, and molecular mechanisms of P4HA2 in glioblastoma cells. The TCGA datasets and paraffin samples were used for examining the expressions of P4HA2. P4HA2-specific lentivirus was generated to assess its oncogenic functions. A P4HA2 enzyme inhibitor (DHB) and an AKT agonist (SC79) were utilized to study the mechanisms. As a result, we demonstrated that P4HA2 is overexpressed in glioma and inversely correlates with patient survival. Knockdown of P4HA2 inhibited proliferation, migration, invasion, and epithelial-to-mesenchymal transition (EMT) like phenotype of glioma cells in vitro and suppressed tumor xenograft growth in vivo. Mechanistically, expressions of a series of collagen genes and of phosphorylated PI3K/AKT were downregulated by either P4HA2 silencing or inhibition of its prolyl hydroxylase. Finally, the inhibitory effects on the migration, invasion, and EMT-related molecules by P4HA2 knockdown were reversed by AKT activation with SC79. Our findings for the first time reveal that P4HA2 acts as an oncogenic molecule in glioma malignancy by regulating the expressions of collagens and the downstream PI3K/AKT signaling pathway.

Mutation SVCT2 promotes cell proliferation, invasion and migration in colorectal cancer

The sodium-dependent vitamin C transporter 2 (SVCT2) surface glycoprotein regulates ascorbate accumulation in the plasma, often resulting in the induction of cancer cell death. Therefore, high expression of this gene associates with increased overall survival in several cancers. However, in colorectal cancer (CRC), high (likely mutated) SVCT2 expression relates to poor overall survival, and its functional significance has not been studied. Thus, we hypothesize that mutant SVCT2 expression could affect CRC patient survival. According to biological databases, SVCT2 has been found to be mutated frequently, and SVCT2 E264K has a particularly high pathogenic score (0.98), compared to other SVCT2 mutant sites, in CRC patients. Interestingly, our results reveal expression of SVCT2 E264K in many CRC tissues and cells. Also, we found wild-type SVCT2 expression to be largely localized to the cytoplasm and membrane, while SVCT2 E264K was restricted to the cytoplasm. We further found that SVCT2 E264K overexpression increases cell growth. By contrast, SVCT2 E264K knockdown significantly reduced cell proliferation and promoted cell apoptosis, resulting in inhibition of cell invasion and migration. Taken together, SVCT2 E264K plays a critical role in proliferation in CRC. Our results suggest that SVCT2 E264K could be a promising novel therapeutic target in CRC.

CtBP modulates Snail-mediated tumor invasion in Drosophila

Cancer is one of the most fatal diseases that threaten human health, whereas more than 90% mortality of cancer patients is caused by tumor metastasis, rather than the growth of primary tumors. Thus, how to effectively control or even reverse the migration of tumor cells is of great significance for cancer therapy. CtBP, a transcriptional cofactor displaying high expression in a variety of human cancers, has become one of the main targets for cancer prediction, diagnosis, and treatment. The roles of CtBP in promoting tumorigenesis have been well studied in vitro, mostly based on gain-of-function, while its physiological functions in tumor invasion and the underlying mechanism remain largely elusive. Snail (Sna) is a well-known transcription factor involved in epithelial-to-mesenchymal transition (EMT) and tumor invasion, yet the mechanism that regulates Sna activity has not been fully understood. Using Drosophila as a model organism, we found that depletion of CtBP or snail (sna) suppressed Ras^V12/lgl^-/--triggered tumor growth and invasion, and disrupted cell polarity-induced invasive cell migration. In addition, loss of CtBP inhibits Ras^V12/Sna-induced tumor invasion and Sna-mediated invasive cell migration. Furthermore, both CtBP and Sna are physiologically required for developmental cell migration during thorax closure. Finally, Sna activates the JNK signaling and promotes JNK-dependent cell invasion. Given that CtBP physically interacts with Sna, our data suggest that CtBP and Sna may form a transcriptional complex that regulates JNK-dependent tumor invasion and cell migration in vivo.

Cancer cell migration in collagen-hyaluronan composite extracellular matrices

Hyaluronan (HA) is a key component in the tumor microenvironment (TME) that participates in cancer growth and invasiveness. While the molecular weight (MW) dependent properties of HA can cause tumor-promoting and -repressing effects, the elevated levels of HA in the TME impedes drug delivery. The degradation of HA using hyaluronidases (HYALs), resulting in fragments of HA, is a way to overcome this, but the consequences of changes in HA molecular weight and concentration is currently unknown. Therefore, it is critical to understand the MW-dependent biological effects of HA. Here we examine the influence of HA molecular weight on biophysical properties that regulate cell migration and extracellular matrix (ECM) remodeling. In our study, we used vLMW, LMW and HMW HA at different physiologically relevant concentrations, with a particular interest in correlating the mechanical and structural properties to different cell functions. The elastic modulus, collagen network pore size and collagen fiber diameter increased with increasing HA concentration. Although the collagen network pore size increased, these pores were filled with the bulky HA molecules. Consequently, cell migration decreased with increase in HA concentration due to multiple, long-lived and unproductive protrusions, suggesting the influence of steric factors. Surprisingly, even though elastic modulus increased with HA molecular weight and concentration, gel compaction assays showed an increased degree of ECM compaction among HMW HA gels at high concentrations (2 and 4 mg mL^-1 [0.2 and 0.4%]). These results were not seen in collagen gels that lacked HA, but had similar stiffness. HA appears to have the effect of decreasing migration and increasing collagen network contraction, but only at high HA molecular weight. Consequently, changes in HA molecular weight can have relatively large effects on cancer cell behavior. STATEMENT OF SIGNIFICANCE: Hyaluronan (HA) is a critical component of the tumor microenvironment (TME). Overproduction of HA in the TME results in poor prognosis and collapse of blood vessels, inhibiting drug delivery. Hyaluronidases have been used to enhance drug delivery. However, they lead to low molecular weight (MW) HA, altering the mechanical and structural properties of the TME and cancer cell behavior. Understanding how HA degradation affects cancer cell behavior is critical for uncovering detrimental effects of this therapy. Very little is known about how HA MW affects cancer cell behavior in tumor-mimicking collagen-HA composite networks. Here we examine how MW and HA content in collagen-HA networks alter structural and mechanical properties to regulate cell migration and matrix remodeling in 3D TME-mimicking environments.

Synergistic AHR Binding Pathway with EMT Effects on Serous Ovarian Tumors Recognized by Multidisciplinary Integrated Analysis

Epithelial ovarian cancers (EOCs) are fatal and obstinate among gynecological malignancies in advanced stage or relapsed status, with serous carcinomas accounting for the vast majority. Unlike EOCs, borderline ovarian tumors (BOTs), including serous BOTs, maintain a semimalignant appearance. Using gene ontology (GO)-based integrative analysis, we analyzed gene set databases of serous BOTs and serous ovarian carcinomas for dysregulated GO terms and pathways and identified multiple differentially expressed genes (DEGs) in various aspects. The SRC (SRC proto-oncogene, non-receptor tyrosine kinase) gene and dysfunctional aryl hydrocarbon receptor (AHR) binding pathway consistently influenced progression-free survival and overall survival, and immunohistochemical staining revealed elevated expression of related biomarkers (SRC, ARNT, and TBP) in serous BOT and ovarian carcinoma samples. Epithelial-mesenchymal transition (EMT) is important during tumorigenesis, and we confirmed the SNAI2 (Snail family transcriptional repressor 2, SLUG) gene showing significantly high performance by immunohistochemistry. During serous ovarian tumor formation, activated AHR in the cytoplasm could cooperate with SRC, enter cell nuclei, bind to AHR nuclear translocator (ARNT) together with TATA-Box Binding Protein (TBP), and act on DNA to initiate AHR-responsive genes to cause tumor or cancer initiation. Additionally, SNAI2 in the tumor microenvironment can facilitate EMT accompanied by tumorigenesis. Although it has not been possible to classify serous BOTs and serous ovarian carcinomas as the same EOC subtype, the key determinants of relevant DEGs (SRC, ARNT, TBP, and SNAI2) found here had a crucial role in the pathogenetic mechanism of both tumor types, implying gradual evolutionary tendencies from serous BOTs to ovarian carcinomas. In the future, targeted therapy could focus on these revealed targets together with precise detection to improve therapeutic effects and patient survival rates.

Fibroblastic galectin-1-fostered invasion and metastasis are mediated by TGF-β1-induced epithelial-mesenchymal transition in gastric cancer

Background The gastric cancer (GC) microenvironment has important effects on biological behaviors, such as tumor cell invasion and metastasis. However, the mechanism by which the GC microenvironment promotes GC cell invasion and metastasis is unknown. The present study aimed to clarify the effects and mechanism of galectin-1 (GAL-1, encoded by LGALS1) on GC invasion and metastasis in the GC microenvironment. Methods The expression of GAL-1/ LGALS1 was determined using western blotting, immunohistochemistry, and quantitative real-time reverse transcription PCR in GC tissues. Besides, methods including stable transfection, Matrigel invasion and migration assays, and wound-healing assays in vitro; and metastasis assays in vivo, were also conducted. Results GAL-1 from cancer-associated fibroblasts (CAFs) induced the epithelial-mesenchymal transition (EMT) of GC cells though the transforming growth factor beta (TGF-β1)/ Sma- and mad-related protein (Smad) pathway, and affected the prognosis of patients with GC. The level of GAL-1 was high in CAFs, and treating MGC-803 and SGC -7901 cell line with the conditioned medium from CAFs promoted their invasion and metastasis abilities. Overexpression of LGALS1 promoted the expression of TGF-β1 and induced EMT of GC cell lines. A TGF-β1 antagonist inhibited the invasion and migration of GC cells. In vivo, overexpression of LGALS1 promoted GC growth and metastasis, and the TGF-β1 antagonist dramatically reversed these events. Conclusions These findings suggested that high expression of GAL-1 in the GC microenvironment predicts a poor prognosis in patients with GC by promoting the migration and invasion of GC cells via EMT through the TGF-β1/Smad signaling pathway. The results might provide new therapeutic targets to treat GC.

Tumor-associated macrophage-derived CCL5 promotes chemotherapy resistance and metastasis in prostatic cancer

The crosstalk between tumor microenvironment and cancer cells is emerging as a critical determinant in tumor progression. However, the underlying mechanism of tumor microenvironment-induced cancer development remains controversial. Here, our study provides evidence to suggest that tumor-associated macrophage (TAM) enrichment is found in chemoresistant prostatic tumor tissues. Those TAMs are demonstrated to promote chemoresistance and distant metastasis in prostatic cancer through secretion of CCL5. Mechanistically, TAM coculture or additional CCL5 can mediate the STAT3-dependent epithelial-mesenchymal transition process, resulting in distant metastasis in prostatic cancer. Meanwhile, activation of STAT3 induced by CCL5 can mediate upregulation of the transcription factor Nanog, leading to drug resistance. In vivo study further demonstrated that blockade of STAT3 signals significantly reverses chemoresistance and suppresses lung metastasis in colorectal tumor-bearing mice, suggesting a novel strategy for clinical prostatic cancer treatment.

The Role of Tumor Inflammatory Microenvironment in Lung Cancer

Lung cancer is the most common and fatal malignant tumor in the world. The tumor microenvironment (TME) is closely related to the occurrence and development of lung cancer, in which the inflammatory microenvironment plays an important role. Inflammatory cells and inflammatory factors in the tumor inflammatory microenvironment promote the activation of the NF-κB and STAT3 inflammatory pathways and the occurrence, development, and metastasis of lung cancer by promoting immune escape, tumor angiogenesis, epithelial-mesenchymal transition, apoptosis, and other mechanisms. Clinical and epidemiological studies have also shown a strong relationship among chronic infection, inflammation, inflammatory microenvironment, and lung cancer. The relationship between inflammation and lung cancer can be better understood through the gradual understanding of the tumor inflammatory microenvironment, which is advantageous to find more therapeutic targets for lung cancer.

Fish Oil, Se Yeast, and Micronutrient-Enriched Nutrition as Adjuvant Treatment during Target Therapy in a Murine Model of Lung Cancer

Despite the effectiveness of primary treatment modalities for cancer, the side effects of treatments, medication resistance, and the deterioration of cachexia after disease progression lead to poor prognosis. A supportive treatment modality to overcome these limitations would be considered a major breakthrough. Here, we used two different target drugs to demonstrate whether a nutraceutical formula (fish oil, Se yeast, and micronutrient-enriched nutrition; NuF) can interfere with cancer cachexia and improve drug efficacy. After Lewis lung cancer (LLC) tumor injection, the C57BL/6 mice were orally administered targeted therapy drugs Iressa and Sutent alone or combined with NuF for 27 days. Sutent administration effectively inhibited tumor size but increased the number of lung metastases in the long term. Sutent combined with NuF had no significant difference in tumor weight and metastasis compare with Sutent alone. However, NuF slightly attenuated metastases number in lung may via mesenchymal marker N-cadherin suppression. NuF otherwise increased epithelial-like marker E-cadherin expression and induce NO-mediated intrinsic apoptotic pathway in tumor cells, thereby strengthening the ability of the targeted therapy drug Iressa for inhibiting tumor progression. Our results demonstrate that NuF can promote the anticancer effect of lung cancer to targeted therapy, especially in Iressa, by inhibiting HIF-1α and epithelial-mesenchymal transition (EMT) and inducing the apoptosis of lung cancer cells. Furthermore, NuF attenuates cancer-related cachectic symptoms by inhibiting systemic oxidative stress.

Phenotypic Heterogeneity of Triple-Negative Breast Cancer Mediated by Epithelial-Mesenchymal Plasticity

Triple-negative breast cancer (TNBC) is a subtype of breast carcinoma known for its unusually aggressive behavior and poor clinical outcome. Besides the lack of molecular targets for therapy and profound intratumoral heterogeneity, the relatively quick overt metastatic spread remains a major obstacle in effective clinical management. The metastatic colonization of distant sites by primary tumor cells is affected by the microenvironment, epigenetic state of particular subclones, and numerous other factors. One of the most prominent processes contributing to the intratumoral heterogeneity is an epithelial-mesenchymal transition (EMT), an evolutionarily conserved developmental program frequently hijacked by tumor cells, strengthening their motile and invasive features. In response to various intrinsic and extrinsic stimuli, malignant cells can revert the EMT state through the mesenchymal-epithelial transition (MET), a process that is believed to be critical for the establishment of macrometastasis at secondary sites. Notably, cancer cells rarely undergo complete EMT and rather exist in a continuum of E/M intermediate states, preserving high levels of plasticity, as demonstrated in primary tumors and, ultimately, in circulating tumor cells, representing a simplified element of the metastatic cascade. In this review, we focus on cellular drivers underlying EMT/MET phenotypic plasticity and its detrimental consequences in the context of TNBC cancer.

Novel agents for the treatment of lymphomas during pregnancy: A comprehensive literature review

Lymphoproliferative diseases occurring during pregnancy present unique diagnostic and therapeutic challenges aiming to achieve maternal cure without impairing fetal health, growth, and survival. These goals are further complicated by the fast-paced emergence of novel therapies and their introduction as standard of care, even in newly diagnosed patients. Due to the rarity of hematological malignancies in pregnancy and the exclusion of pregnancy in almost all clinical trials, available data on the fetal effects of novel drugs are limited to animal models and case reports. The current review addresses the entire multidisciplinary team involved in treating pregnant patients with lymphoproliferative diseases. We describe novel agents according to their mechanism of action, and summarize our knowledge of their effects during the gestational period, particularly those associated with fetotoxicity. Therapeutic dilemmas associated with the employment of these new agents are also discussed.

Expression and Function of ZEB1 in the Cornea

ZEB1 is an important transcription factor for epithelial to mesenchymal transition (EMT) and in the regulation of cell differentiation and transformation. In the cornea, ZEB1 presents in all three layers: the epithelium, the stroma and the endothelium. Mutations of ZEB1 have been linked to multiple corneal genetic defects, particularly to the corneal dystrophies including keratoconus (KD), Fuchs endothelial corneal dystrophy (FECD), and posterior polymorphous corneal dystrophy (PPCD). Accumulating evidence indicates that dysfunction of ZEB1 may affect corneal stem cell homeostasis, and cause corneal cell apoptosis, stromal fibrosis, angiogenesis, squamous metaplasia. Understanding how ZEB1 regulates the initiation and progression of these disorders will help us in targeting ZEB1 for potential avenues to generate therapeutics to treat various ZEB1-related disorders.

TGF-β promote epithelial-mesenchymal transition via NF-κB/NOX4/ROS signal pathway in lung cancer cells

Epithelial-mesenchymal transition (EMT), transforming growth factor β(TGF-β) and reactive oxygen species(ROS) plays a central role in cancer metastasis. Moreover, nicotinamide adenine dinucleotide phosphate 4(NOX4) is one of the main sources of ROS in lung cancer cells suggesting that NOX4 is associated with tumor cell migration. NF-κB(Nuclear factor-Kappa-B) is known to regulate ROS-mediated EMT process by activating Snail transcription factor in A549 cells. The purpose of this study was to explore the relationship between NF-κB and NOX4 in ROS production during TGF-β induced EMT process. Several fractions have been pooled to evaluates the EMT process on lung cancer cells through real-time PCR, Western Blot and flow cytometry with DCFH-DA probe etc. Cells proliferation and migration activities were monitored by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and wound healing assay respectively. The result showed that TGF-β induction decreased the expression of E-cadherin, increased the Vimentin and the EMT transcription factor Snail in A549 cells. DPI (Diphenyleneiodonium chloride, an inhibitor of NOX4) inhibited the NOX4 expression and reduced ROS production induced by TGF-β, but didn't affect the activation of NF-κB induced by TGF-β (P > 0.05). BAY11-7082 (an inhibitor of NF-κB) inhibited the NF-κB (p65) expression and prevented the increase of NOX4 expression and ROS production induced by TGF-β (P < 0.001), which has also verified reduced TGF-β induced cell migration by inhibiting the EMT process, and also reduced cell proliferation of A549 cells (P < 0.001). The current research confirmed the TGF-β mediated EMT process via NF-κB/NOX4/ROS signaling pathway, NF-κB and NOX4 are likely to be the potential therapeutic targets for lung cancer metastasis.

Lung cancer-associated mesenchymal stem cells promote tumor metastasis and tumorigenesis by induction of epithelial-mesenchymal transition and stem-like reprogram

Mesenchymal stem cells (MSCs) have attracted more attention in antitumor therapy by using MSCs as vehicles or targeting modulators of MSCs. But their role and mechanisms in tumor progression are less known. In the present study, we successfully isolated pairs of MSCs from lung cancer (LC-MSCs) and adjacent tumor-free tissues. Based on the coculture system in vitro and animal studies in vivo, we originally found that LC-MSCs significantly promoted tumor metastasis and tumorigenesis both in vitro and in vivo. Partial epithelial–mesenchymal transition (EMT) was induced in lung cancer cells by LC-MSCs by the evidence of remarkable increase in snail and slug expression but not in other EMT-associated genes. The expression of stem related genes also escalated significantly. And spheroids perfectly formed when tumor cells were co-incubated with LC-MSCs. These results revealed a close link of partial EMT and acquisition of stem-like traits in lung cancer cells which was induced by LC-MSCs and greatly promoted metastasis and tumorigenesis in lung cancer. Our findings provided a new insight into LC-MSCs in tumor progression and helped to identify LC-MSCs as a potential vehicle or target for lung cancer therapy.

A Voxel-Based Radiographic Analysis Reveals the Biological Character of Proneural-Mesenchymal Transition in Glioblastoma

Introduction: Proneural and mesenchymal subtypes are the most distinct demarcated categories in classification scheme, and there is often a shift from proneural type to mesenchymal subtype in the progression of glioblastoma (GBM). The molecular characters are determined by specific genomic methods, however, the application of radiography in clinical practice remains to be further studied. Here, we studied the topography features of GBM in proneural subtype, and further demonstrated the survival characteristics and proneural-mesenchymal transition (PMT) progression of samples by combining with the imaging variables.

Methods: Data were acquired from The Cancer Imaging Archive (TCIA, http://cancerimagingarchive.net). The radiography image, clinical variables and transcriptome subtype from 223 samples were used in this study. Proneural and mesenchymal subtype on GBM topography based on overlay and Voxel-based lesion-symptom mapping (VLSM) analysis were revealed. Besides, we carried out the comparison of survival analysis and PMT progression in and outside the VLSM-determined area.

Results: The overlay of total GBM and separated image of proneural and mesenchymal subtype revealed a correlation of the two subtypes. By VLSM analysis, proneural subtype was confirmed to be related to left inferior temporal medulla, and no significant voxel was found for mesenchymal subtype. The subsequent comparison between samples in and outside the VLSM-determined area showed difference in overall survival (OS) time, tumor purity, epithelial-mesenchymal transition (EMT) score and clinical variables.

Conclusions: PMT progression was determined by radiography approach. GBM samples in the VLSM-determined area tended to harbor the signature of proneural subtype. This study provides a valuable VLSM-determined area related to the predilection site, prognosis and PMT progression by the association between GBM topography and molecular characters.

Development and Characterization of Novel Endoxifen-Resistant Breast Cancer Cell Lines Highlight Numerous Differences from Tamoxifen-Resistant Models

Despite the availability of drugs that target ERα-positive breast cancer, resistance commonly occurs, resulting in relapse, metastasis, and death. Tamoxifen remains the most commonly-prescribed endocrine therapy worldwide, and "tamoxifen resistance" has been extensively studied. However, little consideration has been given to the role of endoxifen, the most abundant active tamoxifen metabolite detected in patients, in driving resistance mechanisms. Endoxifen functions differently from the parent drug and other primary metabolites, including 4-hydroxy-tamoxifen (4HT). Many studies have shown that patients who extensively metabolize tamoxifen into endoxifen have superior outcomes relative to patients who do not, supporting a primary role for endoxifen in driving tamoxifen responses. Therefore, "tamoxifen resistance" may be better modeled by "endoxifen resistance" for some patients. Here, we report the development of novel endoxifen-resistant breast cancer cell lines and have extensively compared these models to 4HT and fulvestrant (ICI)-resistant models. Endoxifen-resistant cells were phenotypically and molecularly distinct from 4HT-resistant cells and more closely resembled ICI-resistant cells overall. Specifically, endoxifen resistance was associated with ERα and PR loss, estrogen insensitivity, unique gene signatures, and striking resistance to most FDA-approved second- and third-line therapies. Given these findings, and the importance of endoxifen in the efficacy of tamoxifen therapy, our data indicate that endoxifen-resistant models may be more clinically relevant than existing models and suggest that a better understanding of endoxifen resistance could substantially improve patient care. IMPLICATIONS: Here we report on the development and characterization of the first endoxifen-resistant models and demonstrate that endoxifen resistance may better model tamoxifen resistance in a subset of patients.

Estrogen Receptor α Mediates Doxorubicin Sensitivity in Breast Cancer Cells by Regulating E-Cadherin

Anthracyclines resistance is commonly seen in patients with estrogen receptor α (ERα) positive breast cancer. Epithelial-mesenchymal transition (EMT), which is characterized with the loss of epithelial cell polarity, cell adhesion and acquisition of new invasive property, is considered as one of the mechanisms of chemotherapy-induced drug resistance. In order to identify factors that associated with doxorubicin resistance, we performed in vitro and in vivo experiments using human and mouse breast cancer cell lines with different ERα status. Cell survival experiments revealed that ERα-positive cells (MCF-7 and MCF-7/ADR cell lines), were less sensitive to doxorubicin than ERα-negative (MDA-MB-231, MDA-MB-468) cells, and mouse mammary carcinoma cells (4T-1). The expression of E-cadherin reduced in low-invasive ERα-positive MCF-7 cells after treatment with doxorubicin, indicating epithelial mesenchymal transition. In contrast, the expression of E-cadherin was upregulated in high-invasive ERα-negative cells, showing mesenchymal-epithelial transition (MET). Moreover, it was found that the growth inhibition of 4T-1 cells by doxorubicin was positively correlated with the expression of E-cadherin. In a mouse breast cancer xenograft model, E-cadherin was overexpressed in the primary tumor tissues of the doxorubicin-treated mice. In ERα-positive MCF-7 cells, doxorubicin treatment upregulated the expression of EMT-related transcription factors Snail and Twist, that regulate the expression of E-cadherin. Following overexpression of ERα in ERα-negative cells (MDA-MB-231 and MDA-MB-468), doxorubicin enhanced the upregulation of Snail and Twist, decreased expression of E-cadherin, and decreased the sensitivity of cells to doxorubicin. In contrast, inhibition of ERα activity increased the sensitivity to doxorubicin in ERα-positive MCF-7 cells. These data suggest that the regulation of Snail and/or Twist varies depends on different ERα status. Therefore, doxorubicin combined with anti-estrogen receptor α therapy could improve the treatment efficacy of doxorubicin in ERα-positive breast cancer.

Intraepithelial Lymphocytes Suppress Intestinal Tumor Growth by Cell-to-Cell Contact via CD103/E-Cadherin Signal

BACKGROUND & AIMS

The reason why small intestinal cancer is rarer than colorectal cancer is not clear. We hypothesized that intraepithelial lymphocytes (IELs), which are enriched in the small intestine, are the closest immune cells to epithelial cells, exclude tumor cells via cell-to-cell contact.

METHODS

We developed DPE-green fluorescent protein (DPE-GFP) × adenomatous polyposis coli; multiple intestinal neoplasia (APC^min ) mice, which is a T-cell-reporter mouse with spontaneous intestinal tumors. We visualized the dynamics of IELs in the intestinal tumor microenvironment and the interaction between IELs and epithelial cells, and the roles of cell-to-cell contact in anti-intestinal tumor immunity using a novel in vivo live-imaging system and a novel in vitro co-culture system.

RESULTS

In the small intestinal tumor microenvironment, T-cell movement was restricted around blood vessels and the frequency of interaction between IELs and epithelial cells was reduced. Genetic deletion of CD103 decreased the frequency of interaction between IELs and epithelial cells, and increased the number of small intestinal tumors. In the co-culture system, wild-type IELs expanded and infiltrated to intestinal tumor organoids from APC^min mice and reduced the viability of them, which was cell-to-cell contact and CD103 dependent.

CONCLUSIONS

The abundance of IELs in the small intestine may contribute to a low number of tumors, although this system may not work in the colon because of the sparseness of IELs. Strategies to increase the number of IELs in the colon or enhance cell-to-cell contact between IELs and epithelial cells may be effective for the prevention of intestinal tumors in patients with a high cancer risk.

Hypoxia promotes the metastasis of pancreatic cancer through regulating NOX4/KDM5A-mediated histone methylation modification changes in a HIF1A-independent manner

Background

Hypoxia is a characteristic of the tumor microenvironments within pancreatic cancer (PC), which has been linked to its malignancy. Recently, hypoxia has been reported to regulate the activity of important carcinogenic pathways by changing the status of histone modification. NOX4, a member of NADPH oxidase (NOX), has been found to be activated by hypoxia and promote cancer progression in several cancers. But whether it is involved in the epigenetic changes of tumor cells induced by hypoxia is still unclear, and its biological roles in PC also need to be explored.

Methods

A hypoxic-related gene signature and its associated pathways in PC were identified by analyzing the pancreatic cancer gene expression data from GEO and TCGA database. Candidate downstream gene (NOX4), responding to hypoxia, was validated by RT-PCR and western blot. Then, we evaluated the relationship between NOX4 expression and clinicopathologic parameters in 56 PC patients from our center. In vitro and in vivo assays were preformed to explore the phenotype of NOX4 in PC. Immunofluorescence, western blot and chromatin immunoprecipitation assays were further applied to search for a detailed mechanism.

Results

We quantified hypoxia and developed a hypoxia signature, which was associated with worse prognosis and elevated malignant potential in PC. Furthermore, we found that NADPH oxidase 4 (NOX4), which was induced by hypoxia and upregulated in PC in a HIF1A-independent manner, caused inactivation of lysine demethylase 5A (KDM5A), increased the methylation modification of histone H3 and regulated the transcription of EMT-associated gene_ snail family transcriptional repressor 1 (SNAIL1). This served to promote the invasion and metastasis of PC. NOX4 deficiency repressed hypoxia-induced EMT, reduced expression of H3K4ME3 and impaired the invasion and metastasis of PC cells; however, knockdown of KDM5A reversed the poor expression of H3KEME3 induced by NOX4 deficiency, thereby promoting EMT.

Conclusions

This study highlights the prognostic role of hypoxia-related genes in PC and strong correlation with EMT pathway. Our results also creatively discovered that NOX4 was an essential mediator for hypoxia-induced histone methylation modification and EMT in PC cells.

Exosomal Long Non-Coding RNA: Interaction Between Cancer Cells and Non-Cancer Cells

Exosomes are small membranous vesicles released by many kinds of cells, and are indispensable in cell-to-cell communication by delivering functional biological components both locally and systemically. Long non-coding RNAs (lncRNAs) are long transcripts over 200 nucleotides that exhibit no or limited protein-coding potentials. LncRNAs are dramatic gene expression regulators, and can be selectively sorted into exosomes. Exosomal lncRNAs derived from cancer cells and stromal cells can mediate the generation of pre-metastatic niches (PMNs) and thus promote the progression of cancer. In this review, we summarized the fundamental biology and characteristics of exosomal lncRNAs. Besides, we provided an overview of current research on functions of exosomal lncRNAs between cancer cells and non-cancer cells. A deep understanding of exosomal lncRNAs' role in cancer will be facilitated to find important implications for cancer development and treatment.

Upregulation of LAMB1 via ERK/c-Jun Axis Promotes Gastric Cancer Growth and Motility

Gastric cancer is the fifth most common cancer worldwide with a poor survival rate. Therefore, it is important to identify predictive and prognostic biomarkers of gastric cancer. Laminin subunit beta 1 (LAMB1) is involved in attachment, migration, and organization during development, and its elevated expression has been associated with several cancers. However, the role and mechanism of LAMB1 in gastric cancer remains unknown. Here, we determined that LAMB1 is upregulated in gastric cancer tissues and contributes to cell growth and motility. Using a public database, we showed that LAMB1 expression was significantly upregulated in gastric cancer compared to normal tissues. LAMB1 was also found to be associated with poor prognosis in patients with gastric cancer. Overexpression of LAMB1 elevated cell proliferation, invasion, and migration; however, knockdown of LAMB1 decreased these effects in gastric cancer cells. U0126, an extracellular signal-regulated kinase (ERK) inhibitor, regulated the expression of LAMB1 in gastric cancer cells. Additionally, we showed that c-Jun directly binds to the LAMB1 promoter as a transcription factor and regulates its gene expression via the ERK pathway in gastric cancer cells. Therefore, our study indicates that LAMB1 promotes cell growth and motility via the ERK/c-Jun axis and is a potential biomarker and therapeutic target of gastric cancer.

LINC00941 promotes CRC metastasis through preventing SMAD4 protein degradation and activating the TGF-β/SMAD2/3 signaling pathway

ABSTRICT

LINC00941 is a novel lncRNA that has been found to exhibit protumorigenic and prometastatic behaviors during tumorigenesis. However, its role in metastatic CRC remains unknown. We aimed to investigate the functions and mechanisms of LINC00941 in CRC metastasis. LINC00941 was shown to be upregulated in CRC, and upregulated LINC00941 was associated with poor prognosis. Functionally, LINC00941 promoted migratory and invasive capacities and accelerated lung metastasis in nude mice. Mechanistically, LINC00941 activated EMT in CRC cells, as indicated by the increased expression of key molecular markers of cell invasion and metastasis (Vimentin, Fibronectin, and Twist1) and simultaneous decreased expression of the main invasion suppressors E-cadherin and ZO-1. LINC00941 was found to activate EMT by directly binding the SMAD4 protein MH2 domain and competing with β-TrCP to prevent SMAD4 protein degradation, thus activating the TGF-β/SMAD2/3 signaling pathway. Our data reveal the essential role of LINC00941 in metastatic CRC via activation of the TGF-β/SMAD2/3 axis, which provides new insight into the mechanism of metastatic CRC and a novel potential therapeutic target for advanced CRC.

C-Reactive Protein and Cancer-Diagnostic and Therapeutic Insights

Cancer disease describes any pathology involving uncontrolled cell growth. As cells duplicate, they can remain localized in defined tissues, forming tumor masses and altering their microenvironmental niche, or they can disseminate throughout the body in a metastatic process affecting multiple tissues and organs. As tumors grow and metastasize, they affect normal tissue integrity and homeostasis which signals the body to trigger the acute phase inflammatory response. C-reactive protein (CRP) is a predominant protein of the acute phase response; its blood levels have long been used as a minimally invasive index of any ongoing inflammatory response, including that occurring in cancer. Its diagnostic significance in assessing disease progression or remission, however, remains undefined. By considering the recent understanding that CRP exists in multiple isoforms with distinct biological activities, a unified model is advanced that describes the relevance of CRP as a mediator of host defense responses in cancer. CRP in its monomeric, modified isoform (mCRP) modulates inflammatory responses by inserting into activated cell membranes and stimulating platelet and leukocyte responses associated with acute phase responses to tumor growth. It also binds components of the extracellular matrix in involved tissues. Conversely, CRP in its pentameric isoform (pCRP), which is the form quantified in diagnostic measurements of CRP, is notably less bioactive with weak anti-inflammatory bioactivity. Its accumulation in blood is associated with a continuous, low-level inflammatory response and is indicative of unresolved and advancing disease, as occurs in cancer. Herein, a novel interpretation of the diagnostic utility of CRP is presented accounting for the unique properties of the CRP isoforms in the context of the developing pro-metastatic tumor microenvironment.

HOX Genes Family and Cancer: A Novel Role for Homeobox B9 in the Resistance to Anti-Angiogenic Therapies

Simple Summary

The inhibition of angiogenesis, relying on the use of drugs targeting the VEGF signaling pathway, has become one of the main strategies for cancer treatment. However, the intrinsic and acquired resistance to this type of therapy limit its efficacy. Thus, the identification of novel therapeutic targets is urgently needed. The resistance to anti-angiogenic treatment often occurs through the activation of alternative VEGF independent signaling pathways and recruitment of bone marrow-derived pro-angiogenic cells in the tumor microenvironment. HOX genes are key regulators of embryonic development, also involved in angiogenesis and in cancer progression. HOXB9 upregulation occurs in many types of cancer and it has been identified as a critical transcription factor involved in tumour resistance to anti-angiogenic drugs. Indeed, HOXB9 modulates the expression of alternative pro-angiogenic secreted factors in the tumour microenvironment leading tumor escape from the anti-angiogenic treatments. Hence, HOXB9 could serves as a novel therapeutic target to overcome the resistance to anti-angiogenic therapies.

Abstract

Angiogenesis is one of the hallmarks of cancer, and the inhibition of pro-angiogenic factors and or their receptors has become a primary strategy for cancer therapy. However, despite promising results in preclinical studies, the majority of patients either do not respond to these treatments or, after an initial period of response, they develop resistance to anti-angiogenic agents. Thus, the identification of a novel therapeutic target is urgently needed. Multiple mechanisms of resistance to anti-angiogenic therapy have been identified, including the upregulation of alternative angiogenic pathways and the recruitment of pro-angiogenic myeloid cells in the tumor microenvironment. Homeobox containing (HOX) genes are master regulators of embryonic development playing a pivotal role during both embryonic vasculogenesis and pathological angiogenesis in adults. The importance of HOX genes during cancer progression has been reported in many studies. In this review we will give a brief description of the HOX genes and their involvement in angiogenesis and cancer, with particular emphasis on HOXB9 as a possible novel target for anti-angiogenic therapy. HOXB9 upregulation has been reported in many types of cancers and it has been identified as a critical transcription factor involved in resistance to anti-angiogenic drugs.

Atmospheric fine particulate matter and epithelial mesenchymal transition in pulmonary cells: state of the art and critical review of the in vitro studies

Exposure to fine particulate matter (PM_2.5) has been associated with several diseases including asthma, chronic obstructive pulmonary disease (COPD) and lung cancer. Mechanisms such as oxidative stress and inflammation are well-documented and are considered as the starting point of some of the pathological responses. However, a number of studies also focused on epithelial-mesenchymal transition (EMT), which is a biological process involved in fibrotic diseases and cancer progression notably via metastasis induction. Up until now, EMT was widely reported in vivo and in vitro in various cell types but investigations dealing with in vitro studies of PM_2.5 induced EMT in pulmonary cells are limited. Further, few investigations combined the necessary endpoints for validation of the EMT state in cells: such as expression of several surface, cytoskeleton or extracellular matrix biomarkers and activation of transcription markers and epigenetic factors. Studies explored various cell types, cultured under differing conditions and exposed for various durations to different doses. Such unharmonized protocols (1) might introduce bias, (2) make difficult comparison of results and (3) preclude reaching a definitive conclusion regarding the ability of airborne PM_2.5 to induce EMT in pulmonary cells. Some questions remain, in particular the specific PM_2.5 components responsible for EMT triggering. The aim of this review is to examine the available PM_2.5 induced EMT in vitro studies on pulmonary cells with special emphasis on the critical parameters considered to carry out future research in this field. This clarification appears necessary for production of reliable and comparable results.

Zeb1 expression by tumor or stromal cells is associated with spatial distribution patterns of CD8+ tumor-infiltrating lymphocytes: a hypothesis-generating study on 113 triple negative breast cancers

Spatial organization of tumor microenvironment (TME) may influence tumor response to immunomodulatory therapies. Zeb1 is a driver of epithelial-mesenchymal transition, with several roles in immune cell development, however its role in shaping of the immune TME is not fully explored. We conducted a pre-multiplex spatial analysis study to verify whether Zeb1 influences spatial distribution of tumor-infiltrating lymphocytes (TILs) in triple negative breast cancer (TNBC). We applied single and double immunohistochemistry to analyze spatial relationships between CD8+, FoxP3+ and CD20+ tumor-infiltrating lymphocytes (TILs) and the cells expressing Zeb1 in formalin-fixed, paraffin-embedded surgical specimens of 113 TNBCs. 15.5% of cases had Zeb1+ tumor cells and 72.8% of cases had stroma rich in Zeb1+ cells. Low density of intratumoral CD8+ TILs was observed in almost all TNBCs with high or moderate Zeb1+ expression in tumor cells (22/23 cases, 95.6%), and in 90.4% of TNBCs (75/83 cases) with stroma rich in Zeb1+ cells. On the other side, a majority of TNBCs with stroma rich in Zeb1+ cells had high density of stromal CD8+ TILs (55/83 cases, 66.3%). These associations were not observed between Zeb1-expressing cells and FoxP3+ or CD20+ TILs. This in situ analysis showed specific spatial relationship between tumor or stromal Zeb1+ cells and CD8+ TILs, which need to be validated in other cohorts. Zeb1 was highlighted both as a marker of tumor cell EMT and of tumor stroma richness in mesenchymal cells. Several hypotheses about causes of the observed relationship between Zeb1 and TILs are generated and the approaches to verify them discussed. Zeb1 is worth further investigation as a potential biomarker of intratumor immunosuppression of TNBC and of its response to immunotherapies.

Classifying the Linkage between Adipose Tissue Inflammation and Tumor Growth through Cancer-Associated Adipocytes

Recently, tumor microenvironment (TME) and its stromal constituents have provided profound insights into understanding alterations in tumor behavior. After each identification regarding the unique roles of TME compartments, non-malignant stromal cells are found to provide a sufficient tumorigenic niche for cancer cells. Of these TME constituents, adipocytes represent a dynamic population mediating endocrine effects to facilitate the crosstalk between cancer cells and distant organs, as well as the interplay with nearby tumor cells. To date, the prevalence of obesity has emphasized the significance of metabolic homeostasis along with adipose tissue (AT) inflammation, cancer incidence, and multiple pathological disorders. In this review, we summarized distinct characteristics of hypertrophic adipocytes and cancer to highlight the importance of an individual's metabolic health during cancer therapy. As AT undergoes inflammatory alterations inducing tissue remodeling, immune cell infiltration, and vascularization, these features directly influence the TME by favoring tumor progression. A comparison between inflammatory AT and progressing cancer could potentially provide crucial insights into delineating the complex communication network between uncontrolled hyperplastic tumors and their microenvironmental components. In turn, the comparison will unravel the underlying properties of dynamic tumor behavior, advocating possible therapeutic targets within TME constituents.

MicroRNA-885 regulates the growth and epithelial mesenchymal transition of human liver cancer cells by suppressing tropomodulin 1 expression

MicroRNA-885 (miR-885) has been shown to act as vital regulator of tumorigenesis and its tumor-suppressive role has been investigated in several human cancers. However, the role of miR-885 in regulation of epithelial mesenchymal transition of liver cancer cells yet unknown. This study was undertaken to investigate the tumor-suppressive role of miR-885 and investigate its effects on epithelial mesenchymal transition of human liver cancer cells. The results revealed that miR-885 to be significantly (P < 0.05) repressed in liver cancer and tissues and cell lines. Overexpression of miR-885 resulted in significant (P < 0.05) decline in the proliferation of liver cancer cells. Additionally, migration and invasion of the liver cancer cells was also suppressed upon miR-182 overexpression which was associated with alteration of the proteins associated with epithelial mesenchymal transition. TMOD1 was identified as the target of miR-885 and the regulatory role of miR-885 was elucidated to be exerted via post-transcriptional silencing of TMOD1. The silencing of TMOD1 by miR-885 inhibited the expression of mesenchymal markers but enhanced the expression levels of epithelial markers. The results of present study revealed miR-885 proved the tumor-suppressive role of miR-885 in liver cancer and points towards its therapeutic implications in liver cancer management.

Intrinsic and Extrinsic Modulators of the Epithelial to Mesenchymal Transition: Driving the Fate of Tumor Microenvironment

The epithelial to mesenchymal transition (EMT) is an evolutionarily conserved process. In cancer, EMT can activate biochemical changes in tumor cells that enable the destruction of the cellular polarity, leading to the acquisition of invasive capabilities. EMT regulation can be triggered by intrinsic and extrinsic signaling, allowing the tumor to adapt to the microenvironment demand in the different stages of tumor progression. In concomitance, tumor cells undergoing EMT actively interact with the surrounding tumor microenvironment (TME) constituted by cell components and extracellular matrix as well as cell secretome elements. As a result, the TME is in turn modulated by the EMT process toward an aggressive behavior. The current review presents the intrinsic and extrinsic modulators of EMT and their relationship with the TME, focusing on the non-cell-derived components, such as secreted metabolites, extracellular matrix, as well as extracellular vesicles. Moreover, we explore how these modulators can be suitable targets for anticancer therapy and personalized medicine.

Epithelial-Mesenchymal Transition: Role in Cancer Progression and the Perspectives of Antitumor Treatment

About 90% of all malignant tumors are of epithelial nature. The epithelial tissue is characterized by a close interconnection between cells through cell-cell interactions, as well as a tight connection with the basement membrane, which is responsible for cell polarity. These interactions strictly determine the location of epithelial cells within the body and are seemingly in conflict with the metastatic potential that many cancers possess (the main criteria for highly malignant tumors). Tumor dissemination into vital organs is one of the primary causes of death in patients with cancer. Tumor dissemination is based on the so-called epithelial-mesenchymal transition (EMT), a process when epithelial cells are transformed into mesenchymal cells possessing high mobility and migration potential. More and more studies elucidating the role of the EMT in metastasis and other aspects of tumor progression are published each year, thus forming a promising field of cancer research. In this review, we examine the most recent data on the intracellular and extracellular molecular mechanisms that activate EMT and the role they play in various aspects of tumor progression, such as metastasis, apoptotic resistance, and immune evasion, aspects that have usually been attributed exclusively to cancer stem cells (CSCs). In conclusion, we provide a detailed review of the approved and promising drugs for cancer therapy that target the components of the EMT signaling pathways.

Relationship of tumour-associated macrophages with poor prognosis in Wilms' tumour

BACKGROUND

Wilms' tumour (WT) is the most common childhood renal tumour. Tumour-associated macrophages (TAMs) are a critical component of tumour microenvironments and contain two main subtypes, classically (M1) or alternatively (M2) activated macrophages. Evidence has revealed TAMs in predicting poor prognosis in some malignant tumours. However, the role of TAMs in WT is still unclear, and the relationship of different types of TAMs with prognosis has not been elucidated.

OBJECTIVE

The aim of the study was to explore the presence of two types of TAMs in WT and analyse the relationship of TAMs with prognosis.

STUDY DESIGN

Overall, 61 paediatric patients with WT underwent nephrectomy before any chemotherapy from April 2006 to March 2014. The tumour tissues were analysed by Western blot, immunohistochemistry, and immunofluorescence to explore the distribution of M1 and M2 macrophages in different stages. Kaplan-Meier analysis with regard to the relationship between the presence of TAMs and follow-up information was performed.

RESULTS

In the 61 patients (44 males and 17 females), there was a median age of 19 months (IQR 13-35.5); 47 patients are still alive, 11 died, 3 were lost to follow-up. According to the National Wilms Tumor Study (NWTS)-5 guidelines, the distribution of tumour stages was as follows: stage I, 27 patients; stage II, 18 patients; and stage III, 16 patients. The Western blot analysis showed that the density of M1 and M2 macrophages in tumour tissues were significantly greater than that in adjacent normal tissues. Immunohistochemistry showed the proportion of patients with positive M1-type macrophages across different stages: stage I, 66.7% (18/27); stage II, 44.4% (8/18); and stage III, 25% (4/16) (p = 0.027). The proportion of patients with positive M2-type macrophages across different stages: stage I, 25.9% (7/27); stage II, 55.6% (10/18); and stage III, 81.3% (13/16) (p = 0.002). Kaplan-Meier analysis suggested that patients with high densities of M2-type macrophages had shorter overall survival time than those with low densities (log-rank test, p = 0.011).

DISCUSSION

TAMs play a pivotal comments in the tumour microenvironment and tumorigenesis. With the progression of clinical stage, M2 macrophage densities increased greatly, and M1 macrophage density decreased. M2 macrophages represent a poor prognosis and can be utilized as a new indicator in pathological examination.

CONCLUSION

There is a high density of TAMs in WT, and M2-type macrophage density increases with tumour progression and implies a poor prognosis.

3D porous chitosan-chondroitin sulfate scaffolds promote epithelial to mesenchymal transition in prostate cancer cells

Prostate cancer (PCa) is a common cancer in men that is curable prior to metastasis, when its prognosis worsens. Chondroitin sulfate (CS) is found in the extracellular matrix of normal prostate tissue and PCa, with greater content in metastatic PCa. Biomaterial scaffolds containing CS have yet to be evaluated for tumor microenvironment applications. Three-dimensional porous chitosan-CS (C-CS) scaffolds were developed and evaluated for PCa culture. Three C-CS scaffold compositions were prepared with 4 w/v% chitosan and 0.1, 0.5, and 1.0 w/v% CS and named 4-0.1, 4-0.5, and 4-1, respectively. The C-CS scaffolds had 90-95% porosity, average pore sizes between 143 and 166 μm, and no significant difference in scaffold stiffness. PC-3 and 22Rv1 PCa cells were cultured on the C-CS scaffolds to study the effect of CS on PCa growth and epithelial to mesenchymal transition (EMT). All C-CS scaffold compositions supported PCa growth and the 4-1 scaffolds had the greatest cell numbers for both PC-3 and 22Rv1. The C-CS scaffolds promoted upregulated EMT marker expression compared to 2D cultures with the greatest EMT marker expression in 4-1 scaffolds. Increasing CS concentration promoted upregulated vimentin expression in PC-3 cultures and N-cadherin and MMP-2 expression in 22Rv1 cultures. C-CS scaffolds promoted docetaxel drug resistance in PC-3 and 22Rv1 cultures and the 4-1 scaffold cultures had the greatest drug resistance. These results indicate that C-CS scaffolds are a promising in vitro platform for PCa.

The versatile roles and clinical implications of exosomal mRNAs and microRNAs in cancer

Extracellular vesicles (EVs), which include exosomes, microvesicles, and apoptotic bodies, are nanosized structures that are secreted by various cells and act as important mediators in intercellular communication. Recent studies have shown that exosomes carrying bioactive molecules are generated from multivesicular bodies and are present in various body fluids. mRNAs and microRNAs (miRNAs) are encapsulated in exosomes and have been found to be involved in multiple pathophysiological processes. Here, we provide a review of tumor-associated exosomal mRNAs and miRNAs and their roles in metastasis and drug resistance. In particular, we emphasize their clinical application potential as diagnostic and prognostic biomarkers of cancer and in cancer therapy.

Permissive State of EMT: The Role of Immune Cell Compartment

The Epithelial to Mesenchymal Transition (EMT) type 3 is a reversible dynamic process recognized as a major determinant of the metastatic event, although many questions regarding its role throughout this process remain unanswered. The ability of cancer cells to migrate and colonize distant organs is a key aspect of tumor progression and evolution, requiring constant tumor cells and tumor microenvironment (TME) changes, as well as constant changes affecting the cross-talk between the two aforementioned compartments. Alterations affecting tumor cells, such as transcription factors, trans-membrane receptors, chromatin remodeling complexes and metabolic pathways, leading to the disappearance of the epithelial phenotype and concomitant gaining of the undifferentiated mesenchymal phenotype are undoubtedly major players of the EMT process. However, several lines of evidence point out toward a more critical role of TME composition in creating an “EMT-permissive state.” The “EMT-permissive state” consists in changes affecting physical and biochemical properties (i.e., stiffness and/or hypoxia) as well as changes of the TME cellular component (i.e., immune-cell, blood vessel, lymphatic vessels, fibroblasts, and fat cells) that favor and induce the epithelial mesenchymal transition. In this mini review, we will discuss the role of the tumor microenvironment cellular component that are involved in supporting the EMT, with particular emphasis on the immune-inflammatory cells component.