EMT Transition States during Tumor Progression and Metastasis

ΕGFR/ERβ-Mediated Cell Morphology and Invasion Capacity Are Associated with Matrix Culture Substrates in Breast Cancer

Breast cancer accounts for almost one in four cancer diagnoses in women. Studies in breast cancer patients have identified several molecular markers, indicators of aggressiveness, which help toward more individual therapeutic approaches. In triple-negative breast cancer (TNBC), epidermal growth factor receptor (EGFR) overexpression is associated with increased metastatic potential and worst survival rates. Specifically, abnormal EGFR activation leads to altered matrix metalloproteinases' (MMPs) expression and, hence, extracellular matrix (ECM) degradation, resulting in induced migration and invasion. The use of matrix substrates for cell culture gives the opportunity to mimic the natural growth conditions of the cells and their microenvironment, as well as cell-cell and cell-matrix interactions. The aim of this study was to evaluate the impact of EGFR inhibition, estrogen receptor beta (ERβ) and different matrix substrates [type I collagen and fibronectin (FN)] on the functional properties, expression of MMPs and cell morphology of ERβ-positive TNBC cells and shERβ ones. Our results highlight EGFR as a crucial regulator of the expression and activity levels of MMPs, while ERβ emerges as a mediator of MMP7 and MT1-MMP expression. In addition, the EGFR/ERβ axis impacts the adhesion and invasion potential of breast cancer cells on collagen type I. Images obtained by scanning electron microscope (SEM) from cultures on the different matrix substrates revealed novel observations regarding various structures of breast cancer cells (filopodia, extravesicles, tunneling nanotubes, etc.). Moreover, the significant contribution of EGFR and ERβ in the morphological characteristics of these cells is also demonstrated, hence highlighting the possibility of dual pharmacological targeting.

In primary airway epithelial cells, the unjamming transition is distinct from the epithelial-to-mesenchymal transition

The epithelial-to-mesenchymal transition (EMT) and the unjamming transition (UJT) each comprises a gateway to cellular migration, plasticity and remodeling, but the extent to which these core programs are distinct, overlapping, or identical has remained undefined. Here, we triggered partial EMT (pEMT) or UJT in differentiated primary human bronchial epithelial cells. After triggering UJT, cell-cell junctions, apico-basal polarity, and barrier function remain intact, cells elongate and align into cooperative migratory packs, and mesenchymal markers of EMT remain unapparent. After triggering pEMT these and other metrics of UJT versus pEMT diverge. A computational model attributes effects of pEMT mainly to diminished junctional tension but attributes those of UJT mainly to augmented cellular propulsion. Through the actions of UJT and pEMT working independently, sequentially, or interactively, those tissues that are subject to development, injury, or disease become endowed with rich mechanisms for cellular migration, plasticity, self-repair, and regeneration.

Overexpression of PKMYT1 Facilitates Tumor Development and Is Correlated with Poor Prognosis in Clear Cell Renal Cell Carcinoma

BACKGROUND Protein kinase membrane-associated tyrosine/threonine (PKMYT1) has been found in many tumors, but its association with clear cell renal cell carcinoma (ccRCC) remains unclear. MATERIAL AND METHODS PKMYT1 expression in ccRCC was examined in the Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and Tumor Immune Estimation Resource databases. The correlation between PKMYT1 expression and clinicopathological parameters was explored via the chi-square test. Receiver operating characteristic curves were used to estimate the diagnostic performance of PKMYT1. Kaplan-Meier curves, a Cox model, nomogram, time-dependent receiver operating characteristic curves, and decision curve analysis (DCA) were used to evaluate the prognostic value and clinical utility of PKMYT1. Genes coexpressed with PKMYT1 in ccRCC were identified based on TCGA, the gene expression profiling interactive, and cBioPortal. Gene Set Enrichment Analysis revealed biological pathways associated with PKMYT1 in ccRCC. RESULTS Weighted gene coexpression network analysis identified PKMYT1 as one of the genes most significantly correlated with progression of histological grade. PKMYT1 was significantly upregulated in ccRCC compared with normal tissue (P<0.001), with a trend toward differentiating between individuals with ccRCC and those who were healthy (area under the curve=0.942). High PKMYT1 expression was correlated with unsatisfactory survival (hazard ratio=1.67, P=0.001), indicating that it is a risk factor for ccRCC. A nomogram incorporating PKMYT1 level was created and showed a clinical net benefit. PKMYT1 was strongly positively correlated with the anti-silencing function of 1B histone chaperone (ASF1B) gene in ccRCC. CONCLUSIONS PKMYT1 is upregulated in ccRCC and its presence indicates poor prognosis, making it a potential therapeutic target for ccRCC.

Emerging role of tumor cell plasticity in modifying therapeutic response

Resistance to cancer therapy is a major barrier to cancer management. Conventional views have proposed that acquisition of resistance may result from genetic mutations. However, accumulating evidence implicates a key role of non-mutational resistance mechanisms underlying drug tolerance, the latter of which is the focus that will be discussed here. Such non-mutational processes are largely driven by tumor cell plasticity, which renders tumor cells insusceptible to the drug-targeted pathway, thereby facilitating the tumor cell survival and growth. The concept of tumor cell plasticity highlights the significance of re-activation of developmental programs that are closely correlated with epithelial-mesenchymal transition, acquisition properties of cancer stem cells, and trans-differentiation potential during drug exposure. From observations in various cancers, this concept provides an opportunity for investigating the nature of anticancer drug resistance. Over the years, our understanding of the emerging role of phenotype switching in modifying therapeutic response has considerably increased. This expanded knowledge of tumor cell plasticity contributes to developing novel therapeutic strategies or combination therapy regimens using available anticancer drugs, which are likely to improve patient outcomes in clinical practice.

miR-876 Inhibits EMT and Liver Fibrosis via POSTN to Suppress Metastasis in Hepatocellular Carcinoma

Background

The asymptomatic onset, frequent recurrence, and poor prognosis of hepatocellular carcinoma (HCC) prompted us to identify new therapeutic targets or predictive markers of HCC diagnosis or prognosis.

Methods

In this study, bioinformatics analysis was used to screen for target miRNAs from the open-access TCGA database. Transwell assays, Western blotting, and qRT-PCR analyses were used to detect cellular functions and gene expression in HCC cells and samples. A nude mouse tumorigenesis model was established to facilitate the observation of HCC progression. Other assays included luciferase reporter assays, IHC, and survival analysis.

Results

We found that the identified miR-876 from TCGA was expressed at low levels in HCC cell lines and that low miR-876 expression was corrected with liver cirrhosis, tumor thrombus, and TNM stage. Further research revealed that miR-876 regulated cell invasion, EMT, and collagen expression by targeting POSTN expression. miR-876 and POSTN were inversely correlated in HCC samples and associated with EMT status and liver fibrosis in clinical HCC tissues. miR-876 inhibited the liver cancer progression in in vivo animal assays. Finally, both miR-876 and POSTN were risk factors for HCC survival, and HCC patients with combined low miR-876 and high POSTN expression had worse prognosis.

Conclusions

miR-876 inhibited HCC EMT and fibrosis by targeting POSTN, thus affecting HCC progression and prognosis. miR-876 and POSTN may be useful therapeutic targets or prognostic markers of HCC.

Topoisomerase II alpha promotes gallbladder cancer proliferation and metastasis through activating phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway

BACKGROUND

Topoisomerase II alpha (TOP2A) has been reported to play a crucial role in the tumorigenesis of various cancer types. However, the biological role of TOP2A in gallbladder cancer (GBC) remains unknown. The current study aimed to explore the function and potential mechanism of TOP2A in GBC.

METHODS

Based on Gene Expression Profiling Interactive Analysis data, we found TOP2A was significantly up-regulated in GBC tissues and resulting in shorter overall survival. Quantitative real-time polymerase chain reaction and immunohistochemistry were conducted to detect the expression of TOP2A in 45 pairs of GBC tissues and adjacent non-tumor tissues. In vitro, cell proliferation, migration, and invasion ability were examined by cell counting kit-8 and transwell assay, respectively. Epithelial-mesenchymal transition (EMT) related and phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway-related markers were measured by Western blotting. Xenograft model assay was performed to evaluate the effect of TOP2A in vivo.

RESULTS

TOP2A was found up-regulated in GBC (tumor vs. normal, 12.62 vs. 0.34) and correlated with the late tumor node metastasis stage (P = 0.0032), present of lymph node metastasis (P = 0.0273), and poor prognosis in GBC patients (log-rank P = 0.028). In vitro and in vivo assays showed that knockdown of TOP2A notably inhibited cell proliferation, migration, invasion, EMT process, and tumor growth in GBC. In addition, TOP2A down-regulation significantly decreased the protein levels of phosphor (p)-PI3K, p-Akt, and p-mTOR.

CONCLUSION

Our study demonstrates that TOP2A was overexpressed in GBC and associated with poor prognosis in GBC patients. TOP2A promotes GBC cell proliferation, migration, invasion, EMT process, and tumor growth through activating PI3K/Akt/mTOR signaling pathway, and may serve as a novel prognostic biomarker and therapeutic target for GBC.

The adenosine pathway in immuno-oncology

Cancer immunotherapy based on immune-checkpoint inhibition or adoptive cell therapy has revolutionized cancer care. Nevertheless, a large proportion of patients do not benefit from such treatments. Over the past decade, remarkable progress has been made in the development of 'next-generation' therapeutics in immuno-oncology, with inhibitors of extracellular adenosine (eADO) signalling constituting an expanding class of agents. Induced by tissue hypoxia, inflammation, tissue repair and specific oncogenic pathways, the adenosinergic axis is a broadly immunosuppressive pathway that regulates both innate and adaptive immune responses. Inhibition of eADO-generating enzymes and/or eADO receptors can promote antitumour immunity through multiple mechanisms, including enhancement of T cell and natural killer cell function, suppression of the pro-tumourigenic effects of myeloid cells and other immunoregulatory cells, and promotion of antigen presentation. With several clinical trials currently evaluating inhibitors of the eADO pathway in patients with cancer, we herein review the pathophysiological function of eADO with a focus on effects on antitumour immunity. We also discuss the treatment opportunities, potential limitations and biomarker-based strategies related to adenosine-targeted therapy in oncology.

The metastatic promoter DEPDC1B induces epithelial-mesenchymal transition and promotes prostate cancer cell proliferation via Rac1-PAK1 signaling

Metastasis is the major cause of prostate cancer (PCa)-related mortality. Epithelial-mesenchymal transition (EMT) is a vital characteristic feature that empowers cancer cells to adapt and survive at the beginning of metastasis. Therefore, it is essential to identify the regulatory mechanism of EMT in metastatic prostate cancer (mPCa) and to develop a novel therapy to block PCa metastasis. Here, we discovered a novel PCa metastasis oncogene, DEP domain containing 1B (DEPDC1B), which was positively correlated with the metastasis status, high Gleason score, advanced tumor stage, and poor prognosis. Functional assays revealed that DEPDC1B enhanced the migration, invasion, and proliferation of PCa cells in vitro and promoted tumor metastasis and growth in vivo. Mechanistic investigations clarified that DEPDC1B induced EMT and enhanced proliferation by binding to Rac1 and enhancing the Rac1-PAK1 pathway. This DEPDC1B-mediated oncogenic effect was reversed by a Rac1-GTP inhibitor or Rac1 knockdown. In conclusion, we discover that the DEPDC1B-Rac1-PAK1 signaling pathway may serve as a multipotent target for clinical intervention in mPCa.

EMT, MET, Plasticity, and Tumor Metastasis

Cancer cell identity and plasticity are required in transition states, such as epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET), in primary tumor initiation, progression, and metastasis. The functional roles of EMT, MET, and the partial state (referred to as pEMT) may vary based on the type of tumor, the state of dissemination, and the degree of metastatic colonization. Herein, we review EMT, MET, pEMT, and plasticity in the context of tumor metastasis.

True significance of N-acetylglucosaminyltransferases GnT-III, V and α1,6 fucosyltransferase in epithelial-mesenchymal transition and cancer

It is well known that numerous cancer-related changes occur in glycans that are attached to glycoproteins, glycolipids and proteoglycans on the cell surface and these changes in structure and the expression of the glycans are largely regulated by glycosyl-transferases, glycosidases, nucleotide sugars and their related genes. Such structural changes in glycans on cell surface proteins may accelerate the progression, invasion and metastasis of cancer cells. Among the over 200 known glycosyltransferases and related genes, β 1,6 N-acetylglucosaminyltransferase V (GnT-V) (the MGAT5 gene) and α 1,6 fucosyltransferase (FUT8) (the FUT8 gene) are representative enzymes in this respect because changes in glycans caused by these genes appear to be related to cancer metastasis and invasion in vitro as well as in vivo, and a number of reports on these genes in related to epithelial-mesenchymal transition (EMT) have also appeared. Another enzyme, one of the N-glycan branching enzymes, β1,4 N-acetylglucosaminyltransferase III (GnT-III) (the MGAT3 gene) has been reported to suppress EMT. However, there are intermediate states between EMT and mesenchymal-epithelial transition (MET) and some of these genes have been implicated in both EMT and MET and are also probably in an intermediate state. Therefore, it would be difficult to clearly define which specific glycosyltransferase is involved in EMT or MET or an intermediate state. The significance of EMT and N-glycan branching glycosyltransferases needs to be reconsidered and the inhibition of their corresponding genes would also be desirable in therapeutics. This review mainly focuses on GnT-III, GnT-V and FUT8, major players as N-glycan branching enzymes in cancer in relation to EMT programs, and also discusses the catalytic mechanisms of GnT-V and FUT8 whose crystal structures have now been obtained.

Interplay Between Ion Channels and the Wnt/β-Catenin Signaling Pathway in Cancers

Increasing evidence point out the important roles of ion channels in the physiopathology of cancers, so that these proteins are now considered as potential new therapeutic targets and biomarkers in this disease. Indeed, ion channels have been largely described to participate in many hallmarks of cancers such as migration, invasion, proliferation, angiogenesis, and resistance to apoptosis. At the molecular level, the development of cancers is characterised by alterations in transduction pathways that control cell behaviors. However, the interactions between ion channels and cancer-related signaling pathways are poorly understood so far. Nevertheless, a limited number of reports have recently addressed this important issue, especially regarding the interaction between ion channels and one of the main driving forces for cancer development: the Wnt/β-catenin signaling pathway. In this review, we propose to explore and discuss the current knowledge regarding the interplay between ion channels and the Wnt/β-catenin signaling pathway in cancers.

Role of Oral Bacteria in the Development of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is an invasive epithelial neoplasm that is influenced by various risk factors, with a low survival rate and an increasing death rate. In the past few years, with the verification of the close relationship between different types of cancers and the microbiome, research has focused on the compositional changes of oral bacteria and their role in OSCC. Generally, oral bacteria can participate in OSCC development by promoting cell proliferation and angiogenesis, influencing normal apoptosis, facilitating invasion and metastasis, and assisting cancer stem cells. The study findings on the association between oral bacteria and OSCC may provide new insight into methods for early diagnosis and treatment development.

Context Dependency of Epithelial-to-Mesenchymal Transition for Metastasis

Epithelial-to-mesenchymal transition (EMT) has been proposed to be important for metastatic dissemination. However, recent studies have challenged the requirement of EMT for metastasis. Here, we assessed in different models of primary skin squamous cell carcinomas (SCCs) whether EMT is associated with metastasis. The incidence of metastasis was much higher in SCCs presenting EMT compared to SCCs without EMT, supporting the notion that a certain degree of EMT is required to initiate the metastatic cascade in primary skin SCCs. Most circulating tumor cells presented EMT, whereas most lung metastasis did not present EMT, showing that mesenchymal-to-epithelial transition is important for metastatic colonization. In contrast, immunodeficient mice transplanted with SCCs, whether displaying EMT or not, presented metastasis. Altogether, our data demonstrate that the association of EMT and metastasis is model dependent, and metastasis of primary skin SCCs is associated with EMT.

Fusobacterium nucleatum Accelerates the Progression of Colitis-Associated Colorectal Cancer by Promoting EMT

Simple Summary

Colitis-associated cancer (CAC) are associated with the development and progression of colorectal cancer (CRC). And Fusobacterium nucleatum (F. nucleatum), a major pathogen involved in chronic periodontitis, may play an important role in CRC progression. Though the importance of F. nucleatum in CRC has attracted attention, its exact role and related mechanism in CAC progression remain unclear. We investigated the effects of F. nucleatum in both in vitro and in vivo colitis models induced with dextran sodium sulfate (DSS), a well-known colitis-inducing chemical, on the aggressiveness of CAC and its related mechanism. This study showed that F. nucleatum accelerates the progression of CAC cancer by promoting epithelial–mesenchymal transition (EMT). This study provides a novel mechanism involved F. nucleatum in the development of colitis-associated CRC.

Abstract

Recently, it has been reported that Fusobacterium nucleatum, a major pathogen involved in chronic periodontitis, may play an important role in colorectal cancer (CRC) progression. In addition, inflammatory bowel diseases such as ulcerative colitis and Crohn’s disease represent major predisposing conditions for the development of CRC, and this subtype of cancer is called colitis-associated cancer (CAC). Although the importance of F. nucleatum in CRC has attracted attention, its exact role and related mechanism in CAC progression remain unclear. In this study, we investigated the effects of F. nucleatum in experimental colitis induced with dextran sodium sulfate (DSS), which is a well-known colitis-inducing chemical, on the aggressiveness of CAC and its related mechanism in both in vitro and in vivo models. F. nucleatum synergistically increased the aggressiveness and epithelial–mesenchymal transition (EMT) characteristics of CRC cells that were treated with DSS compared to those in non-treated CRC cells. The role of F. nucleatum in CAC progression was further confirmed in mouse models, as F. nucleatum was found to significantly increase the malignancy of azoxymethane (AOM)/DSS-induced colon cancer. This promoting effect of F. nucleatum was based on activation of the EGFR signaling pathways, including protein kinase B (AKT) and extracellular signal-regulated kinase (ERK), and epidermal growth factor receptor (EGFR) inhibition significantly reduced the F. nucleatum-induced EMT alteration. In conclusion, F. nucleatum accelerates the progression of CAC by promoting EMT through the EGFR signaling pathway.

EpCAM cellular functions in adhesion and migration, and potential impact on invasion: A critical review

EpCAM has long been known as a cell surface protein highly expressed in carcinomas. It has since become one of the key cancer biomarkers. Despite its high fame, its actual role in cancer development is still controversial. Beyond a flurry of correlative studies, which point either to a positive or a negative link with tumour progression, there has been surprisingly few studies on the actual cellular mechanisms of EpCAM and on their functional consequences. Clearly, EpCAM plays multiple important roles, in cell proliferation as well as in cell adhesion and migration. The two latter functions, directly relevant for metastasis, are the focus of this review. We attempt here to bring together the available experimental data to build a global coherent view of EpCAM functions. We also include in this overview EpCAM2/Trop2, the close relative of EpCAM. At the core of EpCAM (and EpCAM2/Trop2) function stands the ability to repress contractility of the actomyosin cell cortex. This activity appears to involve direct inhibition by EpCAM of members of the novel PKC family and of a specific downstream PKD-Erk cascade. We will discuss how this activity can result in a variety of adhesive and migratory phenotypes, thus potentially explaining at least part of the apparent inconsistencies between different studies. The picture remains fragmented, and we will highlight some of the conflicting evidence and the many unsolved issues, starting with the controversy around its original description as a cell-cell adhesion molecule.

Epidermal growth factor-like domain multiple 6 (EGFL6) promotes the migration and invasion of gastric cancer cells by inducing epithelial-mesenchymal transition

Epidermal growth factor-like domain multiple 6 (EGFL6) is implicated in tumor growth, metastasis and angiogenesis, and its ectopic alteration has been detected in aggressive malignancies. However, the pathophysiologic roles and molecular mechanisms of EGFL6 in gastric cancer (GC) remain to be elucidated. In this study, we investigated EGFL6 expression in GC cell lines and tissues using western blotting and immunohistochemistry. We found that EGFL6 was elevated expression in GC cell lines and tissues. The high expression of EGFL6 significantly was correlated with histological grade, depth of invasion, lymph node involvement, distant metastasis and TNM stage in GC and predicted poorer prognosis, and it could act an independent prognostic factor for GC patients. EGFL6 enhanced the proliferation, migration and invasion of GC cells. In addition, we identified the possible molecular mechanisms of EGFL6-involved epithelial-mesenchymal transition (EMT). EGFL6 regulated EMT process and induced metastasis partly through FAK/PI3K/AKT/mTOR, Notch and MAPK signaling pathways. In conclusion, EGFL6 confers an oncogenic function in GC progression and may be proposed as a potential therapeutic target for GC.

Oncogenic roles of lncRNA BLACAT1 and its related mechanisms in human cancers

Long non-coding RNAs (lncRNAs) play indispensable roles in mediating regulation of epigenetics, and their dysregulation is strongly associated with the initiation and progression of human cancers. Recently, lncRNA bladder cancer-associated transcript 1 (BLACAT1) has been observed to exert oncogenic effects on cancers, including glioma, breast cancer, lung cancer, hepatocellular carcinoma, gastric cancer, colorectal cancer, ovarian cancer, cervical cancer and osteosarcoma. Additional mechanical analyses have uncovered that lncRNA BLACAT1 is positively correlated with tumor stage, lymph node metastasis and distant metastasis of primary tumors via involvement with various cellular activities, thus leading to poor overall survival and progression-free survival (PFS). In this review, we generalize the oncogenic roles of BLACAT1 in multiple human cancers through correlation with clinical implications and cellular activities. Moreover, we forecast its potential clinical application as a novel biomarker and a promising therapeutic target for cancers.

Association of tricellulin expression with poor colorectal cancer prognosis and metastasis

Tricellulin is a tight-junction transmembrane protein that regulates cell-cell interactions. Altered tricellulin expression could promote tumor cell invasions and metastasis in human cancers. The present study assessed tricellulin expression in colorectal cancer tissues for any association with clinicopathological features of colorectal cancer patients and then investigated the underlying molecular events using quantitative proteomic analysis and in vitro experiments. Tissue samples from 98 colorectal cancer patients and 15 volunteers were collected for immunohistochemistry. Colorectal cell lines were used to overexpress or knockdown tricellulin expression in various assays. The data revealed that upregulated tricellulin expression was associated with lymph node and distant metastases and poor prognosis, while tricellulin overexpression promoted colorectal cancer cell migration and invasion in vitro. In contrast, tricellulin knockdown had positive effects on the tumor cells. Furthermore, TMT-LC-MS/MS and bioinformatics analyses revealed that tricellulin was involved in EMT and reduction of apoptosis through the NF-κB signaling pathway. These findings highlight for the first time the significance of tricellulin in colorectal cancer development and progression. Further study may validate tricellulin as a novel biomarker and target for colorectal cancer.

Exosomal non‑coding RNAs: Novel biomarkers with emerging clinical applications in gastric cancer (Review)

Gastric cancer (GC) is one of the most common types of malignant tumor and it demonstrates high mortality rates. The majority of cases of GC are diagnosed at an advanced stage, which seriously endangers the health of the patient. Therefore, discovering a novel diagnostic method for GC is a current priority. Exosomes are 40 to 150-nm-diameter vesicles consisting of a lipid bilayer secreted by a variety of cells that exist in multiple different types of body fluids. Exosomes contain diverse types of active substances, including RNAs, proteins and lipids, and play important roles in tumor cell communication, metastasis and neovascularization, as well as tumor growth. Non-coding RNAs (ncRNAs) do not code proteins, and instead have roles in a variety of genetic mechanisms, such as regulating the structure, expression and stability of RNAs, and modulating the translation and function of proteins. In recent years, exosomal ncRNAs have become a novel focus in research. An increasing number of studies have demonstrated that exosomal ncRNAs can be used in the prediction and treatment of GC. The present review briefly discusses the role of exosomal ncRNAs as a potential biomarker, and summarizes important regulatory genes involved in the development and progression of GC.

miRNA-182 regulated MTSS1 inhibits proliferation and invasion in Glioma Cells

Human glioma is the most common malignant and fatal primary tumor in the central nervous system. Currently, the high incidence and low cure rate of glioma make it a considerable threat to human health. Thus, elucidating the molecular mechanisms of glioma development and progression has become a major focus to identify new and effective biomarkers and improve the comprehensive neurosurgical treatment of glioma from the basic research and clinical perspectives. In our present study, we aimed to investigate the expression pattern and biological function of Metastasis suppressor protein 1(MTSS1) in glioma and to further explore whether miRNAs were involved in the deregulation of MTSS1. By overexpressing MTSS1 in highly malignant human glioma cells, we discovered a role for MTSS1 in suppressing the proliferation and invasion of glioma cells, and we showed that MTSS1 participated in transforming growth factor-beta 1 (TGF-β1) -induced epithelial-mesenchymal transition (EMT) in glioma cells. Biochemical analyses suggested that miR-182 may target MTSS1 and that miR-182 expression is negatively correlated with MTSS1 expression in glioma tissues. This finding was further confirmed by luciferase reporter experiments. Furthermore, a miR-182 inhibitor induced glioma cell proliferation and invasion by increasing MTSS1 expression. In conclusion, we believed that miR-182 modulates glioma cell migration and invasion by targeting the MTSS1 and suggested that miR-182 was a potential therapeutic target for gliomas.

circKRT7-miR-29a-3p-COL1A1 Axis Promotes Ovarian Cancer Cell Progression

Background

Circular RNA (circRNA) has emerged as an important regulator in the progression of human diseases. However, the role of circRNAs in ovarian cancer remains largely unknown.

Materials and Methods

DNA sequencing and PCR were used to identify the existence and expression of circKRT7. The targeting relationship between circKRT7/miR-29a-3p and miR-29a-3p/COL1A1 was verified by fluorescence reporter assay. In vitro, colony formation, transwell and wound healing assay were used to detect the effects of circKRT7 and miR-29a-3p on the proliferation, migration and invasion ability of ovarian cancer cells. In vivo, xenograft tumor model was performed to validate the role of circKRT7 and miR-29a-3p in tumor growth.

Results

We found that circKRT7 can promote the proliferation and metastasis of ovarian cancer cells by absorbing miR-29a-3p, which leads to the up-regulation of COL1A1. In vitro, knock-down of circKRT7 can inhibit the migration and invasion of ovarian cancer cells. This effect of circKRT7 is achieved by adsorbing miR-29a-3p and subsequently COL1A1 release. In vivo experiments, the reduction of circKRT7 expression can also slow tumor growth, and this inhibition was partly counteracted after miR-29a-3p repression.

Conclusion

Overall, circKRT7 promotes EMT-related cell progression by absorbing miR-29a-3p in ovarian cancer. This suggests the crucial role of circular RNA in the malignant evolution in cancer.

NFATc Acts as a Non-Canonical Phenotypic Stability Factor for a Hybrid Epithelial/Mesenchymal Phenotype

Metastasis remains the cause of over 90% of cancer-related deaths. Cells undergoing metastasis use phenotypic plasticity to adapt to their changing environmental conditions and avoid therapy and immune response. Reversible transitions between epithelial and mesenchymal phenotypes – epithelial–mesenchymal transition (EMT) and its reverse mesenchymal–epithelial transition (MET) – form a key axis of phenotypic plasticity during metastasis and therapy resistance. Recent studies have shown that the cells undergoing EMT/MET can attain one or more hybrid epithelial/mesenchymal (E/M) phenotypes, the process of which is termed as partial EMT/MET. Cells in hybrid E/M phenotype(s) can be more aggressive than those in either epithelial or mesenchymal state. Thus, it is crucial to identify the factors and regulatory networks enabling such hybrid E/M phenotypes. Here, employing an integrated computational-experimental approach, we show that the transcription factor nuclear factor of activated T-cell (NFATc) can inhibit the process of complete EMT, thus stabilizing the hybrid E/M phenotype. It increases the range of parameters enabling the existence of a hybrid E/M phenotype, thus behaving as a phenotypic stability factor (PSF). However, unlike previously identified PSFs, it does not increase the mean residence time of the cells in hybrid E/M phenotypes, as shown by stochastic simulations; rather it enables the co-existence of epithelial, mesenchymal and hybrid E/M phenotypes and transitions among them. Clinical data suggests the effect of NFATc on patient survival in a tissue-specific or context-dependent manner. Together, our results indicate that NFATc behaves as a non-canonical PSF for a hybrid E/M phenotype.

Hispidulin: A promising flavonoid with diverse anti-cancer properties

In recent years, natural products have increasingly attracted more attention because of their potential anticancer activity and low intrinsic toxicity. Hispidulin is a natural flavonoid with a wide range of biological activities, including anti-inflammatory, antifungal, antiplatelet, anticonvulsant, anti-osteoporotic, and notably anticancer activities. Numerous in vivo and in vitro studies have shown that hispidulin, as a potential anticancer drug, affects cell proliferation, apoptosis, cell cycle, angiogenesis, and metastasis. Moreover, hispidulin exhibits synergistic anti-tumor effects when combined with some common clinical anticancer drugs (e.g., gemcitabine, 5-fluoroucil, sunitinib, temozolomide, and TRAIL). The combination of hispidulin and chemotherapeutic drugs reduces the efflux of chemotherapeutic drugs, enhances the chemosensitivity of cancer cells, and reverses drug resistance. Herein, we outlined the anticancer effects of hispidulin in various cancers and its intracellular molecular targets and related mechanisms of its anticancer activity. Based on the available literature, it can be established that hispidulin has significant potential to become an important complementary medicine for cancer prevention and treatment. However, more in-depth in vitro and in vivo studies should be conducted to support its translation from bench to bedside.

FBLN5 is targeted by microRNA‑27a‑3p and suppresses tumorigenesis and progression in high‑grade serous ovarian carcinoma

High-grade serous ovarian carcinoma (HGSOC) is one of the most lethal gynecological malignancies; however, the precise molecular mechanisms have not been fully characterized. Fibulin-5 (FBLN-5) is an extracellular matrix (ECM) glycoprotein, and plays a crucial role in maintaining the stability of ECM structures, regulating cell proliferation and tumorigenesis. In the present study, the expression of FBLN-5, as determined by western blot analysis and immunohistochemistry, was significantly increased in normal fallopian tube (FT) samples compared with that in HGSOC samples, and decreased FBLN5 expression was associated with unfavorable prognosis of HGSOC. Functional characterization revealed that FBLN5 overexpression significantly inhibited migration, invasion and proliferation abilities of ovarian cancer cells in vitro. Furthermore, micro (mi)RNA-27a-3p (miR-27a-3p) was revealed to be increased in HGSOC, and dual-luciferase reporter assay indicated that miR-27a-3p was functioned as a negative regulator of FBLN5 by directly binding with its 3′-untranslated region. Collectively, FBLN5 expression was associated with prognosis, proliferation, and metastasis in HGSOC. We hypothesized that FBLN5 was targeted by miR-27a-3p and may serve as a biomarker and provide a new therapeutic approach for the treatment of HGSOC.

ALDH5A1 acts as a tumour promoter and has a prognostic impact in papillary thyroid carcinoma

Thyroid cancer is the most common endocrine carcinoma, with papillary thyroid carcinoma (PTC) accounting for 80%-90% of thyroid cancers. Accumulating studies reported that mitochondria plays an important role in the regulation of cell proliferation. ALDH5A1, may function as an oncogene or tumour suppressor in various human cancers, and the role of ALDH5A1 in PTC is still unclear. The aim of this study was to investigate the clinical significance of ALDH5A1 expression and its functions in PTC. In this present study, we studied ALDH5A1 expression on primary papillary thyroid carcinoma (PTC) in The Cancer Genome Atlas (TCGA) database. Results showed that the levels of ALDH5A1 were found positively correlated with tumour stage, metastasis, lymph node stage, and higher levels of ALDH5A1 demonstrated poor disease-free survival (DFS). Immunohistochemistry (IHC) revealed that significantly higher expression of ALDH5A1 was found in PTC tissues. On the other hand, knockdown of ALDH5A1 significantly inhibited PTC cell proliferation, migration and invasion detection found the migration and invasion of cells also were hindered when ALDH5A1 level was reduced. The knockdown of ALDH5A1 inhibited the expression of Vimentin and promoted the expression of E-cadherin. In brief, knockdown of ALDH5A1may act as a novel molecular target for the prevention and treatment of PTC. SIGNIFICANCE OF THE STUDY: The present study focused on the role and the potential mechanism of ALDH5A1 in papillary thyroid carcinoma. We demonstrated that reduced expression of ALDH5A1 might inhibit the progression of TC by inhibiting cell proliferation, migration and invasion and reversing epithelial-mesenchymal transition (EMT). The findings ensured the interaction relation between ALDH5A1 and EMT in PTC, providing a novel biological marker for PTC and enriching the potential strategies for TC treatment.

Implications of telomerase reverse transcriptase in tumor metastasis

Metastasis is the main culprit of the great majority of cancerrelated deaths. However, the complicated process of the invasion-metastasis cascade remains the least understood aspect of cancer biology. Telomerase plays a pivotal role in bypassing cellular senescence and sustaining the cancer progression by maintaining telomere homeostasis and genomic integrity. Telomerase reverse transcriptase (TERT) exerts a series of fundamental functions that are independent of its enzymatic cellular activity, including proliferation, inflammation, epithelia-mesenchymal transition (EMT), angiogenesis, DNA repair, and gene expression. Accumulating evidence indicates that TERT may facilitate most steps of the invasion-metastasis cascade. In this review, we summarize important advances that have revealed some of the mechanisms by which TERT facilitates tumor metastasis, providing an update on the non-canonical functions of telomerase beyond telomere maintaining. [BMB Reports 2020; 53(9): 458-465].

Metastasis-Specific Gene Expression in Autochthonous and Allograft Mouse Mammary Tumor Models: Stratification and Identification of Targetable Signatures

Breast cancer metastasis is a leading cause of cancer-related death of women in the United States. A hurdle in advancing metastasis-targeted intervention is the phenotypic heterogeneity between primary and secondary lesions. To identify metastasis-specific gene expression profiles we performed RNA-sequencing of breast cancer mouse models; analyzing metastases from models of various drivers and routes. We contrasted the models and identified common, targetable signatures. Allograft models exhibited more mesenchymal-like gene expression than genetically engineered mouse models (GEMM), and primary culturing of GEMM-derived metastatic tissue induced mesenchymal-like gene expression. In addition, metastasis-specific transcriptomes differed between tail vein and orthotopic injection of the same cell line. Gene expression common to models of spontaneous metastasis included sildenafil response and nicotine degradation pathways. Strikingly, in vivo sildenafil treatment significantly reduced metastasis by 54%, while nicotine significantly increased metastasis by 46%. These data suggest that (i) actionable metastasis-specific pathways can be readily identified, (ii) already available drugs may have great potential to alleviate metastatic incidence, and (iii) metastasis may be influenced greatly by lifestyle choices such as the choice to consume nicotine products. In summary, while mouse models of breast cancer metastasis vary in ways that must not be ignored, there are shared features that can be identified and potentially targeted therapeutically. IMPLICATIONS: The data we present here exposes critical variances between preclinical models of metastatic breast cancer and identifies targetable pathways integral to metastatic spread. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/molcanres/18/9/1278/F1.large.jpg.

Cholangiocarcinoma 2020: the next horizon in mechanisms and management

Cholangiocarcinoma (CCA) includes a cluster of highly heterogeneous biliary malignant tumours that can arise at any point of the biliary tree. Their incidence is increasing globally, currently accounting for ~15% of all primary liver cancers and ~3% of gastrointestinal malignancies. The silent presentation of these tumours combined with their highly aggressive nature and refractoriness to chemotherapy contribute to their alarming mortality, representing ~2% of all cancer-related deaths worldwide yearly. The current diagnosis of CCA by non-invasive approaches is not accurate enough, and histological confirmation is necessary. Furthermore, the high heterogeneity of CCAs at the genomic, epigenetic and molecular levels severely compromises the efficacy of the available therapies. In the past decade, increasing efforts have been made to understand the complexity of these tumours and to develop new diagnostic tools and therapies that might help to improve patient outcomes. In this expert Consensus Statement, which is endorsed by the European Network for the Study of Cholangiocarcinoma, we aim to summarize and critically discuss the latest advances in CCA, mostly focusing on classification, cells of origin, genetic and epigenetic abnormalities, molecular alterations, biomarker discovery and treatments. Furthermore, the horizon of CCA for the next decade from 2020 onwards is highlighted.

Metabolic rewiring in the promotion of cancer metastasis: mechanisms and therapeutic implications

Tumor metastasis is the major cause of mortality from cancer. Metabolic rewiring and the metastatic cascade are highly intertwined, co-operating to promote multiple steps of cancer metastasis. Metabolites generated by cancer cells influence the metastatic cascade, encompassing epithelial-mesenchymal transition (EMT), survival of cancer cells in circulation, and metastatic colonization at distant sites. A variety of molecular mechanisms underlie the prometastatic effect of tumor-derived metabolites, such as epigenetic deregulation, induction of matrix metalloproteinases (MMPs), promotion of cancer stemness, and alleviation of oxidative stress. Conversely, metastatic signaling regulates expression and activity of rate-limiting metabolic enzymes to generate prometastatic metabolites thereby reinforcing the metastasis cascade. Understanding the complex interplay between metabolism and metastasis could unravel novel molecular targets, whose intervention could lead to improvements in the treatment of cancer. In this review, we summarized the recent discoveries involving metabolism and tumor metastasis, and emphasized the promising molecular targets, with an update on the development of small molecule or biologic inhibitors against these aberrant situations in cancer.

Expression and function of epithelial cell adhesion molecule EpCAM: where are we after 40 years?

EpCAM (epithelial cell adhesion molecule) was discovered four decades ago as a tumor antigen on colorectal carcinomas. Owing to its frequent and high expression on carcinomas and their metastases, EpCAM serves as a prognostic marker, a therapeutic target, and an anchor molecule on circulating and disseminated tumor cells (CTCs/DTCs), which are considered the major source for metastatic cancer cells. Today, EpCAM is reckoned as a multi-functional transmembrane protein involved in the regulation of cell adhesion, proliferation, migration, stemness, and epithelial-to-mesenchymal transition (EMT) of carcinoma cells. To fulfill these functions, EpCAM is instrumental in intra- and intercellular signaling as a full-length molecule and following regulated intramembrane proteolysis, generating functionally active extra- and intracellular fragments. Intact EpCAM and its proteolytic fragments interact with claudins, CD44, E-cadherin, epidermal growth factor receptor (EGFR), and intracellular signaling components of the WNT and Ras/Raf pathways, respectively. This plethora of functions contributes to shaping intratumor heterogeneity and partial EMT, which are major determinants of the clinical outcome of carcinoma patients. EpCAM represents a marker for the epithelial status of primary and systemic tumor cells and emerges as a measure for the metastatic capacity of CTCs. Consequentially, EpCAM has reclaimed potential as a prognostic marker and target on primary and systemic tumor cells.

ABHD4-dependent developmental anoikis safeguards the embryonic brain

A specialized neurogenic niche along the ventricles accumulates millions of progenitor cells in the developing brain. After mitosis, fate-committed daughter cells delaminate from this germinative zone. Considering the high number of cell divisions and delaminations taking place during embryonic development, brain malformations caused by ectopic proliferation of misplaced progenitor cells are relatively rare. Here, we report that a process we term developmental anoikis distinguishes the pathological detachment of progenitor cells from the normal delamination of daughter neuroblasts in the developing mouse neocortex. We identify the endocannabinoid-metabolizing enzyme abhydrolase domain containing 4 (ABHD4) as an essential mediator for the elimination of pathologically detached cells. Consequently, rapid ABHD4 downregulation is necessary for delaminated daughter neuroblasts to escape from anoikis. Moreover, ABHD4 is required for fetal alcohol-induced apoptosis, but not for the well-established form of developmentally controlled programmed cell death. These results suggest that ABHD4-mediated developmental anoikis specifically protects the embryonic brain from the consequences of sporadic delamination errors and teratogenic insults.

Combination of DN604 with gemcitabine led to cell apoptosis and cell motility inhibition via p38 MAPK signaling pathway in NSCLC

Non-small-cell lung cancer (NSCLC) is the most common cancer in the world, which is still treated with Pt(II) agents as first-line drugs. As a traditional anticancer agent, gemcitabine is usually used in the combination treatment of various solid tumors with other drugs. Here, we investigate the combinatory application of gemcitabine with a Pt(II) agent (DN604, reported previously in our former research) in the treatment of NSCLC. In vitro biological assays suggested that DN604-gemcitabine treatment can effectively induce cell apoptosis and suppress cell motility, showing better anti-tumor effect than the single drug treatment or the combined treatment of cisplatin and gemcitabine. More importantly, investigation on the mechanism of the combined treatment proved that such combined treatment can suppress cell autophagy to inhibit cell motility via the activation of p38 MAPK signaling pathway. In vivo studies indicated that combination of DN604 with gemcitabine significantly inhibited the growth of tumor with nearly no influence on the normal organs and weight of mice. Our study widened the application scope of Pt(II) agents combined with gemcitabine for NSCLC treatment.

Mechanism of transmembrane and coiled-coil domain 1 in the regulation of proliferation and migration of A549 cells

Bioinformatics analyses have shown that transmembrane and coiled-coil domain 1 (TMCO1) may be associated with lung adenocarcinoma. However, to the best of our knowledge, no current research has determined whether TMCO1 is involved in the development of lung adenocarcinoma. The present study aimed to identify the association between TMCO1 and lung adenocarcinoma. The present study demonstrated that the positive immunohistochemical staining of TMCO1 in lung adenocarcinoma tissues was significantly higher compared with paracarcinoma tissues. Additionally, knockdown of TMCO1 was demonstrated to downregulate B-cell lymphoma-2 protein expression levels and upregulate cysteinyl aspartate specific proteinase (caspase)-3 and caspase-9 protein expression levels in A549 cells. These changes resulted in decreased apoptosis of A549 cells uponTMCO1 downregulation. In addition, knockdown of TMCO1 decreased matrix metalloproteinase (MMP)-2 and MMP-9 expression levels. The expression of N-cadherin and vimentin also decreased. By contrast, the expression levels of E-cadherin protein increased. Knockdown of TMCO1 resulted in the inhibition of A549 cell migration. The results of the present study demonstrated that TMCO1 was associated with lung adenocarcinoma and that inhibition of TMCO1 expression levels negatively regulated the apoptosis and migration of lung adenocarcinoma cells. Therefore, the present study suggests the potential for TMCO1 to be used in the clinical treatment of lung adenocarcinoma.

Proteoglycans in the Pathogenesis of Hormone-Dependent Cancers: Mediators and Effectors

Hormone-dependent cancers exhibit high morbidity and mortality. In spite of advances in therapy, the treatment of hormone-dependent cancers remains an unmet health need. The tumor microenvironment (TME) exhibits unique characteristics that differ among various tumor types. It is composed of cancerous, non-cancerous, stromal, and immune cells that are surrounded and supported by components of the extracellular matrix (ECM). Therefore, the interactions among cancer cells, stromal cells, and components of the ECM determine cancer progression and response to therapy. Proteoglycans (PGs), hybrid molecules consisting of a protein core to which sulfated glycosaminoglycan chains are bound, are significant components of the ECM that are implicated in all phases of tumorigenesis. These molecules, secreted by both the stroma and cancer cells, are crucial signaling mediators that modulate the vital cellular pathways implicated in gene expression, phenotypic versatility, and response to therapy in specific tumor types. A plethora of deregulated signaling pathways contributes to the growth, dissemination, and angiogenesis of hormone-dependent cancers. Specific inputs from the endocrine and immune systems are some of the characteristics of hormone-dependent cancer pathogenesis. Importantly, the mechanisms involved in various aspects of cancer progression are executed in the ECM niche of the TME, and the PG components crucially mediate these processes. Here, we comprehensively discuss the mechanisms through which PGs affect the multifaceted aspects of hormone-dependent cancer development and progression, including cancer metastasis, angiogenesis, immunobiology, autophagy, and response to therapy.

Endosulfan triggers epithelial-mesenchymal transition via PTP4A3-mediated TGF-β signaling pathway in prostate cancer cells

Endosulfan is a persistent organochlorine pesticide that bioaccumulates in human body through the food chain and thus represents a potential risk to public health. Despite epidemiological studies, the molecular mechanisms underlying the carcinogenic effects of endosulfan in the prostate remain poorly understood. In this study, we investigated the effect of endosulfan on epithelial-mesenchymal transition (EMT) in human prostate cancer PC3 and DU145 cells. Endosulfan induced alterations of EMT biomarkers, reflecting repression of E-cadherin expression and induction of fibronectin, snail2, ZEB2, Twist1 and Vimentin. The expression of Protein-tyrosine Phosphatase 4A3 (PTP4A3) at mRNA and protein levels was upregulated by endosulfan. PTP4A3 inhibitor reversed the changes of EMT biomarkers, PTP4A3 and p-Smad2/Smad2, but did not affect the upregulation of Cleaved-Notch1 and Jagged1 in endosulfan-exposed cells. Endosulfan promoted cell migration and invasion, which were rescued by specific inhibitors for PTP4A3, TGF-β signaling and Notch signaling, respectively. These findings suggest that endosulfan promoted cell migration and invasion with the induction of EMT through PTP4A3-mediated TGF-β signaling pathway in prostate cancer cells.

Leukotrienes in Tumor-Associated Inflammation

Leukotrienes are biologically active eicosanoid lipid mediators that originate from oxidative metabolism of arachidonic acid. Biosynthesis of leukotrienes involves a set of soluble and membrane-bound enzymes that constitute a machinery complex primarily expressed by cells of myeloid origin. Leukotrienes and their synthetic enzymes are critical immune modulators for leukocyte migration. Increased concentrations of leukotrienes are implicated in a number of inflammatory disorders. More recent work indicates that leukotrienes may also interact with a variety of tissue cells, contributing to the low-grade inflammation of cardiovascular, neurodegenerative, and metabolic conditions, as well as that of cancer. Leukotriene signaling contributes to the active tumor microenvironment, promoting tumor growth and resistance to immunotherapy. This review summarizes recent insights into the intricate roles of leukotrienes in promoting tumor growth and metastasis through shaping the tumor microenvironment. The emerging possibilities for pharmacological targeting of leukotriene signaling in tumor metastasis are considered.

The glutathione peroxidase 8 (GPX8)/IL-6/STAT3 axis is essential in maintaining an aggressive breast cancer phenotype

One of the emerging hallmarks of cancer illustrates the importance of metabolic reprogramming, necessary to synthesize the building blocks required to fulfill the high demands of rapidly proliferating cells. However, the proliferation-independent instructive role of metabolic enzymes in tumor plasticity is still unclear. Here, we provide evidence that glutathione peroxidase 8 (GPX8), a poorly characterized enzyme that resides in the endoplasmic reticulum, is an essential regulator of tumor aggressiveness. We found that GPX8 expression was induced by the epithelial-mesenchymal transition (EMT) program. Moreover, in breast cancer patients, GPX8 expression significantly correlated with known mesenchymal markers and poor prognosis. Strikingly, GPX8 knockout in mesenchymal-like cells (MDA-MB-231) resulted in an epithelial-like morphology, down-regulation of EMT characteristics, and loss of cancer stemness features. In addition, GPX8 knockout significantly delayed tumor initiation and decreased its growth rate in mice. We found that these GPX8 loss-dependent phenotypes were accompanied by the repression of crucial autocrine factors, in particular, interleukin-6 (IL-6). In these cells, IL-6 bound to the soluble receptor (sIL6R), stimulating the JAK/STAT3 signaling pathway by IL-6 trans-signaling mechanisms, so promoting cancer aggressiveness. We observed that in GPX8 knockout cells, this signaling mechanism was impaired as sIL6R failed to activate the JAK/STAT3 signaling pathway. Altogether, we present the GPX8/IL-6/STAT3 axis as a metabolic-inflammatory pathway that acts as a robust regulator of cancer cell aggressiveness.

Histone deacetylase inhibitors promote epithelial-mesenchymal transition in Hepatocellular Carcinoma via AMPK-FOXO1-ULK1 signaling axis-mediated autophagy

Hepatocellular carcinoma (HCC) is the third most frequent cause of cancer-related deaths globally because of high metastasis and recurrence rates. Elucidating the molecular mechanisms of HCC recurrence and metastasis and developing effective targeted therapies are expected to improve patient survival. The promising anti-cancer agents for the treatment of hematological malignancies, histone deacetylase inhibitors (HDIs), have limited effects against epithelial cell-derived cancers, including HCC, the mechanisms involved have not been elucidated. Herein, we studied the molecular mechanisms underlying HDI-induced epithelial-mesenchymal transition (EMT) involving FOXO1-mediated autophagy. Methods: The biological functions of HDIs in combination with autophagy inhibitors were examined both in vitro and in vivo. Cell autophagy was assessed using the generation of mRFP-GFP-LC3-expressing cells and fluorescent LC3 puncta analysis, Western blotting, and electron microscopy. An orthotopic hepatoma model was established in mice for the in vivo experiments. Results: Our study provided novel mechanistic insights into HDI-induced EMT mediated by the autophagy AMPK-FOXO1-ULK1-Snail signaling axis. We demonstrated that autophagy served as a pro-metastasis mechanism in HDI-treated hepatoma cells. HDIs induced autophagy via a FOXO1-dependent pathway, and FOXO1 inhibition promoted HDI-mediated apoptosis in hepatoma cells. Thus, our findings provided novel insights into the molecular mechanisms underlying HDI-induced EMT involving FOXO1-mediated autophagy and demonstrated that a FOXO1 inhibitor exerted a synergistic effect with an HDI to inhibit cell growth and metastasis in vitro and in vivo. Conclusion: We demonstrated that HDIs triggers FOXO1-dependent autophagy, which ultimately promotes EMT, limiting the clinical outcome of HDI-based therapies. Our study suggests that the combination of an HDI and a FOXO1 inhibitor is an effective therapeutic strategy for the treatment of HCC.

Relevance Function of Linc-ROR in the Pathogenesis of Cancer

Long non-coding RNAs (lncRNAs) are the key components of non-coding RNAs (ncRNAs) with a length of 200 nucleotides. They are transcribed from the so-called “dark matter” of the genome. Increasing evidence have shown that lncRNAs play an important role in the pathophysiology of human diseases, particularly in the development and progression of tumors. Linc-ROR, as a new intergenic non-protein coding RNA, has been considered to be a pivotal regulatory factor that affects the occurrence and development of human tumors, including breast cancer (BC), colorectal cancer (CRC), pancreatic cancer (PC), hepatocellular carcinoma (HCC), and so on. Dysregulation of Linc-ROR has been closely related to advanced clinicopathological factors predicting a poor prognosis. Because linc-ROR can regulate cell proliferation, apoptosis, migration, and invasion, it can thus be used as a potential biomarker for patients with tumors and has potential clinical significance as a therapeutic target. This article reviewed the role of linc-ROR in the development of tumors, its related molecular mechanisms, and clinical values.

CRMP2 is a therapeutic target that suppresses the aggressiveness of breast cancer cells by stabilizing RECK

Metastatic breast cancer is characterized by high mortality and limited therapeutic target. During tumor metastasis, cytoskeletal reorganization is one of the key steps in the migration and invasion of breast cancer cells. Collapsin response mediator protein 2 (CRMP2) is a cytosolic phosphoprotein that plays an important role in regulating cytoskeletal dynamics. Previous researches have reported that altered CRMP2 expression is associated with breast cancer progression, but the underlying mechanism remains poorly understood. Here, we show that CRMP2 expression is reduced in various subtypes of breast cancers and negatively correlated with lymphatic metastasis. Overexpression of CRMP2 significantly inhibits invasion and stemness in breast cancer cells, while downregulation of CRMP2 promotes cell invasion, which is not required for tubulin polymerization. Mechanistic studies demonstrate that CRMP2 interacts with RECK, prevents RECK degradation, which, in turn, blocks NF-κB and Wnt signaling pathways. Furthermore, we find that phosphorylation of CRMP2 at T514 and S522 remarkably abolishes its functions to bind with RECK and to inhibit cell invasion. Pharmacologic rescue of CRMP2 expression suppressed breast cancer metastasis in vitro and in vivo and stimulated a synergetic effect with FN-1501 that induces CRMP2 dephosphorylation. Collectively, this study highlights the potential of CRMP2 as a therapeutic target in breast cancer metastasis and reveals a distinct mechanism of CRMP2.

Epithelial-Mesenchymal Transition and Metabolic Switching in Cancer: Lessons From Somatic Cell Reprogramming

Epithelial-mesenchymal transition (EMT) and its critical roles during cancer progression have long been recognized and extensively reviewed. Recent studies on the generation of induced pluripotent stem cells (iPSCs) have established the connections among EMT, energy metabolism, DNA methylation, and histone modification. Since energy metabolism, DNA methylation, and histone modification are important for cancer development and there are common characteristics between cancer cells and stem cells, it is reasonable to identify mechanisms that have been established during both reprogramming and cancer progression. In the current review, we start from a brief review on EMT and related processes during cancer progression, and then switch to the EMT during somatic cell reprogramming. We summarize the connection between EMT and metabolic switch during reprogramming, and further review the involvements of DNA methylation and cell proliferation. The connections between EMT and mesenchymal-epithelial transition (MET) and cellular aspects including DNA methylation, histone modification and energy metabolism may provide potential new targets for cancer diagnosis and treatment.

Clinical Impact of the Epithelial-Mesenchymal Transition in Lung Cancer as a Biomarker Assisting in Therapeutic Decisions

Lung cancer is one of the most common solid cancers and represents the leading cause of cancer death worldwide. Over the last decade, research on the epithelial-mesenchymal transition (EMT) in lung cancer has gained increasing attention. Here, we review clinical and histological features of non-small-cell lung cancer associated with EMT. We then aimed to establish potential clinical implications of EMT in current therapeutic options, including surgery, radiation, targeted therapy against oncogenic drivers, and immunotherapy.

FYN promotes gastric cancer metastasis by activating STAT3-mediated epithelial-mesenchymal transition

Gastric cancer is one of the most lethal cancers worldwide. FYN, a gene that is differentially expressed in gastric cancer, is considered a critical metastasis regulator in several solid tumors, but its role in gastric cancer is still unclear. This study aimed to evaluate the role of FYN and test whether FYN promotes migration and invasion of gastric cancer cells in vitro and in vivo via STAT3 signaling. FYN was overexpressed in gastric cancer and positively correlated with metastasis. FYN knockdown significantly decreased cancer cell migration and invasion, whereas FYN overexpression increased cancer migration and invasion. Genetic inhibition of FYN decreased the number of metastatic lung nodules in vivo. Several epithelial-mesenchymal transition markers were positively correlated with FYN expression, indicative of FYN involvement in this transition. Furthermore, gene set enrichment analysis of a Cancer Genome Atlas dataset revealed that the STAT3 signaling pathway was positively correlated with FYN expression. STAT3 inhibition reversed the FYN-mediated epithelial-mesenchymal transition and suppressed metastasis. In conclusion, FYN promotes gastric cancer metastasis possibly by activating STAT3-mediated epithelial mesenchymal transition and may be a novel therapeutic target for gastric cancer.

Alantolactone inhibits proliferation, metastasis and promotes apoptosis of human osteosarcoma cells by suppressing Wnt/β-catenin and MAPKs signaling pathways

Although there are many therapeutic strategies such as surgery and chemotherapy, the prognosis of osteosarcoma (OS) is still far from being satisfactory. It is urgent to develop more effective, tolerable and safe drugs for the treatment of OS. In the present study, we investigated the anti-OS activity of Alantolactone (ALT), a natural eucalyptone sesquiterpene lactone mainly exists in Inula helenium, and probed the possible mechanism involved. We demonstrated that ALT significantly inhibited cell proliferation of various human OS cell lines while had relative lower cytotoxicity against normal cells. Then, we validated that ALT reduced migration, decreased invasion possibly through reversing epithelial mesenchymal transition (EMT) process and suppressing Matrix metalloproteinases (MMPs). Moreover, we confirmed that ALT promoted apoptosis and arrested cell cycle at G2/M phase of human OS cells in vitro. In addition, we confirmed that ALT restrained tumor growth and metastasis of OS 143 cells in a xenograft model in vivo. Mechanistically, ALT inhibited the activity of Wnt/β-catenin and p38, ERK1/2 and JNK Mitogen Activated Protein Kinases (MAPKs) signal pathway. Notably, the combination of ALT and Wnt/β-catenin inhibitor, as well as the combination of ALT and MAPKs inhibitors resulted in a synergistically effect on inhibiting the proliferation, migration and invasion of OS cells. Collectively, our results validate the ALT may inhibit proliferation, metastasis and promotes apoptosis of human OS cells possibly through suppressing Wnt/β-Catenin and MAPKs signaling pathways.

Eco-oncology: Applying ecological principles to understand and manage cancer

Cancer is a disease of single cells that expresses itself at the population level. The striking similarities between initiation and growth of tumors and dynamics of biological populations, and between metastasis and ecological invasion and community dynamics suggest that oncology can benefit from an ecological perspective to improve our understanding of cancer biology. Tumors can be viewed as complex, adaptive, and evolving systems as they are spatially and temporally heterogeneous, continually interacting with each other and with the microenvironment and evolving to increase the fitness of the cancer cells. We argue that an eco-evolutionary perspective is essential to understand cancer biology better. Furthermore, we suggest that ecologically informed therapeutic approaches that combine standard of care treatments with strategies aimed at decreasing the evolutionary potential and fitness of neoplastic cells, such as disrupting cell-to-cell communication and cooperation, and preventing successful colonization of distant organs by migrating cancer cells, may be effective in managing cancer as a chronic condition.

Understanding the Principles of Pattern Formation Driven by Notch Signaling by Integrating Experiments and Theoretical Models

Notch signaling is an evolutionary conserved cell-cell communication pathway. Besides regulating cell-fate decisions at an individual cell level, Notch signaling coordinates the emergent spatiotemporal patterning in a tissue through ligand-receptor interactions among transmembrane molecules of neighboring cells, as seen in embryonic development, angiogenesis, or wound healing. Due to its ubiquitous nature, Notch signaling is also implicated in several aspects of cancer progression, including tumor angiogenesis, stemness of cancer cells and cellular invasion. Here, we review experimental and computational models that help understand the operating principles of cell patterning driven by Notch signaling. First, we discuss the basic mechanisms of spatial patterning via canonical lateral inhibition and lateral induction mechanisms, including examples from angiogenesis, inner ear development and cancer metastasis. Next, we analyze additional layers of complexity in the Notch pathway, including the effect of varying cell sizes and shapes, ligand-receptor binding within the same cell, variable binding affinity of different ligand/receptor subtypes, and filopodia. Finally, we discuss some recent evidence of mechanosensitivity in the Notch pathway in driving collective epithelial cell migration and cardiovascular morphogenesis.

Targeting deubiquitinating enzyme USP26 by microRNA-203 regulates Snail1's pro-metastatic functions in esophageal cancer

Background

Esophageal cancer is one of the most common cancers worldwide with poor prognosis and high mortality. The transcription factor SNAI1, encoding Snail1, is important for metastatic progression in esophageal cancer whereas the microRNA (miRNA)-203 has been shown to function as an inhibitor of metastasis in EC. The Snail1 protein is stabilized in EC partially by the deubiquitinating enzyme USP26; however, how USP26 is regulated is not completely known.

Methods

Expression of SNAI1 and USP26 messenger RNA (mRNA) and miR-203 was performed in datasets within The Cancer Genome Atlas and Gene Expression Omnibus, respectively. Expression of Snail1 and USP26 protein and miR-203 was determined in the normal esophageal cell line HET-1A and EC cell lines Kyse150 and TE-1 using western blot and quantitative polymerase chain reaction, respectively. TargetScan was used for in situ prediction of miR-203 targets and in vitro heterologous reporter assays using the wild-type and miR-203 seed mutant of the 3′ Untranslated region (UTR) of USP26 were used to investigate whether USP26 is a target of miR-203. Effects of increasing miR-203 using MIR203A/5P mimic on USP26 and Snail1 in the HET-1A, Kyse150 and TE-1 cell lines were performed using western blot and cycloheximide-based protein stability analysis. Effects of modulating miR-203 in Kyse150 and TE-1 cell lines on in vitro pro-metastatic effects were analyzed by invasion assay, scratch wound-healing assay, and chemosensitivity to 5-fluoruracil (5-FU). In vivo lung metastasis assay was used to study the effect of modulating miR-203 in Kyse150 cells.

Results

SNAI1 mRNA and HSA/MIR203 was higher and lower, respectively, in EC patients compared to tumor-adjacent normal tissues. No changes in expression of USP26 mRNA were observed in these datasets. MIR/203 expression was downregulated whereas protein expression of both Snail1 and USP26 were higher in EC cell lines Kyse150 and TE-1 compared to normal esophageal cell line HET-1A. USP26 was predicted as a potential target of miR-203 by TargetScan Release 2.0. Reporter assays confirmed USP26 as a target of miR-203 in the EC cell lines. Transfection of EC cell lines with MIR203 mimic decreased USP26 protein expression and Snail1 protein stability indicating the ability of miR-203 to regulate Snail1 protein levels via USP26. Exogenous increase in miR-203 in the EC cell lines significantly inhibited Snail-1 mediated in vitro pro-metastatic function of invasion, wound-healing, and increased chemosensitivity to 5-FU. Finally, overexpression of miR-203 inhibited in vivo lung metastasis of Kyse150 cells, which was reversed following overexpression of USP26, indicating a direct role of miR-203-mediated regulation of USP26 in metastatic progression of EC.

Conclusions

Cumulatively, these results establish an important mechanism by which decrease in miR-203 expression potentiates metastatic progression in EC via USP26-mediated stabilization of Snail1. Hence, miR-203 can serve as a biomarker of metastasis in EC and is a potential target for therapeutic intervention in EC.

Exploring the Metabolic Vulnerabilities of Epithelial-Mesenchymal Transition in Breast Cancer

Metastasis and drug resistance are the leading causes of death for breast cancer patients. Epithelial-mesenchymal transition (EMT), a transition from polarized epithelial cells to motile mesenchymal cells mediated by a series of activation signals, confers breast tumor cells with enhanced stem cell, invasive, and metastatic properties. Metabolic reprogramming is an emerging hallmark of cancer cells, which have a complex mutual effect with EMT process. Under hypoxic and nutrient-deprived conditions, metabolic rewiring can rapidly provide ATP and sufficient metabolic intermediates for fueling breast cancer metastasis and progression. In this review, we primarily focus on how these altered metabolic phenotypes of breast tumor cells activate the EMT transcription factors and induce the EMT process to further promote metastasis and resistance to therapy. This review is divided to glucose, lipid, and amino acid metabolism to explore for potential metabolic vulnerabilities, which may provide new insights for blocking the EMT process in breast cancer.