EMT and inflammation: inseparable actors of cancer progression

Characterization of Osteoarthritis in a Medial Meniscectomy-Induced Animal Model Using Contrast-Enhanced X-ray Microtomography

The aim of this study was to clarify degradation characteristics in each tissue of the knee complex of a medial meniscectomy (MMx)-induced knee osteoarthritis (KOA) animal model using classical methods and an alternative comprehensive evaluation method called contrast-enhanced X-ray micro-computed tomography (CEX-μCT), which was developed in the study. Surgical MMx was performed in the right knee joints of five male Wistar rats to induce KOA. At four weeks post-surgery, the synovitis was evaluated using quantitative polymerase chain reaction (qPCR). Degradations of the articular cartilage of the tibial plateau were evaluated using classical methods and CEX-μCT. Evaluation of the synovitis demonstrated significantly increased expression levels of inflammation-associated marker genes in MMx-treated knees compared with those in sham-treated knees. Evaluation of the articular cartilage using classical methods showed that MMx fully induced degradation of the cartilage. Evaluation using CEX-μCT showed that local areas of the medial cartilage of the tibial plateau were significantly reduced in MMx-treated knees compared with those in sham-treated knees. On the other hand, total cartilage volumes were significantly increased in MMx-treated knees. On the basis of the findings of this study, the method could be relevant to study new treatments in KOA research.

Gain-of-Function Mutations in p53 in Cancer Invasiveness and Metastasis

Forty years of research has proven beyond any doubt that p53 is a key regulator of many aspects of cellular physiology. It is best known for its tumor suppressor function, but it is also a regulator of processes important for maintenance of homeostasis and stress response. Its activity is generally antiproliferative and when the cell is damaged beyond repair or intensely stressed the p53 protein contributes to apoptosis. Given its key role in preventing cancer it is no wonder that it is the most frequently mutated gene in human cancer. Surprisingly, a subset of missense mutations occurring in p53 (gain-of-function) cause it to lose its suppressor activity and acquire new functionalities that turn the tumor suppressor protein into an oncoprotein. A solid body of evidence exists demonstrating increased malignancy of cancers with mutated p53 in all aspects considered “hallmarks of cancer”. In this review, we summarize current findings concerning the cellular processes altered by gain-of-function mutations in p53 and their influence on cancer invasiveness and metastasis. We also present the variety of molecular mechanisms regulating these processes, including microRNA, direct transcriptional regulation, protein–protein interactions, and more.

Epithelial to Mesenchymal Transition: A Mechanism that Fuels Cancer Radio/Chemoresistance

Epithelial to mesenchymal transition (EMT) contributes to tumor progression, cancer cell invasion, and therapy resistance. EMT is regulated by transcription factors such as the protein products of the SNAI gene family, which inhibits the expression of epithelial genes. Several signaling pathways, such as TGF-beta1, IL-6, Akt, and Erk1/2, trigger EMT responses. Besides regulatory transcription factors, RNA molecules without protein translation, micro RNAs, and long non-coding RNAs also assist in the initialization of the EMT gene cluster. A challenging novel aspect of EMT research is the investigation of the interplay between tumor microenvironments and EMT. Several microenvironmental factors, including fibroblasts and myofibroblasts, as well as inflammatory, immune, and endothelial cells, induce EMT in tumor cells. EMT tumor cells change their adverse microenvironment into a tumor friendly neighborhood, loaded with stromal regulatory T cells, exhausted CD8⁺ T cells, and M2 (protumor) macrophages. Several EMT inhibitory mechanisms are instrumental in reversing EMT or targeting EMT cells. Currently, these mechanisms are also significant for clinical use.

Immune cell infiltrate at the utero-placental interface is altered in placenta accreta spectrum disorders

PURPOSE

To characterize the immune cell infiltrate associated with maternal vascular remodeling in 12 cases of cesarean hysterectomy from women with placenta accreta spectrum (PAS) disorder.

METHODS

Myometrial vessels were evaluated by hematoxylin and eosin and immunohistochemistry stains on tissue microarrays that included samples from the myometrium, deep to the implantation site. Vessels were quantified based on physiologic conversion and immune cell infiltrates. Placental bed biopsies from cases of repeat cesarean section, and decidual vessels from delivered non-PAS placentas were used as controls.

RESULTS

Immune cells, predominantly macrophages and T-cells, were present as a band along the placental-myometrial interface in PAS cases. However, within the myometrium, the infiltrate showed a perivascular accentuation. The infiltrates around and within vessel walls were composed of T-cells (CD3) and macrophages (CD68), with fewer NK (CD56), Treg (FoxP3) and rare B-cells (CD20). Plasma cells (CD138) were absent. The majority of vessels with immune cell infiltrates had undergone complete or partial physiologic conversion by trophoblast. However, a subset of unconverted vessels in the myometrium had a similar immune cell infiltration. Control blood vessels showed a similar pattern of leukocytes infiltration in the decidua and placental bed biopsies, but with a lower density.

CONCLUSIONS

Our findings suggest that myometrial vascular changes in PAS resemble the physiological changes of vessels noted in the implantation site of normal pregnancies. The presence of perivascular immune cell infiltrates in the absence of adjacent trophoblast suggests that the process may be initiated by paracrine effects rather than direct contact or endovascular growth of trophoblast.

CXCL11-CXCR3 Axis Mediates Tumor Lymphatic Cross Talk and Inflammation-Induced Tumor, Promoting Pathways in Head and Neck Cancers

Tumor metastasis to the draining lymph nodes is critical in patient prognosis and is tightly regulated by molecular interactions mediated by lymphatic endothelial cells (LECs). The underlying mechanisms remain undefined in the head and neck squamous cell carcinomas (HNSCCs). Using HNSCC cells and LECs we determined the mechanisms mediating tumor-lymphatic cross talk. The effects of a pentacyclic triterpenoid, methyl 2-trifluoromethyl-3,11-dioxoolean-1,12-dien-30-oate (CF₃DODA-Me), a potent anticancer agent, were studied on cancer-lymphatic interactions. In response to inflammation, LECs induced the chemokine (C-X-C motif) ligand 9/10/11 chemokines with a concomitant increase in the chemokine (C-X-C motif) receptor 3 (CXCR3) in tumor cells. CF₃DODA-Me showed antiproliferative effects on tumor cells, altered cellular bioenergetics, suppressed matrix metalloproteinases and chemokine receptors, and the induction of CXCL11-CXCR3 axis and phosphatidylinositol 3-kinase/AKT pathways. Tumor cell migration to LECs was inhibited by blocking CXCL11 whereas recombinant CXCL11 significantly induced tumor migration, epithelial-to-mesenchymal transition, and matrix remodeling. Immunohistochemical analysis of HNSCC tumor arrays showed enhanced expression of CXCR3 and increased lymphatic vessel infiltration. Furthermore, The Cancer Genome Atlas RNA-sequencing data from HNSCC patients also showed a positive correlation between CXCR3 expression and lymphovascular invasion. Collectively, our data suggest a novel mechanism for cross talk between the LECs and HNSCC tumors through the CXCR3-CXCL11 axis and elucidate the role of the triterpenoid CF₃DODA-Me in abrogating several of these tumor-promoting pathways.

In vitro and bioinformatics mechanistic-based approach for cadmium carcinogenicity understanding

Cadmium is a toxic metal able to enter the cells through channels and transport pathways dedicated to essential ions, leading, among others, to the dysregulation of divalent ions homeostasis. Despite its recognized human carcinogenicity, the mechanisms are still under investigation. A powerful tool for mechanistic studies of carcinogenesis is the Cell Transformation Assay (CTA). We have isolated and characterized by whole genome microarray and bioinformatics analysis of differentially expressed genes (DEGs) cadmium-transformed cells from different foci (F1, F2, and F3) at the end of CTA (6 weeks). The systematic analysis of up- and down-regulated transcripts and the comparison of DEGs in transformed cells evidence different functional targets and the complex picture of cadmium-induced transformation. Only 34 in common DEGs are found in cells from all foci, and among these, only 4 genes are jointly up-regulated (Ccl2, Ccl5, IL6 and Spp1), all responsible for cytokines/chemokines coding. Most in common DEGs are down-regulated, suggesting that the switching-off of specific functions plays a major role in this process. In addition, the comparison of dysregulated pathways immediately after cadmium treatment with those in transformed cells provides a valuable means to the comprehension of the overall process.

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Cell transformation Assay and toxicogenomics are integrated to study cadmium carcinogenesis mechanisms

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Inflammatory response is the only common feature in Cd-transformed cells from all different foci

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Switching-off of specific functions plays a major role in Cd-induced carcinogenesis

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Comparison of triggering signals and deregulated pathways in transformed cells provides hints on cadmium mechanisms

Silencing of HOXB9 suppresses cellular proliferation, angiogenesis, migration and invasion of prostate cancer cells

The Homeobox B9 (HOXB9) is a homeodomain-containing transcription factor that participates in the progression of various malignancies. Nevertheless, the functional role of HOXB9 in prostate cancer cells is largely unknown. Hence, we aimed to address the effect of HOXB9 on the progression of prostate cancer cells. Small interfering RNA (siRNA) against HOXB9 was used to downregulate HOXB9 expression in PC3 and DU145 cells. Western blotting was performed to detect the expression levels of HOXB9 and other related proteins. Cell proliferation was tested by the Cell Counting Kit-8 (CCK-8) and cell cycle and apoptosis were investigated by flow cytometry. Angiogenesis was examined using tube formation assays The Transwell assays were carried out to assess the migratory and invasive capacities of cells. Here, we found that HOXB9 knockdown significantly reduced cell proliferation via inducing cell cycle arrest at G1 phase. This treatment also reduced angiogenesis, migration and invasion abilities of PC3 and DU145 cells in vitro. We also found that HOXB9 knockdown inhibits the activation of the PI3K/AKT signaling pathway in prostate cancer cells. In conclusion, our findings revealed that HOXB9 promotes prostate cancer progression and might be a novel and effective therapeutic target for human prostate cancer.

Fibronectin in Cancer: Friend or Foe

The role of fibronectin (FN) in tumorigenesis and malignant progression has been highly controversial. Cancerous FN plays a tumor-suppressive role, whereas it is pro-metastatic and associated with poor prognosis. Interestingly, FN matrix deposited in the tumor microenvironments (TMEs) promotes tumor progression but is paradoxically related to a better prognosis. Here, we justify how FN impacts tumor transformation and subsequently metastatic progression. Next, we try to reconcile and rationalize the seemingly conflicting roles of FN in cancer and TMEs. Finally, we propose future perspectives for potential FN-based therapeutic strategies.

Contribution of Angiogenesis to Inflammation and Cancer

During carcinogenesis, advanced tumors are surrounded by both stromal and immune cells, which support tumor development. In addition, inflammation and angiogenesis are processes that play important roles in the development of cancer, from the initiation of carcinogenesis, tumor in situ and advanced stages of cancer. During acute inflammation, vascular hyperpermeability allows inflammatory mediators and immune response cells, including leukocytes and monocytes/macrophages, to infiltrate the site of damage. As a factor that regulates vascular permeability, vascular endothelial growth factor (VEGF) also plays a vital role as a multifunctional molecule and growth factor. Furthermore, stromal and immune cells secrete soluble factors that activate endothelial cells and favor their transmigration to eliminate the aggressive agent. In this review, we present a comprehensive view of both the relationship between chronic inflammation and angiogenesis during carcinogenesis and the participation of endothelial cells in the inflammatory process. In addition, the regulatory mechanisms that contribute to the endothelium returning to its basal permeability state after acute inflammation are discussed. Moreover, the manner in which immune cells participate in pathological angiogenesis release pro-angiogenic factors that contribute to early tumor vascularization, even before the angiogenic switch occurs, is also examined. Also, we discuss the role of hypoxia as a mechanism that drives the acquisition of tumor hallmarks that make certain cancers more aggressive. Finally, some combinations of therapies that inhibit the angiogenesis process and that may be a successful strategy for cancer patients are indicated.

Inflammation and Cancer: Triggers, Mechanisms, and Consequences

Inflammation predisposes to the development of cancer and promotes all stages of tumorigenesis. Cancer cells, as well as surrounding stromal and inflammatory cells, engage in well-orchestrated reciprocal interactions to form an inflammatory tumor microenvironment (TME). Cells within the TME are highly plastic, continuously changing their phenotypic and functional characteristics. Here, we review the origins of inflammation in tumors, and the mechanisms whereby inflammation drives tumor initiation, growth, progression, and metastasis. We discuss how tumor-promoting inflammation closely resembles inflammatory processes typically found during development, immunity, maintenance of tissue homeostasis, or tissue repair and illuminate the distinctions between tissue-protective and pro-tumorigenic inflammation, including spatiotemporal considerations. Defining the cornerstone rules of engagement governing molecular and cellular mechanisms of tumor-promoting inflammation will be essential for further development of anti-cancer therapies.

Exploiting Current Understanding of Hypoxia Mediated Tumour Progression for Nanotherapeutic Development

Hypoxia is one of the most common phenotypes of malignant tumours. Hypoxia leads to the increased activity of hypoxia-inducible factors (HIFs), which regulate the expression of genes controlling a raft of pro-tumour phenotypes. These include maintenance of the cancer stem cell compartment, epithelial-mesenchymal transition (EMT), angiogenesis, immunosuppression, and metabolic reprogramming. Hypoxia can also contribute to the tumour progression in a HIF-independent manner via the activation of a complex signalling network pathway, including JAK-STAT, RhoA/ROCK, NF-κB and PI3/AKT. Recent studies suggest that nanotherapeutics offer a unique opportunity to target the hypoxic microenvironment, enhancing the therapeutic window of conventional therapeutics. In this review, we summarise recent advances in understanding the impact of hypoxia on tumour progression, while outlining possible nanotherapeutic approaches for overcoming hypoxia-mediated resistance.

The Role of Serine Peptidase Inhibitor Kazal Type 13 (SPINK13) as a Clinicopathological and Prognostic Biomarker in Patients with Clear Cell Renal Cell Carcinoma

Background

The serine peptidase inhibitor Kazal type 13 (SPINK13) gene has tumor suppressor activity, but its role in renal cell carcinoma (RCC) remains unknown. This study aimed to investigate mRNA expression of SPINK13 in clear cell renal cell carcinoma (CCRCC) in human tissue and to use bioinformatics data to investigate the role of SPINK13 expression as a clinicopathological and prognostic biomarker for patients with CCRCC.

Material/Methods

Patients with CCRCC (N=533) with available RNA sequence data from The Cancer Genome Atlas (TCGA)-CCRCC database were analyzed with patients who had a tissue diagnosis of CCRCC (N=305) at the Fudan University Shanghai Cancer Center (FUSCC). Differential transcriptional and proteome expression profiles were obtained from the ONCOMINE cancer microarray database, TCGA, and the Human Protein Atlas (HPA) database. Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) measured SPINK13 mRNA expression in 305 samples of CCRCC tissue from the FUSCC. The effects of clinicopathological parameters on progression-free survival (PFS) and overall survival (OS) were analyzed using the Kaplan-Meier and log-rank test.

Results

Transcriptional and proteome expression of SPINK13 were significantly increased CCRCC tissue samples. Increased SPINK13 mRNA expression was significantly associated with reduced PFS and OS in 838 patients with CCRCC patients from the two independent cohorts, the FUSCC and the TCGA-CCRCC cohorts (p<0.01). Gene set enrichment analysis (GSEA) showed that SPINK13 expression was involved in complement, apical junction, epithelial-mesenchymal transition (EMT), glycolysis, hypoxia, and inflammation signaling pathways.

Conclusions

Increased expression of SPINK13 was associated with poor prognosis in patients with CCRCC.

Expression Analysis of the Mediators of Epithelial to Mesenchymal Transition and Early Risk Assessment of Therapeutic Failure in Laryngeal Carcinoma

Laryngeal squamous cell carcinoma (LSCC) is an aggressive malignancy which lacks early predictors of prognosis. Here, we hypothesized that expression and prognostic characterization of the critical mediators of epithelial to mesenchymal transition (EMT) may provide key information in this regard. Linear regression and multiple correspondence analyses were performed on immunohistochemical data obtained from 20 invasive tumors. Principal component and unsupervised hierarchical clustering were used to analyze the dataset patterns associating with LSCC metastatic profile. Survival and death risk assessments were performed using Kaplan–Meier and hazard ratio tests. Data mining analysis using CHAID decision tree and logistic regression analysis was applied to define the predictive value of the risk factors of tumor aggressiveness. Our analyses showed, that in invasive LSCC tumors, cells associating with a mesenchymal profile were likely to exhibit enhanced NOS2, TGF-β, and IL-17A expression levels, concomitantly to NF-κB nuclear translocation. IHC data deciphering determined that EMT induction was also linked to the enrichment of the tumors with CD68+ populations and IL-10 signal. Strikingly, dataset cluster analysis showed that these signatures could define distinct patterns of invasive tumors, where NOS2 associated with IL-10 expression, and TGF-β and IL-17A signals associated with MMP-9 activation. Decision tree analysis identified IL-17A as a possible predictor of LSCC aggressiveness. Altogether, our results show that distinct immunological patterns would support the acquisition of EMT features in invasive LSCC and suggest that IL-17A may be useful in the early identification of patients “at-risk” of therapeutic failure.

The effects of extracellular matrix rigidity on 3-dimensional cultures of amnion membrane cells

INTRODUCTION

To determine 3D growth of amnion membrane cells using soft substrate plates of various rigidities.

METHODS

Amnion epithelial (AEC) and mesenchymal cells (AMC) were cultured on 6-well soft substrate plates coated with matrigel and elastomer with rigidities of 0.5, 2, 8, 16, and 64 kPa (n = 3 each). Controls were cells in standard culture conditions. Cell morphology, spheroids' and sheets' formations and viability (bright field microscopy and crystal violet staining), and cellular transitions (vimentin/cytokeratin-18 [CK-18] ratios) were analyzed. A Student t-test was used for statistical analyses.

RESULTS

AECs in substrate rigidities between 2 and 8 kPa formed 3D features (spheroids and sheets) while retaining viability. Two kPa produced spheroids with epithelial characteristics (decrease in vimentin), and 8 kPa favored sheets. Transplantation and culture of AEC sheets with no matrix or elastomers, retained AECs' viability and maintained their epithelial characteristics. Optimum AMC growth was also between 2 and 8 kP A, with predominance of vimentin; however, AMCs did not form 3D structures. Lower and higher rigidities transitioned AMCs into AECs (decrease in vimentin).

DISCUSSION

Matrix rigidities between 2 and 8 kPa produced 3D structures of AECs (spheroids and sheets), resembling amnion membranes' morphology and exhibiting regenerative capacity in utero. Although AMCs grew in similar rigidities, a lack of 3D structures support their dispersed character in the membrane matrix. Extreme rigidities transitioned AMCs into AECs, suggesting that AMCs are transient cells (reservoirs) in the matrix required for remodeling. Compromises in matrix rigidity can cause membrane dysfunction and lead to adverse pregnancy outcomes.

Knockdown of PTGS2 by CRISPR/CAS9 System Designates a New Potential Gene Target for Melanoma Treatment

CRISPR/Cas9 has become a powerful method to engineer genomes and to activate or to repress genes expression. As such, in cancer research CRISPR/Cas9 technology represents an efficient tool to dissect mechanisms of tumorigenesis and to discover novel targets for drug development. Here, we employed the CRISPR/Cas9 technology for studying the role of prostaglandin-endoperoxide synthase 2 (PTGS2) in melanoma development and progression. Melanoma is the most aggressive form of skin cancer with a median survival of less than 1 year. Although oncogene-targeted drugs and immune checkpoint inhibitors have demonstrated a significant success in improving overall survival in patients, related toxicity and emerging resistance are ongoing challenges. Gene therapy appears to be an appealing option to enhance the efficacy of currently available melanoma therapeutics leading to better patient prognosis. Several gene therapy targets have been identified and have proven to be effective against melanoma cells. Particularly, PTGS2 is frequently expressed in malignant melanomas and its expression significantly correlates with poor survival in patients. In this study we investigated on the effect of ptgs2 knockdown in B16F10 murine melanoma cells. Our results show that reduced expression of ptgs2 in melanoma cells: i) inhibits cell proliferation, migration, and invasiveness; ii) modulates immune response by impairing myeloid derived suppressor cell differentiation; iii) reduces tumor development and metastasis in vivo. Collectively, these findings indicate that ptgs2 could represent an ideal gene to be targeted to improve success rates in the development of new and highly selective drugs for melanoma treatment.

MiR-6838-5p suppresses cell metastasis and the EMT process in triple-negative breast cancer by targeting WNT3A to inhibit the Wnt pathway

BACKGROUND

Triple-negative breast cancer (TNBC) has become a common tumor that harms women's physical and mental health, as characterized by a relatively rapid recurrence and a high incidence of brain metastasis. Research increasingly suggests that microRNAs play key roles in the progress of TNBC. However, the function of miR-6838-5p in TNBC has not yet been reported, and requires additional exploration.

METHODS

In the present study, we uncovered miR-6838-5p expression in TNBC cells via a quantitative reverse transcriptase-polymerase chain reaction. Functionally, the impacts of up-regulated or down-regulated miR-6838-5p on TNBC invasiveness, Wnt pathway activation and epithelial-mesenchymal transition (EMT) were investigated via transwell and western blot assays. Mechanical analyses were utilized to unmask the miR-6838-5p mechanism in TNBC, including luciferase reporter, western blot and RIP assays. Rescue assays manifested the miR-6838-5p/WNT3A network in TNBC invasiveness through the Wnt pathway.

RESULTS

Under-expressed miR-6838-5p was found in TNBC cells. Up-regulation of miR-6838-5p suppressed TNBC cell invasion, migration and blockade of the Wnt pathway. However, down-regulation of miR-6838-5p led to opposite results. Furthermore, we found, via luciferase reporter, western blot and RIP assays, that miR-6838-5p could bind with WNT3A and negatively regulate WNT3A expression. Through rescue experiments, we demonstrated that the overexpression of WNT3A partially rescued the miR-6838-5p overexpression-mediated inhibitory effect, and knockdown of WNT3A partially rescued the miR-6838-5p suppression-mediated promotive effect on the progression of TNBC.

CONCLUSIONS

In summary, the results of the present study indicate that miR-6838-5p suppresses cell proliferation, metastasis and the EMT process in TNBC by targeting WNT3A to inhibit the Wnt pathway, which may provide a new insight into the therapeutic strategies of TNBC.

Tumor Budding and Prognosis in Gastric Adenocarcinoma

Tumor budding has been associated with poor prognosis in several cancer types, but its significance in gastric cancer is unknown. The aim of this study was to assess the prognostic significance of tumor budding in gastric adenocarcinoma, and its main histologic types. Some 583 gastric adenocarcinoma patients who underwent surgery in Oulu University Hospital during the years 1983-2016 were included in this retrospective cohort study. Tumor budding was counted per 0.785 mm fields from the slides originally used for diagnostic purposes. Patients were divided into low-budding (<10 buds) and high-budding (≥10 buds) groups. Tumor budding was analyzed in relation to 5-year survival and overall survival. Cox regression was used to calculate hazard ratios (HR) with 95% confidence intervals (CI), adjusted for confounders. Determining tumor budding was difficult in diffuse-type cancer due to the uncohesive growth pattern of these tumors. Patients with high tumor budding had worse 5-year survival compared with patients with low tumor budding (adjusted HR, 1.55; 95% CI, 1.20-2.01). In intestinal-type adenocarcinomas, the high-budding group had significantly poorer 5-year survival compared with the low-budding group (adjusted HR, 1.57; 95% CI, 1.14-2.15). There were no differences in 5-year survival between the budding groups in the diffuse type adenocarcinoma. In conclusion, high tumor budding is an independent prognostic factor in gastric adenocarcinoma, but its value is limited to the intestinal type of gastric adenocarcinoma. In diffuse type gastric adenocarcinoma, the assessment of tumor budding is hardly feasible, and it does not have prognostic relevance.

The Escherichia coli protein toxin cytotoxic necrotizing factor 1 induces epithelial mesenchymal transition

Some toxigenic bacteria produce protein toxins with carcinogenic signatures, which either directly damage DNA or stimulate signalling pathways related to cancer. So far, however, only a few of them have been proved to favour the induction or progression of cancer. In this work, we report that the Rho-activating Escherichia coli protein toxin, cytotoxic necrotising factor 1 (CNF1), induces epithelial to mesenchymal transition (EMT) in intestinal epithelial cells. EMT is a crucial step in malignant tumour conversion and invasiveness. In the case of CNF1, it occurs by up-regulation of the transcription factors ZEB1 and Snail1, delocalisation of E-cadherin and β-catenin, activation of the serine/threonine kinase mTOR, accelerated wound healing, and invasion. However, our results highlight that nontransformed epithelial cells entail the presence of inflammatory factors, in addition to CNF1, to acquire a mesenchymal-like behaviour. All this suggests that the surrounding microenvironment, as well as the cell type, dramatically influences the CNF1 ability to promote carcinogenic traits.

FAM53A Affects Breast Cancer Cell Proliferation, Migration, and Invasion in a p53-Dependent Manner

Family with sequence similarity 53-member A (FAM53A) is an uncharacterized protein with a suspected but unclear role in tumorigenesis. In this study, we examined its role in breast cancer. Immunohistochemical staining of specimens from 199 cases of breast cancer demonstrated that FAM53A levels were negatively correlated with p53 status. In the p53 wild-type breast cancer cell line MCF-7, FAM53A overexpression inhibited cell migration, invasion, and proliferation, downregulated the expression of Snail, cyclin D1, RhoA, RhoC, and MMP9, and decreased mitogen-activated protein kinase kinase (MEK) and extracellular-signal regulated kinase (ERK) phosphorylation. Concurrently, it upregulated E-cadherin and p21 expression levels. Interestingly, opposite trends were observed in the p53-null breast cancer cell line MDA-MB-231. The MEK inhibitor PD98059 reduced the biological effects of FAM53A knockdown in MCF-7 cells and FAM53A overexpression in MDA-MB-231 cells, suggesting that FAM53A affects breast cancer through the MEK-ERK pathway. Silencing TP53 in MCF-7 cells and stably expressing wild-type p53 in MDA-MB-231 cells confirmed that the effects of FAM53A signaling through the MEK/ERK pathway depended on the p53 status of the cells. These results suggest that FAM53A acts as a tumor suppressor in p53-positive breast cancer by modulating the MEK-ERK pathway, but may be a potential candidate for targeted anticancer therapies in p53-negative breast cancer.

A High-Content Screening Approach to Identify MicroRNAs Against Head and Neck Cancer Cell Survival and EMT in an Inflammatory Microenvironment

Head and neck squamous cell carcinoma (HNSCC) is among the most common cancer types. Metastasis, the main cause of death by cancer, can be promoted by an inflammatory microenvironment, which induces epithelial-mesenchymal transition (EMT) through a NF-κB-mediated stabilization of Snail. Here, we aimed to explore how microRNAs (miRs) can affect cell survival and EMT in HNSCC cells under an inflammatory microenvironment. By using a high-content screening (HCS) approach, we evaluated alterations in morphometric parameters, as well as expression/localization of Snail/Slug, in HNSCC cells primed with TNF-α. Based on those quantitation, we established the optimal experimental conditions of EMT induction driven by TNF-α. Those conditions were applied to cells transfected with distinct miRs (N = 31), followed by clusterization of miRs based on alterations related to cell survival and EMT. The signaling pathways enriched with molecular targets from each group of miRs were identified by in silico analyses. Finally, cells were transfected with siRNAs against signaling pathways targeted by miRs with anti-survival/EMT effect and evaluated for alterations in cell survival and EMT. Overall, we observed that TNF-α, at 20 ng/ml, induced EMT-related changes in cell morphology, Snail/Slug expression, and cell migration. Predicted targets of miRs with anti-survival/EMT effect were enriched with targets of NF-κB, PI3K/ATK, and Wnt/beta catenin pathways. Strikingly, individual gene silencing of elements from those pathways, namely RELA (NF-kB), AKT1 (PI3K/AKT), and CTNNB1 (Wnt/beta catenin) reduced cell survival and/or expression of Snail/Slug in cells stimulated with TNF-α. As a whole, our HCS approach allowed for the identification of miRs capable of inhibiting cell survival and EMT considering the presence of an inflammatory microenvironment, also indicating the common signaling pathways and molecular targets most likely to underlie those alterations. These findings may contribute to the development of targeted therapies against HNSCC.

Monospecies and polymicrobial biofilms differentially regulate the phenotype of genotype-specific oral cancer cells

Microbial infection has been shown to involve in oral carcinogenesis; however, the underlying mechanisms remain poorly understood. The present study aimed to characterize the growth of oral microorganisms as both monospecies and polymicrobial biofilms and determine the effects of their products on oral keratinocytes. Candida albicans (ALC3), Actinomyces naeslundii (AN) and Streptococcus mutans (SM) biofilms or a combination of these (TRI) were grown in flow-cell system for 24 h. The biofilms were subjected to fluorescent in situ hybridization using species-specific probes and analysed using confocal laser scanning microscopy. The effluent derived from each biofilm was collected and incubated with malignant (H357) and normal (OKF6) oral keratinocytes to assess extracellular matrix adhesion, epithelial-mesenchymal transition (EMT) and cytokines expression. Incubation of OKF6 with ALC3 and TRI effluent significantly decreased adhesion of the oral keratinocyte to collagen I, whereas incubation of H357 with similar effluent increased adhesion of the oral keratinocyte to laminin I, significantly when compared with incubation with artificial saliva containing serum-free medium (NE; P < 0.05). In OKF6, changes in E-cadherin and vimentin expression were not consistent with EMT although there was evidence of a mesenchymal to epithelial transition in malignant oral keratinocytes incubated with AN and SM effluent. A significant increase of pro-inflammatory cytokines expression, particularly interleukin (IL)-6 and IL-8, was observed when H357 was incubated with all biofilm effluents after 2- and 24-h incubation when compared with NE (P < 0.05). In conclusion, C.albicans, A.naeslundii and S.mutans form polymicrobial biofilms which differentially modulate malignant phenotype of oral keratinocytes.

STRA6 exerts oncogenic role in gastric tumorigenesis by acting as a crucial target of miR-873

Background

Increasing evidence shows that stimulated by retinoic acid 6 (STRA6) participates in regulating multiple cancers. However, the biological roles of STRA6 in gastric cancer (GC) remain unknown. This study aimed to investigate the biological function of STRA6 and reveal the underlying mechanism of its dysregulation in GC.

Methods

The expression level of STRA6 was detected through quantitative real-time PCR and Western blot analysis. The effects of STRA6 on the proliferation of GC cells were studied through CCK-8 proliferation, colony formation and 5-ethynyl-2′-deoxyuridine (EdU) assays. The effects of STRA6 on migration and invasion were detected via wound healing and Transwell assays. Upstream miRNAs, which might regulate STRA6 expression, was predicted through bioinformatics analysis. Their interaction was further confirmed through dual-luciferase reporter assays and rescue experiments.

Results

STRA6 was up-regulated in GC and enhanced the proliferation and metastasis of GC cells in vitro and in vivo. STRA6 knockdown could inhibit the Wnt/β-catenin signalling pathway. STRA6 was confirmed as an miR-873 target, which acted as a tumour suppressor in GC. Rescue assays showed that the repressing effect of miR-873 could be partially reversed by overexpressing STRA6.

Conclusions

STRA6 is down-regulated by miR-873 and plays an oncogenic role by activating Wnt/β-catenin signalling in GC.

Epigenetic Regulation of Inflammatory Cytokine-Induced Epithelial-To-Mesenchymal Cell Transition and Cancer Stem Cell Generation

The neoplastic transformation of normal to metastatic cancer cells is a complex multistep process involving the progressive accumulation of interacting genetic and epigenetic changes that alter gene function and affect cell physiology and homeostasis. Epigenetic changes including DNA methylation, histone modifications and changes in noncoding RNA expression, and deregulation of epigenetic processes can alter gene expression during the multistep process of carcinogenesis. Cancer progression and metastasis through an ‘invasion–metastasis cascade’ involving an epithelial-to-mesenchymal cell transition (EMT), the generation of cancer stem cells (CSCs), invasion of adjacent tissues, and dissemination are fueled by inflammation, which is considered a hallmark of cancer. Chronic inflammation is generated by inflammatory cytokines secreted by the tumor and the tumor-associated cells within the tumor microenvironment. Inflammatory cytokine signaling initiates signaling pathways leading to the activation of master transcription factors (TFs) such as Smads, STAT3, and NF-κB. Moreover, the same inflammatory responses also activate EMT-inducing TF (EMT-TF) families such as Snail, Twist, and Zeb, and epigenetic regulators including DNA and histone modifying enzymes and micoRNAs, through complex interconnected positive and negative feedback loops to regulate EMT and CSC generation. Here, we review the molecular regulatory feedback loops and networks involved in inflammatory cytokine-induced EMT and CSC generation.

Autophagy and Its Relationship to Epithelial to Mesenchymal Transition: When Autophagy Inhibition for Cancer Therapy Turns Counterproductive

The manipulation of autophagy for cancer therapy has gained recent interest in clinical settings. Although inhibition of autophagy is currently being used in clinical trials for the treatment of several malignancies, autophagy has been shown to have diverse implications for normal cell homeostasis, cancer cell survival, and signaling to cells in the tumor microenvironment. Among these implications and of relevance for cancer therapy, the autophagic process is known to be involved in the regulation of protein secretion, in tumor cell immunogenicity, and in the regulation of epithelial-to-mesenchymal transition (EMT), a critical step in the process of cancer cell invasion. In this work, we have reviewed recent evidence linking autophagy to the regulation of EMT in cancer and normal epithelial cells, and have discussed important implications for the manipulation of autophagy during cancer therapy.

Effect of MALAT1 Polymorphisms on Papillary Thyroid Cancer in a Chinese Population

Background: Long noncoding RNA MALAT1 has been previously reported in the carcinogenesis of several tumors, and its potential functional polymorphisms have also been investigated in various diseases. However, the relationship between these polymorphisms and the susceptibility of thyroid cancer has still been largely unknown. In the present study, we aimed to explore the association between MALAT1 polymorphisms and thyroid cancer (TC) susceptibility, as well as potential biological function in TC.

Methods: We conducted a case-control study with 1134 papillary thyroid cancer (PTC) patients and 1228 controls to evaluate the potential correlation between MALAT1 genetic variations (single nucleotide polymorphism, SNP) and the risk of PTC. More detailed molecular mechanisms were explored by luciferase assay, cell counting kit-8 (CCK-8), and flow cytometry.

Results: MALAT1 SNP rs619586 was identified as a significantly protective factor of PTC susceptibility (P = 0.017, OR= 0.76, 95%CI = 0.60-0.95). Further functional experiments of rs619586 indicated that G allele of rs619586 could significantly decrease MALAT1expression, reduce PTC proliferation, and directly increase PTC apoptosis.

Conclusions: Our findings suggested that MALAT1 SNP rs619586 could serve as a potential indicator for PTC susceptibility and pathogenesis.

Fluorene-9-bisphenol inhibits epithelial-mesenchymal transition of human endometrial cancer Ishikawa cells by repressing TGF-β signaling pathway

Fluorene-9-bisphenol (BHPF), a new derivative of bisphenol A (BPA), has been introduced for treatment with estrogen-related tumors, such as endometrial cancer. This study investigated the potential mechanism underlying the action of BHPF against endometrial cancer in vitro. We used the cell counting kit-8 (CCK8) method on Ishikawa cells to screen sub-lethal doses of BHPF and established the optimal concentration at which BHPF influenced the proliferation of Ishikawa cells. Effect of BHPF on cell migration and invasion was investigated by cell scratch assay and transwell assay, respectively. Expression levels of epithelial-mesenchymal transition (EMT)-related proteins were detected by Western blot analysis. BHPF was found to inhibit the proliferation of Ishikawa cells, whose migration and invasion abilities were also reduced. Western blot indicated that BHPF can significantly inhibit the EMT process of Ishikawa cells by blocking transforming growth factor-β (TGF-β) signaling pathway. This is the first report of the effect of BHPF on the biological behavior of endometrial cancer cells and its inhibition of endometrial cancer progression by repressing both endometrial cell proliferation and epithelial-mesenchymal transition, hence suggesting it as a novel anti-cancer drug. Graphical abstract Schematic representation of the molecular basis underlying BHPF treatment. BHPF repressed the EMT process by regulating EMT-related genes, such as E-cadherin, N-cadherin, and vimentin as well as the TGF-β signaling pathway-related genes, including p-Smad2/3 and slug, in a BHPF-dependent manner.

Interactions Between Anti-Vegf Therapy and Antitumor Immunity as a Potential Therapeutic Strategy in Colorectal Cancer

There is a growing corpus of evidence indicating that anti-VEGF therapy may normalize the abnormal tumor vasculature with the potential to re-program the tumor immune microenvironment to a more immunosupportive profile. Tumor vessel normalization increases tumor perfusion, and, consequently, oxygen and nutrient supply, and thus can be assumed to improve the general response to anticancer immunotherapy. The increased antitumor immunity responses seen following anti-VEGF therapy may also be associated with the inhibition of the immunosuppressive action deployed by VEGF on effector T cells. Bearing in mind the recent advances of combination immunotherapy, combinations of anti-VEGF therapy with immune checkpoint inhibitors now appear to represent an attractive strategy. Key to the successful implementation of a combination strategy for treating cancer is understanding the interaction of these two therapeutic interventions, particularly in regards to appropriate reprogramming of the tumor immune microenvironment to improve antitumor immunity.

Mining of Self-Organizing Map Gene-Expression Portraits Reveals Prognostic Stratification of HPV-Positive Head and Neck Squamous Cell Carcinoma

Patients (pts) with head and neck squamous cell carcinoma (HNSCC) have different epidemiologic, clinical, and outcome behaviors in relation to human papillomavirus (HPV) infection status, with HPV-positive patients having a 70% reduction in their risk of death. Little is known about the molecular heterogeneity in HPV-related cases. In the present study, we aim to disclose the molecular subtypes with potential biological and clinical relevance. Through a literature review, 11 studies were retrieved with a total of 346 gene-expression data points from HPV-positive HNSCC pts. Meta-analysis and self-organizing map (SOM) approaches were used to disclose relevant meta-gene portraits. Unsupervised consensus clustering provided evidence of three biological subtypes in HPV-positive HNSCC: Cl1, immune-related; Cl2, epithelial–mesenchymal transition-related; Cl3, proliferation-related. This stratification has a prognostic relevance, with Cl1 having the best outcome, Cl2 the worst, and Cl3 an intermediate survival rate. Compared to recent literature, which identified immune and keratinocyte subtypes in HPV-related HNSCC, we confirmed the former and we separated the latter into two clusters with different biological and prognostic characteristics. At present, this paper reports the largest meta-analysis of HPV-positive HNSCC studies and offers a promising molecular subtype classification. Upon further validation, this stratification could improve patient selection and pave the way for the development of a precision medicine therapeutic approach.

Metformin reverses mesenchymal phenotype of primary breast cancer cells through STAT3/NF-κB pathways

BACKGROUND

Breast cancer currently is the most frequently diagnosed neoplasm and the leading cause of death from cancer in women worldwide, which is mainly due to metastatic disease. Increasing our understanding of the molecular mechanisms leading to metastasis might thus improve the pharmacological management of the disease. Epithelial-mesenchymal transition (EMT) is a key factor that plays a major role in tumor metastasis. Some pro-inflammatory cytokines, like IL-6, have been shown to stimulate phenotypes consistent with EMT in transformed epithelial cells as well as in carcinoma cell lines. Since the EMT is one of the crucial steps for metastasis, we studied the effects of metformin (MTF) on EMT.

METHODS

Cytotoxic effect of MTF was evaluated in eight primary breast cancer cell cultures by crystal violet assay. EMT markers and downstream signaling molecules were measured by Western blot. The effect of MTF on cell proliferation and cell migration were analyzed by MTT and Boyden chamber assays respectively.

RESULTS

We observed that the response of cultured breast cancer primary cells to MTF varied; mesenchymal cells were resistant to 10 mM MTF and expressed Vimentin and SNAIL, which are associated with a mesenchymal phenotype, whereas epithelial cells were sensitive to this MTF dose, and expressed E-cadherin but not mesenchymal markers. Further, exposure of mesenchymal cells to MTF down-regulated both Vimentin and SNAIL as well as cell proliferation, but not cell migration. In an in vitro IL-6-induced EMT assay, primary breast cancer cells showing an epithelial phenotype underwent EMT upon exposure to IL-6, with concomitant activation of STAT3 and NF-κB; addition of MTF to IL-6-induced EMT reversed the expression of the mesenchymal markers Vimentin and SNAIL, decreased pSTAT3 Y705 and pNF-κB S536 and increased E-cadherin. In addition, downregulation of STAT3·activation was dependent on AMPK, but not NF-κB phosphorylation. Further, MTF inhibited cell proliferation and migration stimulated by IL-6.

CONCLUSION

These results suggest that MTF inhibits IL-6-induced EMT, cell proliferation, and migration of primary breast cancer cells by preventing the activation of STAT3 and NF-κB. STAT3 inactivation occurs through AMPK, but not NF-κB.

Phenotypic transition of tumor cells between epithelial- and mesenchymal-like state during adaptation to acidosis

Acidic microenvironment is an important feature of solid tumors that contributes to malignant transformation. Low extracellular pH could promote epithelial-mesenchymal transition (EMT) thereby endowing tumor cells with higher invasive capability. However, the relation between EMT and tumor cell proliferation under long-term acidic condition is still not fully understood. Here, we show that tumor cells have undergone a phenotypic transition from EMT to mesenchymal-epithelial transition (MET) during adaptation to acidosis, and is closely related with cell proliferative state. Under early stage of acidic stress, tumor cells entered a non-cycling quiescent state with mesenchymal phenotype and expressed high level of stemness genes. Whereas, after long-term acid culture (2 months), acid-adapted cells resumed proliferating but lost mesenchymal phenotype. Further, our results show that the acid-adapted cells have distinct proliferative mechanism from non-acid cells, as the G1-S transcriptional factor E2F1 protein was not recovered in the adapted cells. Meanwhile, mini-chromosome maintenance 7 (MCM7) is shown to regulate the EMT to MET phenotypic transition, and is required for proliferation of the adapted cells under acidic condition. MCM7 Knockdown promoted mesenchymal phenotype and inhibited proliferation of the acid-adapted cells. While, MCM7 overexpression inhibited acid-induced EMT and supported tumor cell proliferation under acidic condition. Thus, our study provides evidence that tumor cells display phenotypic plasticity that allows them to survive acid stress.

Oroxylin A Suppresses the Cell Proliferation, Migration, and EMT via NF-κB Signaling Pathway in Human Breast Cancer Cells

Oroxylin A is a natural extract and has been reported to have a remarkable anticancer function. However, the mechanism of its anticancer activity remains not quite clear. In this study, we examined the inhibiting effects of Oroxylin A on breast cancer cell proliferation, migration, and epithelial-mesenchymal transition (EMT) and its possible molecular mechanism. The cytoactive and inflammatory factors were analyzed via Cell Counting Kit-8 assay and ELISA assay, respectively. Flow cytometry and western blotting were used to assess the cell proliferation. In addition, a wound healing assay and transwell assay were used to detect cell invasion and migration. qRT-PCR and western blot were employed to determine the effect of Oroxylin A on the EMT formation. Moreover, expression level of protein related to NF-κB signaling pathway was determined by western blot. The results revealed that Oroxylin A attenuated the cytoactivity of MDA-MB-231 cells in a dose- and a time-dependent manner. Moreover, cell proliferation, invasion, and migration of breast cancer cells were inhibited by Oroxylin A compared to the control. The mRNA and protein expression levels of E-cadherin were remarkably increased while N-cadherin and Vimentin remarkably decreased. Besides, Oroxylin A suppressed the expression of inflammatory factors and NF-κB activation. Furthermore, we also found that supplement of TNF-α reversed the effects of Oroxylin A on the cell proliferation, invasion, migration, and EMT in breast cancer cells. Taken together, our results suggested that Oroxylin A inhibited the cell proliferation, invasion, migration, and EMT through inactivating NF-κB signaling pathway in human breast cancer cells. These findings strongly suggest that Oroxylin A could be a therapeutic potential candidate for the treatment of breast cancer.

Assessment of the Antiangiogenic and Anti-Inflammatory Properties of a Maslinic Acid Derivative and its Potentiation using Zinc Chloride

Maslinic acid is a pentacyclic triterpene with a plethora of biological activities, including anti-inflammatory, antioxidant, antimicrobial, cardioprotective, and antitumor effects. New derivatives with improved properties and broad-spectrum activity can be obtained following structural changes of the compound. The present study was aimed to characterize a benzylamide derivative of maslinic acid—benzyl (2α, 3β) 2,3-diacetoxy-olean⁻12-en-28-amide (EM2)—with respect to the anti-angiogenic and anti-inflammatory effects in two in vivo experimental models. Consequently, the compound showed good tolerability and lack of irritation in the chorioallantoic membrane assay with no impairment of the normal angiogenic process during the tested stages of development. In the acute ear inflammation murine model, application of EM2 induced a mild anti-inflammatory effect that was potentiated by the association with zinc chloride (ZnCl₂). A decrease in dermal thickness of mice ears was observed when EM2 and ZnCl₂ were applied separately or in combination. Moreover, hyalinization of the dermis appeared only when EM2 was associated with ZnCl₂, strongly suggesting the role of their combination in wound healing.

Wound fluids collected postoperatively from patients with breast cancer induce epithelial to mesenchymal transition but intraoperative radiotherapy impairs this effect by activating the radiation-induced bystander effect

Wound fluids (WF) are believed to play a role in the local recurrences by inducing an inflammatory process in scar tissue area. Given that most local relapse in primary breast cancer patients occur within the scar tissue area, researchers have investigated whether localized radiotherapy, such as intraoperative radiotherapy (IORT), could be more effective than postoperative RT in inhibiting local tumor recurrence. The epithelial-mesenchymal transition (EMT) program plays a critical role in promoting metastasis in epithelium-derived carcinoma. Given this background the main aim of the present study was to determine the mechanisms by which IORT decreases the tumorigenic potential of WF. We assumed that postoperative fluids from patients would activate the radiation-induced bystander effect (RIBE) in treated cells, thus altering the tumor microenvironment. To confirm this hypothesis, WF collected from patients after breast conserving surgery (BCS) alone, after BCS followed by IORT treatment or WF from BCS patients together with RIBE medium were incubated with MCF7 and MDA-MB-468 cells. Changes in the CSC phenotype, in EMT program and potential to migrate were performed to determine the possible role of WF on the migration of breast cancer cells. Our findings show that wound fluids stimulate the CSC phenotype and EMT program in breast cancer cell lines. This effect was partially abrogated when the cells were incubated in wound fluids collected from patients after breast-conserving surgery followed by IORT. Additionally, we confirmed the role of radiation-induced bystander effect in altering the properties of the WF to induce the CSC phenotype and EMT program.

Epithelial-Mesenchymal Plasticity in Organotropism Metastasis and Tumor Immune Escape

Most cancer deaths are due to metastasis, and almost all cancers have their preferential metastatic organs, known as “organotropism metastasis”. Epithelial-mesenchymal plasticity has been described as heterogeneous and dynamic cellular differentiation states, supported by emerging experimental evidence from both molecular and morphological levels. Many molecular factors regulating epithelial-mesenchymal plasticity have tissue-specific and non-redundant properties. Reciprocally, cellular epithelial-mesenchymal plasticity contributes to shaping organ-specific pre-metastatic niche (PMN) including distinct local immune landscapes, mainly through secreted bioactive molecular factors. Here, we summarize recent progress on the involvement of tumor epithelial-mesenchymal plasticity in driving organotropic metastasis and regulating the function of different immune cells in organ-specific metastasis.

CCL2 promotes cell migration by inducing epithelial-mesenchymal transition in oral squamous cell carcinoma

BACKGROUND

Although a few studies suggested that the chemokine CCL2 might be involved in the development of oral squamous cell carcinoma (OSCC), the exact mechanism remains unclear. In this study, we aimed to determine the resource of CCL2 in lesions and explored a potential mechanism that CCL2 promotes tumor progression. The study was an effort to provide new insights into the pathological role of CCL2 in OSCC.

METHODS

Specimens of OSCC and normal oral mucosa were stained using immunohistochemistry (IHC) to assess the CCL2 expression. Enzyme-linked immunosorbent assay (ELISA) was used to detect the difference of CCL2 between OSCC and normal oral mucosa cell lines. In addition, we treated OSCC cells with exogenous rCCL2 combined with or without CCL2 neutralizing antibody and then determined the changes of in epithelial-mesenchymal transition (EMT) markers and cell migration capacity using immunofluorescence, Western blotting, transwell migration, and wound healing assays.

RESULTS

We have found that CCL2 expression was upregulated significantly in both lesions and cell culture supernatant of OSCC compared with controls. IHC staining demonstrated that CCL2 expression was primarily located in the cytoplasm and cell membrane of cells. We have also found that rCCL2 could effectively induce EMT through upregulating Snail in OSCC cells, which was demonstrated by the decrease of E-cadherin and the increase of vimentin. In addition, we have found that CCL2 neutralizing antibody could block EMT induced by CCL2 in OSCC.

CONCLUSIONS

CCL2 secreted by cancer cells can promote cell migration by inducing EMT via paracrine or autocrine in OSCC.

QKI, a miR-200 target gene, suppresses epithelial-to-mesenchymal transition and tumor growth

The microRNA-200 (miR-200) family plays a major role in specifying epithelial phenotype by preventing expression of the transcription repressors ZEB1 and ZEB2, which are well-known regulators of the epithelial-to-mesenchymal transition (EMT) in epithelial tumors including oral squamous cell carcinoma (OSCC). Here, we elucidated whether miR-200 family members control RNA-binding protein quaking (QKI), a newly identified tumor suppressor that is regulated during EMT. We predicted that miR-200a and miR-200b could recognize QKI 3'-UTR by analyzing TargetScan and The Cancer Genome Atlas head and neck squamous cell carcinoma (HNSCC) dataset. Forced expression of miR-200b/a/429 inhibited expression of ZEB1/2 and decreased cell migration in OSCC cell lines CAL27 and HSC3. QKI expression was also suppressed by miR-200 overexpression, and the 3'-UTR of QKI mRNA was directly targeted by miR-200 in luciferase reporter assays. Interestingly, shRNA-mediated knockdown of QKI led to pronounced EMT and protumor effects in both in vitro and in vivo studies of OSCC. Furthermore, high expression of QKI protein is associated with favorable prognosis in surgically resected HNSCC and lung adenocarcinoma. In conclusion, QKI increases during EMT and is targeted by miR-200; while, it suppresses EMT and tumorigenesis. We suggest that QKI and miR-200 form a negative feedback loop to maintain homeostatic responses to EMT-inducing signals.

The cullin4A is up-regulated in chronic obstructive pulmonary disease patient and contributes to epithelial-mesenchymal transition in small airway epithelium

Background

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease with high morbidity and mortality. The most important pathophysiological change of COPD is airway obstruction. Airway obstruction can cause airflow restriction and obstructive ventilation dysfunction. Currently, many studies have shown that there is EMT phenomenon in the process of airway remodeling of COPD. Cullin4A (CUL4A) is an E3 ubiquitin ligase that interacts with other factors to form the E3 complex. Studies have shown that CLU4A is associated with EMT in non-small cell lung cancer and other cancers. However, its relationship with EMT in COPD has not been reported systematically. In this study, we detected the expression of CUL4A in lung epithelium of COPD patients. In addition, the regulatory effect and mechanism of CUL4A on EMT in COPD were clarified in small airway epithelial cells.

Methods

The expression of CUL4A was assessed by immunohistochemistry in lung epithelium specimens from smokers, non-smokers and patients with chronic obstructive pulmonary disease. The role of CUL4A on cigarette smoke extract (CSE)-induced epithelial-mesenchymal transition (EMT) in human small airway epithelial cells (HSAEpiCs) was assessed by silencing or overexpression CUL4A in vitro. Cigarette smoke is recognized as a high-risk factor in the induction of COPD, and its damage to the airway involves airway damage, airway inflammation and airway remodeling.

Results

The results shown that CUL4A expression in small airway epithelium was significantly increased in patients with COPD. We also observed a significant negative association between CUL4A and FEV₁%, a useful clinical marker for the diagnosis and evaluation of COPD severity, in small airway epithelial cells. In vitro, CSE-induced EMT is associated with high expression of CUL4A, and targeted silencing of CUL4A with shRNA inhibits CSE-induced EMT in human small airway epithelial cells.

Conclusions

Our results showed that CUL4A was overexpressed in lung epithelium of COPD patients, and CUL4A could regulate EMT of human small airway epithelium, which revealed a new mechanism of remodeling of small airway epithelium of COPD patients.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1048-4) contains supplementary material, which is available to authorized users.

Exploration of prognosis-related microRNA and transcription factor co-regulatory networks across cancer types

The study of cancer prognosis serves as an important part of cancer research. Large-scale cancer studies have identified numerous genes and microRNAs (miRNAs) associated with prognosis. These informative genes and miRNAs represent potential biomarkers to predict survival and to elucidate the molecular mechanism of tumour progression. MiRNAs and transcription factors (TFs) can work cooperatively as essential mediators of gene expression, and their dysregulation affects cancer prognosis. A panoramic view of cancer prognosis at the system level, considering the co-regulation roles of miRNA and TF, remains elusive. Here, we establish 12 prognosis-related miRNA-TF co-regulatory networks. The characteristics of prognostic target genes and their regulators in the network are depicted. Although the target genes and co-regulatory patterns exhibit cancer-specific properties, some miRNAs and TFs are highly conserved across cancers. We illustrate and interpret the roles of these conserved regulators by building a model associated with cancer hallmarks, functional enrichment analysis, network community detection, and exhaustive literature research. The elaborated system-level prognostic miRNA-TF co-regulation landscape, including the highlighted roles of conserved regulators, provides a novel and powerful insights into further biological and medical discoveries.

MEG3 affects the progression and chemoresistance of T-cell lymphoblastic lymphoma by suppressing epithelial-mesenchymal transition via the PI3K/mTOR pathway

Long noncoding RNAs (lncRNA) are emerging as integral functional and regulatory components in the development of different diseases including cancer. Maternally expressed gene 3 (MEG3), is a lncRNA, that has a depressed expression in multiple tumor types, including T-cell lymphoblastic lymphoma (T-LBL). However, the molecular mechanisms that regulate the tumorigenic functions of MEG3 in T-LBL remain largely unknown. In this study, we aimed to discover and identify the function of MEG3 in T-LBL tumorigenesis, epithelial-mesenchymal transition (EMT) and drug resistance, and explore their mechanisms of action. Knockdown MEG3 promoted the proliferation, migration, invasion, and drug resistance of T-LBL cells while overexpression of MEG3 gets the opposite results. The mechanism study showed that decreased MEG3 expression in T-LBL cells could activate PI3K/mTOR signaling pathways, increase the expression of p-glycoprotein and affect the expression of EMT markers for transforming to mesenchymal cells in vitro and in vivo. Together, these results indicate that MEG3 could inhibit the migration, invasion, and drug resistance in T-LBL cells by suppression of the PI3K/mTOR pathway. MEG3 might be a potential target, through which poor prognosis with high recurrence and drug resistance of T-LBL in a clinical setting could be reversed.

Response of breast cancer cells to IFNα-2b in 2D and 3D cell cultures

The effect of IFNα-2b on the migration, proliferation, and expression of epithelial and mesenchymal markers of MCF-7 tumor adenocarcinoma cells in 2D and 3D cell cultures was examined. A significant cytostatic effect of IFNα-2b on the tumor population was detected. It was found that changes in the expression of epithelial (CKs and EpCAM) and mesenchymal markers were caused by changing the growth type of the tumor population. IFNα-2b inhibited migration of tumor cells to the suspension fraction and promoted an increase in expression of CK and EpCAM in 2D and 3D cell cultures, but only in the 3D culture was expression of vimentin increased. IFNα-2b caused an increase in CK and EpCAM expression by 50.5% and 47.8%, respectively, compared with the control in the 2D cell culture. In the 3D cell culture this increase was 33% and 34%, respectively, compared with the control. IFNα-2b stimulated the differentiation and inhibited the migrational ability of tumor cells in the early stages of breast cancer development.

Crosstalk between cancer cells and tumor associated macrophages is required for mesenchymal circulating tumor cell-mediated colorectal cancer metastasis

Background

Tumor-associated macrophages (TAMs) are major components of tumor microenvironment that frequently associated with tumor metastasis in human cancers. Circulating tumor cell (CTC), originating from primary tumor sites, is considered to be the precursors of tumor metastasis. However, the regulatory mechanism of TAMs in CTC-mediated tumor metastasis still remains unclear.

Methods

Immunohistochemical staining was used to detect the macrophages infiltration (CD68 and CD163), epithelial–mesenchymal transition (EMT) markers (E-cadherin and Vimentin) expression in serial sections of human colorectal cancer (CRC) specimens. Then, the correlations between macrophages infiltration and clinicopathologic features, mesenchymal CTC ratio, and patients’ prognosis were analyzed. A co-culture assay in vitro was used to evaluate the role of TAMs on CRC EMT, migration and invasion, and ELISA, luciferase reporter assay and CHIP were performed to uncover the underlying mechanism. Furthermore, an in vivo model was carried out to confirm the effect of TAMs on mesenchymal CTC-mediated metastasis.

Results

Clinically, CD163⁺ TAMs infiltrated in invasive front was associated with EMT, mesenchymal CTC ratio, and poor prognosis in patients with CRC. CRC–conditioned macrophages regulated EMT program to enhance CRC cells migration and invasion by secreting IL6. TAMs-derived IL6 activated the JAK2/STAT3 pathway, and activated STAT3 transcriptionally inhibited the tumor suppressor miR-506-3p in CRC cells. miR-506-3p, a key miRNA regulating FoxQ1, was downregulated in CRC cells, resulting in increased FoxQ1 expression, which in turn led to the production of CCL2 that promoted macrophage recruitment. Inhibition of CCL2 or IL6 broke this loop and reduced macrophage migration and mesenchymal CTC-mediated metastasis, respectively.

Conclusions

Our data indicates that TAMs induce EMT program to enhance CRC migration, invasion, and CTC-mediated metastasis by regulating the JAK2/STAT3/miR-506-3p/FoxQ1 axis, which in turn leads to the production of CCL2 that promote macrophage recruitment, revealing a new cross-talk between immune cells and tumor cells in CRC microenvironment.

Electronic supplementary material

The online version of this article (10.1186/s12943-019-0976-4) contains supplementary material, which is available to authorized users.

Macrophage ERα promoted invasion of endometrial cancer cell by mTOR/KIF5B-mediated epithelial to mesenchymal transition

Tumor-associated macrophages (TAMs) exert tumor-promoting effects. There have been reports that estrogen receptors (ERs) are expressed on the infiltrating macrophages of endometriosis, ovarian cancer and lung cancer. However, the role of ERs in macrophages is not well characterized. In this study, we identified that ER alpha (ERα) expression on the macrophages of human endometrial cancer was positively correlated with cancer progression. Conditioned medium from selective ERα agonist-treated M2 macrophages induced the epithelial to mesenchymal transition (EMT) in endometrial cancer cells. However, this effect can be inhibited by ERα antagonist. Here, we showed that macrophages ERα-engaged abundantly produced chemokine (C-C motif) ligand 18 (CCL18), and its expression promoted the invasion of endometrial cancer cells by activating the extracellular signal-regulated kinase 1/2 pathway, whereas suppressing CCL18 abrogated these effects. Furthermore, we identified that CCL18 derived from TAMs upregulated KIF5B expression to promote EMT via activating the PI3K/AKT/mTOR signaling pathway in endometrial cancer. Overall, our findings show how ERα-engaged infiltrating macrophages initiate chronic inflammation and promote the aggressive progression of endometrial cancer cells. ERα-positive TAMs act as drivers of endometrial cancer, which may become a potential therapeutic target.

Targeting Oncogenic Nuclear Factor Kappa B Signaling with Redox-Active Agents for Cancer Treatment

SIGNIFICANCE

Nuclear factor kappa B (NF-κB) signaling is essential under physiologically relevant conditions. However, aberrant activation of this pathway plays a pertinent role in tumorigenesis and contributes to resistance. Recent Advances: The importance of the NF-κB pathway means that its targeting must be specific to avoid side effects. For many currently used therapeutics and those under development, the ability to generate reactive oxygen species (ROS) is a promising strategy.

CRITICAL ISSUES

As cancer cells exhibit greater ROS levels than their normal counterparts, they are more sensitive to additional ROS, which may be a potential therapeutic niche. It is known that ROS are involved in (i) the activation of NF-κB signaling, when in sublethal amounts; and (ii) high levels induce cytotoxicity resulting in apoptosis. Indeed, ROS-induced cytotoxicity is valuable for its capabilities in killing cancer cells, but establishing the potency of ROS for effective inhibition of NF-κB signaling is necessary. Indeed, some cancer treatments, currently used, activate NF-κB and may stimulate oncogenesis and confer resistance.

FUTURE DIRECTIONS

Thus, combinatorial approaches using ROS-generating agents alongside conventional therapeutics may prove an effective tactic to reduce NF-κB activity to kill cancer cells. One strategy is the use of thiosemicarbazones, which form redox-active metal complexes that generate high ROS levels to deliver potent antitumor activity. These agents also upregulate the metastasis suppressor, N-myc downstream regulated gene 1 (NDRG1), which functions as an NF-κB signaling inhibitor. It is proposed that targeting NF-κB signaling may proffer a new therapeutic niche to improve the efficacy of anticancer regimens.

miR-195-5p/NOTCH2-mediated EMT modulates IL-4 secretion in colorectal cancer to affect M2-like TAM polarization

Background

Tumor microenvironment (TME) is a complex environment containing tumor cells, tumor-associated macrophages (TAMs), interstitial cells, and non-cellular components. Epithelial–mesenchymal transition (EMT), as a major actor in cancer tumorigenicity and metastasis, was involved in the interaction between TAMs and tumor cells. However, the potential mechanisms of EMT and how EMT-programmed tumor cells affect M2-like TAMs still need further exploration.

Methods

An integrated analysis of nine CRC miRNA expression datasets was performed. Functional assays, including the EdU, clone formation, wound healing, and transwell assays, were used to determine the anticancer role of miR-195-5p in human CRC progression. Furthermore, RNA immunoprecipitation, RNA decay, and dual-luciferase reporter assays were used to determine the mechanism of miR-195-p CRC progression. Then co-culture, migration, and ELISA assays were applied to determine the role of miR-195-5p in macrophage recruitment and alternative polarization. Xenograft mouse models were used to determine the role of miR-195-5p in CRC tumorigenicity and TAM polarization in vivo.

Results

An integrated analysis confirmed that miR-195-5p was significantly downregulated in CRC tissues, and patients with a low level of miR-195-5p had significantly shortened overall survival as revealed by the TCGA-COAD dataset. Altered miR-195-5p in colon cancer cells led to distinct changes of proliferation, migration, invasion, and EMT. Mechanistically, miR-195-5p regulated NOTCH2 expression in a post-transcriptional manner by directly binding to 3′-UTR of the Notch2 mRNA. Subsequently, miR-195-5p/NOTCH2 suppressed GATA3-mediated IL-4 secretion in CRC cells and ultimately inhibited M2-like TAM polarization.

Conclusions

miR-195-5p may play a vital role in regulating NOTCH2-mediated tumor cell EMT, thereby affecting IL-4-related M2-like TAM polarization in CRC.

Electronic supplementary material

The online version of this article (10.1186/s13045-019-0708-7) contains supplementary material, which is available to authorized users.

Female-biased embryonic death from inflammation induced by genomic instability

Genomic instability (GIN) can trigger cellular responses including checkpoint activation, senescence, and inflammation ^1,2. Though extensively studied in cell culture and cancer paradigms, little is known about the impact of GIN during embryonic development, a period of rapid cellular proliferation. We report that GIN-causing mutations in the MCM2–7 DNA replicative helicase ^3,4 render female mouse embryos to be dramatically more susceptible than males to embryonic lethality. This bias was not attributable to X-inactivation defects, differential replication licensing, or X vs Y chromosome size, but rather “maleness,” since XX embryos could be rescued by transgene-mediated sex reversal or testosterone (T) administration. The ability of exogenous or endogenous T to protect embryos was related to its anti-inflammatory properties ⁵. The NSAID ibuprofen rescued female embryos containing mutations not only in MCM genes but also Fancm, which like MCM mutants have elevated GIN (micronuclei) from compromised replication fork repair ⁶. Additionally, deficiency for the anti-inflammatory IL10 receptor was synthetically lethal with the Mcm4^Chaos3 helicase mutant. Our experiments indicate that DNA replication-associated DNA damage during development induces inflammation that is preferentially lethal to female embryos, whereas male embryos are protected by high levels of intrinsic T.

HMGB1 as a Potential Biomarker and Therapeutic Target for Malignant Mesothelioma

Malignant mesothelioma (MM) is a rare, aggressive, and highly lethal cancer that is substantially induced by exposure to asbestos fibers. High-mobility group box 1 (HMGB1) is an intriguing proinflammatory molecule involved in MM. In this review, we describe the possible crucial roles of HMGB1 in carcinogenic mechanisms based on in vivo and in vitro experimental evidence and outline the clinical findings of epidemiological investigations regarding the possible roles of HMGB1 as a biomarker for MM. We conclude that novel strategies targeting HMGB1 may suppress MM cells and interfere with asbestos-induced inflammation.

The emerging roles of macrophages in cancer metastasis and response to chemotherapy

Macrophages represent a heterogeneous group of cells, capable of carrying out distinct functions in a variety of organs and tissues. Even within individual tissues, their functions can vary with location. Tumor-associated macrophages (TAMs) specialize into three major subtypes that carry out multiple tasks simultaneously. This is especially true in the context of metastasis, where TAMs establish most of the cellular and molecular prerequisites for successful cancer cell dissemination and seeding to the secondary site. Perivascular TAMs operate in the perivascular niche, where they promote tumor angiogenesis and aid in the assembly of intravasation sites called tumor microenvironment of metastasis (TMEM). Streaming TAMs co-migrate with tumor cells (irrespective of the perivascular niche) and promote matrix remodeling, tumor cell invasiveness, and an immunosuppressive local microenvironment. Premetastatic TAMs are recruited to the premetastatic niche, where they can assist in tumor cell extravasation, seeding, and metastatic colonization. The dynamic interplay between TAMs and tumor cells can also modify the ability of the latter to resist cytotoxic chemotherapy (a phenotype known as environment-mediated drug resistance) and induce chemotherapy-mediated pro-metastatic microenvironmental changes. These observations suggest that future therapeutics should be designed to target TAMs with the aim of suppressing the metastatic potential of tumors and rendering chemotherapy more efficient.

Traditional Chinese medicine as targeted treatment for epithelial-mesenchymal transition-induced cancer progression

The epithelial-mesenchymal transition (EMT) program, which loosens cell-cell adhesion complexes, endows cells with enhanced migratory and invasive properties. Furthermore, this process facilitates both the development of drug resistance and immunosuppression by tumor cells, which preclude the successful treatment of cancer. Recent research has demonstrated that many signaling pathways are involved in EMT progression. In addition, cancer stem cells (CSCs), vasculogenic mimicry (VM) and the tumor-related immune microenvironment all play important roles in tumor formation. However, there are few reports on the relationships between EMT and these factors. In addition, in recent years, traditional Chinese medicine (TCM) has developed a unique system for treating cancer. In this review, we summarize the crucial signaling pathways associated with the EMT process in cancer patients and discuss the interconnections between EMT and other molecular factors (such as CSCs, VM, and the tumor-related immune microenvironment). We attempt to identify common regulators that might be potential therapeutic targets to thereby optimize tumor treatment. In addition, we outline recent research on TCM approaches that target EMT and thereby provide a foundation for further research on the exact mechanisms by which TCMs affect EMT in cancer.

Getting TANned: How the tumor microenvironment drives neutrophil recruitment

The directed migration of neutrophils to sites of injury or infection is mediated by complex networks of chemoattractant-receptor signaling cascades. The recent appreciation of neutrophils as active participants in tumor progression and metastasis has drawn attention to a number of chemokine-receptor systems that may drive their recruitment to tumors. However, the dynamic nature of the tumor microenvironment (TME) along with the phenotypic diversity among tumor-associated neutrophils (TANs) call for a more comprehensive approach to understand neutrophil trafficking to tumors. Here, we review recent advances in understanding how guidance cues underlie neutrophil migration to primary and secondary tumor sites. We also discuss how the presence of other myeloid cells, such as functionally diverse subsets of tumor-associated macrophages (TAMs), can further influence neutrophil accumulation in tumors. Finally, we highlight the importance of hypoxia sensing in localizing TAMs and TANs in the tumor niche and provide a cohesive view on how both myeloid cell types shape TME-associated extracellular matrix organization, which in turn contribute to tumor progression.