Twist predicts poor outcome of patients with astrocytic glioma

A comprehensive exploration of twist1 to identify a biomarker for tumor immunity and prognosis in pan-cancer

Twist1 has been identified as a critical gene in tumor, but current study of this gene remains limitative. This study aims to investigate its roles and potential mechanisms across pan-cancer. The study used various databases and computational techniques to analyze twist's RNA expression, clinical data, gene mutations, tumor stemness, tumor microenvironment, immune regulation. Furthermore, the experimental method of fluorescence staining was carried out to identify twist1 expression in various tumor masses. After analyzing the protein-protein interaction of TWIST, enrichment analysis and predictive potential drugs were performed, and molecular docking was conducted to validate. We found that twist1 expression was significantly higher in various types of cancer and associated with tumor stage, grade, and poor prognosis in multiple cancers. Differential expression of twist1 was linked to gene mutation, RNA modifications, and tumor stemness. Additionally, twist1 expression was positively associated with tumor immunoregulation and immune checkpoint. Salinomycin, klugline, isocephaelince, manassantin B, and pimonidazole are predictive potential drugs targeting TWIST1. This study revealed that twist1 plays an important role in tumor, and might be a curial marker in tumor diagnose and prognosis. The study also highlighted twist1 as a promising therapeutic target for cancer treatment and provided a foundation for future research.

Glioblastoma Microenvironment and Invasiveness: New Insights and Therapeutic Targets

Glioblastoma (GBM) is the most common and malignant primary brain cancer in adults. Without treatment the mean patient survival is approximately 6 months, which can be extended to 15 months with the use of multimodal therapies. The low effectiveness of GBM therapies is mainly due to the tumor infiltration into the healthy brain tissue, which depends on GBM cells' interaction with the tumor microenvironment (TME). The interaction of GBM cells with the TME involves cellular components such as stem-like cells, glia, endothelial cells, and non-cellular components such as the extracellular matrix, enhanced hypoxia, and soluble factors such as adenosine, which promote GBM's invasiveness. However, here we highlight the role of 3D patient-derived glioblastoma organoids cultures as a new platform for study of the modeling of TME and invasiveness. In this review, the mechanisms involved in GBM-microenvironment interaction are described and discussed, proposing potential prognosis biomarkers and new therapeutic targets.

Are We Benign? What Can Wnt Signaling Pathway and Epithelial to Mesenchymal Transition Tell Us about Intracranial Meningioma Progression

Epithelial to mesenchymal transition (EMT), which is characterized by the reduced expression of E-cadherin and increased expression of N-cadherin, plays an important role in the tumor invasion and metastasis. Classical Wnt signaling pathway has a tight link with EMT and it has been shown that nuclear translocation of β-catenin can induce EMT. This research has showed that genes that are involved in cadherin switch, CDH1 and CDH2, play a role in meningioma progression. Increased N-cadherin expression in relation to E-cadherin was recorded. In meningioma, transcription factors SNAIL, SLUG, and TWIST1 demonstrated strong expression in relation to E- and N-cadherin. The expression of SNAIL and SLUG was significantly associated with higher grades (p = 0.001), indicating their role in meningioma progression. Higher grades also recorded an increased expression of total β-catenin followed by an increased expression of its active form (p = 0.000). This research brings the results of genetic and protein analyzes of important molecules that are involved in Wnt and EMT signaling pathways and reveals their role in intracranial meningioma. The results of this study offer guidelines and new markers of progression for future research and reveal new molecular targets of therapeutic interventions.

Roles of the Phosphorylation of Transcriptional Factors in Epithelial-Mesenchymal Transition

Epithelial-to-mesenchymal transition (EMT) is the first step in the development of the invasive and migratory properties of cancer metastasis. Since the transcriptional reprogramming of a number of genes occurs in EMT, the regulation of EMT transcription factors has been intensively investigated. EMT transcriptional factors are commonly classified by the direct or indirect repression of E-cadherin because one of hallmarks of EMT is the loss of E-cadherin. This facilitates the expression of genes for EMT, tumor invasion, and metastasis. The posttranslational modification of EMT transcriptional factors, such as Snail and Slug, directly regulates their functions, including their stability, nuclear localization, protein-protein interaction, and ubiquitination for the promotion or termination of EMT at the specific points. Here, we discuss how posttranslational modifications regulate gene expression in a dynamic and reversible manner by modifying upstream signaling pathways, focusing in particular on the posttranslational modifications of Snail, Slug, ZEB1, ZEB2, and TWIST1. This review demonstrates that EMT transcription factors regulate metastasis through their posttranslational modifications and that the flexibility and reversibility of EMT can be modified by phosphorylation.

Downregulation of miR‑186 promotes the proliferation and drug resistance of glioblastoma cells by targeting Twist1

Temozolomide (TMZ) is widely used as a chemotherapeutic agent in the treatment of glioma; however, the development of drug resistance remains a major obstacle in the effective treatment of glioblastoma. Increasing evidence has indicated that microRNAs (miRs) are involved in the drug resistance of glioma; however, the role of miR‑186‑5p in the TMZ resistance of glioblastoma remains unknown. In the present study, the role of miR‑186‑5p in the resistance of glioblastoma to TMZ was investigated. mRNA and protein expression levels were detected via reverse transcription‑quantitative PCR and western blot analysis, respectively. It was determined that miR‑186‑5p was significantly downregulated in glioblastoma tissues and cell lines. Additionally, the expression of miR‑186‑5p was decreased, whereas that of Twist1 was upregulated during the development of drug resistance in glioma cells. The introduction of miR‑186 into glioblastoma cells via transfection decreased the proliferation and TMZ resistance of glioblastoma cells, as determined via 5‑ethynyl‑2'‑deoxyuridine and Cell Counting Kit‑8 assays, whereas the inhibition of miR‑186‑5p induced opposing effects. Furthermore, luciferase reporter and expression rescue assays revealed that miR‑186‑5p bound to the 3'‑untranslated region of Twist‑related protein 1 (Twist1). In conclusion, the present study demonstrated that downregulation of miR‑186‑5p may contribute to the proliferation and drug resistance of glioblastoma cells via the regulation of Twist1 expression. These results suggested that miR‑186‑5p may be a novel therapeutic target in the treatment of glioblastoma.

Strong FGFR3 staining is a marker for FGFR3 fusions in diffuse gliomas

Background

Inhibitors of fibroblast growth factor receptors (FGFRs) have recently arisen as a promising treatment option for patients with FGFR alterations. Gene fusions involving FGFR3 and transforming acidic coiled-coil protein 3 (TACC3) have been detected in diffuse gliomas and other malignancies, and fusion-positive cases have responded well to FGFR inhibition. As high FGFR3 expression has been detected in fusion-positive tumors, we sought to determine the clinical significance of FGFR3 protein expression level as well as its potential for indicating FGFR3 fusions.

Methods

We performed FGFR3 immunohistochemistry on tissue microarrays containing 676 grades II-IV astrocytomas and 116 grades II-III oligodendroglial tumor specimens. Fifty-one cases were further analyzed using targeted sequencing.

Results

Moderate to strong FGFR3 staining was detected in gliomas of all grades, was more common in females, and was associated with poor survival in diffuse astrocytomas. Targeted sequencing identified FGFR3-TACC3 fusions and an FGFR3-CAMK2A fusion in 10 of 15 strongly stained cases, whereas no fusions were found in 36 negatively to moderately stained cases. Fusion-positive cases were predominantly female and negative for IDH and EGFR/PDGFRA/MET alterations. These and moderately stained cases show lower MIB-1 proliferation index than negatively to weakly stained cases. Furthermore, stronger FGFR3 expression was commonly observed in malignant tissue regions of lower cellularity in fusion-negative cases. Importantly, subregional negative FGFR3 staining was also observed in a few fusion-positive cases.

Conclusions

Strong FGFR3 protein expression is indicative of FGFR3 fusions and may serve as a clinically applicable predictive marker for treatment regimens based on FGFR inhibitors.

Elevated expression of hyaluronan synthase 2 associates with decreased survival in diffusely infiltrating astrocytomas

Background

Diffusely infiltrating astrocytomas originate from astrocytic glial cells or their precursor cells and are the most common type of brain tumors in adults. In this retrospective study, we investigated the content of hyaluronan, its cell surface receptor, CD44 and the expression of hyaluronan metabolizing enzymes, in these aggressive tumors. Hyaluronan is the main component of extracellular matrix in the brain. In many tumors, aberrant hyaluronan metabolism implicates aggressive disease progression and metastatic potential.

Methods

Our material consisted of 163 diffusely infiltrating astrocytomas (WHO grades II-IV). Tumor samples were processed into tissue microarray (TMA) blocks. The TMA sections were stained for hyaluronan, CD44, hyaluronan synthases 1–3 (HAS1–3) and hyaluronidase 2 (HYAL2). The immunostaining results were compared with χ2 –test or with Kruskal-Wallis test for correlation with clinicopathological parameters and survival analyses were done with Kaplan-Meier log rank test and Cox regression.

Results

Hyaluronan and CD44 were strongly expressed in astrocytic gliomas but their expression did not correlate with WHO grade or any other clinicopathological parameters whereas high HAS2 staining intensity was observed in IDH1 negative tumors (p = 0.003). In addition, in non-parametric tests increased HAS2 staining intensity correlated with increased cell proliferation (p = 0.013) and in log rank test with decreased overall survival of patients (p = 0.001). In the Cox regression analysis HAS2 expression turned out to be a significant independent prognostic factor (p = 0.008).

Conclusions

This study indicates that elevated expression of HAS2 is associated with glioma progression and suggests that HAS2 has a prognostic significance in diffusely infiltrating astrocytomas.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4569-1) contains supplementary material, which is available to authorized users.

Targeting TWIST1 through loss of function inhibits tumorigenicity of human glioblastoma

TWIST1 (TW) is a bHLH transcription factor (TF) and master regulator of the epithelial-to-mesenchymal transition (EMT). In vitro, TW promotes mesenchymal change, invasion, and self-renewal in glioblastoma (GBM) cells. However, the potential therapeutic relevance of TW has not been established through loss-of-function studies in human GBM cell xenograft models. The effects of TW loss of function (gene editing and knockdown) on inhibition of tumorigenicity of U87MG and GBM4 glioma stem cells were tested in orthotopic xenograft models and conditional knockdown in established flank xenograft tumors. RNAseq and the analysis of tumors investigated putative TW-associated mechanisms. Multiple bioinformatic tools revealed significant alteration of ECM, membrane receptors, signaling transduction kinases, and cytoskeleton dynamics leading to identification of PI3K/AKT signaling. We experimentally show alteration of AKT activity and periostin (POSTN) expression in vivo and/or in vitro. For the first time, we show that effect of TW knockout inhibits AKT activity in U87MG cells in vivo independent of PTEN mutation. The clinical relevance of TW and candidate mechanisms was established by analysis of the TCGA and ENCODE databases. TW expression was associated with decreased patient survival and LASSO regression analysis identified POSTN as one of top targets of TW in human GBM. While we previously demonstrated the role of TW in promoting EMT and invasion of glioma cells, these studies provide direct experimental evidence supporting protumorigenic role of TW independent of invasion in vivo and the therapeutic relevance of targeting TW in human GBM. Further, the role of TW driving POSTN expression and AKT signaling suggests actionable targets, which could be leveraged to mitigate the oncogenic effects of TW in GBM.

AKT-ions with a TWIST between EMT and MET

The transcription factor Twist is an important regulator of cranial suture during embryogenesis. Closure of the neural tube is achieved via Twist-triggered cellular transition from an epithelial to mesenchymal phenotype, a process known as epithelial-mesenchymal transition (EMT), characterized by a remarkable increase in cell motility. In the absence of Twist activity, EMT and associated phenotypic changes in cell morphology and motility can also be induced, albeit moderately, by other transcription factor families, including Snail and Zeb. Aberrant EMT triggered by Twist in human mammary tumour cells was first reported to drive metastasis to the lung in a metastatic breast cancer model. Subsequent analysis of many types of carcinoma demonstrated overexpression of these unique EMT transcription factors, which statistically correlated with worse outcome, indicating their potential as biomarkers in the clinic. However, the mechanisms underlying their activation remain unclear. Interestingly, increasing evidence indicates they are selectively activated by distinct intracellular kinases, thereby acting as downstream effectors facilitating transduction of cytoplasmic signals into nucleus and reprogramming EMT and mesenchymal-epithelial transition (MET) transcription to control cell plasticity. Understanding these relationships and emerging data indicating differential phosphorylation of Twist leads to complex and even paradoxical functionalities, will be vital to unlocking their potential in clinical settings.

Signaling pathways and mesenchymal transition in pediatric high-grade glioma

Pediatric high-grade gliomas (pHGG), including diffuse intrinsic pontine gliomas (DIPG), are the most lethal types of cancer in children. In recent years, it has become evident that these tumors are driven by epigenetic events, mainly mutations involving genes encoding Histone 3, setting them apart from their adult counterparts. These tumors are exceptionally resistant to chemotherapy and respond only temporarily to radiotherapy. Moreover, their delicate location and diffuse growth pattern make complete surgical resection impossible. In many other forms of cancer, chemo- and radioresistance, in combination with a diffuse, invasive phenotype, are associated with a transcriptional program termed the epithelial-to-mesenchymal transition (EMT). Activation of this program allows cancer cells to survive individually, invade surrounding tissues and metastasize. It also enables them to survive exposure to cytotoxic therapy, including chemotherapeutic drugs and radiation. We here suggest that EMT plays an important, yet poorly understood role in the biology and therapy resistance of pHGG and DIPG. This review summarizes the current knowledge on the major signal transduction pathways and transcription factors involved in the epithelial-to-mesenchymal transition in cancer in general and in pediatric HGG and DIPG in particular. Despite the fact that the mesenchymal transition has not yet been specifically studied in pHGG and DIPG, activation of pathways and high levels of transcription factors involved in EMT have been described. We conclude that the mesenchymal transition is likely to be an important element of the biology of pHGG and DIPG and warrants further investigation for the development of novel therapeutics.

Prognostic Significance of Zinc Finger E-Box-Binding Homeobox Family in Glioblastoma

Background

Epithelial-mesenchymal transition (EMT) is an essential progress for tumor cell invasion to both epithelial and non-epithelial cancers, and zinc finger E-box-binding homeobox 1/2 (ZEB1/2) is a well-known promoter of EMT. In glioma cell lines, both ZEB1 and ZEB2 have been demonstrated to facilitate cancer cell proliferation and invasion with experiments in vitro. However, the clinical significance of ZEB1 and ZEB2 in glioblastoma (GBM) is still controversial.

Material/Methods

We detected the expression of ZEB1 and ZEB2 in 91 cases of GBM with immunohistochemistry and investigated the correlation between clinicopathological factors and ZEB family expression with Fisher test. By univariate analysis with Kaplan-Meier test, we explored the prognostic significance of ZEB1/2 expression and the clinicopathological factors in GBM. By multivariate analysis with the Cox regression model, we identified the independent prognostic factors in GBM.

Results

The percentages of ZEB1 high expression and ZEB2 high expression were 31.9% (29/91) and 41.9% (36/91), respectively. High expression of ZEB2 was significantly associated with lower survival rate of GBM patients (P=0.001). ZEB2, lower KPS score (P=0.004), gross total resection (P<0.001) and higher Ki67 percentage (P=0.001) were notably correlated to worse prognosis of GBM. With multivariate analysis, high expression of ZEB2 was demonstrated to be an independent prognostic factor indicating unfavorable prognosis of GBM (P=0.001, HR=3.86, and 95%CI=1.61–9.23).

Conclusions

High expression of ZEB2 is an independent prognostic factor predicting unfavorable prognosis of GBM, indicating that ZEB2 or its downstream proteins may be potential drug targets of GBM therapy.

The Role of Hypoxia in Glioblastoma Invasion

Glioblastoma multiforme (GBM), a grade IV astrocytoma, is the most common and deadly type of primary malignant brain tumor, with a patient's median survival rate ranging from 15 to 17 months. The current treatment for GBM involves tumor resection surgery based on MRI image analysis, followed by radiotherapy and treatment with temozolomide. However, the gradual development of tumor resistance to temozolomide is frequent in GBM patients leading to subsequent tumor regrowth/relapse. For this reason, the development of more effective therapeutic approaches for GBM is of critical importance. Low tumor oxygenation, also known as hypoxia, constitutes a major concern for GBM patients, since it promotes cancer cell spreading (invasion) into the healthy brain tissue in order to evade this adverse microenvironment. Tumor invasion not only constitutes a major obstacle to surgery, radiotherapy, and chemotherapy, but it is also the main cause of death in GBM patients. Understanding how hypoxia triggers the GBM cells to become invasive is paramount to developing novel and more effective therapies against this devastating disease. In this review, we will present a comprehensive examination of the available literature focused on investigating how GBM hypoxia triggers an invasive cancer cell phenotype and the role of these invasive proteins in GBM progression.

Is there a role for epithelial-mesenchymal transition in adrenocortical tumors?

PURPOSE

Epithelial-mesenchymal transition (EMT) is a biological dynamic process by which epithelial cells lose their epithelial phenotype and acquire mesenchymal invasive and migratory characteristics. This has been postulated as an essential step during cancer progression and metastasis. Although this is well described in other tumors, the role of EMT in adrenocortical tumors (ACT) has yet to be addressed.

METHODS

The aim of this study was to evaluate the expression of EMT markers e-cadherin, vimentin, and fibronectin, along with EMT-transcription factors (EMT-TFs), TWIST1, SIP1, and SNAIL in 24 adrenocortical carcinoma (ACC), 19 adrenocortical adenomas (ACA), 27 childhood-onset adrenocortical tumors (CAT), and 12 normal adrenal glands. The association of EMT and EMT-TFs with clinical outcomes and pathology features were also evaluated.

RESULTS

Cytoplasmic vimentin expression was increased among CAT samples when compared to ACC, ACA, and normal adrenal samples (p < 0.001). There was no difference in e-cadherin and fibronectin expression observed between groups. Nuclear and cytoplasmic expression of TWIST1 and SIP1 was stronger in CAT and ACC vs. ACA and normal tissue samples (all, p < 0.05). ACT, regardless of classification, exhibited increased SNAIL expression when compared to normal tissue (p < 0.05). A significant correlation was observed between vimentin and TWIST1 (r _s = 0.44, p < 0.001); SIP1 (r _s = 0.51, p < 0.001); and SNAIL (r _s = 0.23, p < 0.05). TWIST1 and SIP1 expressions demonstrated a significant correlation (r _s = 0.56, p < 0.001). High SIP1 expression was associated with a lower survival rate among ACC cases (p < 0.05).

CONCLUSIONS

Vimentin, TWIST1, and SIP1 expressions are increased in aggressive ACT. Therefore, EMT may play a relevant role in adrenal tumorigenesis.

Cellular heterogeneity contributes to subtype-specific expression of ZEB1 in human glioblastoma

The transcription factor ZEB1 has gained attention in tumor biology of epithelial cancers because of its function in epithelial-mesenchymal transition, DNA repair, stem cell biology and tumor-induced immunosuppression, but its role in gliomas with respect to invasion and prognostic value is controversial. We characterized ZEB1 expression at single cell level in 266 primary brain tumors and present a comprehensive dataset of high grade gliomas with Ki67, p53, IDH1, and EGFR immunohistochemistry, as well as EGFR FISH. ZEB1 protein expression in glioma stem cell lines was compared to their parental tumors with respect to gene expression subtypes based on RNA-seq transcriptomic profiles. ZEB1 is widely expressed in glial tumors, but in a highly variable fraction of cells. In glioblastoma, ZEB1 labeling index is higher in tumors with EGFR amplification or IDH1 mutation. Co-labeling studies showed that tumor cells and reactive astroglia, but not immune cells contribute to the ZEB1 positive population. In contrast, glioma cell lines constitutively express ZEB1 irrespective of gene expression subtype. In conclusion, our data indicate that immune infiltration likely contributes to differential labelling of ZEB1 and confounds interpretation of bulk ZEB1 expression data.

MicroRNA-361-5p inhibits epithelial-to-mesenchymal transition of glioma cells through targeting Twist1

MicroRNA-361-5p (miR-361-5p) has been reported to be dysregulated in various human cancer types. However, the function of miR-361-5p in glioma remains unknown. In the present study, we aimed to investigate the biological functions of miR-361-5p in regulating glioma progression and the underlying molecular mechanism. We found that miR-361-5p was significantly decreased in glioma tissues and cell lines as detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis. Functional analysis revealed that miR-361-5p overexpression significantly inhibited glioma cell migration, invasion and epithelial-mesenchymal transition (EMT) whereas suppression of miR-361-5p showed opposite effects. Bioinformatic analysis showed that Twist1, a critical EMT inducer, was a predicted target of miR-361-5p which was validated by dual-luciferase reporter assay, RT-qPCR and western blot analysis. Further analysis indicated that miR-361-5p regulates the Twist1/Bmi-1 signaling axis. Rescue experiments showed that restoration of Twist1 expression significantly reversed the suppressive effect of miR-361-5p on cell migration, invasion and EMT. Taken together, the present study demonstrated an important role of miR-361-5p in glioma - which regulated the EMT of glioma cells by targeting and regulating Twist1. These findings provide novel insight into understanding the role and mechanism of miR-361-5p in regulating the biolo-gical behavior of glioma cells and suggest that miR-361-5p is a novel potential therapeutic target for glioma.

Patients treatment with neuroglioma by teniposide and semustine and its influence on Twist and E-cadherin expression

This study focuses on curative effects of teniposide combining with semustine on patients with neuroglioma and the influences on the expression of Twist and E-cadherin in tissue. Sixty-eight patients with neuroglioma taking operation in our hospital were divided into two groups randomly. Single radiotherapy was given to 34 patients in group A, and teniposide (VM-26) and semustine (Me-CCUN) were added to radiotherapy for 34 patients in group B. Then, curative effects, survival rate, living quality and adverse reaction rate after operation were compared between two groups. Moreover, the difference in positive expression rate of Twist and E-cadherin before and after treatment between two groups was analyzed by immunohistochemistry. Results: In group B, the effective rate of treatment was 88.2%, and the disease control rate was 70.6%, higher than 52.9% and 32.4% in group A with statistical significance (P < 0.05). Moreover, the survival rate in three years of group B was 44.1%, and the score of living quality was 67.11 ± 4.32, and also higher than 23.5% and 63.79 ± 4.53 in group A with statistical significance (P < 0.05). However, the difference between two groups in adverse reaction rate has no statistical significance (P > 0.05). In addition, the difference in positive expression rate of Twist and E-cadherin between group A and group B has no statistical significance before treatment (P > 0.05). After treatment, however, the positive rate of Twist in group B is lower than that in group A, while the positive rate of E-cadherin is higher. Both differences have statistical significance (P < 0.05). Chemotherapy of VM-26 combining with Me-CCNU can inhibit Twist expression and improve the expression rate of E-cadherin to help improving the curative effects and living quality and increasing survival rate.