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

CIRCVMA21-RELATED PATHWAY ALLEVIATES LIPOPOLYSACCHARIDE-INDUCED HK-2 CELL INJURY

ABSTRACT

Background : It is reported that circVMA21 has an inhibition effect on sepsis-induced acute kidney injury (AKI). Therefore, the underlying molecular mechanisms of circVMA21 in AKI are worthy of further investigation. Material and Methods : Lipopolysaccharide (LPS) was used to induce HK2 cell injury. CircVMA21, miR-337-3p and ZEB2 expression was tested by qRT-PCR. Cell growth was detected by CCK8 assay, EdU assay, and flow cytometry. Protein levels were examined by western blot. The levels of inflammatory factors and oxidative stress markers were measured to evaluate cell inflammatory response and oxidative stress. RNA relationship as verified by dual-luciferase reporter assay, RIP assay, and RNA pull-down assay. Results : CircVMA21 had decreased expression in AKI patients. Overexpressed circVMA21 alleviated LPS-induced HK2 cell inflammation, apoptosis, and oxidative stress. Moreover, circVMA21 sponged miR-337-3p, and miR-337-3p targeted ZEB2. The inhibitory effect of circVMA21 on LPS-induced HK2 cell injury was reversed by miR-337-3p overexpression, and ZEB2 overexpression abolished the promotion effect of miR-337-3p on LPS-induced HK2 cell injury. Conclusions : CircVMA21 could inhibit LPS-induced HK2 cell injury via miR-337-3p/ZEB2 axis.

Interleukin-17 receptor D is a favorable biomarker of glioblastoma

BACKGROUND

Glioblastoma (GBM) is the most frequent glioma in adults. The prognosis of GBM is very poor and new prognostic biomarkers are in urgent need to better select high-risk patients and guide the individual treatments.

METHODS

In our study, we compared the expression of interleukin-17 receptor D (IL17RD) between GBMs and normal tissues from TCGA database, and detected IL17RD mRNA in 17 fresh GBM pairs with qPCR. With immunohistochemistry, we investigated the expression of IL17RD in 156 GBM tissues and further evaluated its clinical significance. The associations between IL17RD and clinicopathological factors were assessed by Chi-square test. The prognostic significance of IL17RD was evaluated by univariate analysis with Kaplan-Meier method, and by multivariate analysis with Cox-regression Hazard model.

RESULTS

The TPMs and mRNAs of IL17RD in GBM were substantially lower than those in normal brain tissues. The rates of low or high expression of IL17RD accounted for 41.67% and 58.33% respectively. IL17RD was significantly associated with higher survival rates of GBM. The 3-year overall survival rates of patients with low and high IL17RD were 7.2% and 19.5% respectively. In the Cox-regression model, the IL17RD expression was defined as an independent prognostic biomarker of GBM. Patients with high IL17RD expression had a more favorable outcome than those with low IL17RD.

CONCLUSIONS

High IL17RD expression was an independent prognostic indicator of GBM, suggesting a more favorable prognosis. Our results suggested that IL17RD detection may help find the high-risk patients which may receive more severe surveillance and more individual treatments.

Zinc Finger E-Box Binding Homeobox Family: Non-Coding RNA and Epigenetic Regulation in Gliomas

Gliomas are the most common malignant brain tumours. Among them, glioblastoma (GBM) is a grade four tumour with a median survival of approximately 15 months and still limited treatment options. Although a classical epithelial to mesenchymal transition (EMT) is not the case in glioma due to its non-epithelial origin, the EMT-like processes may contribute largely to the aggressive and highly infiltrative nature of these tumours, thus promoting invasive phenotype and intracranial metastasis. To date, many well-known EMT transcription factors (EMT-TFs) have been described with clear, biological functions in glioma progression. Among them, EMT-related families of molecules such as SNAI, TWIST and ZEB are widely cited, well-established oncogenes considering both epithelial and non-epithelial tumours. In this review, we aimed to summarise the current knowledge with a regard to functional experiments considering the impact of miRNA and lncRNA as well as other epigenetic modifications, with a main focus on ZEB1 and ZEB2 in gliomas. Although we explored various molecular interactions and pathophysiological processes, such as cancer stem cell phenotype, hypoxia-induced EMT, tumour microenvironment and TMZ-resistant tumour cells, there is still a pressing need to elucidate the molecular mechanisms by which EMT-TFs are regulated in gliomas, which will enable researchers to uncover novel therapeutic targets as well as improve patients' diagnosis and prognostication.

Histone H3.3 K27M chromatin functions implicate a network of neurodevelopmental factors including ASCL1 and NEUROD1 in DIPG

Background

The histone variant H3.3 K27M mutation is a defining characteristic of diffuse intrinsic pontine glioma (DIPG)/diffuse midline glioma (DMG). This histone mutation is responsible for major alterations to histone H3 post-translational modification (PTMs) and subsequent aberrant gene expression. However, much less is known about the effect this mutation has on chromatin structure and function, including open versus closed chromatin regions as well as their transcriptomic consequences.

Results

Recently, we developed isogenic CRISPR-edited DIPG cell lines that are wild-type for histone H3.3 that can be compared to their matched K27M lines. Here we show via ATAC-seq analysis that H3.3K27M glioma cells have unique accessible chromatin at regions corresponding to neurogenesis, NOTCH, and neuronal development pathways and associated genes that are overexpressed in H3.3K27M compared to our isogenic wild-type cell line. As to mechanisms, accessible enhancers and super-enhancers corresponding to increased gene expression in H3.3K27M cells were also mapped to genes involved in neurogenesis and NOTCH signaling, suggesting that these pathways are key to DIPG tumor maintenance. Motif analysis implicates specific transcription factors as central to the neuro-oncogenic K27M signaling pathway, in particular, ASCL1 and NEUROD1.

Conclusions

Altogether our findings indicate that H3.3K27M causes chromatin to take on a more accessible configuration at key regulatory regions for NOTCH and neurogenesis genes resulting in increased oncogenic gene expression, which is at least partially reversible upon editing K27M back to wild-type.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13072-022-00447-6.

miR-637 Prevents Glioblastoma Progression by Interrupting ZEB2/WNT/β-catenin Cascades

Glioblastomas (GBMs) are the most frequent primary malignancies in the central nervous system. Aberrant activation of WNT/β-catenin signaling pathways is critical for GBM malignancy. However, the regulation of WNT/β-catenin signaling cascades remains unclear. Presently, we observed the increased expression of ZEB2 and the decreased expression of miR-637 in GBM. The expression of miR-637 was negatively correlated with ZEB2 expression. miR-637 overexpression overcame the ZEB2-enhanced cell proliferation and G1/S phase transition. Besides, miR-637 suppressed the canonical WNT/β-catenin pathways by targeting WNT7A directly. Gain- and loss-of-function experiments with U251 mice demonstrated that miR-637 inhibited cell proliferation and arrested the G1/S phase transition, leading to tumor growth suppression. The collective findings suggest that ZEB2 and WNT/β-catenin cascades merge at miR-637, and the ectopic expression of miR-637 disturbs ZEB2/WNT/β-catenin-mediated GBM growth. The findings provide new clues for improving β-catenin-targeted therapy against GBM.

ZEB2 Knock-down Induces Apoptosis in Human Myeloid Leukemia HL-60 Cells

INTRODUCTION

Acute myeloid leukemia (AML) is the most prevalent type of cancer in the adult hematopoietic system. Conventional therapies are associated with unfavorable side effects in individuals diagnosed with AML. These after-effects with partial remission reflect the urgent need for novel therapeutic approaches for inducing apoptosis, specifically in malignant cells, without affecting other cells. As a transcription factor (TF), ZEB2 (Zinc Finger E-Box Binding Homeobox 2) regulates the expression of specific genes in normal conditions. However, increased expression of ZEB2 is reported in various cancers, especially in AML, which is related to a higher degree of apoptosis inhibition of malignant cells. In this work, the role of ZEB2 in apoptosis inhibition is surveyed through ZEB2 specific knocking-down in human myeloid leukemia HL-60 cells.

MATERIALS AND METHODS

Transfection of HL-60 cells was conducted using ZEB2-siRNA at concentrations of 20, 40, 60, and 80 pmol within 24, 48, and 72 h. After determining the optimum dose and time, flow cytometry was used to measure the apoptosis rate. The MTT assay was also utilized to evaluate the cytotoxic impact of transfection on the cells. The expression of candidate genes was measured before and after transfection using qRT-PCR.

RESULTS

According to obtained results, suppression of ZEB2 expression through siRNA was associated with the induction of apoptosis, increased pro-apoptotic, and decreased anti-apoptotic gene expression. Transfection of ZEB2-siRNA was also associated with reduced cell proliferation and viability.

CONCLUSION

Our study results suggest that ZEB2 suppression in myeloid leukemia cells through apoptosis induction could be a proper therapeutic method.

Silencing ZEB2 Induces Apoptosis and Reduces Viability in Glioblastoma Cell Lines

Background: Glioma is an aggressive type of brain tumor that originated from neuroglia cells, accounts for about 80% of all malignant brain tumors. Glioma aggressiveness has been associated with extreme cell proliferation, invasion of malignant cells, and resistance to chemotherapies. Due to resistance to common therapies, glioma affected patients’ survival has not been remarkably improved. ZEB2 (SIP1) is a critical transcriptional regulator with various functions during embryonic development and wound healing that has abnormal expression in different malignancies, including brain tumors. ZEB2 overexpression in brain tumors is attributed to an unfavorable state of the malignancy. Therefore, we aimed to investigate some functions of ZEB2 in two different glioblastoma U87 and U373 cell lines. Methods: In this study, we investigated the effect of ZEB2 knocking down on the apoptosis, cell cycle, cytotoxicity, scratch test of the two malignant brain tumor cell lines U87 and U373. Besides, we investigated possible proteins and microRNA, SMAD2, SMAD5, and miR-214, which interact with ZEB2 via in situ analysis. Then we evaluated candidate gene expression after ZEB2-specific knocking down. Results: We found that ZEB2 suppression induced apoptosis in U87 and U373 cell lines. Besides, it had cytotoxic effects on both cell lines and reduced cell migration. Cell cycle analysis showed cell cycle arrest in G0/G1 and apoptosis induction in U87 and U373 cell lines receptively. Also, we have found that SAMAD2/5 expression was reduced after ZEB2-siRNA transfection and miR-214 upregulated after transfection. Conclusions: In line with previous investigations, our results indicated a critical oncogenic role for ZEB2 overexpression in brain glioma tumors. These properties make ZEB2 an essential molecule for further studies in the treatment of glioma cancer.

MicroRNA-140 Represses Esophageal Cancer Progression via Targeting ZEB2 to Regulate Wnt/β-Catenin Pathway

BACKGROUND

MicroRNAs have been reported to play regulatory functions in various cancers, including esophageal cancer. The aim of this study was to investigate the effects of miR-140 on the progression of esophageal cancer and the underlying regulatory mechanism.

METHODS

The levels of miR-140 and zinc finger E-box-binding homeobox 2 (ZEB2) messenger RNA in esophageal cancer tissues and cell lines were measured by quantitative real-time polymerase chain reaction. The protein levels of ZEB2, β-catenin, c-Myc, and cyclinD1 were determined by Western blot. Cell proliferation and apoptosis were determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay and flow cytometry, respectively. Cell migration and invasion were assessed by transwell assay. In addition, the relationship between miR-140 and ZEB2 was predicted by TargetScan online database and confirmed by dual-luciferase reporter assay. The tumor xenograft model was used to verify the role of miR-140 in esophageal cancer progression in vivo.

RESULTS

The expression of miR-140 was downregulated whereas ZEB2 expression was upregulated in esophageal cancer tissues compared with paracancerous normal tissues. Functionally, both miR-140 overexpression and ZEB2 knockdown inhibited proliferation, migration, and invasion and induced apoptosis in esophageal cancer cells. ZEB2 overexpression reversed the effects of miR-140 on proliferation, apoptosis, migration, and invasion of esophageal cancer cells. Mechanistically, ZEB2 was identified as a target of miR-140. Furthermore, miR-140 suppressed Wnt/β-catenin pathway by regulating ZEB2 expression in esophageal cancer cells. MiR-140 inhibited tumor growth of esophageal cancer through repressing ZEB2 expression in vivo.

CONCLUSIONS

Our results demonstrated that miR-140 inhibited esophageal cancer development by targeting ZEB2 through inactivating Wnt/β-catenin pathway.

Expression of GLUT1 in Pseudopalisaded and Perivascular Tumor Cells Is an Independent Prognostic Factor for Patients With Glioblastomas

Glioblastomas are highly aggressive brain tumors with a particularly poor prognosis. Glucose transporter-1 (GLUT1/SLC2A1), a uniporter that is expressed by various carcinomas and may be involved in malignant neoplasm glycometabolism, may also be related to prognosis in glioblastomas. GLUT1 is essential to central nervous system glycometabolism. To clarify the exact role of GLUT1 in glioblastoma, we assessed the expression and localization of GLUT1 in patient samples by immunohistochemistry and in situ RNA hybridization. This revealed that GLUT1 was mainly expressed on perivascular and pseudopalisaded tumor cell membranes. All samples expressed GLUT1 to some degree, with 30.8% showing stronger staining. On the basis of these data, samples were divided into high and low expression groups, although SLC2A1 mRNA expression was also higher in the high GLUT1 expression group. Kaplan-Meier survival curves revealed that high GLUT1 expression associated with lower overall survival (log-rank test, p = 0.001) and worse patient prognoses (p = 0.001). Finally, MIB-1 staining was stronger in high GLUT1 expression samples (p = 0.0004), suggesting a link with proliferation. We therefore hypothesize that GLUT1 expression in glioblastomas may enhance glycolysis, affecting patient prognosis. Examination of GLUT1 in patients with glioblastomas may provide a new prognostic tool to improve outcome.

ROS and oncogenesis with special reference to EMT and stemness

Elevation of the level of intracellular reactive oxygen species (ROS) has immense implication in the biological system. On the one hand, ROS promote the signaling cascades for the maintenance of normal physiological functions, the phenomenon referred to as redox biology, and on the other hand increased ROS can cause damages to the cellular macromolecules as well as genetic material, the process known as oxidative stress. Oxidative stress acts as an etiological factor for wide varieties of pathologies, cancer being one of them. ROS is regarded as a "double-edged sword" with respect to oncogenesis. It can suppress as well as promote the malignant progression depending on the type of signaling pathway it uses. Moreover, the attribution of ROS in promoting phenotypic plasticity as well as acquisition of stemness during neoplasia has become a wide area of research. The current review discussed all the aspects of ROS in the perspective of tumor biology with special reference to epithelial-mesenchymal transition (EMT) and cancer stem cells.

MicroRNA‑30a regulates cell proliferation, migration, invasion and apoptosis in human nasopharyngeal carcinoma via targeted regulation of ZEB2

MicroRNA-30a (miR-30a) was previously reported to serve as a tumor suppressor able to inhibit the development and progression of certain types of cancer. A number of previous studies demonstrated that zinc finger E-box binding homeobox 2 (ZEB2) may be regulated by miR-30a in clear cell renal cell carcinoma and breast cancer. However, the function of miR-30a in human nasopharyngeal carcinoma (NPC) remains unclear. The present study aimed to investigate the association between miR-30a and ZEB2 in NPC. Therefore, the expression levels of miR-30a and ZEB2 were measured in human NPC cells and tissues from patients with NPC, and the present results suggested that the expression level of miR-30a was significantly decreased in NPC tissues compared with paracancerous tissues. The direct interaction between miR-30a and the untranslated region of ZEB2 was examined using the dual-luciferase reporter assay, and ZEB2 was identified as a direct target of miR-30a. Additionally, the effects of miR-30a and ZEB2 overexpression on cell proliferation, migration, invasion and apoptosis were additionally investigated. Functional experiments identified that overexpression of miR-30a increased apoptosis and suppressed cell proliferation, cell migration and cell invasion by directly targeting ZEB2. Collectively, the present study suggested that miR-30a may serve an important role in the progression of NPC and may represent a novel target for the treatment of patients with NPC.

Comparison and analysis of lncRNA-mediated ceRNA regulation in different molecular subtypes of glioblastoma

LncRNA-mediated ceRNA regulation varies among different molecular subtypes in glioblastoma.