miR-23a promotes invasion of glioblastoma via HOXD10-regulated glial-mesenchymal transition

The HOX Gene Family's Role as Prognostic and Diagnostic Biomarkers in Hematological and Solid Tumors

The HOX gene family encodes for regulatory transcription factors that play a crucial role in embryogenesis and differentiation of adult cells. This highly conserved family of genes consists of thirty-nine genes in humans that are located in four clusters, A-D, on different chromosomes. While early studies on the HOX gene family have been focused on embryonic development and its related disorders, research has shifted to examine aberrant expression of HOX genes and the subsequent implication in cancer prediction and progression. Due to their role of encoding master regulatory transcription factors, the abnormal expression of HOX genes has been shown to affect all stages of tumorigenesis and metastasis. This review highlights the novel role of the HOX family's clinical relevance as both prognostic and diagnostic biomarkers in hematological and solid tumors.

Single-cell multi-omics sequencing uncovers region-specific plasticity of glioblastoma for complementary therapeutic targeting

Glioblastoma (GBM) cells are highly heterogeneous and invasive, leading to treatment resistance and relapse. However, the molecular regulation in and distal to tumors remains elusive. Here, we collected paired tissues from the tumor core (TC) and peritumoral brain (PTB) for integrated snRNA-seq and snATAC-seq analyses. Tumor cells infiltrating PTB from TC behave more like oligodendrocyte progenitor cells than astrocytes at the transcriptome level. Dual-omics analyses further suggest that the distal regulatory regions in the tumor genome and specific transcription factors are potential determinants of regional heterogeneity. Notably, while activator protein 1 (AP-1) is active in all GBM states, its activity declines from TC to PTB, with another transcription factor, BACH1, showing the opposite trend. Combined inhibition of AP-1 and BACH1 more efficiently attenuates the tumor progression in mice and prolongs survival than either single-target treatment. Together, our work reveals marked molecular alterations of infiltrated GBM cells and a synergy of combination therapy targeting intratumor heterogeneity in and distal to GBM.

Circulating Liquid Biopsy Biomarkers in Glioblastoma: Advances and Challenges

Gliomas, particularly glioblastoma (GBM), represent the most prevalent and aggressive tumors of the central nervous system (CNS). Despite recent treatment advancements, patient survival rates remain low. The diagnosis of GBM traditionally relies on neuroimaging methods such as magnetic resonance imaging (MRI) or computed tomography (CT) scans and postoperative confirmation via histopathological and molecular analysis. Imaging techniques struggle to differentiate between tumor progression and treatment-related changes, leading to potential misinterpretation and treatment delays. Similarly, tissue biopsies, while informative, are invasive and not suitable for monitoring ongoing treatments. These challenges have led to the emergence of liquid biopsy, particularly through blood samples, as a promising alternative for GBM diagnosis and monitoring. Presently, blood and cerebrospinal fluid (CSF) sampling offers a minimally invasive means of obtaining tumor-related information to guide therapy. The idea that blood or any biofluid tests can be used to screen many cancer types has huge potential. Tumors release various components into the bloodstream or other biofluids, including cell-free nucleic acids such as microRNAs (miRNAs), circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), proteins, extracellular vesicles (EVs) or exosomes, metabolites, and other factors. These factors have been shown to cross the blood-brain barrier (BBB), presenting an opportunity for the minimally invasive monitoring of GBM as well as for the real-time assessment of distinct genetic, epigenetic, transcriptomic, proteomic, and metabolomic changes associated with brain tumors. Despite their potential, the clinical utility of liquid biopsy-based circulating biomarkers is somewhat constrained by limitations such as the absence of standardized methodologies for blood or CSF collection, analyte extraction, analysis methods, and small cohort sizes. Additionally, tissue biopsies offer more precise insights into tumor morphology and the microenvironment. Therefore, the objective of a liquid biopsy should be to complement and enhance the diagnostic accuracy and monitoring of GBM patients by providing additional information alongside traditional tissue biopsies. Moreover, utilizing a combination of diverse biomarker types may enhance clinical effectiveness compared to solely relying on one biomarker category, potentially improving diagnostic sensitivity and specificity and addressing some of the existing limitations associated with liquid biomarkers for GBM. This review presents an overview of the latest research on circulating biomarkers found in GBM blood or CSF samples, discusses their potential as diagnostic, predictive, and prognostic indicators, and discusses associated challenges and future perspectives.

Comprehensive understanding of glioblastoma molecular phenotypes: classification, characteristics, and transition

Among central nervous system-associated malignancies, glioblastoma (GBM) is the most common and has the highest mortality rate. The high heterogeneity of GBM cell types and the complex tumor microenvironment frequently lead to tumor recurrence and sudden relapse in patients treated with temozolomide. In precision medicine, research on GBM treatment is increasingly focusing on molecular subtyping to precisely characterize the cellular and molecular heterogeneity, as well as the refractory nature of GBM toward therapy. Deep understanding of the different molecular expression patterns of GBM subtypes is critical. Researchers have recently proposed tetra fractional or tripartite methods for detecting GBM molecular subtypes. The various molecular subtypes of GBM show significant differences in gene expression patterns and biological behaviors. These subtypes also exhibit high plasticity in their regulatory pathways, oncogene expression, tumor microenvironment alterations, and differential responses to standard therapy. Herein, we summarize the current molecular typing scheme of GBM and the major molecular/genetic characteristics of each subtype. Furthermore, we review the mesenchymal transition mechanisms of GBM under various regulators.

Extracellular vesicles secreted by 3D tumor organoids are enriched for immune regulatory signaling biomolecules compared to conventional 2D glioblastoma cell systems

Background

Newer 3D culturing approaches are a promising way to better mimic the in vivo tumor microenvironment and to study the interactions between the heterogeneous cell populations of glioblastoma multiforme. Like many other tumors, glioblastoma uses extracellular vesicles as an intercellular communication system to prepare surrounding tissue for invasive tumor growth. However, little is known about the effects of 3D culture on extracellular vesicles. The aim of this study was to comprehensively characterize extracellular vesicles in 3D organoid models and compare them to conventional 2D cell culture systems.

Methods

Primary glioblastoma cells were cultured as 2D and 3D organoid models. Extracellular vesicles were obtained by precipitation and immunoaffinity, with the latter allowing targeted isolation of the CD9/CD63/CD81 vesicle subpopulation. Comprehensive vesicle characterization was performed and miRNA expression profiles were generated by smallRNA-sequencing. In silico analysis of differentially regulated miRNAs was performed to identify mRNA targets and corresponding signaling pathways. The tumor cell media and extracellular vesicle proteome were analyzed by high-resolution mass spectrometry.

Results

We observed an increased concentration of extracellular vesicles in 3D organoid cultures. Differential gene expression analysis further revealed the regulation of twelve miRNAs in 3D tumor organoid cultures (with nine miRNAs down and three miRNAs upregulated). MiR-23a-3p, known to be involved in glioblastoma invasion, was significantly increased in 3D. MiR-7-5p, which counteracts glioblastoma malignancy, was significantly decreased. Moreover, we identified four miRNAs (miR-323a-3p, miR-382-5p, miR-370-3p, miR-134-5p) located within the DLK1-DIO3 domain, a cancer-associated genomic region, suggesting a possible importance of this region in glioblastoma progression. Overrepresentation analysis identified alterations of extracellular vesicle cargo in 3D organoids, including representation of several miRNA targets and proteins primarily implicated in the immune response.

Conclusion

Our results show that 3D glioblastoma organoid models secrete extracellular vesicles with an altered cargo compared to corresponding conventional 2D cultures. Extracellular vesicles from 3D cultures were found to contain signaling molecules associated with the immune regulatory signaling pathways and as such could potentially change the surrounding microenvironment towards tumor progression and immunosuppressive conditions. These findings suggest the use of 3D glioblastoma models for further clinical biomarker studies as well as investigation of new therapeutic options.

Extracellular RNA in oncogenesis, metastasis and drug resistance

Extracellular vesicles and nanoparticles (EVPs) are now recognized as a novel form of cell-cell communication. All cells release a wide array of heterogeneous EVPs with distinct protein, lipid, and RNA content, dependent on the pathophysiological state of the donor cell. The overall cargo content in EVPs is not equivalent to cellular levels, implying a regulated pathway for selection and export. In cancer, release and uptake of EVPs within the tumour microenvironment can influence growth, proliferation, invasiveness, and immune evasion. Secreted EVPs can also have distant, systemic effects that can promote metastasis. Here, we review current knowledge of EVP biogenesis and cargo selection with a focus on the role that extracellular RNA plays in oncogenesis and metastasis. Almost all subtypes of RNA have been identified in EVPs, with miRNAs being the best characterized. We review the roles of specific miRNAs that have been detected in EVPs and that play a role in oncogenesis and metastasis.

FOXO1-miR-506 axis promotes chemosensitivity to temozolomide and suppresses invasiveness in glioblastoma through a feedback loop of FOXO1/miR-506/ETS1/FOXO1

To explore the role of forkhead box protein O1 (FOXO1) in the progression of glioblastoma multiforme (GBM) and related drug resistance, we deciphered the roles of FOXO1 and miR-506 in proliferation, apoptosis, migration, invasion, autophagy, and temozolomide (TMZ) sensitivity in the U251 cell line using in vitro and in vivo experiments. Cell viability was tested by a cell counting kit-8 (CCK8) kit; migration and invasion were checked by the scratching assay; apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining and flow cytometry. The construction of plasmids and dual-luciferase reporter experiment were carried out to find the interaction site between FOXO1 and miR-506. Immunohistochemistry was done to check the protein level in tumors after the in vivo experiment. We found that the FOXO1-miR-506 axis suppresses GBM cell invasion and migration and promotes GBM chemosensitivity to TMZ, which was mediated by autophagy. FOXO1 upregulates miR-506 by binding to its promoter to enhance transcriptional activation. MiR-506 could downregulate E26 transformation-specific 1 (ETS1) expression by targeting its 3'-untranslated region (UTR). Interestingly, ETS1 promoted FOXO1 translocation from the nucleus to the cytosol and further suppressed the FOXO1-miR-506 axis in GBM cells. Consistently, both miR-506 inhibition and ETS1 overexpression could rescue FOXO1 overactivation-mediated TMZ chemosensitivity in mouse models. Our study demonstrated a negative feedback loop of FOXO1/miR-506/ETS1/FOXO1 in GBM in regulating invasiveness and chemosensitivity. Thus, the above axis might be a promising therapeutic target for GBM.

The Role of MicroRNAs in Development of Endometrial Cancer: A Literature Review

Endometrial cancer (EC) ranks as the second most common gynaecological cancer worldwide. EC patients are diagnosed at an early clinical stage and generally have a good prognosis. Therefore, there is a dire need for development of a specific marker for early detection of endometrial adenocarcinoma. The development of EC is conditioned by a multistep process of oncogenic upregulation and tumor suppressor downregulation as shown by molecular genetic evidence. In this setting, microRNAs appear as significant regulators of gene expression and several variations in the expression of microRNAs have been implicated in normal endometrium, endometrial tissue, metrorrhagia, and endometrial cancer. Furthermore, microRNAs act as highly precise, sensitive, and robust molecules, making them potential markers for diagnosing specific cancers and their progression. With the rising incidence of EC, its management remains a vexing challenge and diagnostic methods for the disease are limited to invasive, expensive, and inaccurate tools. Therefore, the prospect of exploiting the utility of microRNAs as potential candidates for diagnosis and therapeutic use in EC seems promising.

Comparison of Oncogenes, Tumor Suppressors, and MicroRNAs Between Schizophrenia and Glioma: The Balance of Power

The risk of cancer in schizophrenia has been controversial. Confounders of the issue are cigarette smoking in schizophrenia, and antiproliferative effects of antipsychotic medications. The author has previously suggested comparison of a specific cancer like glioma to schizophrenia might help determine a more accurate relationship between cancer and schizophrenia. To accomplish this goal, the author performed three comparisons of data; the first a comparison of conventional tumor suppressors and oncogenes between schizophrenia and cancer including glioma. This comparison determined schizophrenia has both tumor-suppressive and tumor-promoting characteristics. A second, larger comparison between brain-expressed microRNAs in schizophrenia with their expression in glioma was then performed. This identified a core carcinogenic group of miRNAs in schizophrenia offset by a larger group of tumor-suppressive miRNAs. This proposed "balance of power" between oncogenes and tumor suppressors could cause neuroinflammation. This was assessed by a third comparison between schizophrenia, glioma and inflammation in asbestos-related lung cancer and mesothelioma (ALRCM). This revealed that schizophrenia shares more oncogenic similarity to ALRCM than glioma.

A novel necroptosis-associated miRNA signature predicting prognosis of endometrial cancer and correlated with immune infiltration

OBJECTIVE

Necroptosis is a form of programmed cell death identified irrelevant to caspases, which plays an important role in the tumorigenesis and development of cancer. MicroRNAs (miRNAs) are important regulators of both necroptosis and cancer.

MATERIALS AND METHODS

Expression of sixteen necroptosis-associated miRNAs were analyzed in 546 endometrial cancer (EC) tissues and 33 paracancerous samples from the Cancer Genome Atlas (TCGA). Cox regression analysis was used to evaluate the correlations between miRNAs and overall survival. MiRNAs risk score (Mrs) and nomogram were established to assess the potential value of necroptosis-related miRNAs on prognosis. Expression of miRNA-148a-3p in endometrial cancer cells and endometrial epithelial cells was detected by quantitative real-time PCR (qRT-PCR). The targets genes of miR-148a-3p were predicted using miRDB, miRTarBase and TargetScan and the prognostic-related genes were screened. Immune infiltration analysis was conducted to explore the potential mechanism of these target genes.

RESULTS

We identified fourteen differentially expressed miRNAs and selected seven miRNAs (miR-15a-5p, miR148a-3p, miR-7-5p, miR-141-3p, miR-200a-5p, miR-223-3p, miR-16-5p) for prognostic-model construction. The area under the curve (AUC) of receiver operating characteristic (ROC) curve for 1-, 2- and 5-year survival were 0.678, 0.652 and 0.656 respectively. Multivariate analysis revealed that the Mrs was an independent prognostic factor considering other risk factors (HR = 1.928, 95% CI = 1.072-3.467, P = 0.028). Among these miRNAs, miRNA-148a-3p was up-regulated in cancer tissues and cells, and Kaplan-Meier analysis showed its significance in overall survival (OS). The target genes, DNAJB4 and PRNP, were associated with poor prognosis and correlated with tumor immune infiltration.

CONCLUSIONS

Our study constructed a novel necroptosis-associated miRNAs model for prognosis prediction, and DNAJB4 and PRNP may be therapeutic targets for EC.

The "Superoncogene" Myc at the Crossroad between Metabolism and Gene Expression in Glioblastoma Multiforme

The concept of the Myc (c-myc, n-myc, l-myc) oncogene as a canonical, DNA-bound transcription factor has consistently changed over the past few years. Indeed, Myc controls gene expression programs at multiple levels: directly binding chromatin and recruiting transcriptional coregulators; modulating the activity of RNA polymerases (RNAPs); and drawing chromatin topology. Therefore, it is evident that Myc deregulation in cancer is a dramatic event. Glioblastoma multiforme (GBM) is the most lethal, still incurable, brain cancer in adults, and it is characterized in most cases by Myc deregulation. Metabolic rewiring typically occurs in cancer cells, and GBM undergoes profound metabolic changes to supply increased energy demand. In nontransformed cells, Myc tightly controls metabolic pathways to maintain cellular homeostasis. Consistently, in Myc-overexpressing cancer cells, including GBM cells, these highly controlled metabolic routes are affected by enhanced Myc activity and show substantial alterations. On the other hand, deregulated cancer metabolism impacts Myc expression and function, placing Myc at the intersection between metabolic pathway activation and gene expression. In this review paper, we summarize the available information on GBM metabolism with a specific focus on the control of the Myc oncogene that, in turn, rules the activation of metabolic signals, ensuring GBM growth.

MEIS1 Is a Common Transcription Repressor of the miR-23a and NORHA Axis in Granulosa Cells

MicroRNA-23a (miR-23a) is an endogenous small activating RNA (saRNA) involved in ovarian granulosa cell (GC) apoptosis and sow fertility by activating lncRNA NORHA transcription. Here, we reported that both miR-23a and NORHA were repressed by a common transcription factor MEIS1, which forms a small network regulating sow GC apoptosis. We characterized the pig miR-23a core promoter, and the putative binding sites of 26 common transcription factors were detected in the core promoters of both miR-23a and NORHA. Of them, transcription factor MEIS1 expression was the highest in the ovary, and widely distributed in various ovarian cells, including GCs. Functionally, MEIS1 is involved in follicular atresia by inhibiting GC apoptosis. Luciferase reporter and ChIP assays showed that transcription factor MEIS1 represses the transcription activity of miR-23a and NORHA through direct binding to their core promoters. Furthermore, MEIS1 represses miR-23a and NORHA expression in GCs. Additionally, MEIS1 inhibits the expression of FoxO1, a downstream of the miR-23a/NORHA axis, and GC apoptosis by repressing the miR-23a/NORHA axis. Overall, our findings point to MEIS1 as a common transcription repressor of miR-23a and NORHA, and develop the miR-23a/NORHA axis into a small regulatory network regulating GC apoptosis and female fertility.

MicroRNA-based therapy for glioblastoma: Opportunities and challenges

Glioblastoma (GBM) is the most common and aggressive primary malignant brain tumor and is characterized by high mortality and morbidity rates and unpredictable clinical behavior. The disappointing prognosis for patients with GBM even after surgery and postoperative radiation and chemotherapy has fueled the search for specific targets to provide new insights into the development of modern therapies. MicroRNAs (miRNAs/miRs) act as oncomirs and tumor suppressors to posttranscriptionally regulate the expression of various genes and silence many target genes involved in cell proliferation, the cell cycle, apoptosis, invasion, stem cell behavior, angiogenesis, the microenvironment and chemo- and radiotherapy resistance, which makes them attractive candidates as prognostic biomarkers and therapeutic targets or agents to advance GBM therapeutics. However, one of the major challenges of successful miRNA-based therapy is the need for an effective and safe system to deliver therapeutic compounds to specific tumor cells or tissues in vivo, particularly systems that can cross the blood-brain barrier (BBB). This challenge has shifted gradually as progress has been achieved in identifying novel tumor-related miRNAs and their targets, as well as the development of nanoparticles (NPs) as new carriers to deliver therapeutic compounds. Here, we provide an up-to-date summary (in recent 5 years) of the current knowledge of GBM-related oncomirs, tumor suppressors and microenvironmental miRNAs, with a focus on their potential applications as prognostic biomarkers and therapeutic targets, as well as recent advances in the development of carriers for nontoxic miRNA-based therapy delivery systems and how they can be adapted for therapy.

TRAF3IP3 promotes glioma progression through the ERK signaling pathway

TRAF3IP3 was reportedly associated with poor prognosis in patients with melanoma; however, its role in glioma is unknown. We aimed to demonstrate the relationship between TRAF3IP3 and glioma and to investigate the potential role of TRAF3IP3 in glioma. Datasets were collected from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. We used the Wilcoxon rank-sum test to compared TRAF3IP3 expression in normal and glioma tissues. Kaplan–Meier analysis was performed to evaluate the correlation between TRAF3IP3 and patient survival rate. Gene set enrichment analysis (GSEA) was used to annotate the biological function of TRAF3IP3 in glioma. We also examined the effects of TRAF3IP3 on glioma progression, including characteristics such as cell proliferation, migration, and invasion, using cell proliferation, wound healing, and Transwell assays, respectively, paired with in vitro glioma cell lines and in vivo mouse xenograft models to determine the molecular mechanisms underlying these effects. High TRAF3IP3 expression in glioma tissues was associated with patients with neoplasm cancer tissue source site, and poorer overall survival (OS) (p = 0.03), which was validated using TCGA. GSEA revealed the enrichment of neuroactive ligand–receptor interactions, the olfactory pathway, proteasome pathway, cytokine–cytokine receptor interactions, and calcium signaling pathway in the TRAF3IP3 high-expression phenotype. TRAF3IP3 knockdown markedly suppressed the proliferation, migration, and invasion abilities of U251 glioma cells, whereas TRAF3IP3 overexpression notably promoted the progression of U118 cell tumors. Mechanistic studies revealed that TRAF3IP3 upregulated p-ERK expression in glioma cells. Notably, the ERK signaling pathway inhibitor U0126 drastically attenuated the effects of TRAF3IP3 on p-ERK and markedly blocked its tumor-promoting activity. TRAF3IP3 overexpression also promoted in vivo tumor growth in a nude mouse xenograft model. Collectively, TRAF3IP3 stimulates glioma cell proliferation, migration, and invasion, at least partly by activating the ERK signaling pathway. We hypothesize that TRAF3IP3 may participate in glioma development via the ERK signaling pathway and that elevated TRAF3IP3 expression may serve as a potential biomarker for glioma prognosis.

Significance of HOXD transcription factors family in progression, migration and angiogenesis of cancer

The transcription factors (TFs) of the HOX family play significant roles during early embryonic development and cellular processes. They also play a key role in tumorigenesis as tumor oncogenes or suppressors. Furthermore, TFs of the HOXD geFIne cluster affect proliferation, migration, and invasion of tumors. Consequently, dysregulated activity of HOXD TFs has been linked to clinicopathological characteristics of cancer. HOXD TFs are regulated by non-coding RNAs and methylation of DNA on promoter and enhancer regions. In addition, HOXD genes modulate the biological function of cancer cells via the MEK and AKT signaling pathways, thus, making HOXD TFs, a suitable molecular marker for cancer prognosis and therapy. In this review, we summarized the roles of HOXD TFs in different cancers and highlighted its potential as a diagnostic and therapeutic target.

Construction of a Novel MYC-Associated ceRNA Regulatory Network to Identify Prognostic Biomarkers in Colon Adenocarcinoma

Colorectal cancer (CRC) includes colon adenocarcinoma (COAD) and rectal adenocarcinoma (READ). Competitive endogenous RNA (ceRNA) is crucial for cancer pathogenesis. Abnormal expression of MYC is generally associated with a poor colon adenocarcinoma prognosis. The present study aimed to identify a novel MYC-associated ceRNA regulatory network and identify potential prognostic markers associated with COAD. We obtained the transcriptome sequencing profiles of 462 COAD cases from the TCGA database and analyzed differentially expressed genes (DEGs) in MYC high expression (MYChigh) and MYC low expression (Myclow) tumors. We identified an important lncRNA, LINC00114, which effectively predicts overall survival and plays a protective role in COAD. Moreover, the LINC00114/miR-216a-5p axis was identified as a clinical prognostic model. The predicted target genes of the LINC00114/miR-216a-5p axis include uromodulin Like 1 (UMODL1) and oncoprotein induced transcript 3 (OIT3), which are closely related to the survival and prognosis of COAD patients. In summary, we constructed a novel ceRNA regulatory network and identified potential biomarkers for the targeted therapy and prognosis of COAD.

Patient-individual phenotypes of glioblastoma stem cells are conserved in culture and associate with radioresistance, brain infiltration and patient prognosis

Identification of prognostic or predictive molecular markers in glioblastoma resection specimens may lead to strategies for therapy stratification and personalized treatment planning. Here, we analyzed in primary glioblastoma stem cell (pGSC) cultures the mRNA abundances of 7 stem cell (MSI1, Notch1, nestin, Sox2, Oct4, FABP7, ALDH1A3), and 3 radioresistance or invasion markers (CXCR4, IK_Ca , BK_Ca ). From these abundances, an mRNA signature was deduced which describes the mesenchymal-to-proneural expression profile of an individual GSC culture. To assess its functional significance, we associated the GSC mRNA signature with the clonogenic survival after irradiation with 4 Gy and the fibrin matrix invasion of the GSC cells. In addition, we compared the molecular pGSC mRNA signature with the tumor recurrence pattern and the overall survival of the glioblastoma patients from whom the pGSC cultures were derived. As a result, the molecular pGSC mRNA signature correlated positively with the pGSC radioresistance and matrix invasion capability in vitro. Moreover, patients with a mesenchymal (> median) mRNA signature in their pGSC cultures exhibited predominantly a multifocal tumor recurrence and a significantly (univariate log rank test) shorter overall survival than patients with proneural (≤ median mRNA signature) pGSCs. The tumors of the latter recurred predominately unifocally. We conclude that our pGSC cultures induce/select those cell subpopulations of the heterogeneous brain tumor that determine disease progression and therapy outcome. In addition, we further postulate a clinically relevant prognostic/predictive value for the 10 mRNAs-based mesenchymal-to-proneural signature of the GSC subpopulations in glioblastoma.

Downstream of the HOX genes: explaining conflicting tumour suppressor and oncogenic functions in cancer

The HOX genes are a highly conserved group of transcription factors that have key roles in early development, but which are also highly expressed in most cancers. Many studies have found strong associative relationships between the expression of individual HOX genes in tumours and clinical parameters including survival. For the majority of HOX genes, high tumour expression levels seem to be associated with a worse outcome for patients, and in some cases this has been shown to result from the activation of pro-oncogenic genes and pathways. However, there are also many studies that indicate a tumour suppressor role for some HOX genes, sometimes with conclusions that contradict earlier work. In this review, we have attempted to clarify the role of HOX genes in cancer by focusing on their downstream targets as identified in studies that provide experimental evidence for their activation or repression. On this basis, the majority of HOX genes would appear to have a pro-oncogenic function, with the notable exception of HOXD10, which acts exclusively as a tumour suppressor. HOX proteins regulate a wide range of target genes involved in metastasis, cell death, proliferation, and angiogenesis, and activate key cell signalling pathways. Furthermore, for some functionally related targets, this regulation is achieved by a relatively small subgroup of HOX genes.

The Role of MiRNA in Cancer: Pathogenesis, Diagnosis, and Treatment

Cancer is also determined by the alterations of oncogenes and tumor suppressor genes. These gene expressions can be regulated by microRNAs (miRNA). At this point, researchers focus on addressing two main questions: "How are oncogenes and/or tumor suppressor genes regulated by miRNAs?" and "Which other mechanisms in cancer cells are regulated by miRNAs?" In this work we focus on gathering the publications answering these questions. The expression of miRNAs is affected by amplification, deletion or mutation. These processes are controlled by oncogenes and tumor suppressor genes, which regulate different mechanisms of cancer initiation and progression including cell proliferation, cell growth, apoptosis, DNA repair, invasion, angiogenesis, metastasis, drug resistance, metabolic regulation, and immune response regulation in cancer cells. In addition, profiling of miRNA is an important step in developing a new therapeutic approach for cancer.

Restoring HOXD10 Exhibits Therapeutic Potential for Ameliorating Malignant Progression and 5-Fluorouracil Resistance in Colorectal Cancer

Emerging evidence suggests that hypermethylation of HOXD10 plays an important role in human cancers. However, the biological and clinical impacts of HOXD10 overmethylation and its downstream targets in colorectal cancer remain unknown. We evaluated the methylation level of HOXD10 in paired cancer and normal tissues (n = 42) by using pyrosequencing, followed by validation of the methylation status of HOXD10 from The Cancer Genome Atlas (TCGA) datasets with 302 cancer tissues and 38 normal tissues. The biological function of HOXD10 was characterized in cell lines. We further evaluated the effects of HOXD10 and its targets on chemoresistance in our established resistant cell lines and clinical cohort (n = 66). HOXD10 was found frequently methylated in colorectal cancer, and its hypermethylation correlates with its low expression level, advanced disease, and lymph node metastasis. Functionally, HOXD10 acts as a tumor suppressor gene, in which HOXD10-expressing cells showed suppressed cell proliferation, colony formation ability, and migration and invasion capacity. Mechanistically, DNMT1, DNMT3B, and MeCP2 were recruited in the HOXD10 promoter, and demethylation by 5-Aza-2′-deoxycytidine (5-Aza-CdR) treatment or MeCP2 knockdown can sufficiently induce HOXD10 expression. HOXD10 regulates the expressions of miR-7 and IGFBP3 in a promoter-dependent manner. Restoration of the expression of HOXD10 in 5-fluorouracil (5-FU)-resistant cells significantly upregulates the expressions of miR-7 and IGFBP3 and enhances chemosensitivity to 5-FU. In conclusion, we provide novel evidence that HOXD10 is frequently methylated, silenced, and contributes to the development of colorectal cancers. Restoration of HOXD10 activates the expressions of miR-7 and IGFBP3 and results in an inhibited phenotype biologically, suggesting its potential therapeutic relevance in colorectal cancer (CRC).

uPAR: An Essential Factor for Tumor Development

Tumorigenesis is closely related to the loss of control of many genes. Urokinase-type plasminogen activator receptor (uPAR), a glycolipid-anchored protein on the cell surface, is controlled by many factors in tumorigenesis and is expressed in many tumor tissues. In this review, we summarize the regulatory effects of the uPAR signaling pathway on processes and factors related to tumor progression, such as tumor cell proliferation, adhesion, metastasis, glycolysis, tumor microenvironment and angiogenesis. Overall, the evidence accumulated to date suggests that uPAR induction by tumor progression may be one of the most important factors affecting therapeutic efficacy. An improved understanding of the interactions between uPAR and its coreceptors in cancer will provide critical biomolecular information that may help to better predict the disease course and response to therapy.

Homeobox Genes in Cancers: From Carcinogenesis to Recent Therapeutic Intervention

The homeobox (HOX) genes encoding an evolutionarily highly conserved family of homeodomain-containing transcriptional factors are essential for embryogenesis and tumorigenesis. HOX genes are involved in cell identity determination during early embryonic development and postnatal processes. The deregulation of HOX genes is closely associated with numerous human malignancies, highlighting the indispensable involvement in mortal cancer development. Since most HOX genes behave as oncogenes or tumor suppressors in human cancer, a better comprehension of their upstream regulators and downstream targets contributes to elucidating the function of HOX genes in cancer development. In addition, targeting HOX genes may imply therapeutic potential. Recently, novel therapies such as monoclonal antibodies targeting tyrosine receptor kinases, small molecular chemical inhibitors, and small interfering RNA strategies, are difficult to implement for targeting transcriptional factors on account of the dual function and pleiotropic nature of HOX genes-related molecular networks. This paper summarizes the current state of knowledge on the roles of HOX genes in human cancer and emphasizes the emerging importance of HOX genes as potential therapeutic targets to overcome the limitations of present cancer therapy.

Platinum nanoparticles Protect Against Lipopolysaccharide-Induced Inflammation in Microglial BV-2 Cells via Decreased Oxidative Damage and Increased Phagocytosis

Neuroinflammation and oxidative stress cooperate to compromise the function of the central nervous system (CNS). Colloidal platinum nanoparticles (Pt NPs) are ideal candidates for reducing the deleterious effects of neuroinflammation since they act as free radical scavengers. Here we evaluated the effects of Pt NPs on several markers of lipopolysaccharide (LPS)-induced inflammation in cultured BV-2 microglial cells. BV-2 cells were treated with increased dilutions (1-100 ppm) of Colloidal Pt and/or LPS (1-10 µg/mL) at different exposure times. Three different protocols of exposure were used combining Pt NPs and LPS: (a) conditioning-protective effect (pre-post-treat), (b) therapeutic effect (co-treat) and (c) conditioning-therapeutic effect (pre-co-treat). After exposure to LPS for 24 h, cells were used for assessment of cell viability, reactive oxygen species (ROS) generation, lactate dehydrogenase (LDH) activity, apoptosis and caspase-3 levels, cell proliferation, mitochondrial membrane potential, inducible nitric oxide (iNOS) activity, pro-inflammatory cytokine (IL-1β, TNF-α and IL-6) levels, and phagocytic activity. Low concentrations (below or equal to 10 ppm) of Colloidal Pt prevented or ameliorated the LPS-induced increase in ROS formation, loss of mitochondrial membrane potential, induction of apoptosis, increase in LDH release, increase in pro-inflammatory cytokines and iNOS, inhibition of phagocytosis linked to microglial persistence in the M1 phase phenotype, loss of cell adhesion, differentiation and/or proliferation, as well as loss of cell viability. These protective effects were evident when cells were preconditioned with Pt NPs prior to LPS treatment. Collectively, the findings demonstrate that at low concentrations, Pt NPs can regulate the function and phenotype of BV-2 cells, activating protective mechanisms to maintain the microglial homeostasis and reduce inflammatory events triggered by the inflammatory insults induced by LPS. These preventive/protective effects on the LPS pro-inflammatory model are linked to the antioxidant properties and phagocytic activity of these NPs.

Circ_0000317/microRNA-520g/HOXD10 axis affects the biological characteristics of colorectal cancer

Circular RNAs (circRNAs) are a class of noncoding RNAs that are widely expressed in cancer tissues and play a pro- or anticancer role in modulating cancer progression. This work is aimed to probe the biological role of circ_0000317 in colorectal cancer (CRC) and its underlying mechanism. Circ_0000317 was selected from the circRNA microarray datasets (GSE121895). Quantitative real-time polymerase chain reaction was utilized to examine circ_0000317, microRNA (miR)-520g, and homeobox D10 (HOXD10) mRNA expression in CRC. Cell Counting Kit-8 and Transwell experiments were conducted to examine the effects of circ_0000317 on proliferation, migration, and invasion of CRC cells. Bioinformatic analysis and dual-luciferase reporter gene experiments were implemented to predict and validate the targeting relationship between circ_0000317 and miR-520g, miR-520g, and HOXD10. Western blot was employed to examine HOXD10 expression at protein level in CRC cells. Circ_0000317 and HOXD10 mRNA expression were unveiled to be down-modulated and miR-520g expression was up-modulated in CRC. Functionally, circ_0000317 overexpression repressed CRC cell proliferation, migration, and invasion. Mechanistically, miR-520g was a direct target of circ_0000317 and miR-520g specifically modulated HOXD10 expression. Furthermore, miR-520g mimics partially counteracted the suppressing effect of circ_0000317 on malignant phenotype of CRC cells. Circ_0000317 represses CRC progression by targeting miR-520g and modulating HOXD10 expression. Hence, circ_0000317 may be a promising diagnostic biomarker and a therapeutic target for CRC.

MiR-501 promotes tumor proliferation and metastasis by targeting HOXD10 in endometrial cancer

Background

Several studies have shown the crucial role of miR-501 in regulating cellular pathology in various cancers. However, the function and expression of miR-501 in endometrial cancer (EC) remain obscure.

Methods

The expression of miR-501 was determined using quantitative real-time PCR. MTT assay, colony formation assay and cell cycle analysis were used to evaluate the proliferation ability. Migration and invasion were assessed using transwell assay. Tumor formation in nude mice was used to observe the effects of miR-501 on cell proliferation and migration in vivo. Luciferase assay, quantitative real-time PCR and western blot were applied to determine that HOXD10 was the target gene of miR-501.

Results

In this study, we observed significantly up-regulated expression of miR-501 in endometrial cancer, which correlated with higher pelvic lymph node metastasis and shorter overall survival in high-grade endometrial cancer. High expression of miR-501 was also found in the copy-number-high group than other groups. Moreover, in vitro and in vivo assay showed that overexpression of miR-501 can promote proliferation and metastasis. Mechanistically, we found that miR-501 promotes tumor progression by directly targeting HOXD10. Further study also indicated that miR-501 overexpression can activate the AKT/mTOR pathway.

Conclusions

MiR-501, which functions as an oncomir in endometrial cancer, might be a potential therapeutic target in high grade endometrial cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11658-021-00268-7.

Perspective of mesenchymal transformation in glioblastoma

Despite aggressive multimodal treatment, glioblastoma (GBM), a grade IV primary brain tumor, still portends a poor prognosis with a median overall survival of 12–16 months. The complexity of GBM treatment mainly lies in the inter- and intra-tumoral heterogeneity, which largely contributes to the treatment-refractory and recurrent nature of GBM. By paving the road towards the development of personalized medicine for GBM patients, the cancer genome atlas classification scheme of GBM into distinct transcriptional subtypes has been considered an invaluable approach to overcoming this heterogeneity. Among the identified transcriptional subtypes, the mesenchymal subtype has been found associated with more aggressive, invasive, angiogenic, hypoxic, necrotic, inflammatory, and multitherapy-resistant features than other transcriptional subtypes. Accordingly, mesenchymal GBM patients were found to exhibit worse prognosis than other subtypes when patients with high transcriptional heterogeneity were excluded. Furthermore, identification of the master mesenchymal regulators and their downstream signaling pathways has not only increased our understanding of the complex regulatory transcriptional networks of mesenchymal GBM, but also has generated a list of potent inhibitors for clinical trials. Importantly, the mesenchymal transition of GBM has been found to be tightly associated with treatment-induced phenotypic changes in recurrence. Together, these findings indicate that elucidating the governing and plastic transcriptomic natures of mesenchymal GBM is critical in order to develop novel and selective therapeutic strategies that can improve both patient care and clinical outcomes. Thus, the focus of our review will be on the recent advances in the understanding of the transcriptome of mesenchymal GBM and discuss microenvironmental, metabolic, and treatment-related factors as critical components through which the mesenchymal signature may be acquired. We also take into consideration the transcriptomic plasticity of GBM to discuss the future perspectives in employing selective therapeutic strategies against mesenchymal GBM.

The adaptive transition of glioblastoma stem cells and its implications on treatments

Glioblastoma is the most malignant tumor occurring in the human central nervous system with overall median survival time <14.6 months. Current treatments such as chemotherapy and radiotherapy cannot reach an optimal remission since tumor resistance to therapy remains a challenge. Glioblastoma stem cells are considered to be responsible for tumor resistance in treating glioblastoma. Previous studies reported two subtypes, proneural and mesenchymal, of glioblastoma stem cells manifesting different sensitivity to radiotherapy or chemotherapy. Mesenchymal glioblastoma stem cells, as well as tumor cells generate from which, showed resistance to radiochemotherapies. Besides, two metabolic patterns, glutamine or glucose dependent, of mesenchymal glioblastoma stem cells also manifested different sensitivity to radiochemotherapies. Glutamine dependent mesenchymal glioblastoma stem cells are more sensitive to radiotherapy than glucose-dependent ones. Therefore, the transition between proneural and mesenchymal subtypes, or between glutamine-dependent and glucose-dependent, might lead to tumor resistance to radiochemotherapies. Moreover, neural stem cells were also hypothesized to participate in glioblastoma stem cells mediated tumor resistance to radiochemotherapies. In this review, we summarized the basic characteristics, adaptive transition and implications of glioblastoma stem cells in glioblastoma therapy.

Identification of a Novel Metastasis-Related miRNAs-Based Signature for Predicting the Prognosis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common internal malignancies worldwide and is associated with a poor prognosis. Abnormal expression of miRNAs is believed to play a role in the recurrent metastasis of HCC. However, limited studies on the role of miRNAs in HCC metastasis have been carried out. Therefore, this study is aimed at exploring the potential value of metastasis-related miRNAs (MRMs) in HCC. We retrieved MRMs were from the Human Cancer Metastasis Database. Differential miRNAs were identified for tumor samples of HCC patients and normal samples based on the TCGA database. Further, univariate and multivariate Cox regression analyses were used to screen MRMs known to be independent prognostic factors in HCC. These MRMs were then used to build a prognostic signature. All patients were classified into high-risk and low-risk groups based on the median of the signature scores. Moreover, GO and KEGG pathway enrichment analyses were performed to predict the function of these MRMs. Finally, a nomogram was constructed to predict the OS of patients at 1, 2, and 3 years. In our study, a total of seven prognostic MRMs (miR-140-3p, miR-9-5p, miR-942-5p, miR-324-3p, miR-29c-5p, miR-551a, and miR-149-5p) were identified and used for constructing the prognostic signature based on the training cohort. Patients in the low-risk HCC group showed better overall survival (OS) than those in the high-risk group. The results were validated using the validation cohort. In summary, the findings of this study provide evidence that MRMs-based prognostic signature is an independent biomarker in the prognosis of HCC patients.

Low concentration of Bupivacaine ameliorates painful diabetic neuropathy by mediating miR-23a/PDE4B axis in microglia

Bupivacaine (Bup) has a certain research basis in pain-related diseases, but it has not been studied in painful diabetic neuropathy. In this study, we investigated the role of Bupivacaine in painful diabetic neuropathy. Mouse model with painful diabetic neuropathy was established, and then treated with different concentrations of Bupivacaine. The blood glucose level in the tail vein and the changes in body weight was measured. The mechanical allodynia, thermal hyperalgesia and thermal allodynia was assessed by pain behavioral tests. Microglia were treated with high glucose (HG) and different concentrations of Bupivacaine. The levels of inflammatory cytokines were detected by using Enzyme-linked immunosorbent assays. Dual luciferase reporter assay explored the relationship between miR-23a and phosphodiesterase 4 B (PDE4B). The results displayed that Bupivacaine ameliorated the mechanical allodynia, thermal hyperalgesia, and thermal allodynia in mice with painful diabetic neuropathy, and is more effective at low concentration. Moreover, low concentration of Bupivacaine inhibited inflammation and promoted miR-23a expression in mice with painful diabetic neuropathy and in microglia induced by HIGH GLUCOSE. Overexpression of miR-23a reduced the levels of inflammatory cytokines by down-regulating PDE4B expression. Knockdown of miR-23a reversed the inhibition effect of Bupivacaine on microglial inflammation. These results revealed that low concentration of Bupivacaine inhibited microglial inflammation through down-regulating PDE4B via miR-23a, thereby attenuated painful diabetic neuropathy.

Inhibition of microRNA-10b-5p up-regulates HOXD10 to attenuate Alzheimer's disease in rats via the Rho/ROCK signalling pathway

OBJECTIVE

It is believed that microRNAs (miRNAs) participate in the pathogenesis of Alzheimer's disease (AD), but the specified function of miR-10b-5p in the disease has not been thoroughly understood. Thereafter, this research aimed to assess the function of miR-10b-5p in AD.

METHODS

Rat AD models were established by injected with amyloid-β_1-42 (Aβ_1-42), which were mainly treated with lentivirus-miR-10b-5p inhibitor, or lentivirus-overexpressed homeobox D10 (HOXD10). MiR-10b-5p, HOXD10, RhoA, ROCK1 and ROCK2 expression in rat hippocampal tissues were determined. Afterwards, the behaviour of rats was tested, and neuronal apoptosis, pathological injury, and inflammatory factors and oxidative stress-related factors were all assessed. Finally, the target relation between miR-10b-5p and HOXD10 was detected.

RESULTS

MiR-10b-5p was upregulated while HOXD10 was downregulated, and the Rho/ROCK signalling pathway was activated in hippocampal tissues of rats with AD. Inhibition of miR-10b-5p could attenuate the neuronal apoptosis, pathological injury, inflammation reaction, and oxidative stress by elevating HOXD10 and inhibiting the Rho/ROCK signalling pathway in AD rats. Moreover, HOXD10 was targeted by miR-10b-5p.

CONCLUSION

Inhibited miR-10b-5p decelerated the development of AD by promoting HOXD10 and inactivating the Rho/ROCK signalling pathway, and our findings may contribute to the exploration of AD treatment.

CircRNA circPTK2 Might Suppress Cancer Cell Invasion and Migration of Glioblastoma by Inhibiting miR-23a Maturation

BACKGROUND

CircRNA circPTK2 plays opposite roles in different cancers, while its role in glioblastoma is unknown. The aim of this study was to explore the involvement of circPTK2 in glioblastoma.

METHODS

Expression of circPTK2, mature miR-23a, and premature miR-23a in paired cancer and non-cancer tissues from glioblastoma patients (n = 60) was analyzed by RT-qPCR. Pearson's correlation coefficient was used to analyze the correlations between gene expressions. The effects of circPTK2 overexpression on miR-23a maturation were analyzed by transfecting circPTK2 expression vector into glioblastoma cells, followed by determining the expression of mature miR-23a and premature miR-23a by RT-qPCR. Transwell assays were carried out to explore the role of circPTK2 and miR-23a in regulating glioblastoma cell invasion and migration.

RESULTS

We found that circPTK2 was downregulated in GBM and was inversely correlated with mature miR-23a, but not premature miR-23a. GBM cells transfected with circPTK2 expression vector showed significantly downregulated mature miR-23a, but not premature miR-23a. Transwell assay analysis showed that circPTK2 overexpression decreased cell invasion and migration, while miR-23a increased cell invasion and migration. Moreover, miR-23a overexpression reversed the inhibitory effects of circPTK2 overexpression on cell behaviors.

CONCLUSION

CircPTK2 might suppress cancer cell invasion and migration by inhibiting the maturation of miR-23a.

Regulatory mechanism of miR-525-5p in over-invasion of trophoblast

AIM

To investigate the mechanism of miRNA-525-5p (miR-525-5p) in regulating the invasion of trophoblast cells.

METHODS

The expressions of miR-525-5p and Homeobox D10 (HOXD10) in pre-eclampsia (PE) and normal placentas were detected. Besides the expressions of miR-525-5p and HOXD10, the levels of Vimentin, N-cadherin and E-cadherin in human trophoblast (HTR)-8 cells were also measured after cell transfection. 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT) and Transwell assays assessed the proliferative and invasive capabilities of HTR-8 cells, respectively. Dual-luciferase reporter assay verified the targeting relationship between miR-525-5p and HOXD10.

RESULTS

MiR-525-5p was lowly expressed and HOXD10 was highly expressed in PE placentas. MiR-525-5p inhibition or HOXD10 overexpression suppressed proliferation, invasion and epithelial-mesenchymal transition (EMT) of HTR-8 cells. MiR-525-5p overexpression or HOXD10 knockdown promoted proliferation, invasion and EMT of HTR-8 cells. HOXD10 was a downstream target of miR-525-5p. Inhibiting HOXD10 reversed the suppressive effects of miR-525-5p inhibition on proliferation, invasion and EMT of HTR-8 cells.

CONCLUSION

MiR-525-5p mediates the invasion of trophoblast cells by regulating HOXD10, which provides new therapeutic targets for PE treatment.

Identification of miR-515-3p and its targets, vimentin and MMP3, as a key regulatory mechanism in esophageal cancer metastasis: functional and clinical significance

Metastasis is the main factor of treatment failure in cancer patients, but the underlying mechanism remains to be elucidated and effective new treatment strategies are urgently needed. This study aims to explore novel key metastasis-related microRNAs (miRNAs) in esophageal squamous cell carcinoma (ESCC). By comparing miRNA profiles of the highly metastatic ESCC cell sublines, we established through serial in vivo selection with the parental cells, we found that the expression level of miR-515-3p was lower in ESCC tumor tissues than adjacent normal tissues, further decreased in metastatic tumors, and moreover, markedly associated with advanced stage, metastasis and patient survival. The in vitro and in vivo assays suggested that miR-515-3p could increase the expression of the epithelial markers as well as decrease the expression of the mesenchymal markers, and more importantly, suppress invasion and metastasis of ESCC cells. Mechanistically, we revealed that miR-515-3p directly regulated vimentin and matrix metalloproteinase-3 (MMP3) expression by binding to the coding sequence and 3'untranslated region, respectively. In addition, the data from whole-genome methylation sequencing and methylation-specific PCR indicated that the CpG island within miR-515-3p promoter was markedly hypermethylated in ESCC cell lines and ESCC tumor tissues, which may lead to deregulation of miR-515-3p expression in ESCC. Furthermore, our preclinical experiment provides solid evidence that systemic delivery of miR-515-3p oligonucleotide obviously suppressed the metastasis of ESCC cells in nude mice. Taken together, this study demonstrates that miR-515-3p suppresses tumor metastasis and thus represents a promising prognostic biomarker and therapeutic strategy in ESCC.

Extracellular Vesicles Loaded miRNAs as Potential Modulators Shared Between Glioblastoma, and Parkinson's and Alzheimer's Diseases

Glioblastoma (GBM) is the deadliest brain tumor. Its poor prognosis is due to cell heterogeneity, invasiveness, and high vascularization that impede an efficient therapeutic approach. In the past few years, several molecular links connecting GBM to neurodegenerative diseases (NDDs) were identified at preclinical and clinical level. In particular, giving the increasing critical role that epigenetic alterations play in both GBM and NDDs, we deeply analyzed the role of miRNAs, small non-coding RNAs acting epigenetic modulators in several key biological processes. Specific miRNAs, transported by extracellular vesicles (EVs), act as intercellular communication signals in both diseases. In this way, miRNA-loaded EVs modulate GBM tumorigenesis, as they spread oncogenic signaling within brain parenchyma, and control the aggregation of neurotoxic protein (Tau, Aβ-amyloid peptide, and α-synuclein) in NDDs. In this review, we highlight the most promising miRNAs linking GBM and NDDs playing a significant pathogenic role in both diseases.

HOX gene cluster (de)regulation in brain: from neurodevelopment to malignant glial tumours

HOX genes encode a family of evolutionarily conserved homeodomain transcription factors that are crucial both during development and adult life. In humans, 39 HOX genes are arranged in four clusters (HOXA, B, C, and D) in chromosomes 7, 17, 12, and 2, respectively. During embryonic development, particular epigenetic states accompany their expression along the anterior-posterior body axis. This tightly regulated temporal-spatial expression pattern reflects their relative chromosomal localization, and is critical for normal embryonic brain development when HOX genes are mainly expressed in the hindbrain and mostly absent in the forebrain region. Epigenetic marks, mostly polycomb-associated, are dynamically regulated at HOX loci and regulatory regions to ensure the finely tuned HOX activation and repression, highlighting a crucial epigenetic plasticity necessary for homeostatic development. HOX genes are essentially absent in healthy adult brain, whereas they are detected in malignant brain tumours, namely gliomas, where HOX genes display critical roles by regulating several hallmarks of cancer. Here, we review the major mechanisms involved in HOX genes (de)regulation in the brain, from embryonic to adult stages, in physiological and oncologic conditions. We focus particularly on the emerging causes of HOX gene deregulation in glioma, as well as on their functional and clinical implications.

miR-5188 augments glioma growth, migration and invasion through an SP1-modulated FOXO1-PI3K/AKT-c-JUN-positive feedback circuit

The biological effect and molecular mechanism of miR-5188 have not been thoroughly investigated. The study aims at elucidating the role of miR-5188 in glioma progression. Human glioma cell lines and tissues were used for functional and expression analysis. Cellular and molecular techniques were performed to explore the functions and mechanisms of miR-5188 in glioma. In our investigation, we demonstrated that miR-5188 promoted cell proliferation, the G1/S transition of the cell cycle, migration and invasion in glioma and reduced the lifespan of glioma-bearing mice. miR-5188 directly targeted FOXO1 and activated PI3K/AKT-c-JUN signalling, which enhanced miR-5188 expression. Moreover, the c-JUN transcription factor functionally bound to the miR-5188 promoter region, forming the positive feedback loop. The feedback loop promoted glioma progression through activating the PI3K/AKT signalling, and this loop is augmented by the interaction between SP1 and c-JUN. Moreover, it was also found that the miR-5188/FOXO1 axis is facilitated by SP1-activated PI3K/AKT/c-JUN signalling. In glioma samples, miR-5188 expression was found to be an unfavourable factor and was positively associated with the mRNA levels of SP1 and c-JUN, whereas negatively associated with the mRNA levels of FOXO1. Our investigation demonstrates that miR-5188 could function as a tumour promoter by directly targeting FOXO1 and participating in SP1-mediated promotion of cell growth and tumorigenesis in glioma.

LncRNA MALAT1 Promotes the Proliferation, Migration, and Invasion of Melanoma Cells by Downregulating miR-23a

Purpose

This study was designed to investigate the relationship between long-chain non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (lncRNA MALAT1)/miR-23a-23a and melanoma.

Patients and Methods

Fifty-two cases of corresponding non-tumor normal tissues and 109 cases (including 62 cases of primary melanoma and 47 cases of metastatic melanoma) were collected. Real-time fluorescent PCR quantified lncRNA MALAT1 and miR-23a, and counted the 3-year survival of high/low miR-23 and high/low lncRNA MALAT1 populations. We predicted the binding site according to the sequence information of lncRNA MALAT1 and miR-23a. lncRNA MALAT1 siRNA and miR-23a mimics vectors were constructed and transfected into melanoma cell lines respectively to observe their effects on cells.

Results

Compared with corresponding non-tumor normal tissues, lncRNA MALAT1 in melanoma tissue increased while miR-23a decreased. Compared with primary melanoma, metastatic melanoma was higher and miR-23a was lower. Downregulation of lncRNA MALAT1 caused upregulation of miR-23a, and lncRNA MALAT1 could bind to miR-23a. Downregulating lncRNA MALAT1 or upregulating miR-23a inhibited cell proliferation, migration and invasion and promoted apoptosis. Rescue experiments revealed that downregulation of miR-23a could offset cell changes caused by downregulation of lncRNA MALAT1.

Conclusion

lncRNA MALAT1 promotes malignant proliferation of melanoma cells through miR-23a.

MiRNA-7 Replacement Effect on Proliferation and Tarceva-Sensitivity in U373-MG Cell Line

BACKGROUND

Deregulation of the EGFR signaling pathway activity has been shown to can be effective in resistance to EGFR-TKIs, such as Tarceva (erlotinib), in glioblastoma cells. In addition, reports have shown that the reduction of miRNA-7 expression levels is associated with an increase in the expression of EGFR. Here, we evaluated the effect of miRNA-7 on EGFR expression and sensitivity of the U373-MG glioblastoma to erlotinib.

METHODS

The effect of miRNA-7 on EGFR expression was examined using RT-qPCR and western blotting. Trypan blue and MTT assays were performed to explore the effect of treatments on cell growth and survival, respectively. The combination index analysis was used to evaluate the interaction between drugs. Apoptosis was measured by ELISA cell death assay.

RESULTS

We showed that miRNA-7 markedly inhibited the expression of EGFR and decreased the growth of glioblastoma cells, relative to blank control and negative control miRNA (p < 0.05). Introduction of miRNA-7 synergistically increased the sensitivity of the U373-MG cells to erlotinib. Results of apoptosis assay demonstrated that miRNA-7 can trigger apoptosis and enhance the erlotinib-mediated apoptosis.

CONCLUSIONS

Our results show that miRNA-7 plays a critical role in the growth, survival and sensitivity of the U373-MG cells to erlotinib by targeting EGFR. Thus, miRNA-7 replacement therapy can become an effective therapeutic procedure in glioblastoma.

PTEN inhibition attenuates endothelial cell apoptosis in coronary heart disease via modulating the AMPK-CREB-Mfn2-mitophagy signaling pathway

Atherosclerosis (AS) is a major pathogenic factor in patients with cardiovascular diseases, and endothelial dysfunction (ED) plays a primary role in the occurrence and development of AS. In our study, we attempted to evaluate the role of phosphatase and tensin homolog (PTEN) in endothelial cell apoptosis under oxidized low-density lipoprotein (ox-LDL) stimulation and identify the associated mechanisms. The results of our study demonstrated that ox-LDL induced human umbilical vein endothelial cell (HUVEC) death via mitochondrial apoptosis, as evidenced by reduced mitochondrial potential, increased mitochondria permeability transition pore opening, cellular calcium overload, and caspase-9/-3 activation. In addition, ox-LDL also suppressed cellular energy production via downregulating the mitochondrial respiratory complex. Moreover, ox-LDL impaired HUVECs migration. Western blot analysis showed that PTEN expression was upregulated after exposure to ox-LDL and knockdown of PTEN could attenuate ox-LDL-mediated endothelial cell damage. Furthermore, we found that ox-LDL impaired mitophagy activity, whereas PTEN deletion could improve mitophagic flux and this effect relied on the activity of the AMP-activated protein kinase (AMPK)-cAMP-response element-binding protein (CREB)-Mitofusin-2 (Mfn2) axis. When the AMPK-CREB-Mfn2 pathway was inhibited, PTEN deletion-associated HUVECs protection was significantly reduced, suggesting that the AMPK-CREB-Mfn2-mitophagy axis is required for PTEN deletion-mediated endothelial cell survival under ox-LDL. Taken together, our results indicate that ox-LDL-induced endothelial cell damage is associated with PTEN overexpression, and inhibition of PTEN could promote endothelial survival via activating the AMPK-CREB-Mfn2-mitophagy signaling pathway.

Exosomes with low miR-34c-3p expression promote invasion and migration of non-small cell lung cancer by upregulating integrin α2β1

Exosomes play critical roles in regulating various physiological and pathological processes, including immune stimulation, immune suppression, cardiovascular diseases, and cancers. Recent studies show that exosomes that transport specific microRNAs (miRNAs) are involved in tumor development. However, the molecular mechanism by which tumor invasion and migration are regulated by exosomes from non-small cell lung cancer (NSCLC) is not well understood. Here, we show that exosomes shuttling low levels of miR-34c-3p are involved in NSCLC progression. Our results showed that exosomes derived from NSCLC cells carrying low levels of miR-34c-3p could be transported into the cytoplasm of NSCLC cells and accelerate NSCLC invasion and migration by upregulating integrin α2β1. A luciferase assay revealed that integrin α2β1 was the direct target of miR-34c-3p, and overexpression of integrin α2β1 could promote the invasion and migration of NSCLC cells. The analysis of exosomes derived from clinical serum samples indicated that the expression of miR-34c-3p was significantly downregulated in exosomes from NSCLC patients compared with that of normal controls. A549-derived exosomes promoted NSCLC cells lung metastases in vivo. Exosomes shuttling low levels of miR-34c-3p were associated with the progression of NSCLC in vitro and in vivo. Our data demonstrate that exosomes shuttling low levels of miR-34c-3p can accelerate the invasion and migration of NSCLC by upregulating integrin α2β1. MiR-34c-3p can be a diagnostic and prognostic marker for NSCLC. High expression of integrin α2β1 is positively related to the migration and metastasis of NSCLC cells.

MiR-652 serves as a prognostic biomarker in gastric cancer and promotes tumor proliferation, migration, and invasion via targeting RORA

PURPOSE

MicroRNAs (miRNAs) have been reported to be involved in tumorigenesis. The aim of this study was to investigate the functional role and prognostic value of miR-652 in gastric cancer (GC).

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine the expression levels of miR-652 in human GC tissue samples and GC cell lines. The Kaplan-Meier survival curves and Cox regression analysis were performed to measure the prognostic value of miR-652 in GC. The tumor cell proliferation capacity was estimated by MTT assay, and cell migration and invasion were assessed by Transwell assays. The luciferase reporter assay was performed to confirm the target gene of miR-652.

RESULTS

MiR-652 was significantly elevated in GC tissues and cell lines (all P< 0.001). And the expression level of miR-652 was significantly associated with TNM stage and lymph node metastasis (all P< 0.05). GC patients with high expression of miR-652 had a shorter overall survival rate than those with low miR-652 expression (log-rank P< 0.001). The miR-652 and TNM stage were proven to be independent prognostic predictors for the GC patients. Overexpressing miR-652 could enhance cell proliferation, migration and invasion (all P< 0.01). RORA was proved to be the target gene of miR-652.

CONCLUSION

MiR-652 functions as an oncogene in GC and promotes tumor progression via targeting RORA. MiR-652 might be a novel predictive marker for the poor prognosis of GC patients.

The effect of overexpression of the HOXD10 gene on the malignant proliferation, invasion, and tumor formation of pancreatic cancer cell PANC-1

Background

To determine the role of HOXD10 in pancreatic cancer.

Methods

A stable HOXD10-expressing PANC-1 cell line was established. Proliferation rates were detected by 5-Ethynyl-2'-deoxyuridine (Edu) staining while invasion was evaluated by Transwell assay. The expression levels of different proteins were analyzed by Western blotting. A subcutaneous xenograft of pancreatic cancer was established in nude mice, and the tumor weight and body weight were monitored. The in-situ expression of relevant markers in the tumor tissues was detected by immunohistochemistry.

Results

HOXD10 overexpression significantly decreased the proliferation rates of PANC-1 cells, and down-regulated Ki67 and Survivin (P<0.05). In addition, the invasive capacity (P<0.05) and the levels of vascular endothelial growth factor (VEGF) and MMP-14 were also significantly decreased (P<0.05) in the cells overexpressing HOXD10. Consistent with this, high levels of HOXD10 were associated with an increase in E-cadherin (P<0.05) and a decrease in N-cadherin (P<0.05) expression. Furthermore, the HOXD10-overexpressing xenografts were significantly smaller (P<0.05) and had fewer Ki67, VEGF, and N-cadherin-positive cells (P<0.05).

Conclusions

HOXD10 acts as a tumor suppressor in pancreatic cancer, and inhibits the proliferation, invasion, and epithelial-mesenchymal transition of the tumor cells.

Frequent promoter methylation of HOXD10 in endometrial carcinoma and its pathological significance

Homeobox D 10 (HOXD10) is important in cell differentiation and morphogenesis and serves as a tumor suppressor gene (TSG) in a number of malignancies. The present study investigated its promoter methylation status and association with the clinicopathological features of endometrial cancer (EC), and measured HOXD10 protein expression levels. EC samples (n=62), including 50 endometroid adenocarcinoma (EA) and 12 mucinous endometrial carcinoma samples (EC) and 70 non-cancerous samples were collected. All samples were evaluated for the methylation status of several TSGs, including HOXD10, using methylation-specific PCR. HOXD10 expression level was evaluated using immunohistochemistry. 5-Aza-2-deoxycytidine treatment was performed in the EC cell line Ishikawa to observe the change in HOXD10 expression levels. HOXD10 promoter methylation was more frequent in cancer samples (P<0.001). Downregulation of HOXD10 in EC samples was confirmed at the protein level using immunohistochemistry (P<0.001) and immunohistochemical staining was negatively associated with methylation status (P<0.05). Less HOXD10 protein was expressed in MEC compared with EA samples (P<0.001). The HOXD10 promoter was hypermethylated in both EA and MEC, causing decreased HOXD10 protein expression levels in EC cells. HOXD10 expression levels were partially reversed by 5-Aza-2-deoxycytidine treatment. The results of the present study demonstrated that epigenetic silencing of HOXD10 putatively contributed to the tumorigenesis of EA. Although there was no significant difference in HOXD10 methylation between EA and MEC, HOXD10 protein expression levels differed between these two diseases, indicating that it may be a useful protein biomarker for distinguishing between these two lesions.

Mief1 augments thyroid cell dysfunction and apoptosis through inhibiting AMPK-PTEN signaling pathway

Objective: Inflammation-mediated thyroid cell dysfunction and apoptosis increases the like-hood of hypothyroidism.Aim: Our aim in the present study is to explore the role of mitochondrial elongation factor 1 (Mief1) in thyroid cell dysfunction induced by TNFα.Materials and methods: Different doses of TNFα were used to incubate with thyroid cells in vitro. The survival rate, apoptotic index and proliferation capacity of thyroid cells were measured. Cellular energy metabolism and endoplasmic reticulum function related to protein synthesis were detected.Results: In response to TNFα treatment, the levels of Mief1 were increased, coinciding with a drop in the viability of thyroid cells in vitro. Loss of Mief1 attenuates TNFα-induced cell death through reducing the ratio of cell apoptosis. Further, we found that Mief1 deletion reversed cell energy metabolism and this effect was attributable to mitochondrial protection. Mief1 knockdown sustained mitochondrial membrane potential and reduced mitochondrial ROS overproduction. In addition, Mief1 knockdown also reduced endoplasmic reticulum stress, as evidenced by decreased levels of Chop and Caspase-12. Finally, our data verified that TNFα treatment inhibited the activity of AMPK-PTEN pathway whereas Mief1 deletion reversed the activity of AMPK and thus promoted the upregulation of PTEN. However, inhibition of AMPK-PTEN pathways could abolish the beneficial effects exerted by Mief1 deletion on thyroid cells damage and dysfunction.Conclusions: Altogether, our data indicate that immune abnormality-mediated thyroid cell dysfunction and death are alleviated by Mief1 deletion possible driven through reversing the activity of AMPK-PTEN pathways.

Chemical compound cinobufotalin potently induces FOXO1-stimulated cisplatin sensitivity by antagonizing its binding partner MYH9

In this study, we present novel molecular mechanisms by which FOXO1 functions as a tumor suppressor to prevent the pathogenesis of nasopharyngeal carcinoma (NPC). First, we observed that FOXO1 not only controlled tumor stemness and metastasis, but also sensitized NPC cells to cisplatin (DDP) in vitro and in vivo. Mechanistic studies demonstrated that FOXO1-induced miR-200b expression through the GSK3β/β-catenin/TCF4 network-mediated stimulation of ZEB1, which reduced tumor stemness and the epithelial-mesenchymal transition (EMT) signal. Furthermore, we observed FOXO1 interaction with MYH9 and suppression of MYH9 expression by modulating the PI3K/AKT/c-Myc/P53/miR-133a-3p pathway. Decreased MYH9 expression not only reduced its interactions with GSK3β, but also attenuated TRAF6 expression, which then decreased the ubiquitin-mediated degradation of GSK3β protein. Increased GSK3β expression stimulated the β-catenin/TCF4/ZEB1/miR-200b network, which increased the downstream tumor stemness and EMT signals. Subsequently, we observed that chemically synthesized cinobufotalin (CB) strongly increased FOXO1-induced DDP chemosensitivity by reducing MYH9 expression, and the reduction in MYH9 modulated GSK3β/β-catenin and its downstream tumor stemness and EMT signal in NPC. In clinical samples, the combination of low FOXO1 expression and high MYH9 expression indicated the worst overall survival rates. Our studies demonstrated that CB potently induced FOXO1-mediated DDP sensitivity by antagonizing its binding partner MYH9 to modulate tumor stemness in NPC.

Sirtuin 3 attenuates neuroinflammation-induced apoptosis in BV-2 microglia

In this study, we explored the upstream regulatory mechanisms underlying inflammation-induced mitochondrial dysfunction in microglial BV-2 cells. Our results demonstrate that Sirtuin 3 (Sirt3) expression was downregulated in response to LPS-induced neuroinflammation. In addition, overexpression of Sirt3 attenuated LPS-induced BV-2 cell death. Functional studies illustrated that Sirt3 overexpression promoted normal mitochondrial function and inhibited mitochondria-dependent apoptosis in LPS-treated BV-2 cells. At the molecular level, suppressor of ras val-2 (SRV2) promoted LPS-mediated mitochondrial damage by inducing mitochondrial fission. Sirt3 overexpression, which suppressed the transcription of SRV2 and thus suppressed mitochondrial fission, played an anti-apoptotic role in LPS-treated BV-2 cells. Furthermore, Sirt3 inhibited SRV2 expression via the Mst1-JNK pathway, and re-activation of this pathway abolished the protective effects of Sirt3 on mitochondrial damage and apoptosis. Taken together, our results indicate that Sirt3-induced, Mst1-JNK-SRV2 signaling pathway-dependent inhibition of mitochondrial fission protected against neuroinflammation-mediated cell damage in BV-2 microglia. Sirt3 might therefore be an effective treatment for neuroinflammation.

Cinobufotalin powerfully reversed EBV-miR-BART22-induced cisplatin resistance via stimulating MAP2K4 to antagonize non-muscle myosin heavy chain IIA/glycogen synthase 3β/β-catenin signaling pathway

Background

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-related tumor. The role of EBV-encoding miR-BART22 is still unclear in NPC. This study aimed to identify the detailed mechanisms by which EBV-miR-BART22 functions as a tumor-promoting factor and evaluate the action of cinobufotalin in treating EBV-miR-BART22-overexpressing NPC cells.

Methods

Using real-time PCR, western blotting, immunohistochemistry, and In situ hybridization, we detected the expression of miR-BART22 and MAP2K4 in tissues and cells, as well as evaluated their clinical relevance in NPC patients. The effects of miR-BART22 on cell metastasis, stemness and DDP chemoresistance were examined by sphere formation assay, side population analysis, transwell, boyden, in vivo xenograft tumor mouse model et al. Western blotting, immunofluorescence staining, luciferase reporter assay, ChIP, EMSA and Co-IP assay et al. were performed to explore the detailed molecular mechanism of EBV-miR-BART22 in NPC. Finally, we estimated the effects and molecular basis of Cinobufotalin on EBV-miR-BART22-overexpressing NPC cells in vitro and in vivo assays.

Findings

We observed that EBV-miR-BART22 not only promoted tumor stemness and metastasis, but also enhanced the resistance to Cisplatin (DDP) in vitro and in vivo. Mechanistic analysis indicated that EBV-miR-BART22 directly targeted the MAP2K4 and upregulated non-muscle myosin heavy chain IIA (MYH9) expression by PI3K/AKT/c-Jun-induced transcription. Further, MYH9 interacted with glycogen synthase 3β(GSK3β) protein and induced its ubiquitin degradation by activating PI3K/AKT/c-Jun-induced ubiquitin transcription and the latter combined with increased TRAF6 E3 ligase, which further bound to GSK3β protein. Reductions in the GSK3β protein thus promoted β-catenin expression and nuclear translocation, which induced tumor stemness and the epithelial-to-mesenchymal transition (EMT) signals. Furthermore, we observed that cinobufotalin, a new chemically synthesized compound, significantly suppressed EBV-miR-BART22-induced DDP chemoresistance by upregulating MAP2K4 to suppress MYH9/GSK3β/β-catenin and its downstream tumor stemness and EMT signals in NPC. Finally, clinical data revealed that increased miR-BART22 and reduced MAP2K4 expression caused the poor prognoses of NPC patients.

Interpretation

Our study provides a novel mechanism that cinobufotalin reversed the DDP chemoresistance and EMT induced by EBV-miR-BART22 in NPC.

MicroRNA-23a contributes to hippocampal neuronal injuries and spatial memory impairment in an experimental model of temporal lobe epilepsy

Temporal lobe epilepsy (TLE) is the most common form of epilepsy characterized by spontaneous recurrent seizures. It has been widely accepted that individuals with TLE tend to have neuronal injuries and memory impairment. However, little is known about the underlying molecular mechanisms. MicroRNAs (miRNAs) are small noncoding RNAs that regulate the expression of target genes at the posttranscriptional level. An increasing body of evidence suggests that miRNAs play pivotal roles in the pathogenesis of epilepsy. Here, we sought to determine the role of miR-23a, one of the most common miRNAs involved in various cancer types, in hippocampal neuronal injuries and spatial memory impairment in an experimental model of TLE. We found that miR-23a is upregulated in the hippocampus after status epilepticus (SE) in kanic acid (KA)-induced TLE mice. Furthermore, the upregulation of miR-23a is accompanied by hippocampal oxidative damage, neuronal injuries and spatial memory impairment in TLE mice. Inhibition of miR-23a expression by miR-23a antagomirs reduced hippocampal oxidative stress, neuronal injuries and improved spatial memory, while an increase in miR-23a expression by miR-23a agomir exacerbated hippocampal oxidative stress, neuronal injuries and spatial memory impairment in TLE mice. Our findings suggest that miR-23a contributes to hippocampal oxidative damage and neuronal injuries, which may consequently contribute to spatial memory impairment in TLE mice. Thus, targeting miR-23a in the epileptic brain may provide a novel strategy for protecting against hippocampal neuronal injuries and improving spatial memory in TLE patients.

MiR-145 inhibits EGF-induced epithelial-to-mesenchymal transition via targeting Smad2 in human glioblastoma

Background/Aims: MiR-145 and Smad2 have been widely reported in the development and progression of human malignancies. In the present study, we investigated the correlation between miR-145 and Smad2 in human glioblastoma multiforme (GBM).

Methods: The epithelial–mesenchymal transition (EMT) biomarkers and Smad2 were assessed by Western blot. The silencing of Smad2 was conducted by transfection of Smad2 siRNAs. The cell migration and invasion were evaluated using Transwell assays, respectively. The dual luciferase reporter assay was performed to identify whether Smad2 is a direct target of miR-145.

Results: The epidermal growth factor (EGF) activated the phosphorylation of Smad2 in U87 and U251 cells in a time- and dose-dependent manner. However, treatment with silencing of Smad2 or overexpression of miR-145 significantly inhibited the expressions of total Smad2, N-cadherin, Vimentin and matrix metallopeptidase 9, but induced the expression of E-cadherin. In addition, silencing of Smad2 or overexpression of miR-145 also inhibited the migration and invasion of U87 and U251 cells. Mechanistically, Smad2 was confirmed to be a target gene of miR-145 by bioinformatics analysis and luciferase reporter assay. Restored Smad2 expression also reversed miR-145-induced inhibition of EMT in U87 and U251 cells.

Conclusion: MiR-145 inhibits EGF-induced EMT via targeting Smad2 in human GBM. Therefore, miR-145 may be a promising biomarker and therapeutic target for GBM patients.