MiR-32 Inhibits Proliferation and Metastasis by Targeting EZH2 in Glioma

Long non-coding RNA SNHG17 contributes to the progression of pancreatic adenocarcinoma by modulating miR-32-5p/EZH2/STAT3 signaling

BACKGROUND

Adenocarcinoma of the pancreas (PAAD) is one of the most malignant tumors in the gastrointestinal tract. Long-chain noncoding RNAs (lncRNAs) are non-coding RNAs that are expressed in a variety of cancers. The purpose of this study is to study the expression, biology functions, and molecular mechanism of lncRNA SNHG17 in PAAD.

METHODS

In this study, qRT-PCR was used to measure the relative expression of SNHG17 and miR-32-5p in PAAD. In order to investigate the effect of SNHG17 and miR-32-5p on the proliferation, migration and invasion of PAAD cells, we performed a variety of tests including CCK-8, colony formation, scratch and transwell assays. Furthermore, SNHG17 and miR-32-5p interactions were confirmed by a luciferase reporter gene test.

RESULTS

Our results indicate that the expression of SNHG17 in PAAD is elevated, and in vitro studies have shown that SNHG17 enhances the proliferation of PAAD cells, Mechanistically, it has been shown that SNHG17 can direct target miR-32-5p in PAAD cells, thus promoting the proliferation of PAAD cells, migration, and invasion. Furthermore, SNHG17 has been found to activate EZH2/STAT3 signaling pathway through miR-32-5p in PAAD cells.

CONCLUSION

Our results show that SNHG17 plays a key role in the progression of PAAD by activating STAT3 signaling via regulation of miR-32-5p and EZH2.Identifying these new regulatory pathways may shed light on the underlying mechanism of PAAD and offer a potential therapeutic target for this fatal disease.

Overexpression of miR-32 in Chinese hamster ovary cells increases production of Fc-fusion protein

The demand for industrial genetically modified host cells were increased with the growth of the biopharmaceutical market. Numerous studies on improving host cell productivity have shown that altering host cell growth and viability through genetic engineering can increase recombinant protein production. During the last decades, it was demonstrated that overexpression or downregulation of some microRNAs in Chinese Hamster Ovary (CHO) cells as the host cell in biopharmaceutical manufacturing, can improve their productivity. The selection of microRNA targets has been based on their previously identified role in human cancers. MicroRNA-32 (miR-32), which is conserved between humans and hamsters (Crisetulus griseus), was shown to play a role in the regulation of cell proliferation and apoptosis in some human cancers. In this study, we investigated the effect of miR-32 overexpression on the productivity of CHO-VEGF-trap cells. Our results indicated that stable overexpression of miR-32 could dramatically increase the productivity of CHO cells by 1.8-fold. It also significantly increases cell viability, batch culture longevity, and cell growth. To achieve these results, following the construction of a single clone producing an Fc-fusion protein, we transfected cells with a pLexJRed-miR-32 plasmid to stably produce the microRNA and evaluate the impact of mir-32 overexpression on cell productivity, growth and viability in compare with scrambled control. Our findings highlight the application of miRNAs as engineering tools and indicated that miR-32 could be a target for engineering CHO cells to increase cell productivity.

FAM84B promotes the proliferation of glioma cells through the cell cycle pathways

Background

This study aimed to investigate FAM84B expression in glioma tissues and explore the role of FAM84B in promoting the proliferation of glioma cells and the mechanism of regulating the cell cycle pathways.

Methods

The TCGA database was adopted to analyze FAM84B expression in glioma tissues. The FAM84B expression was detected by qRT-PCR in patients with glioma, especially that in glioma cells, U251, LN-229, U98, and U87. Two glioma cell lines U87 and T98 were selected for siRNA transfection, which were divided into si-NC si-FAM84B-1 and si-FAM84B-2 groups. The effect of FAM84B on the proliferation of glioma cells was detected with the MTT experiment and that on the glioma cell cycle was detected with the flow cytometry. The signaling pathways potentially regulated by FAM84B in glioma were analyzed through the bioinformatics analysis. The expression of proteins, Cyclin D1, CDK4, Cdk6, and p21, in the cell cycle-related pathways in cells of each group was detected by the Western blot.

Results

TCGA database results showed a significantly higher FAM84B expression in glioma tissues than that in paracancerous tissues. According to the detection of qRT-PCR, FAM84B expressed the highest in the glioma cell line U87 (P < 0.05). Compared with the serum of healthy controls, FAM84B mRNA expression significantly increased in patients with gliomas. And compared with the si-NC group, the proliferation ability of U87 and T98 cells decreased and the cell cycle was blocked in the G0/G1 phase in both si-FAM84B transfection groups (P < 0.05). According to the bioinformatics analysis, FAM84B regulated the cell cycle pathways in glioma. FAM84B siRNA inhibited the expression of key proteins, Cyclin D1, CDK2, CDK4, and Cdk6, of the cell cycle pathways in glioma cells and promoted the expression of P53 and P21 proteins.

Conclusions

In conclusion, FAM84B may inhibit the proliferation of glioma cells by regulating the cell cycle pathways.

1. FAM84B expressed highly in glioma tissues and cells.

2. Knockdown of FAM84B expression significantly inhibited the proliferation of glioma cells.

3. Knockdown of FAM84B inhibited the proliferation of glioma cells by regulating the cell cycle signaling pathways.

Modulation of Small RNA Signatures by Astrocytes on Early Neurodegeneration Stages; Implications for Biomarker Discovery

Diagnosis of neurodegenerative disease (NDD) is complex, therefore simpler, less invasive, more accurate biomarkers are needed. small non-coding RNA (sncRNA) dysregulates in NDDs and sncRNA signatures have been explored for the diagnosis of NDDs, however, the performance of previous biomarkers is still better. Astrocyte dysfunction promotes neurodegeneration and thus derived scnRNA signatures could provide a more precise way to identify of changes related to NDD course and pathogenesis, and it could be useful for the dissection of mechanistic insights operating in NDD. Often sncRNA are transported outside the cell by the action of secreted particles such as extracellular vesicles (EV), which protect sncRNA from degradation. Furthermore, EV associated sncRNA can cross the BBB to be found in easier to obtain peripheral samples, EVs also inherit cell-specific surface markers that can be used for the identification of Astrocyte Derived Extracellular Vesicles (ADEVs) in a peripheral sample. By the study of the sncRNA transported in ADEVs it is possible to identify astrocyte specific sncRNA signatures that could show astrocyte dysfunction in a more simpler manner than previous methods. However, sncRNA signatures in ADEV are not a copy of intracellular transcriptome and methodological aspects such as the yield of sncRNA produced in ADEV or the variable amount of ADEV captured after separation protocols must be considered. Here we review the role as signaling molecules of ADEV derived sncRNA dysregulated in conditions associated with risk of neurodegeneration, providing an explanation of why to choose ADEV for the identification of astrocyte-specific transcriptome. Finally, we discuss possible limitations of this approach and the need to improve the detection limits of sncRNA for the use of ADEV derived sncRNA signatures.

H3F3A K27M Mutation Promotes the Infiltrative Growth of High-Grade Glioma in Adults by Activating β-Catenin/USP1 Signaling

Simple Summary

Gliomas is a primary type of tumor in the central nervous system. High-grade glioma is a malignant cancerous disease and grows rapidly. This study reports the expression of H3.3K27M in high-grade glioma tissues and the association with malignant glioma cell behavior. Moreover, the results suggested that a high expression of H3.3K27M promotes the migration and invasion of glioma cells, leading to a poor prognosis by promoting the infiltration of glioma through aggravating aberrant activation of β-catenin signaling-driven pathway.

Abstract

H3F3A K27M (H3.3K27M) is a newly identified molecular pathological marker in glioma and is strongly correlated with the malignancy of diffuse intrinsic pontine glioma (DIPG). In recent years, accumulating evidence has revealed that other types of glioma also contain the H3.3K27M mutation. However, the role of H3.3K27M in high-grade adult glioma, the most malignant glioma, has not been investigated. In this study, we focused on exploring the expression and function of H3.3K27M in high-grade glioma in adults. We found that H3.3K27M was highly expressed at high levels in some high-grade glioma tissues. Then, we introduced H3.3K27M into H3.3 wild-type glioma cells, U87 cells and LN229 cells. We found that H3.3K27M did not affect the growth of glioma cells in vitro and in vivo; however, the survival of mice with transplanted tumors was significantly reduced. Further investigation revealed that H3.3K27M expression mainly promoted the migration and invasion of glioma cells. Moreover, we confirmed that H3.3K27M overexpression increased the levels of the β-catenin and p-β-catenin (Ser675) proteins, the ubiquitin-specific protease 1 (USP1) mRNA and protein levels, and the enhancer of zeste homolog 2 (EZH2) protein level. In addition, the β-catenin inhibitor XAV-939 significantly attenuated the upregulation of the aforementioned proteins and inhibited the increased migration and invasion caused by the H3.3K27M mutation. Overall, the H3.3K27M mutation in high-grade glioma is a potential biomarker for poor prognosis mainly due to the infiltration of glioma cells that is at least partially mediated by the β-catenin/USP1/EZH2 pathway.

miR-1297 sensitizes glioma cells to temozolomide (TMZ) treatment through targeting adrenomedullin (ADM)

BACKGROUND

Gliomas account for about 80% of all malignant brain and other central nervous system (CNS) tumors. Temozolomide (TMZ) resistance represents a major treatment hurdle. Adrenomedullin (ADM) has been reported to induce glioblastoma cell growth.

METHODS

Cell viability was measured using the CCK-8 assay. The apoptosis analysis was performed using the Annexin V-FITC Apoptosis Detection Kit. The mitochondrial membrane potential was determined by JC-1 staining. A nude mouse tumor assay was used to detect tumor formation. Hematoxylin and eosin (H&E) and immunohistochemical (IHC) staining were performed in tissue sections. Activation of Akt and Erk and expression of apoptosis-related proteins were determined by immunoblotting.

RESULTS

ADM expression has been found upregulated in TMZ -resistant glioma samples based on bioinformatics and experimental analyses. Knocking down ADM in glioma cells enhanced the suppressive effects of TMZ on glioma cell viability, promotive effects on cell apoptosis, and inhibitory effects on mitochondrial membrane potential. Moreover, ADM knockdown also enhanced TMZ effects on Bax/Bcl-2, Akt phosphorylation, and Erk1/2 phosphorylation. Bioinformatics and experimental investigation indicated that miR-1297 directly targeted ADM and inhibited ADM expression. miR-1297 overexpression exerted similar effects to ADM knockdown on TMZ-treated glioma cells. More importantly, under TMZ treatment, inhibition of miR-1297 attenuated TMZ treatment on glioma cells; ADM knockdown partially attenuated the effects of miR-1297 inhibition on TMZ-treated glioma cells.

CONCLUSIONS

miR-1297 sensitizes glioma cells to TMZ treatment through targeting ADM. The Bax/Bcl-2, Akt, and Erk1/2 signaling pathways, as well as mitochondrial functions might be involved.

The long and short non-coding RNAs modulating EZH2 signaling in cancer

Non-coding RNAs (ncRNAs) are a large family of RNA molecules with no capability in encoding proteins. However, they participate in developmental and biological processes and their abnormal expression affects cancer progression. These RNA molecules can function as upstream mediators of different signaling pathways and enhancer of zeste homolog 2 (EZH2) is among them. Briefly, EZH2 belongs to PRCs family and can exert functional roles in cells due to its methyltransferase activity. EZH2 affects gene expression via inducing H3K27me3. In the present review, our aim is to provide a mechanistic discussion of ncRNAs role in regulating EZH2 expression in different cancers. MiRNAs can dually induce/inhibit EZH2 in cancer cells to affect downstream targets such as Wnt, STAT3 and EMT. Furthermore, miRNAs can regulate therapy response of cancer cells via affecting EZH2 signaling. It is noteworthy that EZH2 can reduce miRNA expression by binding to promoter and exerting its methyltransferase activity. Small-interfering RNA (siRNA) and short-hairpin RNA (shRNA) are synthetic, short ncRNAs capable of reducing EZH2 expression and suppressing cancer progression. LncRNAs mainly regulate EZH2 expression via targeting miRNAs. Furthermore, lncRNAs induce EZH2 by modulating miRNA expression. Circular RNAs (CircRNAs), like lncRNAs, affect EZH2 expression via targeting miRNAs. These areas are discussed in the present review with a focus on molecular pathways leading to clinical translation.

The Value of miR-296 and miR-517c in Evaluating the Prognosis of Patients with Glioma after Radiotherapy and Chemotherapy

Objective

To explore the value of miR-296 and miR-517c in evaluating the prognosis of patients with glioma after radiotherapy and chemotherapy.

Methods

732 patients with glioma were selected from January 2012 to January 2018. According to the effect of postoperative chemotherapy, the patients were divided into two groups: the effective group and the ineffective group. The serum miR-296, miR-517c, and clinicopathological parameters of the two groups before chemotherapy were compared. The factors affecting the sensitivity of radiotherapy and chemotherapy and the predictive efficacy of miR-296 and miR-517c on the prognosis of patients were analyzed.

Results

The expression level of miR-296 in glioma tissue was significantly correlated with tumor pathological grade and depth of invasion (P < 0.05), and the expression level of miR-296 in glioma tissue was significantly correlated with tumor pathological grade (P < 0.05). Logistic regression analysis showed that tumor size, WHO grade, and serum miR-296 and miR-517c levels were all factors affecting chemosensitivity (P < 0.05). The sensitivity, specificity, accuracy, and AUC of serum miR-296 prediction were 76.95%, 89.64%, 85.35%, and 0.891, respectively. The sensitivity, specificity, accuracy, and AUC of serum miR-517c prediction were 72.81%, 86.50%, 82.19%, and 0.739, respectively.

Conclusion

miR-296 and miR-517c are closely related to the chemosensitivity and prognosis of glioma patients. High levels of miR-296 and miR-517c can enhance chemosensitivity and serve as reliable indexes to predict the prognosis of patients with glioma.

EZH2 as a new therapeutic target in brain tumors: Molecular landscape, therapeutic targeting and future prospects

Brain tumors are responsible for high mortality and morbidity worldwide. The brain tumor treatment depends on identification of molecular pathways involved in progression and malignancy. Enhancer of zeste homolog 2 (EZH2) has obtained much attention in recent years in field of cancer therapy due to its aberrant expression and capacity in modulating expression of genes by binding to their promoter and affecting methylation status. The present review focuses on EZH2 signaling in brain tumors including glioma, glioblastoma, astrocytoma, ependymomas, medulloblastoma and brain rhabdoid tumors. EZH2 signaling mainly participates in increasing proliferation and invasion of cancer cells. However, in medulloblastoma, EZH2 demonstrates tumor-suppressor activity. Furthermore, EZH2 can regulate response of brain tumors to chemotherapy and radiotherapy. Various molecular pathways can function as upstream mediators of EZH2 in brain tumors including lncRNAs and miRNAs. Owing to its enzymatic activity, EZH2 can bind to promoter of target genes to induce methylation and affects their expression. EZH2 can be considered as an independent prognostic factor in brain tumors that its upregulation provides undesirable prognosis. Both anti-tumor agents and gene therapies such as siRNA have been developed for targeting EZH2 in cancer therapy.

Magic and mystery of microRNA-32

MicroRNAs (miRNAs) are a group of endogenous, small (∼22 nts in length) noncoding RNA molecules that function specifically by base pairing with the mRNA of genes and regulate gene expression at the post-transcriptional level. Alterations in miR-32 expression have been found in numerous diseases and shown to play a vital role in cell proliferation, apoptosis, oncogenesis, invasion, metastasis and drug resistance. MiR-32 has been documented as an oncomiR in the majority of related studies but has been also verified as a tumour suppressor miRNA in conflicting reports. Moreover, it has a crucial role in metabolic and cardiovascular disorders. This review provides an in-depth look into the most recent finding regarding miR-32, which is involved in the expression, regulation and functions in different diseases, especially tumours. Additionally, this review outlines novel findings suggesting that miR-32 may be useful as a noninvasive biomarker and as a targeted therapeutic in several diseases.

MicroRNA-199a-3p Exhibits Beneficial Effects in Asymptomatic Atherosclerosis by Inhibiting Vascular Smooth Muscle Cell Proliferation and Migration

Atherosclerosis (AS) is a serious healthy burden worldwide, it occurs accompany with the disfunction of vascular smooth muscle cells (VSMCs). MicroRNAs play pivotal role in the pathogenesis of various diseases. This study aimed to investigate the expression and clinical value of miR-199a-3p in patients with asymptomatic AS, and further explore its regulatory role on VSMCs biological function. Quantitative real-time PCR was used to estimate the expression of miR-199a-3p. Correlation of miR-199a-3p with carotid intima-media thickness (CIMT) and C-reactive protein (CRP) was evaluated by Pearson correlation coefficient. A receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic value of miR-199a-3p. Effects of miR-199a-3p on cell proliferation and migration in VSMCs were analyzed using cell-counting method and Transwell assay. Luciferase reporter assay was performed for the target gene analysis. Serum expression of miR-199a-3p was decreased in asymptomatic AS patients compared with the healthy controls. The negative correlations of miR-199a-3p with CIMT and CRP were obtained. The decreased miR-199a-3p was proved to have diagnostic accuracy with an area under the ROC curve (AUC) of 0.912, and was an independent predictor for the occurrence of asymptomatic AS. In VSMCs, overexpression of miR-199a-3p led to inhibited cell proliferation and migration, while the knockdown of miR-199a-3p resulted in the opposite results. SP1 was proved to be the target gene of miR-199a-3p. Taken together, downregulated expression of miR-199a-3p is a candidate diagnostic biomarker in the patients with asymptomatic AS. Overexpression of miR-199a-3p exists suppressive effects on VSMC proliferation and migration, indicating that miR-199a-3p may be a potential therapeutic target for AS treatment.

Role of microRNAs As Biomarkers in Sepsis-Associated Encephalopathy

Sepsis-associated encephalopathy (SAE) is a neurological complication of sepsis, characterized by brain dysfunction without any direct central nervous system infection. The diagnosis of SAE is currently a challenge. In fact, problems in making a diagnosis of SAE cause a great variability of incidence that can reach up to 70% of all septic patients. Even more, despite SAE is the most frequent type of encephalopathy occurring in critically ill patients, the molecular mechanisms that guide its progression have not been completely elucidated. On the other hand, miRNAs have proven to be excellent biomarkers for both diagnosis and prognosis, especially in brain pathologies because of their small size they can cross the blood–brain barrier easier than other biomolecules. The identification of new miRNAs as biomarkers may help to improve SAE diagnosis and prognosis and also to design new therapies for this clinical manifestation that produces diffuse cerebral dysfunction. This review is focused on SAE physiopathology and the need to have clear criteria for its diagnosis; thus, this work postulates some miRNA candidates to be used for SAE biomarkers because of their role in both, neurological damage and sepsis.

lncRNA MT1JP-overexpression abolishes the silencing of PTEN by miR-32 in hepatocellular carcinoma

Previous studies have shown that long non-coding RNA (lncRNA) MT1JP plays a role as a tumor suppressor in several types of cancer. The present study aimed to explore the role of MT1JP in hepatocellular carcinoma (HCC). Paired HCC and non-tumor tissues from 64 patients with HCC were subjected to RNA isolation and reverse transcription-quantitative PCR (RT-qPCR) to analyze the differential expression of MT1JP, microRNA (miR)-32 and phosphatase and tensin homolog (PTEN) in HCC. Cell transfections, followed by RT-qPCR and western blotting, were carried out to investigate the interactions among MT1JP, miR-32 and PTEN. The role of MT1JP, miR-32 and PTEN in regulating HCC cell proliferation was assessed using a Cell Counting Kit-8 assay. It was found that MT1JP was downregulated in HCC cancer tissues compared with that in non-cancer tissues. Survival analysis showed that patients with low MT1JP expression levels exhibited a significantly higher 5-year overall survival rate compared with patients with high MT1JP levels. The expression of MT1JP in HCC tissues was positively associated with PTEN and negatively associated with miR-32. Overexpression of MT1JP increased the expression levels of PTEN and decreased the expression levels of miR-32. Overexpression of miR-32 did not affect the expression of MT1JP but decreased the expression levels of PTEN and attenuated the effect of overexpression of MT1JP on the expression of PTEN. Overexpression of MT1JP and PTEN decreased the proliferation of HCC cells. Overexpression of miR-32 played an opposite role and attenuated the effects of overexpression of MT1JP. Therefore, MT1JP may upregulate PTEN by downregulating miR-32 to regulate HCC cell proliferation.

Rediscovering potential molecular targets for glioma therapy through the analysis of the cell of origin, microenvironment, and metabolism

Gliomas are the most common type of malignant brain tumors. Despite significant medical advances, gliomas remain incurable and are associated with high mortality. Although numerous biomarkers of diagnostic value have been identified and significant progress in the prognosis of the outcome has been made, the treatment has not been parallelly improved during the last three decades. This review summarizes and discusses three aspects of recent discoveries related to glioma, with the objective to highlight the advantages of glioma-specific drugs targeting the cell of origin, microenvironment, and metabolism. Given the heterogeneous nature of gliomas, various cell populations have been implicated as likely sources of the tumor. Depending on the mutation(s) acquired by the cells, it is believed that neuronal stem/progenitor cells, oligodendrocyte progenitor cells, mature neurons, and glial cells can initiate cell transformation into a malignant phenotype. The level of tumorigenicity appears to be inversely correlated with the maturation of a given cell population. The microenvironment of gliomas includes non-cancer cells such as immune cells, fibroblasts, and cells of blood vessels, as well as secreted molecules and the extracellular matrix, and all these components play a vital role during tumor initiation and progression. We will discuss in detail how the tumor microenvironment can stimulate and drive the transformation of non-tumor cell populations into tumor-supporting cells or glioma cells. Metabolic reprogramming is a key feature of gliomas and is thought to reflect the adaptation to the increased nutritional requirements of tumor cell proliferation, growth, and survival. Mutations in the IDH gene can shape metabolic reprogramming and may generate some vulnerabilities in glioma cells, such as abnormal lipid metabolism and sensitivity to endoplasmic reticulum stress (ERS). We will analyze the prominent metabolic features of malignant gliomas and the key pathways regulating glioma metabolism. This review is intended to provide a conceptual background for the development of glioma therapies based on the properties of tumor cell populations, microenvironment, and metabolism.

Alteration in Expression of miR-32 and FBXW7 Tumor Suppressor in Plasma Samples of Patients with T-cell Acute Lymphoblastic Leukemia

Background

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive and malignant neoplasm that arises from the hematopoietic T-cell precursors. Inactivation of FBXW7 gene is frequently observed in T-cell acute lymphoblastic leukemia, suggesting a significant tumor-suppressive role for FBXW7 in the pathobiology of this leukemia. Considering the role of microRNAs in cell proliferation and regulation of apoptosis, the aim of this study was to identify novel oncogenic microRNAs that suppress FBXW7 in patients with T-ALL.

Patients and Methods

The expression levels of two bioinformatically predicted microRNAs – miR-32 and miR-107 were compared in patients with T-ALL and a control group. A total of 80 plasma samples were subjected to RNA extraction, and the microRNA expression profiles were assessed by the RT-qPCR. The expression level of miR-103 was used as the endogenous reference for normalization of quantitative data.

Results

The plasma levels of miR-32 and miR-107 in patients with T-ALL were significantly higher (5.65, P < 0.001) and lower (0.432, P = 0.002), respectively. On the other hand, the expression levels of FBXW7 gene were significantly downregulated by –76.9 fold in T-ALL patients (P < 0.001). The results of the ROC curve analysis indicated that overexpression of miR-32 might be used to distinguish T-ALL patients with reasonable sensitivity and specificity.

Conclusion

miR-32 is considered as a novel oncomir that targets FBXW7 and might have a role in the etiology or progression of T-ALL. Furthermore, miR-32 can potentially serve as a non-invasive biomarker for detection of T-ALL.