miR-423-5p contributes to a malignant phenotype and temozolomide chemoresistance in glioblastomas

Role of Non-coding RNAs in the Response of Glioblastoma to Temozolomide

Chemotherapy and radiotherapy are widely used in clinical practice across the globe as cancer treatments. Intrinsic or acquired chemoresistance poses a significant problem for medical practitioners and researchers, causing tumor recurrence and metastasis. The most dangerous kind of malignant brain tumor is called glioblastoma multiforme (GBM) that often recurs following surgery. The most often used medication for treating GBM is temozolomide chemotherapy; however, most patients eventually become resistant. Researchers are studying preclinical models that accurately reflect human disease and can be used to speed up drug development to overcome chemoresistance in GBM. Non-coding RNAs (ncRNAs) have been shown to be substantial in regulating tumor development and facilitating treatment resistance in several cancers, such as GBM. In this work, we mentioned the mechanisms of how different ncRNAs (microRNAs, long non-coding RNAs, circular RNAs) can regulate temozolomide chemosensitivity in GBM. We also address the role of these ncRNAs encapsulated inside secreted exosomes.

Exosomal miR-423-5p Derived from Cerebrospinal Fluid Pulsation Stress-Stimulated Osteoblasts Improves Angiogenesis of Endothelial Cells via DUSP8/ERK1/2 Signaling Pathway

Exosomes secreted from osteoblasts (OBs) can regulate the angiogenesis of endothelial cells (ECs); however, whether cerebrospinal fluid pulsation (CSFP) stress, a special mechanical stimulation, can influence the cell's communication in the context of angiogenesis remains unknown. In this study, the effect of exosomes derived from CSFP stress-stimulated OBs on facilitating the angiogenesis of ECs was investigated. First, OBs were cultured in a CSFP bioreactor, and exosomes derived from OBs were isolated and identified. Cell Counting Kit 8 assay, transwell migration assay, wound healing migration assay, and tube formation assay were conducted to assess the effects of CSFP stress-stimulated OBs-derived exosomes (CSFP-Exos) on the angiogenesis of ECs. Then high-throughput RNA sequencing was used to determine the miRNA profiles of Non-CSFP stress-stimulated OBs-derived exosomes (NCSFP-Exos) and CSFP-Exos, and the luciferase reporter gene assay was performed to confirm the binging of miR-423-5p to DUSP8. In addition, the Matrigel plug assay was performed to explore whether exosomal miR-423-5p has the same effects in vivo. Our results suggested that CSFP-Exos can promote the angiogenesis of ECs, and miR-423-5p was enriched in CSFP-Exos. Moreover, miR-423-5p could promote the effect of angiogenesis via directly targeting dual-specificity phosphatase 8 (DUSP8), which inhibited the ERK1/2 signaling pathway. In conclusion, exosomal miR-423-5p derived from CSFP stress-stimulated OBs could promote the angiogenesis of ECs by the DUSP8/ERK1/2 signaling pathway.

MicroRNAs in adult high-grade gliomas: Mechanisms of chemotherapeutic resistance and their clinical relevance

Notorious for its high mortality rate, the current standard treatment for high-grade gliomas remains a challenge. This is largely due to the complex heterogeneity of the tumour coupled with dysregulated molecular mechanisms leading to the development of drug resistance. In recent years, microRNAs (miRNAs) have been considered to provide important information about the pathogenesis and prognostication of gliomas. miRNAs have been shown to play a specific role in promoting oncogenesis and regulating resistance to anti-glioma therapeutic agents through diverse cellular mechanisms. These include regulation of apoptosis, alterations in drug efflux pathways, enhanced activation of oncogenic signalling pathways, Epithelial-Mesenchymal Transition-like process (EMT-like) and a few others. With this knowledge, upregulation or inhibition of selected miRNAs can be used to directly affect drug resistance in glioma cells. Moreover, the clinical use of miRNAs in glioma management is becoming increasingly valuable. This comprehensive review delves into the role of miRNAs in drug resistance in high-grade gliomas and underscores their clinical significance. Our analysis has identified a distinct cluster of oncogenic miRNAs (miR-9, miR-21, miR-26a, miR-125b, and miR-221/222) and tumour suppressive miRNAs (miR-29, miR-23, miR-34a-5p, miR 181b-5p, miR-16-5p, and miR-20a) that consistently emerge as key players in regulating drug resistance across various studies. These miRNAs have demonstrated significant clinical relevance in the context of resistance to anti-glioma therapies. Additionally, the clinical significance of miRNA analysis is emphasised, including their potential to serve as clinical biomarkers for diagnosing, staging, evaluating prognosis, and assessing treatment response in gliomas.

The role of exo-miRNA in diagnosis and treatment of cancers, focusing on effective miRNAs in colorectal cancer

Small extracellular (EV) particles known as exosomes are released by a variety of cell types, including immune system cells, stem cells, and tumor cells. They are regarded as a subgroup of EVs and have a diameter that ranges from 30 to 150 nm. Proteins, lipids, nucleic acids (including RNA and DNA), and different bioactive compounds are among the wide range of biomolecules that make up the cargo of exosomes. Exosomes are crucial for intercellular communication because they let cells share information and signaling chemicals. They are involved in various physiological and pathological processes, including immune responses, tissue regeneration, cancer progression, and neurodegenerative diseases. In conclusion, it is essential to continue research into exosome-based cancer medicines to advance understanding, improve treatment plans, create personalized tactics, ensure safety, and speed up clinical translation.

CVD phenotyping in oncologic disorders: cardio-miRNAs as a potential target to improve individual outcomes in revers cardio-oncology

With the increase of aging population and prevalence of obesity, the incidence of cardiovascular disease (CVD) and cancer has also presented an increasing tendency. These two different diseases, which share some common risk factors. Relevant studies in the field of reversing Cardio-Oncology have shown that the phenotype of CVD has a significant adverse effect on tumor prognosis, which is mainly manifested by a positive correlation between CVD and malignant progression of concomitant tumors. This distal crosstalk and the link between different diseases makes us aware of the importance of diagnosis, prediction, management and personalized treatment of systemic diseases. The circulatory system bridges the interaction between CVD and cancer, which suggests that we need to fully consider the systemic and holistic characteristics of these two diseases in the process of clinical treatment. The circulating exosome-miRNAs has been intrinsically associated with CVD -related regulation, which has become one of the focuses on clinical and basic research (as biomarker). The changes in the expression profiles of cardiovascular disease-associated miRNAs (Cardio-miRNAs) may adversely affect concomitant tumors. In this article, we sorted and screened CVD and tumor-related miRNA data based on literature, then summarized their commonalities and characteristics (several important pathways), and further discussed the conclusions of Cardio-Oncology related experimental studies. We take a holistic approach to considering CVD as a risk factor for tumor malignancy, which provides an in-depth analysis of the various regulatory mechanisms or pathways involved in the dual attribute miRNAs (Cardio-/Onco-miRNAs). These mechanisms will be key to revealing the systemic effects of CVD on tumors and highlight the holistic nature of different diseases. Therefore, the Cardio-miRNAs should be given great attention from researchers in the field of CVD and tumors, which might become new targets for tumor treatment. Meanwhile, based on the principles of precision medicine (such as the predictive preventive personalized medicine, 3PM) and reverse Cardio-oncology to better improve individual outcomes, we should consider developing personalized medicine and systemic therapy for cancer from the perspective of protecting cardiovascular function.

Epigenetic regulation of temozolomide resistance in human cancers with an emphasis on brain tumors: Function of non-coding RNAs

Brain tumors, which are highly malignant, pose a significant threat to health and often result in substantial rates of mortality and morbidity worldwide. The brain cancer therapy has been challenging due to obstacles such as the BBB, which hinders effective delivery of therapeutic agents. Additionally, the emergence of drug resistance further complicates the management of brain tumors. TMZ is utilized in brain cancer removal, but resistance is a drawback. ncRNAs are implicated in various diseases, and their involvement in the cancer is particularly noteworthy. The focus of the current manuscript is to explore the involvement of ncRNAs in controlling drug resistance, specifically in the context of resistance to the chemotherapy drug TMZ. The review emphasizes the function of ncRNAs, particularly miRNAs, in modulating the growth and invasion of brain tumors, which significantly influences their response to TMZ treatment. Through their interactions with various molecular pathways, miRNAs are modulators of TMZ response. Similarly, lncRNAs also associate with molecular pathways and miRNAs, affecting the efficacy of TMZ chemotherapy. Given their functional properties, lncRNAs can either induce or suppress TMZ resistance in brain tumors. Furthermore, circRNAs, which are cancer controllers, regulate miRNAs by acting as sponges, thereby impacting the response to TMZ chemotherapy. The review explores the correlation between ncRNAs and TMZ chemotherapy, shedding light on the underlying molecular pathways involved in this process.

miR-224-5p acts as a tumour suppressor and reverses the resistance to BRAF inhibitor in melanoma through directly targeting PAK4 to block the MAPK pathway

miR-224-5p has been shown to play both an oncogene and tumour suppressor role in many human tumours. However, the role and molecular mechanism of miR-224-5p in cutaneous melanoma remains unclear. miR-224-5p levels were downregulated in melanoma tissue, and low miR-224-5p expression was an independent risk factor for melanoma patients. miR-224-5p blocked proliferation, epithelial-to-mesenchymal transition (EMT), invasion, migration in BRAF wild-type melanoma cell, and overcome acquired BRAFi resistance in VMF-resistant melanoma cells. miR-224-5p exerted its role by directly repressing PAK4 to block the downstream CRAF/MEK/ERK pathways. We demonstrated that miR-224-5p inhibited melanoma growth and metastasis in vivo though xenograft tumor and pulmonary metastasis assay. Thus, miR-224-5p/PAK4-mediated CRAF/MEK/ERK pathways have therapeutic potential in melanoma treatment.

MiR-423-5p is a novel endogenous control for the quantification of circulating miRNAs in human esophageal squamous cell carcinoma

Circulating miRNA expression is most commonly measured by qRT-PCR, however, the lack of a suitable endogenous control hinders people from evaluating the accurate changes in miRNA expression levels and developing the non-invasive biomarkers. In this study, we aimed to screen the specific, highly stable endogenous control in esophageal squamous cell carcinoma (ESCC) to overcome the obstacle. We selected "housekeeping" miRNAs according to the published database and initially acquired 21 miRNAs. Subsequently, we screened these miRNAs using GSE106817 and TCGA datasets according to specific inclusion criteria and evaluated the suitability of "candidate" miRNAs. Among these miRNAs, the average abundance of miR-423-5p was relatively high in serum. Notably, miR-423-5p expression in serum showed no significant difference between ESCC patients and healthy controls (n = 188, P = 0.29). Moreover, among these miRNAs, miR-423-5p was the most stable miRNA using the NormFinder algorithms. Overall, these results indicate that miR-423-5p, as a novel and optimal endogenous control, could be used to quantify circulating miRNAs in ESCC.

A Proteomic Approach Reveals That miR-423-5p Modulates Glucidic and Amino Acid Metabolism in Prostate Cancer Cells

Recently, we have demonstrated that miR-423-5p modulates the growth and metastases of prostate cancer (PCa) cells both in vitro and in vivo. Here, we have studied the effects of miR-423-5p on the proteomic profile in order to identify its intracellular targets and the affected pathways. Applying a quantitative proteomic approach, we analyzed the effects on the protein expression profile of miR-423-5p-transduced PCa cells. Moreover, a computational analysis of predicted targets of miR-423-5p was carried out by using several target prediction tools. Proteomic analysis showed that 63 proteins were differentially expressed in miR-423-5-p-transfected LNCaP cells if compared to controls. Pathway enrichment analysis revealed that stable overexpression of miR-423-5p in LNCaP PCa cells induced inhibition of glycolysis and the metabolism of several amino acids and a parallel downregulation of proteins involved in transcription and hypoxia, the immune response through Th17-derived cytokines, inflammation via amphorin signaling, and ion transport. Moreover, upregulated proteins were related to the S phase of cell cycle, chromatin modifications, apoptosis, blood coagulation, and calcium transport. We identified seven proteins commonly represented in miR-423-5p targets and differentially expressed proteins (DEPs) and analyzed their expression and influence on the survival of PCa patients from publicly accessible datasets. Overall, our findings suggest that miR-423-5p induces alterations in glucose and amino acid metabolism in PCa cells paralleled by modulation of several tumor-associated processes.

MicroRNAs, Key Regulators in Glioma Progression as Potential Therapeutic Targets for Chinese Medicine

Gliomas are tumors of the primary central nervous system associated with poor prognosis and high mortality. The 5-year survival rate of patients with gliomas received surgery combined with chemotherapy or radiotherapy does not exceed 5%. Although temozolomide is commonly used in the treatment of gliomas, the development of resistance limits its use. MicroRNAs are non-coding RNAs involved in numerous processes of glioma cells, such as proliferation, migration and apoptosis. MicroRNAs regulate cell cycle, PI3K/AKT signal pathway, and target apoptosis-related genes (e.g., BCL6), angiogenesis-related genes (e.g., VEGF) and other related genes to suppress gliomas. Evidence illustrates that microRNAs can regulate the sensitivity of gliomas to temozolomide, cisplatin, and carmustine, thereby enhancing the efficacy of these agents. Moreover, traditional Chinese medicine (e.g., tanshinone IIA, xanthohumol, and curcumin) exert antiglioma effects by regulating the expression of microRNAs, and then microRNAs inhibit gliomas through influencing the process of tumors by targeting certain genes. In this paper, the mechanisms through which microRNAs regulate the sensitivity of gliomas to therapeutic drugs are described, and traditional Chinese medicine that can suppress gliomas through microRNAs are discussed. This review aims to provide new insights into the traditional Chinese medicine treatment of gliomas.

Lupus nephritis: The regulatory interplay between epigenetic and MicroRNAs

MicroRNAs (miRNAs) are endogenous, small, non-coding RNA molecules that act as epigenetic modifiers to regulate the protein levels of target messenger RNAs without altering their genetic sequences. The highly complex role of miRNAs in the epigenetics of lupus nephritis (LN) is increasingly being recognized. DNA methylation and histone modifications are focal points of epigenetic research. miRNAs play a critical role in renal development and physiology, and dysregulation may result in abnormal renal cell proliferation, inflammation, and fibrosis of the kidneys in LN. However, epigenetic and miRNA-mediated regulation are not mutually exclusive. Further research has established a link between miRNA expression and epigenetic regulation in various disorders, including LN. This review summarizes the most recent evidence regarding the interaction between miRNAs and epigenetics in LN and highlights potential therapeutic and diagnostic targets.

Inhibition of miR-423-5p Exerts Neuroprotective Effects in an Experimental Rat Model of Cerebral Ischemia/Reperfusion Injury

MicroRNAs (miRNAs) are widely acknowledged to play a unique role in cerebrovascular disease. This research investigates the function of microRNAs in ischemic stroke via a middle cerebral artery occlusion (MCAO) model. Four differentially expressed microRNAs in rat brains were identified by bioinformatics analysis, and qRT-PCR showed that miR-423-5p exhibited the highest expression in cerebral ischemia/reperfusion injury in rats, with peak levels observed at 24 hours. After microRNA inhibitors and mimics were administrated in the rat model of MCAO, the neurological scores and brain water content were detected, and triphenyltetrazolium chloride (TTC), Hematoxylin and Eosin (H&E), and Nissl staining were conducted to explore the influence of miR-423-5p on ischemic stroke. Subsequently, western blot, ELISA, MPO, TUNEL and commercial assay kits were applied to assess the influence of miR-423-5p on NLRP3 inflammasome, apoptosis, and oxidative stress levels in ischemic penumbra tissue. The results showed that miR-423-5p knockdown could effectively improve neurological indicators, such as cerebral infarct volume, brain water content, neurological scores, and nerve tissue damage, and inhibit the NLRP3 inflammasome, apoptosis, and oxidative stress. In contrast, the miR-423-5p mimic yielded opposite results. In conclusion, inhibition of miR-423-5p expression could effectively attenuate ischemic stroke and might be considered a promising target for stroke.

MicroRNAs as prognostic markers and therapeutic targets in gliomas

Gliomas are invasive brain tumors characterized by high rates of recurrence and mortality. Glioblastoma (GBM), a grade IV brain tumor, is known for its heterogenicity and its resistance to the current treatment regimen. MicroRNA (miRNAs) are small non-coding sequences of RNA that regulate and influence the expression of multiple genes. The detection of certain types of micro-RNA in tissues and blood serum can be used for diagnosis and prognosis, including the response of a particular patient to therapy. The purpose of this review is to analyze studies and experimental results concerning changes in microRNA expression profiles characteristic of gliomas. Furthermore, miRNAs also contribute to autophagy at multiple stages. In this review, we summarize the functions of miRNAs in GBM pathways linked to dysregulation of cell cycle control, apoptosis and resistance to treatment, and the possible use of miRNAs in clinical settings as treatment and prediction biomarkers.

A B7-CD28 Family-Based Signature Demonstrates Significantly Different Prognosis and Immunological Characteristics in Diffuse Gliomas

The B7-CD28 gene family plays a crucial role in modulating immune functions and has served as potential targets for immunotherapeutic strategies. Therefore, we systematically analyzed B7-CD28 family gene expression profiles and constructed a B7-CD28 family-based prognostic signature to predict survival and immune host status in diffuse gliomas. The TCGA dataset was used as a training cohort, and three CGGA datasets (mRNAseq_325, mRNAseq_693 and mRNA-array) were employed as validation cohorts to intensify the findings that we have revealed in TCGA dataset. Ultimately, we developed a B7-CD28 family-based signature that consisted of CD276, CD274, PDCD1LG2 and CD80 using LASSO Cox analysis. This gene signature was validated to have significant prognostic value, and could be used as a biomarker to distinguish pathological grade and IDH mutation status in diffuse glioma. Additionally, we found that the gene signature was significantly related to intensity of immune response and immune cell population, as well as several other important immune checkpoint genes, holding a great potential to be a predictive immune marker for immunotherapy and tumor microenvironment. Finally, a B7-CD28 family-based nomogram was established to predict patient life expectancy contributing to facilitate personalizing therapy for tumor sufferers. In summary, this is the first mathematical model based on this gene family with the aim of providing novel insights into immunotherapy for diffuse glioma.

The Role of microRNAs in Multidrug Resistance of Glioblastoma

Glioblastoma (GBM) is an aggressive brain tumor that develops from neuroglial stem cells and represents a highly heterogeneous group of neoplasms. These tumors are predominantly correlated with a dismal prognosis and poor quality of life. In spite of major advances in developing novel and effective therapeutic strategies for patients with glioblastoma, multidrug resistance (MDR) is considered to be the major reason for treatment failure. Several mechanisms contribute to MDR in GBM, including upregulation of MDR transporters, alterations in the metabolism of drugs, dysregulation of apoptosis, defects in DNA repair, cancer stem cells, and epithelial-mesenchymal transition. MicroRNAs (miRNAs) are a large class of endogenous RNAs that participate in various cell events, including the mechanisms causing MDR in glioblastoma. In this review, we discuss the role of miRNAs in the regulation of the underlying mechanisms in MDR glioblastoma which will open up new avenues of inquiry for the treatment of glioblastoma.

Immunomodulatory Properties of Human Breast Milk: MicroRNA Contents and Potential Epigenetic Effects

Infants who are exclusively breastfed in the first six months of age receive adequate nutrients, achieving optimal immune protection and growth. In addition to the known nutritional components of human breast milk (HBM), i.e., water, carbohydrates, fats and proteins, it is also a rich source of microRNAs, which impact epigenetic mechanisms. This comprehensive work presents an up-to-date overview of the immunomodulatory constituents of HBM, highlighting its content of circulating microRNAs. The epigenetic effects of HBM are discussed, especially those regulated by miRNAs. HBM contains more than 1400 microRNAs. The majority of these microRNAs originate from the lactating gland and are based on the remodeling of cells in the gland during breastfeeding. These miRNAs can affect epigenetic patterns by several mechanisms, including DNA methylation, histone modifications and RNA regulation, which could ultimately result in alterations in gene expressions. Therefore, the unique microRNA profile of HBM, including exosomal microRNAs, is implicated in the regulation of the genes responsible for a variety of immunological and physiological functions, such as FTO, INS, IGF1, NRF2, GLUT1 and FOXP3 genes. Hence, studying the HBM miRNA composition is important for improving the nutritional approaches for pregnancy and infant's early life and preventing diseases that could occur in the future. Interestingly, the composition of miRNAs in HBM is affected by multiple factors, including diet, environmental and genetic factors.

MicroRNA-218-5p affects lung adenocarcinoma progression through targeting endoplasmic reticulum oxidoreductase 1 alpha

Lung adenocarcinoma (LUAD) severely threatens the health of people owing to its lethality. Nonetheless, the underlying mechanisms on LUAD development remain unclear to a great extent. This work aimed to probe the functions of miR-218-5p in LUAD. MiR-218-5p and endoplasmic reticulum oxidoreductase 1 alpha (ERO1A) were screened as differently downregulated and upregulated RNAs in LUAD, respectively, by bioinformatics analyses. The results of cell functional assays stated that enforced expression of miR-218-5p notably restrained cell viability, invasion, and migration in LUAD. MiR-218-5p may interact with 3’-untranslated region of ERO1A mRNA as analyzed by bioinformatics. Afterward, western blot and dual-luciferase reporter gene analyses were introduced to identify their interaction. ERO1A overexpression reversed the suppressive impacts of miR-218-5p on LUAD cell progression, indicating the implication of miR-218-5p/ERO1A axis in suppressing cancer development. We also observed that this regulatory axis suppressed angiogenesis in LUAD. Taken together, miR-218-5p/ERO1A axis exerted an imperative role in LUAD cell progression, which provides a valuable clue for the development of LUAD therapeutic regimen.

Long non-coding RNA LINC00680 functions as a ceRNA to promote esophageal squamous cell carcinoma progression through the miR-423-5p/PAK6 axis

Background

Esophageal squamous cell carcinoma (ESCC) is a common invasive malignancy worldwide with poor clinical outcomes. Increasing amount of long non-coding RNAs (lncRNAs) have been reported to be involved in cancer development. However, lncRNAs that are functional in ESCC and the underlying molecular mechanisms remain largely unknown.

Methods

Transcriptomic analysis was performed to identify dysregulated lncRNAs in ESCC tissue samples. The high expression of LINC00680 in ESCC was validated by RT-qPCR, and the oncogenic functions of LINC00680 was investigated by cell proliferation, colony formation, migration and invasion assays in ESCC cells in vitro and xenografts derived from ESCC cells in mice. RNA-seq, competitive endogenous RNA (ceRNA) network analysis, and luciferase reporter assays were carried out to identify LINC00680 target genes and the microRNAs (miRNAs) bound to LINC00680. Antisense oligonucleotides (ASOs) were used for in vivo treatment.

Results

Transcriptome profiling revealed that a large number of lncRNAs was dysregulated in ESCC tissues. Notably, LINC00680 was highly expressed, and upregulation of LINC00680 was associated with large tumor size, advanced tumor stage, and poor prognosis. Functionally, knockdown of LINC00680 restrained ESCC cell proliferation, colony formation, migration, and invasion in vitro and inhibited tumor growth in vivo. Mechanistically, LINC00680 was found to act as a ceRNA by sponging miR-423-5p to regulate PAK6 (p21-activated kinase 6) expression in ESCC cells. The cell viability and motility inhibition induced by LINC00680 knockdown was significantly reversed upon PAK6 restoration and miR-423-5p inhibition. Furthermore, ASO targeting LINC00680 substantially suppressed ESCC both in vitro and in vivo.

Conclusions

An oncogenic lncRNA, LINC00680, was identified in ESCC, which functions as a ceRNA by sponging miR-423-5p to promote PAK6 expression and ESCC. LINC00680/miR-423-5p/PAK6 axis may serve as promising diagnostic and prognostic biomarkers and therapeutic targets for ESCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-022-01539-3.

MiR-423-5p prevents MALAT1-mediated proliferation and metastasis in prostate cancer

BACKGROUND

The long non-coding RNA (lncRNA), MALAT1, plays a key role in the development of different cancers, and its expression is associated with worse prognosis in patients. However, its mechanism of action and its regulation are not well known in prostate cancer (PCa). A general mechanism of action of lncRNAs is their interaction with other epigenetic regulators including microRNAs (miRNAs).

METHODS

Using lentiviral stable miRNA transfection together with cell biology functional assays and gene expression/target analysis, we investigated the interaction between MALAT1 and miR-423-5p, defined as a target with in silico prediction analysis, in PCa.

RESULTS

Through bioinformatic analysis of data available from TCGA, we have found that MALAT1 expression correlates with high Gleason grade, metastasis occurrence, and reduced survival in PCa patients. These findings were validated on a TMA of PCa showing a significant correlation between MALAT1 expression with both stage and grading. We report that, in PCa cells, MALAT1 expression and activity is regulated by miR-423-5p that binds MALAT1, downregulates its expression and inhibits its activity in promoting proliferation, migration, and invasion. Using NanoString analysis, we unraveled downstream cell pathways that were affected by miR-423-5p expression and MALAT1 downregulation and identified several alterations in genes that are involved in metastatic response and angiogenic pathways. In addition, we showed that the overexpression of miR-423-5p increases survival and decreases metastases formation in a xenograft mouse model.

CONCLUSIONS

We provide evidence on the role of MALAT1 in PCa tumorigenesis and progression. Also, we identify a direct interaction between miR-423-5p and MALAT1, which results in the suppression of MALAT1 action in PCa.

Genetic Variation in MicroRNA-423 Promotes Proliferation, Migration, Invasion, and Chemoresistance in Breast Cancer Cells

MicroRNA-423 (miR-423) is highly expressed in breast cancer (BC). Previously, our group showed that the SNP rs6505162:C>A located in the pre-miR-423 was significantly associated with increased familial BC risk in patients with a strong family history of BC. Therefore, in this study, we evaluated the functional role of rs6505162 in mammary tumorigenesis in vitro to corroborate the association of this SNP with BC risk. We found that rs6505162:C>A upregulated expression of both mature miR-423 sequences (3p and 5p). Moreover, pre-miR-423-A enhanced proliferation, and promoted cisplatin resistance in BC cell lines. We also showed that pre-miR-423-A expression decreased cisplatin-induced apoptosis, and increased BC cell migration and invasion. We propose that the rs6505162-A allele promotes miR-423 overexpression, and that the rs6505162-A allele induces BC cell proliferation, viability, chemoresistance, migration, and invasion, and decreases cell apoptosis as a consequence. We suggest that rs6505162:C>A is a functional SNP site with potential utility as a marker for early diagnosis, prognosis, and treatment efficacy monitoring in BRCA1/2-negative BC patients, as well as a possible therapeutic target.

MiR-423-5p activated by E2F1 promotes neovascularization in diabetic retinopathy by targeting HIPK2

BACKGROUND

Diabetic retinopathy (DR) is a diabetic complication and the primary cause of blindness in the world. However, the treatments of DR are challenging given its complicated pathogenesis. Here, we investigated the molecular mechanisms of DR by focusing on the function of E2F1/miR-423-5p/HIPK2/HIF1α/VEGF axis.

METHODS

Cultured retinal endothelial cells (hRMECs, hRECs) were treated with 25 mM glucose to mimic the high glucose-induced DR in vitro. Streptozotocin (STZ) was injected into mice to induce DR in mice. qRT-PCR, western blotting, immunohistochemistry, and ELISA were employed to measure levels of E2F1, miR-423-5p, HIPK2, HIF1α, and VEGF. H&E staining was utilized to examine retinal neovascularization. CCK-8 assay, transwell assay, and vascular tube formation assay were used to assess the cell viability, migration, and angiogenesis. Dual luciferase assay was performed to validate interactions between E2F1 and miR-423-5p, miR-423-5p and HIPK2.

RESULTS

HG treatment increased the cell viability, migration, and angiogenesis accompanied by upregulation of E2F1, miR-423-5p, HIF1α, and VEGF levels, but reduction in HIPK2 expression. Knockdown of E2F1 or miR-423-5p suppressed the HG-induced increases in cell viability, migration, and angiogenesis. E2F1 transcriptionally activated miR-423-5p expression and miR-423-5p mimics blocked the effects of E2F1 knockdown on angiogenesis. Moreover, miR-423-5p directly targeted HIPK2 to disinhibit HIF1α/VEGF signaling. Knockdown of HIPK2 reversed the effects of miR-423-5p inhibitor on cell viability, migration, and angiogenesis. Knockdown of E2F1 suppressed neovascularization during DR in vivo.

CONCLUSIONS

E2F1 activates miR-423-5p transcription during DR to promote angiogenesis via suppressing HIPK2 expression to disinhibit HIF1α/VEGF signaling. Strategies targeting E2F1/miR-423-5p/HIPK2 axis could be potentially used for DR treatment.

RNF144A-AS1 promotes the development of glioma cells by targeting miR-665/HMGA1 axis

PURPOSE

Glioma is a malignant tumor in the central nervous system. Long non-coding RNA (lncRNA) RNF144A-AS1 exerts a regulatory effect in cancers, but its role in glioma remains obscure and needs to be further study.

METHODS

Expressions of RNF144A-AS1, miR-665 and High-mobility group A1 (HMGA1) in glioma tissues and/or cells were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The relationship between miR-665 and RNF144A-AS1/HMGA1 was determined by bioinformatics and Dual-Luciferase Reporter assay. The effect of RNF144A-AS1 on the biological functions of glioma cells was confirmed by loss and gain experiments (including cell counting kit 8, clone formation, wound healing, Transwell, qRT-PCR and western blot). The regulatory mechanism of RNF144A-AS1/miR-665/HMGA1 axis on glioma was confirmed by rescue experiments.

RESULTS

RNF144A-AS1 and HMGA1 were high-expressed in gliomas, and miR-665 was low-expressed in gliomas, which led to the increase of glioma cell viability, proliferation, migration and invasion ability and insufficient apoptosis ability. Overexpression of RNF144A-AS1 suppressed the expressions of Bax and cleaved caspase-3, and promoted Bcl-2 expression. RNF144A-AS1 up-regulated the expression of HMGA1 by targeting miR-665, thereby promoting the development of glioma cells.

CONCLUSION

RNF144A-AS1/miR-665/HMGA1 axis implicated in the development of glioma.

A Set of 17 microRNAs Common for Brain and Cerebrospinal Fluid Differentiates Primary Central Nervous System Lymphoma from Non-Malignant Brain Tumors

The diagnosis of primary central nervous system (CNS) lymphoma, which is predominantly of the diffuse large B-cell lymphoma type (CNS DLBCL), is challenging. MicroRNAs (miRs) are gene expression-regulating non-coding RNAs that are potential biomarkers. We aimed to distinguish miR expression patterns differentiating CNS DLBCL and non-malignant CNS diseases with tumor presentation (n-ML). Next generation sequencing-based miR profiling of cerebrospinal fluids (CSFs) and brain tumors was performed. Sample source-specific (CSF vs. brain tumor) miR patterns were revealed. Even so, a set of 17 miRs differentiating CNS DLBCL from n-ML, no matter if assessed in CSF or in a tumor, was identified. Along with the results of pathway analyses, this suggests their pathogenic role in CNS DLBCL. A combination of just four of those miRs (miR-16-5p, miR-21-5p, miR-92a-3p, and miR-423-5p), assessed in CSFs, discriminated CNS DLBCL from n-ML samples with 100% specificity and 67.0% sensitivity. Analyses of paired CSF-tumor samples from patients with CNS DLBCL showed significantly lower CSF levels of miR-26a, and higher CSF levels of miR-15a-5p, miR-15b-5p, miR-19a-3p, miR-106b-3p, miR-221-3p, and miR-423-5p. Noteworthy, the same miRs belonged to the abovementioned set differentiating CNS DLBCL from non-malignant CNS diseases. Our results not only add to the basic knowledge, but also hold significant translational potential.

miR-9-5p Mediates ABCC1 to Elevate the Sensitivity of Glioma Cells to Temozolomide

Chemotherapy combined with surgery is an important clinical treatment for glioma, but endogenous or acquired temozolomide (TMZ) resistance can lead to poor prognosis. microRNA (miR)-9-5p acts in biological function of glioma, but the drug resistance of miR-9-5p in glioma is under exploration. The study intended to test the molecular mechanism of miR-9-5p in glioma cells. MTT assay was applied to investigate the chemosensitivity enhancement of miR-9-5p on TMZ in glioma cells U87-TMZ and U251-TMZ, and in vivo experiments confirmed its role on tumor growth in nude mice. The results of double luciferase reporter gene assay, qRT-PCR and WB indicated that miR-9-5p directly targeted ABCC1 (ATP binding cassette subfamily C member 1) to reduce its expressions. MTT and flow cytometry indicated that elevation of miR-9-5p or down-regulation of ABCC1 could inhibit proliferation-induced apoptosis of drug-resistant cells, and the decrease of miR-9-5p could reverse the reduction of ABCC1 on proliferation-induced apoptosis of drug-resistant cells. In vivo experiments showed that miR-9-5p could promote the anti-tumor role of TMZ. To sum up, the increase of miR-9-5p directly targets ABCC1 and may make glioma cells sensitive to TMZ.

Engineered exosomes for co-delivery of PGM5-AS1 and oxaliplatin to reverse drug resistance in colon cancer

Oxaliplatin resistance inevitably occurs in almost all cases of metastatic colorectal cancer (CRC), and it is important to study the roles of lncRNAs and their specific regulatory mechanisms in oxaliplatin resistance. Exosomes are increasingly designed for drug or functional nucleic acid delivery due to their properties, thereby improving the effectiveness of cancer therapy. The results of this study show that the low expression of PGM5 antisense RNA 1 (PGM5-AS1) in colon cancer is induced by transcription inhibitor, GFI1B. PGM5-AS1 prevents proliferation, migration, and acquired oxaliplatin tolerance of colon cancer cells. Exosomes encapsulating oxaliplatin and PGM5-AS1 can reverse drug resistance. For identifying differentially expressed target genes regarding PGM5-AS1, RNA transcriptome sequencing was performed. The mechanism by which PGM5-AS1 regulates its target genes was explored by performing experiments such as fluorescent in situ hybridization assay, dual-luciferase reporter gene assay, and RNA immunoprecipitation. The results show that by recruiting SRSF3, PGM5-AS1 activates alternate splicing to downregulate PAEP expression. For hsa-miR-423-5p, PGM5-AS1 can also act as a sponge to upregulate the NME1 expression.

Roles of the tumor suppressor inhibitor of growth family member 4 (ING4) in cancer

Inhibitor of growth family member 4 (ING4) is best known as a tumor suppressor that is frequently downregulated, deleted, or mutated in many cancers. ING4 regulates a broad array of tumor-related processes including proliferation, apoptosis, migration, autophagy, invasion, angiogenesis, DNA repair and chromatin remodeling. ING4 alters local chromatin structure by functioning as an epigenetic reader of H3K4 trimethylation histone marks (H3K4Me3) and regulating gene transcription through directing histone acetyltransferase (HAT) and histone deacetylase (HDAC) protein complexes. ING4 may serve as a useful prognostic biomarker for many cancer types and help guide treatment decisions. This review provides an overview of ING4's central functions in gene expression and summarizes current literature on the role of ING4 in cancer and its possible use in therapy.

Role of Exosomal Non-coding RNAs in Gastric Cancer: Biological Functions and Potential Clinical Applications

Gastric cancer (GC) is one of the most common fatal cancers worldwide. The communication between GC and other cells in the GC microenvironment directly affects GC progression. Recently, exosomes have been revealed as new players in intercellular communication. They play an important role in human health and diseases, including cancer, owing to their ability to carry various bioactive molecules, including non-coding RNAs (ncRNAs). NcRNAs, including micro RNAs, long non-coding RNAs, and circular RNAs, play a significant role in various pathophysiological processes, especially cancer. Increasing evidence has shown that exosomal ncRNAs are involved in the regulation of tumor proliferation, invasion, metastasis, angiogenesis, immune regulation, and treatment resistance in GC. In addition, exosomal ncRNAs have promising potential as diagnostic and prognostic markers for GC. Considering the biocompatibility of exosomes, they can also be used as biological carriers for targeted therapy. This review summarizes the current research progress on exosomal ncRNAs in gastric cancer, focusing on their biological role in GC and their potential as new biomarkers for GC and therapeutics. Our review provides insight into the mechanisms involved in GC progression, which may provide a new point cut for the discovery of new diagnostic markers and therapeutic strategies.

The Acidic Brain-Glycolytic Switch in the Microenvironment of Malignant Glioma

Malignant glioma represents a fatal disease with a poor prognosis and development of resistance mechanisms against conventional therapeutic approaches. The distinct tumor zones of this heterogeneous neoplasm develop their own microenvironment, in which subpopulations of cancer cells communicate. Adaptation to hypoxia in the center of the expanding tumor mass leads to the glycolytic and angiogenic switch, accompanied by upregulation of different glycolytic enzymes, transporters, and other metabolites. These processes render the tumor microenvironment more acidic, remodel the extracellular matrix, and create energy gradients for the metabolic communication between different cancer cells in distinct tumor zones. Escape mechanisms from hypoxia-induced cell death and energy deprivation are the result. The functional consequences are more aggressive and malignant behavior with enhanced proliferation and survival, migration and invasiveness, and the induction of angiogenesis. In this review, we go from the biochemical principles of aerobic and anaerobic glycolysis over the glycolytic switch, regulated by the key transcription factor hypoxia-inducible factor (HIF)-1α, to other important metabolic players like the monocarboxylate transporters (MCTs)1 and 4. We discuss the metabolic symbiosis model via lactate shuttling in the acidic tumor microenvironment and highlight the functional consequences of the glycolytic switch on glioma malignancy. Furthermore, we illustrate regulation by micro ribonucleic acids (miRNAs) and the connection between isocitrate dehydrogenase (IDH) mutation status and glycolytic metabolism. Finally, we give an outlook about the diagnostic and therapeutic implications of the glycolytic switch and the relation to tumor immunity in malignant glioma.

Circulating miRNAs Act as Diagnostic Biomarkers for Bladder Cancer in Urine

MicroRNAs (miRNAs) can be secreted into body fluids and have thus been reported as a new type of cancer biomarker. This study aimed to determine whether urinary miRNAs act as noninvasive biomarkers for diagnosing bladder cancer. Small RNA profiles from urine were generated for 10 patients with bladder cancer and 10 healthy controls by using next-generation sequencing. We identified 50 urinary miRNAs that were differentially expressed in bladder cancer compared with controls, comprising 44 upregulated and six downregulated miRNAs. Pathway enrichment analysis revealed that the biological role of these differentially expressed miRNAs might be involved in cancer-associated signaling pathways. Further analysis of the public database revealed that let-7b-5p, miR-149-5p, miR-146a-5p, miR-193a-5p, and miR-423-5p were significantly increased in bladder cancer compared with corresponding adjacent normal tissues. Furthermore, high miR-149-5p and miR-193a-5p expression was significantly correlated with poor overall survival in patients with bladder cancer. The qRT-PCR approach revealed that the expression levels of let-7b-5p, miR-149-5p, miR-146a-5p and miR-423-5p were significantly increased in the urine of patients with bladder cancer compared with those of controls. Although our results indicated that urinary miRNAs are promising biomarkers for diagnosing bladder cancer, this must be validated in larger cohorts in the future.

Cross-platform genomic identification and clinical validation of breast cancer diagnostic biomarkers

Introduction: Circulating non-coding RNA is an ideal source to discover novel biomarkers for non-invasive screening. However, studies for the discovery of universal miRNAs in serum and exosomes for breast cancer early diagnosis are limited.

Methods: Based on bioinformatic analysis, in vitro and in vivo studies were performed to understand the role of identified hsa-miR-423-5p in cancer proliferation, migration, cancer stem cell properties. Next, global non-coding RNA expression profiles in blood serum and exosome were performed. hsa-miR-423-5p expression from a total of 356 peripheral blood samples was evaluated and the association of hsa-miR-423-5p expression with clinical characteristics, sensitivity and specificity for breast cancer diagnosis were assessed.

Results: The expression of serum and exosomal hsa-miR-423-5p is abnormally increased in breast cancer. Suppression of hsa-miR-423-5p inhibited cell proliferation and invasion in both T47D and MDA-MB-231 breast cancer cell lines, and tumor growth in vivo. Compared with 113 healthy women, quantification analysis of hsa-miR-423-5p in 224 breast cancer samples confirmed the abnormal expression. Serum hsa-miR-423-5p was significantly associated with the clinical stage (P=0.001) and Ki-67 level (P=0.004).

Conclusions: A translational bioinformatics analysis procedure and validation by in vitro, in vivo, and clinical samples reveal that hsa-miR-423-5p could be used as a non-invasive breast cancer biomarker.

Silencing of UCA1 Protects Against MPP+-Induced Cytotoxicity in SK-N-SH Cells via Modulating KCTD20 Expression by Sponging miR-423-5p

Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder. Long noncoding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) has been implicated in PD development. Nevertheless, little insight has been gained on the mechanisms of UCA1 in PD pathogenesis. The levels of UCA1, miR-423-5p and potassium channel tetramerization domain containing 20 (KCTD20) were assessed by qRT-PCR and western blot. Cell viability was gauged by the CCK-8 assay, and cell apoptosis was detected by flow cytometry. Targeted relationships among UCA1, miR-423-5p and KCTD20 were verified by dual-luciferase reporter and RNA immunoprecipitation assays. Our data showed that MPP⁺ induced UCA1 expression in SK-N-SH cells. UCA1 silencing protected against MPP⁺-evoked cytotoxicity in SK-N-SH cells. UCA1 functioned as a miR-423-5p sponge, and the protective impact of UCA1 silencing on MPP⁺-evoked cytotoxicity was mediated by miR-423-5p. KCTD20 was a direct target of miR-423-5p, and miR-423-5p overexpression mitigated MPP⁺-triggered cell injury by down-regulating KCTD20. Furthermore, UCA1 regulated KCTD20 expression by acting as a sponge of miR-423-5p in SK-N-SH cells. Our study first identified that the silencing of UCA1 protected SK-N-SH cells from MPP⁺-evoked cytotoxicity at least in part by targeting the miR-423-5p/KCTD20 axis.

Functional mechanism and clinical implications of MicroRNA-423 in human cancers

MicroRNAs play a vital role in the regulatory mechanisms of tumorigenesis. Current research indicates that microRNA-423 (miR-423) is abnormally expressed in various human tumors and participates in multiple signaling pathways of cancer progression. In most studies, miR-423 was confirmed as oncomiR, while a few contradictory reports considered miR-423 as an anticancer miRNA. The paradoxical role in cancer may hinder the application of miR-423 as a diagnostic and therapeutic target. Simultaneously, the interaction mechanism between miR-423 and lncRNA also needs attention. In this review, we have summarized the dual role of aberrant miR-423 expression and its mechanisms in tumorigenesis, and the therapeutic potential of miR-423 in human tumors.

Cancer-associated fibroblast-secreted exosomal miR-423-5p promotes chemotherapy resistance in prostate cancer by targeting GREM2 through the TGF-β signaling pathway

Therapeutic failure in prostate cancer (PC) is believed to result from its unusually invasive and metastatic nature. Cancer-associated fibroblasts (CAFs) are essential in the tumor microenvironment. We intended to study the role of CAF-derived exosomes in the context of PC and the potential regulatory mechanism associated with miR-423-5p and GREM2. CAF-derived exosomes decreased the chemosensitivity of parental PC cells and enhanced the drug resistance of drug-resistant cells. PC-associated fibroblast-derived exosomes carrying miR-423-5p increased the resistance of PC to taxane by inhibiting GREM2 through the TGF-β pathway. Inhibition of the TGF-β pathway partially reversed the increased drug resistance in PC cells induced by CAF-derived exosomes. Inhibition of miR-423-5p enhanced the drug sensitivity of PC cells in vivo. We showed that CAF-secreted exosomal miR-423-5p promoted chemotherapy resistance in PC by targeting GREM2 through the TGF-β pathway. This study may allow the development of novel approaches for PC.

Methylation associated miR-1246 contributes to poor prognosis in gliomas treated with temozolomide

OBJECTIVE

Glioblastoma (GBM) is the most aggressive type of glioma. In this study, we aimed to investigate the biological functions and the possible mechanisms of miR-1246 in glioma.

METHODS

A miRNA-seq array was conducted in both the tumor tissues and the glioma cell lines treated with 5-Aza to determine the methylation statues of miRNAs. Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to verify the miR-1246 expressions. We used overall survival (OS) and the progress-free survival (PFS) to investigate the clinical significance of miR-1246 in the prognosis of glioma patients. Additionally, bioinformatic analysis was used for discovering the potential targets of miR-1246. Cell viability, wound-healing assay and protein expression tests were conducted after the transfection or knockdown of miR-1246 and CCNG2, respectively.

RESULTS

We found the reduced expression of miR-1246 in IDH1^MUT tumor tissues and the increased expression in the glioma cell lines treated with 5-Aza. Therefore, miR-1246 was selected as a candidate for further analysis. Kaplan-Meier analysis showed that the glioma patients with the high level of miR-1246 had the worst survival rate compared to the low level counterparts. Overexpression of miR-1246 promoted cell proliferation, migration and invasion in glioma cells. Moreover, the results showed that the downregulation of miR-1246 decreased chemoresistance by targeting CCNG2. In addition, Gene ontology (GO) analysis revealed that miR-1246 was associated with the regulations of transcription, cell cycle, cell proliferation, cell adhesion and apoptosis.

CONCLUSION

These results indicated that the miR-1246/CCNG2 axis might be a potential target for improving the drug resistance in glioma.

Hsa_circ_0084927 Regulates Cervical Cancer Advancement via Regulation of the miR-634/TPD52 Axis

Background

Cervical cancer (CC) is a common gynecological tumor that affects women’s health. Circular RNA hsa_circ_0084927 (hsa_circ_0084927) has been reported to be upregulated in CC. However, the role and regulatory mechanism of hsa_circ_0084927 in CC are unclear.

Methods

Expression of hsa_circ_0084927, microRNA (miR)-634, and tumor protein D52 (TPD52) mRNA in CC tissues and cells was examined by quantitative real-time polymerase chain reaction (qRT-PCR). The proliferation, colony formation, cell cycle progression, apoptosis, migration, and invasion of CC cells were determined with cell counting kit-8 (CCK-8), plate clone, flow cytometry, or transwell assays. The levels of cyclin D1, cleaved-caspase-3 (c-caspase 3), matrix metalloproteinase (MMP)-2, MMP-9, and TPD52 protein were evaluated with Western blotting. The targeting relationship between hsa_circ_0084927 or TPD52 and miR-634 was verified via dual-luciferase reporter and/or RNA immunoprecipitation (RIP) assays. Xenograft assay was conducted to confirm the role of hsa_circ_0084927 in vivo.

Results

Hsa_circ_0084927 and TPD52 were upregulated while miR-634 was downregulated in CC tissues and cells. Hsa_circ_0084927 silencing reduced tumor growth in vivo and induced cell cycle arrest, apoptosis, and curbed proliferation, colony formation, migration, and invasion of CC cells in vitro. Hsa_circ_0084927 regulated TPD52 expression through sponging miR-634. MiR-634 inhibitor reversed hsa_circ_0084927 knockdown-mediated impact on the malignancy of CC cells. TPD52 elevation abolished the repressive influence of miR-634 mimics on the malignancy of CC cells.

Conclusion

Hsa_circ_0084927 accelerated CC advancement via upregulating TPD52 via sponging miR-634, offering a new evidence to support hsa_circ_0084927 as a promising target for CC treatment.

miRNA signature in glioblastoma: Potential biomarkers and therapeutic targets

MicroRNAs (miRNAs) are transcripts with sizes of about 22 nucleotides, which are produced through a multistep process in the nucleus and cytoplasm. These transcripts modulate the expression of their target genes through binding with certain target regions, particularly 3' suntranslated regions. They are involved in the pathogenesis of several kinds of cancers, such as glioblastoma. Several miRNAs, including miR-10b, miR-21, miR-17-92-cluster, and miR-93, have been up-regulated in glioblastoma cell lines and clinical samples. On the other hand, expression of miR-7, miR-29b, miR-32, miR-34, miR-181 family members, and a number of other miRNAs have been decreased in this type of cancer. In the current review, we explain the role of miRNAs in the pathogenesis of glioblastoma through providing a summary of studies that reported dysregulation of these epigenetic effectors in this kind of brain cancer.

Emerging role of miRNAs as liquid biopsy markers for prediction of glioblastoma multiforme prognosis

Serum miRNAs (miRs) have gained consideration as encouraging molecular markers for cancer diagnosis and prediction of prognosis. The authors aimed to identify the exact role of miR-17-5p, miR-125b, and miR-221 among glioblastoma multiforme (GBM) patients before and after standard treatment, and correlate their expression with survival pattern. The study included 25 GBM patients and 20 healthy controls. Serum miR-17-5p, miR-125b, and miR-221 expression were analyzed before and after treatment using quantitative real-time polymerase chain reaction (qPCR). The diagnostic efficacy for the tested miRs was evaluated using the receiver operating characteristic (ROC) curve, and the relation of miRs expression versus clinical criteria for GBM was assessed. Patients' survival patterns were examined versus miRs expression levels. A significant difference was reported between miRs expression among the enrolled individuals. Both miR-17-5p and miR-221 reported significant elevations in GBM patients who: are above 60 years old, underwent biopsy resection, have a non-frontal lesion, with tumor size above 5 cm, and with performance status equals 2 according to the Eastern Cooperative Oncology Group (ECOG) Performance Status. With regard to miR-125b, a significant difference was detected according to surgery strategy, primary lesion of the tumor, and ECOG status. MiRs levels were significantly decreased for GBM patients after treatment. Survival patterns demonstrated an increase in miR-17-5p, miR-125b, and miR-221 in GBM patients with worse progression-free survival and among those with worse overall survival. Detection of serum miR-17-5p, miR-125b, and miR-221 aids in the prediction of prognosis and response to treatment strategy for GBM patients.

LEF1-AS1 accelerates tumorigenesis in glioma by sponging miR-489-3p to enhance HIGD1A

Long non-coding (lncRNA) lymphoid enhancer-binding factor 1 antisense RNA 1 (LEF1-AS1) has been validated to be implicated in manifold cancers, whereas its function in glioma has not been understood thoroughly. Hence, in this study, we tested that LEF1-AS1 expression was significantly upregulated in glioma tissues and cell lines. Besides, knockdown of LEF1-AS1 repressed cell proliferation while activated apoptosis in glioma cells in vitro, and also suppressed tumor growth in vivo. RNA pull-down and luciferase reporter assays affirmed that LEF1-AS1 could bind with miR-489-3p. In addition, miR-489-3p expression was downregulated in glioma cells. Moreover, miR-489-3p depletion partly offset LEF1-AS1 knockdown-mediated function on proliferation and apoptosis. Further, HIGD1A identified as the target gene of miR-489-3p was upregulated in glioma cells. HIGD1A silence could restrict the process of glioma. In rescue assays, upregulation of HIGD1A remedied the inhibitory impacts of LEF1-AS1 silence on glioma cell growth. In summary, our studies corroborated the regulatory mechanism of LEF1-AS1/miR-489-3p/HIGD1A axis in glioma, suggesting that targeting LEF1-AS1 might be a promising method for glioma therapy in the future.

Molecular and Cellular Complexity of Glioma. Focus on Tumour Microenvironment and the Use of Molecular and Imaging Biomarkers to Overcome Treatment Resistance

This review highlights the importance and the complexity of tumour biology and microenvironment in the progression and therapy resistance of glioma. Specific gene mutations, the possible functions of several non-coding microRNAs and the intra-tumour and inter-tumour heterogeneity of cell types contribute to limit the efficacy of the actual therapeutic options. In this scenario, identification of molecular biomarkers of response and the use of multimodal in vivo imaging and in particular the Positron Emission Tomography (PET) based molecular approach, can help identifying glioma features and the modifications occurring during therapy at a regional level. Indeed, a better understanding of tumor heterogeneity and the development of diagnostic procedures can favor the identification of a cluster of patients for personalized medicine in order to improve the survival and their quality of life.

LINC01426 contributes to clear cell renal cell carcinoma progression by modulating CTBP1/miR-423-5p/FOXM1 axis via interacting with IGF2BP1

Increasing evidence suggests that long noncoding RNAs (lncRNAs) are pivotal regulators in oncogenesis. However, the role of numerous lncRNAs has never been unmasked in clear cell renal cell carcinoma (ccRCC). Presently, we investigated the function of long intergenic nonprotein coding RNA 1426 (LINC01426) in ccRCC, as The Cancer Genome Atlas data indicated that LINC01426 was highly expressed in ccRCC tissues and its overexpression was correlated with disappointing prognosis. First, we verified that LINC01426 was indeed upregulated in ccRCC cell lines and its depletion restrained ccRCC cell proliferation and migration. Besides, we proved that LINC01426 facilitated ccRCC tumorigenesis via forkhead box M1 (FOXM1). Moreover, it was revealed that miR-423-5p was downregulated and directly targeted FOXM1 in ccRCC, and that LINC01426 positively regulated FOXM1 via its inhibition on miR-423-5p. Notably, we also uncovered that miR-423-5p was transcriptionally silenced by CTBP1 and HDAC2. Of importance, LINC01426 was certified to distribute both in the cytoplasm and the nucleus of ccRCC cells, and it increased CTBP1 expression through recruiting insulin like growth factor 2 mRNA binding protein 1 (IGF2BP1) in cytoplasm whereas interacted with CTBP1 protein to improve the transcriptional repression on miR-423-5p in nucleus. Jointly, our observations unveiled that LINC01426 aggravates ccRCC progression via IGF2BP1/CTBP1/HDAC2/miR-423-5p/FOXM1 axis, highlighting LINC01426 as a novel promising target for ccRCC treatment.

miR-423 Promotes Breast Cancer Invasion by Activating NF-κB Signaling

Objective

Breast cancer has become the most common malignancy among women worldwide; therefore, novel diagnostic and prognostic markers and therapeutic targets are urgently required. NF-κB signaling plays a pivotal role in enhancing breast cancer malignant phenotypes, especially cancer invasion and metastasis, which is the main cause of death in cancer patients. TNIP2, an important inhibitor of the NF-κB pathway, is known to involve a negative feedback loop of the NF-κB signaling cascade and to regulate tumor aggressiveness in various cancer types. However, the mRNA level of TNIP2 is barely altered in breast cancer; thus, the mechanism that regulates TNIP2 in breast cancer still needs to be elucidated.

Methods

We analyzed the expression and prognosis of miR-423 in a TCGA BRCA miRNA cohort and in clinical specimens. We detected the invasive capacity through a Matrigel-coated Transwell penetration assay, a three-dimensional (3D) spheroid invasion assay and a wound healing assay. Then, we applied luciferase assays, real-time PCR assays and Western blotting to further study the mechanism.

Results

In this study, analysis of the TCGA BRCA miRNA cohort and clinical specimens demonstrated that miR-423 was upregulated in human breast cancers and was positively correlated with clinical stage, poor overall survival and metastasis classification. Moreover, the invasiveness of breast cancer cells was enhanced by ectopic expression of miR-423 and inhibited by miR-423 downregulation. Mechanistically, upregulation of miR-423 led to activation of the NF-κB signaling pathway and elevated expression of snail and twist, while repression of miR-423 inhibited this pathway. Furthermore, the results indicated that TNIP2 is a target gene of miR-423, and suppression of TNIP2 resulted in increased invasiveness in miR-423-silenced cells.

Conclusion

Our results suggest that miR-423 is a crucial factor that enhances breast cancer cell invasion through the NF-κB signaling pathway and shed light on miR-423 as a promising prognostic and therapeutic marker for metastatic breast cancer.

LncRNA MIR155HG Promotes Temozolomide Resistance by Activating the Wnt/β-Catenin Pathway Via Binding to PTBP1 in Glioma

Temozolomide (TMZ) is widely used for glioma therapy in the clinic. Currently, the development of TMZ resistance has largely led to poor prognosis. However, very little is understood about the role of MIR155HG, as a long noncoding RNA, in TMZ resistance. In our study, MIR155HG level was markedly higher in glioma patients than in normal controls and that poor survival was positively correlated with MIR155HG expression. It was apparent that TMZ sensitivity was promoted by downregulation of MIR155HG, and this could be reversed by MIR155HG overexpression in vivo and in vitro. Furthermore, polypyrimidine tract binding protein 1 (PTBP1) was proven to bind with MIR155HG and to regulate MIR155HG-related TMZ resistance. Mechanistic investigation showed that the expression levels of both MIR155HG and PTBP1 influenced the expression of relevant proteins in the Wnt/β-catenin pathway. Collectively, the study demonstrated that the knockdown of MIR155HG increased glioma sensitivity to TMZ by inhibiting Wnt/β-catenin pathway activation via potently downregulating PTBP1.

Abuhamad A, Syahir A. Understanding Glioblastoma Biomarkers: Knocking a Mountain with a Hammer

Gliomas are the most frequent and deadly form of human primary brain tumors. Among them, the most common and aggressive type is the high-grade glioblastoma multiforme (GBM), which rapidly grows and renders patients a very poor prognosis. Meanwhile, cancer stem cells (CSCs) have been determined in gliomas and play vital roles in driving tumor growth due to their competency in self-renewal and proliferation. Studies of gliomas have recognized CSCs via specific markers. This review comprehensively examines the current knowledge of the most significant CSCs markers in gliomas in general and in glioblastoma in particular and specifically focuses on their outlook and importance in gliomas CSCs research. We suggest that CSCs should be the superior therapeutic approach by directly targeting the markers. In addition, we highlight the association of these markers with each other in relation to their cascading pathways, and interactions with functional miRNAs, providing the role of the networks axes in glioblastoma signaling pathways.

Long non‑coding RNA FLVCR1‑AS1 promotes glioma cell proliferation and invasion by negatively regulating miR‑30b‑3p

Glioblastoma (GBM) is the most common and malignant primary brain tumor in adults that originates from glial cells. The prognosis of patients with high‑grade glioma is poor. It is therefore crucial to develop effective therapeutic strategies. Long non‑coding RNAs (lncRNAs) have been reported as potential inducers or suppressors of tumor progression. Previous studies have indicated that the lncRNA Feline Leukemia Virus Subgroup C Cellular Receptor 1 Antisense RNA 1 (FLVCR1‑AS1) is involved in the development and progression of gastric and lung cancer, as well as hepatocellular carcinoma and cholangiocarcinoma; however, the biological effect of FLVCR1‑AS1 in glioma is not completely understood. The aim of the present study was to investigate how FLVCR1‑AS1 modulates cell proliferation and invasion in glioma. FLVCR1‑AS1 expression was significantly upregulated in GBM tissues compared with adjacent normal brain samples, and was higher in GBM cell lines compared with normal human astrocyte cells. Furthermore, the microRNA (miR)‑30b‑3p was revealed to be a putative target of FLVCR1‑AS1, and the suppressive effects of miR‑30b‑3p on cellular proliferation and invasion were reversed following FLVCR1‑AS1‑knockdown. The results from Cell Counting Kit‑8 and Transwell assays confirmed that FLVCR1‑AS1‑knockdown inhibited GBM cell proliferation and invasion ability. In addition, FLVCR1‑AS1 was found to directly interact with miR‑30b‑3p, and a rescue experiment further established that FLVCR1‑AS1 contributed to glioma progression by inhibiting miR‑30b‑3p. The results from the present study demonstrated that FLVCR1‑AS1 may serve an oncogenic role in GBM and promote disease progression by interacting with miR‑30b‑3p. These findings suggested that FLVCR1‑AS1 may be considered as a novel therapeutic target and diagnostic biomarker for GBM.

Upregulation of miR-340 Inhibits Tumor Growth and Mesenchymal Transition via Targeting c-MET in Glioblastoma

Background

Epithelial-mesenchymal Transition (EMT) is involved in various cancers including glioblastoma. Our previous study has shown that miR-340 negatively correlated with EMT process in glioblastoma.

Purpose

In the present study, we aim to explore the underlying molecular mechanisms of miR-340 in EMT process of glioblastomas.

Materials and Methods

Using RT-qPCR assay, we analyzed the expression of miR-340 in glioma cell lines and normal human glia (NHA) cell line. Using CCK8, Colony formation assays, transwell and Western blot assays, we investigated tumor growth and EMT process. Using luciferase reporter assay, we confirmed a target of miR-340.

Results

Our results showed that miR-340 was down-regulated in glioma cell lines (U87, U251 and LN229) compared to NHA cells. MiR-340 overexpression remarkably inhibited cell proliferation and invasion as well as up-regulated E-cadherin expression and down-regulated N-cadherin, Vimentin, ZEB1, Slug and Snail expressions in U251 and LN229 cells. Further studies have confirmed c-MET as a target gene of miR-340. The EMT-inhibitory effect of miR-340 was lost after c-MET expression was restored. We also identified the antitumorigenic activity of miR-340 in vivo.

Conclusion

These results demonstrated that miR-340 functioned as a tumor suppressor via targeting EMT process and could be a potential therapeutic candidate for treating glioblastomas.

Loss of SNHG4 Attenuated Spinal Nerve Ligation-Triggered Neuropathic Pain through Sponging miR-423-5p

Neuropathic pain is an intractable comorbidity of spinal cord injury. Increasing noncoding RNAs have been implicated in neuropathic pain development. lncRNAs have been recognized as significant regulators of neuropathic pain. lncRNA Small Nucleolar RNA Host Gene 4 (SNHG4) is associated with several tumors. However, the molecular mechanisms of SNHG4 in neuropathic pain remain barely documented. Here, we evaluated the function of SNHG4 in spinal nerve ligation (SNL) rat models. We observed that SNHG4 was significantly upregulated in SNL rat. Knockdown of SNHG4 was able to attenuate neuropathic pain progression via regulating behaviors of neuropathic pain including mechanical and thermal hyperalgesia. Moreover, knockdown of SNHG4 could repress the neuroinflammation via inhibiting IL-6, IL-12, and TNF-α while inducing IL-10 levels. Additionally, miR-423-5p was predicted as the target of SNHG4 by employing bioinformatics analysis. miR-423-5p has been reported to exert significantly poorer in several diseases. However, the role of miR-423-5p in the development of neuropathic pain is needed to be clarified. Here, in our investigation, RIP assay confirmed the correlation between miR-423-5p and SNHG4. Meanwhile, we found that miR-423-5p was significantly decreased in SNL rat models. SNHG4 regulated miR-423-5p expression negatively. As exhibited, the loss of miR-423-5p contributed to neuropathic pain progression, which was rescued by the silence of SNHG4. Therefore, our study indicated SNHG4 as a novel therapeutic target for neuropathic pain via sponging miR-423-5p.

MicroRNAs expressed in neuronal differentiation and their associated pathways: Systematic review and bioinformatics analysis

MicroRNAs (miRNAs) plays an important role in the human brain from the embryonic period to adulthood. In this sense, they influence the development of neural stem cells (NSCs), regulating cellular differentiation and survival. Therefore, due to the importance of better comprehending the regulation of miRNAs in NSCs differentiation and the lack of studies that show the panorama of miRNAs and their signaling pathways studied until now we aimed to systematically review the literature to identify which miRNAs are currently being associated with neuronal differentiation and using bioinformatics analysis to identify their related pathways. A search was carried out in the following databases: Scientific Electronic Library Online (Scielo), National Library of Medicine National Institutes of Health (PubMed), Scopus, Web of Science and Science Direct, using the descriptors "(microRNA [MeSH])" and "(neurogenesis [MeSH])". From the articles found, two independent and previously calibrated reviewers, using the EndNote X7 (Thomson Reuters, New York, NY, US), selected those that concern miRNA in the development of NSCs, based on in vitro studies. After, bioinformatic analysis was performed using the software DIANA Tools, mirPath v.3. Subsequently, data was tabulated, analyzed and interpreted. Among the 106 miRNAs cited by included studies, 55 were up-regulated and 47 were down-regulated. The bioinformatics analysis revealed that among the up-regulated miRNAs there were 24 total and 6 union pathways, and 3 presented a statistically significant difference (p ≤ 0.05). Among the down-regulated miRNAs, 46 total and 13 union pathways were found, with 7 presenting a significant difference (p ≤ 0.05). The miR-125a-5p, miR-423-5p, miR-320 were the most frequently found miRNAs in the pathways determined by bioinformatics. In this study a panel of altered miRNAs in neuronal differentiation was created with their related pathways, which could be a step towards understanding the complex network of miRNAs in neuronal differentiation.