MicroRNA-370 suppresses the progression and proliferation of human astrocytoma and glioblastoma by negatively regulating β-catenin and causing activation of FOXO3a

PKM2 promotes glioma progression by mediating CTNNB1 expression

BACKGROUND

Glioma is a common intracranial tumor, exhibiting a high degree of aggressiveness and invasiveness. Pyruvate kinase M2 (PKM2) is overexpressed in glioma tissues. However, the biological role of PKM2 in glioma is unclear.

METHODS

The qRT-PCR, CCK-8, Transwell, flow cytometry detection, western blot assays, ELISA assay, and pyruvate kinase activity assays were performed in glioma cells transfected with PKM2 shRNA to explore the function of PKM2 in glioma progression. Then, STRING website was used to predict the proteins that interacted with PKM2, and Co-IP assay was conducted to further validate their interaction. Subsequently, the above experiments were performed again to find the effect of catenin beta 1 (CTNNB1) overexpression on PKM2-deficient glioma cells. The transplanted tumor models were also established to further validate our findings.

RESULTS

PKM2 was up-regulated in glioma cells and tissues. After inhibiting PKM2, the proliferation, migration, glycolysis, and EMT of glioma cells were significantly decreased, and the proportion of apoptosis was increased. The prediction results of STRING website showed that CTNNB1 and PKM2 had the highest interaction score. The correlation between CTNNB1 and PKM2 was further confirmed by Co-IP test. PKM2 knockdown suppressed glioma cell proliferation, migration, glycolysis, and EMT, while CTNNB1 overexpression rescued these inhibitory effects. Correspondingly, PKM2 knockdown inhibited glioma growth in vivo.

CONCLUSION

In summary, these findings indicated that PKM2 promotes glioma progression by mediating CTNNB1 expression, providing a possible molecular marker for the clinical management of gliomas.

Forkhead box transcription factors (FOXOs and FOXM1) in glioma: from molecular mechanisms to therapeutics

Glioma is the most aggressive and malignant type of primary brain tumor, comprises the majority of central nervous system deaths, and is categorized into different subgroups according to its histological characteristics, including astrocytomas, oligodendrogliomas, glioblastoma multiforme (GBM), and mixed tumors. The forkhead box (FOX) transcription factors comprise a collection of proteins that play various roles in numerous complex molecular cascades and have been discovered to be differentially expressed in distinct glioma subtypes. FOXM1 and FOXOs have been recognized as crucial transcription factors in tumor cells, including glioma cells. Accumulating data indicates that FOXM1 acts as an oncogene in various types of cancers, and a significant part of studies has investigated its function in glioma. Although recent studies considered FOXO subgroups as tumor suppressors, there are pieces of evidence that they may have an oncogenic role. This review will discuss the subtle functions of FOXOs and FOXM1 in gliomas, dissecting their regulatory network with other proteins, microRNAs and their role in glioma progression, including stem cell differentiation and therapy resistance/sensitivity, alongside highlighting recent pharmacological progress for modulating their expression.

Paeoniflorin shows chondroprotective effects under IL-1β stress by regulating circ-PREX1/miR-140-3p/WNT5B axis

BACKGROUND

Osteoarthritis (OA) is a chronic and degenerative bone and joint disease, and paeoniflorin shows anti-arthritis role in OA. This study planned to investigate the mechanism related to chondroprotective role of paeoniflorin in OA.

METHODS

Real-time quantitative PCR and western blotting were performed to measure expression levels of circ-PREX1, microRNA (miR)-140-3p, Wingless-type MMTV integration site family, member 5B (WNT5B), B cell lymphoma (Bcl)-2, and Bcl-2 Associated X Protein (Bax). MTT assay, EdU assay, flow cytometry and enzyme-linked immunosorbent assay evaluated cell viability, proliferation, apoptosis and inflammatory response, respectively. Dual-luciferase reporter assay and RNA immunoprecipitation assay identified the relationship among circ-PREX1, miR-140-3p, and WNT5B.

RESULTS

IL-1β highly induced apoptosis rate, Bax expression and TNF-α product, accompanied with decreased cell viability, cell proliferation and IL-10 secretion, whereas these effects were partially reversed after paeoniflorin pretreatment. Expression of circ-PREX1 was upregulated and miR-140-3p was downregulated in cartilage tissues of patients with knee OA (KOA) and IL-1β-induced human chondrocytes (C28/I2). Circ-PREX1 overexpression and miR-140-3p silencing attenuated the suppressive effect of paeoniflorin in IL-1β-induced C28/I2 cells. Furthermore, miR-140-3p was negatively regulated by circ-PREX1. WNT5B was a downstream target of miR-140-3p and could be modulated by the circ-PREX1/miR-140-3p pathway in IL-1β-induced C28/I2 cells.

CONCLUSION

Paeoniflorin might protect human chondrocytes from IL-1β-induced inflammatory injury via circ-PREX1-miR-140-3p-WNT5B pathway, suggesting a potential preventative agent and a novel target for the treatment of KOA.

Non-coding RNAs and glioblastoma: Insight into their roles in metastasis

Glioma, also known as glioblastoma multiforme (GBM), is the most prevalent and most lethal primary brain tumor in adults. Gliomas are highly invasive tumors with the highest death rate among all primary brain malignancies. Metastasis occurs as the tumor cells spread from the site of origin to another site in the brain. Metastasis is a multifactorial process, which depends on alterations in metabolism, genetic mutations, and the cancer microenvironment. During recent years, the scientific study of non-coding RNAs (ncRNAs) has led to new insight into the molecular mechanisms involved in glioma. Many studies have reported that ncRNAs play major roles in many biological procedures connected with the development and progression of glioma. Long ncRNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) are all types of ncRNAs, which are commonly dysregulated in GBM. Dysregulation of ncRNAs can facilitate the invasion and metastasis of glioma. The present review highlights some ncRNAs that have been associated with metastasis in GBM. miRNAs, circRNAs, and lncRNAs are discussed in detail with respect to their relevant signaling pathways involved in metastasis.

Targeting Non-coding RNA for Glioblastoma Therapy: The Challenge of Overcomes the Blood-Brain Barrier

Glioblastoma (GBM) is the most malignant form of all primary brain tumors, and it is responsible for around 200,000 deaths each year worldwide. The standard therapy for GBM treatment includes surgical resection followed by temozolomide-based chemotherapy and/or radiotherapy. With this treatment, the median survival rate of GBM patients is only 15 months after its initial diagnosis. Therefore, novel and better treatment modalities for GBM treatment are urgently needed. Mounting evidence indicates that non-coding RNAs (ncRNAs) have critical roles as regulators of gene expression. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are among the most studied ncRNAs in health and disease. Dysregulation of ncRNAs is observed in virtually all tumor types, including GBMs. Several dysregulated miRNAs and lncRNAs have been identified in GBM cell lines and GBM tumor samples. Some of them have been proposed as diagnostic and prognostic markers, and as targets for GBM treatment. Most ncRNA-based therapies use oligonucleotide RNA molecules which are normally of short life in circulation. Nanoparticles (NPs) have been designed to increase the half-life of oligonucleotide RNAs. An additional challenge faced not only by RNA oligonucleotides but for therapies designed for brain-related conditions, is the presence of the blood-brain barrier (BBB). The BBB is the anatomical barrier that protects the brain from undesirable agents. Although some NPs have been derivatized at their surface to cross the BBB, optimal NPs to deliver oligonucleotide RNA into GBM cells in the brain are currently unavailable. In this review, we describe first the current treatments for GBM therapy. Next, we discuss the most relevant miRNAs and lncRNAs suggested as targets for GBM therapy. Then, we compare the current drug delivery systems (nanocarriers/NPs) for RNA oligonucleotide delivery, the challenges faced to send drugs through the BBB, and the strategies to overcome this barrier. Finally, we categorize the critical points where research should be the focus in order to design optimal NPs for drug delivery into the brain; and thus move the Oligonucleotide RNA-based therapies from the bench to the clinical setting.

Long non-coding RNA LPP-AS2 promotes glioma tumorigenesis via miR-7-5p/EGFR/PI3K/AKT/c-MYC feedback loop

Background

Glioblastoma is the most common primary malignant intracranial tumor with poor clinical prognosis in adults. Accumulating evidence indicates that long non-coding RNAs (lncRNAs) function as important regulators in cancer progression, including glioblastoma. Here, we identified a new lncRNA LPP antisense RNA-2 (LPP-AS2) and investigated its function and mechanism in the development of glioma.

Methods

High-throughput RNA sequencing was performed to discriminate differentially expressed lncRNAs and mRNAs between glioma tissues and normal brain tissues. Expression of LPP-AS2, epidermal growth factor receptor (EGFR) and miR-7-5p in glioma tissues and cell lines was detected by real-time quantitative PCR (RT-qPCR), and the functions of lncRNA LPP-AS2 in glioma were assessed by in vivo and in vitro assays. Insight into the underlying mechanism of competitive endogenous RNAs (ceRNAs) was obtained via bioinformatic analysis, dual luciferase reporter assays, RNA pulldown assays, RNA immunoprecipitation (RIP) and rescue experiments.

Results

The results of high-throughput RNA-seq indicated lncRNA LPP-AS2 was upregulated in glioma tissues and further confirmed by RT-qPCR. Higher LPP-AS2 expression was related to a poor prognosis in glioma patients. Based on functional studies, LPP-AS2 depletion inhibited glioma cell proliferation, invasion and promoted apoptosis in vitro and restrained tumor growth in vivo, overexpression of LPP-AS2 resulted in the opposite effects. In addition, LPP-AS2 and EGFR were observed in co-expression networks. LPP-AS2 was found to function as a ceRNA to regulate EGFR expression by sponging miR-7-5p in glioma cells. The result of chromatin immunoprecipitation (ChIP) assays validated that c-MYC binds directly to the promoter region of LPP-AS2. As a downstream protein of EGFR, c-MYC was modulated by LPP-AS2 and in turn enhanced LPP-AS2 expression. Thus, lncRNA LPP-AS2 promoted glioma tumorigenesis via a miR-7-5p/EGFR/PI3K/AKT/c-MYC feedback loop.

Conclusions

Our study elucidated that LPP-AS2 acted as an oncogene through a novel molecular pathway in glioma and might be a potential therapeutic approach for glioma diagnosis, therapy and prognosis.

Mir-370-3p Impairs Glioblastoma Stem-Like Cell Malignancy Regulating a Complex Interplay between HMGA2/HIF1A and the Oncogenic Long Non-Coding RNA (lncRNA) NEAT1

Glioblastoma (GBM) is the most aggressive and prevalent form of a human brain tumor in adults. Several data have demonstrated the implication of microRNAs (miRNAs) in tumorigenicity of GBM stem-like cells (GSCs). The regulatory functions of miRNAs in GSCs have emerged as potential therapeutic candidates for glioma treatment. The current study aimed at investigating the function of miR-370-3p in glioma progression, as aberrant expression of miR-370-3p, is involved in various human cancers, including glioma. Analyzing our collection of GBM samples and patient-derived GSC lines, we found the expression of miR-370-3p significantly downregulated compared to normal brain tissues and normal neural stem cells. Restoration of miR-370-3p expression in GSCs significantly decreased proliferation, migration, and clonogenic abilities of GSCs, in vitro, and tumor growth in vivo. Gene expression analysis performed on miR-370-3p transduced GSCs, identified several transcripts involved in Epithelial to Mesenchymal Transition (EMT), and Hypoxia signaling pathways. Among the genes downregulated by the restored expression of miR-370-3p, we found the EMT-inducer high-mobility group AT-hook 2 (HMGA2), the master transcriptional regulator of the adaptive response to hypoxia, Hypoxia-inducible factor (HIF)1A, and the long non-coding RNAs (lncRNAs) Nuclear Enriched Abundant Transcript (NEAT)1. NEAT1 acts as an oncogene in a series of human cancers including gliomas, where it is regulated by the Epidermal Growth Factor Receptor (EGFR) pathways, and contributes to tumor growth and invasion. Noteworthy, the expression levels of miR-370-3p and NEAT1 were inversely related in both GBM tumor specimens and GSCs, and a dual-luciferase reporter assay proved the direct binding between miR-370-3p and the lncRNAs NEAT1. Our results identify a critical role of miR-370-3p in the regulation of GBM development, indicating that miR-370-3p acts as a tumor-suppressor factor inhibiting glioma cell growth, migration and invasion by targeting the lncRNAs NEAT1, HMGA2, and HIF1A, thus, providing a potential candidate for GBM patient treatment.

MicroRNA-370 functions as a tumor suppressor in hepatocellular carcinoma via inhibition of the MAPK/JNK signaling pathway by targeting BEX2

Hepatocellular carcinoma (HCC) is a primary malignancy of the liver and occurs predominantly in patients with underlying chronic liver disease and cirrhosis. Accumulating studies have revealed that microRNAs (miRNAs) play a critical role in the development and progression of HCC. Through microarray-based gene expression profiling of HCC, miR-370, and BEX2 were identified in HCC. Hence, this study aimed to evaluate their abilities on the cellular processes in HCC. It was determined that BEX2 was highly expressed and miR-370 was poorly expressed in HCC cell lines and tissues. Then, the cell line presenting with the highest BEX2 expression and the lowest miR-370 expression was selected for subsequent gain- and loss-of-function experimentation. The antitumor effect of miR-370 on HCC cell proliferation, invasion, migration, and apoptosis, as well as the MAPK/JNK signaling pathway was examined. Meanwhile, the interaction among miR-370, BEX2, and MAPK/JNK signaling pathway was identified. BEX2 is verified to be a target of miR-370. Moreover, miR-370 exerted antitumor effect on HCC development through suppression of the MAPK/JNK signaling pathway by targeting BEX2. Later, it was further verified by in vivo experiment that overexpression of miR-370 inhibited tumor growth. Above results provide evidence that miR-370 could downregulate BEX2 gene and inhibit activation of MAPK/JNK signaling pathway, thus inhibiting the development of HCC. It provides a worth-trying novel therapeutic target for HCC treatment.

Increased circulating miR-370-3p regulates steroidogenic factor 1 in endometriosis

Endometriosis is a gynecologic disease common among reproductive-aged women caused by the growth of endometrial tissue outside the uterus. Altered expression of numerous genes and microRNAs has been reported in endometriosis. Steroidogenic factor 1 (SF-1), an essential transcriptional regulator of multiple genes involved in estrogen biosynthesis, is aberrantly increased and plays an important role in the pathogenesis of endometriosis. Here, we show the expression of SF-1 in endometriosis is regulated by miR-370-3p. Sera and tissue were collected from 20 women surgically diagnosed with endometriosis and 26 women without endometriosis. We found that miR-370-3p levels were decreased in the serum of patients with endometriosis while SF-1 mRNA levels were inversely upregulated in endometriotic lesions compared with respective controls. Transfection of primary endometriotic cells with miR-370-3p mimic or inhibitor resulted in the altered expression of SF-1 and SF-1 downstream target genes steroidogenic acute regulatory protein (StAR) and CYP19A1. Overexpression of miR-370-3p inhibited cell proliferation and induced apoptosis in endometriotic cells. This study reveals that miR-370-3p functions as a negative regulator of SF-1 and cell proliferation in endometriotic cells. We suggest a novel therapeutic strategy for controlling SF-1 in endometriosis.

LncRNA PVT1 Facilitates Tumorigenesis and Progression of Glioma via Regulation of MiR-128-3p/GREM1 Axis and BMP Signaling Pathway

The current research was aimed at probing into the role of long noncoding RNA (lncRNA) PVT1 in the pathogenesis of glioma and the regulatory mechanism of PVT1/miR-128-3p/GREM1 network in glioma via regulation of the bone morphogenetic protein (BMP) signaling pathway. Microarray analysis was used for preliminary screening for candidate lncRNAs and mRNAs in glioma tissues. Real-time quantitative polymerase chain reaction, Western blot, MTT assay, flow cytometry, migration and invasion assays, and xenograft tumor model were utilized to examine the influence of the lncRNA PVT1/miR-128-3p/GREM1 network on the biological functions of glioma cells. Luciferase assay and RNA-binding protein immunoprecipitation assay were used to validate the miR-128-3p-target relationships with lncRNA PVT1 or GREM1. In addition, the impact of GREM1 on BMP signaling pathway downstream proteins BMP2 and BMP4 was detected via Western blot. LncRNA PVT1 was highly expressed in human glioma tissues and significantly associated with WHO grade (I-II vs III-IV; p < 0.05). There existed a regulatory relationship between lncRNA PVT1 and miR-128-3p as well as that between miR-128-3p and GREM1. MiR-128-3p was downregulated, whereas GREM1 was upregulated in glioma tissues in comparison with para-carcinoma tissues. Overexpression of GREM1 promoted the proliferation and metastatic potential of glioma cells, whereas miR-128-3p mimics inhibited the glioma cell activity through targeting GREM1. Furthermore, lncRNA PVT1 acted as a sponge of miR-128-3p and, thus, influenced the BMP signaling pathway downstream proteins BMP2 and BMP4 through regulating GREM1. LncRNA PVT1 modulated GREM1 and BMP downstream signaling proteins through sponging miR-128-3p, thereby promoting tumorigenesis and progression of glioma.