β-Asarone Induces Apoptosis and Cell Cycle Arrest of Human Glioma U251 Cells via Suppression of HnRNP A2/B1-Mediated Pathway In Vitro and In Vivo

The Regulatory Network of hnRNPs Underlying Regulating PKM Alternative Splicing in Tumor Progression

One of the hallmarks of cancer is metabolic reprogramming in tumor cells, and aerobic glycolysis is the primary mechanism by which glucose is quickly transformed into lactate. As one of the primary rate-limiting enzymes, pyruvate kinase (PK) M is engaged in the last phase of aerobic glycolysis. Alternative splicing is a crucial mechanism for protein diversity, and it promotes PKM precursor mRNA splicing to produce PKM2 dominance, resulting in low PKM1 expression. Specific splicing isoforms are produced in various tissues or illness situations, and the post-translational modifications are linked to numerous disorders, including cancers. hnRNPs are one of the main components of the splicing factor families. However, there have been no comprehensive studies on hnRNPs regulating PKM alternative splicing. Therefore, this review focuses on the regulatory network of hnRNPs on PKM pre-mRNA alternative splicing in tumors and clinical drug research. We elucidate the role of alternative splicing in tumor progression, prognosis, and the potential mechanism of abnormal RNA splicing. We also summarize the drug targets retarding tumorous splicing events, which may be critical to improving the specificity and effectiveness of current therapeutic interventions.

Emerging Roles and Mechanisms of RNA Modifications in Neurodegenerative Diseases and Glioma

Despite a long history of research, neurodegenerative diseases and malignant brain tumor gliomas are both considered incurable, facing challenges in the development of treatments. Recent evidence suggests that RNA modifications, previously considered as static components of intracellular RNAs, are in fact dynamically regulated across various RNA species in cells and play a critical role in major biological processes in the nervous system. Innovations in next-generation sequencing have enabled the accurate detection of modifications on bases and sugars within various RNA molecules. These RNA modifications influence the stability and transportation of RNA, and crucially affect its translation. This review delves into existing knowledge on RNA modifications to offer a comprehensive inventory of these modifications across different RNA species. The detailed regulatory functions and roles of RNA modifications within the nervous system are discussed with a focus on neurodegenerative diseases and gliomas. This article presents a comprehensive overview of the fundamental mechanisms and emerging roles of RNA modifications in these diseases, which can facilitate the creation of innovative diagnostics and therapeutics for these conditions.

Role of N6-methyladenosine methylation in glioma: recent insights and future directions

Glioma is the most pervasive intracranial tumor in the central nervous system (CNS), with glioblastoma (GBM) being the most malignant type having a highly heterogeneous cancer cell population. There is a significantly high mortality rate in GBM patients. Molecular biomarkers related to GBM malignancy may have prognostic values in predicting survival outcomes and therapeutic responses, especially in patients with high-grade gliomas. In particular, N6-methyladenine (m6A) mRNA modification is the most abundant form of post-transcriptional RNA modification in mammals and is involved in regulating mRNA translation and degradation. Cumulative findings indicate that m6A methylation plays a crucial part in neurogenesis and glioma pathogenesis. In this review, we summarize recent advances regarding the functional significance of m6A modification and its regulatory factors in glioma occurrence and progression. Significant advancement of m6A methylation-associated regulators as potential therapeutic targets is also discussed.

Ethnic, Botanic, Phytochemistry and Pharmacology of the Acorus L. Genus: A Review

The genus Acorus, a perennial monocotyledonous-class herb and part of the Acoraceae family, is widely distributed in the temperate and subtropical zones of the Northern and Southern Hemispheres. Acorus is rich in biological activities and can be used to treat various diseases of the nervous system, cardiovascular system, and digestive system, including Alzheimer's disease, depression, epilepsy, hyperlipidemia, and indigestion. Recently, it has been widely used to improve eutrophic water and control heavy-metal-polluted water. Thus far, only three species of Acorus have been reported in terms of chemical components and pharmacological activities. Previously published reviews have not further distinguished or comprehensively expounded the chemical components and pharmacological activities of Acorus plants. By carrying out a literature search, we collected documents closely related to Acorus published from 1956 to 2022. We then performed a comprehensive and systematic review of the genus Acorus from different perspectives, including botanical aspects, ethnic applications, phytochemistry aspects, and pharmacological aspects. Our aim was to provide a basis for further research and the development of new concepts.

Surmounting Cancer Drug Resistance: New Perspective on RNA-Binding Proteins

RNA-binding proteins (RBPs), being pivotal elements in both physiological and pathological processes, possess the ability to directly impact RNA, thereby exerting a profound influence on cellular life. Furthermore, the dysregulation of RBPs not only induces alterations in the expression levels of genes associated with cancer but also impairs the occurrence of post-transcriptional regulatory mechanisms. Consequently, these circumstances can give rise to aberrations in cellular processes, ultimately resulting in alterations within the proteome. An aberrant proteome can disrupt the equilibrium between oncogenes and tumor suppressor genes, promoting cancer progression. Given their significant role in modulating gene expression and post-transcriptional regulation, directing therapeutic interventions towards RBPs represents a viable strategy for combating drug resistance in cancer treatment. RBPs possess significant potential as diagnostic and prognostic markers for diverse cancer types. Gaining comprehensive insights into the structure and functionality of RBPs, along with delving deeper into the molecular mechanisms underlying RBPs in tumor drug resistance, can enhance cancer treatment strategies and augment the prognostic outcomes for individuals afflicted with cancer.

Biological function and research progress of N6-methyladenosine binding protein heterogeneous nuclear ribonucleoprotein A2B1 in human cancers

N6-methyladenosine (m6A) is the most prevalent internal modification found in both mRNA and lncRNA. It exerts reversible regulation over RNA function and affects RNA processing and metabolism in various diseases, especially tumors. The m6A binding protein, hnRNPA2B1, is extensively studied as a member of the heterogeneous nuclear ribonucleoprotein (hnRNP) protein family. It is frequently dysregulated and holds significant importance in multiple types of tumors. By recognizing m6A sites for variable splicing, maintaining RNA stability, and regulating translation and transport, hnRNPA2B1 plays a vital role in various aspects of tumor development, metabolism, and regulation of the immune microenvironment. In this review, we summarized the latest research on the functional roles and underlying molecular mechanisms of hnRNPA2B1. Moreover, we discussed its potential as a target for tumor therapy.

β-asarone attenuates the proliferation, migration and enhances apoptosis of retinoblastoma through Wnt/β-catenin signaling pathway

PURPOSE

β-asarone is the prime component of essential oil extracted from Acori graminei Rhizoma, which plays an inhibitory role in various tumors. Here, we aim to investigate the functions as well as the mechanism of β-asarone in retinoblastoma (RB).

METHODS

RB cell lines SO-Rb50 and HXO-Rb44 were treated with different doses of β-asarone. Then, CCK8 and BrdU experiments were adopted to examine the RB cell proliferation. Wound healing test and Transwell assay were employed to detect cell migration and invasion. RB cell apoptosis was tested by flow cytometry and Western blot. An RB cell xenograft model was constructed on nude mice for testing the role of β-asarone on RB cell growth in vivo. RT-PCR and Western blot were used to determine the effect of β-asarone on Wnt/β-catenin signaling pathway. Furthermore, the Wnt/β-catenin pathway inhibitor PNU-74654 and activator HLY78 were administered to RB cells for confirming the effects of β-asarone in Wnt/β-catenin pathway.

RESULTS

In vivo experiment showed that β-asarone attenuated SO-Rb50 cell growth in nude mice. Further research found that β-asarone significantly repressed Wnt/β-catenin canonical pathway activation.

CONCLUSION

Prior inhibition of Wnt/β-catenin pathway abolished the antitumor effects induced by β-asarone. β-asarone exerted antitumor effects in RB cells by inactivating the Wnt/β-catenin signaling pathway.

The Expression of hnRNP A2/B1 in Benign and Malignant Lung Lesions and Its Early Diagnosis Value in NSCLC

Lung cancer in its occurrence and development of different stages exist different biological behavior changes. This paper studies the expression of heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 in benign and malignant lung lesions and its early diagnosis value of nonsmall-cell lung cancer (NSCLC), aiming to provide reference for the early diagnosis and therapy of NSCLC. Some lung surgery specimens are selected from January 2021 to March 2022. All cases received no radiotherapy and chemotherapy before surgery, including 90 sufferers with benign lung lesions as the contrast set. hnRNP A2/B1 expressions are measured for comparison. The experimental results show that for lung cancer sufferers, the positive expression of hnRNP A2/B1 in their malignant lesion tissue is notoriously higher than that in their benign lesion tissue, and hnRNP A2/B1 is differently expressed in different differentiation and in different stages.

β-Asarone suppresses TGF-β/Smad signaling to reduce the invasive properties in esophageal squamous cancer cells

Esophageal cancer is one of the most common malignancies which induces cancer-related death. Cancer metastasis and recurrence are the main obstacle faced in esophageal cancer treatment. β-Asarone has been shown to act as an anti-cancer reagent in various cancer types. However, the anti-cancer activities of β-Asarone in esophageal cancer have not been shown. In the current study, we show that β-Asarone suppressed the proliferation of esophageal squamous cancer cells (ESCC) in both dose- and time-dependent manners. Moreover, β-Asarone treatment increases activated caspase 3, caspase 9, and cleaved poly ADP-ribose polymerase, and induces apoptosis in ESCC. Additionally, β-Asarone also suppresses epithelial-mesenchymal transition (EMT) and the invasive and migratory abilities in ESCC. Interestingly, β-Asarone suppresses TGF-β/Smad signaling by inhibition of TGF-β-induced phosphorylation of Smad2 and Smad3. Importantly, we show that inhibition of TGF-β/Smad signaling activation is critical for β-Asarone-suppressed EMT. Our data revealed a novel role of β-Asarone which targets invasive properties by inhibiting TGF-β/Smad signaling activation in ESCC. Our study suggests the potential application of β-Asarone to reduce cancer metastasis and recurrence in esophageal cancer treatment.

Emerging roles of hnRNP A2B1 in cancer and inflammation

Heterogeneous nuclear ribonucleoproteins (hnRNPs) are a group of RNA-binding proteins with important roles in multiple aspects of nucleic acid metabolism, including the packaging of nascent transcripts, alternative splicing, transactivation of gene expression, and regulation of protein translation. As a core component of the hnRNP complex in mammalian cells, heterogeneous nuclear ribonucleoprotein A2B1 (hnRNP A2B1) participates in and coordinates various molecular events. Given its regulatory role in inflammation and cancer progression, hnRNP A2B1 has become a novel player in immune response, inflammation, and cancer development. Concomitant with these new roles, a surprising number of mechanisms deemed to regulate hnRNP A2B1 functions have been identified, including post-translational modifications, changes in subcellular localization, direct interactions with multiple DNAs, RNAs, and proteins or the formation of complexes with them, which have gradually made hnRNP A2B1 a molecular target for multiple drugs. In light of the rising interest in the intersection between cancer and inflammation, this review will focus on recent knowledge of the biological roles of hnRNP A2B1 in cancer, immune response, and inflammation.

Effect of hnRNPA2/B1 on the proliferation and apoptosis of glioma U251 cells via the regulation of AKT and STAT3 pathways

Glioma is the most common malignant tumor in the human central nervous system. Although heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNPA2/B1) was previously presumed to be a tumor-promoting gene, the relationship between hnRNPA2/B1 and glioma is unclear. Targeting hnRNPA2/B1 interference in glioma cells can significantly inhibit proliferation and increase apoptosis of human glioma cells in vitro. In a tumor xenograft model, knockdown of hnRNPA2/B1 suppressed tumor growth in glioma cells in vivo. In terms of a mechanism, the knockdown of hnRNPA2/B1 led to inactivation of the AKT and STAT3 signaling pathways, which ultimately reduced the expression of B-cell lymphoma-2 (Bcl-2), CyclinD1 and proliferating cell nuclear antigen (PCNA). Collectively, these data suggest that the inhibition of hnRNPA2/B1 can reduce the growth of gliomas through STAT3 and AKT signaling pathways, and this inhibition is expected to be a therapeutic target for gliomas.

A five-m6A regulatory gene signature is a prognostic biomarker in lung adenocarcinoma patients

We analyzed the prognostic value of N6-methyladenosine (m6A) regulatory genes in lung adenocarcinoma (LADC) and their association with tumor immunity and immunotherapy response. Seventeen of 20 m6A regulatory genes were differentially expressed in LDAC tissue samples from the TCGA and GEO databases. We developed a five-m6A regulatory gene prognostic signature based on univariate and Lasso Cox regression analysis. Western blot analysis confirmed that the five prognostic m6A regulatory proteins were highly expressed in LADC tissues. We constructed a nomogram with five-m6A regulatory gene prognostic risk signature and AJCC stages. ROC curves and calibration curves showed that the nomogram was well calibrated and accurately distinguished high-risk and low-risk LADC patients. Weighted gene co-expression analysis showed significant correlation between prognostic risk signature genes and the turquoise module enriched with cell cycle genes. The high-risk LADC patients showed significantly higher PD-L1 levels, increased tumor mutational burden, and a lower proportion of CD8⁺ T cells in the tumor tissues and improved response to immune checkpoint blockade therapy. These findings show that this five-m6A regulatory gene signature is a prognostic biomarker in LADC and that immune checkpoint blockade is a potential therapeutic option for high-risk LADC patients.

The HNRNPA2B1-MST1R-Akt axis contributes to epithelial-to-mesenchymal transition in head and neck cancer

The deregulation of splicing factors and alternative splicing are increasingly viewed as major contributory factors in tumorigenesis. In this study, we report overexpression of a key splicing factor, heterogeneous nuclear ribonucleoprotein A2B1 (HNRNPA2B1), and thereby misregulation of alternative splicing, which is associated with the poor prognosis of head and neck cancer (HNC). The role of HNRNPA2B1 in HNC tumorigenesis via deregulation of alternative splicing is not well understood. Here, we found that the CRISPR/Cas9-mediated knockout of HNRNPA2B1 results in inhibition of HNC cells growth via the misregulation of alternative splicing of MST1R, WWOX, and CFLAR. We investigated the mechanism of HNRNPA2B1-mediated HNC cells growth and found that HNRNPA2B1 plays an important role in the alternative splicing of a proto-oncogene, macrophage stimulating 1 receptor (MST1R), which encodes for the recepteur d'origine nantais (RON), a receptor tyrosine kinase. Our results indicate that HNRNPA2B1 mediates the exclusion of cassette exon 11 from MST1R, resulting in the generation of RON∆165 isoform, which was found to be associated with the activation of Akt/PKB signaling in HNC cells. Using the MST1R-minigene model, we validated the role of HNRNPA2B1 in the generation of RON∆165 isoform. The depletion of HNRNPA2B1 results in the inclusion of exon 11, thereby reduction of RON∆165 isoform. The decrease of RON∆165 isoform causes inhibition of Akt/PKB signaling, which results in the upregulation of E-cadherin and downregulation of vimentin leading to the reduced epithelial-to-mesenchymal transition. The overexpression of HNRNPA2B1 in HNRNPA2B1 knockout cells rescues the expression of the RON∆165 isoform and leads to activation of Akt/PKB signaling and induces epithelial-to-mesenchymal transition in HNC cells. In summary, our study identifies HNRNPA2B1 as a putative oncogene in HNC that promotes Akt/PKB signaling via upregulation of RON∆165 isoform and promotes epithelial to mesenchymal transition in head and neck cancer cells.

Knockdown of circ-TTBK2 Inhibits Glioma Progression by Regulating miR-1283 and CHD1

Background

Dysregulated circular RNAs (circRNAs) are involved in the development of glioma. This paper aims to analyze the role and mechanism of circRNA tau tubulin kinase 2 (circ-TTBK2) in glioma progression.

Methods

The glioma samples and normal brain tissues were collected. The levels of circ-TTBK2, microRNA-1283 (miR-1283) and chromodomain helicase DNA-binding protein 1 (CHD1) were examined via quantitative reverse transcription polymerase chain reaction or Western blot. Cell proliferation, migration, invasion and glycolysis were determined via 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide, transwell assay, Western blot, glucose and lactate assay kits. The target relationship was analyzed via dual-luciferase reporter assay. The xenograft model was established using U251 cells.

Results

circ-TTBK2 expression was increased in glioma tissues and cells. circ-TTBK2 knockdown suppressed glioma cell proliferation, migration, invasion and glycolysis. circ-TTBK2 was a sponge for miR-1283, and knockdown of miR-1283 reversed the effect of circ-TTBK2 silence on glioma progression. CHD1 was targeted via miR-1283, and miR-1283 repressed glioma cell proliferation, migration, invasion and glycolysis via decreasing CHD1. Knockdown of circ-TTBK2-reduced CHD1 expression by mediating miR-1283. Silence of circ-TTBK2 reduced xenograft tumor growth.

Conclusion

Down-regulation of circ-TTBK2 suppressed glioma development by regulating miR-1283 and CHD1, providing a new mechanism for understanding glioma pathogenesis.

β-Asarone Exerts Antioxidative Effects on H2O2-Stimulated PC12 Cells by Activating Nrf2/HO-1 Pathway

Oxidative stress-mediated neuron damage is considered an important contributor to the pathogenesis and development of neurodegenerative diseases. Although β-asarone is widely known for its neuroprotective pharmacological properties, the exact mechanism of β-asarone against oxidative stress has not been fully elucidated. The aim of the present study was to investigate underlying mechanisms of β-asarone against oxidative damage in PC12 cells. Our results demonstrated that the treatment of β-asarone significantly alleviated the reduction in cell viability and the excessive accumulation of lactate dehydrogenase (LDH), malondialdehyde (MDA) and reactive oxygen species (ROS) by increasing the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH). Moreover, β-asarone pretreatment also activated nuclear factor 2 erythroid-related factor 2 (Nrf2) and its downstream target heme oxygenase-1 (HO-1), which was involved in quenching reactive oxygen to inhibit oxidative stress. Furthermore, when silenced by Nrf2 siRNA, the protective effect of β-asarone was reduced and the oxidative stress induced by H2O2 was enhanced. In conclusion, our findings revealed that β-asarone could reduce oxidative stress via activating Nrf2/HO-1 pathway in PC12 cells, highlighting the potential therapeutic role of β-asarone in neurodegenerative diseases.

RNA-binding proteins in tumor progression

RNA-binding protein (RBP) has a highly dynamic spatiotemporal regulation process and important biological functions. They are critical to maintain the transcriptome through post-transcriptionally controlling the processing and transportation of RNA, including regulating RNA splicing, polyadenylation, mRNA stability, mRNA localization, and translation. Alteration of each process will affect the RNA life cycle, produce abnormal protein phenotypes, and thus lead to the occurrence and development of tumors. Here, we summarize RBPs involved in tumor progression and the underlying molecular mechanisms whereby they are regulated and exert their effects. This analysis is an important step towards the comprehensive characterization of post-transcriptional gene regulation involved in tumor progression.

Regulating the CCNB1 gene can affect cell proliferation and apoptosis in pituitary adenomas and activate epithelial-to-mesenchymal transition

The aim of the present study was to investigate the role and potential regulatory mechanisms of cyclin B1 (CCNB1) in the proliferation, apoptosis and epithelial-to-mesenchymal transition (EMT) in pituitary adenomas. A total of 24 specimens were included in the present study. The expression levels of CCNB1 protein in two normal pituitary and 22 pituitary adenoma tissues were determined by western blotting. CCNB1 was knocked-down by lentiviral-mediated infection of short hairpin RNA (shRNA) in GH3 and MMQ cell lines. The proliferation, cell cycle and apoptosis of GH3 and MMQ cell lines were detected using a Cell Counting Kit-8 and flow cytometer. Reverse transcription-quantitative PCR was utilized to detect the expression level of CCNB1 gene and EMT markers. In the present study, resveratrol (RES) was used as an inhibitor of CCNB1. The protein expression level of CCNB1 in pituitary adenomas was higher than that in normal pituitary tissue, as assessed by western blot analysis. In addition, the expression level of CCNB1 in invasive pituitary adenomas was higher when comparing invasive pituitary adenomas and non-invasive pituitary adenomas. Knockdown of CCNB1 resulted in significant decreases in cell viability and proliferation, arrested cell cycle at the G₂/M phase and increased apoptosis. In addition, knockdown of CCNB1 significantly decreased the expression levels of the mesothelial cell marker N-cadherin (P<0.001), but significantly increased the expression levels of the epithelial cell markers E-cadherin (P<0.01) and p120-catenin (P<0.001). Further analyses identified that RES inhibited the expression level of CCNB1, and RES treatment exhibited a similar effect as CCNB1 shRNA infection. The present study suggested that suppressing the expression level of CCNB1 could regulate the proliferation and apoptosis of pituitary tumor cells and alter the expression level of various EMT markers. In addition, RES treatment could be used as an inhibitor of CCNB1. The present study also identified the molecular mechanisms underlying CCNB1 role in EMT.

Experimental evidence for use of Acorus calamus (asarone) for cancer chemoprevention

Cancer is one of the major non-communicable diseases posing substantial challenges in both developing and developed countries. The options available for treatment of different cancer are associated with various limitations, including severe toxicity, drug resistance, poor outcomes and a high risk of relapse. Hence, an increased attention and necessity for screening of various phytochemicals from natural sources for superior and safer alternative has been ongoing for several decades. In recent years, phytochemicals like galantamine, erwinaze, rivastigmine, resveratrol from natural sources have been found to be important therapeutic targets for the treatment of various diseases including cancer, neurodegeneration, diabetes, and cardiovascular effects. Acorus calamus (Sweet flag), and/or its bioactive phytochemical alpha (α)-and beta (β)-asarone, is a well-known drug in the traditional system of medicine which possesses anti-tumor and chemo-preventive activities as evident from numerous pre-clinical studies both in-vitro and in-vivo. In this article, we critically review the current available scientific evidences of A. calamus and/or asarone for cancer chemoprevention based on preclinical in-vitro and in-vivo models. In addition, we also have compiled and discussed the molecular targets of mechanism(s) involved in the anti-cancer activity of A. calamus/asarone. Still, extensive in-vivo studies are necessary using various animal models to understand the molecular mechanism behind the pharmacological activity of the bioactive phytochemicals derived from A. calamus. It is strongly believed that the comprehensive evidence presented in this article could deliver a possible source for researchers to conduct future studies pertaining to A. calamus and/or its bioactive phytochemicals asarone for cancer chemoprevention.