Baicalin hydrate inhibits cancer progression in nasopharyngeal carcinoma by affecting genome instability and splicing

Abnormal changes in metabolites caused by m6A methylation modification: The leading factors that induce the formation of immunosuppressive tumor microenvironment and their promising potential for clinical application

BACKGROUND

N6-methyladenosine (m6A) RNA methylation modifications have been widely implicated in the metabolic reprogramming of various cell types within the tumor microenvironment (TME) and are essential for meeting the demands of cellular growth and maintaining tissue homeostasis, enabling cells to adapt to the specific conditions of the TME. An increasing number of research studies have focused on the role of m6A modifications in glucose, amino acid and lipid metabolism, revealing their capacity to induce aberrant changes in metabolite levels. These changes may in turn trigger oncogenic signaling pathways, leading to substantial alterations within the TME. Notably, certain metabolites, including lactate, succinate, fumarate, 2-hydroxyglutarate (2-HG), glutamate, glutamine, methionine, S-adenosylmethionine, fatty acids and cholesterol, exhibit pronounced deviations from normal levels. These deviations not only foster tumorigenesis, proliferation and angiogenesis but also give rise to an immunosuppressive TME, thereby facilitating immune evasion by the tumor.

AIM OF REVIEW

The primary objective of this review is to comprehensively discuss the regulatory role of m6A modifications in the aforementioned metabolites and their potential impact on the development of an immunosuppressive TME through metabolic alterations.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review aims to elaborate on the intricate networks governed by the m6A-metabolite-TME axis and underscores its pivotal role in tumor progression. Furthermore, we delve into the potential implications of the m6A-metabolite-TME axis for the development of novel and targeted therapeutic strategies in cancer research.

Inhibition of SUV39H1 reduces tumor angiogenesis via Notch1 in oral squamous cell carcinoma

Targeting tumor angiogenesis is an important approach in advanced tumor therapy. Here we investigated the effect of the suppressor of variegation 3-9 homolog 1 (SUV39H1) on tumor angiogenesis in oral squamous cell carcinoma (OSCC). The GEPIA database was used to analyze the expression of SUV39H1 in various cancer tissues. The expression of SUV39H1 in OSCC was detected by immunohistochemistry, and the correlation between SUV39H1 and Notch1 and microvascular density (MVD) was analyzed. The effect of SUV39H1 inhibition on OSCC was investigated in vivo by chaetocin treatment. The migration and tube formation of vascular endothelial cells by conditioned culture-medium of different treatments of oral squamous cell cells were measured. The transcriptional level of SUV39H1 is elevated in various cancer tissues. The transcription level of SUV39H1 in head and neck squamous cell carcinoma was significantly higher than that in control. Immunohistochemistry result showed increased SUV39H1 expression in OSCC, which was significantly correlated with T staging. The expression of SUV39H1 was significantly correlated with Notch1 and CD31. In vivo experiment chaetocin treatment significantly inhibit the growth of tumor, and reduce SUV39H1, Notch1, CD31 expression. The decreased expression of SUV39H1 in OSCC cells lead to the decreased expression of Notch1 and VEGF proteins, as well as the decreased migration and tube formation ability of vascular endothelial cells. Inhibition of Notch1 further enhance this effect. Our results suggest inhibition of SUV39H1 may affect angiogenesis by regulating Notch1 expression. This study provides a foundation for SUV39H1 as a potential therapeutic target for OSCC.

Regulatory effects of natural products on N6-methyladenosine modification: A novel therapeutic strategy for cancer

N6-methyladenosine (m6A) is considered to be the most common and abundant epigenetics modification in messenger RNA (mRNA) and noncoding RNA. Abnormal modification of m6A is closely related to the occurrence, development, progression, and prognosis of cancer. m6A regulators have been identified as novel targets for anticancer drugs. Natural products, a rich source of traditional anticancer drugs, have been utilized for the development of m6A-targeting drugs. Here, we review the key role of m6A modification in cancer progression and explore the prospects and structural modification mechanisms of natural products as potential drugs targeting m6A modification for cancer treatment.

N6-methyladenosine (m6A) methylation in kidney diseases: Mechanisms and therapeutic potential

The N6-methyladenosine (m6A) modification is regulated by methylases, commonly referred to as "writers," and demethylases, known as "erasers," leading to a dynamic and reversible process. Changes in m6A levels have been implicated in a wide range of cellular processes, including nuclear RNA export, mRNA metabolism, protein translation, and RNA splicing, establishing a strong correlation with various diseases. Both physiologically and pathologically, m6A methylation plays a critical role in the initiation and progression of kidney disease. The methylation of m6A may also facilitate the early diagnosis and treatment of kidney diseases, according to accumulating research. This review aims to provide a comprehensive overview of the potential role and mechanism of m6A methylation in kidney diseases, as well as its potential application in the treatment of such diseases. There will be a thorough examination of m6A methylation mechanisms, paying particular attention to the interplay between m6A writers, m6A erasers, and m6A readers. Furthermore, this paper will elucidate the interplay between various kidney diseases and m6A methylation, summarize the expression patterns of m6A in pathological kidney tissues, and discuss the potential therapeutic benefits of targeting m6A in the context of kidney diseases.

N6-methyladenosine (m6A) in cancer therapeutic resistance: Potential mechanisms and clinical implications

Cancer therapy resistance (CTR) is the development of cancer resistance to multiple therapeutic strategies, which severely affects clinical response and leads to cancer progression, recurrence, and metastasis. N6-methyladenosine (m6A) has been identified as the most common, abundant, and conserved internal transcriptional alterations of RNA modifications, regulating RNA splicing, translation, stabilization, degradation, and gene expression, and is involved in the development and progression of a variety of diseases, including cancer. Recent studies have shown that m6A modifications play a critical role in both cancer development and progression, especially in reversing CTR. Although m6A modifications have great potential in CTR, the specific molecular mechanisms are not fully elucidated. In this review, we summarize the potential molecular mechanisms of m6A modification in CTR. In addition, we update recent advances in natural products from Traditional Chinese Medicines (TCM) and small-molecule lead compounds targeting m6A modifications, and discuss the great potential and clinical implications of these inhibitors targeting m6A regulators and combinations with other therapies to improve clinical efficacy and overcome CTR.

Evaluation of Carbonic Anhydrase, Acetylcholinesterase, Butyrylcholinesterase, and α-Glycosidase Inhibition Effects and Antioxidant Activity of Baicalin Hydrate

Baicalin is the foremost prevalent flavonoid found in Scutellaria baicalensis. It also frequently occurs in many multi-herbal preparations utilized in Eastern countries. The current research has assessed and compared the antioxidant, antidiabetic, anticholinergic, and antiglaucoma properties of baicalin hydrate. Baicalin hydrate was tested for its antioxidant capacity using a variety of techniques, including N,N-dimethyl-p-phenylenediamine dihydrochloride radical (DMPD•+) scavenging activity, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical (ABTS•+) scavenging activity, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH•) scavenging activity, potassium ferric cyanide reduction ability, and cupric ions (Cu2+) reducing activities. Also, for comparative purposes, reference antioxidants, such as butylated hydroxyanisole (BHA), Trolox, α-Tocopherol, and butylated hydroxytoluene (BHT) were employed. Baicalin hydrate had an IC50 value of 13.40 μg/mL (r2: 0.9940) for DPPH radical scavenging, whereas BHA, BHT, Trolox, and α-Tocopherol had IC50 values of 10.10, 25.95, 7.059, and 11.31 μg/mL for DPPH• scavenging, respectively. These findings showed that baicalin hydrate had comparably close and similar DPPH• scavenging capability to BHA, α-tocopherol, and Trolox, but it performed better than BHT. Additionally, apart from these studies, baicalin hydrate was tested for its ability to inhibit a number of metabolic enzymes, including acetylcholinesterase (AChE), butyrylcholinesterase (BChE), carbonic anhydrase II (CA II), and α-glycosidase, which have been linked to several serious illnesses, such as Alzheimer's disease (AD), glaucoma, and diabetes, where the Ki values of baicalin hydrate toward the aforementioned enzymes were 10.01 ± 2.86, 3.50 ± 0.68, 19.25 ± 1.79, and 26.98 ± 9.91 nM, respectively.

Crosstalk between m6A modification and alternative splicing during cancer progression

Background N6-methyladenosine (m6A), the most prevalent internal mRNA modification in eukaryotes, is added by m6A methyltransferases, removed by m6A demethylases and recognised by m6A-binding proteins. This modification significantly influences carious facets of RNA metabolism and plays a pivotal role in cellular and physiological processes. Main body Pre-mRNA alternative splicing, a process that generates multiple splice isoforms from multi-exon genes, contributes significantly to the protein diversity in mammals. Moreover, the presence of crosstalk between m6A modification and alternative splicing, with m6A modifications on pre-mRNAs exerting regulatory control, has been established. The m6A modification modulates alternative splicing patterns by recruiting specific RNA-binding proteins (RBPs) that regulate alternative splicing or by directly influencing the interaction between RBPs and their target RNAs. Conversely, alternative splicing can impact the deposition or recognition of m6A modification on mRNAs. The integration of m6A modifications has expanded the scope of therapeutic strategies for cancer treatment, while alternative splicing offers novel insights into the mechanistic role of m6A methylation in cancer initiation and progression. Conclusion This review aims to highlight the biological functions of alternative splicing of m6A modification machinery and its implications in tumourigenesis. Furthermore, we discuss the clinical relevance of understanding m6A-dependent alternative splicing in tumour therapies.

The role of N6-methyladenosine modification in rodent models of neuropathic pain: from the mechanism to therapeutic potential

Neuropathic pain (NP) is a common chronic pain condition resulted from lesions or diseases of somatosensory nervous system, but the pathogenesis remains unclear. A growing body of evidence supports the relationship between pathogenesis and N6-methyladenosine (m6A) modifications of RNA. However, studies on the role of m6A modifications in NP are still at an early stage. Elucidating different etiologies is important for understanding the specific pathogenesis of NP. This article provides a comprehensive review on the role of m6A methylation modifications including methyltransferases ("writers"), demethylases ("erasers"), and m6A binding proteins ("readers") in NP models. Further analysis of the pathogenic mechanism relationship between m6A and NP provided novel theoretical and practical significance for clinical treatment of NP.

Baicalin Inhibits Airway Smooth Muscle Cells Proliferation through the RAS Signaling Pathway in Murine Asthmatic Airway Remodeling Model

Background

Studies that looked at asthma airway remodeling pathogenesis and prevention have led to the discovery of the rat sarcoma viral oncogene (RAS) signaling pathway as a key mechanism that controls airway smooth muscle cell (ASMC) proliferation. Baicalin has great anti-inflammatory, proliferation-inhibited, and respiratory disease-relieving properties. However, the inhibitory effects and mechanisms of baicalin on ASMC-mediated airway remodeling in mice are still poorly understood.

Methods

After establishing the asthmatic mice model by ovalbumin (OVA) and interfering with baicalin, airway remodeling characteristics such as airway resistance, mRNA, and protein expression levels of remodeling-related cytokines were measured by histopathological assessment, quantitative real-time polymerase chain reaction (qPCR), enzyme-linked immunosorbent assay (ELISA), and western blot. Further efforts on detailed mechanisms were used antibody arrays to compare the expression and activation of proteins involved in the RAS signaling pathway. In addition, validation experiments were performed in ASMC proliferation model and low-expression cells of the target gene by using shRNA.

Results

In OVA-induced asthmatic mice model, baicalin significantly reduced the infiltration of inflammatory cells in lung tissue, attenuated airway resistance, and decreased mRNA and protein expression levels of remodeling-related cytokines such as interleukin-13 (IL-13), vascular endothelial growth factor (VEGF), transforming growth factor-beta 1 (TGF-β1), matrix metallopeptidase 9 (MMP9), and tissue inhibitor of metalloproteinase 1 (TIMP1). The results of antibody arrays involved in RAS signaling pathway revealed that OVA and baicalin administration altered the activation of protein kinase C alpha type (PKC-α), A-rapidly accelerated fibrosarcoma (A-RAF), mitogen-activated protein kinase 2 (MEK2), extracellular regulated MAP kinase (ERK), MAPK interacting serine/threonine kinase 1 (MNK1), and ETS transcription factor 1 (ELK1). The above results were further verified in the ASMC proliferation model. A-RAF silencing (shA-RAF) could promote ASMC proliferation and downregulate p-MEK2, p-ERK, p-MNK1, and p-ELK1 expression.

Conclusion

The effects of baicalin against airway remodeling and ASMC proliferation might partially be achieved by suppressing the RAS signaling pathway. Baicalin may be a new therapeutic option for managing airway remodeling in asthma patients.

Crosstalk among m6A RNA methylation, hypoxia and metabolic reprogramming in TME: from immunosuppressive microenvironment to clinical application

The tumor microenvironment (TME), which is regulated by intrinsic oncogenic mechanisms and epigenetic modifications, has become a research hotspot in recent years. Characteristic features of TME include hypoxia, metabolic dysregulation, and immunosuppression. One of the most common RNA modifications, N6-methyladenosine (m⁶A) methylation, is widely involved in the regulation of physiological and pathological processes, including tumor development. Compelling evidence indicates that m⁶A methylation regulates transcription and protein expression through shearing, export, translation, and processing, thereby participating in the dynamic evolution of TME. Specifically, m⁶A methylation-mediated adaptation to hypoxia, metabolic dysregulation, and phenotypic shift of immune cells synergistically promote the formation of an immunosuppressive TME that supports tumor proliferation and metastasis. In this review, we have focused on the involvement of m⁶A methylation in the dynamic evolution of tumor-adaptive TME and described the detailed mechanisms linking m⁶A methylation to change in tumor cell biological functions. In view of the collective data, we advocate treating TME as a complete ecosystem in which components crosstalk with each other to synergistically achieve tumor adaptive changes. Finally, we describe the potential utility of m⁶A methylation-targeted therapies and tumor immunotherapy in clinical applications and the challenges faced, with the aim of advancing m⁶A methylation research.

The Role of m6A RNA Methylation in Cancer: Implication for Nature Products Anti-Cancer Research

N6-methyladenosine (m6A) RNA methylation is identified as the most common, abundant and reversible RNA epigenetic modification in messenger RNA (mRNA) and non-coding RNA, especially within eukaryotic messenger RNAs (mRNAs), which post-transcriptionally directs many important processes of RNA. It has also been demonstrated that m6A modification plays a pivotal role in the occurrence and development of tumors by regulating RNA splicing, localization, translation, stabilization and decay. Growing number of studies have indicated that natural products have outstanding anti-cancer effects of their unique advantages of high efficiency and minimal side effects. However, at present, there are very few research articles to study and explore the relationship between natural products and m6A RNA modification in tumorigenesis. m6A is dynamically deposited, removed, and recognized by m6A methyltransferases (METTL3/14, METTL16, WTAP, RBM15/15B, VIRMA, CBLL1, and ZC3H13, called as “writers”), demethylases (FTO and ALKBH5, called as “erasers”), and m6A-specific binding proteins (YTHDF1/2/3, YTHDC1/2, IGH2BP1/2/3, hnRNPs, eIF3, and FMR1, called as “readers”), respectively. In this review, we summarize the biological function of m6A modification, the role of m6A and the related signaling pathway in cancer, such as AKT, NF-kB, MAPK, ERK, Wnt/β-catenin, STAT, p53, Notch signaling pathway, and so on. Furthermore, we reviewed the current research on nature products in anti-tumor, and further to get a better understanding of the anti-tumor mechanism, thus provide an implication for nature products with anti-cancer research by regulating m6A modification in the future.

m6A modification: recent advances, anticancer targeted drug discovery and beyond

Abnormal N6-methyladenosine (m6A) modification is closely associated with the occurrence, development, progression and prognosis of cancer, and aberrant m6A regulators have been identified as novel anticancer drug targets. Both traditional medicine-related approaches and modern drug discovery platforms have been used in an attempt to develop m6A-targeted drugs. Here, we provide an update of the latest findings on m6A modification and the critical roles of m6A modification in cancer progression, and we summarize rational sources for the discovery of m6A-targeted anticancer agents from traditional medicines and computer-based chemosynthetic compounds. This review highlights the potential agents targeting m6A modification for cancer treatment and proposes the advantage of artificial intelligence (AI) in the discovery of m6A-targeting anticancer drugs.

Graphical abstract

Three stages of m6A-targeting anticancer drug discovery: traditional medicine-based natural products, modern chemical modification or synthesis, and artificial intelligence (AI)-assisted approaches for the future.

Baicalin suppresses the progression of Type 2 diabetes-induced liver tumor through regulating METTL3/m6A/HKDC1 axis and downstream p-JAK2/STAT1/clevaged Capase3 pathway

BACKGROUND

Epidemiological and clinical evidence suggests that diabetes increases the risk of liver cancer. Although the co-occurrence of type 2 diabetes (T2D) and liver cancer is becoming more frequent, the underlying mechanisms remain unclear. Even though baicalin, extensively used in traditional Chinese medicine (TCM), can control T2D and inhibit liver cancer separately, minimal research is available regarding its possible effect on T2D-induced liver cancer. Thus, in the present study, we aimed to investigate the role of baicalin in T2D-induced hepatocellular cancer, and for the first time, we particularly emphasized the regulation of baicalin in genes RNA m⁶A in hepatocellular cancer.

METHODS

Here, we constructed a cell culture model under a high concentration of glucose and a T2D-induced liver tumor model to evaluate the in vitro and in vivo role of baicalin in T2D-induced liver cancer progression. After confirming the suppressive effect of baicalin and the HKDC1 antibody on T2D-induced liver tumors, the epigenetic alterations (DNA 5mC and RNA m⁶A) of the baicalin-regulated HKDC1 gene were detected using MS and q-PCR. Next, the METTL3 gene-regulated m⁶A (2854 site) was investigated using SELECT PCR. Finally, the impact of the other three baicalin analogs (baicalein, wogonoside, and wogonin) on tumor inhibition was tested in vivo while verifying the related RNA m⁶A mechanism.

RESULTS

The results showed that baicalin and the HKDC1 antibody suppressed T2D-induced liver tumor progression in vitro and in vivo. Furthermore, baicalin significantly inhibited the epigenetic modification (DNA 5mC and RNA m⁶A) of HKDC1 in HepG2 tumors, mainly targeting the RNA m⁶A site (2854). The m⁶A-related gene, METTL3, regulated the RNA m⁶A site (2854) of HKDC1, which was also restricted by baicalin. Moreover, the study verified that baicalin regulated the METTL3/HKDC1/JAK2/STAT1/caspase-3 pathway in liver cancer cells when exposed to a high glucose concentration. In addition, the three baicalin analogs were proven to regulate the m⁶A (2854 site) of HKDC1 and suppress T2D-induced liver tumors.

CONCLUSIONS

The findings of this study revealed that baicalin suppressed T2D-induced liver tumor progression by regulating the METTL3/m⁶A/HKDC1 axis, which might support its potential application for preventing and treating T2D-induced liver cancer.

Role of Flavonoids as Epigenetic Modulators in Cancer Prevention and Therapy

Epigenetic regulation involves reversible changes in histones and DNA modifications that can be inherited without any changes in the DNA sequence. Dysregulation of normal epigenetic processes can lead to aberrant gene expression as observed in many diseases, notably cancer. Recent insights into the mechanisms of DNA methylation, histone modifications, and non-coding RNAs involved in altered gene expression profiles of tumor cells have caused a paradigm shift in the diagnostic and therapeutic approaches towards cancer. There has been a surge in search for compounds that could modulate the altered epigenetic landscape of tumor cells, and to exploit their therapeutic potential against cancers. Flavonoids are naturally occurring phenol compounds which are abundantly found among phytochemicals and have potentials to modulate epigenetic processes. Knowledge of the precise flavonoid-mediated epigenetic alterations is needed for the development of epigenetics drugs and combinatorial therapeutic approaches against cancers. This review is aimed to comprehensively explore the epigenetic modulations of flavonoids and their anti-tumor activities.

Effect, Mechanism, and Applications of Coding/Non-coding RNA m6A Modification in Tumor Microenvironment

The tumor microenvironment (TME), which includes immune cells, fibroblasts, and other components, is the site of tumor cell growth and metastasis and significantly impacts tumor development. Among them, N6-methyladenosine RNA modifications (m6A RNA modifications) are the most abundant internal modifications in coding and non-coding RNAs, which can significantly influence the cancer process and have potential as biomarkers and potential therapeutic targets for tumor therapy. This manuscript reviews the role of m6A RNA modifications in TME and their application in tumor therapy. To some extent, an in-depth understanding of the relationship between TME and m6A RNA modifications will provide new approaches and ideas for future cancer therapy.

RNA methylation in hematological malignancies and its interactions with other epigenetic modifications

Hematological malignancies are a class of malignant neoplasms attributed to abnormal differentiation of hematopoietic stem cells (HSCs). The systemic involvement, poor prognosis, chemotherapy resistance, and recurrence common in hematological malignancies urge researchers to look for novel treatment targets and mechanisms. In recent years, epigenetic abnormalities have been shown to play a vital role in tumorigenesis and progression in hematological malignancies. In addition to DNA methylation and histone modifications, which are most studied, RNA methylation has become increasingly significant. In this review, we elaborate recent advances in the understanding of RNA modification in the pathogenesis, diagnosis and molecular targeted therapies of hematological malignancies and discuss its intricate interactions with other epigenetic modifications, including DNA methylation, histone modifications and noncoding RNAs.

Study of Pharmaceutical Excipient PEG400 Alteration of Pharmacokinetics and Tissue Distribution of Main Flavonoids Metabolites of Baicalin

Background::

Polyethylene glycol 400 (PEG400), as a good traditional Chinese medicine solvent, diluent and solubilizer, is widely used as a main pharmaceutical excipient in traditional Chinese medicine compound preparations containing active ingredient baicalin. PEG400 could increase the solubility and release of baicalin in vivo, but it was unknown that PEG400 affected the absorption and distribution of baicalin or not.

Objective: :

At present, the effects of PEG400 on the pharmacokinetic characteristics and tissue distribution behaviors of the main flavonoid metabolites baicalin, baicalein 6-O-β-D-glucopyranoside (B6G) and baicalein after oral administration of baicalin were investigated by a rapid, efficient and sensitive ultra- high performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method. Moreover, we respectively studied the effects of PEG400 on the activities and protein expressions of two subtypes UDP-glucuronyltransferase 1 A8/A9 (UGT1A8 and UGT1A9) of UDP-glucuronosyltransferases (UGTs) in vitro and in vivo experiments to determine the partial mechanisms by which PEG400 altered the pharmacokinetics and tissue distribution behaviors of the three flavonoid metabolites.

Methods:

A rapid, efficient and sensitive ultra-high performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method and ELISA and so on.

Results:

The results showed that PEG400 significantly increased the Cmax and AUC0-t values (P < 0.05 or P < 0.01) of baicalin and B6G while baicalein could not be quantified due to its extremely low concentration (lower the LLOQ) in plasma. Baicalin, B6G and baicalein were mainly distributed in the stomach, small intestine, kidney and liver. PEG400 changed the distribution of three flavonoid metabolites in various tissues and also increased the activities and expressions of UGT1A8 and UGT1A9.

Conclusion::

In conclusion, PEG400 significantly altered the pharmacokinetic characteristics and tissue distribution behaviors of three flavonoid metabolites may partly result from PEG400 upregulated the activities and expressions of the drug biphasic metabolic enzymes UGT1A8 and UGT1A9, which provided a material basis and useful information to reveal the mechanism of action and clinical application of PEG400.

Baicalin mediated regulation of key signaling pathways in cancer

Baicalin has been widely investigated against different types of malignancies both at the cellular and molecular levels over the past few years. Due to its remarkable anti-proliferative potential in numerous cancer cell lines, it has created immense interest as a potential chemotherapeutic modality compared to other flavonoids. Thus, this review focuses on the recent accomplishments of baicalin and its limitations in cancer prevention and treatment. Further, combination studies and nanoformulations using baicalin to treat cancer along with the metabolism, bioavailability, toxicity, and pharmacokinetics have been discussed. The present review explains biological source, and anti-proliferative potential of baicalin against cancers including breast, colon, hepatic, leukemia, lung, and skin, as well as the relevant mechanism of action to modulate diverse signaling pathways including apoptosis, cell cycle, invasion, and migration, angiogenesis, and autophagy. The anticancer mechanism of baicalin in orthotropic and xenograft mice models have been deliberated. The combination studies of baicalin in novel therapies as chemotherapeutic adjuvants have also been summarized. The low bioavailability, fast metabolism, and poor solubility, and other significant factors that limit the clinical use of baicalin have been examined as a challenge. The improvement in the pharmacokinetics and pharmacodynamics of baicalin with newer approaches and the gaps are highlighted, which could establish baicalin as an effective and safe compound for cancer treatment as well as help to translate its potential from bench to bedside.

MicroRNA-424-5p inhibits the proliferation, migration, and invasion of nasopharyngeal carcinoma cells by decreasing AKT3 expression

This study examined the expression and potential mechanism of microRNA (miRNA)-424-5p in nasopharyngeal carcinoma (NPC). NPC tissues were collected from 40 patients who were enrolled in the study, and skin samples were collected from 26 healthy subjects during plastic surgery as controls. We performed various in vitro assays using miR-424-5p to examine its function in primary NPC-1 cells. Bioinformatics was employed to analyze potential target genes and signaling pathways of miR-424-5p. We found that miR-424-5p expression in NPC tissues is downregulated and negatively correlated with lymph node metastasis and clinical staging. Expression of miR-424-5p in NPC cells was also downregulated, and transfection with miR-424-5p mimics inhibited proliferation, migration, and invasion of NPC-1 cells. Bioinformatics identified the AKT3 gene as a potential target of miR-424-5p and dual luciferase assays confirmed this finding. Upregulation of AKT3 expression rescued the inhibitory effect of miR-424-5p on the proliferation, migration, and invasion. Our results suggest that miR-424-5p inhibited the proliferation, migration, and invasion of NPC cells by decreasing AKT3 expression.

The emerging molecular mechanism of m6A modulators in tumorigenesis and cancer progression

N⁶-methyladenosine (m⁶A) is the most abundant RNA modification; m⁶A modifications are installed by methyltransferases, removed by demethylases and recognized by reader proteins. M⁶A plays crucial roles in a variety of biological processes by regulating target RNA translation, splicing, nuclear export, and decay. Since the establishment of methylated RNA immunoprecipitation-sequencing methodology, over three hundred articles about m⁶A modulators, including "writers", "erasers" and "readers", have been reported in the last four years. In addition, an increasing number of molecular mechanisms underlying m⁶A RNA methylation in human cancers have been comprehensively clarified. The recently emerged molecular mechanisms of m⁶A modulators in cancer cell proliferation, cell cycle progression, migration and invasion, apoptosis, and autophagy remain to be summarized. Hence, this review specifically summarizes these recent advances in the understanding of m⁶A molecular mechanisms in tumorigenesis and cancer progression. In addition, we discuss the prospect of using an m⁶A methylation modulator as a new diagnostic biomarker and therapeutic target for human cancers.

The epigenetic regulators and metabolic changes in ferroptosis-associated cancer progression

Ferroptosis, a novel form of regulated cell death, is different from other types of cell death in morphology, genetics and biochemistry. Increasing evidence indicates that ferroptosis has significant implications on cell death linked to cardiomyopathy, tumorigenesis, and cerebral hemorrhage to name a few. Here we summarize current literature on ferroptosis, including organelle dysfunction, signaling transduction pathways, metabolic reprogramming and epigenetic regulators in cancer progression. With regard to organelles, mitochondria-induced cysteine starvation, endoplasmic reticulum-related oxidative stress, lysosome dysfunction and golgi stress-related lipid peroxidation all contribute to induction of ferroptosis. Understanding the underlying mechanism in ferroptosis could provide insight into the treatment of various intractable diseases including cancers.

Baicalin reverses radioresistance in nasopharyngeal carcinoma by downregulating autophagy

Background

Radiation resistance is the main cause of recurrence after radiotherapy, and increased autophagy after radiotherapy is related to radiotherapy resistance. This study aims to investigate the reversal effect of baicalin on radioresistance and its related mechanism.

Methods

CCK-8 and flow cytometry were used to detect the effect of proliferation and apoptosis by baicalin. Clone formation test was used to verify the effect of baicalin radiosensitization. Western blot analysis and electron microscopy were employed to observe the effect of baicalin on autophagy.

Results

Compared with the radiation therapy (RT) group, the RT combined baicalin (RT + BA) group showed a significantly low 2 Gy survival fraction of radiation therapy (P < 0.05). LC3-II protein expression in the RT group was significantly higher than which in the RT + BA group (P < 0.05). Electron microscopy showed that more autophagic vacuoles were observed in the RT group than those in the RT + BA group.

Conclusions

Overall, baicalin can reverse the radioresistance of human nasopharyngeal carcinoma CNE-2R cells by downregulating RT-enhanced autophagy.

Baicalin augments the differentiation of osteoblasts via enhancement of microRNA-217

Baicalin (BAI), a sort of flavonoid monomer, acquires from Scutellaria baicalensis Georgi, which was forcefully reported in diversified ailments due to the pleiotropic properties. But, the functions of BAI in osteoblast differentiation have not been addressed. The intentions of this study are to attest the influences of BAI in the differentiation of osteoblasts. MC3T3-E1 cells or rat primary osteoblasts were exposed to BAI, and then cell viability, ALP activity, mineralization process, and Runx2 and Ocn expression were appraised through implementing CCK-8, p-nitrophenyl phosphate (pNPP), Alizarin red staining, western blot, and RT-qPCR assays. The microRNA-217 (miR-217) expression was evaluated in MC3T3-E1 cells or rat primary osteoblasts after BAI disposition; meanwhile, the functions of miR-217 in BAI-administrated MC3T3-E1 cells were estimated after miR-217 inhibitor transfection. The impacts of BAI and miR-217 inhibition on Wnt/β-catenin and MEK/ERK pathways were probed to verify the involvements in BAI-regulated the differentiation of osteoblasts. BAI accelerated cell viability, osteoblast activity, and Runx2 and Ocn expression in MC3T3-E1 cells or rat primary osteoblasts, and the phenomena were mediated via activations of Wnt/β-catenin and MEK/ERK pathways. Elevation of miR-217 was observed in BAI-disposed MC3T3-E1 cells or rat primary osteoblasts, and miR-217 repression annulled the functions of BAI in MC3T3-E1 cell viability and differentiation. Additionally, the activations of Wnt/β-catenin and MEK/ERK pathways evoked by BAI were both restrained by repression of miR-217. These explorations uncovered that BAI augmented the differentiation of osteoblasts via activations of Wnt/β-catenin and MEK/ERK pathways by ascending miR-217 expression.

Regulation of N6-Methyladenosine in the Differentiation of Cancer Stem Cells and Their Fate

N6-methyladenosine (m6A) is one of the most common internal RNA modifications in eukaryotes. It is a dynamic and reversible process that requires an orchestrated participation of methyltransferase, demethylase, and methylated binding protein. m6A modification can affect RNA degradation, translation, and microRNA processing. m6A plays an important role in the regulation of various processes in living organisms. In addition to being involved in normal physiological processes such as sperm development, immunity, fat differentiation, cell development, and differentiation, it is also involved in tumor progression and stem cell differentiation. Curiously enough, cancer stem cells, a rare group of cells present in malignant tumors, retain the characteristics of stem cells and play an important role in the survival, proliferation, metastasis, and recurrence of cancers. Recently, studies demonstrated that m6A participates in the self-renewal and pluripotent regulation of these stem cells. However, considering that multiple targets of m6A are involved in different physiological processes, the exact role of m6A in cancer progression remains controversial. This article focuses on the mechanism of m6A and its effects on the differentiation of cancer stem cells, to provide a basis for elucidating the tumorigenesis mechanisms and exploring new potential therapeutic approaches.

Functions of N6-methyladenosine and its role in cancer

N6-methyladenosine (m6A) is methylation that occurs in the N6-position of adenosine, which is the most prevalent internal modification on eukaryotic mRNA. Accumulating evidence suggests that m6A modulates gene expression, thereby regulating cellular processes ranging from cell self-renewal, differentiation, invasion and apoptosis. M6A is installed by m6A methyltransferases, removed by m6A demethylases and recognized by reader proteins, which regulate of RNA metabolism including translation, splicing, export, degradation and microRNA processing. Alteration of m6A levels participates in cancer pathogenesis and development via regulating expression of tumor-related genes like BRD4, MYC, SOCS2 and EGFR. In this review, we elaborate on recent advances in research of m6A enzymes. We also highlight the underlying mechanism of m6A in cancer pathogenesis and progression. Finally, we review corresponding potential targets in cancer therapy.

Functions of RNA N6-methyladenosine modification in cancer progression

N6-methyladenosine (m6A) serves as a major RNA methylation modification and impacts the initiation and progression of various human cancers through diverse mechanisms. It has been reported that m6A RNA methylation is involved in different physiological and pathological processes, including stem cell differentiation and motility, immune response, cellular stress, tissue renewal and viral infection. In this review, the m6A modification and its regulatory functions in a few major cancers is introduced. The detection approaches for the m6A sites identification are discussed. Additionally, the potential of the RNA m6A modification in clinical application is discussed.

Functions of RNA N6-methyladenosine modification in cancer progression

N6-methyladenosine (m6A) serves as a major RNA methylation modification and impacts the initiation and progression of various human cancers through diverse mechanisms. It has been reported that m6A RNA methylation is involved in different physiological and pathological processes, including stem cell differentiation and motility, immune response, cellular stress, tissue renewal and viral infection. In this review, the m6A modification and its regulatory functions in a few major cancers is introduced. The detection approaches for the m6A sites identification are discussed. Additionally, the potential of the RNA m6A modification in clinical application is discussed.