Ginsenoside 20(s)-Rh2 as potent natural histone deacetylase inhibitors suppressing the growth of human leukemia cells

Traditional Chinese medicine for acute myelocytic leukemia therapy: exploiting epigenetic targets

Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy with historically high mortality rates. The treatment strategies for AML is still internationally based on anthracyclines and cytarabine, which remained unchanged for decades. With the rapid advance on sequencing technology, molecular targets of leukemogenesis and disease progression related to epigenetics are constantly being discovered, which are important for the prognosis and treatment of AML. Traditional Chinese medicine (TCM) is characterized by novel pharmacological mechanisms, low toxicity and limited side effects. Several biologically active ingredients of TCM are effective against AML. This review focuses on bioactive compounds in TCM targeting epigenetic mechanisms to address the complexities and heterogeneity of AML.

20(S)-ginsenoside Rh2 ameliorates ATRA resistance in APL by modulating lactylation-driven METTL3

Background

20(S)-ginsenoside Rh2(GRh2), an effective natural histone deacetylase inhibitor, can inhibit acute myeloid leukemia (AML) cell proliferation. Lactate regulated histone lactylation, which has different temporal dynamics from acetylation. However, whether the high level of lactylation modification that we first detected in acute promyelocytic leukemia (APL) is associated with all-trans retinoic acid (ATRA) resistance has not been reported. Furthermore, Whether GRh2 can regulate lactylation modification in ATRA-resistant APL remains unknown.

Methods

Lactylation and METTL3 expression levels in ATRA-sensitive and ATRA-resistant APL cells were detected by Western blot analysis, qRT-PCR and CO-IP. Flow cytometry (FCM) and APL xenograft mouse models were used to determine the effect of METTL3 and GRh2 on ATRA-resistance.

Results

Histone lactylation and METTL3 expression levels were considerably upregulated in ATRA-resistant APL cells. METTL3 was regulated by histone lactylation and direct lactylation modification. Overexpression of METTL3 promoted ATRA-resistance. GRh2 ameliorated ATRA-resistance by downregulated lactylation level and directly inhibiting METTL3.

Conclusions

This study suggests that lactylation-modified METTL3 could provide a promising strategy for ameliorating ATRA-resistance in APL, and GRh2 could act as a potential lactylation-modified METTL3 inhibitor to ameliorate ATRA-resistance in APL.

Anti-leukemia effects of ginsenoside monomer: A narrative review of pharmacodynamics study

Background

Leukemia is a prevalent disease with high mortality and morbidity rates. Current therapeutic approaches are expensive and have side effects.

Objective

In this investigation, we reviewed studies that investigated the anticancer effects of ginsenoside derivatives against leukemia and also explained the three main Ginsenoside derivatives (ginsenoside Rg3, Rh2, and Rg1) separately.

Methods

An extensive search was conducted in Pubmed, Web of Science, and Google Scholar and relevant studies that investigated anticancer effects of ginsenoside derivatives against leukemia cancer were extracted and reviewed.

Results

Preclinical studies reported that ginsenoside derivatives can induce apoptosis, suppress the proliferation of cancer cells, and induce differentiation and cell cycle arrest in leukemia cells. in addition, it can suppress the chemokine activity and extramedullary infiltration of leukemia cells from bone marrow. using herbal medicine and its derivatives is a promising approach to current health problems.

Conclusion

This review shows that ginsenoside derivatives can potentially suppress the growth of leukemia cells via various pathways and can be applied as a new natural medicine for future clinical research.

Regulation of Acetylation States by Nutrients in the Inhibition of Vascular Inflammation and Atherosclerosis

Atherosclerosis (AS) is a chronic metabolic disorder and primary cause of cardiovascular diseases, resulting in substantial morbidity and mortality worldwide. Initiated by endothelial cell stimulation, AS is characterized by arterial inflammation, lipid deposition, foam cell formation, and plaque development. Nutrients such as carotenoids, polyphenols, and vitamins can prevent the atherosclerotic process by modulating inflammation and metabolic disorders through the regulation of gene acetylation states mediated with histone deacetylases (HDACs). Nutrients can regulate AS-related epigenetic states via sirtuins (SIRTs) activation, specifically SIRT1 and SIRT3. Nutrient-driven alterations in the redox state and gene modulation in AS progression are linked to their protein deacetylating, anti-inflammatory, and antioxidant properties. Nutrients can also inhibit advanced oxidation protein product formation, reducing arterial intima-media thickness epigenetically. Nonetheless, knowledge gaps remain when it comes to understanding effective AS prevention through epigenetic regulation by nutrients. This work reviews and confirms the underlying mechanisms by which nutrients prevent arterial inflammation and AS, focusing on the epigenetic pathways that modify histones and non-histone proteins by regulating redox and acetylation states through HDACs such as SIRTs. These findings may serve as a foundation for developing potential therapeutic agents to prevent AS and cardiovascular diseases by employing nutrients based on epigenetic regulation.

Potential of Synthetic and Natural Compounds as Novel Histone Deacetylase Inhibitors for the Treatment of Hematological Malignancies

Histone deacetylases (HDACs) and histone acetyltransferases (HATs) are enzymes that remove or add acetyl groups to lysine residues of histones, respectively. Histone deacetylation causes DNA to more snugly encircle histones and decreases gene expression, whereas acetylation has the opposite effect. Through these small alterations in chemical structure, HATs and HDACs regulate DNA expression. Recent research indicates histone deacetylase inhibitors (HDACis) may be used to treat malignancies, including leukemia, B-cell lymphoma, virus-associated tumors, and multiple myeloma. These data suggest that HDACis may boost the production of immune-related molecules, resulting in the growth of CD8-positive T-cells and the recognition of nonreactive tumor cells by the immune system, thereby diminishing tumor immunity. The argument for employing epigenetic drugs in the treatment of acute myeloid leukemia (AML) patients is supported by evidence that both epigenetic changes and mutations in the epigenetic machinery contribute to AML etiology. Although hypomethylating drugs have been licensed for use in AML, additional epigenetic inhibitors, such as HDACis, are now being tested in humans. Preclinical studies evaluating the efficacy of HDACis against AML have shown the ability of specific agents, such as anobinostat, vorinostat, and tricostatin A, to induce growth arrest, apoptosis, autophagy and cell death. However, these inhibitors do not seem to be successful as monotherapies, but instead achieve results when used in conjunction with other medications. In this article, we discuss the mounting evidence that HDACis promote extensive histone acetylation, as well as substantial increases in reactive oxygen species and DNA damage in hematological malignant cells. We also evaluate the potential of various natural product-based HDACis as therapeutic agents to combat hematological malignancies.

Inhibitory Effects of Ginsenoside Compound K on Lipopolysaccharide-Stimulated Inflammatory Responses in Macrophages by Regulating Sirtuin 1 and Histone Deacetylase 4

Inflammation, an innate immune response mediated by macrophages, has been a hallmark leading to the pathophysiology of diseases. In this study, we examined the inhibitory effects of ginsenoside compound K (CK) on lipopolysaccharide (LPS)-induced inflammation and metabolic alteration in RAW 264.7 macrophages by regulating sirtuin 1 (SIRT1) and histone deacetylase 4 (HDAC4). LPS suppressed SIRT1 while promoting HDAC4 expression, accompanied by increases in cellular reactive oxygen species accumulation and pro-inflammatory gene expression; however, the addition of CK elicited the opposite effects. CK ameliorated the LPS-induced increase in glycolytic genes and abrogated the LPS-altered genes engaged in the NAD+ salvage pathway. LPS decreased basal, maximal, and non-mitochondrial respiration, reducing ATP production and proton leak in macrophages, which were abolished by CK. SIRT1 inhibition augmented Hdac4 expression along with increased LPS-induced inflammatory and glycolytic gene expression, while decreasing genes that regulate mitochondrial biogenesis; however, its activation resulted in the opposite effects. Inhibition of HDAC4 enhanced Sirt1 expression and attenuated the LPS-induced inflammatory gene expression. In conclusion, CK exerted anti-inflammatory and antioxidant properties with the potential to counteract the alterations of energy metabolism, including glycolysis and mitochondrial respiration, through activating SIRT1 and repressing HDAC4 in LPS-stimulated macrophages.

The ways for ginsenoside Rh2 to fight against cancer: the molecular evidences in vitro and in vivo

Cancer is a global public health issue that becomes the second primary cause of death globally. Considering the side effects of radio- or chemo-therapy, natural phytochemicals are promising alternatives for therapeutic interventions to alleviate the side effects and complications. Ginsenoside Rh2 (GRh2) is the main phytochemical extracted from Panax ginseng C.A. Meyer with anticancer activity. GRh2 could induce apoptosis and autophagy of cancer cells and inhibit proliferation, metastasis, invasion, and angiogenesis in vitro and in vivo. In addition, GRh2 could be used as an adjuvant to chemotherapeutics to enhance the anticancer effect and reverse the adverse effects. Here we summarized the understanding of the molecular mechanisms underlying the anticancer effects of GRh2 and proposed future directions to promote the development and application of GRh2.

Potential of ginsenoside Rh2and its derivatives as anti-cancer agents

As a steroid skeleton-based saponin, ginsenoside Rh₂ (G-Rh₂) is one of the major bioactive ginsenosides from the plants of genus Panax L. Many studies have reported the notable pharmacological activities of G-Rh₂ such as anticancer, antiinflammatory, antiviral, antiallergic, antidiabetic, and anti-Alzheimer's activities. Numerous preclinical studies have demonstrated the great potential of G-Rh₂ in the treatment of a wide range of carcinomatous diseases in vitro and in vivo. G-Rh₂ is able to inhibit proliferation, induce apoptosis and cell cycle arrest, retard metastasis, promote differentiation, enhance chemotherapy and reverse multi-drug resistance against multiple tumor cells. The present review mainly summarizes the anticancer effects and related mechanisms of G-Rh₂ in various models as well as the recent advances in G-Rh₂ delivery systems and structural modification to ameliorate its anticancer activity and pharmacokinetics characteristics.

Ginsenoside Rh2 Induces HeLa Apoptosis through Upregulating Endoplasmic Reticulum Stress-Related and Downstream Apoptotic Gene Expression

Cervical cancer is a common gynecological malignancy afflicting women all over the world. Ginsenoside Rh2 (GRh2), especially 20(S)-GRh2, is a biologically active component in the natural plant ginseng, which can exhibit anticancer effects. Here, we aimed to investigate the effect of 20(S)-GRh2 on cervical cancer and elucidate the underlying mechanism through RNA-seq. In this study, the CCK-8 assay showed that 20(S)-GRh2 inhibited HeLa cell viability in a time- and dose-dependent manner. Caspase 3 activity and Annexin V staining results showed that 20(S)-GRh2 induced apoptosis of HeLa cells. Gene function enrichment analysis revealed that the biological process gene ontology (GO) terms were associated with the apoptotic signaling pathway. Biological process GO terms' similarity network indicated that apoptosis might be from endoplasmic reticulum stress (ERs). Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that 20(S)-GRh2 primarily modulates apoptosis pathway genes. Combined protein-protein interaction network, hub gene screening, and qPCR validation data showed that ERs-related genes (ATF4 and DDIT3) and the downstream apoptotic genes (JUN, FOS, BBC3, and PMAIP1) were potential novel targets of 20(S)-GRh2-inducing cervical cancer cell apoptosis. Differential transcript usage analysis indicated that DDIT3 is also a differential transcript and its usage of the isoform (ENST00000552740.5) was reduced by 20(S)-GRh2. Molecular docking suggested that 20(S)-GRh2 binds to the targets (ATF4, DDIT3, JUN, FOS, BBC3, and PMAIP1) with high affinity. In conclusion, our findings indicated that 20(S)-GRh2 might promote ERs-related apoptosis of cervical cancer cells by regulating the DDIT3-based targets' signal pathway. The role of 20(S)-GRh2 at the transcriptome level provides novel targets and evidence for the treatment of cervical cancer.

Targeting Epigenetic Regulatory Enzymes for Cancer Therapeutics: Novel Small-Molecule Epidrug Development

Dysregulation of the epigenetic enzyme-mediated transcription of oncogenes or tumor suppressor genes is closely associated with the occurrence, progression, and prognosis of tumors. Based on the reversibility of epigenetic mechanisms, small-molecule compounds that target epigenetic regulation have become promising therapeutics. These compounds target epigenetic regulatory enzymes, including DNA methylases, histone modifiers (methylation and acetylation), enzymes that specifically recognize post-translational modifications, chromatin-remodeling enzymes, and post-transcriptional regulators. Few compounds have been used in clinical trials and exhibit certain therapeutic effects. Herein, we summarize the classification and therapeutic roles of compounds that target epigenetic regulatory enzymes in cancer treatment. Finally, we highlight how the natural compounds berberine and ginsenosides can target epigenetic regulatory enzymes to treat cancer.

Regulatory effect of Panax notoginseng saponins on the oxidative stress and histone acetylation induced by porcine circovirus type 2

Porcine circovirus type 2 (PCV2) exists widely in swine populations worldwide, and healthy PCV2 virus carriers have enhanced the severity of the infection, which is becoming more difficult to control. This study investigated the regulatory effect of Panax notoginseng saponins (PNS) on the oxidative stress and histone acetylation modification induced by PCV2 in vitro and in mice. In vitro, PNS significantly increased the scavenging capacities of superoxide anion radicals (O2•-) and hydroxyl radicals (•OH) and reduced the content of hydrogen peroxide (H2O2) induced by PCV2 in porcine alveolar macrophages (3D4/2). In addition, PNS decreased the protein expression level of histone H4 acetylation (Ac-H4) by increasing the activity of histone deacetylase (HDAC) in PCV2-infected 3D4/2 cells. In vivo, PNS enhanced the scavenging capacities of •OH and O2•- and reduced the content of H2O2 in the spleens of PCV2-infected mice. PNS also reduced the protein expression level of histone H3 acetylation (Ac-H3) by reducing the activity of histone acetylase (HAT) and increasing the activity of HDAC in the spleens of PCV2-infected mice. PCV2 infection activated oxidative stress and histone acetylation in vitro and in mice, but PNS ameliorated this oxidative stress. The research can provide experimental basis for exploring the antioxidant effect and the regulation of histone acetylation of PNS on PCV2-infected 3D4/2 cells and mice in vitro and in vivo, and provide new ideas for the treatment of PCV2 infection.

Research Progress of Natural Small-Molecule Compounds Related to Tumor Differentiation

Tumor differentiation is a therapeutic strategy aimed at reactivating the endogenous differentiation program of cancer cells and inducing cancer cells to mature and differentiate into other types of cells. It has been found that a variety of natural small-molecule drugs can induce tumor cell differentiation both in vitro and in vivo. Relevant molecules involved in the differentiation process may be potential therapeutic targets for tumor cells. Compared with synthetic drugs, natural small-molecule antitumor compounds have the characteristics of wide sources, structural diversity and low toxicity. In addition, natural drugs with structural modification and transformation have relatively concentrated targets and enhanced efficacy. Therefore, using natural small-molecule compounds to induce malignant cell differentiation represents a more targeted and potential low-toxicity means of tumor treatment. In this review, we focus on natural small-molecule compounds that induce differentiation of myeloid leukemia cells, osteoblasts and other malignant cells into functional cells by regulating signaling pathways and the expression of specific genes. We provide a reference for the subsequent development of natural small molecules for antitumor applications and promote the development of differentiation therapy.

Impact of HIV-1 subtypes on gross deletion in the nef gene after Korean Red Ginseng treatment

Background

Methods

Results

Conclusion

Integrated bioinformatic analysis and experiment confirmation of the antagonistic effect and molecular mechanism of ginsenoside Rh2 in metastatic osteosarcoma

This study aimed to compare the gene expression variation of clinical primary osteosarcoma (OS) and metastatic OS, identify expression profiles and signal pathways related to disease classification, and systematically evaluate the potential anticancer effect and molecular mechanism of ginsenoside Rh2 on OS. A raw dataset (GSE14359), which excluded GSM359137 and GSM359138, was downloaded from the Gene Expression Omnibus. Differentially expressed genes (DEGs) and principal component analysis (PCA) were obtained with limma. Pathways enrichment analysis was understood by GSEA app. Rh2-associated targets were harvested and mapped through PharmMapper and Cytoscape 3.4.0. The toxicity of Rh2 was determined using crystal staining and MTT assay on 143B and MG63 cell lines. The relative protein expression was confirmed through Western blot analysis. The mitochondrial membrane potential (△Ψm) was evaluated by JC-1 fluorescence staining. The cell mobility was measured via wound healing and transwell assays. A total of 752 genes were upregulated, while 161 genes were downregulated. GSEA and PCA displayed significant function enrichment and classification. Through PharmMapper and Cytoscape 3.4.0, Rh2 was found to target the mitogen activated protein kinase (MAPK) and PI3K signaling pathways, which are the key pathways in the metastasis of OS. Furthermore, Rh2 induced a concentration-dependent decrease in cell viability and early apoptosis associated with ΔΨm decline, while a non-lethal dose of Rh2 weakened the metastatic capability. Moreover, systematic evaluation showed that promoting the MAPK signaling pathway and inhibiting PI3K/Akt/mTOR were correlated with the anticancer effects of Rh2 on metastatic OS. In conclusion, transcriptome-derived approaches may be beneficial in diagnosing early metastases, and Rh2, a multi-targeting agent, shows promising application potential in suppressing metastatic OS in an MAPK- and PI3K/Akt/mTOR-dependent manner.

Anticancer Effects of Ginsenoside Rh2: A Systematic Review

BACKGROUND

As one of the effective pharmacological constituents of Ginseng Radix et Rhizoma, ginsenoside Rh2 (Rh2) exerts a remarkable anticancer effect on various cancer cell lines in vitro and strongly inhibits tumor growth in vivo without severe toxicity.

OBJECTIVE

This article reviewed existing evidence supporting the anticancer effects of Rh2 to classify and conclude previous and current knowledge on the mechanisms and therapeutic effects of Rh2, as well as to promote the clinical application of this natural product.

CONCLUSION

This article reviewed the anticancer efficacies and mechanisms of Rh2, including the induction of cell cycle arrest and programmed cell death, repression of metastasis, alleviation of drug resistance, and regulation of the immune system. Finally, this paper discussed the research and application prospects of Rh2.

Therapeutic effects of ginsenosides on breast cancer growth and metastasis

Breast cancer is the most common cause of cancer-related deaths among women worldwide. Thus, the development of new and effective low-toxicity drugs is vital. The specific characteristics of breast cancer have allowed for the development of targeted therapy towards each breast cancer subtype. Nevertheless, increasing drug resistance is displayed by the changing phenotype and microenvironments of the tumor through mutation or dysregulation of various mechanisms. Recently, emerging data on the therapeutic potential of biocompounds isolated from ginseng have been reported. Therefore, in this review, various roles of ginsenosides in the treatment of breast cancer, including apoptosis, autophagy, metastasis, epithelial-mesenchymal transition, epigenetic changes, combination therapy, and drug delivery system, have been discussed.

Anticancer property of ginsenoside Rh2 from ginseng

Ginseng has been used as a well-known traditional Chinese medicine since ancient times. Ginsenosides as its main active constituents possess a broad scope of pharmacological properties including stimulating immune function, enhancing cardiovascular health, increasing resistance to stress, improving memory and learning, developing social functioning and mental health in normal persons, and chemotherapy. Ginsenoside Rh2 (Rh2) is one of the major bioactive ginsenosides from Panax ginseng. When applied to cancer treatment, Rh2 not only exhibits the anti-proliferation, anti-invasion, anti-metastasis, induction of cell cycle arrest, promotion of differentiation, and reversal of multi-drug resistance activities against multiple tumor cells, but also alleviates the side effects after chemotherapy or radiotherapy. In the past decades, nearly 200 studies on Rh2 in the treatment of cancer have been published, however no specific reviews have been conducted by now. So the purpose of this review is to provide a systematic summary and analysis of the anticancer effects and the potential mechanisms of Rh2 extracted from Ginseng then give a future prospects about it. In the end of this paper the metabolism and derivatives of Rh2 also have been documented.

Fermented Ginseng Extract, BST204, Suppresses Tumorigenesis and Migration of Embryonic Carcinoma through Inhibition of Cancer Stem Cell Properties

The pharmacological effects of BST204—a fermented ginseng extract—on several types of cancers have been reported. However, the effects of ginseng products or single ginsenosides against cancer stem cells are still poorly understood. In this study, we identified the anti-tumorigenic and anti-invasive activities of BST204 through the suppression of the cancer stem cell marker, CD133. The treatment of embryonic carcinoma cells with BST204 induced the expression of the tumor suppressor protein, p53, which decreased the expression of cell cycle regulatory proteins and downregulated the expression of CD133 and several stemness transcription factors. These changes resulted in both the inhibition of tumor cell proliferation and tumorigenesis. The knockdown of CD133 suggests that it has a role in tumorigenesis, but not in cancer cell proliferation or cell cycle arrest. Treatment with BST204 resulted in the reduced expression of the mesenchymal marker, N-cadherin, and the increased expression of the epithelial marker, E-cadherin, leading to the suppression of tumor cell migration and invasion. The knockdown of CD133 also exhibited an anti-invasive effect, indicating the role of CD133 in tumor invasion. The single ginsenosides Rg3 and Rh2—major components of BST204—exhibited limited effects against cancer stem cells compared to BST204, suggesting possible synergism among several ginsenoside compounds.

Diverse autophagy and apoptosis in myeloid leukemia cells induced by 20(s)-GRh2 and blue LED irradiation

Autophagy is an important mechanism for cell death regulation. To improve the anticancer effect during the treatment of leukemia and promote the apoptosis of leukemic cells, it is important to define the relationship between autophagy and apoptosis. A key bioactive compound in traditional Chinese medicine, 20(s)-Ginsenoside (GRh2), demonstrated an advancement in leukemia treatment. Blue LED therapy (BL) is a physical treatment method that can induce leukemic cell death. In this study, we tested the effect of 20(s)-GRh2, BL, and their combination (BL-GRh2) on the activation of leukemic cell apoptosis and autophagy. Both treatments, whether used individually or simultaneously, induce apoptosis through the induction of reactive oxygen species (ROS), disrupted mitochondrial membrane potential (MMP) and regulated the expression of apoptosis-related genes and proteins. Furthermore, using western blotting to analyze the autophagy markers LC3B and P62, we detected the activation of autophagy. In cells treated with autophagy inhibitor 3-MA, both autophagy and apoptosis were inhibited, either by BL alone or by BL-GRh2. However, apoptosis in 20(s)-GRh2-treated cells was enhanced. In cells treated with apoptosis suppressor Z-VAD-FMK, autophagy was inhibited in the BL and BL-GRh2-treated cells, although it was enhanced in cells treated with 20(s)-GRh2 alone. Moreover, we observed a stronger induction of apoptosis by BL-GRh2 in myeloid leukemia cells. Our data indicate that autophagy induced by different factors can play diverse roles on the same cells. Our results also indicate that the combination of traditional Chinese medicine with physical therapy may be a new strategy for anti-cancer therapy.

Antiproliferative Activity of Combined Biochanin A and Ginsenoside Rh₂ on MDA-MB-231 and MCF-7 Human Breast Cancer Cells

Breast cancer is the most frequently diagnosed cancer in women worldwide. The antiproliferative activities of biochanin A (BA) and ginsenoside Rh₂ were determined by evaluating their inhibitory effect on MDA-MB-231 human breast cancer cell proliferation. The combination of BA with Rh₂ was also assessed. In MDA cells, combination treatment led to a decrease in the EC₅₀ values of BA and Rh₂ to 25.20 μM and 22.75 μM, respectively. In MCF-7 cells, the EC₅₀ values of combined BA and Rh₂ decreased to 27.68 μM and 25.41 μM, respectively. BA combined with Rh₂ also improved the inhibition of MDA-MB-231 and MCF-7 cell migration and invasion compared to the individual compounds. Western blot analysis demonstrated upregulation in p-p53, p-p38, and p-ASK1 proteins while levels of TRAF2 were downregulated. These results suggest that BA combined with Rh₂ exhibits synergistic effects against MDA-MB-231 and MCF-7 cell proliferation.

Activation of PAR4 Upregulates p16 through Inhibition of DNMT1 and HDAC2 Expression via MAPK Signals in Esophageal Squamous Cell Carcinoma Cells

A previous study showed that a downexpression of protease-activated receptor 4 (PAR4) is associated with the development of esophageal squamous cell carcinoma (ESCC). In this study, we explored the relationship between PAR4 activation and the expression of p16, and elucidated the underlying mechanisms in PAR4 inducing the tumor suppressor role in ESCC. ESCC cell lines (EC109 and TE-1) were treated with PAR4-activating peptide (PAR4-AP). Immunohistochemistry for DNA methyltransferase 1 (DNMT1) and histone deacetylase 2 (HDAC2) was performed in 26 cases of ESCC tissues. We found that DNMT1 and HDAC2 immunoreactivities in ESCC were significantly higher than those in adjacent noncancerous tissues. PAR4 activation could suppress DNMT1 and HDAC2, as well as increase p16 expressions, whereas silencing PAR4 dramatically increased HDAC2 and DNMT1, as well as reduced p16 expressions. Importantly, the chromatin immunoprecipitation-PCR (ChIP-PCR) data indicated that treatment of ESCC cells with PAR4-AP remarkably suppressed DNMT1 and HDAC2 enrichments on the p16 promoter. Furthermore, we demonstrated that activation of PAR4 resulted in an increase of p38/ERK phosphorylation and activators for p38/ERK enhanced the effect of PAR4 activation on HDAC2, DNMT1, and p16 expressions, whereas p38/ERK inhibitors reversed these effects. Moreover, we found that activation of PAR4 in ESCC cells significantly inhibited cell proliferation and induced apoptosis. These findings suggest that PAR4 plays a potential tumor suppressor role in ESCC cells and represents a potential therapeutic target of this disease.

Fermented ginseng extract, BST204, disturbs adipogenesis of mesenchymal stem cells through inhibition of S6 kinase 1 signaling

Background

The biological and pharmacological effects of BST204, a fermented ginseng extract, have been reported in various disease conditions. However, its molecular action in metabolic disease remains poorly understood. In this study, we identified the antiadipogenic activity of BST204 resulting from its inhibition of the S6 kinase 1 (S6K1) signaling pathway.

Methods

The inhibitory effects of BST204 on S6K1 signaling were investigated by immunoblot, nuclear fractionation, immunoprecipitation analyses. The antiadipogenic effect of BST204 was evaluated by measuring mRNA levels of adipogenic genes and by chromatin immunoprecipitation and quantitative real-time polymerase chain reaction analysis.

Results

Treatment with BST204 inhibited activation and nuclear translocation of S6K1, further decreasing the interaction between S6K1 and histone H2B in 10T1/2 mesenchymal stem cells. Subsequently, phosphorylation of H2B at serine 36 (H2BS36p) by S6K1 was reduced by BST204, inducing an increase in the mRNA expression of Wnt6, Wnt10a, and Wnt10b, which disturbed adipogenic differentiation and promoted myogenic and early osteogenic gene expression. Consistently, BST204 treatment during adipogenic commitment suppressed the expression of adipogenic marker genes and lipid drop formation.

Conclusion

Our results indicate that BST204 blocks adipogenesis of mesenchymal stem cells through the inhibition of S6K1-mediated histone phosphorylation. This study suggests the potential therapeutic strategy using BST204 to combat obesity and musculoskeletal diseases.

20(S)-Ginsenoside Rh2 Induce the Apoptosis and Autophagy in U937 and K562 Cells

Acute myeloid leukemia (AML) and Chronic myelogenous leukemia (CML) are common leukemia in adults. 20(S)-GRh2 is an important bioactive substance that is present in Panax ginseng. However, there are no investigations that deal with the comparison of apoptosis, the occurrence of autophagy, and the relationship between apoptosis and autophagy after being treated with 20(S)-GRh2 in AML and CML. In this study, we explored the effect of 20(S)-GRh2 on the AML and CML (U937 and K562). Fluorescence microscopy, CCK-8, Quantitative realtime PCR, Western blot, transmission electron microscopy (TEM), and flow cytometric analysis were used to detect the occurrence of cell proliferation inhibition, apoptosis, and autophagy. By using the above methods, it was determined that apoptosis induced by 20(S)-GRh2 was more obvious in K562 than U937 cells and 20(S)-GRh2 could generate autophagy in K562 and U937 cells. When pretreated by a specific inhibitor of autophagy, (3-methyladenine), the 20(S)-GRh2-induced apoptosis was enhanced, which indicated that 20(S)-GRh2-induced autophagy may protect U937 and K562 cells from undergoing apoptotic cell death. On the other hand, pretreated by an apoptosis suppressor (Z-VAD-FMK), it greatly induced the autophagy and partially prevented 20(S)-GRh2 induced apoptosis. This phenomenon indicated that 20(S)-GRh2-induced autophagy may serve as a survival mechanism and apoptosis and autophagy could act as partners to induce cell death in a cooperative manner. These findings may provide a rationale for future clinical application by using 20(S)-GRh2 combined autophagy inhibitors for AML and CML.

Anti-cancer effects of naturally derived compounds targeting histone deacetylase 6-related pathways

Alterations of the epigenetic machinery, affecting multiple biological functions, represent a major hallmark enabling the development of tumors. Among epigenetic regulatory proteins, histone deacetylase (HDAC)6 has emerged as an interesting potential therapeutic target towards a variety of diseases including cancer. Accordingly, this isoenzyme regulates many vital cellular regulatory processes and pathways essential to physiological homeostasis, as well as tumor multistep transformation involving initiation, promotion, progression and metastasis. In this review, we will consequently discuss the critical implications of HDAC6 in distinct mechanisms relevant to physiological and cancerous conditions, as well as the anticancer properties of synthetic, natural and natural-derived compounds through the modulation of HDAC6-related pathways.

20(S)-Ginsenoside Rh2 suppresses proliferation and migration of hepatocellular carcinoma cells by targeting EZH2 to regulate CDKN2A-2B gene cluster transcription

20(S)-Ginsenoside Rh2 (20(S)-GRh2) exerts important pharmacological effects with regard to the control of human hepatocellular carcinoma (HCC). EZH2 is a potent histone methyltransferase of H3K27me³, which has been determined as an oncogene in many malignancies. The CDKN2A-2B gene cluster encodes three important tumor suppressors, P14, P15 and P16. In this study, the anticancer effect and molecular mechanism of 20(S)-GRh2 on HCC was investigated. Treatment of HCC cells with 20(S)-GRh2 inhibited cell proliferation, migration and induced cell cycle arrest at the G0/G1 phase, and inhibited tumor growth in vivo. We demonstrate for the first time that this effect was specifically mediated by down-regulating expression of EZH2. Further molecular mechanism study indicated that the decreased EZH2 promoted P14, P15 and P16 gene transcription through reducing H3K27me³ modification in the promoter of CDKN2A-2B gene cluster loci. Similarly, silencing of EZH2 by siRNA down-regulated P14, P15, P16 mRNA levels and inhibited HCC cell proliferation. Our results suggested that EZH2 could be a potentially therapeutic target by 20(S)-GRh2 in HCC, which provided a rationale for the development of drugs that inhibited histone methylase as a strategy against various cancers.

Ginsenoside 20(S)-Rh2 Induces Apoptosis and Differentiation of Acute Myeloid Leukemia Cells: Role of Orphan Nuclear Receptor Nur77

Ginsenoside 20(S)-Rh2 has been shown to induce apoptosis and differentiation of acute myeloid leukemia (AML) cells. However, the underlying molecular mechanisms are not fully understood. In our study, 20(S)-Rh2 induced the expression of orphan nuclear receptor Nur77 and death receptor proteins Fas, FasL, DR5, and TRAIL, as well as the cleavage of caspase 8 and caspase 3 in HL-60 cells. Importantly, shNur77 attenuated 20(S)-Rh2-induced apoptosis and Fas and DR5 expression. Meanwhile, 20(S)-Rh2 promoted Nur77 translocation from the nucleus to mitochondria and enhanced the interaction between Nur77 and Bcl-2, resulting in the exposure of the BH3 domain of Bcl-2 and activation of Bax. Furthermore, 20(S)-Rh2 promoted the differentiation of HL-60 cells as evidenced by Wright-Giemsa staining, NBT reduction assay, and detection of the myeloid differentiation marker CD11b by flow cytometry. Notably, shNur77 reversed 20(S)-Rh2-mediated HL-60 differentiation. Additionally, 20(S)-Rh2 also exhibited an antileukemic effect and induced Nur77 expression in NOD/SCID mice with the injection of HL-60 cells into the tail vein. Together, our studies suggest that the Nur77-mediated signaling pathway is highly involved in 20(S)-Rh2-induced apoptosis and differentiation of AML cells.

Natural Compound Histone Deacetylase Inhibitors (HDACi): Synergy with Inflammatory Signaling Pathway Modulators and Clinical Applications in Cancer

The remarkable complexity of cancer involving multiple mechanisms of action and specific organs led researchers Hanahan and Weinberg to distinguish biological capabilities acquired by cancer cells during the multistep development of human tumors to simplify its understanding. These characteristic hallmarks include the abilities to sustain proliferative signaling, evade growth suppressors, resist cell death, enable replicative immortality, induce angiogenesis, activate invasion and metastasis, avoid immune destruction, and deregulate cellular energetics. Furthermore, two important characteristics of tumor cells that facilitate the acquisition of emerging hallmarks are tumor-promoting inflammation and genome instability. To treat a multifactorial disease such as cancer, a combination treatment strategy seems to be the best approach. Here we focus on natural histone deacetylase inhibitors (HDACi), their clinical uses as well as synergies with modulators of the pro-inflammatory transcription factor signaling pathways.

Profiling of ginsenosides in the two medicinal Panax herbs based on ultra-performance liquid chromatography-electrospray ionization-mass spectrometry

As the king of herb plants, ginseng has been used for nearly 5000 years in medicines in Asia and recently in the West. Ginsenosides, the main active constituents in Panax herbs, have prominent immunoregulatory effects. Although extensively studied in the roots, ginsenosides have not been studied with regard to their profiles and natural variations in the leaf, stem, petiole, lateral root, and main roots during development or among species. In this study, a sensitive ultra-performance liquid chromatography-electrospray ionization–mass spectrometry method with a shorter chromatographic running time was developed and validated for simultaneous quantification of ten ginsenosides. Comparing ginsenoside contents in various parts during different developmental stages revealed part-specific accumulation of most ginsenosides. Further investigation indicated that Rg3 accumulated at significantly higher levels in the petiole of P. ginseng than in that of P. quinquefolius. The relative ratio of ginsenoside Rb2 to Rb1 appears to be a candidate metabolic marker for identifying the ginseng cultivar within a diverse collection of ginseng accessions. In addition, the PCA showed that aboveground parts differed significantly between species and can be considered as species-specific markers rather than roots. This comprehensive survey, providing reliable, affordable and adequate scientific evidence, could be used to differentiate two species and discriminate ginseng cultivar ages.

Saponins from Chinese Medicines as Anticancer Agents

Saponins are glycosides with triterpenoid or spirostane aglycones that demonstrate various pharmacological effects against mammalian diseases. To promote the research and development of anticancer agents from saponins, this review focuses on the anticancer properties of several typical naturally derived triterpenoid saponins (ginsenosides and saikosaponins) and steroid saponins (dioscin, polyphyllin, and timosaponin) isolated from Chinese medicines. These saponins exhibit in vitro and in vivo anticancer effects, such as anti-proliferation, anti-metastasis, anti-angiogenesis, anti-multidrug resistance, and autophagy regulation actions. In addition, related signaling pathways and target proteins involved in the anticancer effects of saponins are also summarized in this work.

Ginsenoside Rh2 inhibits proliferation and induces apoptosis in human leukemia cells via TNF-α signaling pathway

Ginsenoside Rh2, a triterpene saponin extracted from Panax ginseng, exhibits pharmacological activity against multiple cancers. However, the anticancer mechanism of ginsenoside Rh2 is unclear. In this study, we found that ginsenoside Rh2 effectively inhibits growth and induces apoptosis of HL-60 cells. Using microarray technology, we found that tumor necrosis factor-α (TNF-α) is clearly up-regulated. Furthermore, anti-TNF-α antibody relieved the Rh2-induced HL-60 cell apoptosis via suppression of caspase-8, caspase-9, and caspase-3 activation. In addition, TNF-α up-regulation was also observed in other Rh2-treated cancer cell lines. These results demonstrate that TNF-α plays a key role in ginsenoside Rh2-induced cell apoptosis.