Interplay of DNA methyltransferase 1 and EZH2 through inactivation of Stat3 contributes to β-elemene-inhibited growth of nasopharyngeal carcinoma cells

Beta-elemene: A phytochemical with promise as a drug candidate for tumor therapy and adjuvant tumor therapy

BACKGROUND

β-Elemene (IUPAC name: (1 S,2 S,4 R)-1-ethenyl-1-methyl-2,4-bis(prop-1-en-2-yl) cyclohexane), is a natural compound found in turmeric root. Studies have demonstrated its diverse biological functions, including its anti-tumor properties, which have been extensively investigated. However, these have not yet been reviewed. The aim of this review was to provide a comprehensive summary of β-elemene research, with respect to disease treatment.

METHODS

β-Elemene-related articles were found in PubMed, ScienceDirect, and Google Scholar databases to systematically summarize its structure, pharmacokinetics, metabolism, and pharmacological activity. We also searched the Traditional Chinese Medicine System Pharmacology database for therapeutic targets of β-elemene. We further combined these targets with the relevant literature for KEGG and GO analyses.

RESULTS

Studies on the molecular mechanisms underlying β-elemene activity indicate that it regulates multiple pathways, including STAT3, MAPKs, Cyclin-dependent kinase 1/cyclin B, Notch, PI3K/AKT, reactive oxygen species, METTL3, PTEN, p53, FAK, MMP, TGF-β/Smad signaling. Through these molecular pathways, β-elemene has been implicated in tumor cell proliferation, apoptosis, migration, and invasion and improving the immune microenvironment. Additionally, β-elemene increases chemotherapeutic drug sensitivity and reverses resistance by inhibiting DNA damage repair and regulating pathways including CTR1, pak1, ERK1/2, ABC transporter protein, Prx-1 and ERCC-1. Nonetheless, owing to its lipophilicity and low bioavailability, additional structural modifications could improve the efficacy of this drug.

CONCLUSION

β-Elemene exhibits low toxicity with good safety, inhibiting various tumor types via diverse mechanisms in vivo and in vitro. When combined with chemotherapeutic drugs, it enhances efficacy, reduces toxicity, and improves tumor killing. Thus, β-elemene has vast potential for research and development.

Elemene Antitumor Drugs Development Based on "Molecular Compatibility Theory" and Clinical Application: A Retrospective and Prospective Outlook

Elemene, derived from Curcuma wenyujin, one of the "8 famous genuine medicinal materials of Zhejiang province," exhibits remarkable antitumor activity. It has gained wide recognition in clinical practice for effectiveness on tumors. Dr. XIE Tian, introduced the innovative concept of "molecular compatibility theory" by combining Chinese medicine principles, specifically the "monarch, minister, assistant, and envoy" theory, with modern biomedical technology. This groundbreaking approach, along with a systematic analysis of Chinese medicine and modern biomedical knowledge, led to the development of elemene nanoliposome formulations. These novel formulations offer numerous advantages, including low toxicity, well-defined composition, synergistic effects on multiple targets, and excellent biocompatibility. Following the principles of the "molecular compatibility theory", further exploration of cancer treatment strategies and methods based on elemene was undertaken. This comprehensive review consolidates the current understanding of elemene's potential antitumor mechanisms, recent clinical investigations, advancements in drug delivery systems, and structural modifications. The ultimate goal of this review is to establish a solid theoretical foundation for researchers, empowering them to develop more effective antitumor drugs based on the principles of "molecular compatibility theory".

FBP1 induced by β-elemene enhances the sensitivity of gefitinib in lung cancer

BACKGROUND

β-elemene is known to play a critical role in tumorigenesis as well as tyrosine kinase inhibitor (TKI) resistance in lung cancer. However, the biological function and molecular mechanism remain largely unknown.

METHODS

In this study, the common genes involved in gefitinib resistance and β-elemene were identified using bioinformatic analysis. The expression of FBP1 was examined by qRT-PCR and Western blot analysis. Cell proliferation, flow cytometry, clone formation and IC50 assays were performed to assess the effects of β-elemene and FBP1. Western blot analysis was used to evaluate apoptosis-related gene expression. Finally, in vivo experiments were conducted to assess the crucial role of FBP1 in gefitinib-resistant HCC827/GR cells in nude mice.

RESULTS

Screening analysis demonstrated that fructose-1,6-bisphosphatase (FBP1) was induced by β-elemene and downregulated in gefitinib-resistant lung cells. Functionally, overexpression of FBP1 inhibited proliferation and gefitinib resistance and promoted apoptosis of PC9/GR and HCC827/GR cells in vitro. Mechanistically, FBP1 impeded the nuclear translocation of p-STAT3. The FBP1/STAT3 axis was required for FBP1-mediated apoptosis-related gene expression. In vivo experiments further confirmed the enhanced effects of FBP1 on lung cancer cell sensitivity to gefitinib.

CONCLUSION

Our research indicated that β-elemene suppressed proliferation and enhanced sensitivity to gefitinib by inducing apoptosis through the FBP1/STAT3 axis in gefitinib-resistant lung cancer cells.

β-Elemene alleviates cisplatin resistance in oral squamous cell carcinoma cell via inhibiting JAK2/STAT3 pathway in vitro and in vivo

Objective

To investigate the effect of β-Elemene (β-Ele) on the cisplatin sensitivity of OSCC cells and its mechanism in vitro and in vivo.

Methods

The human OSCC cell lines Tca-8113 and the cisplatin-resistant cell line Tca-8113-CDDP were cultured with β-Ele or/and cisplatin. The cytotoxicity of cisplatin or β-Ele, cell viability, cell cycles and apoptosis were detected. And the expression of JAK2/STAT3 related protein were detected. The xenograft tumor model of OSCC was established in nude mice and treated with cisplatin and/or β-Ele. The volume and weight of the transplanted tumor was measured, and the expression of p-JAK2 and p-STAT3 and cell apoptosis in the xenograft tumor tissues were detected.

Results

The combination of β-Ele and cisplatin significantly suppressed the cell proliferation, induced cell cycle arrest, promoted the apoptosis of Tca-8113-CDDP cells, and suppressed the activation of JAK2/STAT3 signaling pathway. The rescue experiments suggested that β-Ele enhanced cisplatin sensitivity via down-regulating JAK2/STAT3 signaling pathway. In vivo, β-Ele and cisplatin synergistically suppressed the tumor growth and induced apoptosis, and down-regulated the expression of p-JAK2 and p-STAT3.

Conclusions

β-Ele inhibits the cell viability and enhances the cisplatin sensitivity of OSCC by blocking the activation of JAK/STAT3 signaling pathway in vitro and in vivo, and the combination of β-Ele and cisplatin maybe a novel treatment for OSCC.

Role of STAT3 in the pathogenesis of nasopharyngeal carcinoma and its significance in anticancer therapy

Nasopharyngeal carcinoma (NPC) is a type of head and neck tumor with noticeable regional and ethnic differences. It is associated with Epstein-Barr virus infection and has a tendency for local and distant metastasis. NPC is also highly sensitive to radiotherapy and chemotherapy. Over 70% of patients present with locoregionally advanced disease, and distant metastasis is the primary reason for treatment failure. A signal transducer and activator of transcription 3 (STAT3) promotes NPC oncogenesis through mechanisms within cancerous cells and their interactions with the tumor microenvironment, which is critical in the initiation, progression, and metastasis of NPC. Further, p-STAT3 is strongly associated with advanced NPC. Recent research on STAT3 has focused on its expression at the center of various oncogenic pathways. Here, we discuss the role of STAT3 in NPC and its potential therapeutic inhibitors and analogs for the treatment and control of NPC.

β-elemene Isopropanolamine Derivative LXX-8250 Induces Apoptosis Through Impairing Autophagic Flux via PFKFB4 Repression in Melanoma Cells

Melanoma is a highly aggressive skin cancer and accounts for most of the skin cancer-related deaths. The efficacy of current therapies for melanoma remains to be improved. The isopropanolamine derivative of β-elemene LXX-8250 was reported to present better water solubility and stronger toxicity to tumor cells than β-elemene. Herein, LXX-8250 treatment showed 4-5-fold more toxicity to melanoma cells than the well-known anti-melanoma drug, Dacarbazine. LXX-8250 treatment induced apoptosis remarkably, which was caused by the impairment of autophagic flux. To clarify the molecular mechanism, microarray analyses were conducted, and PFKFB4 expression was found to be suppressed by LXX-8250 treatment. The cells overexpressed with PFKFB4 exhibited resistance to apoptosis induction and autophagic flux inhibition by LXX-8250 treatment. Moreover, LXX-8250 treatment suppressed glycolysis, to which the cells overexpressed with PFKFB4 were tolerant. LXX-8250 treatment inhibited the growth of melanoma xenografts and suppressed PFKFB4 expression and glycolysis in vivo. Taken together, LXX-8250 treatment induced apoptosis through inhibiting autophagic flux and glycolysis in melanoma cells, which was mediated by suppression of PFKFB4 expression. The study provides a novel strategy to melanoma treatment.

The roles of DNA methylation on the promotor of the Epstein–Barr virus (EBV) gene and the genome in patients with EBV-associated diseases

Abstract

Epstein–Barr virus (EBV) is an oncogenic virus that is closely associated with several malignant and lymphoproliferative diseases. Studies have shown that the typical characteristic of EBV-associated diseases is aberrant methylation of viral DNA and the host genome. EBV gene methylation helps EBV escape from immune monitoring and persist in host cells. EBV controls viral gene promoter methylation by hijacking host epigenetic machinery to regulate the expression of viral genes. EBV proteins also interact with host epigenetic regulatory factors to mediate the methylation of the host’s important tumour suppressor gene promoters, thereby participating in the occurrence of tumorigenesis. Since epigenetic modifications, including DNA methylation, are reversible in nature, drugs that target DNA methylation can be developed for epigenetic therapy against EBV-associated tumours. Various methylation modes in the host and EBV genomes may also be of diagnostic and prognostic value. This review summarizes the regulatory roles of DNA methylation on the promotor of EBV gene and host genome in EBV-associated diseases, proposes the application prospect of DNA methylation in early clinical diagnosis and treatment, and provides insight into methylation-based strategies against EBV-associated diseases.

Key points

• Methylation of both the host and EBV genomes plays an important role in EBV-associateddiseases.

• The functions of methylation of the host and EBV genomes in the occurrence and development of EBV-associated diseases are diverse.

• Methylation may be a therapeutic target or biomarker in EBV-associated diseases.

Crosstalk of LncRNA HOTAIR and SP1-mediated repression of PDK1 contributes to β-Elemene-inhibited proliferation of hepatocellular carcinoma cells

ETHNOPHARMACOLOGICAL RELEVANCE

Hepatocellular carcinoma (HCC) is a liver malignancy which lacks effective treatment and has a poor prognosis. β-Elemene refers to a natural Curcuma wenyujin-derived single molecular entity, which exhibits various biological activities, and is especially well-known for it's antitumor properties.

AIM OF THE RESEARCH

LncRNA HOTAIR, SP1, and PDK1 have displayed oncogenic roles in many tumors, participating in the initiation and progression of cancers by mediating multiple signaling pathways. However, there are only a few reports about their roles and mutual relationship in the growth of HCC cells. Therefore, this study aimed to investigate the expression of LncRNA HOTAIR, SP1, and PDK1 and their interaction with β-Elemene in HCC cells.

MATERIALS AND METHODS

MTT, a Colony formation assay, and flow cytometry were employed to evaluate the growth of HCC and LO2 cells under β-Elemene. LncRNA HOTAIR, SP1 and PDK1 plasmids were transfected into HCC cells by a transient transfection assay, and the expression and interaction of LncRNA HOTAIR, SP1 and PDK1 were assessed via qRT-PCR and western blotting.

RESULTS

β-Elemene suppressed HCC cell growth through the downregulation of LncRNA HOTAIR, SP1 and PDK1. The results demonstrated a reciprocal interaction among LncRNA HOTAIR, SP1 and PDK1. Exogenous overexpression LncRNA HOTAIR or SP1 eliminated the suppressive effects of β-Elemene on them, and both of which regulated PDK1 expression in HCC cells. Additionally, exogenously overexpressed SP1 or LncRNA HOTAIR prevented β-Elemene inhibition of the protein-level expression of PDK1, whereas overexpressing PDK1 had no effect on SP1, though it still weakened the inhibition of cell growth and LncRNA HOTAIR expression by β-Elemene.

CONCLUSION

β-Elemene suppresses HCC cell proliferation via through the regulation of LncRNA HOTAIR, SP1, PDK1 and their interaction.

Natural Bioactive Compounds Targeting Epigenetic Pathways in Cancer: A Review on Alkaloids, Terpenoids, Quinones, and Isothiocyanates

Cancer is one of the most complex and systemic diseases affecting the health of mankind, causing major deaths with a significant increase. This pathology is caused by several risk factors, of which genetic disturbances constitute the major elements, which not only initiate tumor transformation but also epigenetic disturbances which are linked to it and which can induce transcriptional instability. Indeed, the involvement of epigenetic disturbances in cancer has been the subject of correlations today, in addition to the use of drugs that operate specifically on different epigenetic pathways. Natural molecules, especially those isolated from medicinal plants, have shown anticancer effects linked to mechanisms of action. The objective of this review is to explore the anticancer effects of alkaloids, terpenoids, quinones, and isothiocyanates.

Elemene Nanoemulsion Inhibits Metastasis of Breast Cancer by ROS Scavenging

Introduction

Elemene (C₁₅H₂₄) is a sesquiterpene compound extracted from the rhizome of Curcuma herbs. In the past decades, the anti-tumor activity of elemene has been observed in vitro and in some clinical practices. However, pharmacological mechanisms of elemene are not demonstrated adequately, which may lead to improper clinical applications. This study aimed to investigate the anti-tumor effect of elemene nanoemulsion in the mouse model of triple-negative breast cancer (TNBC) and reveal the underlying mechanisms.

Methods

The ESR measurement and quantum mechanics simulation were used to characterize the antioxidant ability of elemene nanoemulsion. The murine breast cancer cell line 4T1 cells were inoculated subcutaneously into the left fourth mammary fat pad of BalB/c mice to establish a TNBC mice model. The H&E staining, immunohistochemical staining, DHE staining and Western blot were employed to evaluate the therapeutic effects of the elemene nanoemulsion on the TNBC mice.

Results

It was shown that the elemene nanoemulsion prolonged the survival of the triple-negative breast cancer-bearing mice and inhibited the metastasis to lung and liver while did not induce significant cytotoxicity to the tumor cells. Mechanistic studies demonstrated that the elemene nanoemulsion effectively scavenged the reactive oxygen species (ROS) in vitro and in vivo, which decreased the stabilization of hypoxia-inducible factor-1α (HIF-1α) and consequently reduced angiogenesis in the tumor microenvironment as well as decreased the level of NLRP3 inflammasomes and IL-1β production. In addition, the elemene nanoemulsion downregulated the level of IL-1β in the RAW264.7 cells in exposure with LPS.

Conclusion

In conclusion, due to the ROS scavenging ability, elemene nanoemulsion effectively inhibited the metastasis of the breast cancer cells to lung and liver and consequently prolonged the survival of TNBC mice.

Preparation, characterization, pharmacokinetics and anticancer effects of PEGylated β-elemene liposomes

Objective: This study aimed to develop a new polyethylene glycol (PEG)ylated β-elemene liposome (PEG-Lipo-β-E) and evaluate its characterization, pharmacokinetics, antitumor effects and safety in vitro and in vivo.

Methods: The liposomes were prepared by ethanol injection and high-pressure micro-jet homogenization. Characterization of the liposomes was conducted, and drug content, entrapment efficiency (EE), in vitro release and stability were studied by ultra-fast liquid chromatography (UFLC) and a liquid surface method. Blood was drawn from rats to establish the pharmacokinetic parameters. The anticancer effect was evaluated in a KU-19-19 bladder cancer xenograft model. Histological analyses were performed to evaluate safety.

Results: The PEG-Lipo-β-E showed good stability and was characterized as 83.31 ± 0.181 nm in size, 0.279 ± 0.004 in polydispersity index (PDI), −21.4 ± 1.06 mV in zeta potential, 6.65 ± 0.02 in pH, 5.024 ± 0.107 mg/mL in β-elemene (β-E) content, and 95.53 ± 1.712% in average EE. The Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) indicated the formation of PEG-Lipo-β-E. Compared to elemene injection, PEG-Lipo-β-E demonstrated a 1.75-fold decrease in clearance, a 1.62-fold increase in half-life, and a 1.76-fold increase in area under the concentration-time curves (AUCs) from 0 hour to 1.5 hours (P < 0.05). PEG-Lipo-β-E also showed an enhanced anticancer effect in vivo. Histological analyses showed that there was no evidence of toxicity to the heart, kidney, liver, lung or spleen.

Conclusions: The present study demonstrates PEG-Lipo-β-E as a new formulation with ease of preparation, high EE, good stability, improved bioavailability and antitumor effects.

Investigation on the Efficiency of Chinese Herbal Injections combined with Concurrent Chemoradiotherapy for Treating Nasopharyngeal Carcinoma based on Multidimensional Bayesian Network Meta-analysis

Introduction: Given the wide utilization of Chinese herbal injections in the treatment of nasopharyngeal carcinoma (NPC), this network meta-analysis (NMA) was devised to compare the clinical efficacy and safety of different Chinese herbal injections combined with concurrent chemoradiotherapy (CCRT) against NPC.

Methods: Randomized controlled trials (RCTs) were retrieved from seven electronic databases from the date of database establishment to October 5, 2020. Study selection and data extraction conformed to a priori criteria. Focusing on clinical effective rate, performance status, grade ≥3 oral mucositis, nausea and vomiting, leukopenia, and thrombopenia, this NMA was performed with Review Manager 5.3.5, Stata 13.1, WinBUGS 1.4.3, and R 4.0.3 software.

Results: Ten inventions from 37 RCTs involving 2,581 participants with NPC that evaluated the clinical effective rate, nausea and vomiting, leukopenia, thrombopenia, and grade ≥3 oral mucositis were included. Compared with CCRT alone, Elemene injection and Compound Kushen injection were associated with significantly improved clinical effective rates, and Elemene injection plus CCRT had the highest probability in terms of clinical effective rate (78.07%) compared with the other interventions. Shenqifuzheng injection, Xiaoaiping injection, and Shenmai injection ranked the best in terms of performance status (79.02%), nausea and vomiting (86.35%), and grade ≥3 oral mucositis (78.14%) when combined with CCRT. Kangai injection combined with CCRT ranked ahead of the other injections in terms of leukopenia (90.80%) and thrombopenia (91.04%), and had a better impact on improving performance status and reducing leukopenia, thrombopenia, grade ≥3 oral mucositis, and nausea and vomiting in the multidimensional cluster analysis.

Conclusion: Current clinical evidence indicates that Elemene injection combined with CCRT has the best clinical effective rate and that Kangai injection might have a comprehensively better impact on improving performance status and reducing adverse reactions against NPC. Additionally, due to the limitations of this NMA, more multicenter, high-quality, and head-to-head RCTs are needed to properly support our findings.

A Comprehensive Mini-Review of Curcumae Radix: Ethnopharmacology, Phytochemistry, and Pharmacology

Curcumae Radix is an efficacious ingredient with various medicinal properties empirically used in traditional Chinese medicine (TCM) formula for the treatment of cancer, depression, chest pain, dysmenorrhea, epilepsy, and jaundice. However, either phytochemical or pharmacological information of Curcumae Radix underlying its traditionally medicinal uses is rarely summarized and systematically analyzed. To provide evidence for clinical trials, a comprehensive literature review has been prepared of the phytochemicals, and ethnopharmacological and pharmacological mechanisms of this herb. The review approach consisted of searching several web-based scientific databases, including PubMed, Web of Science, and Elsevier. The keywords included “Curcumae Radix,” “ Curcuma wenyujin,” “ Curcuma longa,” “ Curcuma kwangsiensis,” and “ Curcuma phaeocaulis.” Based on the proposed criteria, 57 articles were evaluated in detail. The accumulated data indicate that Curcumae Radix contains a number of bioactive phytochemicals, mainly sesquiterpenes, diarylheptanoids, and diarylpentanoids, which account for a variety of medicinal values, such as anticancer, anti-inflammation, anti-hepatic fibrosis, and antioxidant. A wide range of apoptotic proteins, cell adhesion molecules, inflammatory cytokines, and enzymic and nonenzymic antioxidants could be modulated by either Curcumae Radix or its bioactive compounds, thus underpinning a fundamental understanding for the pharmacological effects of this herb. This review highlights the therapeutic potential of Curcumae Radix to progress the development of versatile adjuvants or therapeutic agents in the future.

Preclinical efficacy of ribavirin in SHH and group 3 medulloblastoma

OBJECTIVE

Medulloblastoma, the most common pediatric brain malignancy, has Sonic Hedgehog (SHH) and group 3 (Myc driven) subtypes that are associated with the activity of eukaryotic initiation factor 4E (eIF4E), a critical mediator of translation, and enhancer of zeste homolog 2 (EZH2), a histone methyltransferase and master regulator of transcription. Recent drug repurposing efforts in multiple solid and hematologic malignancies have demonstrated that eIF4E and EZH2 are both pharmacologically inhibited by the FDA-approved antiviral drug ribavirin. Given the molecular overlap between medulloblastoma biology and known ribavirin activity, the authors investigated the preclinical efficacy of repurposing ribavirin as a targeted therapeutic in cell and animal models of medulloblastoma.

METHODS

Multiple in vitro assays were performed using human ONS-76 (a primitive SHH model) and D425 (an aggressive group 3 model) cells. The impacts of ribavirin on cellular growth, death, migration, and invasion were quantified using proliferation and Cell Counting Kit-8 (CCK-8) assays, flow cytometry with annexin V (AnnV) staining, scratch wound assays, and Matrigel invasion chambers, respectively. Survival following daily ribavirin treatment (100 mg/kg) was assessed in vivo in immunodeficient mice intracranially implanted with D425 cells.

RESULTS

Compared to controls, ribavirin treatment led to a significant reduction in medulloblastoma cell growth (ONS-76 proliferation assay, p = 0.0001; D425 CCK-8 assay, p < 0.0001) and a significant increase in cell death (flow cytometry for AnnV, ONS-76, p = 0.0010; D425, p = 0.0284). In ONS-76 cells, compared to controls, ribavirin significantly decreased cell migration and invasion (Matrigel invasion chamber assay, p = 0.0012). In vivo, ribavirin significantly extended survival in an aggressive group 3 medulloblastoma mouse model compared to vehicle-treated controls (p = 0.0004).

CONCLUSIONS

The authors demonstrate that ribavirin, a clinically used drug known to inhibit eIF4E and EZH2, has significant antitumor effects in multiple preclinical models of medulloblastoma, including an aggressive group 3 animal model. Ribavirin may represent a promising targeted therapeutic in medulloblastoma.

Anti-Tumor Drug Discovery Based on Natural Product β-Elemene: Anti-Tumor Mechanisms and Structural Modification

Natural products are important sources for drug discovery, especially anti-tumor drugs. β-Elemene, the prominent active ingredient extract from the rhizome of Curcuma wenyujin, is a representative natural product with broad anti-tumor activities. The main molecular mechanism of β-elemene is to inhibit tumor growth and proliferation, induce apoptosis, inhibit tumor cell invasion and metastasis, enhance the sensitivity of chemoradiotherapy, regulate the immune system, and reverse multidrug resistance (MDR). Elemene oral emulsion and elemene injection were approved by the China Food and Drug Administration (CFDA) for the treatment of various cancers and bone metastasis in 1994. However, the lipophilicity and low bioavailability limit its application. To discover better β-elemene-derived anti-tumor drugs with satisfying drug-like properties, researchers have modified its structure under the premise of not damaging the basic scaffold structure. In this review, we comprehensively discuss and summarize the potential anti-tumor mechanisms and the progress of structural modifications of β-elemene.

β-elemene suppresses the malignant behavior of esophageal cancer cells by regulating the phosphorylation of AKT

BACKGROUND

Esophageal cancer is a digestive tract malignancy, ranking sixth among the world's deadliest tumor incidence. However, the pathogenesis of esophageal cancer is complex and the prognosis remains poor. Therefore, in-depth study of the pathogenesis and developing effective treatments are of great value for esophageal cancer. β-elemene is a natural monomeric compound derived from the Chinese herbal Curcuma wenyujin. β-elemene has been reported to have anti-tumor effects and used as an adjunct to clinical therapy for multiple cancers. This study aims to explore the effects of β-elemene on esophageal cancer and its related molecular mechanisms.

METHODS

TE-1 and KYSE-150 cells were used to evaluate the activity of β-elemene on esophageal cancerin vitro and in vivo. Western blot was performed for protein expression assessment. CCK8 assay and cell cycle analysis were used for proliferation testing. Flow cytometry was performed for apoptosis detection. Wound healing assay was subjected to assess the migration ability. Transwell chamber assay was applied to assess the invasion ability. HE staining, TUNEL staining and immunohistochemical staining were used to evaluate the changes in tumor tissues.

RESULTS

We found that β-elemene treatment suppressed proliferation, as well as induced apoptosis of esophageal cancer cells. In addition, β-elemene inhibited the migration and invasion ability of esophageal cancer cells. Furthermore, β-elemene exerted its effects against esophageal cancer by specifically regulating AKT signaling, thereby controlling the expression of PD-L1.

CONCLUSION

β-elemene inhibits proliferation and metastasis of esophageal cancer cells by regulating the phosphorylation of AKT.

β-elemene enhances cisplatin-induced apoptosis in bladder cancer cells through the ROS-AMPK signaling pathway

Cisplatin-based chemotherapy is the standard regimen for patients with bladder cancer, but its effectiveness is limited by high toxicity and the development of drug resistance. β-elemene (β-ELE), a compound extracted from Rhizoma zedoariae, has antitumor activity in various malignancies and exhibits low toxicity. However, the effects and specific mechanism of β-ELE in bladder cancer remain unclear. The present study aimed to investigate the antitumor activity and possible mechanisms of β-ELE alone and in combination with cisplatin in bladder cancer cells. Cell viability was determined using Cell Counting Kit-8. Cell cycle and reactive oxygen species (ROS) analyses were performed by flow cytometry. Apoptosis was detected by Hoechst 33258 and Annexin-V/propidium iodide staining. Mitochondrial membrane potential was determined by staining with a JC-1 probe, flow cytometry and fluorescence microscopy. Protein expression was detected by western blotting. The results revealed that β-ELE significantly inhibited the proliferation of various bladder cancer cell lines and induced cell cycle arrest at G₀/G₁-phase in T24 and 5637 cells. Compared with cisplatin alone, co-treatment with β-ELE increased cisplatin-mediated cytotoxicity against T24 cells, which resulted in the loss of mitochondrial membrane potential and release of cytochrome c into the cytoplasm. Co-treatment with β-ELE and cisplatin enhanced ROS accumulation and activation of 5′AMP-activated protein kinase (AMPK), which induced apoptosis. The results of the present study suggested that β-ELE inhibited the proliferation of bladder cancer cells in vitro and enhanced cisplatin-induced mitochondria-dependent apoptosis via the ROS-AMPK signaling pathway. Combination therapy with β-ELE requires further investigation as a potential treatment of bladder cancer.

Multi-Targeting by β-Elemene and Its Anticancer Properties: A Good Choice for Oncotherapy and Radiochemotherapy Sensitization

Several studies have focused on chemical agents, tailored from natural edible products, used to prevent and treat various diseases. β-elemene is a well-known compound derived from Curcuma wenyujin that possesses a wide spectrum of anticancer properties under preclinical and clinical conditions. Several studies have demonstrated its inhibitory effect both in humans and animals with cancers. Numerous in vivo and in vitro experimental models have revealed that β-elemene can modulate multiple molecular pathways involved in carcinogenesis. In general, (1) β-elemene itself can inhibit and kill tumor cells through a variety of mechanisms, and (2) can synergistically enhance the effect of radiotherapy and/or chemotherapy, (3) also can regulate autoimmune in the treatment of tumors. In this article, we critically focused on the available scientific evidence discussing the use of β-elemene in cancer prevention, and its molecular targets and mechanisms of action in different types of cancer. In addition, we have discussed its sources, chemistry, bioavailability, and future research directions.

EZH2 promotes invasion and tumour glycolysis by regulating STAT3 and FoxO1 signalling in human OSCC cells

The enhancer of zeste homolog 2 (EZH2), known as a member of the polycomb group (PcG) proteins, is an oncogene overexpressed in a variety of human cancers. Here, we found that EZH2 correlated with poor survival of oral squamous cell carcinoma (OSCC) patients using immunohistochemistry staining. EZH2 overexpression led to a significant induction in tumour glycolysis, Epithelial‐mesenchymal transition (EMT), migration and invasion of OSCC cells. Conversely, silencing of EZH2 inhibited tumour glycolysis, EMT, migration and invasion in OSCC cells. Ectopic overexpression of EZH2 increased phosphorylation of STAT3 at pY705 and decreased FoxO1 expression, and FoxO1 expression was enhanced when inhibiting STAT3. In addition, EZH2 overexpression led to a significant decrease in FoxO1 mRNA levels in nude mice xenograft. These results indicated that regulation of EZH2 might have the potential to be targeted for OSCC treatment.

Molecular targets of β-elemene, a herbal extract used in traditional Chinese medicine, and its potential role in cancer therapy: A review

β-Elemene is a sesquiterpene compound extracted from the herb Curcuma Rhizoma and is used in traditional Chinese medicine (TCM) to treat several types of cancer, with no reported severe adverse effects. Recent studies, using in vitro and in vivo studies combined with molecular methods, have shown that β-elemene can inhibit cell proliferation, arrest the cell cycle, and induce cell apoptosis. Recent studies have identified the molecular targets of β-elemene that may have a role in cancer therapy. This review aims to discuss the anticancer potential of β-elemene through its actions on several molecular targets including kinase enzymes, transcription factors, growth factors and their receptors, and proteins. β-Elemene also regulates the expression of several key molecules that are involved in tumor angiogenesis and metastasis including vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMPs), E-cadherin, N-cadherin, and vimentin. Also, β-elemene has been shown to have regulatory effects on the immune response and increases the sensitivity of cancer cells to chemoradiotherapy and has shown effects on multidrug resistance (MDR) in malignancy. Recent studies have shown that β-elemene can induce autophagy, which prevents cancer cells from undergoing apoptosis. Therefore, the molecular mechanisms for the treatment effects on cancer of the herbal extract, β-elemene, which has been used for centuries in traditional Chinese medicine, are now being studied and identified.

Regulation of signaling pathways by β-elemene in cancer progression and metastasis

Entry of β-elemene into various phases of clinical trials advocates its significance as a premium candidate likely to gain access to mainstream medicine. Based on the insights gleaned from decades of research, it seems increasingly transparent that β-elemene has shown significant ability to modulate multiple cell signaling pathways in different cancers. We partition this multicomponent review into how β-elemene strategically modulates various signal transduction cascades. We have individually summarized regulation of tumor necrosis factor related apoptosis-inducing ligand, signal transducers and activators of transcription, transforming growth factor/SMAD, NOTCH, and mammalian target of rapamycin pathways by β-elemene. Last, we will discuss the results of clinical trials of β-elemene and how effectively we can use these findings to stratify patients who can benefit most from β-elemene.

Antitumor effects of β-elemene via targeting the phosphorylation of insulin receptor

Ewing sarcoma family tumors (ESFTs) are a group of aggressive and highly metastatic tumors lacking efficient therapies. Insulin-like growth factor 1 receptor (IGF1R) blockade is one of the most efficient targeting therapy for ESFTs. However, the appliance is obstructed by drug resistance and disease recurrence due to the activation of insulin receptor (IR) signaling induced by IGF1R blockade. Herein β-elemene, a compound derived from natural plants, exhibited a remarkable proliferation repression on ESFT cells, which was weakened by a caspase inhibitor Z-VAD. β-elemene in combination with IGF1R inhibitors enhanced markedly the repression on cellular proliferation and mTOR activation by IGF1R inhibitors and suppressed the PI3K phosphorylation induced by IGF1R inhibitors. To investigate the mechanisms, we focused on the effects of β-elemene on IR signaling pathway. β-elemene significantly suppressed the insulin-driven cell growth and the activation of mTOR and PI3K in tumor cells, while the toxicity to normal hepatocytes was much lower. Further, the phosphorylation of IR was found to be suppressed notably by β-elemene specifically in tumor cells other than normal hepatocytes. In addition, β-elemene inhibited the growth of ESFT xenografts in vivo, and the phosphorylation of IR and S6 ribosomal protein was significantly repressed in the β-elemene-treated xenografts. These data suggest that β-elemene targets IR phosphorylation to inhibit the proliferation of tumor cells specifically and enhance the effects of IGF1R inhibitors. Thus, this study provides evidence for novel approaches by β-elemene alone or in combination with IGF1R blockades in ESFTs and IR signaling hyperactivated tumors.

β‑elemene inhibits oxygen‑induced retinal neovascularization via promoting miR‑27a and reducing VEGF expression

The present study aimed to investigate the significant role of β-elemene in mouse models of oxygen-induced retinopathy (OIR). C57BL/6J neonatal mice were used to establish OIR models. They were divided into four groups: Normoxia, OIR, OIR control and OIR‑treated. Mice in the OIR group were exposed to 75±5% oxygen for 5 days and returned to a normal oxygen environment on postnatal day 12 (P12). The OIR treated group was intravitreally injected with 1 µl β‑elemene on P12 and subsequently returned to a normal oxygen environment for 5 days (P12‑P17). Retinas were obtained on P17. Retinal neovascularization (RNV) was detected using adenosine diphosphatase staining and analyzed by counting the nuclei of neovascular endothelial cells. Vascular endothelial growth factor (VEGF) expression was determined by reverse transcription‑quantitative polymerase chain reaction, immunohistochemistry and western blot analysis. MicroRNA (miRNA/miR) microarrays were used to screen out differentially expressed miRNAs between the OIR and β‑elemene‑treated groups. Binding the 3'‑untranslated region (UTR) of VEGF and miR‑27a was confirmed using luciferase assays. It was found that high oxygen concentrations accelerated RNV and increased the number of preretinal neovascular cells; β‑elemene treatment reduced these effects. VEGF mRNA and protein expression was higher in the OIR and OIR control groups, compared with the normoxia and OIR‑treated groups. Further, it was shown that miR‑22, miR‑181a‑1, miR‑335‑5p, miR‑669n, miR‑190b, miR‑27a and miR‑93 were upregulated in the OIR‑treated group, and downregulated in the OIR group. The prediction websites TargetScan and miRanda revealed that VEGF contained a potential miR‑27a binding site in its 3'‑untranslated region (UTR). Luciferase assays demonstrated that miR‑27a directly bound to the 3'‑UTR of VEGF. In vitro experiments demonstrated that miR‑27a inhibited VEGF expression. In addition, β‑elemene treatment upregulate miR‑27a expression in vivo and in vitro. When miR‑27a expression was depleted by miR‑27a inhibitor, the protective effect of β‑elemene on RNV was eliminated. The present study demonstrated that β‑elemene reduced RNV in mouse OIR models via miR‑27a upregulation, leading to reduced VEGF expression. This finding may contribute to the development of novel therapeutic strategies for human retinopathy.

Inactivation of Stat3 and crosstalk of miRNA155-5p and FOXO3a contribute to the induction of IGFBP1 expression by beta-elemene in human lung cancer

β-Elemene, an active component of natural plants, has been shown to exhibit anticancer properties. However, the detailed mechanism underlying these effects has yet to be determined. In this study, we show that β-elemene inhibits the growth of lung cancer cells. Mechanistically, we found that β-elemene decreased the phosphorylation of signal transducer and activator of transcription 3 (Stat3) and miRNA155-5p mRNA but induced the protein expression of human forkhead box class O (FOXO)3a; the latter two were abrogated in cells with overexpressed Stat3. Notably, miRNA155-5p mimics reduced FOXO3a luciferase reporter activity in the 3-UTR region and protein expression, whereas overexpressed FOXO3a countered the reduction of the miRNA155-5p levels by β-elemene. Moreover, β-elemene increased the mRNA and protein expression levels as well as promoter activity of insulin-like growth factor-binding protein 1 (IGFBP1); this finding was not observed in cells with a silenced FOXO3a gene and miRNA155-5p mimics. Finally, silencing of IGFBP1 blocked β-elemene-inhibited cell growth. Similar findings were observed in vivo. In summary, our results indicate that β-elemene increases IGFBP1 gene expression via inactivation of Stat3 followed by a reciprocal interaction between miRNA155-5p and FOXO3a. This effect leads to inhibition of human lung cancer cell growth. These findings reveal a novel molecular mechanism underlying the inhibitory effects of β-elemene on lung cancer cells.

A compound found in one Chinese medicinal herb inhibits the growth of lung cancer cells by indirectly activating a protein with anti-proliferative properties. Hann and colleagues from the Guangzhou University of Chinese Medicine, China, uncovered the molecular pathways by which β-elemene, a natural compound isolated from the Curcuma wenyujin plant, mediates the anti-cancer effects. They showed that β-elemene inactivates the two important regulatory molecules, one protein and another small RNA, while also inducing the expression of one protein that promotes in killing cancer cells. These changes lead to elevated levels of the protein that prevents cell invasion and spread. Collectively, this altered signaling inside the lung cancer cell lead to reduced growth, in both cell-based culture and mouse model. The findings help explain why β-elemene has potential as a therapeutic agent in lung cancer.

DNMT1 modulates interneuron morphology by regulating Pak6 expression through crosstalk with histone modifications

Epigenetic mechanisms of gene regulation, including DNA methylation and histone modifications, call increasing attention in the context of development and human health. Thereby, interactions between DNA methylating enzymes and histone modifications tremendously multiply the spectrum of potential regulatory functions. Epigenetic networks are critically involved in the establishment and functionality of neuronal circuits that are composed of gamma-aminobutyric acid (GABA)-positive inhibitory interneurons and excitatory principal neurons in the cerebral cortex. We recently reported a crucial role of the DNA methyltransferase 1 (DNMT1) during the migration of immature POA-derived cortical interneurons by promoting the migratory morphology through repression of Pak6. However, the DNMT1-dependent regulation of Pak6 expression appeared to occur independently of direct DNA methylation. Here, we show that in addition to its DNA methylating activity, DNMT1 can act on gene transcription by modulating permissive H3K4 and repressive H3K27 trimethylation in developing inhibitory interneurons, similar to what was found in other cell types. In particular, the transcriptional control of Pak6, interactions of DNMT1 with the Polycomb-repressor complex 2 (PCR2) core enzyme EZH2, mediating repressive H3K27 trimethylations at regulatory regions of the Pak6 gene locus. Similar to what was observed upon Dnmt1 depletion, inhibition of EZH2 caused elevated Pak6 expression levels accompanied by increased morphological complexity, which was rescued by siRNA-mediated downregulation of Pak6 expression. Together, our data emphasise the relevance of DNMT1-dependent crosstalk with histone tail methylation for transcriptional control of genes like Pak6 required for proper cortical interneuron migration.

β-elemene against Burkitt's lymphoma via activation of PUMA mediated apoptotic pathway

Burkitt's lymphoma is a type of highly aggressive Non-Hodgkin's lymphoma. Although advanced Burkitt's lymphoma is responsive to high-intensity chemotherapy regimens, increasing systemic toxicity, tumor recurrence and metastasis significantly reduce the patient survival. Thus, it is important to investigate novel antitumor agents with safety and effectiveness. β-elemene shows anti-proliferative effect on cancer cells by triggering apoptosis through regulating several molecular signaling pathways. However, its role in the suppression of Burkitt's lymphoma has not yet been fully elucidated. The inhibitory effect of β-elemene in Burkitt's lymphoma was studied in vitro and in vivo, as well as the involved molecular mechanism. The results demonstrated that β-elemene effectively inhibited the growth and induced the apoptosis of Burkitt's lymphoma cells through upregulation of PUMA expression and modulating PUMA related apoptotic signaling pathway. The in vivo data confirmed the anti-tumor effect of β-elemene in the xenografts, suggesting that β-elemene is associated with PUMA activation, leading to Bax and caspase induction and onset of mitochondrial apoptosis.

Phosphatidylinositol 3-Kinase-DNA Methyltransferase 1-miR-1281-Histone Deacetylase 4 Regulatory Axis Mediates Platelet-Derived Growth Factor-Induced Proliferation and Migration of Pulmonary Artery Smooth Muscle Cells

BACKGROUND

Platelet-derived growth factor BB, a potent mitogen of pulmonary artery smooth muscle cells (PASMCs), has been implicated in pulmonary arterial remodeling, which is a key pathogenic feature of pulmonary arterial hypertension. Previous microRNA profiling in platelet-derived growth factor BB-treated PASMCs found a significantly downregulated microRNA, miR-1281, but it has not been associated with any cellular function, and we investigated the possibility.

METHODS AND RESULTS

Real-time quantitative reverse transcription-polymerase chain reaction assay proved that downregulation of miR-1281 was a conserved phenomenon in human and rat PASMCs. Overexpression and inhibition of miR-1281 in PASMCs promoted and suppressed, respectively, the cell proliferation and migration. Bioinformatic prediction and 3'-untranslated region reporter assay identified histone deacetylase 4 to be a direct target of miR-1281. Supporting this, proliferation and migration assay demonstrated the cellular function of histone deacetylase 4 is inversely correlated with that of miR-1281. Mechanistically, it is found that platelet-derived growth factor BB activates the phosphatidylinositol 3-kinase pathway, which then induces the expression of DNA methyltransferase 1, leading to enhanced methylation of a flanking CpG island and repressed miR-1281 expression. Finally, a reduced miR-1281 level was consistently identified in hypoxic PASMCs in vitro, in pulmonary arteries of rats with monocrotaline-induced pulmonary arterial hypertension, and in serum of patients with coronary heart disease-pulmonary arterial hypertension. These data suggest that there may be a diagnostic and therapeutic use for miR-1281.

CONCLUSIONS

Herein, we report a novel regulatory axis, phosphatidylinositol 3-kinase-DNA methyltransferase 1-miR-1281-histone deacetylase 4, integrating multiple epigenetic regulators that participate in platelet-derived growth factor BB-stimulated PASMC proliferation and migration and pulmonary vascular remodeling.

HOTAIR-mediated reciprocal regulation of EZH2 and DNMT1 contribute to polyphyllin I-inhibited growth of castration-resistant prostate cancer cells in vitro and in vivo

BACKGROUND

Polyphyllin I (PPI), one of the steroidal saponins in paris polyphylla, has been reported to exhibit antitumor effects. However, the detailed molecular mechanism underlying this has not been elucidated.

METHODS

Cell viability and cell cycle distribution were measured using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and Flow cytometry assays, respectively. Cell invasion and migration were examined by Transwell invasion and wound healing assays. Western blot analysis was performed to examine the protein expressions of zeste homolog 2 (EZH2), DNA methyltransferase 1 (DNMT1). QRT-PCR was used to examine the levels of long non-coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR). Small interfering RNAs (siRNAs) method was used to knockdown HOTAIR. Exogenously expressions of HOTAIR, DNMT1 and EZH2 were carried out by Transient transfection assays. EZH2 promoter activity was measured by Secrete-Pair Dual Luminescence Assay Kit. A nude mice xenograft model was used to confirm the findings in vitro.

RESULTS

We showed that PPI significantly inhibited growth, induced cell cycle arrest of castration-resistant prostate cancer (CRPC) cells. In addition, PPI also reduced the migration and invasion in CRPC cells. In mechanism, we found that PPI decreased the protein expressions of EZH2, DNMT1 and levels of HOTAIR. Interestingly, silenced HOTAIR reduced EZH2 and DNMT1 protein expressions. On the contrary, exogenously expressed HOTAIR resisted PPI-inhibited EZH2 and DNMT1 protein expressions, EZH2 promoter activity and cell growth. Moreover, excessive EZH2 antagonized PPI-suppressed DNMT1 protein expression or vice versa. Consistent with this, PPI inhibited tumor growth, HOTAIR, the protein expressions of DNMT1 and EZH2 in vivo.

CONCLUSION

Our results show that PPI inhibits growth of CRPC cells through inhibition of HOTAIR expression, subsequently; this results in the repression of DNMT1 and EZH2 expressions. The interactions among HOTAIR, DNMT1 and EZH2, and reciprocal regulation of DNMT1 and EZH2 contribute to the overall responses of PPI. This study reveals a novel mechanism for HOTAIR-mediated regulating DNMT1 and EZH2 in response to PPI in inhibition of the growth of CRPC cells.

Expression of EZH2 in endometrial carcinoma and its effects on proliferation and invasion of endometrial carcinoma cells

Expression of enhancer of zeste homolog 2 (EZH2) has been implicated in cancer pathology, but research on its mechanistic activity is limited. The present study sought to assess the levels expression of EZH2 in patients with endometrial carcinoma (EC) and to explore the effects of EZH2 downregulation on the biological behavior of endometrial carcinoma RL-952 cells. Samples were obtained from a total of 104 patients with EC and an immunohistochemical assay was used to detect the expression of EZH2 in cancer and adjacent tissues. The relationship between the expression of EZH2 and the clinicopathological features was analyzed. Endometrial carcinoma RL-952 cells were transfected with chemically synthesized siRNA to conduct targeting inhibition of EZH2 expression. The expression levels of EZH2 protein were detected by immunoblotting. MTT and Transwell assays were used to detect the changes of cell proliferation and invasion after EZH2 downregulation. Of the 104 cases of endometrial carcinoma samples, 71 cases showed positive expression of EZH2, with an expression rate of 68.27%. In 104 cases of adjacent tissue samples, 25 cases showed positive expression of EZH2, with an expression rate of 24.03%. The expression of EZH2 in endometrial carcinoma tissue was significantly higher than that in adjacent tissue (P<0.05). The expression of EZH2 in endometrial carcinoma tissue was not correlated with the menopausal status and age of patients (P>0.05), but was correlated with the histological grade, depth of tumor invasion, lymph node metastasis and TNM stage (P<0.05). The expression of E2H2 was significantly downregulated by si-E2H2 and the proliferation and invasion abilities of cells were significantly reduced after EZH2 downregulation (P<0.05). EZH2 is closely related to the development of endometrial carcinoma and can enhance the proliferative activity of endometrial carcinoma RL-952 cells and promote cell invasion.

Correlation of the expressions of IGF1R-RACK1-STAT3 and Bcl-xl in nasopharyngeal carcinoma with the clinicopathological features and prognosis of nasopharyngeal carcinoma

The aim of this study was to investigate the correlation of expression of IGF1R-RACK1-STAT3 and Bcl-xl in nasopharyngeal carcinoma (NPC) with the clinicopathological features and the prognosis of NPC. Our study selected 215 NPC tissues and 178 chronic nasopharyngitis tissues (control group). Positive expression rates of IGF1R, RACK1, STAT3, and Bcl-xl were tested by immunohistochemical method, and expression of IGF1R, RACK1, STAT3, Bcl-xl, Bcl-2, and Bax by western blotting. Correlation of IGF1R, RACK1, STAT3, and Bcl-xl with the clinicopathological features of NPC was analyzed. The correlation among those four expression was analyzed by Spearman. The survival of NPC and independent factors of prognosis were tested by Kaplan-Meier and COX proportional hazards model respectively. The NPC group had higher positive expression rates of IGF1R, RACK1, STAT3, and Bcl-xl, and elevated expression of IGF1R, RACK1, STAT3, Bcl-xl, Bcl-2, and Bax. The lymph node metastasis (LNM) group had higher positive expression rates of IGF1R and RACK1 when compared with the non-LNM group. Patients with stage III and IV had higher positive expression rates of IGF1R, RACK1, STAT3, and Bcl-xl. There was positive correlation between expression of IGF1R and RACK1, STAT3. Such correlation was found between RACK1 and STAT3. Patients with negative expression of IGF1R, RACK1, STAT3, and Bcl-xl had higher survival rates. The risky factors of poor prognosis of NPC were positive expression of IGF1R, RACK1, STAT3 and Bcl-xl, and LNM. IGF1R-RACK1-STAT3 and Bcl-xl expression correlated with the clinicopathological features and poor prognosis of NPC.