Toosendanin suppresses oncogenic phenotypes of human gastric carcinoma SGC-7901 cells partly via miR-200a-mediated downregulation of β-catenin pathway

Toosendanin: upgrade of an old agent in cancer treatment

Toosendanin (TSN), a tetracyclic triterpenoid derived from Melia toosendan and M. azedarach, demonstrates broad application prospects in cancer treatment. Although previously employed as a pesticide, recent studies have revealed its potential therapeutic value in treating various types of cancer. TSN exerts an anticancer effect via mechanisms including proliferation inhibition, apoptosis induction, migration suppression, and angiogenesis inhibition. However, TSN's toxicity, particularly its hepatotoxicity, significantly limits its therapeutic application. This review explored the dual nature of TSN, evaluating both its anticancer potential and toxicological risks, emphasizing the importance of balancing these aspects in therapeutic applications. Furthermore, we investigated the incorporation of TSN into novel therapeutic strategies, such as Proteolysis-targeting chimeras (PROTAC) technology and nanotechnology-based drug delivery systems (DDS), which enhance treatment efficacy while mitigating toxicity in normal tissues.

Therapeutic potential of toosendanin: Novel applications of an old ascaris repellent as a drug candidate

Toosendanin (TSN), extracted from Melia. toosendan Sieb.et Zucc. and Melia. azedarach L., has been developed into an ascaris repellent in China. However, with the improvement of public health protection, the incidence of ascariasis has been reduced considerably, resulting in limited medical application of TSN. Therefore, it is questionable whether this old ascaris repellent can develop into a drug candidate. Modern studies have shown that TSN has strong pharmacological activities, including anti-tumor, anti-botulinum, anti-viral and anti-parasitic potentials. It also can regulate fat formation and improve inflammation. These researches indicate that TSN has great potential to be developed into a corresponding medical product. In order to better development and application of TSN, the availability, pharmacodynamics, pharmacokinetics and toxicology of TSN are summarized systematically. In addition, this review discusses shortcomings in the current researches and provides useful suggestions about how TSN developed into a drug candidate. Therefore, this paper illustrates the possibility of developing TSN as a medical product, aimed to provide directions for the clinical application and further research of TSN.

The signaling pathways and targets of natural products from traditional Chinese medicine treating gastric cancer provide new candidate therapeutic strategies

Gastric cancer (GC) is one of the severe malignancies with high incidence and mortality, especially in Eastern Asian countries. Significant advancements have been made in diagnosing and treating GC over the past few decades, resulting in tremendous improvements in patient survival. In recent years, traditional Chinese medicine (TCM) has garnered considerable attention as an alternative therapeutic approach for GC due to its multicomponent and multitarget characteristics. Consequently, natural products found in TCM have attracted researchers' attention, as growing evidence suggests that these natural products can impede GC progression by regulating various biological processes. Nevertheless, their molecular mechanisms are not systematically uncovered. Here, we review the major signaling pathways involved in GC development. Additionally, clinical GC samples were analyzed. Moreover, the anti-GC effects of natural products, their underlying mechanisms and potential targets were summarized. These summaries are intended to facilitate further relevant research, and accelerate the clinical applications of natural products in GC treatment.

Toosendanin inhibits osteoclast formation and alleviate postmenopausal osteoporosis by regulating the p38 signaling pathway

Disruption of the balance between osteoclasts and osteoblasts could lead to bone diseases including osteoporosis. It's well known that RANKL-RANK signaling plays a vital role in activating osteoclasts. Herein, we explored the therapeutic effects of toosendanin (TSN) in osteoporosis, showing that TSN attenuated RANKL-stimulated osteoclastogenesis and osteoclast-specific gene expression in vitro. Bioinformatics predicted that TSN could interfere p38 subunits and regulate the MAPK cascade, and we further verified and demonstrated that TSN significantly inhibited RANKL-induced p38 signaling through western blot. In ovariectomized mouse model, TSN effectively inhibited the formation of TRAP-positive osteoclasts and exhibited protective effect against bone loss. Altogether, these data indicate that TSN targeted p38 activation to inhibit osteoclastogenesis, suggesting the possible therapeutic use of TSN in osteoporosis in the future.

Small-molecule toosendanin reverses macrophage-mediated immunosuppression to overcome glioblastoma resistance to immunotherapy

T cell-based immunotherapy holds promise for treating solid tumors, but its therapeutic efficacy is limited by intratumoral immune suppression. This immune suppressive tumor microenvironment is largely driven by tumor-associated myeloid cells, including macrophages. Here, we report that toosendanin (TSN), a small-molecule compound, reprograms macrophages to enforce antitumor immunity in glioblastoma (GBM) in mouse models. Our functional screen of genetically probed macrophages with a chemical library identifies that TSN reverses macrophage-mediated tumor immunosuppression, leading to enhanced T cell infiltration, activation, and reduced exhaustion. Chemoproteomic and structural analyses revealed that TSN interacts with Hck and Lyn to abrogate suppressive macrophage immunity. In addition, a combination of immune checkpoint blockade and TSN therapy induced regression of syngeneic GBM tumors in mice. Furthermore, TSN treatment sensitized GBM to Egfrviii chimeric antigen receptor (CAR) T cell therapy. These findings suggest that TSN may serve as a therapeutic compound that blocks tumor immunosuppression and circumvents tumor resistance to T cell-based immunotherapy in GBM and other solid tumors that warrants further investigation.

Toosendanin reduces cisplatin resistance in ovarian cancer through modulating the miR-195/ERK/β-catenin pathway

BACKGROUND

Cisplatin (DDP) resistance is prevalent in ovarian cancer (OC) patients and contributes to the poor prognosis. Therefore, it is of great significance to develop new agent to intervene and even reverse DDP resistance in OC. Toosendanin (TSN), a triterpenoid extracted from the bark or fruits of Melia toosendan Sieb et Zucc, has been proved to possess significant antitumor activities. However, the efficacy of TSN on DDP resistance in OC has not been reported yet.

PURPOSE

The aim of this study is to investigate the effects of TSN on DDP resistance in OC and explore the molecular mechanism in vitro and in vivo.

METHODS

Human OC cell line (SKOV3) and DDP-resistant cell line (SKOV3/DDP) were used. Cell proliferation was measured by CCK-8 and colony formation assay. Annexin V/PI double staining and hoechst 33342 nuclear staining were employed to detect cell apoptosis. Transwell and wound-healing assay were used to determine the invasion and migration potential of cells respectively. Quantitative real-time PCR (qPCR) and western blotting were performed to detect the expression of molecules related to miR-195/ERK/β-catenin pathway. The effects and mechanism of TSN on DDP resistance of OC in vivo was investigated using xenograft model, TUNEL staining assay and immunohistochemistry.

RESULTS

TSN improved the DDP sensitivity of SKOV3/DDP cells in vitro and in vivo, reflected in promoting inhibition of proliferation, invasion, migration and epithelial mesenchymal transformation (EMT) as well as induction of apoptosis by DDP. TSN could modulate the miR-195/ERK/β-catenin axis by upregulating the miR-195-5p expression and then suppressing ERK/GSK3β/β-catenin pathway which were activated in SKOV3/DDP cells. Moreover, co-treatment of β-catenin pathway activator LiCl or miR-195-5p silencing partially recovered the DDP resistance which was previously repressed by TSN.

CONCLUSION

Both in vitro and in vivo data demonstrated that TSN could reduce DDP resistance in OC through regulating the miR-195/ERK/β-catenin pathway, highlighting the potential of TSN as an effective agent for favoring overcoming clinical DDP resistance in OC.

Molecular mechanisms underlying the action of carcinogens in gastric cancer with a glimpse into targeted therapy

BACKGROUND

Gastric cancer imposes a substantial global health burden despite its overall incidence decrease. A broad spectrum of inherited, environmental and infectious factors contributes to the development of gastric cancer. A profound understanding of the molecular underpinnings of gastric cancer has lagged compared to several other tumors with similar incidence and morbidity rates, owing to our limited knowledge of the role of carcinogens in this malignancy. The International Agency for Research on Cancer (IARC) has classified gastric carcinogenic agents into four groups based on scientific evidence from human and experimental animal studies. This review aims to explore the potential comprehensive molecular and biological impacts of carcinogens on gastric cancer development and their interactions and interferences with various cellular signaling pathways.

CONCLUSIONS

In this review, we highlight recent clinical trial data reported in the literature dealing with different ways to target various carcinogens in gastric cancer. Moreover, we touch upon other multidisciplinary therapeutic approaches such as surgery, adjuvant and neoadjuvant chemotherapy. Rational clinical trials focusing on identifying suitable patient populations are imperative to the success of single-agent therapeutics. Novel insights regarding signaling pathways that regulate gastric cancer can potentially improve treatment responses to targeted therapy alone or in combination with other/conventional treatments. Preventive strategies such as control of H. pylori infection through eradication or immunization as well as dietary habit and lifestyle changes may reduce the incidence of this multifactorial disease, especially in high prevalence areas. Further in-depth understanding of the molecular mechanisms involved in the role of carcinogenic agents in gastric cancer development may offer valuable information and update state-of-the-art resources for physicians and researchers to explore novel ways to combat this disease, from bench to bedside. A schematic outlining of the interaction between gastric carcinogenic agents and intracellular pathways in gastric cancer H. pylori stimulates multiple intracellular pathways, including PI3K/AKT, NF-κB, Wnt, Shh, Ras/Raf, c-MET, and JAK/STAT, leading to epithelial cell proliferation and differentiation, apoptosis, survival, motility, and inflammatory cytokine release. EBV can stimulate intracellular pathways such as the PI3K/Akt, RAS/RAF, JAK/STAT, Notch, TGF-β, and NF-κB, leading to cell survival and motility, proliferation, invasion, metastasis, and the transcription of anti-apoptotic genes and pro-inflammatory cytokines. Nicotine and alcohol can lead to angiogenesis, metastasis, survival, proliferation, pro-inflammatory, migration, and chemotactic by stimulating various intracellular signaling pathways such as PI3K/AKT, NF-κB, Ras/Raf, ROS, and JAK/STAT. Processed meat contains numerous carcinogenic compounds that affect multiple intracellular pathways such as sGC/cGMP, p38 MAPK, ERK, and PI3K/AKT, leading to anti-apoptosis, angiogenesis, metastasis, inflammatory responses, proliferation, and invasion. Lead compounds may interact with multiple signaling pathways such as PI3K/AKT, NF-κB, Ras/Raf, DNA methylation-dependent, and epigenetic-dependent, leading to tumorigenesis, carcinogenesis, malignancy, angiogenesis, DNA hypermethylation, cell survival, and cell proliferation. Stimulating signaling pathways such as PI3K/Akt, RAS/RAF, JAK/STAT, WNT, TGF-β, EGF, FGFR2, and E-cadherin through UV ionizing radiation leads to cell survival, proliferation, and immortalization in gastric cancer. The consequence of PI3K/AKT, NF-κB, Ras/Raf, ROS, JAK/STAT, and WNT signaling stimulation by the carcinogenic component of Pickled vegetables and salted fish is the Warburg effect, tumorigenesis, angiogenesis, proliferation, inflammatory response, and migration.

Screening of Plant-Derived Natural Extracts to Identify a Candidate Extract Capable of Enhancing Lipid Synthesis in Keratinocytes

BACKGROUND

Reduced lipid content in the stratum corneum is a major cause of skin-barrier dysfunction in various pathological conditions. Promoting lipid production is a potential strategy to improve skin-barrier function. Recent evidence supports the beneficial effects of adiponectin on lipid metabolism and senescence in keratinocytes.

OBJECTIVE

This study aimed to investigate whether plant extracts can enhance skin-barrier function.

METHODS

We screened fruit and herb extracts that enhance the lipid synthesis of keratinocytes via AMP-activated protein kinase (AMPK) activation and SIRT1 signaling in the adiponectin pathway. The levels of major lipid synthesis enzymes and transcription factors as well as epidermal barrier lipids involved in adiponectin-associated epidermal barrier formation were evaluated in the herbal extracts- or adiponectin-treated human epidermal keratinocyte and equivalent models. The mRNA expression of major lipid synthesis enzymes increased following treatment with Lycii Fructus , Prunus tomentosa , and Melia toosendan extracts.

RESULTS

The expression of transcription factors SIRT1, liver X receptor α, peroxisome proliferator-activated receptors (PPARs), and sterol regulatory element-binding proteins (SREBPs) were upregulated. Levels of free fatty acids, cholesterol, and ceramides were elevated. The expression of keratinocyte differentiation markers increased. In particular, among fruit extracts with a detectable effect, Melia toosendan induced the highest expression of lipid synthase.

CONCLUSION

These results indicate that Melia toosendan is a promising candidate for improving skin-barrier function.

Limonoids From the Genus Melia (Meliaceae): Phytochemistry, Synthesis, Bioactivities, Pharmacokinetics, and Toxicology

Limonoids, as the vital bioactive chemical compounds in genus Melia plants, have attracted significant attention owing to their exclusive structural characteristics and remarkable biological activity. These compounds can be usually classified into two categories, including the ring-intact group and the ring-C-seco group. Benefiting from the development of separation and analysis technology, more than 200 limonoids have been isolated and identified from this genus. There is growing evidence that limonoids from genus Melia possess diverse pharmacological activities, especially anti-cancer effects, insecticidal activities, and anti-botulism effects. Toosendanin, one of the paramount limonoids, was considered as the pivotal bioactive marker in two medicinal herbs, including Melia toosendan Sieb. et Zucc and Melia azedarach L. In particular, limonoids are found to exhibit non-negligible toxic effects, a finding which needs further research. Besides this, the lack of clinical research data seriously hinders its further development and utilization, and necessary clinical trials should be taken into consideration. In this review, we systematically summarized the phytochemical compounds and their synthesis methods, pharmacological activities, and the structure–activity relationship, pharmacokinetics, and toxicology of genus Melia-derived limonoids. We believe that this up-to-date review could provide scientific evidence for the application of limonoids as agents beneficial to health in future clinical practice.

Screening of a Small Molecule Compound Library Identifies Toosendanin as an Inhibitor Against Bunyavirus and SARS-CoV-2

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne virus causing serious infectious disease with a high case-fatality of up to 50% in severe cases. Currently, no effective drug has been approved for the treatment of SFTSV infection. Here, we performed a high-throughput screening of a natural extracts library for compounds with activities against SFTSV infection. Three hit compounds, notoginsenoside Ft1, punicalin, and toosendanin were identified for displaying high anti-SFTSV efficacy, in which, toosendanin showed the highest inhibition potency. Mechanistic investigation indicated that toosendanin inhibited SFTSV infection at the step of virus internalization. The anti-viral effect of toosendanin against SFTSV was further verified in mouse infection models, and the treatment with toosendanin significantly reduced viral load and histopathological changes in vivo. The antiviral activity of toosendanin was further expanded to another bunyavirus and the emerging SARS-CoV-2. This study revealed a broad anti-viral effect of toosendanin and indicated its potential to be developed as an anti-viral drug for clinical use.

Mechanisms involved in the anti-tumor effects of Toosendanin in glioma cells

BACKGROUND

Toosendanin (TSN) is a triterpenoid compound mainly used as an ascaris repellant. Recent studies have shown that it possesses antitumor effects in many types of tumor cells. However, the effects of TSN on glioma cells have rarely been reported.

METHODS

Different assays were performed to investigate the effects of TSN on the different glioma cell lines including U87MG and LN18. The assays included colony formation, wound healing, and transwell assays. Furthermore, Hoechst 33342 staining, flow cytometry, and western blotting analysis were performed to investigate the apoptotic activities of TSN. Finally, the results were confirmed using a xenograft tumor model that comprised of nude mice.

RESULTS

In vitro, the CCK-8 and colony formation assays showed that TSN effectively inhibited glioma cell proliferation. Moreover, the inhibitory effects on glioma cell migration and invasion were demonstrated through the wound healing and transwell assays, respectively. Hoechst 33342 staining, flow cytometry, and western blotting assays demonstrated the significant effect of TSN in the apoptosis induction of glioma cells. Furthermore, the anti-glioma effect of TSN was exerted through the inhibition of the PI3K/Akt/mTOR signaling pathways as demonstrated by western blotting analysis. In addition, the effects of TSN on glioma cell viability, apoptosis, cell cycle arrest, migration, and invasion were reversed by 740Y-P, a PI3K activator. Finally, the mouse xenograft model confirmed the suppressive effect of TSN on tumor growth in vivo.

CONCLUSION

Our results suggest that TSN is a promising chemotherapeutic drug for patients with glioma.

Toosendanin Shows Potent Efficacy Against Human Ovarian Cancer through Caspase-Dependent Mitochondrial Apoptotic Pathway

Toosendanin (TSN) is a triterpenoid extracted from the bark or fruits of Melia toosendan Sieb et Zucc, which is a traditional Chinese medicine and mainly grows in China and India. TSN has been verified to possess antitumor activities on various human cancers, whereas the effects of TSN on ovarian cancer (OC) has not been reported yet. Here, TSN was shown to significantly inhibit proliferation of SKOV3 and OVCAR3 cell lines in a dose- and time-dependent manner. Treatment of OC cells with TSN resulted in colony formation reduction, S and G2/M phase arrest, cell apoptosis, and dramatic decrease in mitochondrial membrane potential. Furthermore, TSN suppressed invasion and migration of OC cells. Research on molecular mechanism indicated that the above efficacy of TSN was associated with decreased expression of survivin, PARP-1, Bcl-2, Bcl-xl, caspase-3, caspase-9, MMP-2 and MMP-9 and increased expression of cleaved PARP-1, Bax, cleaved caspase-3 and cleaved caspase-9. Finally, in vivo results showed that TSN suppressed OC xenograft tumor growth by inducing apoptosis and regulating the related protein expression levels of SKOV3 cells in transplanted tumors. Taken together, our data provide new insights into TSN as a potentially effective reagent against human OC through caspase-dependent mitochondrial apoptotic pathway.

Potential of Bioactive Food Components against Gastric Cancer: Insights into Molecular Mechanism and Therapeutic Targets

Gastric cancer, also known as stomach cancer, is a cancer that develops from the lining of the stomach. Accumulated evidence and epidemiological studies have indicated that bioactive food components from natural products play an important role in gastric cancer prevention and treatment, although its mechanism of action has not yet been elucidated. Particularly, experimental studies have shown that natural bioactive food products display a protective effect against gastric cancer via numerous molecular mechanisms, such as suppression of cell metastasis, anti-angiogenesis, inhibition of cell proliferation, induction of apoptosis, and modulation of autophagy. Chemotherapy remains the standard treatment for advanced gastric cancer along with surgery, radiation therapy, hormone therapy, as well as immunotherapy, and its adverse side effects including neutropenia, stomatitis, mucositis, diarrhea, nausea, and emesis are well documented. However, administration of naturally occurring bioactive phytochemical food components could increase the efficacy of gastric chemotherapy and other chemotherapeutic resistance. Additionally, several studies have suggested that bioactive food components with structural stability, potential bioavailability, and powerful bioactivity are important to develop novel treatment strategies for gastric cancer management, which may minimize the adverse effects. Therefore, the purpose of this review is to summarize the potential therapeutic effects of natural bioactive food products on the prevention and treatment of gastric cancer with intensive molecular mechanisms of action, bioavailability, and safety efficacy.

Albendazole exerts antiproliferative effects on prostate cancer cells by inducing reactive oxygen species generation

Benzimidazole derivatives are used for their antihelmintic properties, but have also been reported to exert anticancer effects. In the present study, the anticancer effects of albendazole on prostate cancer cells were assessed using proliferation, clonogenic and migration assays. To investigate the anticancer mechanisms of albendazole, reactive oxygen species (ROS) levels were measured, and the expression of genes associated with oxidative stress and Wnt/β-catenin signaling was confirmed by reverse transcription-quantitative PCR and western blotting. Albendazole selectively inhibited the proliferation of the PC3, DU145, LNCaP and AT2 prostate cancer cell lines at concentrations that did not affect the proliferation of a normal prostate cell line (RWPE-1). Albendazole also inhibited the colony formation and migration of PC3 and DU145 cells, as well as inducing ROS production. Diphenyleneiodonium chloride, an inhibitor of NADPH oxidase (NOX), one of the sources of ROS, decreased basal ROS levels in the PC3 and DU145 cells, but did not reduce albendazole-associated ROS production, suggesting that ROS production following albendazole treatment was NOX-independent. The anticancer effect was decreased when albendazole-induced ROS was reduced by treatment with antioxidants (glutathione and N-acetylcysteine). Furthermore, albendazole decreased the mRNA expression of CDGSH iron sulfur domain 2, which regulates antioxidant activity against ROS, as well as the antioxidant enzymes catalase, and glutathione peroxidase 1 and 3. Albendazole also decreased the mRNA expression of catenin β1 and transcription factor 4, which regulate Wnt/β-catenin signaling and its associated targets, Twist family BHLH transcription factor 1 and BCL2. The albendazole-related decrease in the expression levels of oxidative stress-related genes and Wnt/β-catenin signaling proteins was thought to be associated with ROS production. These results suggest that the antihelmintic drug, albendazole, has inhibitory effects against prostate cancer cells in vitro. Therefore, albendazole may potentially be used as a novel anticancer agent for prostate cancer.

Participation of MicroRNAs in the Treatment of Cancer with Phytochemicals

Cancer is a global health concern and one of the main causes of disease-related death. Even with considerable progress in investigations on cancer therapy, effective anti-cancer agents and regimens have thus far been insufficient. There has been compelling evidence that natural phytochemicals and their derivatives have potent anti-cancer activities. Plant-based anti-cancer agents, such as etoposide, irinotecan, paclitaxel, and vincristine, are currently being applied in medical treatments for patients with cancer. Further, the efficacy of plenty of phytochemicals has been evaluated to discover a promising candidate for cancer therapy. For developing more effective cancer therapy, it is required to apprehend the molecular mechanism deployed by natural compounds. MicroRNAs (miRNAs) have been realized to play a pivotal role in regulating cellular signaling pathways, affecting the efficacy of therapeutic agents in cancer. This review presents a feature of phytochemicals with anti-cancer activity, focusing mainly on the relationship between phytochemicals and miRNAs, with insights into the role of miRNAs as the mediators and the regulators of anti-cancer effects of phytochemicals.

A Atractylodes lancea polysaccharide inhibits metastasis of human osteosarcoma U-2 OS cells by blocking sialyl Lewis X (sLex )/E-selectin binding

In this study, a new water and alkaline‐soluble polysaccharide (ALP), with an average molecular weight of 6.63 × 10⁴ Da, was successfully purified from the rhizomes of Atractylodes lancea. GC analysis demonstrated that ALP was a kind of glucan. The effect of the ALP on the interaction between E‐selectin and sialyl Lewis X (sLe^x) was examined in human osteosarcoma U‐2 OS cells. It was obvious that the expression of sLe^x antigen on the surface of U‐2 OS cells was visible under fluorescence microscopy. The addition of ALP (0.5, 1 and 2 mg/mL) resulted in a marked inhibition on the adhesion, migration and invasion of U‐2 OS cells to human umbilical vein endothelial cells (HUVECs), which was achieved by the decreased sLe^x expression on U‐2 OS cells. Additionally, the induction of apoptosis can be observed in U‐2 OS cells following ALP treatment using TUNEL staining and Annexin V‐FITC/PI double‐staining analysis on flow cytometry. In conclusion, these results indicated that ALP exerted anti‐metastatic activity towards osteosarcoma cells via inhibition of sLe^x/E‐selectin binding, which suggested that ALP could be a potent agent for human osteosarcoma intervention.

MicroRNAs target the Wnt/β‑catenin signaling pathway to regulate epithelial‑mesenchymal transition in cancer (Review)

Epithelial‑mesenchymal transition (EMT), during which cancer cells lose the epithelial phenotype and gain the mesenchymal phenotype, has been verified to result in tumor migration and invasion. Numerous studies have shown that dysregulation of the Wnt/β‑catenin signaling pathway gives rise to EMT, which is characterized by nuclear translocation of β‑catenin and E‑cadherin suppression. Wnt/β‑catenin signaling was confirmed to be affected by microRNAs (miRNAs), several of which are down‑ or upregulated in metastatic cancer cells, indicating their complex roles in Wnt/β‑catenin signaling. In this review, we demonstrated the targets of various miRNAs in altering Wnt/β‑catenin signaling to promote or inhibit EMT, which may elucidate the underlying mechanism of EMT regulation by miRNAs and provide evidence for potential therapeutic targets in the treatment of invasive tumors.

Structure-Based Reactivity Profiles of Reactive Metabolites with Glutathione

Therapeutic agents can be transformed into reactive metabolites under the action of various metabolic enzymes in vivo and then covalently combine with biological macromolecules (such as protein or DNA), resulting in increasing toxicity. The screening of reactive metabolites in drug discovery and development stages and monitoring of biotransformation in post-market drugs has become an important research field. Generally, reactive metabolites are electrophilic and can be captured by small nucleophiles. Glutathione (GSH) is a small peptide composed of three amino acids (i.e., glutamic acid, cysteine, and glycine). It has a thiol group which can react with electrophilic groups of reactive metabolic intermediates (such as benzoquinone, N-acetyl-p-benzoquinoneimine, and Michael acceptor) to form a stable binding conjugate. This paper aims to provide a review on structure-based reactivity profiles of reactive metabolites with GSH. Furthermore, this review also reveals the relationship between drugs' molecular structures and reactive metabolic toxicity from the perspective of metabolism, giving a reference for drug design and development.

Toosendanin induces apoptosis of MKN‑45 human gastric cancer cells partly through miR‑23a‑3p‑mediated downregulation of BCL2

Toosendanin (TSN) is a tetracyclic triterpenoid extracted from Melia toosendan Sieb, et Zucc, which primarily grows in specific areas of China. Although toosendanin (TSN) exerts antitumoral effects on various human cancer cells, its influence on gastric cancer (GC) is remains to be elucidated. MicroRNAs (miRNAs/miRs) serve crucial roles in apoptosis and proliferation of cancer cells. miR-23a-3p has been shown to be associated with human GC; however, the specific function of miR-23a-3p in GC remains unclear. Therefore, the present study aimed to elucidate the role of miR-23a-3p in the regulation of GC cell proliferation and apoptosis induced in vitro by TSN treatment. Subsequently, apoptosis-related genes expression levels were quantified by reverse transcription-quantitative PCR and western blot analysis, respectively, and the target relationship between miR-23a-3p and BCL2 was determined by luciferase reporter gene analysis. Additionally, cell proliferation and apoptosis experiments were carried out. The results indicated that TSN inhibited proliferation and induced apoptosis in MKN-45 cells. Moreover, it upregulated the expression of miR-23a-3p. B-cell lymphoma-2 (BCL2) was identified as a potential target gene of miR-23a-3p, which was demonstrated to bind to the 3′-untranslated region of BCL2 mRNA, as detected by the luciferase reporter assay. Further studies revealed that BCL2 expression was downregulated following overexpression of miR-23a-3p. In addition, the overexpression of the miR-23a-3p inhibited proliferation, induced G₁ arrest and increased apoptosis in MKN-45 cells. The results of the present study demonstrated that miR-23a-3p inhibited proliferation and induced apoptosis of GC cells, which may be attributable to its direct targeting of BCL2. These results may provide a novel insight into the apoptosis of GC cells, and may lead to investigations into the mechanisms of the effects of TSN.

Toosendanin Suppresses Glioma Progression Property and Induces Apoptosis by Regulating miR-608/Notch Axis

Background

Glioma is one the most common and aggressive primary tumors of adult central nervous system worldwide, which tends to develop dysplasia and metastasis. Recently, toosendanin (TSN) has shown pharmacological effects in several cancers. However, little is known about the underlying mechanism of the effect of TSN on glioma and its relationship between miRNA in glioma.

Methods

Cell proliferation, cell cycle, cell apoptosis and cell migration were analyzed by CCK-8 cell viability, flow cytometry, wound scratch healing, transwell and Western blotting assays, respectively, in vitro. The regulation relationships between TSN and miR-608 or between miR-608 and Notch1 (Notch2) were examined using qRT-PCR, dual-luciferase and Western blotting assays. The functional effects of TSN through regulating miR-608 and Notch1 (Notch2) were further examined using a xenograft tumor mouse model in vivo.

Results

After TSN concentration was increased from 50 nM, 100 nM to 150 nM, cell proliferation and cell cycle were gradually reduced, and the cell apoptosis rate was increased in U-138MG or U-251MG cells. Wound-healing and transwell assays results showed that cell migration was significantly inhibited in TSN treatment cells (TSN treatment, 50 nM) compared to control cells. Mechanistic studies revealed that TSN up-regulated the expression of microRNA-608 (miR-608), while down-regulated the expression of miR-608’s target, Notch1 and Notch2. Over-expression of Notch1 and Notch2 partly attenuated TSN-induced tumor suppressive function. Moreover, in vivo experiments revealed that TSN treatment led to a significant inhibition of tumor growth, suggesting that it might be a promising drug for the treatment of glioma.

Conclusion

In the present study, a novel established functional manner of TSN/miR-608/Notch1 (Notch2) axis was systematically indicated, which might provide prospective intervention ways for glioma therapy.

Toosendanin alleviates dextran sulfate sodium-induced colitis by inhibiting M1 macrophage polarization and regulating NLRP3 inflammasome and Nrf2/HO-1 signaling

Toosendanin (TSN), a triterpenoid extracted from the bark of fruit of Melia toosendan Sieb et Zucc, has been proven to have various biological activities including anti-inflammatory activity. But its effects on experimental colitis remain unreported. Herein, we investigated the role and potential mechanisms of TSN in dextran sulfate sodium (DSS) induced colitis in mice. The results showed that, TSN reduced colitis-associated disease activity index (DAI), shortened colon length, and weakened the pathological damage of the colon tissues in murine colitis models. Further studies disclosed that, TSN inhibited the secretion of proinflammatory cytokines and oxidative stress, and suppressed M1 macrophage polarization and the activation of NLR family pyrin domain containing 3 (NLRP3) inflammasome, but upregulated HO-1/Nrf2 expression in murine colitis. In addition, TSN maintained intestinal barrier by regulating zonula occludens-1 (ZO-1) and occludin expression. In conclusion, our findings demonstrated that, TSN alleviates DSS-induced experimental colitis by inhibiting M1 macrophage polarization and regulating NLRP3 inflammasome and Nrf2/HO-1 signaling, and may provide a novel Chinese patent medicine for the treatment of murine colitis.

Non-coding RNAs in regulating gastric cancer metastasis

Gastric cancer is one of the leading causes of cancer-related deaths worldwide, and mortality remains high, especially in East Asia. At present, the main method to diagnose gastric cancer is pathological biopsy. At the time of diagnosis, most patients have been diagnosed with advanced cancer and metastasis. The treatment of gastric cancer patients is mainly radical surgical resection and chemoradiotherapy, while patients with metastatic tumor have great challenges to radical surgery and are prone to drug resistance. Metastasis is an important factor affecting tumor development. In addition, evidence accumulated in the literature indicates that non-coding RNA plays a key role in tumor metastasis. This article reviews the role of ncRNAs in gastric cancer metastasis and discusses the regulatory mechanism in the development and treatment of gastric cancer.

CircDLST promotes the tumorigenesis and metastasis of gastric cancer by sponging miR-502-5p and activating the NRAS/MEK1/ERK1/2 signaling

Background

Accumulating evidence shows that, the dysregulation of circular RNAs (circRNAs) is associated with the progression of multiple malignancies. But, the underlying mechanisms by which has_circ_0032627 (circDLST) contributed to gastric cancer (GC) remain undocumented.

Methods

The expression and cellular localization of circDLST and its association with clinicopathological characteristics and prognosis in patients with GC was analysed by using fluorescence in situ hybridization. Gain- and loss-of-function experiments as well as a subcutaneous xenograft tumor model and a liver metastasis model from orthotopic implantation of GC tissues were conducted to assess the role of circDLST in GC cells. CircDLST specific binding with miR-502-5p was confirmed by dual luciferase gene report, RNA immunoprecipitation (RIP) assays and RIP-miRNA expression profiling. qRT-PCR and Western blot analysis was used to detect the effects of circDLST on miR-502-5p-mediated NRAS/MEK1/ERK1/2 signaling in GC cells.

Results

The expression levels of circDLST were dramatically elevated in GC tissues as compared with the adjacent normal tissues, and acted as an independent prognostic factor of poor survival in patients with GC. Knockdown of circDLST inhibited the cell viability, colony formation, DNA synthesis, cell invasion and liver metastasis in vitro and in vivo, whereas overexpression of circDLST had the opposite effects. Furthermore, circDLST was co-localized with miR-502-5p in the cytoplasm of GC cells, and acted as a sponge of miR-502-3p in GC cells, which abrogated the tumor promoting effects of circDLST by inactivating the NRAS/MEK1/ERK1/2 signaling in GC cells.

Conclusion

CircDLST promotes the tumorigenesis and metastasis of GC cells by sponging miR-502-5p to activate the NRAS/MEK1/ERK1/2 signaling.

Electronic supplementary material

The online version of this article (10.1186/s12943-019-1015-1) contains supplementary material, which is available to authorized users.