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1.
Chin J Nat Med ; 22(3): 265-272, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38553193

ABSTRACT

Four new sesquiterpene lactones (SLs) (1-4), along with a biosynthetically related SL (5), have been isolated from the leaves of Magnolia grandiflora. Magrandate A (1) is notable as the first C18 homogemarane type SL, featuring a unique 1,7-dioxaspiro[4.4]nonan-6-one core. Compounds 2 and 3, representing the first instances of chlorine-substituted gemarane-type SL analogs in natural products, were also identified. The structures of these isolates were elucidated through a combination of spectroscopic data analysis, electronic circular dichroism calculations, and X-ray single-crystal diffraction analysis. All isolates demonstrated anti-inflammatory activity in lipopolysaccharide-stimulated RAW264.7 cells. Notably, 3-5 showed a significant inhibitory effect on nitric oxide production, with IC50 values ranging from 0.79 to 4.73 µmol·L-1. Additionally, 4 and 5 exhibited moderate cytotoxic activities against three cancer cell lines, with IC50 values between 3.09 and 11.23 µmol·L-1.


Subject(s)
Magnolia , Sesquiterpenes , Molecular Structure , Magnolia/chemistry , Anti-Inflammatory Agents/pharmacology , Sesquiterpenes/pharmacology , Sesquiterpenes/chemistry , Lactones/pharmacology , Lactones/chemistry
2.
J Agric Food Chem ; 71(44): 16581-16592, 2023 Nov 08.
Article in English | MEDLINE | ID: mdl-37897427

ABSTRACT

Physalis angulata Linn. is an exotic Amazonian fruit that is commonly recognized as wild tomato, winter cherry, and gooseberry. While its fruit is known to contain many nutrients, such as minerals, fibers, and vitamins, few papers have investigated withanolide derivatives from its fruits. UPLC-Q-Orbitrap-MS/MS, which produces fragmentation spectra, was applied for the first time to guide the isolation of bioactive withanolide derivatives from P. angulata fruits. As a result, twenty-six withanolide derivatives, including two novel 1,10-secowithanolides (1 and 2) and a new derivative (3), were obtained. Compounds 1 and 2 are rare rearranged 1,10-secowithanolides with a tetracyclic 7/6/6/5 ring system. All structures were assigned through various spectroscopic data and quantum chemical calculations. Nine withanolide derivatives exhibited significant inhibitory effects on three tumor cell lines with IC50 values of 0.51-13.79 µM. Moreover, three new compounds (1-3) exhibited potential nitric oxide inhibitory effects in lipopolysaccharide-stimulated RAW264.7 cells (IC50: 7.51-61.8 µM). This investigation indicated that fruits of P. angulata could be applied to treat and prevent cancer and inflammatory-related diseases due to their potent active withanolide derivatives.


Subject(s)
Physalis , Withanolides , Physalis/chemistry , Structure-Activity Relationship , Withanolides/pharmacology , Withanolides/chemistry , Fruit , Tandem Mass Spectrometry , Plant Extracts/pharmacology , Plant Extracts/chemistry
3.
Chin J Nat Med ; 21(6): 443-453, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37407175

ABSTRACT

This study employed the α-glucosidase inhibitory activity model as an anti-diabetic assay and implemented a bioactivity-guided isolation strategy to identify novel natural compounds with potential therapeutic properties. Hypericum sampsoniiwas investigated, leading to the isolation of two highly modified seco-polycyclic polyprenylated acylphloroglucinols (PPAPs) (1 and 2), eight phenolic derivatives (3-10), and four terpene derivatives (11-14). The structures of compounds 1 and 2, featuring an unprecedented octahydro-2H-chromen-2-one ring system, were fully characterized using extensive spectroscopic data and quantum chemistry calculations. Six compounds (1, 5-7, 9, and 14) exhibited potential inhibitory effects against α-glucosidase, with IC50 values ranging from 0.050 ± 0.0016 to 366.70 ± 11.08 µg·mL-1. Notably, compound 5 (0.050 ± 0.0016 µg·mL-1) was identified as the most potential α-glucosidase inhibitor, with an inhibitory effect about 6900 times stronger than the positive control, acarbose (IC50 = 346.63 ± 15.65 µg·mL-1). A docking study was conducted to predict molecular interactions between two compounds (1 and 5) and α-glucosidase, and the hypothetical biosynthetic pathways of the two unprecedented seco-PPAPs were proposed.


Subject(s)
Hypericum , Molecular Structure , Hypericum/chemistry , alpha-Glucosidases , Magnetic Resonance Spectroscopy , Glycoside Hydrolase Inhibitors/pharmacology
4.
Phytomedicine ; 114: 154810, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37075623

ABSTRACT

BACKGROUND: Breast cancer is the most prevalent cancer worldwide, with high morbidity and mortality. Despite great advances in the therapeutic strategies, the survival rate in the past decades of patients with breast cancer remains unsatisfactory. Growing evidence has demonstrated that Curcumae Rhizoma, called Ezhu in Chinese, showed various pharmacological properties, including anti-bacterial, anti-oxidant, anti-inflammatory and anti-tumor activities. It has been widely used in Chinese medicine to treat many types of human cancer. PURPOSE: To comprehensively summarize and analyze the effects of active substances in Curcumae Rhizoma on breast cancer malignant phenotypes and the underlying mechanisms, as well as discuss its medicinal value and future perspectives. METHOD: We used "Curcumae Rhizoma" or the name of crude extracts and bioactive components in Curcumae Rhizoma in combination with "breast cancer" as key words. Studies focusing on their anti-breast cancer activities and mechanisms of action were extracted from Pubmed, Web of Science and CNKI databases up to October 2022. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 guideline was followed. RESULTS: Crude extracts and 7 main bioactive phytochemicals (curcumol, ß-elemene, furanodiene, furanodienone, germacrone, curdione and curcumin) isolated from Curcumae Rhizoma have shown many anti-breast cancer pharmacological properties, including inhibiting cell proliferation, migration, invasion and stemness, reversing chemoresistance, and inducing cell apoptosis, cycle arrest and ferroptosis. The mechanisms of action were involved in regulating MAPK, PI3K/AKT and NF-κB signaling pathways. In vivo and clinical studies demonstrated that these compounds exhibited high anti-tumor efficacy and safety against breast cancer. CONCLUSION: These findings provide strong evidence that Curcumae Rhizoma acts as a rich source of phytochemicals and has robust anti-breast cancer properties.


Subject(s)
Breast Neoplasms , Drugs, Chinese Herbal , Humans , Female , Drugs, Chinese Herbal/pharmacology , Phosphatidylinositol 3-Kinases , Curcuma/chemistry , Rhizome/chemistry , Signal Transduction
5.
Org Biomol Chem ; 21(1): 140-146, 2022 12 21.
Article in English | MEDLINE | ID: mdl-36458939

ABSTRACT

Hyperpatone A (1), a highly oxidated polycyclic polyprenylated acylphloroglucinol (PPAP), along with a biosynthesized related PPAP (2) was isolated from Hypericum patulum under the guidance of LC-MS investigation. Architecturally, compound 1 represents the first PPAP with an unprecedented 8/6/5/6/5 pentacyclic skeleton and an intramolecular peroxy bridge, which might be derived from the [3.3.1]-type bicyclic polyprenylated acylphloroglucinol via the critical Baeyer-Villiger oxidation, decarboxylation, and intramolecular cyclization. The structures were established by extensive spectroscopic analysis, ACD software calculation, and quantum chemical computations. A plausible biogenetic pathway of 1 and 2 was also proposed. Importantly, both compounds exhibited moderate cytotoxic activities against the HEL cell line with the IC50 values ranging from 10.2 to 19.2 µM. Moreover, compound 1 showed an inhibitory effect on NO production in lipopolysaccharide-stimulated RAW264.7 cells at a lower concentration of 5 or 1 µM.


Subject(s)
Hypericum , Molecular Structure , Hypericum/chemistry , Phloroglucinol/chemistry , Skeleton
6.
J Org Chem ; 87(17): 11309-11318, 2022 09 02.
Article in English | MEDLINE | ID: mdl-35981284

ABSTRACT

Six novel Maillard reaction products (MRPs) (1-6) were isolated from the processed Thermopsis lanceolata R. Br. seed extract, along with one biogenetically related intermediate (7). Compounds 1-4 possessed three rare dimerization patterns constructed by cytisine, whereas compounds 5 and 6 represented the first example of the addition products of cytisine and 5,6-dihydroxy-4-hexanolide. Their structures were elucidated by comprehensive spectroscopic data analysis and quantum chemistry calculations including GIAO 13C{1H} NMR and ECD calculation, combined with single-crystal X-ray diffraction analysis. Biologically, compound 3 displayed significant anti-tobacco mosaic virus activity compared with the positive control ningnanmycin.


Subject(s)
Tobacco Mosaic Virus , Antiviral Agents/chemistry , Glycation End Products, Advanced , Plant Extracts/chemistry
7.
ACS Omega ; 7(32): 28003-28015, 2022 Aug 16.
Article in English | MEDLINE | ID: mdl-35990498

ABSTRACT

In the theory of traditional Chinese medicine (TCM), "liver-qi" stagnation and heat-induced toxicity represent the main etiologies of breast cancer. Recently, several TCMs with heat-clearing and detoxification efficacy have shown inhibitory effects on breast cancer. Jin'gan capsules (JGCs), initially approved to treat colds in China, are a heat-clearing and detoxification TCM formula. However, the anticancer activity of JGCs against breast cancer and its underlying mechanisms remain unclear. First, we assessed the antiproliferative activity of JGCs in breast cancer cell lines and evaluated their effects on cell apoptosis and the cell cycle by flow cytometry. Furthermore, we identified the potential bioactive components of JGCs and their corresponding target genes and constructed a bioactive compound-target interaction network by ultra-performance liquid chromatography-high-resolution tandem mass spectrometry (UPLC-HR-MS/MS) and network pharmacology analysis. Finally, the underlying mechanism was investigated through gene function enrichment analysis and experimental validation. We found that JGCs significantly inhibited breast cancer cell growth with IC50 values of 0.56 ± 0.03, 0.16 ± 0.03, and 0.94 ± 0.09 mg/mL for MDA-MB-231, MDA-MB-468, and MCF-7, respectively. In addition, JGC treatment dramatically induced apoptosis and S phase cell cycle arrest in breast cancer cells. Western blot analysis confirmed that JGCs could regulate the protein levels of apoptosis- and cell cycle-related genes. Utilizing UPLC-HR-MS/MS analysis and network pharmacology, we identified 7 potential bioactive ingredients in JGCs and 116 antibreast cancer targets. Functional enrichment analysis indicated that the antitumor effects of JGCs were strongly associated with apoptosis and the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway. Western blot analysis validated that JGC treatment markedly decreased the expression levels of p-JAK2, p-STAT3, and STAT3. Our findings suggest that JGCs suppress breast cancer cell proliferation and induce cell cycle arrest and apoptosis partly by inhibiting the JAK2/STAT3 signaling pathway, highlighting JGCs as a potential therapeutic candidate against breast cancer.

8.
Org Lett ; 24(32): 5967-5971, 2022 08 19.
Article in English | MEDLINE | ID: mdl-35925684

ABSTRACT

Hypersampones A-C (1-3), three unprecedented nor-polycyclic polyprenylated acylphloroglucinols (PPAPs), were isolated from Hypericum sampsonii. These compounds represent the first nor-PPAPs with an unexpected tetracyclic 6/5/5/6 ring system. Their structures were assigned through the analysis of detailed spectroscopic data, X-ray crystallography, and electronic circular dichroism calculations. Compound 1 significantly inhibited the accumulation of lipid in an oleic acid-treated HepG2 cell model by suppressing the protein expression of FAS and ACACA at 5 µM.


Subject(s)
Hypericum , Crystallography, X-Ray , Hep G2 Cells , Humans , Hypericum/chemistry , Lipids , Molecular Structure , Phloroglucinol/chemistry , Phloroglucinol/pharmacology
9.
Front Pharmacol ; 13: 809551, 2022.
Article in English | MEDLINE | ID: mdl-35721186

ABSTRACT

Chronic myeloid leukemia (CML) accounts for a major cause of death in adult leukemia patients due to mutations or other reasons for dysfunction in the ABL proto-oncogene. The ubiquitous BCR-ABL expression stimulates CML by activating CDK1 and cyclin B1, promoting pro-apoptotic, and inhibiting antiapoptotic marker expression along with regulations in RAS pathway activation. Thus, inhibitors of cyclins and the RAS pathway by ERK are of great interest in antileukemic treatments. Mikanolide is a sesquiterpene dilactone isolated from several Asteraceae family Mikania sp. plants. Sesquiterpene dilactone is a traditional medicine for treating ailments, such as flu, cardiovascular diseases, bacterial infections, and other blood disorders. It is used as a cytotoxic agent as well. The need of the hour is potent chemotherapeutic agents with cytotoxic effects inhibition of proliferation and activation of apoptotic machinery. Recently, ERK inhibitors are used in clinics as anticancer agents. Thus, in this study, we synthesized 22-mikanolide derivatives that elucidated to be potent antileukemic agents in vitro. However, a bioactive mikanolide derivative, 3g, was found with potent antileukemic activity, through the Ras/Raf/MEK/ERK pathway. It can arrest the cell cycle by inhibiting phosphorylation of CDC25C, triggering apoptosis, and promoting DNA and mitochondrial damage, thus suggesting it as a potential chemotherapeutic agent for leukemia patients.

10.
Front Pharmacol ; 13: 863707, 2022.
Article in English | MEDLINE | ID: mdl-35770098

ABSTRACT

Polygoni Cuspidati Rhizoma et Radix, the dry roots and stems of Reynoutria japonica Houtt (called Huzhang, HZ in Chinese), is a traditional and popular chinese medicinal herb for thousands of years. As a widely used ethnomedicine in Asia including China, Japan, and Korea, HZ can invigorate the blood, cool heat, and resolve toxicity, which is commonly used in the treatment of favus, jaundice, scald, and constipation. However, HZ is now considered an invasive plant in the United States and many European countries. Therefore, in order to take advantage of HZ and solve the problem of biological invasion, scholars around the world have carried out abundant research studies on HZ. Until now, about 110 compounds have been isolated and identified from HZ, in which anthraquinones, stilbenes, and flavonoids would be the main bioactive ingredients for its pharmacological properties, such as microcirculation improvement, myocardial protective effects, endocrine regulation, anti-atherosclerotic activity, anti-oxidant activity, anti-tumor activity, anti-viral activity, and treatment of skin inflammation, burns, and scalds. HZ has a variety of active ingredients and broad pharmacological activities. It is widely used in health products, cosmetics, and even animal husbandry feed and has no obvious toxicity. Efforts should be made to develop more products such as effective drugs, health care products, cosmetics, and agricultural and animal husbandry products to benefit mankind.

11.
Phytochemistry ; 193: 112970, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34689099

ABSTRACT

Hypericum monogynum L. (Hypericaceae) has been used as a folk Chinese medicine for the treatment of inflammatory related diseases. Cyclooxygenase-2 (COX-2) is a crucial target for the development of agents to treat inflammation. To search for anti-inflammatory compounds from traditional Chinese medicines, a chemical constituent study along with COX-2 inhibitory activity analysis was performed for this plant. In this study, sixteen chemical monomers, including three undescribed oxidative degradation polycyclic polyprenylated acylphloroglucinols (PPAPs, hypemoins C-E), two undescribed PPAPs (hypemoins A and B), and 11 known compounds, were identified from the flowers of H. monogynum. Their structures were characterized by HRESIMS, NMR techniques, ECD, and single crystal X-ray diffraction. Four flavonoid derivatives showed remarkable COX-2 inhibitory activities, with IC50 values ranging from 0.220 ± 0.006 to 1.655 ± 0.098 µM. Among these compounds, the possible recognition mechanism between quercetin 3-(6″-O-caffeoyl)-ß-3-D-galactoside and COX-2 was predicted by molecular docking analysis. Moreover, the multidrug resistance reversal activities for the selected compounds were evaluated.


Subject(s)
Hypericum , Cyclooxygenase 2 , Flowers , Molecular Docking Simulation , Molecular Structure , Phloroglucinol/pharmacology
12.
Zhongguo Zhong Yao Za Zhi ; 46(17): 4522-4530, 2021 Sep.
Article in Chinese | MEDLINE | ID: mdl-34581058

ABSTRACT

Magnoliae Officinalis Cortex(Houpo) can treat peptic ulcer disease(PUD), the mechanism of which remains unclear. In this study, network pharmacology and molecular docking were employed to predict the mechanism of Houpo in the treatment of PUD. Through literature review and TCMSP screening, 15 main active ingredients were obtained. The SwissTargetPrediction database was used to predict the potential targets of the ingredients, and Therapeutic Target Database(TTD), DrugBank, and Human Phenotype Ontology(HPO) to screen the disease-related targets. A total of 49 potential targets were obtained by the intersection of active ingre-dients-related targets and disease-related targets. Cytoscape 3.6.1 was employed to construct the protein-protein interaction network for the targets with high confidence(score>0.700) screened out by STRING. The DAVID database was used for GO and KEGG pathway enrichment of potential targets. GO enrichment analysis showed that the treatment mechanism was mostly related to nuclear receptor activity, ligand-activated transcription factor activity, and G protein-coupled acetylcholine receptor activity. KEGG enrichment analysis found that Houpo could regulate material metabolism, endocrine system, p53 signaling pathway, and PPAR signaling pathway. Molecu-lar docking verified that all 15 ingredients had good binding activities with key targets(CHRM1, CHRM2, FABP1, mTOR, and STAT3). The results mean that Houpo can treat PUD by participating in cell metabolism, inhibiting inflammatory cytokines, and regulating cell proliferation and apoptosis.


Subject(s)
Drugs, Chinese Herbal , Peptic Ulcer , Humans , Molecular Docking Simulation , Protein Interaction Maps , Receptor, Muscarinic M1 , Signal Transduction
13.
Fitoterapia ; 151: 104876, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33675885

ABSTRACT

Six rocaglaol derivatives were isolated from Dysoxylum gotadhora, and those compounds showed good cytotoxic activity with IC50 values ranging from 10 to 350 ng/mL against five different cancer cells. Obviously, further total synthesis of rocaglaol derivatives for medical chemistry study is of great significance. Then, twenty six rocaglaol derivatives including 25 new compounds were designed, synthesized, and evaluated for their cytotoxic activities against three human cancer cell lines: human colon cancer cells (HCT116), colorectal cancer stem cells (P6C), and human red leukocyte leukemia cells (HEL), using MTT assay. Most of derivatives showed good cytotoxic activities, with the lowest IC50 being 3.2 nM for HEL cells, which was 169 times stronger than that of the positive control (doxorubicin). Further mechanism study indicated that 11k could significantly suppress MAPK pathway in HCT116 cells, which may responsible for induction of apoptosis and cell cycle arrest.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Apoptosis/drug effects , Benzofurans/pharmacology , MAP Kinase Signaling System/drug effects , Meliaceae/chemistry , Antineoplastic Agents, Phytogenic/isolation & purification , Benzofurans/isolation & purification , Cell Cycle Checkpoints/drug effects , Cell Line, Tumor , China , Drug Screening Assays, Antitumor , HCT116 Cells , Humans , Molecular Structure , Phytochemicals/isolation & purification , Phytochemicals/pharmacology
14.
Biomed Pharmacother ; 118: 109265, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31545282

ABSTRACT

Kaempferol-3-O-rhamnoside (KOR) has multiple potency involved in anti-cancer, anti-inflammatory and antibacterial actions. However, the potential roles of KOR and the analogues isolated from the leaves of Cyclocarya paliurus in anti-erythroleukemia remain unclear. In the present study, KOR and the two analogues (Kaempferol-3-O-(4″-O-acetyl-a-L-rhamnopyranoside) (KLR) and (kaempferol-3-O-α-L-(4″-E-p-coumaroyl) rhamnoside) (KCR) were isolated from leaves of Cyclocarya paliurus. Cell viability assay showed that KCR exerted an excellent anti-erythroleukemia activity. We observed that KCR not only significantly increased the percentage of G2 phase and apoptotic cells compared with control group, but also induced megakaryocytic differentiation in HEL and K562 cells by flow cytometry, indicating that KCR might inhibit cell proliferation through inducing differentiation-mediated apoptosis and cell cycle arrest. Mechanism investigation revealed that KCR treatment obviously increased phosphorylation levels of PKCδ and ERK1/2 as well as GATA1 expression. Taken together, these findings demonstrate that KCR induces megakaryocytic differentiation and suppresses leukemogenesis at least partly through activation of PKCδ/ERK1/2 signaling pathway in erythroleukemia cells. KCR may also serve as a promising natural compound for human erythroleukemia treatment.


Subject(s)
Carcinogenesis/pathology , Cell Differentiation/drug effects , Leukemia/pathology , MAP Kinase Signaling System/drug effects , Megakaryocytes/pathology , Protein Kinase C-delta/metabolism , Small Molecule Libraries/pharmacology , Apoptosis/drug effects , Carcinogenesis/drug effects , Cell Cycle Checkpoints/drug effects , Glycosides/chemistry , Glycosides/pharmacology , Glycosides/therapeutic use , Humans , Inhibitory Concentration 50 , K562 Cells , Kaempferols/chemistry , Kaempferols/pharmacology , Kaempferols/therapeutic use , Leukemia/drug therapy , Megakaryocytes/drug effects , Models, Biological , Plant Extracts/pharmacology , Plant Extracts/therapeutic use , Plant Leaves/chemistry , Small Molecule Libraries/chemistry
15.
Biomed Pharmacother ; 112: 108603, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30784914

ABSTRACT

C-21 steroids displayed the activities of immunosuppressive, anti-inflammatory and anti-virus effects by the reports. However, its antitumor effects and molecular mechanism remain unclear. We previously isolated and identified a C-21 steroidal glycoside (BW18) from the root of Cynanchum atratum Bunge. This study was aimed to assess anti-leukemia activity and its underlying mechanism in K562 cells. MTT assay results showed that BW18 inhibited cell viability and proliferation of K562 cells. We also found that BW18 could induce S phase cell cycle arrest and apoptosis. Furthermore, our results demonstrated that BW18 regulated the expression of apoptosis and cell cycle related proteins. Mechanism investigation revealed that the anti-leukemia activity of BW18 may be mediated through MAPK pathway. These findings indicate that BW18 possesses an excellent anti-leukemia activity via regulating MAPK pathway leading to S phase cell cycle arrest and apoptosis, which suggested BW18 could be as a potential alternative therapeutic agent for CML patients.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Glycosides/pharmacology , MAP Kinase Signaling System/drug effects , Phytosterols/pharmacology , S Phase/drug effects , Antineoplastic Agents/isolation & purification , Antineoplastic Agents/therapeutic use , Apoptosis/physiology , Cell Cycle Checkpoints/drug effects , Cell Cycle Checkpoints/physiology , Dose-Response Relationship, Drug , Drugs, Chinese Herbal/isolation & purification , Drugs, Chinese Herbal/pharmacology , Drugs, Chinese Herbal/therapeutic use , Glycosides/isolation & purification , Glycosides/therapeutic use , Humans , K562 Cells , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism , MAP Kinase Signaling System/physiology , Phytosterols/isolation & purification , Phytosterols/therapeutic use , S Phase/physiology
16.
Cell Death Dis ; 10(2): 117, 2019 02 11.
Article in English | MEDLINE | ID: mdl-30741932

ABSTRACT

The ETS transcription factor Fli-1 controls the expression of genes involved in hematopoiesis including cell proliferation, survival, and differentiation. Dysregulation of Fli-1 induces hematopoietic and solid tumors, rendering it an important target for therapeutic intervention. Through high content screens of a library of chemicals isolated from medicinal plants in China for inhibitors of a Fli-1 transcriptional reporter cells, we hereby report the identification of diterpenoid-like compounds that strongly inhibit Fli-1 transcriptional activity. These agents suppressed the growth of erythroleukemic cells by inducing apoptosis and differentiation. They also inhibited survival and proliferation of B-cell leukemic cell lines as well as primary B-cell lymphocytic leukemia (B-CLL) isolated from 7 patients. Moreover, these inhibitors blocked leukemogenesis in a mouse model of erythroleukemia, in which Fli-1 is the driver of tumor initiation. Computational docking analysis revealed that the diterpenoid-like compounds bind with high affinity to nucleotide residues in a pocket near the major groove within the DNA-binding sites of Fli-1. Functional inhibition of Fli-1 by these compounds triggered its further downregulation through miR-145, whose promoter is normally repressed by Fli-1. These results uncover the importance of Fli-1 in leukemogenesis, a Fli-1-miR145 autoregulatory loop and new anti-Fli-1 diterpenoid agents for the treatment of diverse hematological malignancies overexpressing this transcription factor.


Subject(s)
DNA/metabolism , Diterpenes/chemistry , Proto-Oncogene Protein c-fli-1/metabolism , Animals , Apoptosis/drug effects , Binding Sites , Carcinogenesis/drug effects , Cell Line, Tumor , DNA/chemistry , Diterpenes/pharmacology , Diterpenes/therapeutic use , Gene Expression Regulation, Neoplastic/drug effects , Humans , Kaplan-Meier Estimate , Leukemia/drug therapy , Leukemia/mortality , Leukemia/pathology , Mice , Mice, Inbred BALB C , MicroRNAs/genetics , MicroRNAs/metabolism , Molecular Docking Simulation , Promoter Regions, Genetic , Protein Structure, Tertiary , Proto-Oncogene Protein c-fli-1/antagonists & inhibitors , Proto-Oncogene Protein c-fli-1/genetics , RNA Interference , RNA, Small Interfering/metabolism , RNA, Small Interfering/therapeutic use
17.
FEBS J ; 285(24): 4631-4645, 2018 12.
Article in English | MEDLINE | ID: mdl-30387554

ABSTRACT

E26 transformation-specific (ETS) gene family contains a common DNA-binding domain, the ETS domain, responsible for sequence-specific DNA recognition on target promoters. The Fli-1 oncogene, a member of ETS gene family, plays a critical role in hematopoiesis and is overexpressed in diverse hematological malignancies. This ETS transcription factor regulates genes controlling several hallmarks of cancer and thus represents an excellent target for cancer therapy. By screening compounds isolated from the medicinal plant Dysoxylum binectariferum in China, we identified two chemically related flavagline-like compounds including 4'-demethoxy-3',4'-methylenedioxyrocaglaol and rocaglaol that strongly inhibited Fli-1 transactivation ability. These compounds altered expression of Fli-1 target genes including GATA1, EKLF, SHIP1, and BCL2. Consequently, the flavagline-like compounds suppressed proliferation, induced apoptosis, and promoted erythroid differentiation of leukemic cells in culture. These compounds also suppressed erythroleukemogenesis in vivo in a Fli-1-driven mouse model. Mechanistically, the compounds blocked c-Raf-MEK-MAPK/ERK signaling, reduced phosphorylation of eukaryotic translation initiation factor 4E (eIF4E), and inhibited Fli-1 protein synthesis. Consistent with its high expression in myelomas, B-cell lymphoma, and B chronic lymphocytic leukemia (B-CLL), pharmacological inhibition of Fli-1 by the flavagline-like compounds or genetic knock-down via shRNA significantly hindered proliferation of corresponding cell lines and patients' samples. These results uncover a critical role of Fli-1 in growth and survival of various hematological malignancies and point to flavagline-like agents as lead compounds for the development of anti-Fli-1 drugs to treat leukemias/lymphomas overexpressing Fli-1.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Benzofurans/pharmacology , Leukemia/drug therapy , Plant Extracts/pharmacology , Proto-Oncogene Protein c-fli-1/antagonists & inhibitors , Signal Transduction/drug effects , Animals , Antineoplastic Agents, Phytogenic/chemistry , Apoptosis , Benzofurans/chemistry , Cell Cycle , Cell Proliferation , High-Throughput Screening Assays , Humans , Leukemia/metabolism , Leukemia/pathology , Mice , Plant Extracts/chemistry , Plants, Medicinal/chemistry , Tumor Cells, Cultured
18.
Oncotarget ; 8(10): 16728-16743, 2017 Mar 07.
Article in English | MEDLINE | ID: mdl-28052010

ABSTRACT

The ETS-related transcription factor Fli-1 affects many developmental programs including erythroid and megakaryocytic differentiation, and is frequently de-regulated in cancer. Fli-1 was initially isolated following retrovirus insertional mutagenesis screens for leukemic initiator genes, and accordingly, inhibition of this transcription factor can suppress leukemia through induction of erythroid differentiation. To search for modulators of Fli-1, we hereby performed repurposing drug screens with compounds isolated from Chinese medicinal plants. We identified agents that can transcriptionally activate or inhibit a Fli-1 reporter. Remarkably, agents that increased Fli-1 transcriptional activity conferred a strong anti-cancer activity upon Fli-1-expressing leukemic cells in culture. As opposed to drugs that suppress Fli1 activity and lead to erythroid differentiation, growth suppression by these new Fli-1 transactivating compounds involved erythroid to megakaryocytic conversion (EMC). The identified compounds are structurally related to diterpene family of small molecules, which are known agonists of protein kinase C (PKC). In accordance, these PKC agonists (PKCAs) induced PKC phosphorylation leading to activation of the mitogen-activated protein kinase (MAPK) pathway, increased cell attachment and EMC, whereas pharmacological inhibition of PKC or MAPK diminished the effect of our PKCAs. Moreover, in a mouse model of leukemia initiated by Fli-1 activation, the PKCA compounds exhibited strong anti-cancer activity, which was accompanied by increased presence of CD41/CD61 positive megakaryocytic cells in leukemic spleens. Thus, PKC agonists offer a novel approach to combat Fli-1-induced leukemia, and possibly other cancers,by inducing EMC in part through over-activation of the PKC-MAPK-Fli-1 pathway.


Subject(s)
Diterpenes/pharmacology , Leukemia, Erythroblastic, Acute/drug therapy , Microfilament Proteins/metabolism , Protein Kinase C/metabolism , Proto-Oncogene Protein c-fli-1/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Small Molecule Libraries/pharmacology , Animals , Cell Differentiation/drug effects , Erythroid Precursor Cells/drug effects , Erythroid Precursor Cells/pathology , Humans , K562 Cells , Leukemia, Erythroblastic, Acute/enzymology , Leukemia, Erythroblastic, Acute/genetics , Leukemia, Erythroblastic, Acute/pathology , MAP Kinase Signaling System , Megakaryocytes/drug effects , Megakaryocytes/pathology , Mice , NIH 3T3 Cells , Trans-Activators
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