Gambogic acid induces mitochondria-dependent apoptosis by modulation of Bcl-2 and Bax in mantle cell lymphoma JeKo-1 cells

Objective： To study the mechanisms in gambogic acid （GA） -induced JeKo-1 human Mantle Cell Lymphoma cell apoptosis in vitro. Methods： The proliferation of GA-treated JeKo-1 cells was measured by CCK-8 assay and Ki-67 immunocytochemical detection. Apopt0sis, cell cycle and mitochondrial membrane potential were measured by flow cytometric analysis. Caspase-3, -8 and -9 were detected by colorimetric assay. Bcl-2 and Bax were analyzed by Western blotting. Results： GA inhibited cell growth in a time- and dose- dependent manner. GA induces apoptosis in JeKo- 1 cells but not in normal bone marrow cells, which was involved in reducing the membrane potential of mitochondria, activating caspases-3, -8 and -9 and decreasing the ratio of Bd-2 and Bax without cell cycle arresting. Conclusions： GA induced apoptosis in human MCL JeKo-1 cells by regulating Bcl-2/Bax and activating caspase-3, -8 and -9 via mitochondrial pathway without affecting cell cycle.

Effects of Gambogic Acid on the Regulation of Nucleoporin Nup88 in U937 Cells

In order to investigate the anti-leukemia effects of gambogic acid （GA） and its relation to the regulation of nucleoporin Nup88 in U937 cells in vitro, the inhibitory effect of GA on the growth of U937 cells was examined by using MTT assay. Apoptosis was detected by Annexin-V FITC/PI double-labeled cytometry. Cell cycle regulation was studied by propidium iodide method. Both flow cytometry （FCM） and RT-PCR were employed to assess the expression of Nup88, and the localization of Nup88 was determined by confocal microscopy. The results indicated that GA had strong inhibitory effect on cell proliferation and apoptosis induction activity in U937 cells in vitro in a time-and dose-dependent manner. The 24-h IC50 value was （1.019±0.134） mg/L. Moreover, GA induced arrest of U937 cells in G0/G1 phase. Over-expression of Nup88 was found in U937 cells, whereas GA could significantly down-regulate both the protein and mRNA levels of Nup88. Nup88 was diffusely distributed between nucleus and cytoplasm and was located at the cytoplasmic side of nuclear rim, and occasionally in cytoplasm. It is suggested that GA exerts its anti-leukemia effects by regulating the expression and distribution of nucleoporin Nup88. It promises to be new agent for the treatment of acute leukemia.

Effect of Gambogic Acid on the Regulation of hERG Channel in K562 Cells in vitro

Overexpression of human ether-h-go-go （eag） related gene （bERG） has been found in a broad range of human leukemia cell lines and primary human leukemia. The block of hERG protein might be a potential therapeutic strategy for leukemia. Gambogic acid （GA） has recently exhibited marked anti-tumor potency on solid tumors of various derivations. Here, we investigated the anti-leukemia effects of GA and its relation to the regulation of hERG in K562 leukemia cells in vitro. K562 cells were treated with various concentrations of GA （0.125-8.0 μmol/L） for 0-72 h. MTT assay was used to evaluate the inhibition effect of GA on the growth of K562 cells. Cell apoptosis was measured through both Annexin-V FITC/PI double-labeled cytometry and transmission electron microscopy. Cell cycle regulation was studied by a propidium iodide method. RT-PCR and Western blot were applied to detect the expression level of hERG in K562 cells. GA presented striking growth inhibition and apoptosis induction potency on K562 ceils in vitro in a time- and dose-dependent manner. The IC50 value of GA for 24 h was 2.637±0.208 μmol/L. Moreover, GA induced K562 cells arrested in G0/G1 phase, accordingly, cells in S phase decreased gradually, and no obvious changes were found in G2/M phase cells. Under the transmission electron microscopy, apoptotic bodies containing nuclear fragments were found in GA-treated K562 cells. After treatment with GA of 2.0 μmol/L for 24 h, the percentage of apoptotic cells was increased from 4.09% to 18.47% （P〈0.01）. Overexpression of hERG channel was found in K562 cells, while GA could down-regulate it at both protein and mRNA levels （P〈0.01）. It was concluded that GA exhibited its anti-leukemia effects partially through down-regulating the expression level of hERG channel in K562 cells, suggesting that GA may be a potential agent against leukemia with a mechanism of blocking hERG channel.

Synthesis and antitumor activities of structure-related small molecular compounds of gambogic acid

Through simplifying the complicated skeleton of the natural product gambogic acid, two series derivatives of chromone and xanthone were synthesized and examined for their antitumor activities against several cancer cells in vitro by MTT method. The results showed that appropriate introduction of prenyl group to the small molecular compounds could elevate their antitumor activities. The structure–activities relationship of synthesized compounds certified that the bridgecore in gambogic acid was very important for keeping its antitumor activities.

Effects of Gambogic Acid on Regulation of Steroid Receptor Coactivator-3 in Lung Adenocarcinoma A549 Cells

Objective： To investigate the effects of gambogic acid （GA） on the proliferation and apoptosis of Human lung adenocarcinoma A549 cells in vitro, as well as the regulation of steroid receptor coactivator-3 （SRC-3） to explore the relationship between them. Methods： The effect of GA on the growth of A549 cells was studied by MTT assay. Apoptosis was detected through Hoechst 33258 staining. RT-PCR and Western blot technologies were applied to assess the expression of SRC-3, whereas, the localization of SRC-3 was determined by using confocal microscopy method. Results： GA presented striking proliferation inhibition potency on A549 cells in vitro in a time- and dose-dependent manner, with the IC50 value for 24 h was 3.17±0.13 μmol/L. Hoechst 33258 staining showed that GA could induce apoptosis in A549 cells. Over-expression of SRC-3 was found in A549 cells, whereas the mRNA and protein expression levels of SRC-3 were significantly downregulated in A549 cells induced by GA in a dose-dependent manner. The disposition of SRC-3 was situated mainly at the nuclear. Conclusion： GA may exert its strong anti-leukemia effects through the regulation of the expression of SRC-3. It may be a new target for the therapy of lung cancer.

Enhanced anti-cancer effect of gambogic acid by gold nanorod-based delivery

OBJECTIVE Nanotechnology provides a novel strategy for the delivery of anticancer drugs.In this study,titanium dioxide coated gold nanorod(GNR/TiO_2) nanostructures were used as the drug carrier for gambogic acid in order to improve its anticancer effect.METHODS Biocompatibility and cellular uptake of GNR/TiO_2 nanostructures were studied in human glioblastoma U-87 MG cells.Cell viability was evaluated by ATP assay and calcein AM staining.Lyso Sensor Green DND-189 and Hoechst 33342 were used to analyze the intracellular location of GNR/TiO_2 nanostructures.The in vitro anti-cancer effect of gambogic acid loaded nanoparticles was compared with free drug.RESULTS The results showed that GNR/TiO_2 nanostructures are biocompatible,and they are localized at the intracellular acidic compartments of endosomes and lysosomes.The intracellular drug content delivered via GNR/TiO_2 nanostructures was 6 fold higher than the free form,thus dramatically enhancing the anticancer effect of gambogic acid.Furthermore,mild photothermal therapy also showed synergistic effect with the drug.CONCLUSION Our study suggested that GNR/TiO_2 nanostructures can be considered as a promising anticancer drug carrier.

Multifunctional nano-herb based on tumor microenvironment for enhanced tumor therapy of gambogic acid

Multifunctional drug delivery systems(DDSs)have shown great prospects in overcoming the heterogeneous barrier of delivery drugs to the complex tumor microenvironment(TME).In this study,multifunctional AS/Ge-pNAB microgels with dual-active targeting,triple environment responsiveness,and fluorescence imaging capability were prepared through a straightforward procedure.This was aimed to improve the antitumor therapeutic application of gambogic acid(GA)based on the biological characteristics of TME.The microgels have a uniform double-layer structure with aptamer in the outer layer which helps in recognizing receptors on the tumor cells.The GA loaded nano-herb exhibited environment-responsive drug release profiles under acidic pH,reductant and high temperature.The nano-herb significantly improved the accumulation of GA in tumor sites through the synergistic combination of the enhanced permeability and retention effect and dual-ligand mediated internalization.Then,it accelerated intracellular drug release and killed tumor cells.Therefore,the nano-herb had specific therapeutic effects on the tumor in vitro and in vivo as they remarkably inhibited tumor growth while depicting optimal biosafety and lower levels of off-target toxicity.Overall,these findings demonstrate the great potential of the multifunctional AS/Ge-pNAB microgels for precisely targeted GA delivery and open a new avenue for the facile preparation of multifunctional DDSs.

Erythrocyte membrane encapsulated gambogic acid nanoparticles as a therapeutic for hepatocellular carcinoma

Gambogic acid(GA)is a potential clinical anticancer drug that can exert antitumor effects via various molecular mechanisms.Notwithstanding,GA’s low water solubility,poor stability,short half-life,and unavoidable toxic side effects have significantly hampered its clinical application.Erythrocyte membranecoated nanoparticles(RBCM-NPs)improve drug’s physicochemical properties,biocompatibility,and pharmacokinetic behaviors,allowing for long-term drug circulation and passive targeting.In this study,a novel biomimetic drug delivery system(DDS)against hepatocellular carcinoma was prepared by covering RBCM on GPP-NPs(GA-loaded m PEG-PLA NPs)to develop the RBC@GPP-NPs.In comparison to RBCM-free nanoparticles and free GA,RBC@GPP-NPs improved the drug’s water solubility,stability,safety,and antitumor activity in vivo.We expect that this bionic nanoparticle composite can expand the clinical applicability of GA and provide a feasible solution for the research and development of GA’s nano-formulation.

An open-labeled, randomized, multicenter phase Ⅱa study of gambogic acid injection for advanced malignant tumors

Background Gambogic acid is a pure active compound isolated from the traditional Chinese medicinal plant gamboge （Garcinia morella Desv.）. Based on the preliminary results of a phase I study, this phase Ila study compared the efficacy and safety of different dosage schedules of gambogic acid in patients with advanced malignant tumors. Methods Patients with advanced or metastases cancer who had not received any effective routine conventional treatment or who had failed to respond to the existing conventional treatment were randomly assigned to receive either 45 mg/m2 gambogic acid intravenously from Days 1 to 5 of a 2-week cycle （Group A）, or 45 mg/m2 every other day for a total of five times during a 2-week cycle （Group B）. The primary endpoint was objective response rate （ORR）. Results Twenty-one patients assigned to Group A and 26 to Group B were included in the final analysis. The ORRs were 14.3% in Group A and 0% in Group B. It was not possible to analyze the significant difference because one of the values was zero. The disease control rates （DCRs） were 76.2% in Group A and 61.5% in Group B （P=0.0456）. The observed adverse reactions were mostly Grades I and II, and occurred in most patients after administration of the trial drug. There was no significant difference in the incidence of adverse reactions between the two arms. Conclusions The preliminary results of this phase Ila exploratory study suggest that gambogic acid has a favorable safety profile when administered at 45 mg/m2. The DCR was greater in patients receiving gambogic acid on Days 1-5 of a 2-week cycle, but the incidence of adverse reactions was similar irrespective of the administration schedule.

Synthesis and Anti-tumor Evaluation of Novel C-37 Modified Derivatives of Gambogic Acid

Gambogic acid （GA, 1）, the most prominent representative of Garcinia natural products, has been reported to be a promising anti-tumor agent. In order to further explore the structure-activity relationship of GA and discover novel GA derivatives as anti-tumor agents, 17 novel C-37 modified derivatives of GA were synthesized and evaluated for their in vitro anti-tumor activities against A549, HCT-116, BGC-823, HepG2 and MCF-7 cancer cell lines. Among them, 11 compounds were found to be more potent than GA against some cancer cell lines. Notably, com- pound 8 was almost 5--10 folds more active than GA against A549 and BGC-823 cell lines with the IC50 values of 0.12 μmol·L^-1 and 0.57 μmol·L^-1, respectively. Chemical modification at C-37 position of GA by introducing of hydrophilic amines could lead to increased activity and improved drug-like properties. These findings will enhance our understanding of the structure-activity relationship （SAR） of GA and lead to the discovery of novel GA derivatives as potential anti-tumor agents.

Gambogic Acid Induces Cell Apoptosis and Inhibits MAPK Pathway in PTEN^(-/-)/p53^(-/-) Prostate Cancer Cells In Vitro and Ex Vivo

Objective： To investigate the effect of gambogic acid（GA） on the growth and cell death of castrate resistant prostate cancer（PC） with phosphate and tension homology（PTEN） and p53 genes deleted in vitro and ex vivo, and elucidate the underlying possible molecular mechanisms. Methods： PTEN^（-/-）/p53^（-/-）PC cells and Los Angeles prostate cancer-4（LAPC-4） cells were treated with GA for 24 h and 48 h, then cell viability was determined by cell proliferation assay. PTEN^（-/-）/p53^（-/-）PC cells organoids number was calculated under GA treatment for 1 week. In addition, cell titer glo assay was performed to analyze 3 dimensional cell viability of patients derived xenografts（PDX） 170.2 organoids. Flow cytometry was used to detect apoptotic cells treated with GA. And confocal image was performed to detect the apoptotic mitochondrial morphological changes. Apoptotic cell death related protein levels were measured through Western blot（WB） in GA treated cells and organoids. The expression levels of mitogen-activated protein kinases（MAPKs） pathway related ribonucleic acid（RNAs） and proteins were analyzed by reverse transcription polymerase chain reaction（RT-PCR） and WB, respectively. Results： The treatment of GA significantly reduced cell viability of PTEN^（-/-）/p53^（-/-）PC cells and LAPC-4 in a time-and concentration-dependent manner. In organoids, GA showed strong inhibition towards organoids＇ numbers and diameters and continuously led to a complete organoids inhibition with GA 150 nmol/L. Ex vivo results validated that GA 1 μmol/L inhibited 44.6% PDX170.2 organoids growth. As for mechanism, flow cytometry detected continuously increased apoptotic portion under GA treatment from 1.98% to 11.78%（6 h） and 29.94%（8 h, P〈0.05）. In addition, mitochondrial fragmentation emerged in GA treated cells indicated the mitochondrial apoptotic pathway might be involved. Furthermore, WB detected caspases-3,-9 activation and light chain（LC）-3 conversion with GA treatment. WB revealed decreased activity of MAPK pathway and down-regulation of downstream c-fos oncogene RNA level was detected by RT-PCR before undergoing apoptosis（P〈0.05）. Conclusion： GA was a potent anti-tumor compound as for PTEN-/-/p53-/-PC, which contributed to cell apoptosis via inhibition of the MAPK pathway and c-fos.

Synthesis and Anti-tumor Evaluation of B-ring Modified Caged Xanthone Analogues of Gambogic Acid

Gambogic acid （GA, 1）, the most prominent member of Garcinia natural products, has been reported to be a promising anti-tumor agent. Previous studies have suggested that the planar B ring and the unique 4-oxa-tricyclo- [4.3.1.03.7]dec-2-one caged motif were essential for anti-tumor activity. To further explore the structure-activity relationship （SAR） of caged Garcinia xanthones, two new series of B-ring modified caged GA analogues 13a-13e and 15a-lge were synthesized utilizing a Claisen/Diel-Alder cascade reaction. Subsequently, these compounds were evaluated for their in vitro antitumor activities against A549, MCF-7, SMMC-7721 and BGC-823 cancer cell lines by MTT assay. Among them, 13b-13e exhibited micromolar inhibition against several cancer cell lines, being approximately 2-4 fold less potent in comparison to GA. SAR analysis revealed that the peripheral gem-dimethyl groups are essential for maintaining antitumor activity and substituent group on C1 position of B-ring has a significant effect on potency, while modifications at C-2, C-3 and C-4 positions are relatively tolerated. These findings will enhance our understanding of the SAR of Garcinia xanthones and lead to the development of simplified analogues as potential anti-tumor agents.

Gold nanorods for gambogicacid intracellular delivery

OBJECTIVE To improve the anticancer drug gambogic acid’s effect by using titanium dioxide coated gold nanorods(GNR/Ti O2)as a drug carrier.METHODS Biocompatibility and cellular uptake of GNR/Ti O2was studied in human glioblastoma U-87 MG cells.Cel viability was evaluated by ATP assay and calcein AM staining.Lyso SensorTMGreen DND-189 and Hoechst 33342 were used to analyze the intracellular location of GNR/Ti O2.The in vitro anticancer effect of gambogic acid loaded nanoparticles was compared with free drug.RESULTS The results showed that GNR/Ti O2is biocompatible,andthey are localized at the intracellular acidic compartments of endosomes and lysosomes.The intracellular drug content delivered via GNR/Ti O2was 6 fold higher than the free form,thus dramatically enhancing the anticancer effect of gambogic acid.Furthermore,mild photothermal therapy also showed synergistic effect with the drug.CONCLUSION Our study suggested that GNR/Ti O2is a promising anticancer drug carrier。

N-gamboyl Gemcitabine Inhibits Tumor Cells Proliferation and Migration

Gambogic acid(GA) is a natural substance with a good antitumor effect, but it is too lipophilic to be metabolized and excreted, thus accumulating in the body. Gemcitabine(GEM), one of the first-line antitumor drugs, has high hydrophilicity, which greatly shortens its half-life in vivo. We previously reported a compound named N-gamboyl gemcitabine(GAG), derived from the condensation of GEM and GA, whose hydrophilicity is better than GA and stability is better than GEM. Here, the antitumor performance of GAG was investigated for the first time by using several common tumor cell lines as tumor models. The results of in vitro study showed that GAG significantly inhibited the proliferation and migration of the tumor cells. The IC50 values of GAG for the tumor cells were lower than those of GEM and GA. The present study suggests that GAG has a promising potential to be developed into a broad-spectrum antitumor drug.

Gold nanostructures for anticancer drug delivery

OBJECTIVE Nanotechnology provides a novel strategy for the delivery of anticancer drugs.METHODS Titanium dioxide coated gold nanostructures(Au/TiO2)was used as the drug carrier for the natural anticancer drug gambogic acid in order to improve its anticancer effect.Biocompatibility and cellular uptake of Au/TiO2 was studied in human glio⁃blastoma U-87 MG cells.Cell viability was evaluated by ATP assay and calcein AM staining.LysoSensor Green DND-189 and Hoechst 33342 were used to analyze the intracellular location of Au/TiO2.The anticancer effect of gambogic acid loaded nanoparticles was compared with free drug.RESULTS Au/TiO2 was biocompatible,and they were localized at the intracellular acidic compartments of endosomes and lysosomes.The intracellular drug content delivered via Au/TiO2 was 6-fold higher than the free form,thus dramatically enhancing the anticancer effect of gambogic acid.Furthermore,mild photothermal therapy also showed synergistic effect with the drug.CONCLUSION Au/TiO2 is a promising anticancer drug carrier.

Drug-induced hierarchical self-assembly of poly(amino acid)for efficient intracellular drug delivery

As a potent anticancer drug,gambogic acid(GA)suffers from its poor water solubility and low chemical stability and shows a limited clinical outcome.To address this problem,we report here a simple and effective strategy to immobilize and deliver GA using a reducible diblock poly(amino acid)as a model.The electrostatic interaction between GA and polymer enables a high drug loading content up to 53.6%.Moreover,the drug complexation induces a micelle-to-vesicle transformation,combined with a conformation tra nsition from random coil to a-helix.The hierarchically assembled drug nanocomplexes can serve as a smart carrier for efficient cell internalization and triggered release of multiple drugs under intracellular acidic and reductive conditions,resulting in a synergistic antitumor efficacy in vitro.This work provides a new insight into the drug-carrier interaction and a facile nanoplatform for drug delivery applications.

纳米共价有机框架材料用于低温抗肿瘤生长和肺转移

光热疗法(PTT)在肿瘤治疗中有着广阔的应用前景.然而,由于激光诱导的非特异性加热与热扩散现象的存在,高温热(>50℃)在破坏肿瘤的同时可能导致肿瘤附近正常器官被灼伤,给患者带来癌症复发和转移的风险.因此,在低温加热下(≤45℃)有效破坏肿瘤对光学癌症治疗方法的未来临床转化具有重要价值.此外,由于肿瘤的异质性和复杂性,使得单模态PTT的治疗效果不佳,需要发展联合抗肿瘤治疗策略.基于此,我们采用逐步合成的方法,依次通过键合缺陷功能化、客体包封和表面修饰步骤,开发了一种高效的多模式纳米治疗剂GA@PCOF@PDA.该纳米制剂可在低温条件下实现光热/化疗/光动力联合治疗,进而有效地抑制肿瘤的生长和转移.该研究表明,我们可以通过共价有机框架(COF)纳米平台的多功能集成化,实现在单一纳米平台上的多模式肿瘤治疗,进而提高治疗效果.

Synthesis and biological evaluation of glyco-GA compounds as anticancer agents

A series of novel glyco-gambogic acid（GA） compounds were synthesized and evaluated for their in vitro anti-proliferative activity against human hepatocellular carcinoma（HCC） cells.All compounds showed much better aqueous solubility（0.92- 1.89 mg/mL） than GA（0.013 mg/mL）,and displayed potent inhibition on HCC cells（IC_（50）：0.21-12.23μmol/L） and little affects on non-tumor liver cells（IC_（50）：42.56-86.43μmol/L）,suggesting that glyco-GA compounds selectively inhibit HCC proliferation,and may be promising candidates for further intensive study.

微观结构调控优化高熵非晶合金磁热性能

第二代高熵合金(非等原子比)具备超越传统合金和第一代等原子比单相高熵合金性能限制的优异性能.对于磁热高熵合金,非等原子比(Gd_(36)Tb_(20)Co_(20)Al_(24))100−xFex纤维的居里温度最高达108 K,这克服了含稀土高熵合金低温(即普遍工作温区在60 K以下)的限制.x=2和3合金含有微量纳米晶,这使得合金具有宽化的居里温度分布.本文使用电流退火技术,通过对微观结构调控进一步优化x=3纤维的磁热性能.电流退火使纤维非晶基体沉淀析出纳米晶,并造成两相间成分的差异.缩放过程中使用两个参考温度,克服多相特征所造成的缩放磁热曲线的困难.两相成分差异随着电流密度的增加而增大,在一定限度内,成分差异扩大纤维工作温区,同时使相对制冷能力提升至许多传统磁热合金(无论是单非晶相还是多相(非晶和纳米晶))的2倍以上.相比于其他含稀土高熵非晶合金,本项工作显示出在温度限制(60 K)之上较好的磁热性能.这揭示了除适当的成分设计外,微观结构调控是优化高熵合金磁热性能的可行方法.