gambogic-acid and Stomach-Neoplasms

Gambogic acid (GA) has been observed to effectively impede the progression of numerous types of cancers. In this study, we investigated the effects of miR-1275 and Secreted Protein Acidic and Cysteine Rich (SPARC) on GA in gastric cancer (GC). miR-1275 and SPARC expression were determined in GC cell lines and tissues using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The correlation between miR-1275 and SPARC expression was ascertained using Pearson's correlation coefficient. Cell proliferation was assessed using the cell counting kit-8 (CCK-8) assay. The Transwell assay was conducted to examine cell migration. A dual-luciferase reporter assay was used to verify the regulatory relationship between miR-1275 and SPARC. The levels of SPARC, Bcl-2, and Bax proteins were estimated using western blotting. To verify the effects of GA on the growth of GC cells in vivo, a tumorigenesis experiment was performed in nude mice. GA suppressed GC cell viability and migration, facilitated apoptosis, and inhibited tumor growth in vivo and in vitro. Low levels of miR-1275 been observed in GC cell lines and tissues. GA-treated GC cells manifested high miR-1275 levels. In functional experiments, miR-1275 enhanced the influence of GA on cell apoptosis, migration, and proliferation. Furthermore, GA treatment suppressed SPARC upregulation in GC cell lines and tissues. Pearson's correlation coefficient revealed that miR-1275 expression negatively correlated with SPARC expression. Mechanistically, miR-1275 promoted growth inhibition in GA-treated GC cells by targeting SPARC. Our study indicates that miR-1275 enhances the suppressive effect of GA on GC progression by inhibiting SPARC expression. Through this study, we contribute to the knowledge of a new mechanism by which GA suppresses GC progression.

Topics: Animals; Apoptosis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Gene Expression Regulation, Neoplastic; Mice; Mice, Nude; MicroRNAs; Stomach Neoplasms

Gambogic acid has demonstrated inhibitory effects on the growth of various cancer cell types, such as breast cancer, pancreatic cancer, prostate cancer, lung cancer, and osteosarcoma. This study aims to investigate the antiproliferative activity of Gambogic acid on SNU-16 cells derived from gastric signet ring cell carcinoma and elucidate the underlying mechanisms. The cytotoxic effect of gambogic acid was evaluated in SNU-16 cells by treating them with different concentrations of the compound, and the XTT cell viability assay was employed to assess cell viability. ELISA was used to measure bax, BCL-2, caspase 3, PARP, and 8-oxo-dG levels. Additionally, immunofluorescence staining was applied to assess 8-oxo-dG and LC3β levels in SNU-16 cells. It was observed that gambogic acid exerted a dose-dependent and statistically significant antiproliferative effect on SNU-16 cells. The IC

Topics: 8-Hydroxy-2'-Deoxyguanosine; bcl-2-Associated X Protein; Carcinoma, Signet Ring Cell; Caspase 3; Humans; Male; Poly(ADP-ribose) Polymerase Inhibitors; Stomach Neoplasms

Gambogic acid (GA) is a natural xanthonoid secreted by

Topics: Cell Proliferation; Humans; Necroptosis; Stomach Neoplasms; Xanthones

Gastric cancer (GC) represents the fifth most human malignant disease and the third-most common cause of cancer-related death. Gambogic acid (GA) is a natural compound with a polyprenylated xanthone structure and possesses remarkable antitumor activity in a variety of cancer cells. However, the mechanism underlying the inhibitory effect of GA in GC is far from being completely understood. The goal of the present study is to investigate whether potential microRNAs are involved in antitumor effect of GA toward GC and to elucidate the possible mechanisms. We identified that miR-26a-5p was significantly increased by GA in GC cell lines and xenograft tumor. Downregulation of miR-26a-5p not only prevented GA-induced inhibition on GC cell growth, but also suppressed GA-induced apoptosis of GC cells. Informatics assay predicted that Wnt5a was regulated by miR-26a-5p and GA-induced downregulation of Wnt5a was prevented by anti-miR-26a-5p. Reporter gene assay showed that miR-26a-5p could negatively regulate Wnt5a through direct binding with 3'-UTR messenger RNA of Wnt5a. Thus, upregulation of Wnt5a exhibited the same action tendency for GA-induced GC cell growth and apoptosis as observed by downregulation of miR-26a-5p. In conclusion, these results indicated that the inhibitory effect of GA on GC was mediated by the upregulation of miR-26a-5p and downregulation of Wnt5a. Our study provided new clues for the potential therapeutic effect of GA against GC and highlighted the importance of miR-26a-5p/Wnt5a pathway in the regulation of GC development.

Topics: Animals; Cell Line, Tumor; Female; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; MicroRNAs; Neoplasm Proteins; RNA, Neoplasm; Stomach Neoplasms; Wnt Signaling Pathway; Wnt-5a Protein; Xanthones

Gambogic acid (GA) is proved to have anti-tumor effects on gastric cancer. Due to poor solubility, non-specific biological distribution, toxicity to normal tissues and short half-life, it is hard to be applied into the clinic. To overcome these issues, we developed a thermosensitive and injectable hydrogel composed of hydroxypropyl cellulose, silk fibroin and glycerol, with short gelling time, good compatibility and sustained release, and demonstrated that the hydrogel packaged with gambogic acid nanoparticles (GA-NPs) and tumor-penetrating peptide iRGD could improve the anti-tumor activity.. The Gelling time and micropore size of the hydrogels were regulated through different concentrations of glycerol. Controlled release characteristics of the hydrogels were evaluated with a real-time near-infrared fluorescence imaging system. Location of nanoparticles from different carriers was traced by confocal laser scanning microscopy. The in vivo antitumor activity of the hydrogels packaging GA-NPs and iRGD was evaluated by investigating tumor volume and tumor size.. The thermo-sensitive properties of hydrogels were characterized by 3-4 min, 37°C, when glycerol concentration was 20%. The hydrogels physically packaged with GA-NPs and iRGD showed higher fluorescence intensity than other groups. The in vivo study indicated that the co-administration of GA-NPs and iRGD by hydrogels had higher antitumor activity than the GA-loaded hydrogels and free GA combining with iRGD. Free GA group showed few antitumor effects. Compared with the control group, the body weight in other groups had no obvious change, and the count of leukocytes and hemoglobin was slightly decreased.. The hydrogel constructed iRGD and GA-NPs exerted an effective anti-tumor effect possibly due to retention effect, local administration and continuous sustained release of iRGD promoting the penetration of nanoparticles into a deep part of tumors. The delivery system showed little systemic toxicity and would provide a promising strategy to improve anti-gastric cancer efficacy.

Topics: Animals; Antineoplastic Agents; Bombyx; Cell Line, Tumor; Fibroins; Glycerol; Humans; Hydrogels; Hypromellose Derivatives; Male; Mice, Inbred BALB C; Mice, Nude; Nanoparticles; Oligopeptides; Porosity; Stomach Neoplasms; Temperature; Tissue Distribution; Xanthones

Poor water solubility and side effects hampered the clinical application of gambogic acid (GA) in cancer therapy. Accordingly, GA-loaded polyethylene glycol-poly(ɛ-caprolactone) (PEG-PCL) nanoparticles (GA-NPs) were developed and administered peritumorally to evaluate their antitumor activity. The particle size, polydispersity index, encapsulation efficiency and loading capacity of GA-NPs were 143.78 ± 0.054 nm, 0.179 ± 0.004, 81.3 ± 2.5% and 14.8 ± 0.6%, respectively. In addition, GA-NPs showed excellent stability, good biocompatibility and sustained release profile. Endocytosis studies in vitro demonstrated that the GA-NPs were effectively taken up by tumor cells in a time-dependent manner. In vivo real-time imaging showed that the nanoparticles effectively accumulated within the tumor tissue after peritumoral administration. The cytotoxicity study revealed that the GA-NPs effectively inhibited the proliferation of gastric cancer cells. In vivo antitumor therapy with peritumoral injection of GA-NPs exhibited superior antitumor activity compared with free GA. Moreover, no toxicity was detected in any treatment group. Histological studies confirmed a lower cell density and a higher number of apoptotic cells in the GA-NPs group compared with the free GA group. Furthermore, the expression level of the cysteine proteases 3 precursor (pro-caspase3), a crucial component of cellular apoptotic pathways, was efficiently reduced in mice treated with GA-NPs. In conclusion, the GA-NPs system provided an efficient drug delivery platform for chemotherapy.

Topics: Animals; Antineoplastic Agents; Caproates; Cell Line; Drug Carriers; Drug Delivery Systems; Humans; Lactones; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Nanoparticles; Particle Size; Polyethylene Glycols; Polymers; Stomach Neoplasms; Xanthones

Gambogic acid (GA), the main active component of gamboge, is well known for its marked antitumor effect in vitro and in vivo. The aim of this study was to assess the natural interaction between GA and chemotherapeutic agents, 5-fluorouracil (5-FU), oxaliplatin (Oxa), and docetaxel (Doc), which are widely used in gastric cancer treatment. This study also investigated the effect of GA on cell apoptosis and drug-associated gene expression for further mechanism research. Synergistic interaction on human gastric cancer BGC-823 cells and MKN-28 cells was evaluated using the combination index (CI) method. The double staining method with Annexin-V-FITC and PI was employed to distinguish the apoptotic cells from others. Expression of drug-associated genes, that is, thymidylate synthase (TS), excision repair cross-complementing (ERCC1), BRCA1, tau, and β-tubulin III, was measured by real-time quantitative RT-PCR. This study found that GA had a synergistic effect on the cytotoxity of chemotherapeutic agents against both cell lines. The combination of GA and chemotherapeutic agents could also induce apoptosis in a synergistic manner. The mRNA levels of TS, ERCC1, BRCA1, tau, and β-tubulin III were suppressed at 0.009, 0.075, 0.140, 0.267, and 0.624-fold, respectively, when cells were exposed to GA at the concentration of 0.25 μM. These data suggest that GA has a promising role in enhancing the efficacy of 5-FU, Oxa, and Doc in the treatment of gastric cancer. The potential mechanism would be their synergistic effects on apoptosis induction and the downregulation of chemotherapeutic agent-associated genes.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Line, Tumor; Docetaxel; Drug Synergism; Fluorouracil; Gene Expression; Humans; Organoplatinum Compounds; Oxaliplatin; Stomach Neoplasms; Taxoids; Xanthones

Gambogic acid has a marked anti-tumor effect for gastric and colorectal cancers in vitro and in vivo. However, recent investigations on gambogic acid have focused mainly on mono-drug therapy, and its potential role in cancer therapy has not been comprehensively illustrated. This study aimed to assess the interaction between gambogic acid and docetaxel on human gastrointestinal cancer cells and to investigate the mechanism of gambogic acid plus docetaxel treatment-induced apoptotic cell death.. MTT assay was used to determine IC(50) values in BGC-823, MKN-28, LOVO and SW-116 cells after gambogic acid and docetaxel administration. Median effect analysis was applied for determination of synergism and antagonism. Synergistic interaction between gambogic acid and docetaxel was evaluated using the combination index (CI) method. Furthermore, cellular apoptosis was analyzed by Annexin-V and propidium iodide (PI) double staining. Additionally, mRNA expression of drug-associated genes, i.e., β-tublin III and tau, and the apoptosis-related gene survivin, were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR).. Gambogic acid provided a synergistic effect on the cytotoxicity induced by docetaxel in all four cell lines. The combined application of gambogic acid and docetaxel enhanced apoptosis in gastrointestinal cancer cells. Moreover, gambogic acid markedly decreased the mRNA expression of docetaxel-related genes, including β-tubulin III, tau and survivin, in BGC-823 cells.. Gambogic acid plus docetaxel produced a synergistic anti-tumor effect in gastrointestinal cancer cells, suggesting that the drug combination may offer a novel treatment option for patients with gastric and colorectal cancers.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Line, Tumor; Cell Proliferation; Colorectal Neoplasms; Docetaxel; Drug Synergism; Herb-Drug Interactions; Humans; Inhibitor of Apoptosis Proteins; Inhibitory Concentration 50; Phytotherapy; Plant Extracts; RNA, Messenger; Stomach Neoplasms; Survivin; tau Proteins; Taxoids; Tubulin; Xanthones

The design of novel targeted or combination therapies may improve treatment options for gastric cancer. In this study, we determined the inhibitory effects of 5-fluorouracil (5-FU) combined with gambogic acid (GA) on BGC-823 human gastric carcinoma cells in vitro and in vivo and investigated the underlying mechanisms. 5-FU combined with GA inhibited the viability of BGC-823 human gastric cells in a concentration-dependent manner. The pro-apoptotic activity of the two-drug combination was much stronger than single. Furthermore, the results showed GA could regulate the metabolic enzymes of 5-FU. GA decreased the mRNA levels of thymidine synthetase (TS) and dihydropyrimidine dehydrogenase (DPD), while increased the mRNA level of orotate phosphoribosyltransferase (OPRT). Moreover, combined treatment caused significantly growth inhibition of human tumor xenografts in vivo. Taken together, our data showed that GA attenuated 5-FU-induced apoptosis by modulating metabolic enzymes of 5-FU and the antigastric cancer effect of two drugs combination was much stronger than that of GA or 5-FU alone.

Topics: Animals; Annexin A5; Antimetabolites, Antineoplastic; Antineoplastic Agents, Phytogenic; Apoptosis Regulatory Proteins; Blotting, Western; Cell Line, Tumor; Cell Proliferation; Cell Survival; Drug Synergism; Female; Fluorouracil; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stomach Neoplasms; Xanthones

We previously reported that gambogic acid (GA), a natural product, was an effective telomerase inhibitor by repressing hTERT promoter. In this study, posttranscriptional regulation of the telomerase hTERT by GA was investigated in BGC-823 human gastric carcinoma cells. The telomerase activity was detected by PCR-TRAP assay. RT-PCR assay and Western blot were performed to examine the repression of telomerase hTERT and c-Myc after GA or c-Myc-specific siRNA treatment. The results indicated that GA repressed telomerase activity and hTERT transcriptional activity via down-regulation of c-Myc expression in BGC-823 human gastric carcinoma cells. We further observed that hTERT transcriptional activity was not completely blocked by c-Myc-specific siRNA, suggesting that additional factors are involved in the repression of telomerase activity. The results of Western blot and immunoprecipitation assay revealed that GA inhibits the phosphorylation of Akt. The further results also confirmed that celecoxib, an inhibitor of Akt phosphorylation, could significantly repressed telomerase activity alone and enhance the repression of telomerase activity combined with GA. These data suggested that GA inhibits the posttranslational modification of hTERT by inhibiting the phosphorylation of Akt. Collectively, we suggest that GA represses telomerase activity not only by repressing hTERT transcriptional activity via c-Myc but also by posttranslational modification of hTERT via Akt.

Topics: Celecoxib; Cell Line, Tumor; Genes, myc; Humans; Oncogene Protein v-akt; Pyrazoles; RNA Processing, Post-Transcriptional; Stomach Neoplasms; Sulfonamides; Telomerase; Transfection; Xanthones

Chemoresistance is a major obstacle to successful cancer chemotherapy. In this study, we examined the ability of gambogic acid (GA) to reverse docetaxel resistance in BGC-823/Doc gastric cancer cells.. The cytotoxic and apoptotic effect of drugs were evaluated by MTT assay and double staining with both Annexin-V-FITC and PI. Cell cycle analysis was determined by PI-stained flow cytometry. Expression of survivin and bcl-2 were evaluated by real-time quantitative RT-PCR.. Treatment of BGC-823/Doc cells with gambogic acid at concentrations of 0.05 microM, 0.1 microM, and 0.2 microM, led to a dramatic increase in docetaxel-induced cytotoxicity without any cytotoxicity by itself. In parallel, gambogic acid treatment caused an increase in apoptotic cell death by docetaxel. Cell cycle analysis indicated that gambogic acid treatment potentiated docetaxel-induced G2/M arrest. Analysis of apoptotic associated gene revealed that gambogic acid singly or in combination with docetaxel significantly downregulate the mRNA expression of survivin, while with no effect on bcl-2.. Our results describe the potential role of gambogic acid to reverse docetaxel resistance though downregulation of survivin, which may make it an attractive new agent for the chemosensitization of cancer cells.

Topics: Apoptosis; Cell Cycle; Cell Line, Tumor; Docetaxel; Drug Resistance, Neoplasm; Humans; Inhibitor of Apoptosis Proteins; Microtubule-Associated Proteins; Neoplasm Proteins; Stomach Neoplasms; Survivin; Taxoids; Xanthones

Molecular mechanisms of cell-cycle arrest caused by gambogic acid (GA), a natural product isolated from the gamboge resin of Garcinia hanburryi tree, have been investigated using BGC-823 human gastric carcinoma cells as a model. Based on our 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazoliumbromide (MTT) assay and flow cytometric analysis, treatment of BGC-823 cells with growth suppressive concentrations of GA caused an irreversible arrest in the G(2)/M phase of the cell cycle. Western blot analysis demonstrated that GA-induced cell-cycle arrest in BGC-823 cells was associated with a significant decrease in CDC2/p34 synthesis, which led to the accumulation of phosphorylated-Tyr(15) (inactive) form of CDC2/p34. Real-time PCR, western blot and kinase activity assays revealed that GA-induced reduction of CDC2/p34 expression was mediated through the inhibition of cyclin-dependent kinase (CDK)-activating kinase (CDK7/cyclin H) activity. In addition, GA-treated cells were shown to have a low level of CDK7 kinase-phosphorylated-Thr(161) CDC2/p34 (active). Taken together, our results suggested that the inhibited proliferation of GA-treated BGC-823 cells was associated with the decreased production of CDK7 mRNA and protein, which in turn, resulted in the reduction of CDK7 kinase activity. The reduced CDK7 kinase activity is responsible for the inactivation of CDC2/p34 kinase and the irreversible G(2)/M phase cell-cycle arrest of human gastric carcinoma BGC-823 cells.

Topics: CDC2 Protein Kinase; Cell Division; Cell Line, Tumor; Cyclin B; Cyclin B1; Cyclin-Dependent Kinase-Activating Kinase; Cyclin-Dependent Kinases; Dose-Response Relationship, Drug; G2 Phase; Humans; Kinetics; Phosphorylation; Stomach Neoplasms; Xanthones

To investigate the effects and potential mechanisms of gambogic acid (GA), a naturally occurring anticancer agent, on the expression and regulation of telomerase in human gastric carcinoma cells.. GA-induced inhibition of cell proliferation was evaluated by the commonly employed MTT assay on two human gastric carcinoma cell lines, MGC-803 and SGC-7901. Telomerase activity and hTERT mRNA expression were determined by telomeric repeat amplication protocol-polymerase chain reaction and reverse transcription-polymerase chain reaction, respectively. The hTERT promoter activity was measured by luciferase assay. The expression of c-MYC, an apoptotic gene that modulates the expression of hTERT promoter, was quantified by Western blotting.. The proliferation of human gastric carcinoma cell lines, MGC-803 and SGC-7901, was significantly inhibited with GA treatment. Both telomerase activity and hTERT mRNA expression were notably decreased in cells treated with GA. The activity of hTERT promoter and the expression of c-MYC were also remarkably decreased in GA-treated cells.. This study demonstrated that GA treatment of human gastric carcinoma cell lines, MGC-803 and SGC-7901, significantly reduced the expression of c-MYC in a time- and concentration-dependent manner accompanied with the down-regulation of the hTERT transcription and the ultimate reduction in telomerase activity. Our results indicate that the hTERT is a target of c-MYC activity and identify a feasible mechanism of GA's potent anticancer activity.

Topics: Cell Line, Tumor; DNA-Binding Proteins; Down-Regulation; Enzyme-Linked Immunosorbent Assay; Humans; Peptide Fragments; RNA, Messenger; Stomach Neoplasms; Telomerase; Transcription Factors; Xanthones

To investigate the anticancer effect of a traditional Chinese medicine gambogic acid (GA) in human gastric cancer line BGC-823 and further study the mechanism of apoptosis induction of GA.. Low differential human gastric cancer line BGC-823 were treated with GA at different doses and different times, the inhibitory rates were detected by MTT assay. Apoptosis induced by GA in BGC-823 cells was observed by Annexin-V/PI doubling staining flow cytometry assay. And T/C (%) was chosen to detect the inhibition of GA on human gastric adenocarcinoma BGC-823 nude mice xenografts. Apoptosis on nude mice xenografts was observed by Annexin-V/PI doubling staining flow cytometry assay and DNA fragmentation assay. To further determine the molecular mechanism of apoptosis induced by GA, the changes on the expression of bcl-2 and bax genes were detected by RT-PCR.. After incubation with GA, low differential human gastric cancer line BGC-823 was dramatically inhibited in a dose-dependent manner. After these cells was exposed to GA for 24, 48 and 72 h, the IC(50) value were 1.02+/-0.05, 1.41+/-0.20 and 1.14+/-0.19 micromol/L, respectively. Apoptosis in BGC-823 cells induced by GA was observed by Annexin-V/PI doubling staining flow cytometry assay. The apoptotic population of BGC-823 cells was about 12.96% and 24.58%, respectively, when cells were incubated with 1.2 micromol/L GA for 48 and 72 h. T/C (%) of human gastric carcinoma adenocarcinoma BGC-823 nude mice xenografts was 44.3, when the nude mice were treated with GA (8 mg/kg). Meanwhile, apoptosis induced by GA was observed in human gastric carcinoma adenocarcinoma BGC-823 nude mice xenografts. The increase of bax gene and the decrease of bc1-2 gene expressions were found by RT-PCR.. The inhibition of GA on human gastric cancer line BGC-823 was confirmed. This effect connects with the inducing apoptosis in BGC-823 cells and the molecular mechanism might be related to the reduction of expression of apoptosis-regulated gene bcl-2, and the improvement of the expression of apoptosis-regulated gene bax. The result was also confirmed in vivo.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Humans; Medicine, Chinese Traditional; Mice; Mice, Inbred BALB C; Mice, Nude; Stomach Neoplasms; Xanthones; Xenograft Model Antitumor Assays

The selective induction of apoptosis of gambogic acid (GA) on MGC-803 cells and its probable molecular mechanism were studied. GA greatly inhibited (24, 48, 72 h) the growth of MGC-803 cells (by MTT); the IC(50) value was 0.96 microg/ml at 48 h. Meanwhile, no influence was observed on body weight, number of WBC (white blood cells) in blood or karyote in marrow of rats after GA was injected intravenously. We conclude that GA does not affect normal cells, but that it can induce apoptosis in tumor cells selectively and there were marked morphological changes. A great quantity of apoptotic cells and increasing G(2)/M phase cells were observed by flow cytometry, and a significant percentage of early apoptotic cells were observed by Annexin-V/PI double staining assay. The increase of bax gene and the decrease of bc1-2 gene expressions were detected by immunohistochemistry. Activation of bax and suppression of bc1-2 may contribute to the apoptosis mechanism.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Cell Line, Tumor; Dose-Response Relationship, Drug; Female; Gene Expression Regulation; Humans; Male; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Stomach Neoplasms; Xanthones