phenanthrenes and Stomach-Neoplasms

The incidence of gastric cancer (GC) ranks fourth among all malignant tumors worldwide, and the fatality rate ranks second among all malignant tumors. Several Chinese traditional medicines have been used in the treatment of advanced gastric cancer. This study aims to investigate the effect of combinational use of natural product cryptotanshinone (CTS) with anti-cancer drug trifluorothymidine (FTD) in GC.. Cell Counting Kit-8 assay was used to detect the inhibitory effect of the combinational or separate use of FTD and CTS on the growth of HGC-27 and AGS GC cells. The combined index of FTD and CTS was calculated using CompuSyn software. To understand the mechanism, we applied flow cytometry to study the cell cycle and cell apoptosis after treatment. We also investigated the amount of FTD incorporated into the DNA by immunofluorescence assay. The expression of relevant proteins was monitored using western blot. Furthermore, the effect of using TAS-102 in combination with CTS was studied in xenograft tumor nude mice model.. FTD and CTS inhibited the growth of GC cells in a dose-dependent manner, respectively. They both exhibited low to sub-micromolar potency in HGC-27 and AGS cells. The combination of FTD and CTS showed synergistic anticancer effect in HGC-27 cells and AGS cells. Our mechanism studies indicate that FTD could block HGC-27 cells at G2/M phase, while CTS could block HGC-27 cells at G1/G0 phase, while FTD combined with CTS could mainly block HGC-27 cells at G2 phase. FTD in combination with CTS significantly increased the apoptosis of HGC-27 cells. We observed that CTS treatment increased the incorporation of FTD into the DNA HGC-27 cell. FTD treatment activated STAT3 phosphorylation in HGC-27 cells, while CTS treatment down-regulated the concentration of p-STAT3. Interestingly, the combination of CTS and FTD reduced STAT3 phosphorylation induced by FTD. In the. FTD combined with CTS has a synergistic anti-gastric cancer effect as shown by

Topics: Animals; Apoptosis; Cell Line, Tumor; Cell Proliferation; Drug Synergism; Heterografts; Humans; Mice; Mice, Nude; Neoplasm Transplantation; Phenanthrenes; STAT3 Transcription Factor; Stomach Neoplasms; Trifluridine

The prognosis of patients with advanced gastric cancer (GC) remains unsatisfactory owing to distant metastasis and resistance to concurrent systemic therapy. Cancer-associated fibroblasts (CAFs), as essential participators in the tumor microenvironment (TME), play a vital role in tumor progression. Thus, CAFs-targeting therapy is appealing for remodeling TME and sensitizing GC to conventional systemic therapy.. Amphiphilic SN38 prodrug polymeric micelles (PSN38) and encapsulated the hydrophobic esterase-responsive prodrug of Triptolide (TPL), triptolide-naphthalene sulfonamide (TPL-nsa), were synthesized to form PSN38@TPL-nsa nanoparticles. Then, CAFs were isolated from fresh GC tissues and immortalized. TPL at low dose concentration was used to investigate its effect on CAFs and CAFs-induced GC cells proliferation and migration. The synergistic mechanism and antitumor efficiency of SN38 and TPL co-delivery nanoparticle were investigated both in vitro and in vivo.. Fibroblast activation protein (FAP), a marker of CAFs, was highly expressed in GC tissues and indicated poorer prognosis. TPL significantly reduced CAFs activity and inhibited CAFs-induced proliferation, migration and chemotherapy resistance of GC cells. In addition, TPL sensitized GC cells to SN38 treatment through attenuated NF-κB activation in both CAFs and GC cells. PSN38@TPL-nsa treatment reduced the expression of collagen, FAP, and α-smooth muscle actin (α-SMA) in tumors. Potent inhibition of primary tumor growth and vigorous anti-metastasis effect were observed after systemic administration of PSN38@TPL-nsa to CAFs-rich peritoneal disseminated tumor and patient-derived xenograft (PDX) model of GC.. TPL suppressed CAFs activity and CAFs-induced cell proliferation, migration and chemotherapy resistance to SN38 of GC. CAFs-targeted TPL and SN38 co-delivery nanoparticles exhibited potent efficacy of antitumor and reshaping TME, which was a promising strategy to treat advanced GC.

Topics: Animals; Antineoplastic Agents; Cancer-Associated Fibroblasts; Cell Line, Tumor; Cell Proliferation; Diterpenes; Drug Synergism; Epoxy Compounds; Female; Humans; Mice; Mice, Inbred BALB C; Micelles; Phenanthrenes; Prodrugs; Stomach Neoplasms; Tumor Microenvironment

This study aimed to identify potential pharmacological targets of triptolide regulating the tumor microenvironment (TME) of stomach adenocarcinoma (STAD) patients. A total of 343 STAD cases from The Cancer Genome Atlas (TCGA) were assigned into high- or low-score groups applying Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE). Hub genes were identified from differentially expressed genes (DEGs) shared by stromal- and immune-related components in the TME of STAD patients using R software. Cox regression analysis was used to identify genes significantly correlated with STAD patient survival. Triptolide target genes were predicted from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). Top 30 genes filtered by Cytohubba from 734 DEGs were screened as hub genes. Forty-two genes were found to be at high risk for STAD prognosis. Thirty-four targets of triptolide were predicted using the TCMSP database. Importantly, C-X-C chemokine receptor type 4 (CXCR4) was identified as a potential target of triptolide associated with the TME in STAD. Analysis of survival highlighted the association between CXCR4 upregulation with STAD progression and poor prognosis. Gene Set Enrichment Analysis (GSEA) confirmed that genes in the CXCR4- upregulated group had significant enrichment in immune-linked pathways. Additionally, triptolide targets were found to be significantly enriched in CXCR4-related chemokine and cancer-related p53 signaling pathways. Molecular docking demonstrated a high affinity between triptolide and CXCR4. In conclusion, CXCR4 may be a therapeutic target of triptolide in the treatment of STAD patients by modulating the TME.

Topics: Adenocarcinoma; Antineoplastic Agents, Alkylating; Computational Biology; Databases, Genetic; Diterpenes; Epoxy Compounds; Humans; Phenanthrenes; Prognosis; Protein Interaction Maps; Stomach Neoplasms; Transcriptome; Tumor Microenvironment

Topics: beta Catenin; Cell Line, Tumor; Cell Movement; Cell Proliferation; Humans; Phenanthrenes; Stomach Neoplasms; Wnt Signaling Pathway; Wnt3A Protein

Gastric cancer is the third leading cause of cancer related mortality worldwide with poor survival rates. Even though a number of chemotherapeutic compounds have been used against this disease, stomach cancer has not been particularly sensitive to these drugs. In this study we have evaluated the effect of triptolide, a naturally derived diterpene triepoxide and its water soluble pro-drug Minnelide on several gastric adenocarcinoma cell lines both as monotherapy and in combination with CPT-11.. Gastric cancer cell lines MKN28 and MKN45 were treated with varying doses of triptolide in vitro. Cell viability was measured using MTT based assay kit. Apoptotic cell death was assayed by measuring caspase activity. Effect of the triptolide pro-drug, Minnelide, was evaluated by implanting the gastric cancer cells subcutaneously in athymic nude mice.. Gastric cancer cell lines MKN28 and MKN45 cells exhibited decreased cell viability and increased apoptosis when treated with varying doses of triptolide in vitro. When implanted in athymic nude mice, treatment with Minnelide reduced tumor burden in both MKN28 derived tumors as well as MKN45 derived tumors. Additionally, we also evaluated Minnelide as a single agent and in combination with CPT-11 in the NCI-N87 human gastric tumor xenograft model.. Our results indicated that the combination of Minnelide with CPT-11 resulted in significantly smaller tumors compared to control. These studies are extremely encouraging as Minnelide is currently undergoing phase 1 clinical trials for gastrointestinal cancers.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Blotting, Western; Camptothecin; Cell Line, Tumor; Cell Proliferation; Cell Survival; Diterpenes; Down-Regulation; Epoxy Compounds; Gene Expression Regulation, Neoplastic; HSP70 Heat-Shock Proteins; Humans; Irinotecan; Mice, Nude; Organophosphates; Phenanthrenes; Prodrugs; Reverse Transcriptase Polymerase Chain Reaction; Sp1 Transcription Factor; Stomach Neoplasms; Tumor Burden; Xenograft Model Antitumor Assays

Gastric cancer is ranked as the third leading cause of cancer-related death in the world. Although extensive efforts have been made in recent decades to treat gastric cancer with various anticancer drugs, effective anti-gastric cancer therapeutics to cure the disease are still lacking in the clinics. Therefore, potent novel anti-gastric cancer drugs are greatly needed. In this study, we explored a novel anti-gastric cancer agent from a medicinal herb named Juncus effusus and found that the active component dehydroeffusol (DHE), a small molecular phenanthrene, effectively inhibited gastric cancer cell proliferation and tumorigenesis by inducing tumor suppressive endoplasmic reticulum (ER) stress and by triggering moderate apoptosis. Mechanistic studies revealed that DHE selectively activated the intracellular tumor suppressive stress response by promoting the overexpression of the key ER stress marker DNA damage-inducible transcript 3 (DDIT3), through upregulation of activating transcription factor 4 (ATF4). Concurrently, DHE suppressed the expression of the cell survival and ER stress marker glucose regulated protein of molecular mass 78 (GRP78) via downregulation of the transcription factor ATF6. In addition, DHE markedly activated the stress response signaling pathway MEKK4-MKK3/6-p38-DDIT3, but significantly inhibited ERK signaling. Our data suggest that DHE inhibits gastric cancer cell growth and tumorigenicity through selectively inducing a robust tumor suppressive ER stress response and a moderate apoptosis response. Therefore, DHE may provide a novel drug candidate for further development of potential anti-gastric cancer therapeutics.

Topics: Activating Transcription Factor 4; Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Line, Tumor; Cell Survival; Endoplasmic Reticulum Chaperone BiP; Endoplasmic Reticulum Stress; Female; Heat-Shock Proteins; Humans; Magnoliopsida; MAP Kinase Signaling System; Membrane Potential, Mitochondrial; Mice, SCID; Phenanthrenes; Stomach Neoplasms; Transcription Factor CHOP; Up-Regulation; Xenograft Model Antitumor Assays

Accumulated data has shown that various vasculogenic tumor cells, including gastric cancer cells, are able to directly form tumor blood vessels via vasculogenic mimicry, supplying oxygen and nutrients to tumors, and facilitating progression and metastasis of malignant tumors. Therefore, tumor vasculogenic mimicry is a rational target for developing novel anticancer therapeutics. However, effective antitumor vasculogenic mimicry-targeting drugs are not clinically available. In this study, we purified 2,7-dihydroxyl-1-methyl-5-vinyl-phenanthrene, termed dehydroeffusol, from the traditional Chinese medicinal herb Juncus effusus L., and found that dehydroeffusol effectively inhibited gastric cancer cell-mediated vasculogenic mimicry in vitro and in vivo with very low toxicity. Dehydroeffusol significantly suppressed gastric cancer cell adhesion, migration, and invasion. Molecular mechanistic studies revealed that dehydroeffusol markedly inhibited the expression of a vasculogenic mimicry master gene VE-cadherin and reduced adherent protein exposure on the cell surface by inhibiting gene promoter activity. In addition, dehydroeffusol significantly decreased the expression of a key vasculogenic gene matrix metalloproteinase 2 (MMP2) in gastric cancer cells, and diminished MMP2 protease activity. Together, our results showed that dehydroeffusol effectively inhibited gastric cancer cell-mediated vasculogenic mimicry with very low toxicity, suggesting that dehydroeffusol is a potential drug candidate for anti-gastric cancer neovascularization and anti-gastric cancer therapy.

Topics: Antigens, CD; Antineoplastic Agents; Cadherins; Cell Adhesion; Cell Line, Tumor; Drugs, Chinese Herbal; Gene Expression Regulation, Neoplastic; Humans; Matrix Metalloproteinase 2; Neovascularization, Pathologic; Phenanthrenes; Stomach Neoplasms

Triptolide has been reported to exhibit antitumor effects in several cancers. This study investigates the mechanism by which triptolide induces apoptosis of gastric cancer cells. Gastric biopsies were collected for histological evaluation and detection of murine double minute 2 (MDM2) expression. Gastric cancer cells were cultured and treated with different concentrations of triptolide at indicated time points. The expression of MDM2, p53 protein, and target proteins including p21, PUMA, and X-linked inhibitor of apoptosis protein (XIAP) was detected. Apoptosis of cells treated with or without triptolide was evaluated. Our results showed that MDM2 protein was overexpressed in gastric cancer (p < 0.01, resp.). Triptolide induced significant apoptosis of gastric cancer cells in a dose- and time-dependent manner (p < 0.05). In addition, treatment with triptolide strongly inhibited the overexpression of MDM2 in gastric cancer cells, and this MDM2 inhibition led to increased levels of p53 protein and inhibition of XIAP (p < 0.05). However, triptolide failed to increase the expression of p53 target protein p21 and PUMA (p > 0.05). In conclusion, triptolide may induce apoptosis of gastric cancer cells via the inhibition of MDM2 overexpression in a p53-independent manner.

Topics: Antineoplastic Agents, Alkylating; Apoptosis; Biomarkers, Tumor; Diterpenes; Dose-Response Relationship, Drug; Epoxy Compounds; Gene Expression Regulation, Neoplastic; Humans; Phenanthrenes; Proto-Oncogene Proteins c-mdm2; Stomach Neoplasms; Tumor Cells, Cultured

Dendrobium nobile is widely used as an analgesic, an antipyretic, and a tonic to nourish the stomach in traditional medicine. Mounting evidence suggests an antitumor activity of denbinobin, a major phenanthrene isolated from stems of Dendrobium nobile. The present study aimed to investigate the inhibitory effect of denbinobin on the invasive ability of human cancer cells. The cytotoxicity of denbonobin was examined in several human cancer cell lines including SK-Hep-1 hepato-carcinoma cells, SNU-484 gastric cancer cells, and HeLa cervix cancer cells. Because SNU-484 cells showed the lowest IC50 value, we examined the effect of denbinobin on the invasive ability of SNU-484 cells. The present study revealed, for the first time, that denbinobin inhibits the invasive phenotype of SNU-484 human gastric cancer cells in a dose-dependent manner. Expressions of matrix metalloproteinase (MMP)-2 and MMP-9 were significantly decreased by denbinobin, suggesting that MMP-2/-9 may be responsible for the anti-invasive activity of denbinobin. We also provide evidence that denbinobin induces apoptosis through down-regulation of Bcl-2 and an up-regulation of Bax. Taken together, this study demonstrates that denbinobin inhibits invasion and induces apoptosis in highly invasive SNU-484 human gastric cancer cells. Given that gastric cancer has been estimated to be one of the most common causes of cancer-related death among Asians and the major cause of death from gastric cancer is the metastatic spread of the disease, our findings may provide useful information regarding the application of denbinobin as a chemopreventive agent that could prevent or alleviate metastatic gastric cancer.

Topics: Anthraquinones; Antineoplastic Agents, Phytogenic; Apoptosis; bcl-2-Associated X Protein; Calgranulin A; Cell Line, Tumor; Cell Proliferation; Chemoprevention; Dendrobium; Down-Regulation; Extracellular Signal-Regulated MAP Kinases; HeLa Cells; Humans; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Matrix Metalloproteinase Inhibitors; Neoplasm Invasiveness; Phenanthrenes; Phenotype; Plant Preparations; Stomach Neoplasms; Up-Regulation

Cisplatin is an anticancer agent that is effective against several types of cancer, including gastric cancer. However, its therapeutic application is limited by its toxicity in normal tissues and complications caused in patients. In this study, we attempted to clarify how triptolide, an active component extracted from the traditional Chinese herbal medicine Tripterygium wilfordii Hook F (TWHF), enhances cisplatin-induced cytotoxicity in gastric cancer SC-M1 cells. After low-dose combined treatments with triptolide and cisplatin, a decrease in viability with a concomitant increase in apoptosis was observed in SC-M1 cells but not in normal cells. Apoptosis induced by the combined treatments was accompanied by loss of mitochondrial membrane potential and release of cytochrome c. Triptolide increased the cisplatin-induced activation of caspase-3 and caspase-9 and the downstream cleavage of PARP in SC-M1 cells. Results of these in vitro experiments indicated that triptolide enhanced cytotoxicity in cisplatin-treated SC-M1 cells and that this effect is mediated by apoptosis through a mitochondrial pathway. Furthermore, using a SCID mouse xenograft model, we demonstrated that the combined treatment completely suppressed tumor growth via down-regulation of proliferating cell nuclear antigen expression without significant side effects. These results suggest that lower concentrations of cisplatin and triptolide used in combination may produce a synergistic anticancer effect that warrants further investigation for its potential clinical applications.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Line, Tumor; Cisplatin; Diterpenes; Drug Synergism; Epoxy Compounds; Humans; Male; Mice; Mice, SCID; Phenanthrenes; Phytotherapy; Plant Extracts; Stomach Neoplasms; Tripterygium; Xenograft Model Antitumor Assays

Gastric adenocarcinoma develops as a consequence of chronic inflammation of the stomach lining that is caused by persistent infection with the bacterium Helicobacter pylori. Gastric carcinogenesis progresses through a sequence of preneoplastic lesions that manifest histologically as atrophic gastritis, intestinal metaplasia, and dysplasia. We show here in several preclinical models of Helicobacter-induced atrophic gastritis, epithelial hyperplasia, and metaplasia that the inhibition of ADP ribosylation by the small-molecule inhibitor PJ34 not only prevents the formation of gastric cancer precursor lesions, but also efficiently reverses preexisting lesions. PJ34 exerts its chemopreventive and therapeutic effects by impairing Helicobacter-specific T-cell priming and T(H)1 polarization in the gut-draining mesenteric lymph nodes. The subsequent infiltration of pathogenic T cells into the gastric mucosa and the ensuing gastric T cell-driven immunopathology are prevented efficiently by PJ34. Our data indicate that PJ34 directly suppresses T-cell effector functions by blocking the IFN-gamma production of mesenteric lymph node T cells ex vivo. Upon exposure to PJ34, purified T cells failed to synthesize ADP-ribose polymers and to activate the transcription of genes encoding IFN-gamma, interleukin 2, and the interleukin 2 receptor alpha chain in response to stimuli such as CD3/CD28 cross-linking or phorbol 12-myristate 13-acetate/ionomycin. The immunosuppressive and chemoprotective effects of PJ34 therefore result from impaired T-cell activation and T(H)1 polarization, and lead to the protection from preneoplastic gastric immunopathology. In conclusion, ADP-ribosylating enzymes constitute novel targets for the treatment of Helicobacter-associated gastric lesions predisposing infected individuals to gastric cancer and may also hold promise for the treatment of other T cell-driven chronic inflammatory conditions and autoimmune pathologies.

Topics: Adenosine Diphosphate; Animals; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Interferon-gamma; Interleukin-2; Lymphocyte Activation; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Phenanthrenes; Poly(ADP-ribose) Polymerase Inhibitors; Precancerous Conditions; Stomach Neoplasms; T-Lymphocytes

Because signal transducer and activator of transcription 3 (STAT3) is constitutively activated in most human solid tumors and is involved in the proliferation, angiogenesis, immune evasion, and antiapoptosis of cancer cells, researchers have focused on STAT3 as a target for cancer therapy. We screened for natural compounds that inhibit the activity of STAT3 using a dual-luciferase assay. Cryptotanshinone was identified as a potent STAT3 inhibitor. Cryptotanshinone rapidly inhibited STAT3 Tyr705 phosphorylation in DU145 prostate cancer cells and the growth of the cells through 96 hours of the treatment. Inhibition of STAT3 Tyr705 phosphorylation in DU145 cells decreased the expression of STAT3 downstream target proteins such as cyclin D1, survivin, and Bcl-xL. To investigate the cryptotanshinone inhibitory mechanism in DU145 cells, we analyzed proteins upstream of STAT3. Although phosphorylation of Janus-activated kinase (JAK) 2 was inhibited by 7 micromol/L cryptotanshinone at 24 hours, inhibition of STAT3 Tyr705 phosphorylation occurred within 30 minutes and the activity of the other proteins was not affected. These results suggest that inhibition of STAT3 phosphorylation is caused by a JAK2-independent mechanism, with suppression of JAK2 phosphorylation as a secondary effect of cryptotanshinone treatment. Continuing experiments revealed the possibility that cryptotanshinone might directly bind to STAT3 molecules. Cryptotanshinone was colocalized with STAT3 molecules in the cytoplasm and inhibited the formation of STAT3 dimers. Computational modeling showed that cryptotanshinone could bind to the SH2 domain of STAT3. These results suggest that cryptotanshinone is a potent anticancer agent targeting the activation STAT3 protein. It is the first report that cryptotanshinone has antitumor activity through the inhibition of STAT3.

Topics: bcl-X Protein; Breast Neoplasms; Cell Growth Processes; Cell Line, Tumor; Cyclin D1; Dimerization; Down-Regulation; Drugs, Chinese Herbal; HCT116 Cells; HeLa Cells; Humans; Inhibitor of Apoptosis Proteins; Luciferases; Male; Microtubule-Associated Proteins; Models, Molecular; Phenanthrenes; Phosphorylation; Prostatic Neoplasms; Protein-Tyrosine Kinases; STAT3 Transcription Factor; Stomach Neoplasms; Survivin

To explore the effects of Tanshinone II A on the proliferation, apoptosis and gene expression of p53 and bcl-2 in human gastric carcinoma MKN-45 cells. Cell count and MTT assay were used to study the proliferation-inhibiting effect of Tanshinone II A on MKN-45 cells. The effect of Tanshinone II A on the cell cycle and apoptosis of MKN-45 cells were examined by propidium iodide (PI) staining and flow cytometry. Semi-quantitative RT-PCR was used to further verify the expression of p53 and bcl-2 gene after exposure to Tanshinone A in MKN-45 cells. The results showed that Tanshinone A significantly inhibited the growth and proliferation of MKN-45 cells in a dose-and time-dependent manner (P<0.05). Tanshinone A arrested MKN-45 cells in G(2)/M phase which led to an obvious accumulation of G(2)/M phase cells while decreased number of G(0)/G(1) phase cells. This resulted in apoptosis of MKN-45 cells and the apoptosis rate was as high as 43.91% after treatment with 2.0 microg/mL Tanshinone II A for 96 h. It was also found that Tanshinone II A up-regulated expression of p53 gene and down-regulated expression of bcl-2 gene. The cytostatic and antiproliferative effect of Tanshinone II A makes it a promising anticancer agent for the treatment of gastric carcinoma.

Topics: Abietanes; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Line, Tumor; Cell Proliferation; Drugs, Chinese Herbal; Gene Expression Regulation, Neoplastic; Humans; Phenanthrenes; Proto-Oncogene Proteins c-bcl-2; Stomach Neoplasms; Tumor Suppressor Protein p53

The retinoblastoma (RB) tumor suppressor protein, pRB, plays an important role in the regulation of mammalian cell cycle. Furthermore, several lines of evidence suggest that pRB also involves in the regulation of apoptosis. In the present study, the degradation of pRB was observed in apoptotic gastric tumor cells treated with a new potent anti-tumor component, tripchlorolide (TC). The inhibition of pRB degradation by a general cysteine protease inhibitor IDAM resulted in the reduction of the apoptotic cells. Furthermore, the survival of the gastric tumor cells under the TC treatment was enhanced by an over-expression of exogenous pRB. These results suggest that the pRB degradation of the gastric tumor cells under the TC treatment involves in the apoptotic progression. In addition, the same extent of TC-induced pRB-degradation was detected in the gastric tumor cells containing a p53 dominant-negative construct, indicating that this kind of pRB degradation is p53-independent.

Topics: Apoptosis; Blotting, Western; Cell Cycle; Cell Line, Tumor; Comet Assay; Cysteine Endopeptidases; Cysteine Proteinase Inhibitors; Cytosol; Diterpenes; DNA Damage; DNA Fragmentation; Electrophoresis, Polyacrylamide Gel; Enzyme Inhibitors; Flow Cytometry; Gene Expression Regulation; Gene Expression Regulation, Neoplastic; Genes, Dominant; Humans; Mitochondria; Phenanthrenes; Plasmids; Proteasome Endopeptidase Complex; Retinoblastoma Protein; Stomach Neoplasms; Tumor Suppressor Protein p53

Triptolide (TPL), a diterpenoid triepoxide purified from the Chinese herb Tripterygium wilfordii Hook F, was tested for its antitumor properties in several model systems. In vitro, TPL inhibited the proliferation and colony formation of tumor cells at extremely low concentrations (2-10 ng/ml) and was more potent than Taxol. Likewise, in vivo, treatment of mice with TPL for 2-3 weeks inhibited the growth of xenografts formed by four different tumor cell lines (B16 melanoma, MDA-435 breast cancer, TSU bladder cancer, and MGC80-3 gastric carcinoma), indicating that TPL has a broad spectrum of activity against tumors that contain both wild-type and mutant forms of p53. In addition, TPL inhibited experimental metastasis of B16F10 cells to the lungs and spleens of mice. The antitumor effect of TPL was comparable or superior with that of conventional antitumor drugs, such as Adriamycin, mitomycin, and cisplatin. Importantly, tumor cells that were resistant to Taxol attributable to the overexpression of the multidrug resistant gene 1 were still sensitive to the effects of TPL. Studies on cultured tumor cells revealed that TPL induced apoptosis and reduced the expression of several molecules that regulate the cell cycle. Taken together, these results suggest that TPL has several attractive features as a new antitumor agent.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antineoplastic Agents; Breast Neoplasms; Cell Division; Diterpenes; Epoxy Compounds; Female; Humans; Melanoma; Melanoma, Experimental; Mice; Neoplasm Metastasis; Phenanthrenes; Stomach Neoplasms; Tumor Cells, Cultured; Urinary Bladder Neoplasms

Triptolide, a major component in the extract of Chinese herbal plant Tripterygium wilfordii Hook f (TWHf), has potential anti-neoplastic effect. In the present study we investigated the potential therapeutic effects and mechanisms of triptolide against human gastric cancer cells. Four gastric cancer cell lines with different p53 status, AGS and MKN-45 (wild type p53); MKN-28 and SGC-7901 (mutant p53) were observed as to cell growth inhibition and induction of apoptosis in response to triptolide treatment. We showed that triptolide inhibited cell growth, induced apoptosis and suppressed NK-kappaB and AP-1 transactivation in AGS cells with wild-type p53. Triptolide induced apoptosis by stimulating the expressions of p53, p21(waf1/cip1), bax protein, and increased the activity of caspases. In addition, it caused cell cycle arrest in the G(0)/G(1) phase. To examine the role of p53 in these functions, we showed that suppression of p53 level with antisense oligonucleotide abrogated triptolide-induced apoptosis and over-expression of dominant negative p53 abolished the inhibitory effect on NF-kappaB activation. Furthermore, we demonstrated that triptolide had differential effects on gastric cancer cells with different p53 status. We showed that triptolide also inhibited cell growth and induced apoptosis in MKN-45 with wild-type p53, whereas it had no significant growth-inhibition and apoptosis induction effects on the MKN-28 and SGC-7901 cells with mutant p53. Our data suggest that triptolide exhibits anti-tumor and anti-inflammatory effects by inhibiting cell proliferation, inducing apoptosis and inhibiting NF-kappaB and AP-1 transcriptional activity. However, a functional p53 is required for these proapoptotic, anti-inflammatory and anti-tumor effects.

Topics: Apoptosis; bcl-2-Associated X Protein; Blotting, Western; Caspase 3; Caspases; Cell Cycle; Cell Division; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Diterpenes; DNA; Dose-Response Relationship, Drug; Electrophoretic Mobility Shift Assay; Epoxy Compounds; Flow Cytometry; Gene Expression Regulation, Neoplastic; Humans; NF-kappa B; Oligonucleotides, Antisense; Phenanthrenes; Poly(ADP-ribose) Polymerases; Protein Binding; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Stomach Neoplasms; Transcription Factor AP-1; Transcriptional Activation; Tumor Cells, Cultured; Tumor Suppressor Protein p53

Chinese herbs nephropathy (CHN), a rapidly progressive interstitial fibrosis of the kidney, has been described in approximately 100 young Belgian women who had followed a slimming regimen containing some Chinese herbs. In 4 patients multifocal transitional cell carcinomas (TCC) were observed. Aristolochic acid (AA), suspected as the causal factor of CHN, is a well known carcinogen but its ability to induce fibrosis has never been demonstrated. The objective of this study was to evaluate the latter using doses of AA, durations of intoxication and delays of sacrifice known to yield tumours in rats. We also tested the hypothesis that a possible fibrogenic role of AA was enhanced by the other components of the slimming regimen. Male and female rats were treated orally with 10 mg isolated AA/kg per day for 5 days/week, or with approximately 0.15 mg AA/ kg per day 5 days/week contained in the herbal powder together with the other components prescribed in the slimming pills for 3 months. The animals were killed respectively 3 and 11 months later. At sacrifice, animals in both groups had developed the expected tumours but not fibrosis of the renal interstitium. Whether the fibrotic response observed in man is due to species and/or strain related differences in the response to AA or to other factors, remains to be determined. Interestingly, despite the addition of fenfluramine and diethylpropion, two drugs incriminated in the development of valvular heart disease, no cardiac abnormalities were observed.

Topics: Animals; Anti-Obesity Agents; Aristolochic Acids; Carcinogens; Drugs, Chinese Herbal; Female; Fibrin; Male; Nephritis, Interstitial; Phenanthrenes; Rats; Rats, Wistar; Stomach Neoplasms

Binding of the naturally occurring carcinogen, aristolochic acid I (AAI), to DNA in male Wistar rats has been examined. Rats were treated orally with a single dose (13.8 mmol) of AAI and sacrificed 1 day and 1, 2, 4, 16 and 36 weeks after treatment. The formation and persistence of two specific purine AAI-DNA adducts were studied utilizing the nuclease P1 enhancement method of the 32P-postlabelling assay. Both adducts, 7-(deoxyadenosin-N6-yl)-aristolactam I (dA-AAI) and 7-(deoxyguanosin-N2-yl)-aristolactam I (dG-AAI), were detectable for up to 36 weeks in all target (forestomach) and non-target (glandular stomach, liver, lung, urinary bladder) organs and showed differential rates of removal and persistence. In all organs, dA-AAI was the major adduct present. In the target organ (forestomach), both adducts were removed rapidly within the first two weeks; thereafter, extensive removal of dG-AAI continued, whereas dA-AAI attained constant levels (4-36 weeks). Of interest was the marked decrease of both adducts in glandular stomach, the neighbouring non-target tissue to the forestomach. These results suggest that the persistence of a specific AAI-DNA adduct, namely dA-AAI, in the target organ may be the critical lesion responsible for initiation of carcinogenesis by AAI.

Topics: Animals; Aristolochic Acids; Carcinogens; Deoxyadenosines; Deoxyguanosine; DNA; DNA Damage; Gastric Mucosa; Male; Phenanthrenes; Phosphorus Radioisotopes; Rats; Rats, Wistar; Stomach; Stomach Neoplasms; Tissue Distribution

In this study the development of aristolochic acid (AA) induced tumors in rats with and without diallyl sulfide (DAS) was studied. Experiments were also conducted to establish the effects of DAS administration on AA-derived DNA single-stranded regions and DNA adduct formation in the forestomach of such animals. Forestomach, urinary bladder and thymus tumors were induced in male BD-6 rats after oral treatment for 12 weeks with AA (2 x 10 mg/kg/week). Administration of 150 mg/kg DAS intragastrically 4 h prior to AA treatment reduced significantly the number of rats that developed forestomach tumors (6-9 months after the start of experiment). The incidence of AA-induced forestomach tumors was 10% (two out of 20 rats) after co-administration of DAS and 60% (12 out of 20 animals) when AA was administered alone. The high dose of DAS (2 x 150 mg/kg) markedly inhibited the formation of squamous cell carcinomas in the forestomach. However, the thioether did not prevent the formation of forestomach and urinary bladder papillomatosis. Additionally, DAS co-administration decreased the accumulation of single-stranded regions in rat forestomach DNA. Using the nuclease P1 enhancement method of the 32P-postlabeling assay, a decrease in the level of AA-derived adducts was also detected after co-administration of DAS. We conclude that the decrease of DNA damage after DAS co-administration is associated with the delay in conversion of papillomas to malignant forestomach tumors.

Topics: Allyl Compounds; Animals; Antineoplastic Agents; Aristolochic Acids; Carcinogens; DNA; DNA Damage; Dose-Response Relationship, Drug; Male; Phenanthrenes; Rats; Stomach Neoplasms; Sulfides

Triptolide (Tri) is a diterpenoid triepoxide isolated from Tripterygium wilfordii Hook F. The effects of Tri on the colony formation of breast cancer cell lines MCF-7 and BT-20, stomach cancer cell lines MKN-45, MKN-7, and KATO-III, and promyelocytic leukemia cell line HL-60 were reported. Using Hamburger-Salmon's double layer agar technique with certain modifications, cancer cells were cultured in 0.3% agar in a highly humidified atmosphere of 5% CO2 at 37 degrees C for 14-21 d. Colonies were counted on d 14 (occasionally d 21) with the colony analyzer system CA-7A. Of the 5 solid tumor cell lines tested, 4 showed diminished colony formation in soft agar by greater than 70% of control value in Tri 10(-8) mol.L-1 (continuous exposure). The magnitudes of the inhibitory effect of Tri on most breast and stomach cancer cell lines were similar to that on the leukemia cell line HL-60. IC50 were 0.504-1.22 micrograms.L-1. The clinically achievable peak plasma concentration (PPC) of Tri was estimated as 0.15 mg.L-1, being 72-126 times higher than the IC70 of the cancer cell lines except KATO-III. The results suggest that Tri might have a potential therapeutic effect on some types of solid tumors, e.g., breast and stomach cancers.

Topics: Antineoplastic Agents; Breast Neoplasms; Diterpenes; Epoxy Compounds; Humans; Leukemia, Promyelocytic, Acute; Phenanthrenes; Stomach Neoplasms; Tumor Cells, Cultured; Tumor Stem Cell Assay

The histopathogenesis of rat forestomach carcinoma induced experimentally with aristolochic acid was investigated. The intragastric administration of 10 mg/kg/day caused extensive necrosis of the squamous epithelium, followed by regeneration and hyperplasia, papilloma formation and ultimately by invasive squamous cell carcinoma.

Topics: Animals; Antineoplastic Agents; Aristolochic Acids; Hyperplasia; Male; Neoplasms, Experimental; Papilloma; Phenanthrenes; Rats; Rats, Inbred Strains; Stomach; Stomach Neoplasms