phenanthrenes and Pancreatic-Neoplasms

Triptolide, a compound isolated from a Chinese medicinal herb, possesses potent antitumor, immunosuppressive, and anti-inflammatory properties, but is clinically limited due to its poor solubility, bioavailability, and toxicity. Recently, Minnelide, a water-soluble prodrug of triptolide, was shown to have potent antitumor activity in various preclinical cancer models. Minnelide is currently in Phase II clinical trials for treatment of advanced pancreatic cancer, which has fueled increased interest in this promising agent. Here, we review the recent advances in the biological activity of triptolide and its analogs, their mechanisms of actions, and their clinical developments. A special emphasis is given to proteins and pathways within the tumor and stromal compartments that are targeted by triptolide and its analogs as well as the ongoing clinical trials.

Topics: Animals; Antineoplastic Agents; Diterpenes; Epoxy Compounds; Humans; Immunosuppressive Agents; Pancreatic Neoplasms; Phenanthrenes

The heat shock response in pancreatitis that is activated via HSP70 protects acinar cells through multiple simultaneous mechanisms. It inhibits trypsinogen activation and modulates NF-κB signaling to limit acinar cell injury. On the other hand, HSP70 is overexpressed in pancreatic cancer and is hijacked by the cellular machinery to inhibit apoptosis. Inhibition of HSP70 in pancreatic cancer by a novel compound, Minnelide, has shown considerable clinical promise.

Topics: Animals; Clinical Trials, Phase I as Topic; Diterpenes; Epoxy Compounds; HSP70 Heat-Shock Proteins; Humans; Neoplastic Stem Cells; Organophosphates; Pancreatic Neoplasms; Pancreatitis; Phenanthrenes

Pancreatic cancer is the 10th leading cause of all new cancer cases for men and the fourth leading cause of death across genders, having very poor prognosis and survival rates. The current standard of care Gemcitabine fails to add any survival benefit for this disease (www.cancer.gov). Though the incidence of pancreatic cancer is found to be higher in developed countries, the aggressive biology of the cancer, its high rate of recurrence and chemo-resistance make it a formidable disease in all parts of the globe. Hepatocellular carcinoma (HCC) or liver cancer, on the other hand affects almost 750,000 people world wide with 84% of the cases coming from underdeveloped or developing countries. Our studies show that Minnelide, a water soluble pro-drug of triptolide (active compound from a chinese herb) is very effective against a number of malignant diseases.. The current study discusses the efficacy of this compound in pancreatic and liver cancer.

Topics: Animals; Antineoplastic Agents, Alkylating; Diterpenes; Epoxy Compounds; Humans; Liver Neoplasms; Organophosphates; Pancreatic Neoplasms; Phenanthrenes; Prodrugs

Topics: Animals; Cell Line, Tumor; Dextrans; Diterpenes; Epoxy Compounds; Mice; Molecular Targeted Therapy; Mutation; Pancreatic Neoplasms; Phenanthrenes; Proto-Oncogene Proteins p21(ras); Tumor Microenvironment

Addition of nab-paclitaxel to gemcitabine offers a survival benefit of only 6 weeks over gemcitabine alone at a cost of increased toxicity in PDAC. The goal of the present study is to evaluate the efficacy of Minnelide, a water-soluble prodrug of triptolide, in combination with the standard of care regimen for chemotherapy with the added advantage of reducing the doses of these drugs to minimize toxicity. Pancreatic cancer cell lines were implanted subcutaneously or orthotopically in athymic nude or C57BL/6J mice. Subsequently, animals were randomized and received saline or minnelide or full dose chemotherapy or low dose chemotherapy or minnelide in combination with low dose chemotherapy. Our results show that a combination of low doses of Minnelide with Gemcitabine + nab-paclitaxel significantly inhibited tumor progression and increased the survival of tumor-bearing mice in comparison with conventional chemotherapy alone. Moreover, combination therapy significantly reduced cancer-related morbidity by decreasing ascites and metastasis and effectively targeted both cancer and the associated stroma. In vitro studies with a combination of low doses of triptolide and paclitaxel significantly decreased the cell viability, increased apoptosis and led to significantly increased M-phase cell cycle arrest in various pancreatic cancer cell lines as compared to either drug alone. Our results show that Minnelide synergizes with conventional chemotherapy leading to a significant reduction in the doses of these toxic drugs, all the while achieving better efficacy in the treatment of PDAC. This combination effectively targeted both the cancer and the associated stromal components of pancreatic cancer.

Topics: Albumins; Animals; Antineoplastic Combined Chemotherapy Protocols; Cell Line, Tumor; Diterpenes; Epoxy Compounds; Mice; Mice, Inbred C57BL; Organophosphates; Paclitaxel; Pancreatic Neoplasms; Phenanthrenes; Xenograft Model Antitumor Assays

Topics: Carcinogenesis; Cell Line, Tumor; Cell Transformation, Neoplastic; Colorectal Neoplasms; Glutamine; Humans; Lipids; Lipogenesis; Pancreatic Neoplasms; Phenanthrenes; Proto-Oncogene Proteins p21(ras); Reactive Oxygen Species; Signal Transduction

We report a series of copper(II) artificial metallo-nucleases (AMNs) and demonstrate their DNA damaging properties and in-vitro cytotoxicity against human-derived pancreatic cancer cells. The compounds combine a tris-chelating polypyridyl ligand, di-(2-pycolyl)amine (DPA), and a DNA intercalating phenanthrene unit. Their general formula is Cu-DPA-N,N' (where N,N'=1,10-phenanthroline (Phen), dipyridoquinoxaline (DPQ) or dipyridophenazine (DPPZ)). Characterisation was achieved by X-ray crystallography and continuous-wave EPR (cw-EPR), hyperfine sublevel correlation (HYSCORE) and Davies electron-nuclear double resonance (ENDOR) spectroscopies. The presence of the DPA ligand enhances solution stability and facilitates enhanced DNA recognition with apparent binding constants (K

Topics: Cell Line, Tumor; Coordination Complexes; Copper; Crystallography, X-Ray; DNA; DNA Damage; Electron Spin Resonance Spectroscopy; Humans; Organometallic Compounds; Pancreatic Neoplasms; Phenanthrenes; Phenanthrolines

Triptolide (TP) is a diterpene epoxide component extracted from Tripterygium wilfordii and has been shown to possess an impressive anticancer effect. However, TP has not yet entered any clinic trials due to the severe adverse effects that resulted from the off-target absorption and distribution found in animal studies. In this study, we designed and synthesized three amino acids (tryptophan, valine, and lysine) based TP prodrugs to target ATB

Topics: Amino Acid Transport Systems; Antineoplastic Agents; Cell Line; Cell Proliferation; Cell Survival; Diterpenes; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Epoxy Compounds; Humans; Molecular Conformation; Pancreatic Neoplasms; Phenanthrenes; Prodrugs; Structure-Activity Relationship

According to the special physiological and pharmacological activities of natural compounds, many drugs with special therapeutic effects have been developed. The Triptolide (TP) is a natural anti-tumor drug with a world patent, but its target and mechanism are yet unknown.. The study aims to explore and predict the target and mechanism of TP on Non-Small Cell Lung Cancer (NSCLC), Pancreatic Cancer (PC) and Colorectal Cancer (CC) through network pharmacology technology.. We screened the core targets of TP with NSCLC, PC and CC, respectively, and carried out network analysis, enrichment analysis and ligand-receptor docking to clarify its potential pharmacological mechanism.. By screening the core genes between TP with NSCLC, PC and CC, respectively, it was found that PTGS2 was the common target gene in the three cancers. NSCLC, CCL2, IL6, HMOX1 and COL1A1 are the specific target genes, while MMP2, JUN, and CXCL8 are the specific target genes in PC. In CC, the specific target genes includeERBB2, VEGFA, STAT1 and MAPK8. In enrichment analysis, it was found that the NF- κB, toll-like receptors and IL-17 signaling pathway were mainly involved in TP for these cancers. The binding energy of TP to the core target is less than that of cyclophosphamide.. This study preliminarily revealed that TP may prevent and treat cancers\\ through multiple targets and pathways. The possible mechanisms of TP include regulating immune and inflammatory responses, promoting apoptosis and inhibiting tumor development. It shows that TP may have potential in treating kinds of tumors.

Topics: Antineoplastic Agents, Alkylating; Carcinoma, Non-Small-Cell Lung; Chemokine CCL2; Collagen Type I, alpha 1 Chain; Colorectal Neoplasms; Cyclooxygenase 2; Diterpenes; Epoxy Compounds; Heme Oxygenase-1; Humans; Interleukin-17; Interleukin-6; Interleukin-8; Lung Neoplasms; Matrix Metalloproteinase 2; Mitogen-Activated Protein Kinase 8; Molecular Docking Simulation; Molecular Targeted Therapy; Network Pharmacology; NF-kappa B; Pancreatic Neoplasms; Phenanthrenes; Proto-Oncogene Proteins c-jun; Receptor, ErbB-2; STAT1 Transcription Factor; Structure-Activity Relationship; Toll-Like Receptors; Vascular Endothelial Growth Factor A

The phosphorylation of pyruvate dehydrogenase (PDH) by pyruvate dehydrogenase kinase (PDK) 4 inhibits its ability to induce a glycolytic shift. PDK4 expression is upregulated in various types of human cancer. Because PDK4 regulation is critical for metabolic changes in cancer cells, it is an attractive target for cancer therapy given its ability to shift glucose metabolism. It was previously shown that a novel PDK4 inhibitor, cryptotanshinone (CPT), suppressed the three‑dimensional (3D)‑spheroid formation of pancreatic and colorectal cancer cells. In the present study, the effects of CPT on the invasiveness of bladder cancer cells were investigated. CPT significantly suppressed the invasiveness and 3D‑spheroid formation of T24 and J82 bladder cancer cells. CPT also suppressed the phosphorylation of PDH and β‑catenin, as well as the expression of N‑cadherin, which are all critical for inducing epithelial‑mesenchymal transition (EMT). The knockdown of β‑catenin or PDK4 using specific small interfering RNAs suppressed N‑cadherin expression and invasiveness in T24 cells. An mTOR inhibitor also suppressed the phosphorylation of β‑catenin and N‑cadherin expression. Furthermore, CPT injection significantly suppressed pancreatic tumor growth and peritoneal dissemination of highly metastatic SUIT‑2 pancreatic cancer cells in a mouse orthotopic pancreatic cancer model, without evident toxicity. Moreover, immunohistochemistry analyses demonstrated decreased β‑catenin expression in CPT‑treated pancreatic tumors compared with control tumors. Taken together, these results indicate that CPT reduced the invasiveness and metastasis of bladder cancer cells by suppressing EMT via the mTOR/β‑catenin/N‑cadherin pathway.

Topics: Animals; Antigens, CD; Antineoplastic Agents; beta Catenin; Cadherins; Cell Line, Tumor; Female; Humans; Mice, Inbred BALB C; Mice, Nude; Pancreatic Neoplasms; Phenanthrenes; Pyruvate Dehydrogenase Acetyl-Transferring Kinase; Signal Transduction; Spheroids, Cellular; TOR Serine-Threonine Kinases; Urinary Bladder Neoplasms; Xenograft Model Antitumor Assays

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease exhibiting the poorest prognosis among solid tumors. The efficacy of conventional therapies has been hindered largely due to the insufficient chemotherapeutic delivery to the dense desmoplastic tumor stroma, and the extremely high or toxic dose needed for chemotherapy. Traditional Chinese Medicine (TCM) contains effective components that can effectively regulate tumor microenvironment and kill tumor cells, providing promising alternatives to PDAC chemotherapy. In this study, two active drug monomers of TCM were screened out and a sequentially targeting delivery regimen was developed to realize the optimized combinational therapy. Transforming growth factor-β (TGF-β) plays an indispensable role in promoting cancer-associated fibroblasts (CAFs) activation and proliferation, and CAFs have caused major physical barriers for chemotherapeutic drug delivery. Herein, CAFs-targeting biodegradable polymer nanoparticle (CRE-NP(α-M)) coated with CREKA peptide and loaded with TCM α-mangostin (α-M) was developed to modulate tumor microenvironment by interfering of TGF-β/Smad signaling pathway. Low pH-triggered micelle modified with CRPPR peptide and loaded with another TCM triptolide was constructed to increase the therapeutic effect of triptolide at the tumor sites and reduced its damage to main organs. As expected, CRE-NP(α-M) effectively inactived CAFs, reduced extracellular matrix production, promoted tumor vascular normalization and enhanced blood perfusion at the tumor site. The sequentially targeting drug delivery regimen, CRP-MC(Trip) following CRE-NP(α-M) pretreatment, exhibited strong tumor growth inhibition effect in the orthotopic tumor model. Hence, sequentially targeting delivery of nanoformulated TCM offers an efficient approach to overcome the permeation obstacles and improve the effect of chemotherapy on PDAC, and provides a novel option to treat desmoplastic tumors.

Topics: Carcinoma, Pancreatic Ductal; Diterpenes; Epoxy Compounds; Humans; Pancreatic Neoplasms; Phenanthrenes; Tumor Microenvironment; Xanthones

Tripterygium wilfordii Hook F (TwHF) exhibits anti-tumor efficacy in pancreatic ductal adenocarcinoma (PDAC), however the pharmacological mechanisms are unclear due to complicated formulae and target genes. Using Traditional Chinese Medicine Systems Pharmacology and GeneCards databases, we performed a network pharmacology (NP) of TwHF and screened out 22 ingredients and 25 target genes associated with PDAC. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of the 25 target genes were performed. Using STRING database, protein-protein interaction network of the 25 target genes was constructed, and indicated that triptolide (TL)-plasminogen activator urokinase (PLAU) as a potential target for PDAC treatment. Hence, in vitro experiments were performed and validated that TL inhibited PDAC cell proliferation and migration by suppressing PLAU expression. The results of Western blot suggested that PLAU activated endothelial-mesenchymal transition (EMT) progression. In two Gene Expression Omnibus datasets (GSE16515 and GSE28735), PLAU was up-regulated in tumor tissues, and PLAU overexpression was associated with poor overall survival of PDAC cohort of The Cancer Genome Atlas (P < 0.01). Immunohistochemistry illustrated that overexpression of PLAU protein was related to lymph node metastasis in 20 PDAC patients (P < 0.01). Based on NP of TwHF, we identified and validated that TL-PLAU could serve as a potential target for PDAC treatment.

Topics: Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Cell Movement; Cell Proliferation; Diterpenes; Down-Regulation; Drugs, Chinese Herbal; Epoxy Compounds; Gene Expression Regulation, Neoplastic; Humans; Pancreatic Neoplasms; Phenanthrenes; Tripterygium; Urokinase-Type Plasminogen Activator

The poly(ADP-ribose) polymerases (PARP) play important roles in repairing damaged DNA during intrinsic cell death. We recently linked PARP-1 to death receptor (DR)-activated extrinsic apoptosis, the present studies sought to elucidate the function of cytoplasmic PARP-1 in pancreatic cancer tumorigenesis and therapy. Using human normal and pancreatic cancer tissues, we analyzed the prevalence of cytoplasmic PARP-1 expression. In normal human pancreatic tissues, PARP-1 expression was present in the nucleus; however, cytoplasmic PARP-1 expression was identified in pancreatic cancers. Therefore, cytoplasmic PARP-1 mutants were generated by site-direct mutagenesis, to determine a causative effect of cytoplasmic PARP-1 on pancreatic cancer tumorigenesis and sensitivity to therapy with TRA-8, a humanized DR5 antibody. PARP-1 cytoplasmic mutants rendered TRA-8 sensitive pancreatic cancer cells, BxPc-3 and MiaPaCa-2, more resistant to TRA-8-induced apoptosis; whereas wild-type PARP-1, localizing mainly in the nucleus, had no effects. Additionally, cytoplasmic PARP-1, but not wild-type PARP-1, increased resistance of BxPc-3 cells to TRA-8 therapy in a mouse xenograft model in vivo. Inhibition of PARP enzymatic activity attenuated cytoplasmic PARP-1-mediated TRA-8 resistance. Furthermore, increased cytoplasmic PARP-1, but not wild-type PARP-1, was recruited into the TRA-8-activated death-inducing signaling complex and associated with increased and sustained activation of Src-mediated survival signals. In contrast, PARP-1 knockdown inhibited Src activation. Taken together, we have identified a novel function and mechanism underlying cytoplasmic PARP-1, distinct from nuclear PARP-1, in regulating DR5-activated apoptosis. Our studies support an innovative application of available PARP inhibitors or new cytoplasmic PARP-1 antagonists to enhance TRAIL therapy for TRAIL-resistant pancreatic cancers.

Topics: Animals; Antibodies, Monoclonal; Cell Nucleus; Cell Proliferation; Cell Survival; Cytoplasm; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; Humans; Male; Mice; Mutagenesis, Site-Directed; Neoplasm Grading; Neoplasm Transplantation; Pancreatic Neoplasms; Phenanthrenes; Poly (ADP-Ribose) Polymerase-1; Receptors, TNF-Related Apoptosis-Inducing Ligand; Signal Transduction; Up-Regulation

Topics: 3T3 Cells; Animals; Antineoplastic Agents, Alkylating; Apoptosis; Cell Line, Tumor; Cell Proliferation; Diterpenes; Epoxy Compounds; Hedgehog Proteins; Humans; Mice; Pancreatic Neoplasms; Phenanthrenes; Signal Transduction; Small Molecule Libraries

Survival of KRAS mutant pancreatic cancer is critically dependent on reprogrammed metabolism including elevated macropinocytosis, autophagy, and lysosomal degradation of proteins. Lysosomal acidification is indispensable to protein catabolism, which makes it an exploitable metabolic target for KRAS mutant pancreatic cancer. Herein we investigated ultra-pH-sensitive micelles (UPSM) with pH-specific buffering of organelle pH and rapid drug release as a promising therapy against pancreatic cancer. UPSM undergo micelle-unimer phase transition at their apparent p K

Topics: Animals; Antineoplastic Agents, Alkylating; Cell Line, Tumor; Delayed-Action Preparations; Diterpenes; Drug Delivery Systems; Drug Liberation; Epoxy Compounds; Humans; Hydrogen-Ion Concentration; Lysosomes; Male; Mice, Inbred BALB C; Mice, Nude; Micelles; Mutation; Pancreatic Neoplasms; Phenanthrenes; Proto-Oncogene Proteins p21(ras)

Triptolide (TPL) can enhance the sensitivity of pancreatic cancer cells to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), but available research is limited to whether TPL can affect the relevant downstream signaling pathways of TRAIL. Current knowledge is far from adequate to fully understand the mechanisms by which TPL increases TRAIL sensitivity of pancreatic cancer.. We aimed to find TPL-regulated upstream components of the signaling pathways of TRAIL to further understand the regulatory mechanism by which TPL increases the sensitivity to TRAIL.. Microarray analysis and the adherent cell cytometry system Celigo were used to identify the TRAIL-related genes. Western blot analysis, cell proliferation assays, tumorigenicity assays in nude mice, flow cytometry, and transmission electron microscopy were performed to analyze the function of Pumilio RNA-binding family member 1 (PUM1) in TPL-mediated enhancement of sensitivity to TRAIL. The effect of PUM1 silencing on the p27-CDK2 complex was examined by immunoprecipitation.. PUM1 expression was decreased by TPL and TPL + TRAIL but was not decreased by TRAIL alone. PUM1 silencing enhanced low-concentration-TRAIL-induced suppression of proliferation and promotion of apoptosis and increased p27 expression and the amount of the p27-CDK2 complex in pancreatic cancer cells. PUM1 overexpression attenuated the effects of TPL treatment (TRAIL-induced cell proliferation suppression and apoptosis promotion), while PUM1 silencing and TPL enhanced low-concentration-TRAIL-induced autophagy activation in pancreatic cancer cells. Moreover, PUM1 overexpression attenuated the effect of TPL treatment on TRAIL-induced autophagy activation in pancreatic cancer cells.. PUM1 silencing increased the sensitivity of pancreatic cancer cells to TRAIL in vivo and in vitro, indicating that PUM1 may be a new target for increasing the sensitivity of cancer cells to TRAIL. In addition, our results indicate that TPL enhances TRAIL sensitivity of pancreatic cancer cells by activating autophagy via downregulation of PUM1. This novel concept may have significant implications for the development of new strategies to enhance TRAIL sensitivity of tumors.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Autophagy; Cell Line, Tumor; Cell Proliferation; Diterpenes; Down-Regulation; Epoxy Compounds; Gene Expression Regulation, Neoplastic; Humans; Mice, Nude; Pancreatic Neoplasms; Phenanthrenes; RNA-Binding Proteins; TNF-Related Apoptosis-Inducing Ligand; Xenograft Model Antitumor Assays

The widespread involvement of the Hedgehog (Hh) signaling pathway in human malignancies has motivated the clinical development of Smoothened (Smo) antagonists, such as vismodegib and sonidegib. However, Smo antagonists have failed to benefit patients suffering from Hh pathway-dependent solid tumors, such as pancreatic, colorectal, or ovarian cancer. Hh-dependent cancers are often driven by activating mutations that occur downstream of Smo and directly activate the transcription factors known as glioma-associated oncogenes (

Topics: A549 Cells; Animals; Area Under Curve; Cell Proliferation; Fibroblasts; Half-Life; Hedgehog Proteins; Hep G2 Cells; Humans; Liver X Receptors; Lung Neoplasms; Mice; Mice, Inbred BALB C; NIH 3T3 Cells; Oxysterols; Pancreatic Neoplasms; Phenanthrenes; Pregnenolone; Signal Transduction; Smoothened Receptor; Transcriptional Activation; Transfection; Zinc Finger Protein GLI1

Resident fibroblasts that contact tumor epithelial cells (TEC) can become irreversibly activated as cancer-associated-fibroblasts (CAF) that stimulate oncogenic signaling in TEC. In this study, we evaluated the cross-talk between CAF and TEC isolated from tumors generated in a mouse model of KRAS/mut p53-induced pancreatic cancer (KPC mice). Transcriptomic profiling conducted after treatment with the anticancer compound Minnelide revealed deregulation of the TGFβ signaling pathway in CAF, resulting in an apparent reversal of their activated state to a quiescent, nonproliferative state. TEC exposed to media conditioned by drug-treated CAFs exhibited a decrease in oncogenic signaling, as manifested by downregulation of the transcription factor Sp1. This inhibition was rescued by treating TEC with TGFβ. Given promising early clinical studies with Minnelide, our findings suggest that approaches to inactivate CAF and prevent tumor-stroma cross-talk may offer a viable strategy to treat pancreatic cancer.

Topics: Animals; Apoptosis; Cancer-Associated Fibroblasts; Carcinogenesis; Carcinoma, Pancreatic Ductal; Cell Proliferation; Disease Models, Animal; Diterpenes; Epithelial Cells; Epoxy Compounds; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Mice; Mice, Inbred C57BL; Mutation; Organophosphates; Pancreatic Neoplasms; Phenanthrenes; Proto-Oncogene Proteins p21(ras); Signal Transduction; Transforming Growth Factor beta; Tumor Cells, Cultured; Tumor Suppressor Protein p53

Triptolide induces apoptosis and DNA damage followed by inhibition of DNA repair associated gene expression. However, there is the limited data for biomarker to predict the benefit to triptolide in various cancers including pancreatic cancer.. We investigated the anti tumor efficacy of triptolide in various pancreatic cancer cell lines (Capan-1, Capan-2, SNU-213, SNU-410, HPAFII, and Hs766T) and patient derived cells (PDCs) from metastatic pancreatic cancer patients.. In vitro cell viability assay for triptolide in 6 PC cell lines, the IC. Our findings might be helpful to completely capture the subset of patients who may benefit to tripolide (minnelide). More robust biomarkers such as KRAS mutation and Chk2 phosphorylation and careful clinical trial design using triptolide (minnelide) are warranted.

Topics: Antineoplastic Agents, Alkylating; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cell Survival; Computational Biology; Diterpenes; DNA Damage; DNA Repair; Epoxy Compounds; Gene Expression; Gene Expression Profiling; Gene Ontology; Gene Regulatory Networks; Humans; Pancreatic Neoplasms; Phenanthrenes; ras Proteins; Signal Transduction; Transcriptome

Pancreatic cancer is a lethal disease with a dreadful 5-year survival rate of only 5%. In spite of several treatment options, the prognosis still remains extremely poor. Therefore, novel therapy strategies with combinations of drugs are urgently required to combat this fatal disease. Triptolide (TPL) and celastrol (CL), two main compounds in traditional Chinese medicine isolated from Thunder God Vine, have a broad range of bioactivities including anticancer activity. Silk fibroin (SF), a naturally occurring protein with several unique properties, is an ideal carrier material. In this study, we prepared TPL and CL loaded silk fibroin nanoparticles (TPL-SFNPs and CL-SFNPs) by a modified desolvation method and evaluated their synergistic effects against human pancreatic cancer cells. Both SFNPs were characterized for particle size and zeta potential. The entrapment efficiency, drug loading, and drug release profiles were evaluated by HPLC. The cytotoxicity and synergistic effect of SFNPs were investigated in MIA PaCa-2 and PANC-1 human pancreatic cells. The results showed that the particle sizes of TPL-SFNPs and CL-SFNPs were 166.4 ± 4.6 nm and 170.4 ± 2.3 nm, with a mean zeta potential -27.2 ± 2.0 mV and -25.5 ± 2.57 mV, respectively. TPL-SFNPs and CL-SFNPs have a drug loading of 57.0 ± 4.7 μg mg

Topics: Cell Line, Tumor; Diterpenes; Drug Synergism; Epoxy Compounds; Fibroins; Humans; Nanoparticles; Pancreatic Neoplasms; Pentacyclic Triterpenes; Phenanthrenes; Triterpenes

Pancreatic tumors are renowned for their extremely hypoxic centers, resulting in upregulation of a number of hypoxia mediated signaling pathways including cell proliferation, metabolism and cell survival. Previous studies from our laboratory have shown that Minnelide, a water-soluble pro-drug of triptolide (anti-cancer compound), decreases viability of cancer cells in vitro as well as in vivo. However, its mechanism of action remain elusive. In the current study we evaluated the effect of Minnelide, on hypoxia mediated oncogenic signaling as well as stemness in pancreatic cancer. Minnelide has just completed Phase 1 trial against GI cancers and is currently awaiting Phase 2 trials. Our results showed that upon treatment with triptolide, HIF-1α protein accumulated in pancreatic cancer cells even though hypoxic response was decreased in them. Our studies showed even though HIF-1α is accumulated in the treated cells, there was no decrease in HIF-1 binding to hypoxia response elements. However, the HIF-1 transcriptional activity was significantly reduced owing to depletion of co-activator p300 upon treatment with triptolide. Further, treatment with triptolide resulted in a decreased activity of Sp1 and NF-kB the two major oncogenic signaling pathway in pancreatic cancer along with a decreased tumor initiating cell (TIC) population in pancreatic tumor.

Topics: Animals; Carcinogenesis; Cell Hypoxia; Cell Line, Tumor; Cell Proliferation; Diterpenes; Epoxy Compounds; Gene Expression Regulation, Neoplastic; Humans; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; Mice, SCID; Neoplastic Stem Cells; Organophosphates; Pancreatic Neoplasms; Phenanthrenes; Signal Transduction; Xenograft Model Antitumor Assays

Minnelide is an experimental antineoplastic agent that is currently the subject of a phase 1 clinical trial for the treatment of pancreatic and gastrointestinal malignancies. In this study, we documented two cases of reversible acute cerebellar toxicity (REACT) associated with Minnelide and compared its radiological manifestations with other cerebellotoxic agents.. Both patients had histories of progressive metastatic cancer and participated in a phase 1 clinical trial with Minnelide. They had an MRI examination including T2WI, FLAIR and SWI, axial and coronal DWI, and ADC map on admission and follow up.. In each patient, the initial MRI demonstrated increased signal on FLAIR and restricted diffusion in the cerebellar cortex without involvement of deep cerebellar nuclei or supratentorial areas. The presenting symptoms and the majority of imaging findings resolved on follow up MRI.. To our knowledge, Minnelide has shown an uncommon radiologic pattern of isolated cerebellar cortical involvement compared to other causes of cerebellar toxicity. Since this is a new medication, physicians' familiarity with the presenting symptoms and its temporal association with the imaging findings is important.

Topics: Cerebellum; Clinical Trials, Phase I as Topic; Colonic Neoplasms; Diterpenes; Epoxy Compounds; Fatal Outcome; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Organophosphates; Pancreatic Neoplasms; Phenanthrenes

Triptolide (TP) shows strong anti-tumor activities on various cancer cells, especially on pancreatic cancer. TP inhibits HSP70 expression leading to cell death in pancreatic cancer cells and induces cell death by apoptotic and autophagic pathways. In order to increase the therapeutic index of TP, a novel intravenous TP-loaded delivery system, TP-loaded lipid emulsion (TP-LE), has been developed to treat solid tumor. In the present study, the preparation and characterization of TP-LE were described. The pharmacokinetics and tissue distribution study of TP-LE in mice were also evaluated. Results demonstrated that TP-LE had an average particle size of 154.6 nm, entrapment efficiency (EE%) of 87%, zeta potential of -0.903 mV and autoclaved stability. The pharmacokinetic study showed that blood concentrations of both TP-LE and TP reached a maximum at the end of intravenous administration (1.25 mg/kg) and declined rapidly within the first 10 min with a mean residence time (MRT) of about 10 min. In the tissue distribution study, a preferential accumulation and longer residence time of drug in pancreas were found in TP-LE. The AUC0-60min of TP-LE in pancreas was 2.19 times in comparison to free TP, suggesting that the use of TP-LE conferred improvements in biodistribution, accumulation and therapeutic efficacy in pancreas. Moreover, the concentrations of TP-LE in heart, lung and kidney were lower than that of the TP group, indicating the potential for reduced toxicity of TP-LE. Together, all the results show that TP-LE appears to be a promising formulation for using TP in treating cancer, and more specifically pancreatic cancer.

Topics: Animals; Chemistry, Pharmaceutical; Diterpenes; Drug Carriers; Drug Delivery Systems; Epoxy Compounds; Female; Humans; Lipids; Mice; Pancreas; Pancreatic Neoplasms; Phenanthrenes; Tissue Distribution

Pancreatic cancer stromal microenvironment is considered to be the major reason for failure of conventional and targeted therapy for this disease. The desmoplastic stroma, comprising mainly collagen and glycosaminoglycans like hyaluronan (HA), is responsible for compression of vasculature in the tumor resulting in impaired drug delivery and poor prognosis. Minnelide, a water-soluble prodrug of triptolide currently in phase I clinical trial, has been very effective in multiple animal models of pancreatic cancer. However, whether Minnelide will have efficacious delivery into the tumor despite the desmoplastic stroma has not been evaluated before.. Patient tumor-derived xenografts (PDX) and spontaneous pancreatic cancer mice were treated with 0.42 and 0.21 mg/kg body weight for 30 days. Stromal components were determined by IHC and ELISA-based assays. Vascular functionality and drug delivery to the tumor were assessed following treatment with Minnelide.. Our current study shows that treatment with Minnelide resulted in reduction of ECM components like HA and collagen in the pancreatic cancer stroma of both the spontaneous KPC mice as well as in patient tumor xenografts. Furthermore, treatment with Minnelide improved functional vasculature in the tumors resulting in four times more functional vessels in the treated animals compared with untreated animals. Consistent with this observation, Minnelide also resulted in increased drug delivery into the tumor compared with untreated animals. Along with this, Minnelide also decreased viability of the stromal cells along with the tumor cells in pancreatic adenocarcinoma.. In conclusion, these results are extremely promising as they indicate that Minnelide, along with having anticancer effects is also able to deplete stroma in pancreatic tumors, which makes it an effective therapy for pancreatic cancer.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Survival; Diterpenes; Drug Delivery Systems; Epoxy Compounds; Humans; Mice; Mice, Inbred NOD; Mice, SCID; Organophosphates; Pancreatic Neoplasms; Phenanthrenes; Stromal Cells; Tumor Microenvironment

Oxaliplatin is part of pancreatic cancer therapy in the FOLFIRINOX or GEMOX/XELOX regimen. DNA damage repair is one of the factors responsible for oxaliplatin resistance that eventually develops in this cancer. Triptolide/Minnelide has been shown to be effective against pancreatic cancer in preclinical trials. In this study, we evaluated the efficacy of combination of triptolide and oxaliplatin against pancreatic cancer.. Highly aggressive pancreatic cancer cells (MIA PaCa-2 and PANC-1) were treated with oxaliplatin (0-10 μM), low-dose triptolide (50 nM), or a combination of both for 24-48 h. Cell viability, apoptosis, and DNA damage were evaluated by appropriate methods. Nucleotide excision repair pathway components were quantitated using qPCR and Western blot. Combination of low doses of Minnelide and oxaliplatin was tested in an orthotopic murine model of pancreatic cancer.. Proliferation of pancreatic cancer cells was markedly inhibited by combination treatment. Triptolide potentiated apoptotic cell death induced by oxaliplatin and sensitized cancer cells towards oxaliplatin-induced DNA damage by suppressing the oxaliplatin-induced DNA damage repair pathway. Combination of low doses of Minnelide and oxaliplatin inhibited tumor progression by inducing significant apoptotic cell death in these tumors.. Combination of low doses of Minnelide and oxaliplatin has immense potential to emerge as a novel therapeutic strategy against pancreatic cancer.

Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Line, Tumor; Cell Survival; Diterpenes; DNA Damage; DNA Repair; Down-Regulation; Epoxy Compounds; Female; Humans; Mice; Organophosphates; Organoplatinum Compounds; Oxaliplatin; Pancreatic Neoplasms; Phenanthrenes; Random Allocation

A valid preclinical tumor model should recapitulate the tumor microenvironment. Immune and stromal components are absent in immunodeficient models of pancreatic cancer. While these components are present in genetically engineered models such as Kras(G12D); Trp53(R172H); Pdx-1Cre (KPC), immense variability in development of invasive disease makes them unsuitable for evaluation of novel therapies. We have generated a novel mouse model of pancreatic cancer by implanting tumor fragments from KPC mice into the pancreas of wild type mice. Three-millimeter tumor pieces from KPC mice were implanted into the pancreas of C57BL/6J mice. Four to eight weeks later, tumors were harvested, and stromal and immune components were evaluated. The efficacy of Minnelide, a novel compound which has been shown to be effective against pancreatic cancer in a number of preclinical murine models, was evaluated. In our model, consistent tumor growth and metastases were observed. Tumors demonstrated intense desmoplasia and leukocytic infiltration which was comparable to that in the genetically engineered KPC model and significantly more than that observed in KPC tumor-derived cell line implantation model. Minnelide treatment resulted in a significant decrease in the tumor weight and volume. This novel model demonstrates a consistent growth rate and tumor-associated mortality and recapitulates the tumor microenvironment. This convenient model is a valuable tool to evaluate novel therapies.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Diterpenes; Epoxy Compounds; Female; Mice; Mice, Inbred C57BL; Mice, Transgenic; Neoplasms, Experimental; Organophosphates; Pancreatic Neoplasms; Phenanthrenes; Random Allocation; Tumor Microenvironment

Chemoresistance is the major impediment for treating pancreatic cancer. Herb-derived compound triptolide (TP) can inhibit proliferation of chemo-resistant pancreatic cancer (CPC) cell lines through multiple mechanisms, which exhibited superior anticancer efficacy compared with gemcitabine. However, toxicity due to non-specific exposure to healthy tissues hindered its clinical translation. Herein we successfully achieved targeting CPC cells and avoiding exposure to healthy tissues for TP by nucleolin-specific aptamer (AS1411) mediated polymeric nanocarrier. We conjugated AS1411 aptamer to carboxy terminated poly(ethylene glycol)-block-poly(d, l-lactide) (HOOC-PEG-PDLLA), then prepared AS1411-PEG-PDLLA micelle loading TP (AS-PPT) through solid dispersion technique. AS-PPT showed more antitumor activity than TP and equivalent specific binding ability with gemcitabine-resistant human pancreatic cancer cell (MIA PaCa-2) to AS1411 aptamer in vitro. Furthermore, we studied the distribution of AS-PPT (Cy3-labed TP) at tissue and cellular levels using biophotonic imaging technology. The results showed AS1411 facilitated TP selectively accumulating in tumor tissues and targeting CPC cells. The lifetime of the MIA PaCa-2 cell-bearing mice administrated with AS-PPT was efficiently prolonged than that of the mice subjected to the clinical anticancer drug Gemzar® in vivo. Such work provides a new strategy for overcoming the drug resistance of pancreatic cancer.

Topics: Animals; Antimetabolites, Antineoplastic; Antineoplastic Agents, Alkylating; Aptamers, Nucleotide; Deoxycytidine; Diterpenes; Drug Resistance, Neoplasm; Epoxy Compounds; Female; Gemcitabine; Humans; Immunoenzyme Techniques; Mice; Mice, Inbred BALB C; Mice, Nude; Nanomedicine; Oligodeoxyribonucleotides; Pancreatic Neoplasms; Phenanthrenes; Polyethylene Glycols; Polymers; Tissue Distribution; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Even when diagnosed prior to metastasis, pancreatic ductal adenocarcinoma (PDAC) is a devastating malignancy with almost 90% lethality, emphasizing the need for new therapies optimally targeting the tumors of individual patients.. We first developed a panel of new physiologic models for study of PDAC, expanding surgical PDAC tumor samples in culture using short-term culture and conditional reprogramming with the Rho kinase inhibitor Y-27632, and creating matched patient-derived xenografts (PDX). These were evaluated for sensitivity to a large panel of clinical agents, and promising leads further evaluated mechanistically.. Only a small minority of tested agents was cytotoxic in minimally passaged PDAC cultures in vitro Drugs interfering with protein turnover and transcription were among most cytotoxic. Among transcriptional repressors, triptolide, a covalent inhibitor of ERCC3, was most consistently effective in vitro and in vivo causing prolonged complete regression in multiple PDX models resistant to standard PDAC therapies. Importantly, triptolide showed superior activity in MYC-amplified PDX models and elicited rapid and profound depletion of the oncoprotein MYC, a transcriptional regulator. Expression of ERCC3 and MYC was interdependent in PDACs, and acquired resistance to triptolide depended on elevated ERCC3 and MYC expression. The Cancer Genome Atlas analysis indicates ERCC3 expression predicts poor prognosis, particularly in CDKN2A-null, highly proliferative tumors.. This provides initial preclinical evidence for an essential role of MYC-ERCC3 interactions in PDAC, and suggests a new mechanistic approach for disruption of critical survival signaling in MYC-dependent cancers. Clin Cancer Res; 22(24); 6153-63. ©2016 AACR.

Topics: Amides; Animals; Carcinoma, Pancreatic Ductal; Cell Line; Cell Line, Tumor; Cell Proliferation; Diterpenes; DNA Helicases; DNA-Binding Proteins; Epoxy Compounds; Gene Expression Regulation, Neoplastic; Heterografts; Humans; Mice; Mice, SCID; NIH 3T3 Cells; Pancreatic Neoplasms; Phenanthrenes; Proto-Oncogene Proteins c-myc; Pyridines; rho-Associated Kinases; Signal Transduction; Transcription, Genetic

Hypoxia is widely present in pancreatic cancer and subsequently causes the overexpression of hypoxia-inducible factor-1α (HIF-1α) and signal transducer and activator of transcription-3 (Stat3). HIF-1α and Stat3 function cooperatively to regulate a number of downstream genes that are implicated in tumorigenesis. Thus, inhibition of HIF-1α and Stat3 is a potential therapeutic strategy for pancreatic cancer. In this study, we explored how LB-1, a novel triptolide (LA) derivative, exerted its antitumor effect through blockade of HIF-1α and Stat3 signaling. Our data showed that LB-1 was able to inhibit the proliferation and colony formation of Mia-PaCa2 and SW1990 cells. LB-1 suppressed HIF-1α protein accumulation by promoting its proteasome degradation and reducing transactivation. Moreover, the silence of HIF-1α by shRNA partially prevented the proliferation inhibition triggered by LB-1. As expected, LB-1 also decreased Stat3 protein accumulation and blocked the physical interactions between HIF-1α/p300/phosphor-Stat3 (p-Stat3) at the pharmacological concentration to reduce VEGF expression, thereby hypoxia-induced angiogenesis. In the Mia-PaCa2 nude xenograft model, therapeutic treatment with LB-1 significantly inhibited tumor growth and had minimal systemic toxicity compared to the mother drug LA. Furthermore, in accordance with in vitro results, HIF-1α activation and Stat3 expression in tumors were blocked by LB-1 through mTOR-dependent pathway. Taken together, these results illustrate that, as a potent inhibitor of HIF-1α and Stat3 signaling, LB-1 exhibits antitumor effect and could be potentially used to treat pancreatic cancer.

Topics: Cell Hypoxia; Cell Line, Tumor; Diterpenes; Epoxy Compounds; Gene Expression Regulation, Neoplastic; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Neovascularization, Pathologic; Pancreatic Neoplasms; Phenanthrenes; Promoter Regions, Genetic; Signal Transduction; STAT3 Transcription Factor; TOR Serine-Threonine Kinases

Pancreatic cancer has a 5-year survival rate of less than 5%, partly because of limited chemotherapeutic options, thereby highlighting the need for novel therapies. Triptolide, a diterpene triepoxide that was derived from a Chinese herb, has shown great promise in preclinical testing against pancreatic cancer using immunocompromised animals.. In this study, we tested the ability of triptolide to induce cell death in cell lines derived from a primary tumor and adjacent liver metastases of immunocompetent animals (Kras, Trp53, Pdx-1 Cre [KPC]). Both cell lines were more aggressive in their ability to form tumors when compared with other pancreatic cancer cell lines and showed constitutive activation of the nuclear factor κ-light-chain-enhancer of activated B cells pathway. Triptolide induced apoptotic cell death in both cell lines, as evidenced by decreased cell viability as well as increased caspase 3/7 activity, annexin V positivity, and increased terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling positivity in tumors from KPC animals treated with Minnelide. In addition, triptolide decreased levels of HSP70, its transcription factor HSF1, as well as the antiapoptotic proteins Bcl-xL, Bcl-2, and Mcl-1, which are known to be up-regulated in pancreatic cancer.. The ability of triptolide to cause cell death in cell lines derived from immunocompetent animals further validates its potential as a novel agent against pancreatic cancer.

Topics: Animals; Antineoplastic Agents, Alkylating; Apoptosis; Biomarkers, Tumor; Cell Line, Tumor; Diterpenes; Epoxy Compounds; Immunocompetence; Mice; Mice, Transgenic; Pancreatic Neoplasms; Phenanthrenes

Triptolide (TL) is known to suppress the proliferation of a number of pancreatic cancer cell lines in vitro. Marked antitumor effects were also observed in a xenograft model of pancreatic cancer. Hypoxia‑inducible factor‑1α (HIF‑1α) is highly expressed in pancreatic cancer cells lines. The present study therefore tested the hypothesis that suppression of HIF‑1α is associated with the antitumor activity of TL. Quantitative polymerase chain reaction and western blot analysis were used to determine the level of gene expression. A xenograft tumor model of pancreatic cancer was established in athymic nude mice and the tumor size was measured to evaluate the outcome of TL treatment. Immunohistochemistry was used to detect the expression of HIF‑1α and vascular endothelial growth factor (VEGF), and to assess microvessel density. Microarray was used to investigate gene expression in pancreatic cancer cells following TL treatment. The expression of HIF‑1α was shown to be reduced in pancreatic cell lines following treatment with TL, and this effect occurred in a dose‑dependent manner. In a xenograft model of pancreatic cancer, reduced levels of HIF‑1α were also observed in mice that were treated with TL. Furthermore, the expression of VEGF, which is a direct target of HIF‑1α, was also suppressed, and the microvessel density of tumor tissues was consequently reduced. A microarray analysis of gene expression was performed in order to investigate the potential mechanisms underlying the antitumor activity of TL. The results showed that 11 genes, including c‑Myc, SOX9 and Ets2, were downregulated at an early stage following treatment with TL. A recent study indicated that overexpression of c‑Myc in colon cancer cells promotes increased expression of HIF‑1α and VEGF. Therefore, TL may suppress HIF‑1α through a c‑Myc‑dependent mechanism, which is involved in antitumor effects in mouse models of pancreatic cancer.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Diterpenes; Epoxy Compounds; Female; Gene Expression; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Mice, Inbred BALB C; Mice, Nude; Pancreatic Neoplasms; Phenanthrenes; Proto-Oncogene Proteins c-myc; Signal Transduction; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

Pancreatic cancer remains a challenging disease worldwide. Cryptotanshinone (CPT) is one of the active constituents of Salvia miltiorrhiza Bunge and exhibits significant antitumor activities in several human cancer cells. However, the efficacy and molecular mechanism of CPT in pancreatic cancer remains to be elucidated. In the present study, the effect of CPT on the proliferation, apoptosis and cell cycle of human pancreatic cancer cell BxPC‑3 cells was evaluated. The results demonstrated that CPT inhibited proliferation of the BxPC‑3 cells in a concentration‑dependent manner, and significantly induced cell apoptosis and cell cycle arrest. The protein levels of cleaved caspase‑3, caspase‑9 and poly ADP ribose polymerase were upregulated, while the levels of c‑myc, survivin and cyclin D1 were downregulated following treatment with CPT. In addition, CPT decreased the activities of signal transducer and activator of transcription 3 (STAT3) and several upstream regulatory signaling pathways after 24 h. However, CPT only inhibited the phosphorylation of STAT3 Tyr705 within 30 min, without marked effects on the phosphorylation of the other proteins. These results suggested that the inhibition of STAT3 activity by CPT was directly and independent of the upstream regulators in human pancreatic cancer. The present study demonstrated that CPT exerts anticancer effects by inducing apoptosis and cell cycle arrest via inhibition of the STAT3 signaling pathway in human BxPC-3 cells.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Caspase 3; Caspase 9; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Humans; Pancreas; Pancreatic Neoplasms; Phenanthrenes; Salvia miltiorrhiza; Signal Transduction; STAT3 Transcription Factor

Pancreatic Ductal Adenocarcinoma (PDAC) is a devastating disease hallmarked by limited patient survival. Resistance to chemotherapy, a major cause of treatment failure in PDAC patients, is often attributed to Cancer Stem Cells (CSCs). Pancreatic CSCs are a small subset of quiescent cells within a tumor represented by surface markers like CD133. These cells are responsible not only for tumor recurrence, but also poor prognosis based on their "stem-like" characteristics. At present, conventional therapy is directed towards rapidly dividing PDAC cells and thus fails to target the CSC population.. MIA PaCa-2, S2-013 and AsPC-1 were treated with 12.5 nM triptolide (12 T cells) for 7 days. The surviving cells were recovered briefly in drug-free growth media and then transferred to Cancer Stem cell Media (CSM). As a control, untreated cells were also transferred to CSM media (CSM). The 12 T and CSM cells were tested for stemness properties using RNA and protein markers. Low numbers of CSM and 12 T cells were implanted subcutaneously in athymic nude mice to study their tumorigenic potential. 12 T and CSM cells were sorted for CD133 expression and assayed for their colony forming ability and sphere forming ability. Invasiveness of 12 T cells, CSM and MIA PaCa-2 were compared using Boyden chamber assays.. Treated 12 T cells displayed increased expression of the surface marker CD133 and the drug transporter ABCG2 compared to untreated cells (CSM cells). Both 12 T and CSM cells formed subcutaneous tumors in mice confirming their tumor-initiating properties. When tested for invasion, 12 T cells had increased invasiveness compared to CSM cells. CD133(+) cells in both CSM and 12 T showed greater colony and sphere forming ability compared to CD133(-) cells from each group. Consistent with these data, when injected subcutaneously in mice, CD133(-) cells from CSM or 12 T did not form any tumors whereas CD133(+) cells from both groups showed tumor formation at a very low cell number. Despite pre-exposure to triptolide in 12 T CD133(+) cells, treatment of tumors formed by these cells with Minnelide, a triptolide pro-drug, showed significant tumor regression.. Our results indicated that triptolide enhanced and enriched the "stemness" in the PDAC cell lines at a low dose of 12.5 nM, but also resulted in the regression of tumors derived from these cells.

Topics: AC133 Antigen; Antigens, CD; Antineoplastic Agents; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cell Survival; Diterpenes; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Epoxy Compounds; Glycoproteins; Humans; Neoplastic Stem Cells; Organophosphates; Pancreatic Neoplasms; Peptides; Phenanthrenes; Side-Population Cells

Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal malignancies characterized by an intense tumor stroma with hypoperfused regions, a significant inflammatory response and pronounced therapy resistance. New therapeutic agents are urgently needed. The plant-derived agent triptolide also known as "thunder god vine" has a long history in traditional Chinese medicine for treatment of rheumatoid arthritis and cancer and is now in a clinical phase II trial for establishing the efficacy against a placebo. The authors mimicked the situation in patient tumors by induction of hypoxia in experimental models of pancreatic cancer stem cells (CSCs) and evaluated the therapeutic effect of triptolide. Hypoxia led to induction of colony and spheroid formation, aldehyde dehydrogenase 1 (ALDH1) and NF-κB activity, migratory potential and a switch in morphology to a fibroblastoid phenotype, as well as stem cell- and epithelial-mesenchymal transition-associated protein expression. Triptolide efficiently inhibited hypoxia-induced transcriptional signaling and downregulated epithelial-mesenchymal transition (EMT) and CSC features in established highly malignant cell lines, whereas sensitive cancer cells or nonmalignant cells were less affected. In vivo triptolide inhibited tumor take and tumor growth. In primary CSCs isolated from patient tumors, triptolide downregulated markers of CSCs, proliferation and mesenchymal cells along with upregulation of markers for apoptosis and epithelial cells. This study is the first to show that triptolide reverses EMT and CSC characteristics and therefore may be superior to current chemotherapeutics for treatment of PDA.

Topics: Aldehyde Dehydrogenase 1 Family; Animals; Antineoplastic Agents, Alkylating; Biomarkers, Tumor; Blotting, Western; Carcinoma, Pancreatic Ductal; Cell Hypoxia; Cell Line, Tumor; Cell Movement; Chick Embryo; Diterpenes; Down-Regulation; Epithelial-Mesenchymal Transition; Epoxy Compounds; Humans; Isoenzymes; Mice; Mice, Inbred Strains; Mice, Nude; Neoplastic Stem Cells; NF-kappa B; Pancreatic Neoplasms; Phenanthrenes; Proto-Oncogene Proteins c-rel; Retinal Dehydrogenase; RNA Interference; Spheroids, Cellular; Xenograft Model Antitumor Assays

Pancreatic adenocarcinoma is the fourth leading cause for cancer-related mortality with a survival rate of less than 5%. Late diagnosis and lack of effective chemotherapeutic regimen contribute to these grim survival statistics. Relapse of any tumor is largely attributed to the presence of tumor-initiating cells (TIC) or cancer stem cells (CSC). These cells are considered as hurdles to cancer therapy as no known chemotherapeutic compound is reported to target them. Thus, there is an urgent need to develop a TIC-targeted therapy for pancreatic cancer.. We isolated CD133(+) cells from a spontaneous pancreatic ductal adenocarcinoma mouse model and studied both surface expression, molecular markers of pancreatic TICs. We also studied tumor initiation properties by implanting low numbers of CD133(+) cells in immune competent mice. Effect of Minnelide, a drug currently under phase I clinical trial, was studied on the tumors derived from the CD133(+) cells.. Our study showed for the first time that CD133(+) population demonstrated all the molecular markers for pancreatic TIC. These cells initiated tumors in immunocompetent mouse models and showed increased expression of prosurvival and proinvasive proteins compared to the CD133(-) non-TIC population. Our study further showed that Minnelide was very efficient in downregulating both CD133(-) and CD133(+) population in the tumors, resulting in a 60% decrease in tumor volume compared with the untreated ones.. As Minnelide is currently under phase I clinical trial, its evaluation in reducing tumor burden by decreasing TIC as well as non-TIC population suggests its potential as an effective therapy.

Topics: AC133 Antigen; Animals; Antigens, CD; Antigens, Surface; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Cell Transformation, Neoplastic; Disease Models, Animal; Diterpenes; Epoxy Compounds; Gene Expression; Glycoproteins; Immunophenotyping; Mice; Mice, Transgenic; Neoplastic Stem Cells; NF-kappa B; Organophosphates; Pancreatic Neoplasms; Peptides; Phenanthrenes; Phenotype

The tumor necrosis factor related apoptosis-inducing ligand (TRAIL) causes cancer cell death, but many cancers, including pancreatic cancer, are resistant to TRAIL therapy. A combination of TRAIL and the diterpene triepoxide, triptolide, is effective in inducing pancreatic cancer cell death. Triptolide increases levels of death receptor DR5 and decreases the pro-survival FLICE-like inhibitory protein (c-FLIP), which contribute to the activation of caspase-8. This combination further causes both lysosomal and mitochondrial membrane permeabilization, resulting in cell death. Our study provides a mechanism by which triptolide sensitizes TRAIL resistant cells, which may become a novel therapeutic strategy against pancreatic cancer.

Topics: Animals; Antineoplastic Agents, Alkylating; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; bcl-2-Associated X Protein; BH3 Interacting Domain Death Agonist Protein; CASP8 and FADD-Like Apoptosis Regulating Protein; Caspase 8; Cell Line, Tumor; Cell Survival; Diterpenes; Drug Resistance, Neoplasm; Enzyme Activation; Epoxy Compounds; Humans; Lysosomes; Mice; Mitochondrial Membranes; Pancreatic Neoplasms; Permeability; Phenanthrenes; Receptors, TNF-Related Apoptosis-Inducing Ligand; RNA Interference; Signal Transduction; TNF-Related Apoptosis-Inducing Ligand; Transfection

Pancreatic cancer is a devastating disease with a survival rate of <5%. Moreover, pancreatic cancer aggressiveness is closely related to high levels of prosurvival mediators, which can ultimately lead to rapid disease progression. One of the mechanisms that enables tumor cells to evade cellular stress and promote unhindered proliferation is the endoplasmic reticulum (ER) stress response. Disturbances in the normal functions of the ER lead to an evolutionarily conserved cell stress response, the unfolded protein response (UPR). The UPR initially compensates for damage, but it eventually triggers cell death if ER dysfunction is severe or prolonged. Triptolide, a diterpene triepoxide, has been shown to be an effective compound against pancreatic cancer. Our results show that triptolide induces the UPR by activating the PKR-like ER kinase-eukaryotic initiation factor 2α axis and the inositol-requiring enzyme 1α-X-box-binding protein 1 axis of the UPR and leads to chronic ER stress in pancreatic cancer. Our results further show that glucose-regulated protein 78 (GRP78), one of the major regulators of ER stress, is downregulated by triptolide, leading to cell death by apoptosis in MIA PaCa-2 cells and autophagy in S2-VP10 cells.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Apoptosis Regulatory Proteins; Beclin-1; Cell Line, Tumor; Chronic Disease; Diterpenes; DNA-Binding Proteins; Down-Regulation; Endoplasmic Reticulum; Endoplasmic Reticulum Chaperone BiP; Epoxy Compounds; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Gene Silencing; Heat-Shock Proteins; Membrane Proteins; Pancreatic Neoplasms; Phenanthrenes; Regulatory Factor X Transcription Factors; Stress, Physiological; Transcription Factors; Unfolded Protein Response

Transplantation of tumor xenografts to fertilized chicken eggs is a promising animal replacement method, which has successfully been used for xenotransplantation of pancreatic ductal adenocarcinoma (PDA) cells. PDA is characterized by a pronounced tumor hypoxia, which mediates aggressive growth, therapy resistance and cancer stem cell (CSC) features. For in vivo experimental evaluation of hypoxia-targeting therapeutic strategies, the xenografting of tumors to chicken eggs combined with the induction of hypoxia is necessary. However, the chicken embryos do not survive the conventional method of hypoxia induction by a gas mixture of 1% O2, 5% CO2, 94% N2, not even when hypoxia is applied for only 30 min. Therefore, we employed chemical induction of hypoxia by the hypoxia mimetic agent cobalt chloride (CoCl2). Whereas CoCl2 did not further increase tumor growth, it mediated the induction of carbonic anhydrase IX (CAIX) in the tumor xenografts and led to enhanced expression of the human CSC markers CD133, Sox2 and CD44. Side-effects in chicken embryos were not observed as evaluated by H&E staining of embryo-derived liver sections and the determination of the embryo weight. These results suggest the successful induction of hypoxia in chicken eggs and xenografted tumors by CoCl2. For therapeutic intervention and as a control, we treated the eggs with the plant-derived anti-inflammatory agent triptolide, which recently showed promising effects toward hypoxia-induced tumor progression in experimental PDA. Triptolide abolished tumor growth and the CoCl2-induced hypoxic effects, without inducing obvious side-effects. Collectively, our data present a new in vivo animal replacement method for the successful induction of tumor hypoxia in PDA.

Topics: Animals; Antineoplastic Agents, Alkylating; Biomarkers, Tumor; Carbonic Anhydrases; Carcinoma, Pancreatic Ductal; Cell Hypoxia; Chick Embryo; Cobalt; Diterpenes; Epoxy Compounds; Gene Expression Regulation, Neoplastic; Humans; Neoplasms, Experimental; Neoplastic Stem Cells; Pancreatic Neoplasms; Phenanthrenes

Pancreatic ductal adenocarcinoma (PDAC), one of the deadliest malignancies, is resistant to current chemotherapies. We previously showed that triptolide inhibits PDAC cell growth in vitro and blocks metastatic spread in vivo. Triptolide downregulates HSP70, a molecular chaperone upregulated in several tumor types. This study investigates the mechanism by which triptolide inhibits HSP70. Because microRNAs (miRNA) are becoming increasingly recognized as negative regulators of gene expression, we tested whether triptolide regulates HSP70 via miRNAs. Here, we show that triptolide as well as quercetin, but not gemcitabine, upregulated miR-142-3p in PDAC cells (MIA PaCa-2, Capan-1, and S2-013). Ectopic expression of miR-142-3p inhibited cell proliferation, measured by electric cell-substrate impedance sensing, and decreased HSP70 expression, measured by real-time PCR and immunoblotting, compared with controls. We showed that miR-142-3p directly binds to the 3'UTR of HSP70, and that this interaction is important as HSP70 overexpression rescued miR-142-3p-induced cell death. We found that miR-142-3p regulates HSP70 independently of heat shock factor 1. Furthermore, Minnelide, a water-soluble prodrug of triptolide, induced the expression of miR-142-3p in vivo. This is the first description of an miRNA-mediated mechanism of HSP70 regulation in cancer, making miR-142-3p an attractive target for PDAC therapeutic intervention.

Topics: Animals; Antineoplastic Agents, Alkylating; Apoptosis; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cell Proliferation; Diterpenes; Epoxy Compounds; Female; Gene Expression; HEK293 Cells; HSP70 Heat-Shock Proteins; Humans; Mice; Mice, SCID; MicroRNAs; Pancreatic Neoplasms; Phenanthrenes; Random Allocation; Transfection; Xenograft Model Antitumor Assays

Triptolide (TPL) inhibits the growth and proliferation of a wide range of human cancer cells, but the underlying mechanism is largely unknown. Here, we report that TPL induces apoptosis and inhibits proliferation of PANC-1 pancreatic cancer cells by downregulating cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF). Cell viability and apoptosis were measured by MTT assay and flow cytometry. Real-time PCR and Western blot were used to examine the expression of COX-2 and VEGF. The Matrigel angiogenesis and Transwell migration were employed to assess tube formation and cell migration. Pancreatic cancer mouse xenografts were established to investigate the in vivo antitumor effects of TPL. TUNEL staining and immunohistochemistry were used to detect the apoptosis rate and protein expression in tumor tissues. TPL inhibited the proliferation of pancreatic cancer cells in a time and concentration-dependent manner and decreased the expression of COX-2 and VEGF in vitro. Furthermore, medium from TPL-treated PANC-1 cells inhibited the proliferation, migration, and tube formation of HUVECs. TPL significantly reduced the growth of pancreatic cancer mouse xenografts, accompanied by an induction of apoptosis, inhibition of angiogenesis, and reduction of COX-2 and VEGF. Our data indicate that suppressing the expression of COX-2 and VEGF may be one of the molecular mechanisms by which TPL induces apoptosis and inhibits the growth and angiogenesis of human pancreatic cancer cells.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Diterpenes; Down-Regulation; Epoxy Compounds; Female; Humans; Male; Mice; Mice, Inbred BALB C; Neovascularization, Pathologic; Pancreatic Neoplasms; Phenanthrenes; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

Pancreatic cancer is one of the most lethal human malignancies, with an all-stage 5-year survival of <5%, mainly due to lack of effective available therapies. Cancer cell survival is dependent upon up-regulation of the pro-survival response, mediated by anti-apoptotic proteins such as Mcl-1.. Here we show that over-expression of Mcl-1 in pancreatic patient tumor samples is linked to advancement of the disease. We have previously shown that triptolide, a diterpene triepoxide, is effective both in vitro and in vivo, in killing pancreatic cancer cells. Decrease of Mcl-1 levels, either by siRNA or by treatment with triptolide results in cell death. Using pancreatic cancer cell lines, we have shown that miR-204, a putative regulator of Mcl-1, is repressed in cancer cell lines compared to normal cells. Over-expression of miR-204, either by a miR-204 mimic, or by triptolide treatment results in a decrease in Mcl-1 levels, and a subsequent decrease in cell viability. Using luciferase reporter assays, we confirmed the ability of miR-204 to down-regulate Mcl-1 by directly binding to the Mcl-1 3' UTR. Using human xenograft samples treated with Minnelide, a water soluble variant of triptolide, we have shown that miR-204 is up-regulated and Mcl-1 is down-regulated in treated vs. control tumors.. Triptolide mediated miR-204 increase causes pancreatic cancer cell death via loss of Mcl-1.

Topics: 3' Untranslated Regions; Animals; Antineoplastic Agents; Base Sequence; Binding Sites; Cell Death; Cell Line, Tumor; Diterpenes; Epithelium; Epoxy Compounds; Gene Expression Regulation, Neoplastic; Humans; Liver Neoplasms; Mice; Mice, SCID; MicroRNAs; Myeloid Cell Leukemia Sequence 1 Protein; Organophosphates; Pancreatic Ducts; Pancreatic Neoplasms; Phenanthrenes; RNA Interference; Up-Regulation; Xenograft Model Antitumor Assays

Pancreatic cancer, the fourth most prevalent cancer-related cause of death in the United States, is a disease with a dismal survival rate of 5% 5 years after diagnosis. One of the survival proteins responsible for its extraordinary ability to evade cell death is HSP70. A naturally derived compound, triptolide, and its water-soluble prodrug, Minnelide, down-regulate the expression of this protein in pancreatic cancer cells, thereby causing cell death. However, the mechanism of action of triptolide has not been elucidated. Our study shows that triptolide-induced down-regulation of HSP70 expression is associated with a decrease in glycosylation of the transcription factor Sp1. We further show that triptolide inhibits glycosylation of Sp1, inhibiting the hexosamine biosynthesis pathway, particularly the enzyme O-GlcNAc transferase. Inhibition of O-GlcNAc transferase prevents nuclear localization of Sp1 and affects its DNA binding activity. This in turn down-regulates prosurvival pathways like NF-κB, leading to inhibition of HSF1 and HSP70 and eventually to cell death. In this study, we evaluated the mechanism by which triptolide affects glycosylation of Sp1, which in turn affects downstream pathways controlling survival of pancreatic cancer cells.

Topics: Acetylglucosamine; Active Transport, Cell Nucleus; Antineoplastic Agents, Alkylating; Cell Death; Cell Line, Tumor; Cell Nucleus; Cell Survival; Diterpenes; DNA-Binding Proteins; Down-Regulation; Epoxy Compounds; Gene Expression Regulation, Neoplastic; Glycosylation; Heat Shock Transcription Factors; HSP70 Heat-Shock Proteins; Humans; N-Acetylglucosaminyltransferases; Neoplasm Proteins; NF-kappa B; Pancreatic Neoplasms; Phenanthrenes; Signal Transduction; Sp1 Transcription Factor; Transcription Factors

Triptolide, extracted from the herb Tripteryglum wilfordii Hook.f that has long been used as a natural medicine in China, has attracted much interest for its anti-cancer effects against some kinds of tumours in recent years. Artesunate, extracted from the Chinese herb Artemisia annua, has proven to be effective and safe as an anti-malarial drug that possesses anticancer potential. The present study attempted to clarify if triptolide enhances artesunate-induced cytotoxicity in pancreatic cancer cell lines in vitro and in vivo.. In vitro, to test synergic actions, cell viability and apoptosis were analyzed after treatment of pancreatic cancer cell lines with the two agents singly or in combination. The molecular mechanisms of apoptotic effects were also explored using qRT-PCR and Western blotting. In vivo, a tumor xenograft model was established in nude mice, for assessment of inhibitory effects of triptolide and artesunate.. We could show that the combination of triptolide and artesunate could inhibit pancreatic cancer cell line growth, and induce apoptosis, accompanied by expression of HSP 20 and HSP 27, indicating important roles in the synergic effects. Moreover, tumor growth was decreased with triptolide and artesunate synergy.. Our result indicated that triptolide and artesunate in combination at low concentrations can exert synergistic anti-tumor effects in pancreatic cancer cells with potential clinical applications.

Topics: Animals; Antimalarials; Antineoplastic Agents, Alkylating; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Artemisinins; Artesunate; Blotting, Western; Cell Proliferation; Diterpenes; Drug Synergism; Epoxy Compounds; HSP27 Heat-Shock Proteins; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Pancreatic Neoplasms; Phenanthrenes; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Pancreatic cancer has one of the highest fatality rates of all cancers, and new strategies or reagents to tackle this disease are needed. Triptolide (TL) is able to potently inhibit the growth of pancreatic tumor cells in vitro. On the other hand, blockage of 5-LOX pathway might be useful for treatment of pancreatic cancer. In the current study, we tested the effects of 5-LOX RNA interference and TL individually or in combination in suppressing human pancreatic tumor growth in xenograft mouse model.. 5-LOX short hairpin RNA (shRNA) vectors were developed and screened out for their efficacy in human pancreatic cancer cell line SW1990 in vitro. Their antitumor effects were also evaluated by measuring cell proliferation and apoptosis. An effective 5-LOX shRNA was given alone or in combination with TL to treat pancreatic tumor xenograft. Expression levels of 5-LOX and VEGF were measured with Western blotting and immunohistology.. Knocking down 5-LOX gene suppressed cancer cell growth in vitro and intra-tumoral delivering of 5-LOX shRNA inhibited growth of transplanted tumor in vivo. TL treatment induced tumor suppression and greatly enhanced antitumor effects of 5-LOX shRNA in the mouse model. 5-LOX RNA interference or TL treatment suppresses VEGF expression in tumor tissue, and combined treatment further reduces its expression.. Both treatments exerted antitumor effects in vivo, and combined use of the two approaches produced more powerful antitumor effects. Synergistic effects of combined treatment in VEGF expression may contribute to the mechanisms of the strong antitumor effects.

Topics: Animals; Antineoplastic Agents, Alkylating; Apoptosis; Arachidonate 5-Lipoxygenase; Cell Line, Tumor; Cell Proliferation; Diterpenes; Epoxy Compounds; Female; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Pancreatic Neoplasms; Phenanthrenes; RNA Interference; RNA, Small Interfering; Vascular Endothelial Growth Factors; Xenograft Model Antitumor Assays

Pim-3, a proto-oncogene with serine/threonine kinase activity, is aberrantly expressed in malignant lesions, but not in normal tissues, of endoderm-derived organs, including the pancreas, liver, colon, and stomach. Furthermore, the development of hepatocellular carcinoma is accelerated in mice expressing Pim-3 transgene selectively in the liver when these mice are treated with a hepatocarcinogen. These observations suggest that a chemical targeting Pim-3 kinase may be a novel type of anticancer drug. In the present study, we screened low molecular weight chemicals and observed that the phenanthrene derivative T26 potently inhibited Pim-3 and Pim-1, but only weakly inhibited Pim-2. Moreover, T26 markedly inhibited the in vitro growth of human pancreatic cancer cell lines by inducing apoptosis and G(2) /M arrest. The growth inhibitory effects of T26 were reversed by overexpression of Pim-3 cDNA in human pancreatic cancer cells, indicating that T26 acts primarily on Pim-3. Furthermore, T26 inhibited the growth of a human pancreatic cancer cell line in nude mice without causing apparent adverse effects when it was administered after tumor formation was evident. These observations imply that the chemical and its related compounds may be effective for the treatment of cancers in which there is aberrant Pim-3 expression.

Topics: Animals; Apoptosis; Blotting, Western; Cell Cycle; Cell Proliferation; Cyclic AMP-Dependent Protein Kinases; Fluorescent Antibody Technique; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Pancreatic Neoplasms; Phenanthrenes; Proto-Oncogene Mas; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-pim-1; Proto-Oncogene Proteins c-sis; RNA, Small Interfering; Tumor Cells, Cultured

Triptolide (TPL) is a diterpenoid triepoxide that effectively induces apoptosis in a wide variety of cancer cells. However, the detailed mechanism by which TPL activates caspase cascade remains elusive. This study aimed to examine the antitumor effects of TPL against pancreatic cancer and investigate the underlying mechanism.. Cell proliferation was evaluated by sulforhodamine B assay. The apoptosis was evaluated by caspase activity assay, Western blot and flow cytometry. DcR3 level was measured by ELISA. AsPC-1 xenografts were established to compare the in vivo antitumor effects of TPL and Gemcitabine.. TPL inhibited the proliferation and induced the apoptosis of pancreatic cancer cells in a dose- and time-dependent manner. TPL also inhibited DcR3 expression in a dose- and time-dependent manner. siRNA-mediated DcR3 knockdown sensitized pancreatic cancer cells to TPL-induced apoptosis. In vivo, DcR3 siRNA significantly enhanced TPL-induced apoptosis and tumor growth inhibition. Moreover, TPL showed less toxicity compared to Gemcitabine in mice model.. TPL induces the apoptosis of pancreatic cancer cells via the downregulation of DcR3 expression and has the potential as an effective agent against pancreatic cancer.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; Blotting, Western; Caspases; Cell Line, Tumor; Cell Survival; Diterpenes; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Epoxy Compounds; Flow Cytometry; Humans; Mice; Mice, Nude; Pancreatic Neoplasms; Phenanthrenes; Receptors, Tumor Necrosis Factor, Member 6b; RNA Interference; Time Factors; Tumor Burden; Xenograft Model Antitumor Assays

We aim to pharmacologically downregulate heat shock protein 27 (HSP27) through triptolide (TPL) to improve the drug sensitivity of pancreatic cancer to cisplatin (DDP).. In vitro, we assessed cell viability and apoptosis by the combination of TPL and DDP in gemcitabine-resistant human pancreatic carcinoma PANC-1 and MIA PaCa-2 cell lines and examined the effect of silencing HSP27 by a small interfering RNA on cytotoxicity induced by TPL or DDP. In vivo, we apply TPL with DDP in a xenograft model to test the synergic action.. Triptolide cooperates with DDP to decrease cell viability and to induce apoptosis via the mitochondrial pathway, which is accompanied by a sharp decline in HSP27. Knocking down endogenous HSP27 can sensitize cancer cells to cytotoxicity with TPL or DDP, indicating the critical role of HSP27 down-regulation in the synergic effect. Meanwhile, TPL acts in synergy with DDP to cause tumor regression in vivo.. The combined therapy of TPL and DDP triggers a synergic apoptosis via inhibiting HSP27 in human gemcitabine-resistant pancreatic carcinoma and has a strong potential to be developed into a new effective regimen for pancreatic cancer treatment.

Topics: Animals; Antimetabolites, Antineoplastic; Antineoplastic Agents, Alkylating; Apoptosis; Cell Line, Tumor; Cell Survival; Cisplatin; Deoxycytidine; Diterpenes; Down-Regulation; Drug Resistance, Neoplasm; Drug Synergism; Epoxy Compounds; Female; Gemcitabine; HSP27 Heat-Shock Proteins; Humans; Mice; Mice, Nude; Mitochondria; Neoplasm Transplantation; Pancreatic Neoplasms; Phenanthrenes; RNA, Small Interfering; Transfection

A new formulation of a natural product shows remarkable activity against pancreatic ductal adenocarcinoma across a number of preclinical model systems. These findings set the stage for a clinical trial.

Topics: Animals; Antineoplastic Agents, Alkylating; Carcinoma, Pancreatic Ductal; Clinical Trials as Topic; Diterpenes; Drug Evaluation, Preclinical; Epoxy Compounds; Humans; Medical Oncology; Medicine, Chinese Traditional; Organophosphates; Pancreatic Neoplasms; Phenanthrenes; Research Design; Translational Research, Biomedical

Pancreatic cancer is one of the most lethal human malignancies with an all-stage 5-year survival frequency of <5%, which highlights the urgent need for more effective therapeutic strategies. We have previously shown that triptolide, a diterpenoid, is effective against pancreatic cancer cells in vitro as well as in vivo. However, triptolide is poorly soluble in water, limiting its clinical use. We therefore synthesized a water-soluble analog of triptolide, named Minnelide. The efficacy of Minnelide was tested both in vitro and in multiple independent yet complementary in vivo models of pancreatic cancer: an orthotopic model of pancreatic cancer using human pancreatic cancer cell lines in athymic nude mice, a xenograft model where human pancreatic tumors were transplanted into severe combined immunodeficient mice, and a spontaneous pancreatic cancer mouse model (KRas(G12D); Trp53(R172H); Pdx-1Cre). In these multiple complementary models of pancreatic cancer, Minnelide was highly effective in reducing pancreatic tumor growth and spread, and improving survival. Together, our results suggest that Minnelide shows promise as a potent chemotherapeutic agent against pancreatic cancer, and support the evaluation of Minnelide in clinical trials against this deadly disease.

Topics: Animals; Antineoplastic Agents, Alkylating; Cell Line, Tumor; Cell Survival; Diterpenes; Drug Screening Assays, Antitumor; Epoxy Compounds; Female; Humans; Mice; Mice, Nude; Mice, SCID; Neoplasm Transplantation; Organophosphates; Pancreatic Neoplasms; Phenanthrenes; Phosphoric Monoester Hydrolases

Pancreatic cancer is a devastating disease characterized by low sensitivity to conventional chemotherapeutic treatment that has a poor prognosis. Therefore, novel effective chemotherapeutic regimens need to be developed. In this study, we analyzed the combined cytotoxic effect of triptolide and hydroxycamptothecin (HCPT) on pancreatic cancer cell line PANC-1 by using 3-(4.5-dimethylthiazol-2-yl)-5-(3-carboxy-methoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) and fluorescence- activated cell sorting (FACS) assays. Our results showed that the sensitivity of a combined therapy using triptolide and HCPT was higher than that of triptolide or HCPT alone and that activation of caspase-9/caspase-3 and inhibition of nuclear factor-kappaB (NF-κB) signaling pathway may contribute to the synergistic cytotoxic effect of this combination therapy. Therefore, our observations provided evidence supporting the clinical applications of the combination chemotherapy using triptolide and HCPT for treating pancreatic cancer.

Topics: Antineoplastic Agents, Phytogenic; Antineoplastic Combined Chemotherapy Protocols; Camptothecin; Caspase 3; Caspase 9; Cell Line, Tumor; Diterpenes; Drug Synergism; Epoxy Compounds; Humans; NF-kappa B; Pancreatic Neoplasms; Phenanthrenes; Phytotherapy; Plant Extracts; Signal Transduction; Tripterygium

An emerging therapy in oncology is the induction of apoptotic cell death through anti-death receptor therapy. However, pancreatic cancer is resistant to apoptosis including anti-death receptor therapy. We have previously described how triptolide decreases resistance to apoptosis in pancreatic cancer cells in vitro and in vivo. We hypothesized that triptolide decreases tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance in pancreatic cancer cells. The aim of this study was to evaluate the effects that combined therapy with TRAIL and triptolide have on different parameters of apoptosis.. Four different pancreatic cancer cell lines were exposed to triptolide, TRAIL, or a combination of both drugs. We assessed the effects that combined therapy with TRAIL and triptolide has on cell viability, apoptosis, caspase-3 and caspase-9 activities, and poly(ADP)-ribose polymerase cleavage.. Pancreatic cancer cells were resistant to TRAIL therapy; however, combined therapy with triptolide and TRAIL significantly decreased the cell viability in all the cell lines and increased apoptotic cell death as a result of caspase-3 and caspase-9 activation.. Pancreatic cancer is highly resistant to anti-death receptor therapy, but combined therapy with TRAIL and triptolide is an effective therapy that induces apoptotic cell death in pancreatic cancer cells.

Topics: Adenocarcinoma; Antineoplastic Agents, Alkylating; Apoptosis; Cell Line, Tumor; Cell Survival; Diterpenes; Epoxy Compounds; Humans; Pancreatic Neoplasms; Phenanthrenes; TNF-Related Apoptosis-Inducing Ligand

Pancreatic adenocarcinoma, among the most lethal human malignancies, is resistant to current chemotherapies. We previously showed that triptolide inhibits the growth of pancreatic cancer cells in vitro and prevents tumor growth in vivo. This study investigates the mechanism by which triptolide kills pancreatic cancer cells.. Cells were treated with triptolide and viability and caspase-3 activity were measured using colorimetric assays. Annexin V, propidium iodide, and acridine orange staining were measured by flow cytometry. Immunofluorescence was used to monitor the localization of cytochrome c and Light Chain 3 (LC3) proteins. Caspase-3, Atg5, and Beclin1 levels were down-regulated by exposing cells to their respective short interfering RNA.. We show that triptolide induces apoptosis in MiaPaCa-2, Capan-1, and BxPC-3 cells and induces autophagy in S2-013, S2-VP10, and Hs766T cells. Triptolide-induced autophagy has a pro-death effect, requires autophagy-specific genes, atg5 or beclin1, and is associated with the inactivation of the Protein kinase B (Akt)/mammalian target of Rapamycin/p70S6K pathway and the up-regulation of the Extracellular Signal-Related Kinase (ERK)1/2 pathway. Inhibition of autophagy in S2-013 and S2-VP10 cells results in cell death via the apoptotic pathway whereas inhibition of both autophagy and apoptosis rescues cell death.. This study shows that triptolide kills pancreatic cancer cells by 2 different pathways. It induces caspase-dependent apoptotic death in MiaPaCa-2, Capan-1, and BxPC-3, and induces caspase-independent autophagic death in metastatic cell lines S2-013, S2-VP10, and Hs766T, thereby making it an attractive chemotherapeutic agent against a broad spectrum of pancreatic cancers.

Topics: Antineoplastic Agents, Alkylating; Apoptosis; Apoptosis Regulatory Proteins; Autophagy; Autophagy-Related Protein 5; Beclin-1; Caspase 3; Cell Line, Tumor; Cell Survival; Diterpenes; Dose-Response Relationship, Drug; Epoxy Compounds; Humans; Intracellular Signaling Peptides and Proteins; Membrane Proteins; Microtubule-Associated Proteins; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Pancreatic Neoplasms; Phenanthrenes; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins c-akt; Ribosomal Protein S6 Kinases, 70-kDa; RNA Interference; Signal Transduction; Time Factors; TOR Serine-Threonine Kinases

Pancreatic cancer, the fourth leading cause of cancer-related death in the United States, is resistant to current chemotherapies. Therefore, identification of different pathways of cell death is important to develop novel therapeutics. Our previous study has shown that triptolide, a diterpene triepoxide, inhibits the growth of pancreatic cancer cells in vitro and prevents tumor growth in vivo. However, the mechanism by which triptolide kills pancreatic cancer cells was not known, hence, this study aimed at elucidating it. Our study reveals that triptolide kills diverse types of pancreatic cancer cells by two different pathways; it induces caspase-dependent apoptotic death in some cell lines and death via a caspase-independent autophagic pathway in the other cell lines tested. Triptolide-induced autophagy requires autophagy-specific genes, atg5 or beclin 1 and its inhibition results in cell death via the apoptotic pathway, whereas inhibition of both autophagy and apoptosis rescues triptolide-mediated cell death. Our study shows for the first time that induction of autophagy by triptolide has a pro-death role in pancreatic cancer cells. Since triptolide kills diverse pancreatic cancer cells by different mechanisms, it makes an attractive chemotherapeutic agent for future use against a broad spectrum of pancreatic cancers.

Topics: Antineoplastic Agents, Alkylating; Autophagy; Cell Death; Cell Line, Tumor; Diterpenes; Epoxy Compounds; Humans; Pancreatic Neoplasms; Phenanthrenes

Heat shock proteins (HSPs) are highly conserved and serve a multitude of functions that mediate cell survival. HSP70, the only inducible form of the 70-kilodalton subfamily of HSPs, is overexpressed in pancreatic cancer cells and has been shown to inhibit caspase-dependent apoptosis. We aimed to elucidate the mechanism by which HSP70 inhibits apoptosis in cancer cells.. HSP70 expression was down-regulated in cultured pancreatic cancer cells by exposure to quercetin, triptolide, or short interfering RNAs. Intracellular Ca2+, cytosolic cathepsin B activity, caspase-3 activity, cell viability, and lysosome integrity were measured using colorimetric assays. Immunofluorescence assays were used to localize cathepsin B and Lamp2. BAPTA-AM was used to chelate intracellular Ca2+.. Inhibition of HSP70 increased intracellular Ca2+ levels in pancreatic and colon cancer cell lines and led to loss of lysosome integrity in pancreatic cancer cells. The release of intracellular Ca2+ and lysosomal enzymes activated caspase-dependent apoptosis independently and simultaneously.. HSP70 inhibits apoptosis in cancer cells by 2 mechanisms: attenuation of cytosolic calcium and stabilization of lysosomes. HSP70-mediated cell survival might occur in other types of cancer cells.

Topics: Apoptosis; Calcium; Caspase 3; Cathepsin B; Cell Line, Tumor; Cytosol; Diterpenes; Epoxy Compounds; HSP70 Heat-Shock Proteins; Humans; Lysosomal-Associated Membrane Protein 2; Lysosomes; Pancreatic Neoplasms; Phenanthrenes; Quercetin; RNA, Small Interfering

Topics: Anti-Inflammatory Agents, Non-Steroidal; bcl-2-Associated X Protein; Cell Division; Diterpenes; Epoxy Compounds; Humans; Neoplasms; Pancreatic Neoplasms; Phenanthrenes; Up-Regulation

Human pancreatic carcinoma is a highly malignant cancer. Previous studies have shown that the decoy receptor 3 (DcR3) for Fas ligand (FasL) plays significant roles in tumour progression and immune suppression. In the present study, we evaluated the anti-cancer activity of a natural compound, denbinobin (5-hydroxy-3,7-dimethoxy-1,4-phenanthraquinone), through decreasing DcR3 levels in human pancreatic adenocarcinoma cell lines.. We used immunoprecipitation and ELISA assays to examine DcR3 levels, and used FACS to determine the percentage of cells with a sub-G1 DNA content.. AsPC-1 and BxPC-3 human pancreatic cancer cells express high levels of DcR3. Denbinobin concentration-dependently decreased DcR3 levels in BxPC-3 cells. MTT and flow cytometry assays indicated that BxPC-3 was FasL-resistant because high concentrations (100 ng.mL(-1)) of soluble FasL did not inhibit cell growth. However, combinations of denbinobin (3 micromol.L(-1)) with lower concentrations of soluble FasL (10, 30 and 50 ng.mL(-1)) or membrane-bound FasL, were synergistic on cell growth inhibition and apoptosis. Exogenous excess DcR3 reversed this synergistic effect. We observed no significant increase in the levels of surface Fas, cleaved forms of caspase-8, -3, -9, Bax, Bid, Bcl-xL, cytochrome c or mitochondrial membrane potentials following denbinobin treatment. However, denbinobin treatment increased the levels of apoptosis-inducing factor.. Denbinobin and FasL trigger a synergistic cytotoxic effect in human pancreatic adenocarcinoma cells. Denbinobin mediated a decrease in levels of DcR3, which played a major role in this synergistic effect, and also increased caspase-independent apoptosis, via apoptosis-inducing factor.

Topics: Adenocarcinoma; Anthraquinones; Antineoplastic Agents, Phytogenic; Apoptosis; Apoptosis Inducing Factor; Cell Line, Tumor; Cell Survival; Drug Synergism; Fas Ligand Protein; Humans; Pancreatic Neoplasms; Phenanthrenes; Receptors, Tumor Necrosis Factor, Member 6b

The bane of anti-cancer therapy is usually the development of resistance to apoptosis in malignant cells. Identification of strategies to re-sensitize cancer cells to apoptosis has now become a top priority in anti-cancer research. Denbinobin is a novel, naturally occurring phenathroquinone isolated from orchids of the genus Dendrobium that has remarkable anti-cancer activities demonstrated both in vitro and in vivo. Recently denbinobin has been shown to diminish the levels of expression of the decoy receptor-3 and also to act synergistically with Fas ligand to induce apoptosis in a pancreatic adenocarcinoma cell line. There is hope that denbinobin could be developed as an adjuvant in combination therapies aimed at killing cancers that rely on decoy receptors to evade the host's immune surveillance.

Topics: Adenocarcinoma; Anthraquinones; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Line, Tumor; Drug Synergism; Fas Ligand Protein; Humans; Pancreatic Neoplasms; Phenanthrenes; Receptors, Tumor Necrosis Factor, Member 6b; Tumor Escape

To investigate apoptosis in human pancreatic cancer cells induced by Triptolide (TL), and the relationship between this apoptosis and expression of caspase-3' bcl-2 and bax.. Human pancreatic cancer cell line SW1990 was cultured in DMEM media for this study. MTT assay was used to determine the cell growth inhibitory rate in vitro. Flow cytometry and TUNEL assay were used to detect the apoptosis of human pancreatic cancer cells before and after TL treatment. RT-PCR was used to detect the expression of apoptosis-associated gene caspase-3' bcl-2 and bax.. TL inhibited the growth of human pancreatic cancer cells in a dose-and time-dependent manner. TL induced human pancreatic cancer cells to undergo apoptosis with typically apoptotic characteristics. TUNEL assay showed that after the treatment of human pancreatic cancer cells with 40 ng/mL TL for 12 h and 24 h, the apoptotic rates of human pancreatic cancer cells increased significantly. RT-PCR demonstrated that caspase-3 and bax were significantly up-regulated in SW1990 cells treated with TL while bcl-2 mRNA was not.. TL is able to induce the apoptosis in human pancreatic cancer cells. This apoptosis may be mediated by up-regulating the expression of apoptosis-associated caspase-3 and bax gene.

Topics: Adenocarcinoma; Antineoplastic Agents, Alkylating; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Cell Line, Tumor; Cell Proliferation; Diterpenes; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Epoxy Compounds; Gene Expression Regulation, Neoplastic; Humans; Pancreatic Neoplasms; Phenanthrenes; Proto-Oncogene Proteins c-bcl-2; RNA, Messenger; Time Factors; Tripterygium; Up-Regulation

The lack of effective treatment for pancreatic cancer results in a very low survival rate. This study explores the enhancement of the therapeutic effect on human pancreatic cancer via the combination of triptolide and ionizing radiation (IR).. In vitro AsPC-1 human pancreatic cancer cells were treated with triptolide alone, IR alone, or triptolide plus IR. Cell proliferation was analyzed with sulforhodamine B (SRB) method and clonogenic survival; comparison of apoptosis induced by the above treatment was analyzed by annexin V-propidium iodide (PI) staining. Furthermore, the expression of apoptotic pathway intermediates was measured by the assay of caspase activity and Western blot. Mitochondrial transmembrane potential was determined by JC-1 assay. In vivo, AsPC-1 xenografts were treated with 0.25 mg/kg triptolide, 10 Gy IR, or triptolide plus IR. The tumors were measured for volume and weight at the end of the experiment. Tumor tissues were tested for terminal nucleotidyl transferase-mediated nick end labeling (TUNEL) and immunohistochemistry.. The combination of triptolide plus IR reduced cell survival to 21% and enhanced apoptosis, compared with single treatment. In vivo, tumor growth of AsPC-1 xenografts was reduced further in the group treated with triptolide plus IR compared with single treatment. TUNEL and immunohistochemistry of caspase-3 cleavage in tumor tissues indicated that the combination of triptolide plus IR resulted in significantly enhanced apoptosis compared with single treatments.. Triptolide in combination with ionizing radiation produced synergistic antitumor effects on pancreatic cancer both in vitro and in vivo and seems promising in the combined modality therapy of pancreatic cancer.

Topics: Animals; Antineoplastic Agents, Alkylating; Apoptosis; Cell Line, Tumor; Combined Modality Therapy; Diterpenes; Epoxy Compounds; G2 Phase; Humans; Mice; Mice, Nude; Neoplasm Transplantation; Pancreatic Neoplasms; Phenanthrenes; Transplantation, Heterologous

Pancreatic cancer is highly resistant to current chemotherapy agents. We therefore examined the effects of triptolide (a diterpenoid triepoxide) on pancreatic cancer growth and local-regional tumor spread using an orthotopic model of pancreatic cancer. We have recently shown that an increased level of HSP70 in pancreatic cancer cells confers resistance to apoptosis and that inhibiting HSP70 induces apoptosis in these cells. In addition, triptolide was recently identified as part of a small molecule screen, as a regulator of the human heat shock response. Therefore, our aims were to examine the effects of triptolide on (a) pancreatic cancer cells by assessing viability and apoptosis, (b) pancreatic cancer growth and local invasion in vivo, and (c) HSP70 levels in pancreatic cancer cells. Incubation of PANC-1 and MiaPaCa-2 cells with triptolide (50-200 nmol/L) significantly reduced cell viability, but had no effect on the viability of normal pancreatic ductal cells. Triptolide induced apoptosis (assessed by Annexin V, caspase-3, and terminal nucleotidyl transferase-mediated nick end labeling) and decreased HSP70 mRNA and protein levels in both cell lines. Triptolide (0.2 mg/kg/d for 60 days) administered in vivo decreased pancreatic cancer growth and significantly decreased local-regional tumor spread. The control group of mice had extensive local invasion into adjacent organs, including the spleen, liver, kidney, and small intestine. Triptolide causes pancreatic cancer cell death in vitro and in vivo by induction of apoptosis and its mechanism of action is mediated via the inhibition of HSP70. Triptolide is a potential therapeutic agent that can be used to prevent the progression and metastases of pancreatic cancer.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; Caspase 3; Cell Growth Processes; Cell Line, Tumor; Cytochromes c; Diterpenes; Epoxy Compounds; HSP70 Heat-Shock Proteins; Humans; Mice; Mice, Nude; Pancreatic Neoplasms; Phenanthrenes; Xenograft Model Antitumor Assays

Triptolide is a compound extracted from the Chinese herb Tripterygium wilfordii Hook. f. Triptolide has potent anticancer activity. However, the mechanisms by which triptolide exerts its anticancer activities remain unclear. To explore the molecular mechanisms involved in the anticancer activity of triptolide, we have examined the effect of triptolide on the growth of pancreatic carcinoma PANC-1 and cervical adenocarcinoma HeLa cells. We found that treatment of both HeLa and PANC-1 cells with triptolide potently suppressed cell growth and induced apoptosis, indicated by nuclear fragmentation and blebbing. In both HeLa and PANC-1 cells, apoptosis induced by triptolide was associated with activation of both caspase-3 and caspase-8, and cleavage of poly(ADP-ribose) polymerase and Bid. Moreover, in HeLa cells, caspase-9 is also significantly activated in response to triptolide. Overexpression of Bcl-2 in HeLa cells substantially attenuated triptolide-induced apoptosis. Interestingly, substitution of the 14-OH of triptolide with an acetyl group abrogated both its anticancer and its antiinflammatory activities. Our studies suggest that triptolide may exert its anticancer effects by initiating apoptosis through both death-receptor- and mitochondria-mediated pathways. Our results indicate that both the apoptosis-promoting and the antiinflammatory activities of triptolide depend on the 14-OH group.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Antineoplastic Agents, Alkylating; Apoptosis; BH3 Interacting Domain Death Agonist Protein; Carcinoma; Caspases; Diterpenes; Enzyme Activation; Epoxy Compounds; HeLa Cells; Humans; Pancreatic Neoplasms; Phenanthrenes; Proto-Oncogene Proteins c-bcl-2; Structure-Activity Relationship; Tumor Cells, Cultured

A tylophorine analogue, DCB-3503, has been shown to have potent activity against tumor growth in vitro and in vivo, as well as activity in an autoimmune disease model in vivo. This study focuses on investigating the mechanisms responsible for antitumor activity of DCB-3503. The concentrations for inhibiting 50% growth/colony formation ability are 50/162 and 40/149 nmol/L for PANC-1 and HPAC cells, respectively. The growth inhibition effects are associated with DCB-3503-induced reprogramming of tumor cells. DCB-3503 could interfere with cell cycle progression. Several cell cycle regulatory proteins, including cyclin D(1), are down-regulated by DCB-3503. Using several different transcription elements coupled with a reporter gene, it was found that the nuclear factor-kappaB (NF-kappaB) signaling pathway is the most sensitive pathway mediator affected by DCB-3503. The inhibition of NF-kappaB activity is dependent on the down-regulation of nuclear phosphorylated p65, a component of the active form of the NF-kappaB complex. Such a decrease in nuclear phosphorylated p65 can be reversed by a proteosome inhibitor. Furthermore, the activity and protein expression of nuclear IkappaB kinase alpha, which is responsible for p65 phosphorylation, is suppressed and down-regulated in cells treated with DCB-3503. In summary, DCB-3503 could affect cell cycle regulatory proteins and is a potent modulator of NF-kappaB function. It is a potentially useful compound in the management of cancers in which cyclin D1 overexpression and high NF-kappaB activity play a pivotal role.

Topics: Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Down-Regulation; Humans; I-kappa B Kinase; I-kappa B Proteins; Indolizines; NF-kappa B; NF-KappaB Inhibitor alpha; Pancreatic Neoplasms; Phenanthrenes; Signal Transduction; Transcription Factor RelA; Tumor Stem Cell Assay