14-o-phosphonooxymethyltriptolide and Pancreatic-Neoplasms

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

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

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

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

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

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 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

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

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