gdc-0449 and Pancreatic-Neoplasms

Pancreatic ductal adenocarcinoma (PDAC) is among the most devastating human malignancies, with approximately 20-30% of PDAC patients receiving the surgical resection with curative intent. Although many studies have focused on finding ideal "drug chaperones" that facilitate and/or potentiate the effects of gemcitabine (GEM) in pancreatic cancer, a significant benefit in overall survival could not be demonstrated for any of these combination therapies in PDAC. Given that pancreatic cancer is characterized by desmoplasia and the dual biological roles of stroma in pancreatic cancer, we reassess the importance of stroma in GEM-based therapeutic approaches in light of current findings. This review is focused on understanding the role of stromal components in the extrinsic resistance to GEM and whether anti-stroma therapies have a positive effect on the GEM delivery. This work contributes to the development of novel and promising combination GEM-based regimens that have achieved significant survival benefits for the patients with pancreatic cancer.

Topics: Albumins; Anilides; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Pancreatic Ductal; Deoxycytidine; Drug Resistance, Neoplasm; Drug Synergism; Gemcitabine; Gene Expression Regulation, Neoplastic; Humans; Hyaluronic Acid; Osteonectin; Paclitaxel; Pancreatectomy; Pancreatic Neoplasms; Pyridines; Stromal Cells; Survival Analysis; Treatment Outcome

Pancreatic cancer is a uniformly lethal malignancy with an abundant dense desmoplastic stroma. Because of its dense stroma, conventional drugs were considered to not penetrate this physical barrier, and this caused a systemic drug resistance. Thus, abolishing this barrier with targeted agents is considered to improve the efficiency of chemotherapeutic treatment. The Hedgehog (Hh) signaling pathway is a critical regulator of pancreas development and plays diversified roles in pancreatic cancer stroma and neoplastic cells. Increasing Hh expression in neoplastic cells added desmoplastic stroma accumulation in orthotopic tumors, and Hh inhibitors that target the stroma have an ability to prolong the overall survival of Pdx-1-Cre/KrasG12D/p53R172H mice models via deleting the stromal components and increasing vascularity in pancreatic tumor. However, the failure of translation from bench to bedside indicate the complexity of the relationship between Hh signaling and desmoplastic stroma, and more insights into the complex relationships between Hh signaling pathway and stroma, even tumor cells, might help redesign Hh-targeted therapy. In this review, we discuss the possible mechanism of translation of Hh inhibitor in the clinic from pathology to molecular mechanism.

Topics: Anilides; Animals; Disease Models, Animal; Gene Expression Regulation, Neoplastic; Hedgehog Proteins; Humans; Mice; Pancreatic Neoplasms; Pyridines; Signal Transduction; Stromal Cells

To conduct a systematic review of the role that the hedgehog signaling pathway has in pancreatic cancer tumorigenesis.. PubMed search (2000-2010) and literature based references.. Firstly, in 2009 a genetic analysis of pancreatic cancers found that a core set of 12 cellular signaling pathways including hedgehog were genetically altered in 67-100% of cases. Secondly, in vitro and in vivo studies of treatment with cyclopamine (a naturally occurring antagonist of the hedgehog signaling pathway component; Smoothened) has shown that inhibition of hedgehog can abrogate pancreatic cancer metastasis. Thirdly, experimental evidence has demonstrated that sonic hedgehog (Shh) is correlated with desmoplasia in pancreatic cancer. This is important because targeting the Shh pathway potentially may facilitate chemotherapeutic drug delivery as pancreatic cancers tend to have a dense fibrotic stroma that extrinsically compresses the tumor vasculature leading to a hypoperfusing intratumoral circulation. It is probable that patients with locally advanced pancreatic cancer will derive the greatest benefit from treatment with Smoothened antagonists. Fourthly, it has been found that ligand dependent activation by hedgehog occurs in the tumor stromal microenvironment in pancreatic cancer, a paracrine effect on tumorigenesis. Finally, in pancreatic cancer, cells with the CD44+CD24+ESA+ immunophenotype select a population enriched for cancer initiating stem cells. Shh is increased 46-fold in CD44+CD24+ESA+ cells compared with normal pancreatic epithelial cells. Medications that destruct pancreatic cancer initiating stem cells are a potentially novel strategy in cancer treatment.. Aberrant hedgehog signaling occurs in pancreatic cancer tumorigenesis and therapeutics that target the transmembrane receptor Smoothened abrogate hedgehog signaling and may improve the outcomes of patients with pancreatic cancer.

Topics: Adenocarcinoma; Anilides; Animals; Clinical Trials as Topic; Hedgehog Proteins; Humans; Neoplastic Stem Cells; Pancreatic Neoplasms; Pyridines; Signal Transduction

It has long been known that the hedgehog signaling pathway is crucial for embryonic development, in both Drosophila and vertebrate systems. During the past few years its implication in carcinogenesis has become clear and today it is acknowledged that this pathway plays a role in the malignant transformation of multiple cell types, either owing to the mutation of some of its components or to its erratic activation. New molecular targeted therapies that inhibit the pathway have shown their unquestionable efficiency in several tumours -among which basal cell carcinoma, medulloblastoma, or pancreatic adenocarcinoma. The assessment of these inhibitors in other types of tumours is currently underway with promising results, suggesting that the Sonic hedgehog signalling pathway may become one of the therapeutic targets of the future.

Topics: Anilides; Animals; Carcinoma, Basal Cell; Cerebellar Neoplasms; Embryonic Development; Embryonic Induction; Hedgehog Proteins; Humans; Lung Neoplasms; Medulloblastoma; Molecular Targeted Therapy; Mutation; Neoplasms; Neoplastic Stem Cells; Pancreatic Neoplasms; Patched Receptors; Patient Selection; Pyridines; Receptors, Cell Surface; Signal Transduction; Skin Neoplasms; Small Cell Lung Carcinoma

Interplay between the Hedgehog (HH) and epidermal growth factor receptor (EGFR) pathways modulating the outcome of their signaling activity have been reported in various cancers including pancreatic ductal adenocarcinoma (PDAC). Therefore, simultaneous targeting of these pathways may be clinically beneficial. This Phase I study combined HH and EGFR inhibition in metastatic PDAC patients.. Combined effects of HH and EGFR inhibition using Vismodegib and Erlotinib with or without gemcitabine in metastatic solid tumors were assessed by CT. Another cohort of patients with metastatic PDAC was evaluated by FDG-PET and tumor biopsies-derived biomarkers.. Treatment was well tolerated with the maximum tolerated dose cohort experiencing no grade 4 toxicities though 25% experienced grade 3 adverse effects. Recommended phase II dose of Vismodegib and Erlotinib were each 150 mg daily. No tumor responses were observed although 16 patients achieved stable disease for 2-7 cycles. Paired biopsy analysis before and after first cycle of therapy in PDAC patients showed reduced GLI1 mRNA, phospho-GLI1 and associated HH target genes in all cases. However, only half of the cases showed reduced levels of desmoplasia or changes in fibroblast markers. Most patients had decreased phospho-EGFR levels.. Vismodegib and Erlotinib combination was well-tolerated although overall outcome in patients with metastatic PDAC was not significantly impacted by combination treatment. Biomarker analysis suggests direct targets inhibition without significantly affecting the stromal compartment. These findings conflict with pre-clinical mouse models, and thus warrant further investigation into how upstream inhibition of these pathways is circumvented in PDAC.

Topics: Adult; Aged; Aged, 80 and over; Anilides; Antineoplastic Agents; Biomarkers; Erlotinib Hydrochloride; Female; Humans; Male; Middle Aged; Pancreatic Neoplasms; Pyridines

The Hedgehog (Hh) signalling pathway is overexpressed in pancreatic ductal adenocarcinoma (PDA). Preclinical studies have shown that Hh inhibitors reduce pancreatic cancer stem cells (pCSC), stroma and Hh signalling.. Patients with previously untreated metastatic PDA were treated with gemcitabine and nab-paclitaxel. Vismodegib was added starting on the second cycle. The primary endpoint was progression-free survival (PFS) as compared with historical controls. Tumour biopsies to assess pCSC, stroma and Hh signalling were obtained before treatment and after cycle 1 (gemcitabine and nab-paclitaxel) or after cycle 2 (gemcitabine and nab-paclitaxel plus vismodegib).. Seventy-one patients were enrolled. Median PFS and overall survival (OS) were 5.42 months (95% confidence interval [CI]: 4.37-6.97) and 9.79 months (95% CI: 7.85-10.97), respectively. Of the 67 patients evaluable for response, 27 (40%) had a response: 26 (38.8%) partial responses and 1 complete response. In the tumour samples, there were no significant changes in ALDH + pCSC following treatment.. Adding vismodegib to chemotherapy did not improve efficacy as compared with historical rates observed with chemotherapy alone in patients with newly diagnosed metastatic pancreatic cancer. This study does not support the further evaluation of Hh inhibitors in this patient population.. ClinicalTrials.gov Identifier: NCT01088815.

Topics: Aged; Albumins; Anilides; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Pancreatic Ductal; Deoxycytidine; Female; Gemcitabine; Humans; Male; Middle Aged; Paclitaxel; Pancreatic Neoplasms; Progression-Free Survival; Pyridines; Treatment Outcome

Sonic hedgehog (SHH), an activating ligand of smoothened (SMO), is overexpressed in > 70% of pancreatic cancers (PCs). We investigated the impact of vismodegib, an SHH antagonist, plus gemcitabine (GV) or gemcitabine plus placebo (GP) in a multicenter phase Ib/randomized phase II trial and preclinical PC models.. Patients with PC not amenable to curative therapy who had received no prior therapy for metastatic disease and had Karnofsky performance score ≥ 80 were enrolled. Patients were randomly assigned in a one-to-one ratio to GV or GP. The primary end point was progression-free-survival (PFS). Exploratory correlative studies included serial SHH serum levels and contrast perfusion computed tomography imaging. To further investigate putative biologic mechanisms of SMO inhibition, two autochthonous pancreatic cancer models (Kras(G12D); p16/p19(fl/fl); Pdx1-Cre and Kras(G12D); p53(R270H/wt); Pdx1-Cre) were studied.. No safety issues were identified in the phase Ib portion (n = 7), and the phase II study enrolled 106 evaluable patients (n = 53 in each arm). Median PFS was 4.0 and 2.5 months for GV and GP arms, respectively (95% CI, 2.5 to 5.3 and 1.9 to 3.8, respectively; adjusted hazard ratio, 0.81; 95% CI, 0.54 to 1.21; P = .30). Median overall survival (OS) was 6.9 and 6.1 months for GV and GP arms, respectively (95% CI, 5.8 to 8.0 and 5.0 to 8.0, respectively; adjusted hazard ratio, 1.04; 95% CI, 0.69 to 1.58; P = .84). Response rates were not significantly different. There were no significant associations between correlative markers and overall response rate, PFS, or OS. Preclinical trials revealed no significant differences with vismodegib in drug delivery, tumor growth rate, or OS in either model.. The addition of vismodegib to gemcitabine in an unselected cohort did not improve overall response rate, PFS, or OS in patients with metastatic PC. Our preclinical and clinical results revealed no statistically significant differences with respect to drug delivery or treatment efficacy using vismodegib.

Topics: Adult; Aged; Anilides; Animals; Antineoplastic Combined Chemotherapy Protocols; Deoxycytidine; Disease-Free Survival; Female; Gemcitabine; Hedgehog Proteins; Humans; Kaplan-Meier Estimate; Karnofsky Performance Status; Male; Mice; Middle Aged; Neoplasm Staging; Odds Ratio; Pancreatic Neoplasms; Pyridines; Signal Transduction; Treatment Outcome

The hedgehog (HH) signaling pathway is a key regulator in tumorigenesis of pancreatic adenocarcinoma and is upregulated in pancreatic adenocarcinoma cancer stem cells (CSCs). GDC-0449 is an oral small-molecule inhibitor of the HH pathway. This study assessed the effect of GDC-0449-mediated HH inhibition in paired biopsies, followed by combined treatment with gemcitabine, in patients with metastatic pancreatic adenocarcinoma.. Twenty-five patients were enrolled of which 23 underwent core biopsies at baseline and following 3 weeks of GDC-0449. On day 29, 23 patients started weekly gemcitabine while continuing GDC-0449. We evaluated GLI1 and PTCH1 inhibition, change in CSCs, Ki-67, fibrosis, and assessed tumor response, survival and toxicity.. On pretreatment biopsy, 75% of patients had elevated sonic hedgehog (SHH) expression. On posttreatment biopsy, GLI1 and PTCH1 decreased in 95.6% and 82.6% of 23 patients, fibrosis decreased in 45.4% of 22, and Ki-67 in 52.9% of 17 evaluable patients. No significant changes were detected in CSCs pre- and postbiopsy. The median progression-free and overall survival for all treated patients were 2.8 and 5.3 months. The response and disease control rate was 21.7% and 65.2%. No significant correlation was noted between CSCs, fibrosis, SHH, Ki-67, GLI1, PTCH1 (baseline values or relative change on posttreatment biopsy), and survival. Grade ≥ 3 adverse events were noted in 56% of patients.. We show that GDC-0449 for 3 weeks leads to downmodulation of GLI1 and PTCH1, without significant changes in CSCs compared with baseline. GDC-0449 and gemcitabine were not superior to gemcitabine alone in the treatment of metastatic pancreatic cancer.

Topics: Adenocarcinoma; Aged; Aged, 80 and over; Anilides; Antineoplastic Combined Chemotherapy Protocols; Biomarkers; Biopsy; Deoxycytidine; Female; Gemcitabine; Hedgehog Proteins; Humans; Male; Middle Aged; Neoplasm Metastasis; Neoplastic Stem Cells; Pancreatic Neoplasms; Pyridines; Signal Transduction; Treatment Outcome

Effective treatments for pancreatic ductal adenocarcinoma (PDAC) are lacking, and targeted agents have demonstrated limited efficacy. It has been speculated that a rare population of cancer stem cells (CSCs) drives growth, therapy resistance, and rapid metastatic progression in PDAC. These CSCs demonstrate high clonogenicity in vitro and tumorigenic potential in vivo. However, their relevance in established PDAC tissue has not been determined. Here, we use marker-independent stochastic clonal labeling, combined with quantitative modeling of tumor expansion, to uncover PDAC tissue growth dynamics. We find that in contrast to the CSC model, all PDAC cells display clonogenic potential in situ. Furthermore, the proximity to activated cancer-associated fibroblasts determines tumor cell clonogenicity. This means that the microenvironment is dominant in defining the clonogenic activity of PDAC cells. Indeed, manipulating the stroma by Hedgehog pathway inhibition alters the tumor growth mode, revealing that tumor-stroma crosstalk shapes tumor growth dynamics and clonal architecture.

Topics: Anilides; Animals; Antineoplastic Agents; Cancer-Associated Fibroblasts; Carcinoma, Pancreatic Ductal; Cell Communication; Cell Line, Tumor; Cell Lineage; Cell Proliferation; Female; Hedgehog Proteins; Humans; Male; Mice, Inbred NOD; Mice, Nude; Mice, SCID; Neoplastic Stem Cells; Pancreatic Neoplasms; Pyridines; Signal Transduction; Stromal Cells; Time Factors; Tumor Burden; Tumor Microenvironment; Xenograft Model Antitumor Assays

Pancreatic cancer (PC) remains a therapeutic challenge because of its intrinsic and extrinsic chemoresistance mechanisms. Here, we report that C-

Topics: Anilides; Animals; Antimetabolites, Antineoplastic; Benzylamines; Cell Communication; Cell Survival; Coculture Techniques; Cyclams; Deoxycytidine; Drug Resistance, Neoplasm; Gemcitabine; Hedgehog Proteins; Heterocyclic Compounds; Humans; Mice; Mice, Nude; Pancreatic Neoplasms; Pancreatic Stellate Cells; Pyridines; Reactive Oxygen Species; Receptors, CXCR4; RNA Interference; RNA, Small Interfering; Signal Transduction

Preclinical data indicated a functional and molecular interaction between Hedgehog (HH)/GLI and PI3K-AKT-mTOR pathways promoting pancreatic ductal adenocarcinoma (PDAC). A phase I study was conducted of Vismodegib and Sirolimus combination to evaluate maximum tolerated dose (MTD) and preliminary anti-tumor efficacy.. Cohort I included advanced solid tumors patients following a traditional 3 + 3 design. Vismodegib was orally administered at 150 mg daily with Sirolimus starting at 3 mg daily, increasing to 6 mg daily at dose level 2. Cohort II included only metastatic PDAC patients. Anti-tumor efficacy was evaluated every two cycles and target assessment at pre-treatment and after a single cycle.. Nine patient were enrolled in cohort I and 22 patients in cohort II. Twenty-eight patients were evaluated for dose-limiting toxicities (DLTs). One DLT was observed in each cohort, consisting of grade 2 mucositis and grade 3 thrombocytopenia. The MTD for Vismodegib and Sirolimus were 150 mg daily and 6 mg daily, respectively. The most common grade 3-4 toxicities were fatigue, thrombocytopenia, dehydration, and infections. A total of 6 patients had stable disease. No partial or complete responses were observed. Paired biopsy analysis before and after the first cycle in cohort II consistently demonstrated reduced GLI1 expression. Conversely, GLI and mTOR downstream targets were not significantly affected.. The combination of Vismodegib and Sirolimus was well tolerated. Clinical benefit was limited to stable disease in a subgroup of patients. Targeting efficacy demonstrated consistent partial decreases in HH/GLI signaling with limited impact on mTOR signaling. These findings conflict with pre-clinical models and warrant further investigations.

Topics: Adult; Aged; Anilides; Antineoplastic Combined Chemotherapy Protocols; Biopsy; Carcinoma, Pancreatic Ductal; Drug Therapy, Combination; Female; Hedgehog Proteins; Humans; Immunosuppressive Agents; Male; Maximum Tolerated Dose; Middle Aged; Negative Results; Neoplasm Metastasis; Pancreatic Neoplasms; Pyridines; RNA, Neoplasm; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Treatment Outcome

A pH-responsive nanoparticle platform, based on PEG-b-poly (carbonate) block copolymers have been proposed that can respond to low pH as found in many cancer micro- and intracellular environment, including that in pancreatic cancer. The hydrophobic domain, i.e., the poly (carbonate) segment has been substituted with tertiary amine side chains, such as N, N'-dibutylethylenediamine (pK

Topics: Anilides; Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Proliferation; Deoxycytidine; Drug Carriers; Drug Delivery Systems; Gemcitabine; Humans; Hydrogen-Ion Concentration; Mice; Mice, Nude; Micelles; Nanoparticles; Pancreatic Neoplasms; Polycarboxylate Cement; Polyethylene Glycols; Polymers; Pyridines; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Aberrant activation of Hedgehog (Hh) signaling is associated with the development of numerous human cancers. Vismodegib is the first Hh inhibitor approved for anti-cancer therapy by targeting Smoothened (SMO), a critical regulator of the Hh pathway. However, acquisition of drug resistance to vismodegib occurs overtime. Apoptosis is a prevalent form of programmed cell death that is executed by caspases. Induction of tumor cell apoptosis represents an attractive therapeutic strategy to eliminate tumor cells. To explore new Hh antagonists with apoptosis-inducing activity, we screened a set of ∼300 potential SMO antagonists with novel scaffold structures. Hh003 was found to induce caspase-dependent apoptosis while vismodegib did not activate apoptotic response in human colon and pancreatic cancer cells. Compared to vismodegib, Hh003 exerted similar inhibitory effects on the Hh pathway. Hh003 could induce caspase8 activation and the silence of caspase8 significantly inhibited Hh003-induced apoptosis. Remarkably, Hh003 showed stronger inhibitory effects on the formation of tumor colonies in vitro and colorectal tumor growth in vivo than vismodegib. These findings suggest that Hh003 exerts enhanced anti-tumor effects by activating caspase8-dependent apoptosis compared to vismodegib. The combined property of Hh inhibition and apoptosis induction of Hh003 presents great potential for the development of novel anti-cancer therapy.

Topics: Anilides; Antineoplastic Agents; Apoptosis; Caspase 8; Colonic Neoplasms; Drug Discovery; Drug Screening Assays, Antitumor; HCT116 Cells; Hedgehog Proteins; Humans; Molecular Targeted Therapy; Pancreatic Neoplasms; Pyridines; Signal Transduction

Topics: Anilides; Animals; Antineoplastic Agents; Apoptosis; Biomarkers, Tumor; Carcinogenesis; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Movement; Drug Design; Drug Evaluation, Preclinical; Hedgehog Proteins; Humans; Inhibitory Concentration 50; Male; Mice; Molecular Docking Simulation; Nanoparticles; Neoplastic Stem Cells; Organ Specificity; Pancreatic Neoplasms; Pyridines; Smoothened Receptor; Spheroids, Cellular; Structure-Activity Relationship

Targeting the rich extracellular matrix of desmoplastic tumors has been successfully shown to normalize collagen and hyaluronan levels and re-engineer intratumoral mechanical forces, improving tumor perfusion and chemotherapy. As far as targeting the abundant cancer-associated fibroblasts (CAFs) in desmoplastic tumors is concerned, while both pharmacologic inhibition of the sonic-hedgehog pathway and genetic depletion of fibroblasts have been employed in pancreatic cancers, the results between the two methods have been contradictory. In this study, we employed vismodegib to inhibit the sonic-hedgehog pathway with the aim to i) elucidate the mechanism of how CAFs depletion improves drug delivery, ii) extent and evaluate the potential use of sonic-hedgehog inhibitors to breast cancers, and iii) investigate whether sonic-hedgehog inhibition improves not only chemotherapy, but also the efficacy of the most commonly used breast cancer nanomedicines, namely Abraxane® and Doxil®. We found that treatment with vismodegib normalizes the tumor microenvironment by reducing the proliferative CAFs and in cases the levels of collagen and hyaluronan. These modulations re-engineered the solid and fluid stresses in the tumors, improving blood vessel functionality. As a result, the delivery and efficacy of chemotherapy was improved in two models of pancreatic cancer. Additionally, vismodegib treatment significantly improved the efficacy of both Abraxane and Doxil in xenograft breast tumors. Our results suggest the use of vismodegib, and sonic hedgehog inhibitors in general, to enhance cancer chemo- and nanotherapy.

Topics: Albumin-Bound Paclitaxel; Anilides; Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cell Line, Tumor; Doxorubicin; Drug Delivery Systems; Extracellular Matrix; Female; Fibroblasts; Hedgehog Proteins; Humans; Male; Mice; Mice, Inbred NOD; Mice, SCID; Nanoparticles; Pancreatic Neoplasms; Polyethylene Glycols; Pyridines; Tumor Microenvironment; Xenograft Model Antitumor Assays

Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer with a dismal overall prognosis mainly unchanged over the past decades. PDAC is generally refractory to conventional treatments, and thus novel therapies are urgently needed. Recently, accumulating evidence has indicated that human pancreatic stellate cells (PSCs) facilitate PDAC development and drug resistance through paracrine activation of hedgehog pathway. Here, we report that smart SN38 (active metabolite of irinotecan) polymeric prodrug-based nanoparticles effectively encapsulate the commercial hedgehog pathway inhibitor GDC-0449 for co-delivery. More intriguingly, we obtained size-tunable nanoparticles with increased GDC-0449 loading efficiency by simply extending the chain length of the hydrophobic SN38 block. To better evaluate the efficacy and investigate the synergistic mechanisms, we immortalized human PSCs and established fibroblast-containing models in vitro and in vivo. In PSCs, BxPC-3 cells and MIA PaCa-2 cells, GDC-0449 suppressed the co-culture induced up-regulations of the two drug resistance contributors: sonic hedgehog transcription factor glioma-associated protein1 (GLI-1) and UGT1A glucuronosyltransferase. Importantly, the nanoparticle-mediated co-delivery system exhibited potent antitumor efficacy with enhanced apoptosis and reduced collagen, α-SMA and GLI-1 expression in tumor tissues. These findings reveal a potential strategy to utilize nanoparticle-mediated drug co-delivery platform as an effective combination therapy for fibroblast-enriched PDAC.

Topics: Anilides; Animals; Antineoplastic Agents; Camptothecin; Coculture Techniques; Drug Resistance, Neoplasm; Drug Synergism; Female; Fibroblasts; Hedgehog Proteins; Humans; Irinotecan; Mice, Inbred BALB C; Mice, Inbred ICR; Mice, Nude; Nanoparticles; Pancreatic Neoplasms; Prodrugs; Pyridines; Rats, Sprague-Dawley; Signal Transduction

Pancreatic cancer is one of the most lethal human cancers that currently does not have effective therapies. Novel treatments including nanomedicines and combination therapies are thus urgently needed for these types of deadly diseases. A key feature of pancreatic cancer is its tumor protective dense stroma, which is generated by cancer-associated fibroblasts (CAFs). The interaction between CAFs and pancreatic cancer cells abnormally activates sonic hedgehog (SHH) signaling and facilitates tumor growth, metastasis, and drug resistance. Here, we report that the commercial SHH inhibitor GDC-0449 reverses fibroblast-induced resistance to doxorubicin in Smoothened (SMO)-positive pancreatic cancer cells by downregulating SHH signaling proteins. Importantly, the synergistic combination of GDC-0449 with PEG-PCL-Dox exhibited potent antitumor efficacy in a BxPC-3 tumor xenograft model, whereas single treatments did not significantly inhibit tumor growth. Our findings reveal a potential treatment strategy for fibroblast-enriched pancreatic cancer.

Topics: Anilides; Animals; Apoptosis; Cancer-Associated Fibroblasts; Cell Line, Tumor; Disease Models, Animal; Doxorubicin; Drug Synergism; Female; Hedgehog Proteins; Humans; Mice; Pancreatic Neoplasms; Pyridines; Signal Transduction; Smoothened Receptor; Tumor Microenvironment; Xenograft Model Antitumor Assays

Hedgehog (Hh) signaling plays an important role in the development and metastasis of pancreatic ductal adenocarcinoma (PDAC). Although gemcitabine (GEM) has been used as a first-line therapy for PDAC, its rapid metabolism and short plasma half-life restrict its use as a single chemotherapy. Combination therapy with more than one drug is a promising approach for treating cancer. Herein, we report the use of methoxy poly(ethylene glycol)-block-poly(2-methyl-2-carboxyl-propylene carbonate)-graft-dodecanol (mPEG-b-PCC-g-DC) copolymer for conjugating GEM and encapsulating a Hh inhibitor, vismodegib (GDC-0449), into its hydrophobic core for treating PDAC. Our objective was to determine whether the micelle mixtures of these two drugs could show better response in inhibiting Hh signaling pathway and restraining the proliferation and metastasis of pancreatic cancer. The in vivo stability of GEM significantly increased after conjugation, which resulted in its increased antitumor efficacy. Almost 80% of encapsulated GDC-0449 and 19% conjugated GEM were released in vitro at pH 5.5 in 48 h in a sustained manner. The invasion, migration, and colony forming features of MIA PaCa-2 cells were significantly inhibited by micelle mixture carrying GEM and GDC-0449. Remarkable increase in PARP cleavage and Bax proved increased apoptosis by this combination formulation compared to individual micelles. This combination therapy efficiently inhibited tumor growth, increased apoptosis, reduced Hh ligands PTCH-1 and Gli-1, and lowered EMT-activator ZEB-1 when injected to athymic nude mice bearing subcutaneous tumor generated using MIA PaCa-2 cells compared to monotherapy as observed from immunohistochemical analysis. In conclusion, micelle mixtures carrying GEM and GDC-0449 have the potential to treat pancreatic cancer.

Topics: Adenocarcinoma; Anilides; Animals; Antimetabolites, Antineoplastic; Apoptosis; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cell Movement; Cell Proliferation; Deoxycytidine; Dodecanol; Gemcitabine; Humans; Male; Mice; Mice, Nude; Micelles; Pancreatic Neoplasms; Polyethylene Glycols; Polymers; Propane; Pyridines; Signal Transduction

Successful treatment of pancreatic ductal adenocarcinoma (PDAC) remains a challenge due to the desmoplastic microenvironment that promotes both tumor growth and metastasis and forms a barrier to chemotherapy. Hedgehog (Hh) signaling is implicated in initiation and progression of PDAC and also contributes to desmoplasia. While Hh levels are increased in pancreatic cancer cells, levels of tumor suppressor miR-let7b, which targets several genes involved in PDAC pathogenesis, is downregulated. Therefore, our overall objective was to inhibit Hh pathway and restore miR-let7b simultaneously for synergistically treating PDAC. miR-let7b and Hh inhibitor GDC-0449 could inhibit the proliferation of human pancreatic cancer cells (Capan-1, HPAF-II, T3M4, and MIA PaCa-2), and there was synergistic effect when miR-let7b and GDC-0449 were coformulated into micelles using methoxy poly(ethylene glycol)-block-poly(2-methyl- 2-carboxyl-propylenecarbonate-graft-dodecanol-graft-tetraethylene-pentamine) (mPEG-b-PCC-g-DC-g-TEPA). This copolymer self-assembled into micelles of <100 nm and encapsulated hydrophobic GDC-0449 into its core with 5% w/w drug loading and allowed complex formation between miR-let7b and its cationic pendant chains. Complete polyplex formation with miRNA was observed at the N/P ratio of 16/1. Almost 80% of GDC-0449 was released from the polyplex in a sustained manner in 2 days. miRNA in the micelle formulation was stable for up to 24 h in the presence of serum and high uptake efficiency was achieved with low cytotoxicity. This combination therapy effectively inhibited tumor growth when injected to athymic nude mice bearing ectopic tumor generated using MIA PaCa-2 cells compared to micelles carrying GDC-0449 or miR-let7b alone. Immunohistochemical analysis revealed decreased tumor cell proliferation with increased apoptosis in the animals treated with miR-let7b and GDC-0449 combination.

Topics: Adenocarcinoma; Alkenes; Anilides; Animals; Carbonates; Cations; Cell Line, Tumor; Cell Survival; Disease Progression; Dodecanol; Drug Carriers; Drug Delivery Systems; Endosomes; Ethylenediamines; Hedgehog Proteins; Humans; Immunohistochemistry; In Situ Nick-End Labeling; Male; Mice; Mice, Nude; Micelles; MicroRNAs; Neoplasm Transplantation; Pancreatic Neoplasms; Polyethylene Glycols; Polymers; Pyridines; Signal Transduction

Pancreatic adenocarcinoma is one of the most aggressive malignancies and the fourth leading cause of cancer-related mortality in the United States. The majority of patients are diagnosed at advanced stage with inoperable locally advanced tumors or metastatic disease, and palliative chemotherapy remains the best therapeutic option for these patients. Despite intensive clinical and pre-clinical research over the last few years, the combination of the anti-metabolite drug gemcitabine with the targeted agent erlotinib, is considered standard of care in the treatment of these patients, with only minimal or modest efficacy. Therefore, novel therapeutic approaches are currently under clinical investigation in an attempt to produce more definite results for this fatal disease. In this paper we summarize five most interesting research abstracts as presented at the 2013 American Society of Clinical Oncology (ASCO) Annual Meeting. In two studies, nimotuzumab, a monoclonal antibody against epidermal growth factor receptor (EGFR) (Abstract #4009) and bavituximab, a monoclonal antibody against phosphatidylserine (Abstract #4054) are tested in combination with gemcitabine in patients with advanced pancreatic cancer. Abstract #4012 is a study of gemcitabine with vismodegib, a novel hedgehog pathway inhibitor, whereas in Abstract #4035, toxicity and efficacy results of sunitinib in combination with gemcitabine in patients with pancreatic adenocarcinoma are presented. Lastly, safety results of pimasertib, a novel mitogen-activated protein kinase kinase (MEK) inhibitor, combined with the standard gemcitabine are presented in Abstract #4041.

Topics: Adenocarcinoma; Anilides; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Deoxycytidine; Gemcitabine; Humans; Indoles; Niacinamide; Pancreatic Neoplasms; Protein Kinase Inhibitors; Pyridines; Pyrroles; Sunitinib; Treatment Outcome

Topics: Albumin-Bound Paclitaxel; Albumins; Anilides; Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Autophagy; Chloroquine; Clinical Trials as Topic; Delayed Diagnosis; Deoxycytidine; Disease Progression; Gemcitabine; Genes, ras; Humans; Mice; Molecular Targeted Therapy; Mutation; Off-Label Use; Paclitaxel; Pancreatic Neoplasms; Pyridines; Signal Transduction; Transcription Factors; United States

Recent evidence from in vitro and in vivo studies has demonstrated that aberrant reactivation of the Sonic Hedgehog (SHH) signaling pathway regulates genes that promote cellular proliferation in various human cancer stem cells (CSCs). Therefore, the chemotherapeutic agents that inhibit activation of Gli transcription factors have emerged as promising novel therapeutic drugs for pancreatic cancer. GDC-0449 (Vismodegib), orally administrable molecule belonging to the 2-arylpyridine class, inhibits SHH signaling pathway by blocking the activities of Smoothened. The objectives of this study were to examine the molecular mechanisms by which GDC-0449 regulates human pancreatic CSC characteristics in vitro.. GDC-0499 inhibited cell viability and induced apoptosis in three pancreatic cancer cell lines and pancreatic CSCs. This inhibitor also suppressed cell viability, Gli-DNA binding and transcriptional activities, and induced apoptosis through caspase-3 activation and PARP cleavage in pancreatic CSCs. GDC-0449-induced apoptosis in CSCs showed increased Fas expression and decreased expression of PDGFRα. Furthermore, Bcl-2 was down-regulated whereas TRAIL-R1/DR4 and TRAIL-R2/DR5 expression was increased following the treatment of CSCs with GDC-0449. Suppression of both Gli1 plus Gli2 by shRNA mimicked the changes in cell viability, spheroid formation, apoptosis and gene expression observed in GDC-0449-treated pancreatic CSCs. Thus, activated Gli genes repress DRs and Fas expressions, up-regulate the expressions of Bcl-2 and PDGFRα and facilitate cell survival.. These data suggest that GDC-0499 can be used for the management of pancreatic cancer by targeting pancreatic CSCs.

Topics: Anilides; Apoptosis; Cell Line, Tumor; Cell Survival; Hedgehog Proteins; Humans; Neoplastic Stem Cells; Pancreatic Neoplasms; Pyridines; Receptors, G-Protein-Coupled; Signal Transduction; Smoothened Receptor; Transcription Factors