Combined EGFR targeted therapy in a novel in vivo pancreas cancer model

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 14063-14063
Author(s):  
A. Jimeno ◽  
A. Chan ◽  
B. Rubio-Viqueira ◽  
X. Zhang ◽  
G. Cusatis ◽  
...  
Keyword(s):  
Drug Evaluation ◽  
Single Agent ◽  
Xenograft Model ◽  
Egfr Inhibitors ◽  
Egfr Mutations ◽  
Proliferation Index ◽  
Pathway Activation ◽  
Molecule Inhibitor ◽  
Genomic Markers

14063 Background: EGFR inhibitors have a definite but limited activity in pancreatic cancer (PaCa). We have reported enhanced activity of dual EGFR therapy with a small molecule inhibitor (erlotinib) plus a monoclonal antibody (cetuximab) in head and neck cancer models. Human xenografted tumors recapitulate better the pathobiology of cancer than existing cell lines. Here we explored a dual EGFR targeting approach using a direct PaCa xenograft model, and sought after markers predicting efficacy. Methods: PaCa specimens obtained at the time surgery were implanted in nude mice and expanded to develop cohorts of tumor bearing mice suitable for drug evaluation. Ten cases were expanded, and within each case 4 groups of 6–8 mice each were treated with vehicle, erlotinib, cetuximab, and the combination of both for 28 days. Gene mutation analysis, gene amplification by fluorescence-in-situ hybridization, and immunohistochemistry (IHC) were done with untreated samples. Results: Two cases were sensitive to both single agents, but the combination did not induce higher efficacy in those. Two additional cases that were resistant to both single agents became sensitive with the combination. No egfr mutations were detected. Three and four cases carried low and high egfr polysomy (defined as [[Unsupported Character - ]] 4 copies in 10–40% and [[Unsupported Character - ]] 40% of the cells, respectively). No correlation was found between egfr copy number and efficacy. By IHC sensitive cases had a lower Ki67 proliferation index, and higher EGFR and nuclear pMAPK staining than resistant cases. The degree of Ki67 decrease after therapy correlated with efficacy. In cases resistant to the single agents but sensitive to the combination nuclear pMAPK only decreased with the dual targeting. Cases with high egfr polysomy were more labile to pharmacodynamic effects after treatment (such as EGFR or pMAPK decreases). Conclusions: EGFR inhibitors showed modest single agent antitumor effect that was enhanced with dual EGFR therapy in PaCa. No genomic markers predicted efficacy, although high egfr polysomy was associated with deeper pharmacodynamic inhibition, conceivably suggesting a phenomenon of pathway addiction. Higher pathway activation by IHC was linked with higher activity. No significant financial relationships to disclose.

Azacitidine/Decitabine Synergism with the NEDD8-Activating Enzyme Inhibitor MLN4924 in Pre-Clinical AML Models

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 578-578 ◽  
Author(s):  
Peter G Smith ◽  
Tary Traore ◽  
Steve Grossman ◽  
Usha Narayanan ◽  
Jennifer S Carew ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Death ◽  
Synthetic Lethality ◽  
Single Agent ◽  
Xenograft Model ◽  
S Phase ◽  
Myelogenous Leukemia ◽  
Phase Accumulation

Abstract Abstract 578 MLN4924 is an investigational small molecule inhibitor of NEDD8-activating enzyme that has shown clinical activity in a Phase I clinical trial in Acute Myelogenous Leukemia (AML). To identify potential combination partners of MLN4924 we performed a high-throughput viability screen in AML cells with 40 approved and investigational agents. In vitro characterization of AML cell lines revealed two distinct cell cycle phenotypes suggesting alternate mechanism of action following MLN4924 inhibition of NAE. One group demonstrated moderate S-phase accumulation with greater than 4N DNA content consistent with DNA-rereplication as a result of CDT1 dysregulation. The second group demonstrated distinct and rapid accumulation of subG1 cells without S-phase accumulation or DNA re-replication suggesting induction of apoptosis and cell death. These observations led us to choose two cells lines representative of each mechanism to understand potential for synergy in AML cells. Two hypomethylating agents were included in the screen (decitabine and azacitidine) and were found to be synergistic with MLN4924 by Combination Index and Blending Synergy Analysis. These data were confirmed with a second NAE inhibitor that is structurally dissimilar to MLN4924. The combination of azacitidine and MLN4924 were shown to result in significantly increased DNA-damage and cell death compared to single agent alone as measured by Western Blotting and FACS analysis of cell cycle distributions. In vivo studies were performed in HL-60 and THP-1 xenografts using MLN4924 on a clinically relevant dosing schedule twice weekly. Single agent azacitidine at its Maximum Tolerated Dose (MTD) had minimal activity in the HL-60 model and was combined with a sub-optimal dose of MLN4924 that when combined induced complete and sustained tumor regressions. The mechanism for the apparent synthetic lethality in this in vivo model is currently under evaluation; however it is supported by a dramatic elevation in DNA damage and cleaved caspase-3 in vivo in the combination arm. A second xenograft model (THP-1) that was also insensitive to single agent azacitidine treatment underwent complete and sustained tumor regressions when combined with MLN4924. Thus MLN4924 and azacitidine can combine to produce synergistic antitumor activity in pre-clinical models of AML. Coupled with their non-overlapping clinical toxicities these data suggest the potential for future combination studies in clinical trials. Disclosures: Smith: Millennium Pharmaceuticals: Employment. Traore:Millennium Pharmaceuticals: Employment. Grossman:Millennium Pharmaceuticals: Employment. Narayanan:Millennium Pharmaceuticals: Employment. Carew:Millennium Pharmaceuticals: Research Funding. Lublinksky:Millennium Pharmaceuticals: Employment. Kuranda:Millennium Pharmaceuticals: Employment. Milhollen:Millennium Pharmaceuticals: Employment.

Carfilzomib Platform Study Using The LAGκ-1A Multiple Myeloma Xenograft Model

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4452-4452
Author(s):  
Eric Sanchez ◽  
Mingjie Li ◽  
Suzie Vardanyan ◽  
Jillian Gottlieb ◽  
Kevin Delijani ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Disease Progression ◽  
Tumor Size ◽  
Single Agent ◽  
Xenograft Model ◽  
In Vivo Studies ◽  
Human Igg ◽  
Similar Treatment ◽  
Agent Treatment

Introduction We previously demonstrated that severe combined immunodeficient (SCID) mice bearing the human multiple myeloma (MM) xenograft LAGκ-1A treated with single agent carfilzomib or the alkylating agent (AA) cyclophosphamide (CY) did not show a reduction in tumor growth compared to vehicle-treated mice. In contrast, carfilzomib with CY resulted in a significant decrease in tumor size and IgG levels when compared to mice treated with single agent carfilzomib or CY or vehicle alone. We have also shown that the combination of carfilzomib and another AA, bendamustine, decreased tumor size and IgG levels, when compared to mice treated with single agents or vehicle alone. However, no data is available regarding sequencing of the proteasome inhibitors (PI) carfilzomib or bortezomib with the AA melphalan (MEL). Thus, we used our SCID-hu MM models to evaluate the sequencing of these drugs with MEL. These studies are critical as both PIs are now being used to treat MM. Thus, we evaluated the response, toxicity and survival of animals treated sequentially with these drugs. Methods Each naïve SCID mouse was surgically implanted with a 20 – 40 mm3 MM tumor piece into the left hind limb superficial gluteal muscle. Seven days post–implantation mice were randomized into treatment groups based on human immunoglobulin (Ig) G levels. Carfilzomib stock solution (2 mg/ml) was diluted to 3 mg/kg using 5% dextrose and administered twice weekly on two consecutive days via intravenous (i.v.) injection. Bortezomib stock solution (1 mg/ml) was diluted to 0.25 mg/kg using NaCl and administered twice weekly (Thursdays and Saturdays) via i.v. injection. MEL stock solution (3 mg/ml) was diluted to 1 mg/kg using PBS and administered once weekly via intraperitoneal injection. Mice (n = 10/group) were initially treated with carfilzomib or MEL alone until tumor progression. Progression was defined as an increase in paraprotein equal to or above 25% confirmed on one consecutive assessment. Mice initially treated with carfilzomib were randomized to continue to receive single agent carfilzomib, add in MEL alone or combine it with ongoing carfilzomib, substitute single agent bortezomib, or discontinue treatment altogether. A similar treatment strategy was evaluated with mice treated initially with MEL. At progression, these animals were continued on single agent MEL, carfilzomib added alone or with continuation of MEL, or discontinued treatment. Tumor size was measured using standard calipers and human IgG levels with an ELISA (Bethyl Laboratories, Montgomery, TX). This study was conducted according to protocols approved by the Institutional Animal Care and Use Committee. Results When carfilzomib was administered first, followed by the addition of MEL, a modest nonsignificant reduction in tumor size was observed compared to either drug alone. In addition, substitution of single agent bortezomib for carfilzomib showed no effect on tumor size. However, when MEL was administered first and carfilzomib was added after disease progression, at days 35 and 42 (end of study) post tumor implantation, mice treated with the combination showed a reduction in tumor volume compared to mice that discontinued melphalan (P = 0.0378 and P = 0.0105, respectively) whereas mice treated with carfilzomib alone showed no reduction in tumor size following progression from MEL. Notably, throughout the study there was a trend toward smaller tumors in mice receiving this combination when compared to mice receiving single agent treatment with carfilzomib or MEL alone or vehicle. Similar effects were observed on human IgG levels. Overall, all mice survived combination or single agent treatment with these agents. Conclusions These in vivo studies using our human MM LAGκ–1A SCID–hu model show that animals progressing from initial MEL treatment show a reduction in MM tumor burden when carfilzomib is added to MEL at progression. In contrast, mice progressing from initial carfilzomib treatment did not benefit from the addition of MEL at disease progression. No drug-related deaths occurred in any treatment group. This study demonstrates that using a different MM model (LAGκ-1A), that the PI carfilzomib can produce anti-tumor effects among mice progressing from single-agent MEL treatment, providing further support for the use of this PI as an agent that can help overcome drug resistance in MM. Disclosures: Berenson: Onyx Pharmaceuticals: Consultancy, Honoraria, Research Funding, Speakers Bureau.

ABL001, a Potent Allosteric Inhibitor of BCR-ABL, Prevents Emergence of Resistant Disease When Administered in Combination with Nilotinib in an in Vivo Murine Model of Chronic Myeloid Leukemia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 398-398 ◽  
Author(s):  
Andrew Wylie ◽  
Joseph Schoepfer ◽  
Giuliano Berellini ◽  
Hongbo Cai ◽  
Giorgio Caravatti ◽  
...  
Keyword(s):  
Biomedical Research ◽  
Tumor Regression ◽  
Single Agent ◽  
Point Mutations ◽  
Xenograft Model ◽  
Kinase Domain ◽  
X Ray Crystallography ◽  
N Terminus ◽  
Emergence Of Resistance

Abstract Background: Chronic myelogenous leukemia (CML) and a subset of acute lymphoblastic leukemia (ALL) are caused by the t(9;22)(q34;q11.2) chromosome translocation, resulting in fusion of the BCR and ABL1 genes on the Philadelphia chromosome to encode constitutively active ABL1 kinase. Despite the dramatic progress made over the past decade with tyrosine kinase inhibitors (TKIs) in the treatment of CML, allogeneic stem cell transplant is considered the only proven curative therapy. To achieve cure or benefit from treatment-free remissions with pharmacologically-based therapies, it is estimated that patients will likely need to achieve a sustained reduction in tumor burden of 4 logs (MR4) or deeper (MR4.5). Currently, only 39% and 18% of patients achieve MR4 by 24 months of treatment with single agent nilotinib or imatinib, respectively. Furthermore, for a subset of CML patients and the majority of Ph+ ALL patients, resistance develops to current TKI’s as a result of emergence of point mutations in the ATP site of the kinase domain. ABL001 is a potent, selective BCR-ABL inhibitor that maintains activity across most mutations, including T315I, with a distinct, allosteric mechanism of action which recently entered Phase I development for the treatment of patients with CML and Ph+ ALL. ABL001 was developed to be dosed in combination with nilotinib to provide greater pharmacological coverage of BCR-ABL disease and prevent the emergence of resistance. Methods: Based on X-ray crystallography, NMR and molecular modeling, ABL001 is the result of a structure-guided medicinal chemistry program targeting the myristoyl pocket of the ABL1 kinase. In vitro cell based assays were performed using the Ba/F3 isogenic cell system and a panel of over 300 cell lines. KCL-22 cells were used to develop an in vivo xenograft model to assess the efficacy of ABL001 and the PD marker, pSTAT5, was used to monitor the inhibition of BCR-ABL signaling. Results: In contrast to TKIs that bind to the ATP-site of the ABL1 kinase domain, NMR and X-Ray crystallography studies confirmed that ABL001 binds to a pocket on the BCR-ABL kinase domain that is normally occupied by the myristoylated N-terminus of ABL1. Upon fusion with BCR, this myristoylated N-terminus that serves to autoregulate ABL1 activity is lost. ABL001 functionally mimics the role of the myristoylated N-terminus by occupying its vacant binding site and restores the negative regulation of the kinase activity. Cell proliferation studies demonstrate that ABL001 selectively inhibited the growth of CML and Ph+ ALL cells with potencies ranging from 1-10nM range. In contrast, BCR-ABL-negative cell lines remained unaffected at concentrations 1000-fold higher. With resistance emerging in the clinic to current TKI’s as a result of point mutations in the ATP-site, ABL001 was tested for activity against clinically observed mutations and found to be active in the low nM range. In the KCL-22 mouse xenograft model, ABL001 displayed potent anti-tumor activity with complete tumor regression observed and a clear dose-dependent correlation with pSTAT5 inhibition. The KCL-22 xenograft model was also used to compare the dosing of ABL001 and nilotinib as single agents to dosing a combination of ABL001 and nilotinib. Single agent dosing regimens led to tumor regressions; however, despite continuous dosing, all tumors relapsed within 30-60 days with evidence of point mutations in the resistant tumors. In contrast, animals treated with the combination of ABL001 and nilotinib achieved sustained tumor regression with no evidence of disease relapse either during the 70 days of treatment or for > 150 days after treatment stopped. Conclusion: ABL001 selectively inhibited the proliferation of cells expressing the BCR-ABL fusion gene and was active against clinically important mutations that arise with current TKI therapy in CML. In an in vivo model of CML, the combination of ABL001 and nilotinib resulted in complete and sustained tumor regression with no evidence of disease relapse. These results provide proof-of-principle that simultaneous targeting of the myristoyl pocket and ATP-pocket by ABL001 and nilotinib, respectively, promotes a more sustained overall efficacy and prevents the emergence of resistance via acquisition of point mutations in the respective binding sites. ABL001 is currently being evaluated in a Phase 1 study in patients with CML and Ph+ ALL. Disclosures Wylie: Novartis Institutes for Biomedical Research, Inc: Employment. Schoepfer:Novartis Institutes for Biomedical Research: Employment. Berellini:Novartis Institutes for Biomedical Research: Employment. Cai:Novartis Institutes for Biomedical Research: Employment. Caravatti:Novartis Institutes for Biomedical Research: Employment. Cotesta:Novartis Institues for Biomedical Research: Employment. Dodd:Novartis Institutes for Biomedical Research: Employment. Donovan:Novartis Institutes for Biomedical Research: Employment. Erb:Novartis Institutes for Biomedical Research: Employment. Furet:Novartis Institutes for Biomedical Research: Employment. Gangal:Novartis Institutes for Biomedical Research: Employment. Grotzfeld:Novartis Institutes for Biomedical Research: Employment. Hassan:Novartis Institutes for Biomedical Research: Employment. Hood:Novartis Institutes for Biomedical Research: Employment. Iyer:Novartis Institutes for Biomedical Research: Employment. Jacob:Novartis Institutes for Biomedical Research: Employment. Jahnke:Novartis Institutes for Biomedical Research: Employment. Lombardo:Novartis Institutes for Biomedical Research: Employment. Loo:Novartis Institutes for Biomedical Research: Employment. Manley:Novartis Institutes for Biomedical Research: Employment. Marzinzik:Novartis Institutes for Biomedical Research: Employment. Palmer:Novartis Institutes for Biomedical Research: Employment. Pelle:Novartis Institutes for Biomedical Research: Employment. Salem:Novartis Institutes for Biomedical Research: Employment. Sharma:Novartis Institutes for Biomedical Research: Employment. Thohan:Novartis Institutes for Biomedical Research: Employment. Zhu:Novartis Institutes for Biomedical Research: Employment. Keen:Novartis Institutes for Biomedical Research: Employment. Petruzzelli:Novartis Institutes for Biomedical Research: Employment. Vanasse:Novartis: Employment, Equity Ownership. Sellers:Novartis: Employment.

scholarly journals The CDK9 Inhibitor, Alvocidib, Potentiates the Non-Clinical Activity of Azacytidine or Decitabine in an MCL-1-Dependent Fashion, Supporting Clinical Exploration of a Decitabine and Alvocidib Combination

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4355-4355
Author(s):  
Wontak Kim ◽  
Clifford Whatcott ◽  
Adam Siddiqui-Jain ◽  
Stephen Anthony ◽  
David J. Bearss ◽  
...  
Keyword(s):  
Protein Expression ◽  
Cell Viability ◽  
Single Agent ◽  
Xenograft Model ◽  
Complete Response ◽  
Tumor Growth Inhibition ◽  
Phase 2 ◽  
Phase 1B ◽  
Cdk9 Inhibitor

Abstract The hypomethylating agents (HMAs) azacytidine and decitabine exert biological activity via two distinct mechanisms, namely, DNA damage and inhibition of DNA methyltransferases. Azacytidine and decitabine are indicated in the treatment of patients with myelodysplastic syndromes (MDS). As a result of DNA methyltransferase inhibition, it is hypothesized that HMAs may function by inducing re-expression of key pro-apoptotic proteins such as NOXA, which sequesters the anti-apoptotic protein MCL-1, preventing its association with the mitochondrial pore-forming proteins BAX/BAK. Activity of the potent CDK9 inhibitor, alvocidib, is largely driven by targeting of CDK9-dependent MCL-1 expression. Alvocidib is under active clinical investigation, but has also has demonstrated high complete response rates in newly diagnosed AML patients, particularly when administered as part of a cytarabine and mitoxantrone containing regimen (ACM regimen). Given the dual NOXA/MCL-1-targeting ability of combining alvocidib and azacytidine or decitabine, the combination may synergize therapeutically in the treatment of non-clinical models of AML or MDS by means of transcriptional induction of NOXA and repression of MCL-1 expression. Cell viability and induction of apoptosis was assessed following treatment with alvocidib, azacytidine, and decitabine in cells using the Celltiter-Glo and Caspase-Glo assays. Gene expression changes following treatment were assessed using quantitative RT-PCR. Protein expression changes with treatment were also measured using standard immunoblotting technique. To assess the in vivo anti-tumor activity of these compounds, xenograft studies in the MOLM13 and additional models of MDS, exploring sequencing and scheduling of alvocidib administration with HMAs, were performed. Treatment of AML cell lines with alvocidib inhibited both mRNA and protein expression of MCL-1 in a time and concentration-dependent fashion. Pre-treatment of cells with alvocidib, to repress MCL-1 expression prior to azacytidine treatment, reduced the azacytidine cell viability EC50 more than 2.5-fold, from 1.8 µM to 0.6 µM in MV4-11 cells. The alvocidib/azacytidine combination also resulted in synergistic increases in caspase activity relative to either single agent within the combination, at multiple dose levels. The combination of azacytidine or decitabine with alvocidib was active in the MOLM13 xenograft model, yielding up to 65.7 or 91.1% tumor growth inhibition (%TGI) in the azacytidine or decitabine combination, respectively. Taken together, the in vitro and in vivo studies indicated that decitabine was more effective at re-expressing NOXA and potentiating alvocidib activity compared to azacytidine. These non-clinical data suggest that an alvocidib/HMA combination may constitute a viable therapeutic regimen whose rationale focuses on hypertargeting of NOXA/MCL-1. Based on these non-clinical results, a Phase 1b/2 clinical study of alvocidib administered in sequence after decitabine in patients with intermediate to high risk MDS is being conducted (Zella 102). Patients will be enrolled in cohorts of 3-6 patients with decitabine administered as a 1-hour IV infusion daily on days 1 to 5 at a dose of 20 mg/m2 followed by a single alvocidib treatment on day 8 as a loading dose over 30 minutes followed by a 4-hour infusion. Treatment will be repeated every 28 days until disease progression or unacceptable toxicity. Enrollment will include MDS patients (Phase 1b) with previously untreated MDS and patients who received fewer than six (6) cycles of previous HMAs, as well as (Phase 2) untreated patients with de novo or secondary MDS. The primary objective is to determine the maximum tolerated dose and recommended Phase 2 dose of alvocidib when administered in sequence with decitabine. Key Phase 2 endpoints will include complete response rate and improvement in transfusion dependency. Disclosures Kim: Tolero Pharmaceuticals, Inc: Employment. Whatcott:Tolero Pharmaceuticals, Inc: Employment. Siddiqui-Jain:Tolero Pharmaceuticals, Inc: Employment. Anthony:Tolero Pharmaceuticals, Inc: Employment. Bearss:Tolero Pharmaceuticals, Inc: Employment. Warner:Tolero Pharmaceuticals: Employment.

scholarly journals Upregulation of ERK-EGR1-heparanase axis by HDAC inhibitors provides targets for rational therapeutic intervention in synovial sarcoma

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Cinzia Lanzi ◽  
Enrica Favini ◽  
Laura Dal Bo ◽  
Monica Tortoreto ◽  
Noemi Arrighetti ◽  
...  
Keyword(s):  
Synovial Sarcoma ◽  
Cell Response ◽  
Histone Deacetylases ◽  
Molecular Mechanisms ◽  
Combined Treatment ◽  
Single Agent ◽  
Hdac Inhibitors ◽  
Xenograft Model

Abstract Background Synovial sarcoma (SS) is an aggressive soft tissue tumor with limited therapeutic options in advanced stage. SS18-SSX fusion oncogenes, which are the hallmarks of SS, cause epigenetic rewiring involving histone deacetylases (HDACs). Promising preclinical studies supporting HDAC targeting for SS treatment were not reflected in clinical trials with HDAC inhibitor (HDACi) monotherapies. We investigated pathways implicated in SS cell response to HDACi to identify vulnerabilities exploitable in combination treatments and improve the therapeutic efficacy of HDACi-based regimens. Methods Antiproliferative and proapoptotic effects of the HDACi SAHA and FK228 were examined in SS cell lines in parallel with biochemical and molecular analyses to bring out cytoprotective pathways. Treatments combining HDACi with drugs targeting HDACi-activated prosurvival pathways were tested in functional assays in vitro and in a SS orthotopic xenograft model. Molecular mechanisms underlying synergisms were investigated in SS cells through pharmacological and gene silencing approaches and validated by qRT-PCR and Western blotting. Results SS cell response to HDACi was consistently characterized by activation of a cytoprotective and auto-sustaining axis involving ERKs, EGR1, and the β-endoglycosidase heparanase, a well recognized pleiotropic player in tumorigenesis and disease progression. HDAC inhibition was shown to upregulate heparanase by inducing expression of the positive regulator EGR1 and by hampering negative regulation by p53 through its acetylation. Interception of HDACi-induced ERK-EGR1-heparanase pathway by cell co-treatment with a MEK inhibitor (trametinib) or a heparanase inhibitor (SST0001/roneparstat) enhanced antiproliferative and pro-apoptotic effects. HDAC and heparanase inhibitors had opposite effects on histone acetylation and nuclear heparanase levels. The combination of SAHA with SST0001 prevented the upregulation of ERK-EGR1-heparanase induced by the HDACi and promoted caspase-dependent cell death. In vivo, the combined treatment with SAHA and SST0001 potentiated the antitumor efficacy against the CME-1 orthotopic SS model as compared to single agent administration. Conclusions The present study provides preclinical rationale and mechanistic insights into drug combinatory strategies based on the use of ERK pathway and heparanase inhibitors to improve the efficacy of HDACi-based antitumor therapies in SS. The involvement of classes of agents already clinically available, or under clinical evaluation, indicates the transferability potential of the proposed approaches.

scholarly journals Aberrations of growth factors as biomarkers of cancer progression

2005 ◽  
Vol 13 (3-4) ◽  
pp. 121-123 ◽  
Author(s):  
Vesna Ivanovic
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Signaling Pathways ◽  
Cancer Progression ◽  
Transforming Growth Factor ◽  
Egfr Inhibitors ◽  
Egfr Mutations ◽  
Genomic Markers ◽  
Somatic Alterations ◽  
Prostate Cancers

Cell proliferation and growth are regulated by a complex network of growth factor and growth inhibitorinitiated signal transduction pathways. The disruption of these signaling pathways through genetic, epigenetic, or somatic alterations is a major area of cancer research. Increasing evidence indicates that oncogenic activation of growth factors and their receptor proteins occur through mutations (oncoproteins) that lead to constitutive activation of the signaling pathways, thus providing the grounds for putative prognostic marker(s) and potential target(s) for treatment of various cancers. Over the past few years, the study of genomics has revealed the gene expression signatures for many malignancies. Present communication outlines literature survey on genomic molecular markers of breast, lung, and prostate cancers. Reassuringly, the dominant genomic markers of these malignancies include oncoproteins and provide a support for their clinical validity as cancer targets. More specifically, this article reviews recent advances in clinical targeting of these malignancies by two types of growth factor/receptors, namely transforming growth factor-? (TGF-?), and EGFR subfamily of tyrosine kinase receptors including ErbB2. Overexpression of these proteins has been demonstrated in patients with cancer progression and correlated with poor prognosis, increased frequency of metastasis and death. In addition, EGFR and ErbB2 inhibitors have been used in targeted therapy of lung and breast cancer, respectively. Recent investigations of lung cancer have uncovered that EGFR inhibitors have their greatest effect in patients with EGFR somatic mutations thus raising a possibility that EGFR mutations may be a molecular predictors of sensitivity to EGFR inhibitors.

scholarly journals Developing a xenograft model of human vasculature in the mouse ear pinna

2019 ◽  
Author(s):  
Gavin R. Meehan ◽  
Hannah E. Scales ◽  
Rowland Osii ◽  
Mariana De Niz ◽  
Jennifer C. Lawton ◽  
...  
Keyword(s):  
Drug Evaluation ◽  
Multiphoton Microscopy ◽  
Subcutaneous Fat ◽  
Xenograft Model ◽  
Circulatory System ◽  
Recipient Mouse ◽  
Cellular Recruitment ◽  
Immunocompromised Mice

AbstractHumanised xenograft models allow for the analysis of human tissue within a physiological environment in vivo. However, current models often rely on the angiogenesis and ingrowth of recipient vasculature to perfuse tissues, preventing analysis of biological processes and diseases involving human blood vessels. This limits the effectiveness of xenografts in replicating human physiology and may lead to issues with translating findings into human research.We have designed a xenograft model of human vasculature to address this issue. Human subcutaneous fat was cultured in vitro to promote blood vessel outgrowth prior to implantation into immunocompromised mice. We demonstrate that implants survived, retained human vasculature and anastomosed with the circulatory system of the recipient mouse. Significantly, by performing transplants into the ear pinna, this system enabled intravital observation of xenografts by multiphoton microscopy, allowing us to visualise the steps leading to vascular cytoadherence of erythrocytes infected with the human parasite Plasmodium falciparum.This model represents a useful tool for imaging the interactions that occur within human tissues in vivo and permits visualization of blood flow and cellular recruitment in a system which is amenable to intervention for various studies in basic biology together with drug evaluation and mechanism of action studies.

scholarly journals Loss of p16INK4a in neuroblastoma cells induces shift to an immature state with mesenchymal characteristics and increases sensitivity to EGFR inhibitors

2021 ◽  
Author(s):  
Nil A. Schubert ◽  
Sander R. van Hooff ◽  
Linda Schild ◽  
Kimberley Ober ◽  
Marjolein Hortensius ◽  
...  
Keyword(s):  
Human Cancer ◽  
Neuroblastoma Cells ◽  
Recurrent Event ◽  
Egfr Inhibitors ◽  
Pathway Activation ◽  
Cdkn2a Deletion ◽  
Genomic Aberrations ◽  
Gene Transcripts ◽  
Phenotypic Shift

Homozygous inactivation of the CDKN2A locus is one of the most common genomic aberrations in human cancer. The locus codes for two unrelated and distinctly regulated proteins: p14ARF and p16INK4a, which inhibit MDM2 and CDK4/6, respectively. Loss of CDKN2A is also a recurrent event in relapsed neuroblastoma, a childhood tumour that arises from neural crest cells. To examine the consequences of the loss of the two distinct gene transcripts in neuroblastoma, we used the CRISPR-Cas9 system to knockout p14, p16 and p14+p16 in SY5Y cells. RNA sequencing of the transcriptome revealed a striking shift towards an immature Schwann cell precursor-like phenotype with mesenchymal characteristics, specifically in the p16 and p14+p16 knockouts. High-throughput drug screening of p16 and p14+p16 knockout clones identified a large in increase in sensitivity to EGFR inhibitors. On protein level, we were able to confirm that EGFR pathway activation is higher in p14+p16 knockout cells and that treatment with the EGFR inhibitor afatinib resulted in higher levels of apoptosis. Afatinib also reduced tumour growth in vivo in xenografts transplanted with p14+p16 knockout SY5Y cells. Overall, our study suggests that CDKN2A deletion in neuroblastoma relates to a phenotypic shift towards a more progenitor like state and increases sensitivity to EGFR inhibitors.

A phase II study of two dosing regimens of GSK 1363089 (GSK089), a dual MET/VEGFR2 inhibitor, in patients (pts) with papillary renal carcinoma (PRC)

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 5103-5103 ◽  
Author(s):  
R. Srinivasan ◽  
W. M. Linehan ◽  
U. Vaishampayan ◽  
T. Logan ◽  
S. M. Shankar ◽  
...  
Keyword(s):  
Renal Carcinoma ◽  
Single Agent ◽  
Activating Mutations ◽  
Best Response ◽  
Pathway Activation ◽  
Molecule Inhibitor ◽  
Dosing Regimens ◽  
Trisomy 7 ◽  
Pharmacodynamic Markers ◽  
Anti Tumor Activity

5103 Background: GSK089 is a potent, orally available small molecule inhibitor of MET and VEGFR2. Activating mutations and/or amplifications in MET have been described in pts with PRC. Two of 4 PRC pts treated with intermittent dosing of GSK089 on a Phase I study sustained partial responses (PR) for 1 and > 3 years respectively. The aim of the current study is to evaluate the efficacy, safety and tolerability of 2 dosing regimens of GSK089 as a single agent in pts with advanced sporadic PRC (SPRC) or hereditary PRC (HPRC). Methods: Adults with advanced PRC are enrolled in 2 cohorts with different dosing schedules of GSK089: cohort 1) 240 mg/day on days 1–5 of every 14 days (5-on/9-off); cohort 2) 80 mg daily. Pts are stratified based on status of MET-pathway activation (activating MET mutation, MET [7q31] amplification, or trisomy 7). The primary endpoint is RECIST response rate, assessed every 8 weeks. Plasma markers reflecting potential effects of MET inhibition and anti-VEGF therapy are analyzed. Results: As of December 15, 2008, 37 pts were enrolled in the 5-on/9-off cohort (19 with MET activation including 5 HPRC, 18 SPRC without MET activation or unknown MET status), and 16 pts in the daily dosing cohort (2 with HPRC, 14 SPRC with unknown MET status). Enrollment is ongoing in cohort 2. In cohort 1, of the 35 evaluable pts, 4 pts (2 HPRC and 2 SPRC) had confirmed PRs and 27 had stable disease (SD) as best response with 6 ≥12mo, 3 ≥ 9mo and 3 ≥ 6mo. Four of 5 HPRC pts (1 not evaluated) had shrinkage (15–53%) in all measurable tumors. Twenty-three SPRC pts had shrinkage (2–58%) in the sum of measurable tumors. In cohort 2, of the 9 evaluable pts, 2 (both SPRC) had confirmed PRs, and 7 had SD. The most frequent adverse events (AEs) associated with GSK089 were fatigue, hypertension, nausea, vomiting, diarrhea, and increased ALT/AST, primarily grades 1 and 2. Preliminary results from cohort 1 indicated that plasma shed Met (sMET) and VEGF increased and sVEGFR2 decreased after 2 cycles with changes maintained after 4 cycles. Conclusions: GSK089 is well tolerated and demonstrates anti-tumor activity in pts with PRC with both 5-on/9-off and daily dosing. VEGF, sVEGFR2, and sMET are promising pharmacodynamic markers for biological activity of GSK089. [Table: see text]

Efficacy of vemurafenib (V), a selective V600EBRAF inhibitor, as monotherapy or in combination with erlotinib (Erl) or erbitux (Erb) and irinotecan (Iri) doublets and triplets in a colorectal cancer (CRC) xenograft model.

2012 ◽  
Vol 30 (4_suppl) ◽  
pp. 494-494
Author(s):  
Brian Higgins ◽  
Kenneth Daniel Kolinsky ◽  
Kathleen Schostack ◽  
Gideon Bollag ◽  
Richard J. Lee ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Mapk Pathway ◽  
Single Agent ◽  
Xenograft Model ◽  
Optimal Dose ◽  
Tumor Growth Inhibition ◽  
Egfr Inhibition ◽  
Final Study ◽  
Molecule Inhibitor ◽  
Better Than

494 Background: B-Raf mutations, particularly at V600 occur in 10% of CRCs resulting in constitutive activation of the MAPK pathway. V (RG7204, PLX4032) is a first-in-class, V600B-Raf-selective small molecule inhibitor previously shown to potentiate anti-tumor effects in the V600E CRC xenograft model HT29 in combination (combo) with capecitabine ± bevacizumab (ASCO GI, 2008). V600E CRC respond poorly to EGFR inhibition (EGFRi) both preclinically and clinically. We aimed to determine whether antitumor activity could be potentiated by combining V with EGFRi. Methods: The monotherapy (mono) activities of V, Erl, Erb and Iri were compared to combo of these agents in the HT29 model. V was tested as a mono at its optimal dose (OD), Erl was tested at its MTD or 2/3 MTD, and a combo of V OD + 2/3 MTD Erl were tested. V was subsequently tested as mono or combo at the OD and suboptimal-OD with OD Erb. A final study included Iri as mono, doublets of Iri + V or Erb, and triplet combo of Iri, V, and Erb. Results: Tumor growth inhibition (TGI) and increase in life span (ILS) for combo of OD V + 2/3 MTD Erl was superior to all mono arms. TGI in mono arms was equivalent for V, Erb and Iri. ILS was better for V vs Iri and Erb mono, while Iri vs Erb ILS were equivalent. TGI and ILS for Iri + Erb doublet was equivalent to V mono. Otherwise, TGI and ILS in all other doublets and triplets were superior to mono groups. TGI in V + Erb and V + Iri were equivalent, but ILS was better for V + Iri. TGI and ILS for V + Iri was better than Iri + Erb. TGI in V + Erb was better than Iri + Erb, but ILS was equivalent. TGI in the triplet was superior to all doublets except V + Erb, however ILS was superior to all doublets tested. Conclusions: V potentiates anti-tumor activity in a V600E CRC model when used in combo with Erl, Erb and Iri. Although a V + Erb doublet provided impressive TGI equivalent to a triplet with Iri, the triplet yielded sustained antitumor activity as demonstrated by a significant increase in survival as compared to the doublet. Combo with V may afford V600E CRC patients a differential response to what is seen traditionally with single agent EGFi and is worthy of clinical exploration.

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