Publications by authors named "Audrey Kauffmann"

35 Publications

The Discovery of SWI/SNF Chromatin Remodeling Activity as a Novel and Targetable Dependency in Uveal Melanoma.

Mol Cancer Ther 2020 10 3;19(10):2186-2195. Epub 2020 Aug 3.

Novartis Institutes for Biomedical Research, Cambridge, Massachusetts.

Uveal melanoma is a rare and aggressive cancer that originates in the eye. Currently, there are no approved targeted therapies and very few effective treatments for this cancer. Although activating mutations in the G protein alpha subunits, and , are key genetic drivers of the disease, few additional drug targets have been identified. Recently, studies have identified context-specific roles for the mammalian SWI/SNF chromatin remodeling complexes (also known as BAF/PBAF) in various cancer lineages. Here, we find evidence that the SWI/SNF complex is essential through analysis of functional genomics screens and further validation in a panel of uveal melanoma cell lines using both genetic tools and small-molecule inhibitors of SWI/SNF. In addition, we describe a functional relationship between the SWI/SNF complex and the melanocyte lineage-specific transcription factor Microphthalmia-associated Transcription Factor, suggesting that these two factors cooperate to drive a transcriptional program essential for uveal melanoma cell survival. These studies highlight a critical role for SWI/SNF in uveal melanoma, and demonstrate a novel path toward the treatment of this cancer.
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http://dx.doi.org/10.1158/1535-7163.MCT-19-1013DOI Listing
October 2020

Genetic heterogeneity and clonal evolution during metastasis in breast cancer patient-derived tumor xenograft models.

Comput Struct Biotechnol J 2020 31;18:323-331. Epub 2020 Jan 31.

Disease Area Oncology, Novartis Institutes for BioMedical Research, Basel, Switzerland.

Genetic heterogeneity within a tumor arises by clonal evolution, and patients with highly heterogeneous tumors are more likely to be resistant to therapy and have reduced survival. Clonal evolution also occurs when a subset of cells leave the primary tumor to form metastases, which leads to reduced genetic heterogeneity at the metastatic site. Although this process has been observed in human cancer, experimental models which recapitulate this process are lacking. Patient-derived tumor xenografts (PDX) have been shown to recapitulate the patient's original tumor's intra-tumor genetic heterogeneity, as well as its genomics and response to treatment, but whether they can be used to model clonal evolution in the metastatic process is currently unknown. Here, we address this question by following genetic changes in two breast cancer PDX models during metastasis. First, we discovered that mouse stroma can be a confounding factor in assessing intra-tumor heterogeneity by whole exome sequencing, thus we developed a new bioinformatic approach to correct for this. Finally, in a spontaneous, but not experimental (tail-vein) metastasis model we observed a loss of heterogeneity in PDX metastases compared to their orthotopic "primary" tumors, confirming that PDX models can faithfully mimic the clonal evolution process undergone in human patients during metastatic spreading.
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http://dx.doi.org/10.1016/j.csbj.2020.01.008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7026725PMC
January 2020

PAX8 activates metabolic genes via enhancer elements in Renal Cell Carcinoma.

Nat Commun 2019 08 20;10(1):3739. Epub 2019 Aug 20.

Disease Area Oncology, Novartis Institute for Biomedical Research, Basel, Switzerland.

Transcription factor networks shape the gene expression programs responsible for normal cell identity and pathogenic state. Using Core Regulatory Circuitry analysis (CRC), we identify PAX8 as a candidate oncogene in Renal Cell Carcinoma (RCC) cells. Validation of large-scale functional genomic screens confirms that PAX8 silencing leads to decreased proliferation of RCC cell lines. Epigenomic analyses of PAX8-dependent cistrome demonstrate that PAX8 largely occupies active enhancer elements controlling genes involved in various metabolic pathways. We selected the ferroxidase Ceruloplasmin (CP) as an exemplary gene to dissect PAX8 molecular functions. PAX8 recruits histone acetylation activity at bound enhancers looping onto the CP promoter. Importantly, CP expression correlates with sensitivity to PAX8 silencing and identifies a subset of RCC cases with poor survival. Our data identifies PAX8 as a candidate oncogene in RCC and provides a potential biomarker to monitor its activity.
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http://dx.doi.org/10.1038/s41467-019-11672-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6702156PMC
August 2019

FGF401, A First-In-Class Highly Selective and Potent FGFR4 Inhibitor for the Treatment of FGF19-Driven Hepatocellular Cancer.

Mol Cancer Ther 2019 12 13;18(12):2194-2206. Epub 2019 Aug 13.

Novartis Institutes for Biomedical Research, Oncology Disease Area, Basel, Switzerland.

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and it is the third leading cause of cancer-related deaths worldwide. Recently, aberrant signaling through the FGF19/FGFR4 axis has been implicated in HCC. Here, we describe the development of FGF401, a highly potent and selective, first in class, reversible-covalent small-molecule inhibitor of the kinase activity of FGFR4. FGF401 is exquisitely selective for FGFR4 versus the other FGFR paralogues FGFR1, FGFR2, FGFR3, and all other kinases in the kinome. FGF401 has excellent drug-like properties showing a robust pharmacokinetic/pharmacodynamics/efficacy relationship, driven by a fraction of time above the phospho-FGFR4 IC value. FGF401 has remarkable antitumor activity in mice bearing HCC tumor xenografts and patient-derived xenograft models that are positive for FGF19, FGFR4, and KLB. FGF401 is the first FGFR4 inhibitor to enter clinical trials, and a phase I/II study is currently ongoing in HCC and other solid malignancies.
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http://dx.doi.org/10.1158/1535-7163.MCT-18-1291DOI Listing
December 2019

Next-generation characterization of the Cancer Cell Line Encyclopedia.

Nature 2019 05 8;569(7757):503-508. Epub 2019 May 8.

Broad Institute of Harvard and MIT, Cambridge, MA, USA.

Large panels of comprehensively characterized human cancer models, including the Cancer Cell Line Encyclopedia (CCLE), have provided a rigorous framework with which to study genetic variants, candidate targets, and small-molecule and biological therapeutics and to identify new marker-driven cancer dependencies. To improve our understanding of the molecular features that contribute to cancer phenotypes, including drug responses, here we have expanded the characterizations of cancer cell lines to include genetic, RNA splicing, DNA methylation, histone H3 modification, microRNA expression and reverse-phase protein array data for 1,072 cell lines from individuals of various lineages and ethnicities. Integration of these data with functional characterizations such as drug-sensitivity, short hairpin RNA knockdown and CRISPR-Cas9 knockout data reveals potential targets for cancer drugs and associated biomarkers. Together, this dataset and an accompanying public data portal provide a resource for the acceleration of cancer research using model cancer cell lines.
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http://dx.doi.org/10.1038/s41586-019-1186-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6697103PMC
May 2019

Dose and Schedule Determine Distinct Molecular Mechanisms Underlying the Efficacy of the p53-MDM2 Inhibitor HDM201.

Cancer Res 2018 11 22;78(21):6257-6267. Epub 2018 Aug 22.

Disease Area Oncology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts.

Activation of p53 by inhibitors of the p53-MDM2 interaction is being pursued as a therapeutic strategy in p53 wild-type cancers. Here, we report distinct mechanisms by which the novel, potent, and selective inhibitor of the p53-MDM2 interaction HDM201 elicits therapeutic efficacy when applied at various doses and schedules. Continuous exposure of HDM201 led to induction of p21 and delayed accumulation of apoptotic cells. By comparison, high-dose pulses of HDM201 were associated with marked induction of PUMA and a rapid onset of apoptosis. shRNA screens identified PUMA as a mediator of the p53 response specifically in the pulsed regimen. Consistent with this, the single high-dose HDM201 regimen resulted in rapid and marked induction of PUMA expression and apoptosis together with downregulation of Bcl-xL Knockdown of Bcl-xL was identified as the top sensitizer to HDM201 , and Bcl-xL was enriched in relapsing tumors from mice treated with intermittent high doses of HDM201. These findings define a regimen-dependent mechanism by which disruption of MDM2-p53 elicits therapeutic efficacy when given with infrequent dosing. In an ongoing HDM201 trial, the observed exposure-response relationship indicates that the molecular mechanism elicited by pulse dosing is likely reproducible in patients. These data support the clinical comparison of daily and intermittent regimens of p53-MDM2 inhibitors. Pulsed high doses versus sustained low doses of the p53-MDM2 inhibitor HDM201 elicit a proapoptotic response from wild-type p53 cancer cells, offering guidance to current clinical trials with this and other drugs that exploit the activity of p53. .
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http://dx.doi.org/10.1158/0008-5472.CAN-18-0338DOI Listing
November 2018

Correction of copy number induced false positives in CRISPR screens.

PLoS Comput Biol 2018 07 19;14(7):e1006279. Epub 2018 Jul 19.

Novartis Institutes for Biomedical Research, Basel, Switzerland.

Cell autonomous cancer dependencies are now routinely identified using CRISPR loss-of-function viability screens. However, a bias exists that makes it difficult to assess the true essentiality of genes located in amplicons, since the entire amplified region can exhibit lethal scores. These false-positive hits can either be discarded from further analysis, which in cancer models can represent a significant number of hits, or methods can be developed to rescue the true-positives within amplified regions. We propose two methods to rescue true positive hits in amplified regions by correcting for this copy number artefact. The Local Drop Out (LDO) method uses the relative lethality scores within genomic regions to assess true essentiality and does not require additional orthogonal data (e.g. copy number value). LDO is meant to be used in screens covering a dense region of the genome (e.g. a whole chromosome or the whole genome). The General Additive Model (GAM) method models the screening data as a function of the known copy number values and removes the systematic effect from the measured lethality. GAM does not require the same density as LDO, but does require prior knowledge of the copy number values. Both methods have been developed with single sample experiments in mind so that the correction can be applied even in smaller screens. Here we demonstrate the efficacy of both methods at removing the copy number effect and rescuing hits from some of the amplified regions. We estimate a 70-80% decrease of false positive hits with either method in regions of high copy number compared to no correction.
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http://dx.doi.org/10.1371/journal.pcbi.1006279DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6067744PMC
July 2018

Project DRIVE: A Compendium of Cancer Dependencies and Synthetic Lethal Relationships Uncovered by Large-Scale, Deep RNAi Screening.

Cell 2017 Jul;170(3):577-592.e10

Novartis Institutes for Biomedical Research, Oncology Disease Area, Basel 4002, Switzerland; Cambridge, MA 02139, USA; and Emeryville, CA 94608, USA.

Elucidation of the mutational landscape of human cancer has progressed rapidly and been accompanied by the development of therapeutics targeting mutant oncogenes. However, a comprehensive mapping of cancer dependencies has lagged behind and the discovery of therapeutic targets for counteracting tumor suppressor gene loss is needed. To identify vulnerabilities relevant to specific cancer subtypes, we conducted a large-scale RNAi screen in which viability effects of mRNA knockdown were assessed for 7,837 genes using an average of 20 shRNAs per gene in 398 cancer cell lines. We describe findings of this screen, outlining the classes of cancer dependency genes and their relationships to genetic, expression, and lineage features. In addition, we describe robust gene-interaction networks recapitulating both protein complexes and functional cooperation among complexes and pathways. This dataset along with a web portal is provided to the community to assist in the discovery and translation of new therapeutic approaches for cancer.
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http://dx.doi.org/10.1016/j.cell.2017.07.005DOI Listing
July 2017

Resistance mechanisms to TP53-MDM2 inhibition identified by in vivo piggyBac transposon mutagenesis screen in an Arf mouse model.

Proc Natl Acad Sci U S A 2017 03 6;114(12):3151-3156. Epub 2017 Mar 6.

Oncology Disease Area, Novartis Institutes for BioMedical Research, 4056 Basel, Switzerland.

Inhibitors of double minute 2 protein (MDM2)-tumor protein 53 (TP53) interaction are predicted to be effective in tumors in which the gene is wild type, by preventing TP53 protein degradation. One such setting is represented by the frequent deletion in human cancer that, through inactivation of , activates MDM2 protein, which in turn degrades TP53 tumor suppressor. Here we used piggyBac (PB) transposon insertional mutagenesis to anticipate resistance mechanisms occurring during treatment with the MDM2-TP53 inhibitor HDM201. Constitutive PB mutagenesis in mice provided a collection of spontaneous tumors with characterized insertional genetic landscapes. Tumors were allografted in large cohorts of mice to assess the pharmacologic effects of HDM201. Sixteen out of 21 allograft models were sensitive to HDM201 but ultimately relapsed under treatment. A comparison of tumors with acquired resistance to HDM201 and untreated tumors identified 87 genes that were differentially and significantly targeted by the PB transposon. Resistant tumors displayed a complex clonality pattern suggesting the emergence of several resistant subclones. Among the most frequent alterations conferring resistance, we observed somatic and insertional loss-of-function mutations in transformation-related protein 53 () in 54% of tumors and transposon-mediated gain-of-function alterations in B-cell lymphoma-extra large (), , and two family members, resulting in expression of the TP53 dominant negative truncations and Enhanced BCL-xL and MDM4 protein expression was confirmed in resistant tumors, as well as in HDM201-resistant patient-derived tumor xenografts. Interestingly, concomitant inhibition of MDM2 and BCL-xL demonstrated significant synergy in p53 wild-type cell lines in vitro. Collectively, our findings identify several potential mechanisms by which wild-type tumors may escape MDM2-targeted therapy.
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http://dx.doi.org/10.1073/pnas.1620262114DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5373361PMC
March 2017

CRISPR Screens Provide a Comprehensive Assessment of Cancer Vulnerabilities but Generate False-Positive Hits for Highly Amplified Genomic Regions.

Cancer Discov 2016 08 3;6(8):900-13. Epub 2016 Jun 3.

Oncology Disease Area, Novartis Institutes for Biomedical Research, Cambridge, Massachusetts.

Unlabelled: CRISPR/Cas9 has emerged as a powerful new tool to systematically probe gene function. We compared the performance of CRISPR to RNAi-based loss-of-function screens for the identification of cancer dependencies across multiple cancer cell lines. CRISPR dropout screens consistently identified more lethal genes than RNAi, implying that the identification of many cellular dependencies may require full gene inactivation. However, in two aneuploid cancer models, we found that all genes within highly amplified regions, including nonexpressed genes, scored as lethal by CRISPR, revealing an unanticipated class of false-positive hits. In addition, using a CRISPR tiling screen, we found that sgRNAs targeting essential domains generate the strongest lethality phenotypes and thus provide a strategy to rapidly define the protein domains required for cancer dependence. Collectively, these findings not only demonstrate the utility of CRISPR screens in the identification of cancer-essential genes, but also reveal the need to carefully control for false-positive results in chromosomally unstable cancer lines.

Significance: We show in this study that CRISPR-based screens have a significantly lower false-negative rate compared with RNAi-based screens, but have specific liabilities particularly in the interrogation of regions of genome amplification. Therefore, this study provides critical insights for applying CRISPR-based screens toward the systematic identification of new cancer targets. Cancer Discov; 6(8); 900-13. ©2016 AACR.See related commentary by Sheel and Xue, p. 824See related article by Aguirre et al., p. 914This article is highlighted in the In This Issue feature, p. 803.
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http://dx.doi.org/10.1158/2159-8290.CD-16-0178DOI Listing
August 2016

Maximizing the Efficacy of MAPK-Targeted Treatment in PTENLOF/BRAFMUT Melanoma through PI3K and IGF1R Inhibition.

Cancer Res 2016 Jan 17;76(2):390-402. Epub 2015 Nov 17.

Novartis Institutes for Biomedical Research (NIBR), Disease Area Oncology, Basel, Switzerland.

The introduction of MAPK pathway inhibitors paved the road for significant advancements in the treatment of BRAF-mutant (BRAF(MUT)) melanoma. However, even BRAF/MEK inhibitor combination therapy has failed to offer a curative treatment option, most likely because these pathways constitute a codependent signaling network. Concomitant PTEN loss of function (PTEN(LOF)) occurs in approximately 40% of BRAF(MUT) melanomas. In this study, we sought to identify the nodes of the PTEN/PI3K pathway that would be amenable to combined therapy with MAPK pathway inhibitors for the treatment of PTEN(LOF)/BRAF(MUT) melanoma. Large-scale compound sensitivity profiling revealed that PTEN(LOF) melanoma cell lines were sensitive to PI3Kβ inhibitors, albeit only partially. An unbiased shRNA screen (7,500 genes and 20 shRNAs/genes) across 11 cell lines in the presence of a PI3Kβ inhibitor identified an adaptive response involving the IGF1R-PI3Kα axis. Combined inhibition of the MAPK pathway, PI3Kβ, and PI3Kα or insulin-like growth factor receptor 1 (IGF1R) synergistically sustained pathway blockade, induced apoptosis, and inhibited tumor growth in PTEN(LOF)/BRAF(MUT) melanoma models. Notably, combined treatment with the IGF1R inhibitor, but not the PI3Kα inhibitor, failed to elevate glucose or insulin signaling. Taken together, our findings provide a strong rationale for testing combinations of panPI3K, PI3Kβ + IGF1R, and MAPK pathway inhibitors in PTEN(LOF)/BRAF(MUT) melanoma patients to achieve maximal response.
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http://dx.doi.org/10.1158/0008-5472.CAN-14-3358DOI Listing
January 2016

High-throughput screening using patient-derived tumor xenografts to predict clinical trial drug response.

Nat Med 2015 Nov 19;21(11):1318-25. Epub 2015 Oct 19.

Oncology Disease Area, Novartis Institutes for Biomedical Research, Emeryville, California, USA.

Profiling candidate therapeutics with limited cancer models during preclinical development hinders predictions of clinical efficacy and identifying factors that underlie heterogeneous patient responses for patient-selection strategies. We established ∼1,000 patient-derived tumor xenograft models (PDXs) with a diverse set of driver mutations. With these PDXs, we performed in vivo compound screens using a 1 × 1 × 1 experimental design (PDX clinical trial or PCT) to assess the population responses to 62 treatments across six indications. We demonstrate both the reproducibility and the clinical translatability of this approach by identifying associations between a genotype and drug response, and established mechanisms of resistance. In addition, our results suggest that PCTs may represent a more accurate approach than cell line models for assessing the clinical potential of some therapeutic modalities. We therefore propose that this experimental paradigm could potentially improve preclinical evaluation of treatment modalities and enhance our ability to predict clinical trial responses.
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http://dx.doi.org/10.1038/nm.3954DOI Listing
November 2015

Characterization of the novel and specific PI3Kα inhibitor NVP-BYL719 and development of the patient stratification strategy for clinical trials.

Mol Cancer Ther 2014 May 7;13(5):1117-29. Epub 2014 Mar 7.

Authors' Affiliations: Novartis Institutes for BioMedical Research, Disease Area Oncology; Novartis Institutes for BioMedical Research, Global Discovery Chemistry; Novartis Institutes for BioMedical Research, Center for Proteomic Chemistry; Novartis Pharma AG, Oncology Translational Medicine, Basel, Switzerland; Novartis Pharma AG, Oncology Translational Medicine; Novartis Institutes for BioMedical Research, Developmental and Molecular Pathways, Cambridge, Massachusetts; and Novartis Institutes for BioMedical Research, Developmental and Molecular Pathways, Shangai, China.

Somatic PIK3CA mutations are frequently found in solid tumors, raising the hypothesis that selective inhibition of PI3Kα may have robust efficacy in PIK3CA-mutant cancers while sparing patients the side-effects associated with broader inhibition of the class I phosphoinositide 3-kinase (PI3K) family. Here, we report the biologic properties of the 2-aminothiazole derivative NVP-BYL719, a selective inhibitor of PI3Kα and its most common oncogenic mutant forms. The compound selectivity combined with excellent drug-like properties translates to dose- and time-dependent inhibition of PI3Kα signaling in vivo, resulting in robust therapeutic efficacy and tolerability in PIK3CA-dependent tumors. Novel targeted therapeutics such as NVP-BYL719, designed to modulate aberrant functions elicited by cancer-specific genetic alterations upon which the disease depends, require well-defined patient stratification strategies in order to maximize their therapeutic impact and benefit for the patients. Here, we also describe the application of the Cancer Cell Line Encyclopedia as a preclinical platform to refine the patient stratification strategy for NVP-BYL719 and found that PIK3CA mutation was the foremost positive predictor of sensitivity while revealing additional positive and negative associations such as PIK3CA amplification and PTEN mutation, respectively. These patient selection determinants are being assayed in the ongoing NVP-BYL719 clinical trials.
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http://dx.doi.org/10.1158/1535-7163.MCT-13-0865DOI Listing
May 2014

Pan-PIM kinase inhibition provides a novel therapy for treating hematologic cancers.

Clin Cancer Res 2014 Apr 28;20(7):1834-45. Epub 2014 Jan 28.

Authors' Affiliations: Oncology Disease Area Research; Global Discovery Chemistry/Oncology and Exploratory Chemistry; MAP Group; Chemical and Pharmaceutical Profiling Group, Novartis Institutes for Biomedical Research, Emeryville, California; Developmental Molecular Pathways, Novartis Institutes for Biomedical Research, Cambridge, Massachusetts; Oncology Disease Area Research; and Center for Proteomic Chemistry, Novartis Institutes for Biomedical Research, Basel, Switzerland.

Purpose: PIM kinases have been shown to act as oncogenes in mice, with each family member being able to drive progression of hematologic cancers. Consistent with this, we found that PIMs are highly expressed in human hematologic cancers and show that each isoform has a distinct expression pattern among disease subtypes. This suggests that inhibitors of all three PIMs would be effective in treating multiple hematologic malignancies.

Experimental Design: Pan-PIM inhibitors have proven difficult to develop because PIM2 has a low Km for ATP and, thus, requires a very potent inhibitor to effectively block the kinase activity at the ATP levels in cells. We developed a potent and specific pan-PIM inhibitor, LGB321, which is active on PIM2 in the cellular context.

Results: LGB321 is active on PIM2-dependent multiple myeloma cell lines, where it inhibits proliferation, mTOR-C1 signaling and phosphorylation of BAD. Broad cancer cell line profiling of LGB321 demonstrates limited activity in cell lines derived from solid tumors. In contrast, significant activity in cell lines derived from diverse hematological lineages was observed, including acute lymphoblastic leukemia (ALL), acute myelogenous leukemia (AML), multiple myeloma and non-Hodgkin lymphoma (NHL). Furthermore, we demonstrate LGB321 activity in the KG-1 AML xenograft model, in which modulation of pharmacodynamics markers is predictive of efficacy. Finally, we demonstrate that LGB321 synergizes with cytarabine in this model.

Conclusions: We have developed a potent and selective pan-PIM inhibitor with single-agent antiproliferative activity and show that it synergizes with cytarabine in an AML xenograft model. Our results strongly support the development of Pan-PIM inhibitors to treat hematologic malignancies.
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http://dx.doi.org/10.1158/1078-0432.CCR-13-2062DOI Listing
April 2014

Pharmacological and genomic profiling identifies NF-κB-targeted treatment strategies for mantle cell lymphoma.

Nat Med 2014 Jan 22;20(1):87-92. Epub 2013 Dec 22.

1] Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, USA. [2].

Mantle cell lymphoma (MCL) is an aggressive malignancy that is characterized by poor prognosis. Large-scale pharmacological profiling across more than 100 hematological cell line models identified a subset of MCL cell lines that are highly sensitive to the B cell receptor (BCR) signaling inhibitors ibrutinib and sotrastaurin. Sensitive MCL models exhibited chronic activation of the BCR-driven classical nuclear factor-κB (NF-κB) pathway, whereas insensitive cell lines displayed activation of the alternative NF-κB pathway. Transcriptome sequencing revealed genetic lesions in alternative NF-κB pathway signaling components in ibrutinib-insensitive cell lines, and sequencing of 165 samples from patients with MCL identified recurrent mutations in TRAF2 or BIRC3 in 15% of these individuals. Although they are associated with insensitivity to ibrutinib, lesions in the alternative NF-κB pathway conferred dependence on the protein kinase NIK (also called mitogen-activated protein 3 kinase 14 or MAP3K14) both in vitro and in vivo. Thus, NIK is a new therapeutic target for MCL treatment, particularly for lymphomas that are refractory to BCR pathway inhibitors. Our findings reveal a pattern of mutually exclusive activation of the BCR-NF-κB or NIK-NF-κB pathways in MCL and provide critical insights into patient stratification strategies for NF-κB pathway-targeted agents.
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http://dx.doi.org/10.1038/nm.3435DOI Listing
January 2014

Prognostic value of PLAGL1-specific CpG site methylation in soft-tissue sarcomas.

PLoS One 2013 15;8(11):e80741. Epub 2013 Nov 15.

Institut Bergonié, Comprehensive Cancer Centre, Bordeaux, France ; Univ. Bordeaux, Bordeaux, France ; INSERM U916 VINCO, Bordeaux, France.

Soft tissue sarcomas (STS) are rare, complex tumors with a poor prognosis. The identification of new prognostic biomarkers is needed to improve patient management. Our aim was to determine the methylation status of the 118 CpG sites in the PLAGL1 tumor-suppressor gene P1 CpG island promoter and study the potential prognostic impact of PLAGL1 promoter methylation CpG sites in STS. Training cohorts constituted of 28 undifferentiated sarcomas (US) and 35 leiomyosarcomas (LMS) were studied. PLAGL1 mRNA expression was investigated by microarray analysis and validated by RT-qPCR. Pyrosequencing was used to analyze quantitative methylation of the PLAGL1 promoter. Associations between global promoter or specific CpG site methylation and mRNA expression were evaluated using Pearson's product moment correlation coefficient. Cox univariate and multivariate proportional hazard models were used to assess the predictive power of CpG site methylation status. Sixteen CpG sites associated with PLAGL1 mRNA expression were identified in US and 6 in LMS. Statistical analyses revealed an association between CpG107 methylation status and both overall and metastasis-free survival in US, which was confirmed in a validation cohort of 37 US. The exhaustive study of P1 PLAGL1 promoter methylation identified a specific CpG site methylation correlated with mRNA expression, which was predictive for both metastasis-free and overall survival and may constitute the first US-specific biomarker. Such a biomarker may be relevant for identifying patients likely to derive greater benefit from treatment.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0080741PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3829972PMC
August 2014

Fibroblast growth factor receptors as novel therapeutic targets in SNF5-deleted malignant rhabdoid tumors.

PLoS One 2013 30;8(10):e77652. Epub 2013 Oct 30.

Novartis Institutes for BioMedical Research, Basel, Switzerland.

Malignant rhabdoid tumors (MRTs) are aggressive pediatric cancers arising in brain, kidney and soft tissues, which are characterized by loss of the tumor suppressor SNF5/SMARCB1. MRTs are poorly responsive to chemotherapy and thus a high unmet clinical need exists for novel therapies for MRT patients. SNF5 is a core subunit of the SWI/SNF chromatin remodeling complex which affects gene expression by nucleosome remodeling. Here, we report that loss of SNF5 function correlates with increased expression of fibroblast growth factor receptors (FGFRs) in MRT cell lines and primary tumors and that re-expression of SNF5 in MRT cells causes a marked repression of FGFR expression. Conversely, siRNA-mediated impairment of SWI/SNF function leads to elevated levels of FGFR2 in human fibroblasts. In vivo, treatment with NVP-BGJ398, a selective FGFR inhibitor, blocks progression of a murine MRT model. Hence, we identify FGFR signaling as an aberrantly activated oncogenic pathway in MRTs and propose pharmacological inhibition of FGFRs as a potential novel clinical therapy for MRTs.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0077652PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3813701PMC
August 2014

FGFR genetic alterations predict for sensitivity to NVP-BGJ398, a selective pan-FGFR inhibitor.

Cancer Discov 2012 Dec 20;2(12):1118-33. Epub 2012 Sep 20.

Global Discovery Chemistry, 2Disease Area Oncology, Novartis Institutes for BioMedical Research, Basel, Switzerland.

Unlabelled: Patient stratification biomarkers that enable the translation of cancer genetic knowledge into clinical use are essential for the successful and rapid development of emerging targeted anticancer therapeutics. Here, we describe the identification of patient stratification biomarkers for NVP-BGJ398, a novel and selective fibroblast growth factor receptor (FGFR) inhibitor. By intersecting genome-wide gene expression and genomic alteration data with cell line-sensitivity data across an annotated collection of cancer cell lines called the Cancer Cell Line Encyclopedia, we show that genetic alterations for FGFR family members predict for sensitivity to NVP-BGJ398. For the first time, we report oncogenic FGFR1 amplification in osteosarcoma as a potential patient selection biomarker. Furthermore, we show that cancer cell lines harboring FGF19 copy number gain at the 11q13 amplicon are sensitive to NVP-BGJ398 only when concomitant expression of β-klotho occurs. Thus, our findings provide the rationale for the clinical development of FGFR inhibitors in selected patients with cancer harboring tumors with the identified predictors of sensitivity.

Significance: The success of a personalized medicine approach using targeted therapies ultimately depends on being able to identify the patients who will benefit the most from any given drug. To this end, we have integrated the molecular profiles for more than 500 cancer cell lines with sensitivity data for the novel anticancer drug NVP-BGJ398 and showed that FGFR genetic alterations are the most significant predictors for sensitivity. This work has ultimately endorsed the incorporation of specific patient selection biomakers in the clinical trials for NVP-BGJ398.
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http://dx.doi.org/10.1158/2159-8290.CD-12-0210DOI Listing
December 2012

Gene expression signature predicting high-grade prostate cancer responses to oxaliplatin.

Mol Pharmacol 2012 Dec 17;82(6):1205-16. Epub 2012 Sep 17.

NSERM U916, Institut Bergonié and Université de Bordeaux, France

Prostate cancer is one of the leading causes of cancer-related deaths among men. Several prognostic factors allow differentiation of low-grade tumors from high-grade tumors with high metastatic potential. High-grade tumors are currently treated with hormone therapy, to which taxanes are added when the tumors become resistant to castration. Clinical trials with other anticancer agents did not take into account the genetic backgrounds of the tumors, and most trials demonstrated low response rates. Here we used an in silico approach to screen for drug candidates that might be used as alternatives to taxanes, on the basis of a published expression signature involving 86 genes that could distinguish high-grade and low-grade tumors (Proc Natl Acad Sci USA 103:10991-10996, 2006). We explored the National Cancer Institute databases, which include data on the gene expression profiles of 60 human tumor cell lines and the in vitro sensitivities of the cell lines to anticancer drugs, and we identified several genes in the signature for which expression levels were correlated with chemosensitivity. As an example of the validation of this in silico approach, we identified a set of six genes for which expression levels could predict cell sensitivity to oxaliplatin but not cisplatin. This signature was validated in vitro through silencing of the genes in DU145, LNCaP, and C4-2B prostate cancer cells, which was accompanied by changes in oxaliplatin but not cisplatin cytotoxicity. These results demonstrate the relevance of our approach for the identification of both alternative treatments for high-grade prostate cancers and new biomarkers to predict clinical tumor responses.
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http://dx.doi.org/10.1124/mol.112.080333DOI Listing
December 2012

Characterization of the mechanism of action of the pan class I PI3K inhibitor NVP-BKM120 across a broad range of concentrations.

Mol Cancer Ther 2012 Aug 31;11(8):1747-57. Epub 2012 May 31.

NIBR Oncology Disease Area, Novartis Pharma AG, Basel CH4002, Switzerland.

The pan-phosphoinositide 3-kinase (PI3K) inhibitor BKM120 was found, at high concentrations, to cause cell death in various cellular systems, irrespective of their level of PI3K addiction. Transcriptional and biochemical profiling studies were used to identify the origin of these unexpected and apparently PI3K-independent effects. At 5- to 10-fold, the concentration needed to half-maximally inhibit PI3K signaling. BKM120 treatment caused changes in expression of mitotic genes and the induction of a robust G(2)-M arrest. Tubulin polymerization assays and nuclear magnetic resonance-binding studies revealed that BKM120 inhibited microtubule dynamics upon direct binding to tubulin. To assess the contribution of this off-target activity vis-à-vis the antitumor activity of BKM120 in PI3K-dependent tumors, we used a mechanistic PI3K-α-dependent model. We observed that, in vivo, daily treatment of mice with doses of BKM120 up to 40 mg/kg led to tumor regressions with no increase in the mitotic index. Thus, strong antitumor activity can be achieved in PI3K-dependent models at exposures that are below those necessary to engage the off-target activity. In comparison, the clinical data indicate that it is unlikely that BKM120 will achieve exposures sufficient to significantly engage the off-target activity at tolerated doses and schedules. However, in preclinical settings, the consequences of the off-target activity start to manifest themselves at concentrations above 1 μmol/L in vitro and doses above 50 mg/kg in efficacy studies using subcutaneous tumor-bearing mice. Hence, careful concentration and dose range selection is required to ensure that any observation can be correctly attributed to BKM120 inhibition of PI3K.
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http://dx.doi.org/10.1158/1535-7163.MCT-11-1021DOI Listing
August 2012

Absence of transcriptomic signature of response to chemotherapy in metastatic colorectal carcinoma patients.

Pharmacogenomics 2012 Mar 13;13(4):497-504. Epub 2012 Feb 13.

Institut Bergonié, 229 cours de l'Argonne, 33076 Bordeaux, France.

Aim: Tumor gene-expression profiling may define signatures capable of discriminating between responders and nonresponders to chemotherapy.

Patients & Methods: Fifty seven metastatic colorectal cancer patients were prospectively included and 40 tumors were analyzed. Patients were treated in first line with 5-fluorouracil associated with irinotecan or oxaliplatin. Response was evaluated using WHO criteria every 2 months after chemotherapy. Gene-expression profiling was performed using Applied Biosystems microarrays (Human Genome Survey Microarray v2.0; Paris, France). Data were analyzed using Bioconductor packages. Differential-expression analysis was performed by fitting a linear model. Moderated t-statistics were computed and p-values were adjusted for false-discovery rate. Pearson correlations tests were evaluated between gene expression and progression-free and overall survival.

Results: Nonsupervised analysis did not show any clustering of expression levels according to treatment response. Supervised analysis compared expression levels between responders and nonresponders, within each treatment group and independently from treatment. No genes were identified as differentially expressed at a p-value of 10(-3) and false-discovery rate of 30%. No correlation between expression levels and survival data was found.

Conclusion: These negative results show that the determinants of response to chemotherapy should be sought not only in the tumor characteristics, but also among the processes leading to drug availability to the tumor.
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http://dx.doi.org/10.2217/pgs.11.174DOI Listing
March 2012

Mitotic checkpoints and chromosome instability are strong predictors of clinical outcome in gastrointestinal stromal tumors.

Clin Cancer Res 2012 Feb 13;18(3):826-38. Epub 2011 Dec 13.

INSERM U916: Genetics and Biology of Sarcomas, Paris Cedex, France.

Purpose: The importance of KIT and PDGFRA mutations in the oncogenesis of gastrointestinal stromal tumors (GIST) is well established, but the genetic basis of GIST metastasis is poorly understood. We recently published a 67 gene expression prognostic signature related to genome complexity (CINSARC for Complexity INdex in SARComas) and asked whether it could predict outcome in GISTs.

Experimental Design: We carried out genome and expression profiling on 67 primary untreated GISTs.

Results: We show and validate here that it can predict metastasis in a new data set of 67 primary untreated GISTs. The gene whose expression was most strongly associated with metastasis was AURKA, but the AURKA locus was not amplified. Instead, we identified deletion of the p16 (CDKN2A) and retinoblastoma (RB1) genes as likely causal events leading to increased AURKA and CINSARC gene expression, to chromosome rearrangement, and ultimately to metastasis. On the basis of these findings, we established a Genomic Index that integrates the number and type of DNA copy number alterations. This index is a strong prognostic factor in GISTs. We show that CINSARC class, AURKA expression, and Genomic Index all outperform the Armed Forces Institute of Pathology (AFIP) grading system in determining the prognosis of patients with GISTs. Interestingly, these signatures can identify poor prognosis patients in the group classified as intermediate-risk by the AFIP classification.

Conclusions: We propose that a high Genomic Index determined by comparative genomic hybridization from formalin-fixed, paraffin-embedded samples could be used to identify AFIP intermediate-risk patients who would benefit from imatinib therapy.
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http://dx.doi.org/10.1158/1078-0432.CCR-11-1610DOI Listing
February 2012

Contributions of the EMERALD project to assessing and improving microarray data quality.

Biotechniques 2011 Jan;50(1):27-31

Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.

While minimum information about a microarray experiment (MIAME) standards have helped to increase the value of the microarray data deposited into public databases like ArrayExpress and Gene Expression Omnibus (GEO), limited means have been available to assess the quality of this data or to identify the procedures used to normalize and transform raw data. The EMERALD FP6 Coordination Action was designed to deliver approaches to assess and enhance the overall quality of microarray data and to disseminate these approaches to the microarray community through an extensive series of workshops, tutorials, and symposia. Tools were developed for assessing data quality and used to demonstrate how the removal of poor-quality data could improve the power of statistical analyses and facilitate analysis of multiple joint microarray data sets. These quality metrics tools have been disseminated through publications and through the software package arrayQualityMetrics. Within the framework provided by the Ontology of Biomedical Investigations, ontology was developed to describe data transformations, and software ontology was developed for gene expression analysis software. In addition, the consortium has advocated for the development and use of external reference standards in microarray hybridizations and created the Molecular Methods (MolMeth) database, which provides a central source for methods and protocols focusing on microarray-based technologies.
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http://dx.doi.org/10.2144/000113591DOI Listing
January 2011

Validated prediction of clinical outcome in sarcomas and multiple types of cancer on the basis of a gene expression signature related to genome complexity.

Nat Med 2010 Jul 27;16(7):781-7. Epub 2010 Jun 27.

Département de Pathologie, Institut Bergonié, Bordeaux, France.

Sarcomas are heterogeneous and aggressive mesenchymal tumors. Histological grading has so far been the best predictor for metastasis-free survival, but it has several limitations, such as moderate reproducibility and poor prognostic value for some histological types. To improve patient grading, we performed genomic and expression profiling in a training set of 183 sarcomas and established a prognostic gene expression signature, complexity index in sarcomas (CINSARC), composed of 67 genes related to mitosis and chromosome management. In a multivariate analysis, CINSARC predicts metastasis outcome in the training set and in an independent 127 sarcomas validation set. It is superior to the Fédération Francaise des Centres de Lutte Contre le Cancer grading system in determining metastatic outcome for sarcoma patients. Furthermore, it also predicts outcome for gastrointestinal stromal tumors (GISTs), breast carcinomas and lymphomas. Application of the signature will permit more selective use of adjuvant therapies for people with sarcomas, leading to decreased iatrogenic morbidity and improved outcomes for such individuals.
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http://dx.doi.org/10.1038/nm.2174DOI Listing
July 2010

Microarray data quality control improves the detection of differentially expressed genes.

Genomics 2010 Mar 14;95(3):138-42. Epub 2010 Jan 14.

EMBL-European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, UK.

Microarrays have become a routine tool for biomedical research. Data quality assessment is an essential part of the analysis, but it is still not easy to perform objectively or in an automated manner, and as a result it is often neglected. Here, we compared two strategies of array-level quality control using five publicly available microarray experiments: outlier removal and array weights. We also compared them against no outlier removal and random array removal. We find that removing outlier arrays can improve the signal-to-noise ratio and thus strengthen the power of detecting differentially expressed genes. Using array weights is similarly effective, but its applicability is more limited. The quality metrics presented here are implemented in the Bioconductor package arrayQualityMetrics.
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http://dx.doi.org/10.1016/j.ygeno.2010.01.003DOI Listing
March 2010

Importing ArrayExpress datasets into R/Bioconductor.

Bioinformatics 2009 Aug 8;25(16):2092-4. Epub 2009 Jun 8.

EMBL-EBI, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK.

Summary: ArrayExpress is one of the largest public repositories of microarray datasets. R/Bioconductor provides a comprehensive suite of microarray analysis and integrative bioinformatics software. However, easy ways for importing datasets from ArrayExpress into R/Bioconductor have been lacking. Here, we present such a tool that is suitable for both interactive and automated use.

Availability: The ArrayExpress package is available from the Bioconductor project at http://www.bioconductor.org. A users guide and examples are provided with the package.
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http://dx.doi.org/10.1093/bioinformatics/btp354DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2723004PMC
August 2009

MYCN-non-amplified metastatic neuroblastoma with good prognosis and spontaneous regression: a molecular portrait of stage 4S.

Mol Oncol 2008 Oct 23;2(3):261-71. Epub 2008 Jul 23.

Molecular Interactions in Cancer CNRS-UMR 8126, IFR54, Institut Gustave Roussy, 39, rue C. Desmoulins, Villejuif 94805 Cedex, France.

Stage 4 neuroblastoma (NB) are heterogeneous regarding their clinical presentations and behavior. Indeed infants (stage 4S and non-stage 4S of age <365days at diagnosis) show regression contrasting with progression in children (>365days). Our study aimed at: (i) identifying age-based genomic and gene expression profiles of stage 4 NB supporting this clinical stratification; and (ii) finding a stage 4S NB signature. Differential genome and transcriptome analyses of a learning set of MYCN-non amplified stage 4 NB tumors at diagnosis (n=29 tumors including 12 stage 4S) were performed using 1Mb BAC microarrays and Agilent 22K probes oligo-microarrays. mRNA chips data following filtering yielded informative genes before supervised hierarchical clustering to identify relationship among tumor samples. After confirmation by quantitative RT-PCR, a stage 4S NB's gene cluster was obtained and submitted to a validation set (n=22 tumors). Genomic abnormalities of infant's tumors (whole chromosomes gains or loss) differ radically from that of children (intra-chromosomal rearrangements) but could not discriminate infants with 4S from those without this presentation. In contrast, differential gene expression by looking at both individual genes and whole biological pathways leads to a molecular stage 4S NB portrait which provides new biological clues about this fascinating entity.
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http://dx.doi.org/10.1016/j.molonc.2008.07.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5527812PMC
October 2008

Candidate genes on chromosome 9q33-34 involved in the progression of childhood ependymomas.

J Clin Oncol 2009 Apr 16;27(11):1884-92. Epub 2009 Mar 16.

Department of Neurosurgery, Peter B Dirks, Christian Sainte-Rose, and Gilles Vassal Hôpital Necker Enfants Malades, Université Paris Descartes, France.

Purpose: The molecular pathogenesis of pediatric ependymoma remains unclear. Our study was designed to identify genetic changes implicated in ependymoma progression.

Patients And Methods: We characterized 59 ependymoma samples (33 at diagnosis and 26 at relapse) using array-comparative genomic hybridization (aCGH). Specific chromosomal imbalances were confirmed by fluorescent in situ hybridization, and candidate genes were assessed by real-time quantitative polymerase chain reaction (qPCR), immunohistochemistry, sequencing, and in vitro functional studies.

Results: aCGH analysis revealed a significant increase in genomic imbalances on relapse compared with diagnosis, such as gain of 9qter and 1q (54% v 21% and 12% v 0%, respectively) and loss of 6q (27% v 6%). Supervised tumor classification showed that gain of 9qter was associated with tumor recurrence, age older than 3 years, and posterior fossa location. Using a candidate-gene strategy, we found an overexpression of two potential oncogenes at the locus 9qter: Tenascin-C and Notch1. Moreover, Notch pathway analysis (qPCR) revealed overexpression of Notch ligands, receptors, and target genes (Hes-1, Hey2, and c-Myc), and downregulation of Notch repressor Fbxw7. We confirmed by immunohistochemistry the overexpression of Tenascin-C and Hes-1. We detected Notch1 missense mutations in 8.3% of the tumors (only in the posterior fossa location and in case of 9q33-34 gain). Furthermore, inhibition of Notch pathway with a gamma-secretase inhibitor impaired the growth of ependymoma stem cell cultures.

Conclusion: The activation of the Notch pathway and Tenascin-C seem to be important events in ependymoma progression and may represent future targets for therapy. We report, to our knowledge for the first time, recurrent oncogenic mutations in pediatric posterior fossa ependymomas.
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http://dx.doi.org/10.1200/JCO.2007.15.4195DOI Listing
April 2009

arrayQualityMetrics--a bioconductor package for quality assessment of microarray data.

Bioinformatics 2009 Feb 23;25(3):415-6. Epub 2008 Dec 23.

EMBL European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK.

Summary: The assessment of data quality is a major concern in microarray analysis. arrayQualityMetrics is a Bioconductor package that provides a report with diagnostic plots for one or two colour microarray data. The quality metrics assess reproducibility, identify apparent outlier arrays and compute measures of signal-to-noise ratio. The tool handles most current microarray technologies and is amenable to use in automated analysis pipelines or for automatic report generation, as well as for use by individuals. The diagnosis of quality remains, in principle, a context-dependent judgement, but our tool provides powerful, automated, objective and comprehensive instruments on which to base a decision.

Availability: arrayQualityMetrics is a free and open source package, under LGPL license, available from the Bioconductor project at www.bioconductor.org. A users guide and examples are provided with the package. Some examples of HTML reports generated by arrayQualityMetrics can be found at http://www.microarray-quality.org
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http://dx.doi.org/10.1093/bioinformatics/btn647DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2639074PMC
February 2009