Richard Iggo

University of Bordeaux, Burdeos, Aquitaine, France

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Publications (101)813.33 Total impact

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    ABSTRACT: Understanding the cell of origin of cancer is pivotal for a better prevention and more efficient cure of the disease. Some examples of cancers arising from the transformation of stem cells have been shown, but in most cases, the cell of origin remains unknown. In healthy tissue, the microenvironment (niche) governs the fate of stem cells by balancing their self-renewal and differentiation through the regulation of the availability of soluble molecules, cell-cell contact, cell-matrix interactions, and physical constraints (Maguer-Satta, 2011). Increasing evidence indicates that the microenvironment plays an active role in cancer, such as alterations of mesenchymal stem cells that promote the proliferation and dissemination of cancer cells (McLean et al., 2011). However, the role of the microenvironment in the initial steps of cell transformation remains unexplored.
    Stem Cell Reports 01/2015; 26(2). DOI:10.1016/j.stemcr.2014.12.007
  • Richard Iggo, Elodie Richard
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    ABSTRACT: Lentiviral vectors are the workhorses of modern cell biology. They can infect a wide variety of cells including nondividing cells and stem cells. They integrate into the genome of infected cells leading to stable expression. It is easy to transduce 100 % of the cells in a culture and possible to infect cells simultaneously with multiple vectors, greatly facilitating studies on malignant transformation. We present simple protocols to produce and titrate lentiviral vectors, infect mammary epithelial cells, and check for contamination with replication-competent viruses.
    Methods in molecular biology (Clifton, N.J.) 01/2015; 1293:137-60. DOI:10.1007/978-1-4939-2519-3_8 · 1.29 Impact Factor
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    ABSTRACT: IntroductionThe cell of origin for estrogen receptor ¿ (ER¿) positive breast cancer is probably a luminal stem cell in the terminal duct lobular units. To model these cells we have used the murine myoepithelial layer in the mouse mammary ducts as a scaffold upon which to build a human luminal layer. To prevent squamous metaplasia, a common artifact in genetically engineered breast cancer models, we sought to limit activation of the epidermal growth factor receptor (EGFR) during in vitro cell culture before grafting the cells.Methods Human reduction mammoplasty cells were grown in vitro in WIT medium. Epidermal growth factor (EGF) in the medium was replaced with amphiregulin and neuregulin to decrease activation of EGFR and increase activation of EGFR homologs 3 and 4 (ERBB3 and ERBB4). Lentiviral vectors were used to express oncogenic transgenes and fluorescent proteins. Human mammary epithelial cells were mixed with irradiated mouse fibroblasts and matrigel, then injected through the nipple into the mammary ducts of immunodeficient mice. Engrafted cells were visualized by stereomicroscopy for fluorescent proteins and characterized by histology and immunohistochemistry.ResultsGrowth of normal mammary epithelial cells in conditions favoring ERBB3/4 signaling prevented squamous metaplasia in vitro. Normal human cells were quickly lost after intraductal injection but cells infected with lentiviruses expressing CCND1, MYC, TERT, BMI1 and a short hairpin RNA targeting TP53 were able to engraft and progressively replace the luminal layer in the mouse mammary ducts, resulting in the formation of an extensive network of humanized ducts. Despite expressing multiple oncogenes, the human cells formed a morphologically normal luminal layer. Expression of a single additional oncogene, PIK3CA-H1047R, converted the cells into invasive cancer cells. The resulting tumors were ER¿+, Ki67+ luminal B adenocarcinomas that were resistant to treatment with fulvestrant.Conclusions Injection of preneoplastic human mammary epithelial cells into the mammary ducts of immunodeficient mice leads to replacement of the murine luminal layer with morphologically normal human cells. Genetic manipulation of the injected cells makes it possible to study defined steps in the transformation of human mammary epithelial cells in a more physiological environment than has hitherto been possible.
    Breast cancer research: BCR 12/2014; 16(6):504. DOI:10.1186/s13058-014-0504-9 · 5.88 Impact Factor
  • Cancer Research 03/2014; 73(24 Supplement):P1-15-01-P1-15-01. DOI:10.1158/0008-5472.SABCS13-P1-15-01 · 9.28 Impact Factor
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    ABSTRACT: We have previously tested biopsies from 1469 breast tumours with a p53 functional assay in the context of a prospective clinical trial (EORTC 10994/BIG 1-00). The goal of the trial was to determine whether p53 status could be used to select patients who would benefit from inclusion of taxanes in anthracycline-based chemotherapy. The results of the trial were negative. To test whether this was because the functional assay misclassified the tumours we have reanalysed two groups of biopsies by Sanger sequencing and Roche 454 next generation sequencing (NGS). Comparison of yeast data with pooled cDNA sequencing data in an initial cohort of 69 biopsies showed that conventional sequencing is insensitive when the mutant p53 content is low. A second cohort of 48 biopsies was used to compare directly the yeast assay with Sanger and NGS technology. The mutant sequence was difficult to detect in sequence chromatograms of pooled cDNA whereas NGS unequivocally identified mutations in every case classified as mutant by the functional assay. The NGS data showed that small deletions, probably caused by PCR splicing, account for most of the unexplained background in the yeast assay. We conclude that mutation detection techniques that test multiple clones, such as the p53 functional assay and NGS, are more reliable than Sanger sequencing of pooled DNA; that the high p53 mutation rate (44%) seen with the yeast assay in the EORTC 10994/BIG 1-00 trial reflects this high sensitivity; and that NGS with Roche 454 technology could be used to identify the p53 mutations in the remaining tumours previously tested in yeast in the EORTC10994/BIG 1-00 trial.
    The Journal of Pathology 12/2013; 231(4). DOI:10.1002/path.4243 · 7.33 Impact Factor
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    Ji-Hyun Lim, Richard D Iggo, Daniel Barker
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    ABSTRACT: Genome-wide prediction of transcription factor binding sites is notoriously difficult. We have developed and applied a logistic regression approach for prediction of binding sites for the p53 transcription factor that incorporates sequence information and chromatin modification data. We tested this by comparison of predicted sites with known binding sites defined by chromatin immunoprecipitation (ChIP), by the location of predictions relative to genes, by the function of nearby genes and by analysis of gene expression data after p53 activation. We compared the predictions made by our novel model with predictions based only on matches to a sequence position weight matrix (PWM). In whole genome assays, the fraction of known sites identified by the two models was similar, suggesting that there was little to be gained from including chromatin modification data. In contrast, there were highly significant and biologically relevant differences between the two models in the location of the predicted binding sites relative to genes, in the function of nearby genes and in the responsiveness of nearby genes to p53 activation. We propose that these contradictory results can be explained by PWM and ChIP data reflecting primarily biophysical properties of protein-DNA interactions, whereas chromatin modification data capture biologically important functional information.
    Nucleic Acids Research 04/2013; 41(11). DOI:10.1093/nar/gkt260 · 9.11 Impact Factor
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    ABSTRACT: Germline BRCA1 or BRCA2 mutations account for 20-30% of familial clustering of breast cancer. The main indication for BRCA2 screening is currently the family history but the yield of mutations identified in patients selected this way is low. To develop more efficient approaches to screening we have compared the gene expression and genomic profiles of BRCA2-mutant breast tumors with those of breast tumors lacking BRCA1 or BRCA2 mutations. We identified a group of 66 genes showing differential expression in our training set of 7 BRCA2-mutant tumors and in an independent validation set of 19 BRCA2-mutant tumors. The differentially expressed genes include a prominent cluster of genes from chromosomes 13 and 14 whose expression is reduced. Gene set enrichment analysis confirmed that genes in specific bands on 13q and 14q showed significantly reduced expression, suggesting that the affected bands may be preferentially deleted in BRCA2-mutant tumors. Genomic profiling showed that the BRCA2-mutant tumors indeed harbor deletions on chromosomes 13q and 14q. To exploit this information we have created a simple fluorescence in situ hybridization (FISH) test and shown that it detects tumors with deletions on chromosomes 13q and 14q. Together with previous reports, this establishes that deletions on chromosomes 13q and 14q are a hallmark of BRCA2-mutant tumors. We propose that FISH to detect these deletions would be an efficient and cost-effective first screening step to identify potential BRCA2-mutation carriers among breast cancer patients without a family history of breast cancer.
    PLoS ONE 12/2012; 7(12):e52079. DOI:10.1371/journal.pone.0052079 · 3.53 Impact Factor
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    Richard D Iggo
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    ABSTRACT: Two recent studies on a rare androgen-dependent form of breast cancer have shed light on the biology of luminal tumours and reinforced the view that interfering with androgen signalling may have a place in the therapy of some forms of breast cancer.
    Breast cancer research: BCR 12/2011; 13(6):318. DOI:10.1186/bcr3036 · 5.88 Impact Factor
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    ABSTRACT: TP53 has a crucial role in the DNA damage response. We therefore tested the hypothesis that taxanes confer a greater advantage than do anthracyclines on breast cancers with mutated TP53 than in those with wild-type TP53. In an open-label, phase 3 study, women (age <71 years) with locally advanced, inflammatory, or large operable breast cancers were randomly assigned in a 1:1 ratio to either a standard anthracycline regimen (six cycles of intravenous fluorouracil 500 mg/m², epirubicin 100 mg/m², and cyclophosphamide 500 mg/m² every 21 days [FEC100], or fluorouracil 600 mg/m², epirubicin 75 mg/m², cyclophosphamide 900 mg/m² [tailored FEC] starting on day 1 and then every 21 days) or a taxane-based regimen (three cycles of docetaxel 100 mg/m², intravenously infused over 1 h on day 1 every 21 days, followed by three cycles of intravenous epirubicin 90 mg/m² and docetaxel 75 mg/m² on day 1 every 21 days [T-ET]) at 42 centres in Europe. Randomisation was by use of a minimisation method that stratified patients by institution and initial tumour stage. The primary endpoint was progression-free survival (PFS) according to TP53 status. Analysis was by intention to treat. This is the final analysis of this trial. The study is registered with ClinicalTrials.gov, number NCT00017095. 928 patients were enrolled in the FEC group and 928 in the T-ET group. TP53 status was not assessable for 183 (20%) patients in the FEC group and 204 (22%) patients in the T-ET group mainly because of low tumour-cell content in the biopsy. 361 primary endpoint events were recorded in the FEC group and 314 in the T-ET group. In patients with TP53-mutated tumours, 5-year PFS was 59·5% (95% CI 53·4-65·1) in the T-ET group (n=326) and 55·3% (49·2-60·9) in the FEC group (n=318; hazard ratio 0·84, 98% CI 0·63-1·14; p=0·17). In patients with TP53 wild-type tumours, 5-year PFS was 66·8% (95% CI 61·4-71·6) in the T-ET group (n=398) and 64·7% (59·6-69·4) in the FEC group (n=427; 0·89, 98% CI 0·68-1·18; p=0·35). For all patients, irrespective of TP53 status, 5-year PFS was 65·1% (95% CI 61·6-68·3) in the T-ET group and 60·8% (57·3-64·2) in the FEC group (0·85, 98% CI 0·71-1·02; p=0·035). At the sites using FEC100 versus T-ET, the most common grade 3 or 4 adverse events were febrile neutropenia (75 [9%] of 803 vs 173 [21%] of 809, respectively), and neutropenia (653 [81%] vs 730 [90%], respectively). At the sites using tailored FEC versus T-ET, the most common grade 3 or 4 adverse events were febrile neutropenia (ten [8%] of 118 vs 26 [22%] of 116, respectively), and neutropenia (100 [85%] vs 115 [99%], respectively). Two patients died of toxicity during or within 30 days of chemotherapy completion and without disease relapse (one in each group). Although TP53 status was prognostic for overall survival, it was not predictive of preferential sensitivity to taxanes. TP53 status tested by use of the yeast assay in this patient population cannot be used to select patients for an anthracycline-based chemotherapy versus a taxane-based chemotherapy. US National Cancer Institute, La Ligue Nationale Contre le Cancer, European Union, Pharmacia, and Sanofi-Aventis.
    The Lancet Oncology 06/2011; 12(6):527-39. DOI:10.1016/S1470-2045(11)70094-8 · 24.73 Impact Factor
  • The Lancet Oncology 02/2011; 12(2):116. DOI:10.1016/S1470-2045(11)70011-0 · 24.73 Impact Factor
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    ABSTRACT: Breast carcinoma is the main malignant tumor occurring in patients with Cowden disease, a cancer-prone syndrome caused by germline mutation of the tumor suppressor gene PTEN characterized by the occurrence throughout life of hyperplastic, hamartomatous and malignant growths affecting various organs. The absence of known histological features for breast cancer arising in a PTEN-mutant background prompted us to explore them for potential new markers. We first performed a microarray study of three tumors from patients with Cowden disease in the context of a transcriptomic study of 74 familial breast cancers. A subsequent histological and immunohistochemical study including 12 additional cases of Cowden disease breast carcinomas was performed to confirm the microarray data. Unsupervised clustering of the 74 familial tumors followed the intrinsic gene classification of breast cancer except for a group of five tumors that included the three Cowden tumors. The gene expression profile of the Cowden tumors shows considerable overlap with that of a breast cancer subgroup known as molecular apocrine breast carcinoma, which is suspected to have increased androgenic signaling and shows frequent ERBB2 amplification in sporadic tumors. The histological and immunohistochemical study showed that several cases had apocrine histological features and expressed GGT1, which is a potential new marker for apocrine breast carcinoma. These data suggest that activation of the ERBB2-PI3K-AKT pathway by loss of PTEN at early stages of tumorigenesis promotes the formation of breast tumors with apocrine features.
    Breast cancer research: BCR 08/2010; 12(4):R63. DOI:10.1186/bcr2626 · 5.88 Impact Factor
  • EJC Supplements 03/2010; 8(3):124. DOI:10.1016/S1359-6349(10)70250-0 · 9.39 Impact Factor
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    ABSTRACT: The Na/I symporter (hNIS) promotes concentration of iodine in cells. In cancer gene therapy, this transgene has potential as a reporter gene for molecular imaging of viral biodistribution and as a therapeutic protein promoting (131)I-mediated radiotherapy. Here, we combined the imaging and therapeutic potential of hNIS in an oncolytic adenoviruses targeting colorectal cancer cells. We generated an adenovirus (AdIP2) encoding hNIS and capable of selective replication in colorectal carcinoma cells. The selectivity of this virus was verified in vitro and in vivo. Its spread in tumors was monitored in vivo using single-photon emission computed tomography/CT imaging upon (99m)TcO(4)(-) injection and confirmed by immunohistochemistry. Metabolic radiotherapy was done through injection of therapeutic doses of (131)I(-). We showed in vitro and in vivo the selectivity of AdIP2 and that hNIS expression is restricted to the target cells. Imaging and immunohistochemical data showed that viral spread is limited and that the point of maximal hNIS expression is reached 48 hours after a single intratumoral injection. Administration of a single therapeutic dose of (131)I at this time point led to a dramatic reduction in tumor size not observed in hNIS-negative viruses. This report showed for the first time that the combination of the imaging and therapeutic potentials of hNIS can be applied to oncolytic adenoviruses in experimental models of cancer.
    Clinical Cancer Research 11/2009; 15(21):6595-601. DOI:10.1158/1078-0432.CCR-09-0262 · 8.19 Impact Factor
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    ABSTRACT: Markers that predict the sensitivity of tumours to chemotherapy must address two questions: (a) which tumours are more likely to respond to chemotherapy? and (b) what is the optimal chemotherapy regimen for a specific tumour or group of tumours? To answer these questions will require markers of general chemosensitivity and drug-specific chemosensitivity, respectively. Beyond these fundamental questions lies an important practical question: are the predictive markers in the current literature ready for routine clinical use? The focus of this paper is to address this practical question. We will first review retrospective trials that have reported promising chemotherapy signatures, presenting in a comprehensive manner for the non bio-informatician the different methods used so far. In addition, we will summarise prospective trials (either ongoing or under development) designed to test the multigene classifiers currently thought to predict chemosensitivity. Finally, we will discuss why microarray studies have so far failed to identify new targets, and how we might be able to improve on these results through large-scale genotyping of tumours.
    European journal of cancer (Oxford, England: 1990) 08/2009; 45(10):1733-43. DOI:10.1016/j.ejca.2009.04.036 · 4.82 Impact Factor
  • Cancer Research 02/2009; 69(2 Supplement):1067-0. DOI:10.1158/0008-5472.SABCS-1067 · 9.28 Impact Factor
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    ABSTRACT: To better understand the relationship between tumor-host interactions and the efficacy of chemotherapy, we have developed an analytical approach to quantify several biological processes observed in gene expression data sets. We tested the approach on tumor biopsies from individuals with estrogen receptor-negative breast cancer treated with chemotherapy. We report that increased stromal gene expression predicts resistance to preoperative chemotherapy with 5-fluorouracil, epirubicin and cyclophosphamide (FEC) in subjects in the EORTC 10994/BIG 00-01 trial. The predictive value of the stromal signature was successfully validated in two independent cohorts of subjects who received chemotherapy but not in an untreated control group, indicating that the signature is predictive rather than prognostic. The genes in the signature are expressed in reactive stroma, according to reanalysis of data from microdissected breast tumor samples. These findings identify a previously undescribed resistance mechanism to FEC treatment and suggest that antistromal agents may offer new ways to overcome resistance to chemotherapy.
    Nature medicine 02/2009; 15(1):68-74. DOI:10.1038/nm.1908 · 28.05 Impact Factor
  • Nature Medicine 02/2009; DOI:10.1038/nm0209-220a · 28.05 Impact Factor
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    ABSTRACT: Constitutive activation of the Wnt signaling pathway is a hallmark of many cancers and has been associated with familial and sporadic desmoid tumors. The aim of the present study is to assess the therapeutic potential of oncolytic adenoviruses selectively replicating in cells in which the Wnt signaling pathway is active on primary cells from desmoid tumors. Primary cells extracted from familial (n = 3) or sporadic (n = 3) desmoid tumors were cultured short term. Cancer cell survival and viral replication were measured in vitro upon infection with two different oncolytic adenoviruses targeting a constitutive activation of the Wnt signaling pathway. Adenoviral infectivity was also assessed. Although cells extracted from one sporadic desmoid tumor responded very well to the oncolytic action of the adenoviruses (<20% of viable cells upon infection at a multiplicity of infection of 10), cells from two tumor samples were totally resistant to the viral action. Cells from the remaining samples showed intermediate sensitivity to the oncolytic viruses. These effects were correlated to the level of infectivity of the cells. Finally, in responder cells, evidences of viral replication was observed. Our experimental data suggest that the response of desmoid tumor cells to oncolytic adenovirus is neither correlated to the type of mutation activating the Wnt signaling pathway nor to the familial or sporadic nature of the tumor. In addition, they highlight the variability of infectivity of individual tumors and predict a great variability in the response to oncolytic adenoviruses.
    Clinical Cancer Research 11/2008; 14(19):6187-92. DOI:10.1158/1078-0432.CCR-08-0410 · 8.19 Impact Factor
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    ABSTRACT: Oncolytic viruses are regulated by the tumor phenotype to replicate and lyse cancer cells selectively. To identify optimal strategies for breast cancer we compared five adenoviruses with distinct regulatory mechanisms: Ad-dl922-947 (targets G1-S checkpoint); Ad-Onyx-015 and Ad-Onyx-017 (target p53/mRNA export); Ad-vKH1 (targets Wnt pathway), and AdEHE2F (targets estrogen receptor/G1-S checkpoint/hypoxic signaling). The quantity of virus required to kill 50% of breast cancer cells after 6 days (EC(50), plaque-forming units per cell) was measured. The most potent virus was Ad-dl922-947 (EC(50), 0.01-5.4 in SkBr3, MDA-231, MDA-468, MCF7, and ZR75.1 cells), followed by wild-type (Ad-WT; EC(50), 0.3-5.5) and AdEHE2F (EC(50), 1.4-3.9). Ad-vKH1 (EC(50), 7.2-72.1), Ad-Onyx-017 (EC(50), 8.4-167), and Ad-Onyx-015 (EC(50), 17.7-377) showed less activity. Most viruses showed limited cytotoxicity in normal human cells, including breast epithelium MCF10A (EC(50), >722) and fibroblasts (EC(50), >192) and only moderate cytotoxicity in normal microvascular endothelial cells (HMVECs; EC(50), 42.8-149), except Ad-dl922-947, which was active in HMVECs (EC(50), 1.6). After injection into MDA-231 xenografts, Ad-WT, AdEHE2F, and Ad-dl922-947 showed replication, assessed by hexon staining and quantitative polymerase chain reaction measurement of viral DNA, and significantly inhibited tumor growth, leading to extended survival. After intravenous injection Ad-dl922-947 showed DNA replication (233% of the injected dose was measured in liver after 3 days) whereas AdEHE2F did not. Overall, AdEHE2F showed the best combination of low toxicity in normal cells and high activity in breast cancer in vitro and in vivo, suggesting that molecular targeting using estrogen response elements, hypoxia response elements, and a dysregulated G1-S checkpoint is a promising strategy for virotherapy of breast cancer.
    Human gene therapy 08/2008; 19(9):873-86. DOI:10.1089/hum.2008.047 · 3.62 Impact Factor

Publication Stats

7k Citations
813.33 Total Impact Points

Institutions

  • 2009–2015
    • University of Bordeaux
      Burdeos, Aquitaine, France
  • 2006–2014
    • University of St Andrews
      • School of Medicine
      Saint Andrews, Scotland, United Kingdom
  • 2011
    • Institut Bergonié
      Burdeos, Aquitaine, France
  • 1999
    • Hôpitaux Universitaires de Genève
      Genève, Geneva, Switzerland
  • 1997
    • University Hospital of Lausanne
      Lausanne, Vaud, Switzerland
    • Schweizerischen Arbeitsgemeinschaft für Klinische Krebsforschung
      Berna, Bern, Switzerland
    • Hokkaido University Hospital
      • Division of Neurosurgery
      Sapporo, Hokkaidō, Japan
  • 1991
    • Institute for Clinical and Experimental Medicine (IKEM)
      Praha, Praha, Czech Republic