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3.
Leukemia ; 32(2): 332-342, 2018 02.
Article in English | MEDLINE | ID: mdl-28584254

ABSTRACT

Chronic lymphocytic leukaemia (CLL) consists of two biologically and clinically distinct subtypes defined by the abundance of somatic hypermutation (SHM) affecting the Ig variable heavy-chain locus (IgHV). The molecular mechanisms underlying these subtypes are incompletely understood. Here, we present a comprehensive whole-genome sequencing analysis of somatically acquired genetic events from 46 CLL patients, including a systematic comparison of coding and non-coding single-nucleotide variants, copy number variants and structural variants, regions of kataegis and mutation signatures between IgHVmut and IgHVunmut subtypes. We demonstrate that one-quarter of non-coding mutations in regions of kataegis outside the Ig loci are located in genes relevant to CLL. We show that non-coding mutations in ATM may negatively impact on ATM expression and find non-coding and regulatory region mutations in TCL1A, and in IgHVunmut CLL in IKZF3, SAMHD1,PAX5 and BIRC3. Finally, we show that IgHVunmut CLL is dominated by coding mutations in driver genes and an aging signature, whereas IgHVmut CLL has a high incidence of promoter and enhancer mutations caused by aberrant activation-induced cytidine deaminase activity. Taken together, our data support the hypothesis that differences in clinical outcome and biological characteristics between the two subgroups might reflect differences in mutation distribution, incidence and distinct underlying mutagenic mechanisms.


Subject(s)
Genes, Immunoglobulin Heavy Chain/genetics , Immunoglobulin Heavy Chains/genetics , Immunoglobulin Variable Region/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Mutation/genetics , Aged , Aged, 80 and over , Cytidine Deaminase/genetics , Enhancer Elements, Genetic/genetics , Female , Humans , Male , Middle Aged , Promoter Regions, Genetic/genetics , Proto-Oncogene Proteins/genetics , SAM Domain and HD Domain-Containing Protein 1/genetics , Whole Genome Sequencing/methods
4.
Ann Oncol ; 26(5): 880-887, 2015 May.
Article in English | MEDLINE | ID: mdl-25732040

ABSTRACT

BACKGROUND: Glioblastoma (GBM) is the most common malignant brain cancer occurring in adults, and is associated with dismal outcome and few therapeutic options. GBM has been shown to predominantly disrupt three core pathways through somatic aberrations, rendering it ideal for precision medicine approaches. METHODS: We describe a 35-year-old female patient with recurrent GBM following surgical removal of the primary tumour, adjuvant treatment with temozolomide and a 3-year disease-free period. Rapid whole-genome sequencing (WGS) of three separate tumour regions at recurrence was carried out and interpreted relative to WGS of two regions of the primary tumour. RESULTS: We found extensive mutational and copy-number heterogeneity within the primary tumour. We identified a TP53 mutation and two focal amplifications involving PDGFRA, KIT and CDK4, on chromosomes 4 and 12. A clonal IDH1 R132H mutation in the primary, a known GBM driver event, was detectable at only very low frequency in the recurrent tumour. After sub-clonal diversification, evidence was found for a whole-genome doubling event and a translocation between the amplified regions of PDGFRA, KIT and CDK4, encoded within a double-minute chromosome also incorporating miR26a-2. The WGS analysis uncovered progressive evolution of the double-minute chromosome converging on the KIT/PDGFRA/PI3K/mTOR axis, superseding the IDH1 mutation in dominance in a mutually exclusive manner at recurrence, consequently the patient was treated with imatinib. Despite rapid sequencing and cancer genome-guided therapy against amplified oncogenes, the disease progressed, and the patient died shortly after. CONCLUSION: This case sheds light on the dynamic evolution of a GBM tumour, defining the origins of the lethal sub-clone, the macro-evolutionary genomic events dominating the disease at recurrence and the loss of a clonal driver. Even in the era of rapid WGS analysis, cases such as this illustrate the significant hurdles for precision medicine success.


Subject(s)
Brain Neoplasms/genetics , Chromosomes, Human , Glioblastoma/genetics , Isocitrate Dehydrogenase/genetics , Mutation , Adult , Antineoplastic Agents, Alkylating/therapeutic use , Brain Neoplasms/enzymology , Brain Neoplasms/pathology , Brain Neoplasms/therapy , Chemotherapy, Adjuvant , Cyclin-Dependent Kinase 4/genetics , Dacarbazine/analogs & derivatives , Dacarbazine/therapeutic use , Disease Progression , Fatal Outcome , Female , Genetic Association Studies , Genetic Predisposition to Disease , Glioblastoma/enzymology , Glioblastoma/pathology , Glioblastoma/therapy , Humans , Imatinib Mesylate/therapeutic use , Neoplasm Grading , Neoplasm Recurrence, Local , Neurosurgical Procedures , Phenotype , Protein Kinase Inhibitors/therapeutic use , Proto-Oncogene Proteins c-kit/genetics , Receptor, Platelet-Derived Growth Factor alpha/genetics , Temozolomide , Time Factors , Treatment Outcome
5.
J Nutr Health Aging ; 12(8): 520-9, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18810298

ABSTRACT

Alzheimer's disease (AD) is the most frequent form of dementia and according to the most recent estimation it affects nearly 27 million people in the world. The onset of the disease is generally insidious. It is becoming increasingly evident that the underlying pathophysiological mechanisms are active long before the appearance of the clinical symptoms of the disease. In the current context, it is important to develop strategies to delay the onset of cognitive decline. Delaying the onset by 5 years would reduce the prevalence by half at term, and a delay of 10 years would reduce it by three-quarters. The effectiveness of currently suggested preventive approaches remains to be confirmed, but certain strategies could be applied straight away to at-risk subjects. We propose that a health-promoting memory consultation should be set up for elderly persons who have attended a specialized memory consultation and in whom the diagnosis of dementia and of AD in particular, has not been established by standardized tools. Through this consultation, they would be offered full multidimensional investigation of all aspects of their health status, follow-up could be organized, general practitioners in private practice could be made more conscious of this population and the elderly could be made more aware of the risk factors to which they are exposed. The development of an information policy for the elderly would meet a present need. In our reflection, we must take into account the question of how to give this preventive consultation its due place in the healthcare pathway of the elderly person in order to ensure coordinated follow-up with all the other health professionals involved. The principle of the health-promoting memory consultation is undergoing validation in a large French multicentre preventive trial in 1200 frail elderly persons aged 70 years followed for three years, the Multidomain Alzheimer Preventive Trial (MAPT).


Subject(s)
Aging/psychology , Dementia/prevention & control , Health Services for the Aged/organization & administration , Memory Disorders/prevention & control , Memory/physiology , Aged , Aged, 80 and over , Ambulatory Care Facilities , Disease Progression , Female , Health Promotion , Humans , Male , Mass Screening , Memory Disorders/epidemiology , Memory Disorders/physiopathology , Referral and Consultation , Risk Factors
6.
Rev Neurol (Paris) ; 161(10): 949-56, 2005 Oct.
Article in French | MEDLINE | ID: mdl-16365624

ABSTRACT

INTRODUCTION: A national survey has been conducted with 349 general practitioners in order to analyze the management of concerned episodic headache in general practice. METHOD: This survey enabled collection of data from 2537 headache patients. The main data concered IHS diagnosis, severity of headache using the MIGSEV scale, management, practices and the impact on daily living (QVM and HIT-6 scales). RESULTS: Out of the 2537 included patients, 52 percent were migraine sufferers according to IHS criteria (code 1.1/1.2), 34 percent presented with migrainous disorders (code 1.7), and 14 percent were non-migraine headache patients. The distribution of management practices showed that 71 percent of them were given non-specific treatments, 46 percent of them specific treatments and 27 percent of them prophylactic treatments. Analysis of the impact of headache using the QVM or the HIT-6 demonstrated a relationship between diagnosis, migraine severity and disability. Analysis of the correlation between the severity of the last migraine attack as evaluated by the patient and that estimated by the doctor showed that the practitioner tended to underestimate the patient's pain. These results highlight the importance of communication between practitioners and migraine sufferers. CONCLUSION: Training of general practitioners in the use of simple tools such as the HIT-6 scale, should be helpful for a better evaluation of the impact of headache on daily living, and hence should lead to more optimal therapeutic management of headache patients.


Subject(s)
Migraine Disorders/therapy , Adult , Cross-Sectional Studies , Family Practice , Female , France , Humans , Male , Middle Aged , Migraine Disorders/epidemiology , Practice Patterns, Physicians' , Surveys and Questionnaires
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