Mes travaux de thèse ont permis d’identifier nectine-4 comme un nouveau biomarqueur, facteur de pronostic et cible thérapeutique dans 63% des cancers du sein triple-négatif (TNBC). Les TNBCs (20% des cancers du sein) sont de mauvais pronostics car, en dehors de la chimiothérapie, il n’existe pas de traitement dit « ciblé ». Ces travaux vont permettre à court terme d’adapter la stratégie thérapeutique et d’améliorer la prise en charge des patientes TNBC en fonction de leur profil d’expression de nectine-4. En effet, nous proposons une thérapie ciblée fondée sur la stratégie Antibody Drug Conjugate « ADC » anti-nectine-4 dans les TNBC équivalent au trastuzumab-emtansine dans le cancer du sein HER2+. Nous avons produit, sélectionné et validé cet outil thérapeutique innovant. Nous avons couplé cet anticorps à la monomethyl auristatin-E (MMAE) et testé son efficacité in vitro et in vivo en utilisant des modèles précliniques de souris PDX (Patient Derived Xenograft) greffées en conditions orthotopiques avec des tumeurs primaires TNBC. Nos résultats obtenus sur les tumeurs primitives et métastatiques sont très prometteurs, puisqu’il est possible de réduire voire de faire disparaitre la masse tumorale très rapidement après un seul traitement à la fois au niveau des tumeurs primitives, des métastases positives pour nectine-4. Cet anticorps anti-nectine-4 a fait l’objet d’un brevet international, a été humanisé et est en cours de développement clinique au sein d’une industrie pharmaceutique. Il est actuellement testé pour sa toxicité et son efficacité chez le singe cynomolgus. / Nectin-4 has been identified as a breast and ovarian biomarker at CRCM. Nectin-4 is a celladhesion molecule belonging to the immunoglobulin superfamily and is involved in ectodermaldevelopment in human. Nectin-4 has been recently identified as the epithelial receptor for themeasles virus. Together, this work has been rewarded by Inserm in 2012 (Prix del’Innovation). During my thesis, I have characterized nectin-4 as new prognosis biomarker andtherapeutic target in 63% of triple-negatif breast cancer (TNBC) . TNBCs represent 20% ofbreast cancer and are associated with poor prognosis as there is no exisiting targeted therapy.These results open the possibility for Antibody Drug Conjugate (ADC)-based targetedtreatment of primary and advanced TNBCs similar to trastuzumab-emtansine for HER2-positive breast cancers. We selected and validated a monoclonal antibody against nectin-4ectodomain and developed an ADC conjugated to monomethyl auristatin-E (MMAE). Weassessed the therapeutic efficiency of this ADC in vitro and in vivo in localised and metastaticTNBC Patient derived Xenografts (PDXs). In vivo, this ADC induced rapid, complete anddurable responses on nectin-4-positive xenograft TNBC samples including primary tumours,metastatic lesions, and local relapses. This antibody has been humanized, patented and iscurrently under clinical development by a pharmaceutical company testing toxicity and efficacyin cynomolgus monkeys.

Philosophiae Doctor - PhD / There are over 100 different types of cancer, and each of these cancers are classified by the type of cell that it initially affects. For the purpose of this research we will be focussing on prostate cancer (PC). Prostate cancer is the second most common form of cancer in men around the world and annually approximately 4500 men in South Africa are diagnosed making PC a global epidemic. Prostate cancer is a type of cancer which starts in the prostate it is normally a walnut-sized gland found right below the bladder. PC follows a natural course, starting as a tiny group of cancer cells that can grow into a tumour. In some men if PC is not treated it may spread to surrounding tissue by a process called direct invasion/ spread and could lead to death. Current diagnostic tests for prostate cancer have low specificity and poor sensitivity. Although many PC's are slow growing there is currently no test to distinguish between these and cancers that will become aggressive and life threatening. Therefore the need for a less invasive early detection method with the ability to overcome the lack of specificity and sensitivity of current available diagnostic test is required. Biomarkers have recently been identified as a viable option for early detection of disease for example biological indicators ie. DNA, RNA, proteins and microRNAs (miRNAs). Since first described in the 1990s, circulating miRNAs have provided an active and rapidly evolving area of research that has the potential to transform cancer diagnostics and prognostics. In particular, miRNAs could provide potentially new biomarkers for PC as diagnostic molecules. Circulating miRNAs are highly stable and are both detectable and quantifiable in a range of accessible bio-fluids, having the potential to be useful as diagnostic, prognostic and predictive biomarkers. In this study we aimed to identify miRNAs as potential biomarkers to detect and distinguish between various types of PC in its earliest stage. The major objectives of the study were to identify miRNAs and their gene targets that play a critical role in disease onset and progression to further understand their mechanism of action in PC using several in silico methods, and to validate the potential diagnostic miRNAs using qRT-PCR in several cell lines. The identification of specific miRNAs and their targets was done using an "in-house" designed pipeline. Bioinformatic analyses was done using a number of databases including STRING, DAVID, DIANA and mFold database, and these combined with programming and statistical analyses was used for the identification of potential miRNAs specific to PC. Our study identified 40 miRNAs associated with PC using our "in-house" parameters in comparison to the 20-30 miRNAs known to be involved in PC found in public databases e.g. miRBase. A comparison between our parameters and those used in public databases showed a higher degree of specificity for the identification PC-associated miRNAs. These selected miRNAs were analysed using different bioinformatics tools, and were confirmed to be novel miRNAs associated with PC. The identified miRNAs were experimentally validated using qRT-PCR to generate expression profiles for PC as well as various other cancers. Prostate lines utilised in this study included PNT2C2 (normal) which was compared to BPH1 (Benign) and LNCaP (Metastatic). In the study the expression profiles of eight potential miRNA biomarkers for the detection of PC was determined using qRT-PCR, and to distinguish PC from other cancers. QRT-PCR data showed that miRNA-3 and -5 were up-regulated in the BPH1 and LNCaP when compared to PNT2C2. In addition miRNA-8 was also shown to be up-regulated in LNCaP. Based on these results it was shown that a miRNA profile could be established to distinguish between BPH1 and the LNCaP prostate cell lines. The results suggest that one miRNA as a diagnostic marker may be sufficient to differentiate between different cancer cell lines. Furthermore by creating a unique profile for each cancer cell line by using a combination of miRNAs could be a suitable approach as well. Finally, it was shown that through the use of a single or combination of all eight miRNAs a unique profile for all the cancer cell lines tested in this study can be created. This is an important finding which could have potential diagnostic or prognostic implications in clinical practice.

Arsenic (As) exposure is associated with cancer, lung and cardiovascular disease, yet the mechanisms involved are not clearly understood. Elevated matrix metalloproteinase-9 (MMP-9) levels are also associated with these diseases, as well as with exposure to water As. Our objective was to evaluate the effects of dietary components of inorganic As (iAs) intake on serum MMP-9 concentration at differing levels of tap water As. In a cross-sectional study of 214 adults, dietary iAs intake was estimated from 24-h dietary recall interviews using published iAs residue data; drinking and cooking water As intake from water samples and consumption data. Aggregate iAs intake (food plus water) was associated with elevated serum MMP-9 in mixed model regression, with and without adjustment for covariates. In models stratified by tap water As, aggregate intake was a significant positive predictor of serum MMP-9 in subjects exposed to water As≤10 μg/l. Inorganic As from food alone was associated with serum MMP-9 in subjects exposed to tap water As≤3 μg/l. Exposure to iAs from food and water combined, in areas where tap water As concentration is ≤10 μg/l, may contribute to As-induced changes in a biomarker associated with toxicity.

Methotrexate (MTX) is an antagonist of folic acid metabolism that was initially designed to treat malignancies, including childhood leukemia. After its anti-inflammatory properties were discovered, use of MTX became widespread in the treatment algorithms for several autoimmune illnesses, including the inflammatory bowel diseases (IBD), Crohn’s disease (CD) and ulcerative colitis (UC). The specific cause(s) of IBD in general, and CD in specific, have not yet been fully elucidated. However, most investigators agree that the pathogenesis is likely due to a combination of genetic vulnerability and precipitating environmental exposures. Some of these identifiable modifiers include adherence to a low fiber diet, vitamin D deficiency, smoking, and an alteration in the diversity of the gut microbiome in response to viral or bacterial illness or antibiotic medications. Disease activity in patients with CD, particularly during clinical trials, is assessed using composite indices, including the Crohn’s Disease Activity Index (CDAI), Crohn’s Disease Endoscopic Index of Severity (CDEIS), and the Short Inflammatory Bowel Disease Questionnaire (SIBDQ). A wide range of medications is used to induce and maintain long-term remission in patients with active CD. These include corticosteroids, immunosuppressive agents (thiopurines and MTX) and several classes of biologics such as TNF-inhibitors, anti-IL-12/23 and anti-adhesion molecules. TNF-inhibitors are often used as first-line biologic therapies in patients with IBD because they have been in widespread use for over two decades and therefore afford the clinician a more data-driven consideration of risk to benefit ratio when discussing treatment options with their patients. However, there is a relatively high rate of primary non-response and acquired secondary loss of response to TNF-inhibitors. A secondary loss of response often results from the production of neutralizing antibodies, referred to as Antibodies to Infliximab (ATI). In response, concomitant low-dose oral MTX therapy has been employed by clinicians to reduce the immunogenicity of biologic therapy. In addition, previous studies have also demonstrated the efficacy of MTX monotherapy in maintaining clinical remission in patients with CD when delivered at relatively higher doses. However, there is no consensus on the proper dosing or route of administration (oral or parenteral) of MTX. This knowledge gap has resulted in inconsistent clinical practice across physicians and institutions. Pharmacologic studies have identified the metabolic pathways underpinning the mechanism of action of MTX. It is generally understood that MTX in its native form is free to move across cell membranes in a bidirectional manner. It is only after MTX has been glutamated (MTX-PG) that it is “caged” within the cell and can exert its effects. MTX can be glutamated on up to five discrete sites, each contributing to its stereospecificity and membrane permeability. A better understanding of this process may inform the development of rational dosing and pharmacokinetic-based treatment algorithms that provide patients with a sufficient MTX (and subsequently MTX-PG) level required to achieve anticipated clinical efficacy but not so high as to contribute undo morbidity to treated patients. Therefore, optimizing MTX/MTX-PG dosing can significantly advance the utility of this immunomodulatory pathway to treat IBD and other autoimmune disorders. MTX can be administered orally or parenterally, the latter being delivered by either subcutaneous or intramuscular injection. Previous studies have demonstrated increased bioavailability of the drug at higher doses when delivered via the parenteral route. The native form of MTX has a short half-life and is eliminated from the body within 24 hours. Instead, it is the active metabolites of MTX which are retained for more extended periods of time and are ultimately responsible for the anti-inflammatory effects in the body. A MTX molecule can have anywhere from 1 and 5 glutamyl groups attached to it, denoted as MTX-PG1, MTX-PG 2, MTX-PG3, MTX-PG 4, and MTX-PG 5. The mechanism(s) by which MTX-PG moieties contribute anti-inflammatory activity is not fully understood but remains an area of active research. Several studies have explored the association between disease activity and erythrocyte MTX-PG levels. While initial results were mixed, more recent prospective cohort studies in patients with Rheumatoid Arthritis (RA) found an inverse relationship between intracellular levels of longer-chain MTX-PG (MTX-PG3, MTX-PG4, and MTX-PG5) and disease activity. This finding has raised the possibility that monitoring MTX-PG levels could be used as a clinical tool to optimize MTX therapy for patients. However, several key issues persist, including high interpatient variability in MTX-PG levels. Similar studies in patients with CD have thus far been scarce. More prospective studies are needed to explore the utility of MTX-PG pharmacokinetics as a useful biomarker and clinical tool to develop an individualized approach to managing patients with Crohn’s disease.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / There is accumulating evidence for the role of brain-derived neurotrophic factor (BDNF) in the pathophysiology of depression. However, the role of BDNF in the pathophysiology of post-traumatic stress disorder (PTSD) remains controversial, and no study has assessed BDNF concentrations among pregnant women with PTSD. We examined early-pregnancy BDNF concentrations among women with PTSD with and without depression. A total of 2928 women attending prenatal care clinics in Lima, Peru, were recruited. Antepartum PTSD and depression were evaluated using PTSD Checklist—Civilian Version (PCL-C) and Patient Health Questionnaire-9 (PHQ-9) scales, respectively. BDNF concentrations were measured in a subset of the cohort (N = 944) using a competitive enzyme-linked immunosorbent assay (ELISA). Logistic regression procedures were used to estimate odds ratios (OR) and 95 % confidence intervals (95 % CI). Antepartum PTSD (37.4 %) and depression (27.6 %) were prevalent in this cohort of low-income pregnant Peruvian women. Approximately 19.9 % of participants had comorbid PTSD-depression. Median serum BDNF concentrations were lower among women with comorbid PTSD-depression as compared with women without either condition (median [interquartile range], 20.44 [16.97–24.30] vs. 21.35 [17.33–26.01] ng/ml; P = 0.06). Compared to the referent group (those without PTSD and depression), women with comorbid PTSD-depression were 1.52-fold more likely to have low (<25.38 ng/ml) BDNF concentrations (OR = 1.52; 95 % CI 1.00–2.31). We observed no evidence of reduced BDNF concentrations among women with isolated PTSD. BDNF concentrations in early pregnancy were only minimally and non-significantly reduced among women with antepartum PTSD. Reductions in BDNF concentrations were more pronounced among women with comorbid PTSD-depression. / Revisión por pares

Lung cancer surpasses all other causes of cancer-related deaths worldwide. Gene-expression microarrays have shown that differences in the cytologically normal bronchial airway can distinguish between patients with and without lung cancer. In research reported here, we have used microRNA expression in bronchial epithelium and gene expression in nasal epithelium to advance biological understanding of the lung-cancer "field of injury" and develop new biomarkers for lung cancer diagnosis. MicroRNAs are known to mediate the airway response to tobacco smoke exposure but their role in the lung-cancer-associated field of injury was previously unknown. Microarrays can measure microRNA expression; however, they are probe-based and limited to detecting annotated microRNAs. MicroRNA sequencing, on the other hand, allows the identification of novel microRNAs that may play important biological roles. We have used microRNA sequencing to discover novel microRNAs in the bronchial epithelium. One of the predicted microRNAs, now known as miR-4423, is associated with lung cancer and airway development. This finding demonstrates for the first time a microRNA expression change associated with the lung-cancer field of injury and microRNA mediation of gene expression changes within that field. The National Lung Screening Trial showed that screening high-risk smokers using CT scans decreases lung-cancer-associated mortality. Nodules were detected in over 20% of participants; however, the overwhelming majority of screening-detected nodules were non-malignant. We therefore need biomarkers to determine which screening-detected nodules are benign and do not require further invasive testing. Given that the lung-cancer-associated field of injury extends to the bronchial epithelium, our group hypothesized that the field of injury may extend farther up in the airway. Using gene expression microarrays, we have identified a nasal epithelium gene-expression signature associated with lung cancer. Using samples from the bronchial epithelium and the nasal epithelium, we have established that there is a common lung-cancer-associated gene-expression signature throughout the airway. In addition, we have developed a nasal epithelium gene-expression biomarker for lung cancer together with a clinico-genomic classifier that includes both clinical factors and gene expression. Our data suggests that gene expression profiling in nasal epithelium might serve as a non-invasive approach for lung cancer diagnosis and screening

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20969号 / 医博第4315号 / 新制||医||1026(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 戸口田 淳也, 教授 濵﨑 洋子, 教授 三森 経世 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21672号 / 医博第4478号 / 新制||医||1035(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 川上 浩司, 教授 古川 壽亮, 教授 上杉 志成 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

Head and neck squamous cell carcinoma (HNSCC) develops in mucous membranes that line the mouth, throat and sinuses. It is the sixth most common cancer worldwide with more than 600,000 new cases diagnosed every year. The 5 year survival of HNSCC patients is less than 50% after initial diagnosis, while median survival after relapse or metastasis is less than one year. Unfortunately, the prognosis of HNSCC has not changed in the last two decades, mostly due to the poor understanding of the mechanism of this disease. New therapeutic targets and agents are in urgent need.