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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
221

A prospective longitudinal observational study on the effectiveness of Chinese herbal medicine in advanced cancer patients.

January 2010 (has links)
Wong, Ka Yee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 177-189). / Abstracts in English and Chinese; includes Chinese. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgements --- p.v / Table of Contents --- p.vii / List of Appendices --- p.xi / List of Tables --- p.xii / List of Figures --- p.xiv / Abbreviations --- p.xvi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- General Introduction --- p.1 / Chapter 1.2 --- Background to the study --- p.2 / Chapter 1.2.1 --- Epidemiology of cancer --- p.2 / Chapter 1.2.1.1 --- Incidence and mortality in the World --- p.2 / Chapter 1.2.1.2 --- Incidence and mortality in Hong Kong --- p.4 / Chapter 1.2.2 --- Prevalence of Traditional Chinese Medicine (TCM) --- p.5 / Chapter 1.2.3 --- Prevalence of Traditional Chinese Medicine (TCM) in cancer --- p.6 / Chapter 1.2.4 --- Development of TCM in Hong Kong --- p.7 / Chapter 1.3 --- Theoretical rationale of the study --- p.8 / Chapter 1.4 --- Significance of the study --- p.11 / Chapter Chapter 2 --- Literature Review --- p.13 / Chapter 2.1 --- Introduction --- p.13 / Chapter 2.2 --- The concept of Advanced Cancer --- p.13 / Chapter 2.2.1 --- Pathology of Advanced Cancer --- p.14 / Chapter 2.2.1.1 --- Metastatic Cancer --- p.14 / Chapter 2.2.2 --- Sign and Symptoms of Advanced Cancer --- p.19 / Chapter 2.2.3 --- Diagnosis of Advanced Cancer --- p.19 / Chapter 2.2.4 --- Current Treatment for Advanced Cancer --- p.21 / Chapter 2.2.5 --- Limitation of Current Treatments --- p.24 / Chapter 2.3 --- Diagnosis and Treatment by TCM of Advanced Cancer --- p.26 / Chapter 2.3.1 --- (Advanced) Cancer from the TCM perspectives --- p.26 / Chapter 2.3.2 --- Diagnosis by TCM of Advanced Cancer --- p.27 / Chapter 2.3.3 --- Treatment by TCM of Advanced Cancer --- p.28 / Chapter 2.4 --- Current Evidences about the Clinical Effectiveness of TCM on Cancer Patients --- p.29 / Chapter 2.5 --- The concept of Health-related Quality of Life (HRQOL) --- p.35 / Chapter 2.5.1 --- The importance of HRQOL to cancer patients --- p.35 / Chapter 2.5.2 --- HRQOL instruments --- p.37 / Chapter 2.5.2.1 --- EORTC QLQ-C30 --- p.38 / Chapter 2.5.2.2 --- SF-36 --- p.39 / Chapter 2.6 --- Summary of Literature Review --- p.40 / Chapter 2.7 --- The research questions --- p.41 / Chapter 2.8 --- Research Hypotheses --- p.42 / Chapter 2.9 --- The design of TCM protocol --- p.42 / Chapter Chapter 3 --- Methodology --- p.45 / Chapter 3.1 --- Introduction --- p.45 / Chapter 3.2 --- Protocol --- p.45 / Chapter 3.2.1 --- Study Design --- p.46 / Chapter 3.2.2 --- Selection of Participants --- p.46 / Chapter 3.2.2.1 --- Inclusion criteria --- p.48 / Chapter 3.2.2.2 --- Exclusion criteria --- p.49 / Chapter 3.2.3 --- Sample size calculation --- p.50 / Chapter 3.2.4 --- Setting --- p.51 / Chapter 3.2.5 --- Interventions --- p.51 / Chapter 3.2.5.1 --- Treatment --- p.51 / Chapter 3.2.5.2 --- Medication and dose/dosage --- p.52 / Chapter 3.2.5.3 --- Treatment Assignment --- p.55 / Chapter 3.2.5.4 --- Concurrent Medications --- p.56 / Chapter 3.2.6 --- Procedure and Methods --- p.56 / Chapter 3.2.6.1 --- Informed Consent --- p.56 / Chapter 3.2.6.2 --- Documentation --- p.57 / Chapter 3.2.6.3 --- Assessment Procedure --- p.57 / Chapter 3.2.7 --- Outcome Measurements --- p.62 / Chapter 3.2.7.1 --- Survey Questionnaire --- p.62 / Chapter 3.2.7.2 --- Quality of life (QOL) instruments --- p.62 / Chapter 3.2.7.3 --- Global Ratings --- p.64 / Chapter 3.2.7.4 --- Physical Examination and Laboratory tests --- p.65 / Chapter 3.2.8 --- Safety Considerations --- p.66 / Chapter 3.2.8.1 --- Adverse Events (AE) --- p.66 / Chapter 3.2.8.2 --- Serious Adverse Event (SAE) --- p.66 / Chapter 3.2.8.3 --- Causality Assessment --- p.67 / Chapter 3.2.9 --- Ethical consideration --- p.68 / Chapter 3.2.10 --- Data Collection --- p.69 / Chapter 3.3 --- Data analysis --- p.69 / Chapter 3.4 --- Expected Outcomes of Study --- p.71 / Chapter Chapter 4 --- Results --- p.72 / Chapter 4.1 --- Study Progress --- p.72 / Chapter 4.2 --- The Participants --- p.72 / Chapter 4.3 --- Clinical characteristics and Socio-demographics of Participants --- p.75 / Chapter 4.4 --- Main Outcome - Quality of Life --- p.78 / Chapter 4.4.1 --- QLQ-C30 --- p.79 / Chapter 4.4.1.1 --- Scoring and Transforming of items into scales --- p.79 / Chapter 4.4.1.2 --- Changes of Individual Scale at Different Visits --- p.80 / Chapter 4.4.1.3 --- Clinical significance of Scales --- p.98 / Chapter 4.4.2 --- SF-36 --- p.104 / Chapter 4.4.2.1 --- Scoring and Transforming of items into scales --- p.104 / Chapter 4.4.2.2 --- Changes of Individual Scale at Different Visits --- p.104 / Chapter 4.4.2.3 --- SF-36 Summary Scales --- p.113 / Chapter 4.4.3 --- Correlation of QLQ-C30 and SF-36 --- p.115 / Chapter 4.5 --- Measurement of Physical examination --- p.117 / Chapter 4.5.1 --- Body Weight --- p.117 / Chapter 4.6 --- Measurement of Laboratory Blood tests --- p.118 / Chapter 4.6.1 --- "Comparison of CBC, RFT, LFT and LD" --- p.118 / Chapter 4.6.2 --- Tumor Markers --- p.120 / Chapter 4.7 --- Adverse Events and Serious Adverse Events --- p.121 / Chapter 4.8 --- Global Ratings --- p.123 / Chapter 4.8.1 --- Global Rating 1 - Severity of Disease --- p.123 / Chapter 4.8.2 --- Global Rating 2 - Global Disease Status --- p.124 / Chapter 4.8.2.1 --- Change in Global Disease Status --- p.125 / Chapter 4.8.2.2 --- Agreement between RCMP and clinician --- p.125 / Chapter 4.8.2.3 --- Patients' perception after treatment --- p.126 / Chapter 4.9 --- Distribution of TCM patterns and Chinese herbal medicines --- p.127 / Chapter 4.10 --- Survival Rate --- p.132 / Chapter 4.11 --- Conclusion --- p.133 / Chapter Chapter 5 --- Discussion --- p.135 / Chapter 5.1 --- Conclusion on findings --- p.135 / Chapter 5.2 --- Baseline profile of participants --- p.137 / Chapter 5.3 --- Feasibility of TCM on advanced cancer patients --- p.139 / Chapter 5.3.1 --- Recruitment of Participants --- p.139 / Chapter 5.3.2 --- Compliance of participants to the study schedule --- p.140 / Chapter 5.4 --- Health-related Quality of Life --- p.142 / Chapter 5.5 --- Safety of TCM --- p.149 / Chapter 5.6 --- Chinese medicine practitioner vs Western medicine doctor --- p.150 / Chapter 5.7 --- TCM pattern differentiation and treatment --- p.151 / Chapter 5.8 --- Implication of study --- p.154 / Chapter 5.8.1 --- Clinical implication --- p.154 / Chapter 5.8.2 --- Policy implication --- p.154 / Chapter 5.9 --- Limitations of the study --- p.155 / Chapter 5.10 --- Recommendations for further studies --- p.157 / Chapter 5.11 --- Overall Conclusion --- p.158 / Appendices --- p.160 / References --- p.177
222

The implementation of new health protection scheme in Hong Kong in relationship to expensive chemotherapy

Zhao, Zhong Ai, Joanne., 趙仲愛. January 2012 (has links)
Background: As in the rest of the world, cancer has been a leading killer in Hong Kong. Though technology has been growing rapidly, expensive cancer treatments have continuously been problematic to patients and their families. There are some known risk factors that make some people have a higher risk for cancer than others, but the reason why some develop cancer and some do not is mostly still unknown. In addition, the expensive cancer treatments can distress patients and their families psychologically during the painful and long chemotherapy process which is a common cancer treatment. While it is important for experts to research on effective cancer treatment, it is also important for the government and health care experts to solve associated financial problems. In response to help patients to ease their financial burden of expensive medical treatment, the Hong Kong government has proposed a new health protection scheme (HPS), “My Health, My Choice.” Objective: In this paper, a systematic review on different published literatures is conducted to analyze the prospective outcome of HPS and if it can help patients to ease their financial burden. Results and Discussion: The Health scheme provides a financial aid option for patients who suffer from chemotherapy through monthly premium. However, the implementation of this HPS seems to be difficult both on the patients’ and the providers’ sides. Case study of health care systems in US and Canada is included in this paper to find out what Hong Kong can learn from other countries with completely different payment systems would manage to deal with this problem. Australia which with a universal coverage health care system has also proposed a similar HPS plan aiming to help lower health care cost by increasing individual responsibility on medical expenses. However, it failed by lack of support from the general public. The Australian example would be used to criticize some essential elements that would contribute to the failure of the HPS, and how Hong Kong would use this example to yield a better proposal. Conclusion: As HPS might not be able to ease the burden on cancer patients in Hong Kong, it is suggested for government to allocate more effective and direct resources on helping cancer patients, especially those who are receiving chemotherapy or improve services through better primary care. However, the final outcome remains unknown, and the final option still depends on the ultimate need from the general public. / published_or_final_version / Public Health / Master / Master of Public Health
223

Multinuclear platinum anticancer therapeutics : insights into their solution chemistry and DNA binding interactions from NMR spectroscopy and molecular modelling

Ruhayel, Rasha A. January 2010 (has links)
In the 1980's, Nicholas Farrell developed a range of structurally distinct multinuclear Pt complexes that form long-range interstrand crosslinks (IXLs) in DNA. The dinuclear complex [{trans-PtCl2(NH3)}2-µ-(H2N(CH2)6NH2)]2+ (1,1/t,t) was the first of this series to show promising results, however, it was the trinuclear complex [{trans-PtCl2(NH3)}2-µ-trans-Pt(NH3)2(H2N(CH2)6NH2)2]4+ (1,0,1/t,t,t or BBR3464) that was chosen for clinical trials based on significantly increased cytotoxicity compared to 1,1/t,t and cisplatin. Molecular biology experiments have shown that 1,1/t,t exclusively forms IXLs in DNA in the 5'¿ 5' direction, whilst 1,0,1/t,t,t can form IXLs in both the 5'¿5' and 3'¿3' directions. Previously, 2D [1H,15N] HSQC NMR has been used to study the formation of 5'–5' 1,4–GG IXLs. The formation of 3'–3' 1,4–GG IXLs have been studied as part of this thesis. More recently, Pt complexes such as [{trans–PtCl2(NH3)}2{H2N(CH2)6(NH2(CH2)2NH2)(CH2)6NH2}]4+ (1,1/t,t–6,2,6) and [{trans–PtCl2(NH3)}2{H2N(CH2)6(NH2)(CH2)6NH2}]3+ (1,1/t,t–6,6), where the charged central Pt moiety of 1,0,1/t,t,t is replaced by a polyamine linker, have been developed in the Farrell group and show increased potency compared to 1,0,1/t,t,t. The complex 1,1/t,t 6,2,6 is a lead candidate currently undergoing Phase I clinical trials. Prior to the work presented in this thesis, little was known about the aquation chemistry or kinetics of DNA binding of these novel complexes. Reported in Chapter 3 is the study of the formation of 3'–3' 1,4–GG IXLs by both 1,0,1/t,t,t and 1,1/t,t in the duplex 5' {d(TATACATGTATA)2} (33–14XL) (pH 5.4, 298K). A combination of 1D 1H and 2D [1H, 15N] HSQC NMR experiments was used to directly compare the results with the stepwise formation of the 5'–5' 1,4–GG IXL with the previously studied duplex, 5' {d(ATATGTACATAT)2} (55–14XL), under the same conditions. Preassociation as well as aquation were similar, however, differences were observed at the monofunctional binding step with evidence for numerous monofunctional adducts. Both reactions did not yield a single 3'–3' 1,4–GG IXL, rather several adducts that could not be characterised. Molecular dynamics simulations of the 3'–3' 1,4–GG IXLs showed highly distorted lesions that may have implication in cellular repair processes.
224

Synthesis of chiral vicinal diamines and in vitro anticancer properties of their platinum(II) coordinates

Berger, Gilles 05 December 2013 (has links)
15N-based nuclear magnetic resonance techniques are considered very powerful to study the molecular properties of platinum-containing anticancer agents, these properties being responsible for the efficacy of the compounds, but also for the understanding of resistance mechanisms and toxicity. Therefore, the first part of the present work aimed to develop a new method for synthesizing 15N-labeled, chiral platinum compounds. A theoretical discussion on the nucleophilic ring-opening of aziridines has also been envisaged, rationalizing an interesting regiochemistry question. Indeed, a surprising inversion of regiochemistry arose during the development of the above-mentioned synthetic pathway, and density functional theory calculation brought a rational framework to the experimental findings.<p><p>Infrared spectroscopy probes the global chemical composition of a sample and has been used to produce a snapshot of cancer cells contents after treatment with platinum coordinates. Indeed, in vitro studies focused here on the use of modern spectroscopic methods to fingerprint the cellular impact of platinum complexes. These drug signatures help to classify and select promising compounds. It makes no doubt that such systemic approaches for compound discovery are helpful technologies. Also, we made the use of the COMPARE algorithm from the NCI, which analyzes similarity between any active compounds previously tested by the NCI large scale in vitro screening program of anticancer agents. <p><p>The last chapter aimed to study the interactions between a series of platinum coordinates and DNA. Binding mode to telomeric-like sequences and binding kinetics to genomic-like sequences were assessed to investigate any differences between the compounds and to gain insight into structure-activity relationships. <p> / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished
225

Caractérisation des propriétés anticancéreuses de la fusicoccine A et de l'ophioboline A au sein de modèles expérimentaux de glioblastomes humains / Characterization of the anticancer properties of fusicoccin A and ophiobolin A in experimental models of human glioblastoma

Bury, Marina 12 June 2013 (has links)
Le glioblastome est la plus fréquente et la plus agressive des tumeurs cérébrales primaires.<p>Malgré un traitement standard pluridisciplinaire (chirurgie, radiothérapie et chimiothérapie),<p>la médiane de survie des patients atteints de ce type de tumeur est de 15 mois et aucun patient<p>n’a pu être guéri à ce jour. Ce pronostic très sombre est directement lié à la capacité<p>d’invasion diffuse du parenchyme cérébral par les cellules gliales tumorales, ce qui rend<p>impossible une résection chirurgicale totale. De plus, ces cellules sont particulièrement<p>résistantes aux traitements chimiothérapeutiques de type pro-apoptotique, entrainant une<p>récidive quasi inévitable de la tumeur. De nombreuses stratégies thérapeutiques telles que<p>l’immunothérapie ou les thérapies ciblées sont actuellement explorées pour tenter de<p>combattre ces tumeurs. Cependant, leur efficacité au niveau clinique s’est avérée décevante. Il<p>devient donc indispensable d’identifier de nouveaux agents thérapeutiques afin d’améliorer la<p>survie des patients atteints de glioblastome.<p>Dans ce travail, nous avons caractérisé les propriétés anticancéreuses in vitro et in vivo de<p>deux terpénoïdes extraits de champignons, la fusicoccine A et l’ophioboline A, puis nous<p>avons caractérisé en partie leur mécanisme d’action anti-tumoral dans des cellules de<p>glioblastome.<p>Tout d’abord, nous avons montré que l’activité inhibitrice de croissance in vitro de la<p>fusicoccine A et de l’ophioboline A n’était pas dépendante du degré de sensibilité ou de<p>résistance à l’apoptose des cellules gliales tumorales. Nous avons ensuite mis en évidence que<p>la fusicoccine A était capable de diminuer l’invasion des cellules de glioblastome in vitro en<p>ciblant la kinase focale d’adhérence (FAK). Dans le même temps, nous avons démontré que<p>l’ophioboline A était capable d’induire la mort de ces cellules par paraptose en inhibant<p>l’activité du canal ionique BKCa. Ces deux cibles sont intéressantes car en plus d’être<p>surexprimées dans les glioblastomes, elles interviennent dans de nombreux processus<p>cellulaires tels que la prolifération, la migration et la survie cellulaire.<p>Pour finir, nous avons analysé le pouvoir anti-tumoral in vivo de ces deux terpénoïdes en<p>utilisant un modèle murin de mélanome métastatique, couramment utilisé dans notre<p>laboratoire. Seule l’ophioboline A, injectée en intrapéritonéal à 10 mg/kg, augmentait de<p>manière significative la survie des souris traitées avec cette molécule par rapport aux souris<p>contrôles. Dans ce premier modèle, nous n’avions pas déterminé les conditions optimales<p>9<p>pour l’évaluation in vivo de la fusicoccine A et de l’ophioboline A. Lorsque celles-ci seront<p>définies, des modèles de xénogreffes orthotopiques de glioblastomes humains implantées dans<p>le cerveau de souris immunodéficientes seront utilisés.<p>En conclusion, l’ophioboline A, pouvant être produite en quantités industrielles par culture<p>du champignon qui la synthétise, possédant un mécanisme d’action original et montrant déjà<p>un début d’activité in vivo, pourrait représenter une molécule méritant des études plus<p>approfondies en termes d’agent thérapeutique susceptible de combattre les glioblastomes. / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished
226

FTIR spectra of cancer cells exposed to anticancer drugs reflect their cellular mode of action / Spectres infrarouges de cellules cancéreuses exposées à des agents anticancéreux reflètent leur mode d'action dans les cellules

Derenne, Allison 17 May 2013 (has links)
There is an urgent need to develop reliable and cost-saving methods to select pre-clinically new drug candidates with original mechanism for cancer therapy. Previous results have shown that IR spectra of cancer cells exposed to various drugs provided a global signature of all the metabolic changes induced by the treatments. In this thesis, we attempted to develop a selection criterion – based on FTIR spectroscopy – for potential antitumor compounds according to their mechanism of action. <p>In chapter III, it was demonstrated that spectral variations in IR spectra of cancer cells induced by a treatment can be correlated to the mechanism of the drug. Human prostate cancer PC-3 cells were exposed to 7 well-described anticancer drugs belonging to 3 distinct classes. Each class is characterized by a unique mode of action. Drugs known to induce similar types of metabolic disturbances appear to cluster when spectrum shapes are analyzed. Chapter IV generalized the results obtained on PC-3 cells with six other cell lines. We showed that the spectral signatures of drug effects are mainly independent of the cell line. Chapter V indicated that, while the cell cycle phase influence IR spectra of cells, the drug spectral signature was dominated by global metabolic modifications and not much by the cell cycle perturbations due to this drug. <p>Chapter VI and VII focused on lipids. While the precise identification of particular molecules is particularly complex with IR spectroscopy, we attempted to extract more precise information and to assign spectral variations to specific changes in lipids. IR spectra of lipids contain very interesting details on their nature and structure. We achieved to build a tool which quantifies five major lipid classes in complex mixtures such as total lipid cell extracts. However, based on this tool, the treatments used do not induce any variation in the lipid cell composition (for five classes).<p>Finally, in chapter VIII, we applied the method developed previously on a new potential class of anticancer molecules: the polyphenols. A global method was particularly interesting as the development of therapy using these compounds is hampered by the complexity of the multiple anticarcinogenic mechanisms of these molecules. We have noticed the similarities and discrepancies among 3 very close synthetic molecules and the observations were coherent with previous biological data. We also compared them with 3 natural molecules already in clinical phase for treatment of various cancers.<p>In conclusion, we developed an objective classifier for potential anticancer drugs based on their global effects on cancer cells. Applied to a larger scale, this method could constitute a first step in the screening method to select drugs with original mode of action.<p>There is an urgent need to develop reliable and cost-saving methods to select pre-clinically new drug candidates with original mechanism for cancer therapy. Previous results have shown that IR spectra of cancer cells exposed to various drugs provided a global signature of all the metabolic changes induced by the treatments. In this thesis, we attempted to develop a selection criterion – based on FTIR spectroscopy – for potential antitumor compounds according to their mechanism of action. <p>In chapter III, it was demonstrated that spectral variations in IR spectra of cancer cells induced by a treatment can be correlated to the mechanism of the drug. Human prostate cancer PC-3 cells were exposed to 7 well-described anticancer drugs belonging to 3 distinct classes. Each class is characterized by a unique mode of action. Drugs known to induce similar types of metabolic disturbances appear to cluster when spectrum shapes are analyzed. Chapter IV generalized the results obtained on PC-3 cells with six other cell lines. We showed that the spectral signatures of drug effects are mainly independent of the cell line. Chapter V indicated that, while the cell cycle phase influence IR spectra of cells, the drug spectral signature was dominated by global metabolic modifications and not much by the cell cycle perturbations due to this drug. <p>Chapter VI and VII focused on lipids. While the precise identification of particular molecules is particularly complex with IR spectroscopy, we attempted to extract more precise information and to assign spectral variations to specific changes in lipids. IR spectra of lipids contain very interesting details on their nature and structure. We achieved to build a tool which quantifies five major lipid classes in complex mixtures such as total lipid cell extracts. However, based on this tool, the treatments used do not induce any variation in the lipid cell composition (for five classes).<p>Finally, in chapter VIII, we applied the method developed previously on a new potential class of anticancer molecules: the polyphenols. A global method was particularly interesting as the development of therapy using these compounds is hampered by the complexity of the multiple anticarcinogenic mechanisms of these molecules. We have noticed the similarities and discrepancies among 3 very close synthetic molecules and the observations were coherent with previous biological data. We also compared them with 3 natural molecules already in clinical phase for treatment of various cancers.<p>In conclusion, we developed an objective classifier for potential anticancer drugs based on their global effects on cancer cells. Applied to a larger scale, this method could constitute a first step in the screening method to select drugs with original mode of action.<p><p>Afin d’améliorer les thérapies contre le cancer, il devient actuellement cruciale de développer une méthode pour améliorer la sélection préclinique de nouvelles molécules, potentiellement anticancéreuses. Des publications précédentes ont mis en évidence que les spectres infrarouges de cellules cancéreuses exposées à différents agents thérapeutiques fournissent une empreinte globale de l’ensemble des changements métaboliques induit par ce médicament. Dans cette thèse, nous proposons d’utiliser la spectroscopie infrarouge pour mettre au point un critère de sélection basé sur le mode d’action des agents anticancéreux. Plusieurs aspects de la technique ont été investigués. Nous avons d’abord démontré la possibilité d’utiliser les spectres infrarouges de cellules cancéreuses de prostate PC-3 traitées avec 7 drogues pour classer ces molécules selon leur mode d’action. Nous avons ensuite reproduit les résultats obtenus sur PC-3 avec 6 autres lignées cellulaires et montré que la signature spectrale obtenue était largement indépendante de la lignée. Par la suite, nous avons étudié si l’effet sur le cycle cellulaire induit par de nombreuses molécules anticancéreuses, pouvait expliquer certains changements spectraux observés suite au traitement. Nous avons pu montrer que la majorité des variations spectrales n’étaient pas liées à une perturbation du cycle cellulaire. Nous nous sommes ensuite concentrés sur une classe de molécules en particulier: les lipides. Après avoir mis en évidence l’ensemble des informations contenues dans un spectre infrarouge de lipides, nous avons mis au point un modèle permettant de quantifier 5 classes de lipides dans des mélanges complexes tels que des extraits lipidiques provenant de cellules. Néanmoins, aucune variation du contenu en ces 5 classes de lipides n’a été observée pour les traitements utilisés dans cette étude. Enfin, nous avons appliqué la méthode mise au point dans cette thèse à une classe de molécules prometteuses :les polyphénols. Une approche globale s’avère particulièrement intéressante pour ces composés étant donné qu’ils présentent des mécanismes anticancéreux multiples et complexes. Nous avons comparé 3 molécules naturelles en phase clinique pour le traitement de certains cancers et 3 molécules synthétiques présentant une structure très proche. Par notre méthode, nous avons mis en évidence certaines similarités et différences de ces 6 molécules en termes d’effets globaux sur les cellules. En conclusions, nous avons développé un outil objectif de classification pour les molécules anticancéreuses potentielles, basée sur le mécanisme global des composés. Appliquée à plus large échelle, cette méthode pourrait constituer une première étape permettant de sélectionner les molécules avec un mode d’action original. / Doctorat en Sciences agronomiques et ingénierie biologique / info:eu-repo/semantics/nonPublished
227

Etude des mécanismes moléculaires et cellulaires impliqués dans la résistance anti-tumorale in vivo induite par le cyclophosphamide

Rahir, Gwendoline 23 April 2012 (has links)
Malgré la découverte des antigènes tumoraux depuis quelques décennies dans les mélanomes humains, l’immunothérapie anticancéreuse reste encore relativement inefficace. En outre, les traitements anti-tumoraux classiques tels que la chimiothérapie et la radiothérapie ont longtemps été considérés comme des traitements affectant principalement les cellules tumorales en division. Actuellement, des études de plus en plus nombreuses suggèrent que le succès de la chimiothérapie dépendrait, en partie, du système immunitaire. En effet, d’une part, les agents chimio-thérapeutiques pourraient induire une mort immunogène des cellules tumorales et donc potentialiser les réponses immunitaires. D’autre part, certains rapports montrent que la présence préalable de cellules immunes dans l’environnement tumoral améliore le pronostic clinique observé après chimiothérapie notamment.<p><p>Au cours de ce travail, nous avons étudié l’effet du cyclophosphamide (CTX, un agent alkylant) sur le système immunitaire et la résistance anti-tumorale dans des souris porteuses du mastocytome P815. Nous avons remarqué qu’une seule injection de CTX dans des souris inoculées 10-20 jours plus tôt avec une dose létale de cellules tumorales induit la survie dans 100% des souris traitées. En outre, le rejet tumoral induit par le CTX est strictement dépendant des lymphocytes T CD4+ et CD8+, et permet une résistance tumorale à long terme spécifique du mastocytome P815. Le but de cette étude était d’appréhender les mécanismes cellulaires et moléculaires impliqués dans cette mémoire spécifique de la tumeur. <p><p>Nous avons premièrement montré que le CTX augmente les réponses de type Th1 et Th17 dans des souris immunisées. L’activation de ces réponses requiert l’IL-12p40 et corrèle avec une augmentation du nombre de cellules CD11b+/F4/80+/Ly6C+, suggérant que ces DCs inflammatoires présumées pourraient être une source potentielle d’IL-12 et/ou d’IL-23. Des résultats similaires ont été observés dans des souris porteuses de la tumeur P815 et traitées au CTX. Nous avons également caractérisé les cellules T anti-tumorales effectrices qui infiltrent la tumeur et en particulier, nous avons étudié le rôle des cellules T auxiliaires CD4+ dans la migration des lymphocytes T CD8+ spécifiques de la tumeur. Nous avons observé que la déplétion des cellules T CD4+ semble induire un blocage des lymphocytes T CD8+ dans les ganglions drainant la tumeur qui ne migrent alors plus vers le foyer tumoral. Nous avons donc évalué le rôle de chimiokines/récepteurs aux chimiokines qui pourraient être impliqués dans ce processus tels que les couples CXCR3/CXCL9-10-11. <p><p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
228

Identification de nouvelles molécules à potentiel anticancéreux

Balde, Elhadj Saïdou 17 June 2010 (has links)
Les molécules actuellement utilisées dans la chimiothérapie anticancéreuse sont pour la majorité d’origine végétale mais peuvent aussi provenir d’organismes marins ou de microorganismes. Ces molécules bien qu’ayant des cibles moléculaires différentes, induisent dans la majorité des cas une mort cellulaire par apoptose. Or ces dernières années le développement d’une chimiorésistance des cellules cancéreuses vis à vis de ce type de molécules s’est particulièrement accru. Face à cette situation le besoin de trouver de nouvelles molécules avec des mécanismes d’action différents se fait de plus en plus pressant. Dans cette perspective nous avons évalué le potentiel anticancéreux des alcaloïdes du Pavetta crassipes K Schum, du Kalanchoe blossfeldiana Poelln, de l’isostrychnopentamine (ISP) isolée du Strychnos usambarensis Gills et de 14 phytotoxines d’origine fongique. Nous avons évalué leurs activités inhibitrices de croissance in vitro sur des lignées humaines cancéreuses de glioblastome (U373), d’oligodendrogliome (Hs-683), de poumon non à petite cellule (A549), de prostate (PC3), de sein (MCF7), d’œsophage (OE21), de mélanome (SKMEL-28) et des lignées murines de mélanome (B16F10) et de carcinome mammaire (MXT). Ces différentes lignées sont décrites dans la littérature comme ayant des niveaux variables de sensibilité aux molécules inductrices d’apoptose. Nous montrons ainsi dans notre travail que l’isostrychnopentamine ou encore des extraits issus de Pavetta crassipes K Schum ont in vitro des activités anticancéreuses intéressantes quelque soit la sensibilité de la lignée cellulaire aux stimuli pro-apoptotiques. De surcroit les lignées connues pour avoir un certain niveau de résistance à l’apoptose sont plus sensibles (IC50 ~ 1µM) aux effets de ces deux fractions que les lignées cancéreuses ou normales habituellement sensibles à l’apoptose (IC50 ~ 2,5µM). Les taux comparatifs d’apoptose induite par l’isostrychnopentamine dans 2 lignées dites résistantes à l’apoptose (U373 et A549) montrent une complète indépendance du taux de sensibilité à l’apoptose de ces lignées. Cette situation laisse penser que l’apoptose n’est pas le mécanisme d’action principale de la molécule. L’évaluation du potentiel anticancéreux des 14 phytotoxines d’origine fongique sur des lignées cellulaires de cancer humain et murin nous a permis de retenir deux phytotoxines (le bislongiquinolide et le dihydrotricodimerol) pour des investigations plus poussées. En effet les résultats obtenus en vidéomicroscopie indiquent que ces deux phytotoxines ont un effet cytostatique qui in fine conduit à un effet cytotoxique. / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished
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Anticancer ativities of topotecan-genistein combination in prostate cancer cells

Unknown Date (has links)
Prostate cancer is one of the leading causes of death in men aged 40-55. Genistein isoflavone (4', 5', 7-trihydroxyisoflavone) is a dietary phytochemical with demonstrated anti-tumor activities in a variety of cancers. Topotecan Hydrochloride (Hycamtin) is an FDA-approved chemotherapy drug, primarily used for secondary treatment of ovarian,cervical and small cell lung cancers. This study was to demonstrate the potential anticancer activities and synergy of topotecan-genistein combination in LNCaP prostate cancer cells. The potential efficacy and mechanism of topotecan/genistein-induced cell death was investigated... Results: The overall data indicated that i) both genistein and topotecan induce cellular death in LNCaP cells, ii) topotecan-genistein combination was significantly more efficacious in reducing LNCaP cell viabiligy compared to either genistein or topotecan alone, iii) in all cases, cell death was primarily through apoptosis, via the activation of the intrinsic pathway, iv) ROS levels were increased and VEGF expression was diminished significantly with the topotecan-genistein combination treatment, v) genetic analysis of topotecan-genistein treatment groups showed changes in genetic expression levels in pathway specific apoptotic genes.... Conclusion: Treatments involving topotecan-genistein combination may prove to be an attractive alternative phytotherapy of adjuvant therapy for prostate cancer. / by Vanessa P. Hèormann. / Thesis (Ph.D.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
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Bidirectional regulation of YAP and ALDH1A1

Martien, Matthew F. 10 August 2015 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Breast cancer is the second leading cause of cancer death for women in the United States. Approximately, 1 in 5 women will recur with cancer within 10 years of completing treatment and recent publications have suggested that breast cancer stem cells confer resistance to therapy. These reports highlight aldehyde dehydrogenase 1A1 (ALDH1A1) and Yes-associated protein (YAP) as a biomarker and key mediator of the stem cell phenotype respectively. To further understand how YAP and ALDH1A1 facilitate chemoresistance, this study investigated how ALDH1A1 specific inhibition affected YAP activity and growth of basal-like breast cancer cells, which are enriched in cancer stem cells. Intriguingly, attenuation of growth by ALDH1A1 inhibition was observed when cells were plated on a reconstituted basement membrane. Further, the inhibition of cell growth correlated with cytosolic retention of YAP and a reduction in YAP signaling. In a complementary analysis, the overexpression of YAP correlated with an increased level of ALDH1A1 transcript. Results from this study indicate a novel mechanism by which basal-like breast cancer cells utilize YAP to maintain the stem cell phenotype and also suggest ALDH1A1 as a potential therapeutic target for breast cancer therapy.

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