The optimal way to detect and treat cancer is to target cancer cells exclusively without affecting the surrounding tissue. One promising approach is to use radiolabelled molecules to target receptors that are overexpressed in cancer cells. Since the epidermal growth factor receptor (EGFR) family is overexpressed in many types of cancer, it is an attractive target for both diagnostic and therapeutic applications. This thesis can be divided into two parts. In part one (paper I), studies were conducted to modulate radionuclide uptake in tumour cells. The results showed that it was possible to modulate the cellular uptake of 125I delivered by trastuzumab (targeting HER2) by adding EGF (targeting EGFR). In part two (papers II-V) a high affinity EGFR-targeting affibody molecule (ZEGFR:955)2 was selected and analysed both in vitro and in vivo. In papers II, III and V, the results obtained when using (ZEGFR:955)2 were compared with those obtained with the two EGFR-binding molecules, EGF and cetuximab. These studies demonstrated that the affibody molecule bound specifically to EGFR (probably to subdomain III) with high affinity (~50 nM in biosensor analysis and ~1 nM in cellular studies) and produced intracellular signalling changes similar to those with cetuximab. In paper IV, in vivo studies were made, demonstrating that [111In](ZEGFR:955)2 gave a tumour-specific 111In uptake of 3.8±1.4% of injected dose per gram tumour tissue, 4 h post-injection. The tumours could be easily visualized with a gamma camera at this time-point. The results of these studies indicated that the affibody molecule (ZEGFR:955)2 is a possible candidate for radionuclide-based imaging of EGFR-expressing tumours. The biological effects of (ZEGFR:955)2 might be of interest for therapy applications.

Abnormal expression and signaling of the ErbB receptors is associated with the development and progression of several forms of cancer. In this thesis, new ErbB-targeting affibody molecules are evaluated regarding their cellular effects in vitro. Since ligand binding to an ErbB receptor might have an impact on the cell it is important to be aware of these effects as they may have consequences for the continued growth of the tumor when used in vivo. The affibody molecules are intended for tumor targeting with the prospect of clinical use in imaging or therapy. Three types of affibody molecules were studied, HER2-binding, EGFR-binding and bispecific binders that target both EGFR and HER2. The HER2-targeting (ZHER2:342)2 showed promising characteristics. It sensitized SKBR-3 cells to irradiation and decreased cell growth to the same extent as the clinically approved antibody Herceptin. The monomeric version, ZHER2:342, did not induce any large effects on intracellular signaling or biological outcome. This makes (ZHER2:342)2 interesting for therapy purposes, while ZHER2:342 may be better suited for imaging. The bispecific affibody molecules were all able to simultaneously bind to both EGFR and HER2, but none of the six constructs resulted in any large effects on cellular outcome. Interestingly, all three monovalent binders are more functional when positioned at the N-terminal part of the construct and the (S4G)3 linker renders higher affinity of the bispecific binders compared to (G4S)3. Tumors that co-express several ErbB receptors are often more aggressive and associated with a worse prognosis, suggesting that the total ErbB expression pattern might be more informative than the expression level of one receptor regarding cancer prognosis and prediction of response to targeted therapies. Bispecific ligands could thus be used as imaging agents with prognostic value. Another aspect of dual targeting is the possibility of increased tumor specificity since tumors are more likely than healthy tissue to express high amounts of two receptors.

Engineered nanoparticles provide potential opportunities for improving current drug delivery, bioimaging and biosensing modalities. In many cases, a ligand, such as a protein, peptide or nucleic acids, is attached to the nanoparticles surface to serve as a targeting group. However, the nanoconjugation (i.e. covalently bound molecules to a nanocarrier) is not an innocuous reaction. It can change the binding affinity and interfere with the intracellular trafficking of the tethered species. The understanding of this influence to the tethered species is still lacking. Therefore, the main objective of this thesis is to investigate the effect of nanoconjugation to the biological identity of the tethered biomolecules, in terms of cellular uptake, intracellular trafficking and the ultimate biological outcomes. The Epidermal Growth Factor Receptor (EGFR) is a tyrosine kinase that regulates cell proliferation and can cause cancer if dysregulated. Continuous treatment with high doses of EGF can induce apoptosis, in EGFR overexpressing cell lines. In this thesis, Epidermal Growth Factor (EGF) was chosen as the object of investigation. Covalent attachment of EGF to gold nanoparticles (NP-EGF) was found to enhance apoptosis in EGFR overexpressing cell lines (A431, MDA-MB-468) and it is sufficient to induce apoptosis in cell lines exhibiting EGFR expression at physiological levels (HeLa). NP-EGF accumulation through the endosomal pathway was also investigated to assess the impact of nanoconjugation on the spatio-temporal distribution of NP-EGF as potential origin for the observed enhancement of apoptosis. Two orthogonal experimental approaches were applied: (1) isolation of NP-EGF containing endosomes by taking advantage of the increased density of endosomes associated with the uptake of Au NPs; (2) correlated darkfield/fluorescence imaging to map the spatial distribution of NP-EGF in endosomes as a function of time. The studies reveal that nanoconjugation prolongs the dwelling time of phosphorylated receptors in the early endosomes and that the retention of activated EGFR in the early endosomes is accompanied by an EGF mediated apoptosis at effective concentrations that do not induce apoptosis in the case of the free EGF. Investigating the nanoconjugation-enhanced EGF-induced apoptosis improves the current understanding of cell-nanomatieral interactions and provides new opportunities for overcoming apoptosis evasion by cancer cells. / 2017-01-01T00:00:00Z

L’adénocarcinome pancréatique canalaire est un cancer de mauvais pronostic avec une survie à 5 ans inférieure à 5% et une médiane de survie d’environ 6 mois. Dès les stades précoces de la carcinogenèse pancréatique, la mucine membranaire MUC1, glycoprotéine de haute masse moléculaire, est surexprimée et présente des anomalies de distribution cellulaire, essentiellement une délocalisation membranaire vers le pôle basolatéral et une rétention à l’intérieur de la cellule. Sachant que MUC1 est capable d’interagir avec l’EGFR et de jouer un rôle sur la transduction des signaux, cette séquestration pourrait être à l’origine de signaux oncogéniques et est utilisée par les pathologistes comme indicateur de malignité après ponction sur des lésions pancréatiques. Cependant, les mécanismes permettant cette rétention cytoplasmique ne sont pas connus. Des études antérieures du laboratoire ont montré que le trafic de certaines glycoprotéines vers la membrane apicale des cellules épithéliales était dépendant de la Galectine 4. Dans ce travail, nous nous intéresserons à la Galectine 3, lectine endogène susceptible d’interagir avec les motifs glycanniques des mucines et aussi des récepteurs membranaires. Cette Galectine est surexprimée dans le cancer pancréatique et son expression est corrélée à une forte agressivité tumorale dans d’autres cancers. Le but de ce travail a été dans un premier temps de mettre au point des lignées cellulaires pancréatiques polarisées CAPAN-1 Knocked-down pour la Galectine-3. Dans un second temps d’étudier l’implication de la Galectine-3 : (i) dans le trafic intracellulaire de MUC1 et l’EGFR (ii) dans l’interaction entre MUC1 et l’EGFR (iii) sur les voies de signalisation de l’EGFR.Les résultats montrent que les cellules tumorales pancréatiques CAPAN-1 présentent les anomalies de distribution cellulaire de MUC1 observées dans les tumeurs pancréatiques humaines, notamment la rétention de MUC1 à l’intérieur des cellules. Le silencing de la Galectine-3 entraîne la disparition de cette anomalie de distribution cellulaire, MUC1 retrouvant la distribution membranaire normale. Nous avons montré que l’inhibition de l’expression de la Galectine-3 est associée (i) à une augmentation de la translocation nucléaire de l’EGFR (ii) à une inhibition de l’endoyctose de MUC1 et de l’EGFR en condition de sevrage. Ce phénomène s’accompagne d’une augmentation de l’interaction entre MUC1 et l’EGFR et d’une activation accrue de ce récepteur tyrosine kinase lorsqu’il est soumis à l’EGF : augmentation de la phosphorylation de l’EGFR et augmentation de la phosphorylation des MAPK Erk1 et 2. Mots clés : Galectine, Mucine, EGFR, cancer, endocytose, translocation nucléaire / Pancreatic ductal adenocarcinoma (PDAC) is thought to derive from the epithelial ductal cells. In physiological state, the transmembrane mucin MUC1 is expressed at the apical pole where it protects the cell, senses the environment and modulates signal transduction notably by interacting with EGFR. In tumor cells, the localization of MUC1 is modified. MUC1 expression at the membrane becomes circumferential and accumulates in the cytoplasm. This sequestration is thought to deliver oncogenic signals to the cell, and is used by pathologists as an indicator of malignancy. Since it was previously demonstrated that endogenous lectins, especially galectin-3 (Gal-3) and -4, control the apical targeting of glycoproteins in epithelial cells, our aim was to study the role of Gal-3 in the control of MUC1 expression topography in PDAC, and in the cell invasiveness in vitro. Results/expected results: In control cells, we observed a strong MUC1 labeling in cytoplasm as in pathologic conditions. MUC1 was partially co-localized with M6PR in late endosomes. In KD cells, invalidation of Gal-3 led to a strong decrease of MUC1 cytoplasmic labeling. Gal-3 down-regulation is associated with a decrease of both MUC1 and EGFR protein levels by WB. However, KD Gal-3 cells expressed 2-fold higher levels of phosphoY1173EGFR in response to EGF treatment. Preliminary results showed that KD Gal-3 cells lost their in vitro invasive phenotype.Conclusions: Our data showed that Gal-3 is responsible for MUC1 cytoplasmic retention in pancreatic tumor cells. Silencing of Gal-3 promotes MUC1 localization at the cell membrane, and increases EGF-induced EGFR phosphorylation.keywords : Galectine, Mucine, EGFR, cancer, endocytose, translocation nucléaire

Le récepteur de facteur de croissance épidermique (EGFR) est une cible commune de thérapie anticancéreuse. Aujourd'hui, la recherche de nouvelles molécules inhibitrices de ce récepteur se tourne vers des substances naturelles. Un des composés naturels les plus prometteurs qui ont montré une activité anti-EGFR est la curcumine, un polyphénol présent dans les rhizomes de Curcuma longa. Il y a de nombreux rapports décrivant son effet sur l'activité kinase du récepteur, le rendement d'autophosphorylation, le niveau d'expression et les processus liés à la fonction EGFR comme la prolifération cellulaire. Néanmoins, l'ensemble des mécanismes d’intercation de la curcumine avec l'de l'EGFR n’est pas entièrement élucidée. Nous avons démontré que le mode d'action de la curcumine est double. La curcumine est capable d'inhiber partiellement, mais directement l'activité enzymatique du domaine intracellulaire de l'EGFR. Mais le travail présenté attire l'attention sur le rôle de l'environnement de la membrane de l'EGFR au niveau d'action de la curcumine. Nous avons montré que l'insertion de curcumine dans la membrane plasmique aboutit à sa rigidification et par conséquent la limitation de la diffusion du récepteur. Le suivi de particules à l'unité analyses a confirmé que le coefficient de diffusion de l'EGFR dans la membrane des cellules cancéreuses diminué de manière significative en présence de la curcumine, susceptibles d'influencer la dimérisation du récepteur et l'activation tour à tour. / Epidermal Growth Factor Receptor (EGFR) is a common target of anticancer therapy. Nowadays the search for new molecules inhibiting this receptor is turning towards natural substances. One of the most promising natural compounds that have shown an anti-EGFR activity is curcumin, the polyphenol found in the rhizomes of Curcuma longa. There are numerous reports describing its effect on the receptor kinase activity, the autophosphorylation yield, the expression level and the processes related to EGFR function like cell proliferation. Nevertheless, the entire mechanism of how curcumin interact with the EGFR is not fully elucidated. We demonstrated that the mode of action of curcumin is dual. Curcumin is able to inhibit directly but partially the enzymatic activity of the EGFR intracellular domain. But the presented work brings attention to the role of the EGFR membrane environment at the curcumin action level. We showed that the curcumin insertion in plasma membrane leads to its rigidification and as a consequence to limitation of the receptor diffusion. Single particle tracking analyses confirmed that the diffusion coefficient of EGFR in the cancer cell membrane significantly decreased in the presence of the curcumin, which might influence the receptor dimerization and in turns its activation.

Globally, breast cancer is the leading cause of death in the female population aged 45 and below with a breast cancer incidence reaching 18.1 million in the year 2018. Triple negative breast cancer (TNBC) is part of a group of cancers that lack the expression of Progesterone receptor (PR), Estrogen receptor (ER) and Human epidermal growth factor receptor 2 (HER2). TNBC is commonly associated with early stage metastasis with low survival rates as well as a high frequency of recurrence and proves to be problematic in both the young and elderly female populations. Conventional diagnostic methods for TNBCs include mammography, magnetic resonance imaging (MRI) and ultrasound while therapeutic methods include mastectomy and breast conserving surgery (coupled with radiation therapy). The lack of effective therapeutic options, poor prognostic value and high rates of metastasis, has made treatment of TNBC difficult. The major focus of this work was on the following tumour associated antigens (TAAs): CSPG4 (a transmembrane protein found in 50% of TNBC cases), EGFR (which is overexpressed in 13-76% of TNBCs), and MSLN (which is overexpressed in 67% of TNBCs) as potential targets for monospecific therapy. The evolution of antibody-based immunotherapy strategies has led to applications of single chain variable fragment (scFv) & single domain/nanobody (VHH) antibody formats for diagnostic and therapeutic purposes. In this work, these recombinant antibody fragments have been combined with SNAP-tag, a modified version of the human DNA repair enzyme O6-alkylguanine-DNA-alkyltransferase (AGT), which autocatalytically binds benzyl-guanine modified substrates such as fluorophores or small molecule toxins covalently in a 1:1 stoichiometry. In this study, the primary aim was the comparison of different antibody formats fused to SNAPtag and the potential of these biopharmaceuticals towards immunodiagnosis and therapy of TNBCs. First functionalities of two scFv SNAP fusion proteins and one VHH SNAP fusion protein previously not having been described are provided through binding analyses on receptor positive tumour cell lines. This was achieved by in-silico design and molecular cloning of genetically fused antiCSPG4(scFv), -MSLN(scFv), -MSLN(VHH), -EGFR(scFv) & -EGFR(VHH) to SNAP-tag. The final constructs were confirmed by Sanger sequencing and subsequently transfected into a mammalian vector system (HEK293T) for transient expression of the engineered fusion proteins. Full length protein purified from cell culture supernatant was analysed for diagnostic/therapeutic activities dependant on the substrate attached in the form of a fluorophore or small molecule toxin resulting in recombinant antibody-drug conjugates (ADCs). The study shows promise in providing new immunodiagnostic and therapeutic agents that are specific and less harmful than the current state of the art procedure

京都大学 / 0048 / 新制・課程博士 / 博士(薬学) / 甲第19654号 / 薬博第824号 / 新制||薬||240(附属図書館) / 32690 / 京都大学大学院薬学研究科薬学専攻 / (主査)教授 松原 和夫, 教授 中山 和久, 教授 金子 周司 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM

This cross-sectional study aims to evaluate the association of caffeine intake with renal function among adults between ages 18-55. Participants of the National Health and Nutritional Examination Survey (NHANES) survey for the three consecutive years (2013-2014, 2015-2016, and 2017-2018) were used. A weighted multivariable linear regression analysis of the caffeine concentration was conducted. Greater intake was associated with lowered renal function. This association persisted when limiting the daily caffeine intake to 2000 mg/day or less. Among younger adults, ages 18 to 39 the beta coefficient was about 50 percent larger than the beta coefficient for individuals ages 40 to 55. This suggests that caffeine intake may have a greater impact on renal function among younger adults. While greater caffeine intake was associated with reduced renal function in this cross-sectional study, further investigation such as an experimental study should be performed to confirm the findings of this thesis. / Epidemiology

Breast cancer is the major cause of cancer death among women worldwide. Understanding the mechanisms underlying breast cancer progression remains urgent for developing effective treatment strategies to eliminate breast cancer mortality. Our recent studies have demonstrated that Krüppel-like transcriptional factor 8 (KLF8) plays a critical role for breast cancer progression. Other studies have shown that Epithelial stromal interaction 1 (EPSTI1), a recently identified stromal fibroblast-induced gene in non-invasive breast cancer cells and epidermal growth factor receptor (EGFR) are highly overexpressed in aggressively invasive breast carcinomas including triple negative breast cancers. In this thesis project, we demonstrate high co-overexpression of KLF8 with EPSTI1 as well as EGFR in invasive breast cancer cells and patient tumors. We also show that KLF8 upregulates the expression of EPSTI1 by directly binding and activating the EPSTI1 gene promoter, and KLF8 upregulates the expression of EGFR not only by directly activating the EGFR gene promoter but also by preventing EGFR translation from microRNA141-dependent inhibition. Genetic, signaling and animal cancer model analyses indicate that downstream of KLF8, EPSTI1 promotes the tumor invasion and metastasis by activating NF-κB through binding valosin containing protein (VCP) and subsequent degradation of IκBα, whereas EGFR promotes tumor growth and metastasis via activation of ERK. Taken together, these data identify EPSTI1 and EGFR as novel iv KLF8 targets in breast cancer and suggest that KLF8 may be targeted for new effective treatment of breast cancer

No description available.