Changes to the metabolism of the cardiomyocyte are driven by complex signaling pathways in order to adjust to stress. For instance, HIF-1α is classically known to upregulate glycolytic metabolism to compensate for oxygen deficiency. Other important effects upon glucose metabolism, which we investigate here more extensively, were also observed. Hearts derived from mice with the cardiac-restricted expression of a stabilized form of HIF-1α are remarkably ischemia stress-tolerant. Here, stable isotope-resolved metabolomic analyses were utilized to investigate glucose cardiometabolism remodeling by HIF-1αduring ischemia. We found that 13C-lactate accumulation was significantly elevated in HIF-1α expressing hearts while paradoxically glycogen was maintained to a remarkable extent during an ischemic time course. These findings suggested an unexpected source of glucose in HIF-1α hearts during global ischemia. Accordingly, the presence of gluconeogenesis in hearts was evaluated. Indeed, gluconeogenic intermediates (i.e. m+3) including glucose-6-phosphate [m+3], fructose-6-phosphate [m+3], and fructose 1,6-bisphosphate [m+3] were observed at significantly elevated levels in the ischemic HIF-1α heart. Collectively, these data establish the surprising finding that HIF-1α supports active gluconeogenesis in the heart during ischemia. As less is known regarding the effects of CTRP3 we first tested whether CTRP3 overexpression would protect the ischemic heart. Our data indicate that CTRP3 failed to confer ischemic tolerance in heart ex vivo. However,we were able to show that CTRP3 protected the liver from lipid-induced stress and prevented hepatic lipid accumulation. To further investigate the mechanisms of hepatic protective effect mediated by CTRP3, we identified the receptor and established that CTRP3 increases oxygen consumption in response to lipid overloaded. Lysosomal-associated membrane protein 1 (LAMP-1), In summary, these data indicate that targeted metabolic rearrangements within cardiomyocyte/hepatocyte holds promise for the alleviation of common pathological conditions.

Le facteur de transcription HIF-1 est un hétérodimère composé d’une sous-unité α et d’une sous-unité ß. HIF-1 est capable de reconnaître une séquence consensus appelée HRE (HIF Response Element) et de réguler l’expression de plus de 200 gènes cibles impliqués dans divers mécanismes cellulaires. Nous nous intéressons à étudier le rôle de HIF-1α dans la peau, d’une part dans la régulation des enzymes de la réparation de l’ADN suite à l’irradiation UVB, d’autre part dans la physiologie cutanée.Nos résultats montrent bien que HIF-1α régule l’expression des gènes participant à la réparation de l’ADN (XPC et XPD). Ces gènes contiennent dans leurs régions promotrices des HRE de HIF-1α. La quantification de l’immunoprécipitation de chromatine révèle des HRE putatifs dans les gènes codant pour d'autres protéines de la réparation de l'ADN (XPB, XPG, CSA et CSB), ce qui suggère que HIF-1α est un régulateur clé de la machinerie de réparation de l'ADN. Nous avons prouvé que HIF-1α est indispensable à l’adhésion des kératinocytes par sa régulation exercée sur la laminine-332 et les intégrines (α6 et ß1). L’absence de l’expression de HIF-1α empêche aussi la reconstruction des épidermes à partir des kératinocytes humains. Nos résultats ont montré que les souris invalidées pour HIF-1α développent avec l’âge un phénotype d’inflammation dans plusieurs régions. Ces souris sont très sensibles au moindre stress consécutif à une blessure et une irradiation UVB. L’induction de l’inhibition de HIF-1α dans des souris inductibles avec le tamoxifène indique un détachement de l’épiderme au niveau des couches supra-basales. Ces souris meurent deux semaines après injection du tamoxifène / The transcription factor HIF-1 is a heterodimer composed of an α and ß subunit. HIF-1 is capable of recognizing a consensus sequence called HRE (hypoxia Response Element) and regulate the expression of more than 200 target genes involved in various cellular mechanisms. We are interested in studying the role of HIF-1α in the skin physiology.Our results show that HIF-1α regulates the expression of two main factors (XPC and XPD) involved in nucleotide excision repair through binding on HRE in their promoter regions. Quantitative chromatin immunoprecipitation assays further revealed putative HREs in the genes encoding other DNA repair proteins (XPB, XPG, CSA and CSB), suggesting that HIF-1α is a key regulator of the DNA repair machinery. We proved that HIF-1α is essential for keratinocyte adhesion through its regulation exerted on laminin-332 and integrins (α6, ß1). The lack of HIF-1α expression also prevents the reconstruction of epidermis by human keratinocytes. Our results showed that mice constitutively depleted for HIF-1α in their epidermis develop with age a phenotype of inflammation in several regions. These mice are very sensitive to the stress resulting from wound injury and UVB irradiation. HIF-1α depletion in the epidermis of inducible mice using tamoxifen results in a detachment of the epidermis in suprabasal layers. These mice die within two weeks after injection of tamoxifen

Einleitung: Ein häufiger Befund in routinemäßig untersuchten Bioptaten equiner Endometrien sind degenerative Alterationen der Blutgefäße in Form von Angiosklerosen. Sie stellen die Ursache einer endometrialen Minderperfusion dar und bedingen Fruchtbarkeitsstörungen. Ziele der Untersuchungen: Der Inhalt dieser Arbeit war die Untersuchung equiner Endometriumproben mit graduell vari-ablen Angiosklerosen. Die Hypothese ist, dass degenerative Gefäßwandveränderungen die Ursache für einen hypoxischen Zustand darstellen. Anhand der Expression von so genannten Hypoxiemarkern sollte das Vorliegen eines potenziellen Sauerstoffmangels in Folge einer Minderperfusion durch degenerative Blutgefäßwandveränderungen überprüft und immunhis-tologisch dargestellt werden. Des Weiteren sollten Zusammenhänge zu anderen Einflussfak-toren wie zum Beispiel dem Zyklusstand, dem Vorliegen einer Trächtigkeit, dem Alter oder einer Endometrose untersucht werden. Tiere, Material und Methoden: Grundlage für diese Untersuchungen waren vor allem equine Endometriumbioptate aus der Routinediagnostik des Instituts für Veterinär-Pathologie. Anhand mittels Pikrosiriusrot gefärb-ter Bioptate wurden Gruppen ohne Alterationen von maximal 5-jährigen Maidenstuten (n = 10) sowie mit ausschließlich graduell variablen Angiosklerosen (jeweils n = 10 mit dezenter, geringgradiger, gering- bis mittelgradiger, mittelgradiger und mittel- bis hochgradiger sowie n = 8 mit hochgradiger Angiosklerose) gebildet. Des Weiteren wurden aus dem Sektionsgut des Instituts Endometriumproben von tragenden Stuten (n = 6), eine weitere Uterusprobe einer trächtig geschlachteten Stute, Bioptate mit gering- bzw. hochgradiger Endometrose in Kombi-nation mit gering- bzw. hochgradiger Angiosklerose (jeweils n = 6) und Bioptate, die an defi-nierten Zyklustagen (Östrus, früher bzw. später Diöstrus) entnommen wurden (jeweils n = 2) entsprechend graduiert. Alle Proben wurden nach erfolgreicher methodischer Etablierung der Antikörper gegen hypo-xia-inducible factor 1α (HIF-1α), Glucosetransporter 1 (GLUT1), vascular endothelial growth factor A (VEGF A) und vascular endothelial growth factor receptor 2 (VEGF-R2) hinsichtlich der Expression dieser Hypoxiemarker immunhistologisch untersucht. Für unterschiedliche Zellpopulationen (luminales Epithel und Zellen der Drüsenausführungsgänge, oberflächliche, mittlere und basale glanduläre Epithelzellen, Stromazellen) und die arteriellen und venösen Blutgefäße (jeweils getrennt nach Intima, Media und Adventitia) wurde markerweise der Im-munreaktive Score (IRS) aus jeweils 10 nebeneinander liegenden Gesichtsfeldern bei 400-facher Vergrößerung (Zellpopulationen) bzw. jeweils 5 Arterien, Arteriolen, Venen und Venulen bestimmt. Die statistische Untersuchung erfolgte mit dem Statistikprogramm SPSS 22 (SPSS Software-GmbH, München). Die Datenvisualisierung wurde mit GraphPad Prism 8 (Graphpad Software Inc., San Diego, Kalifornien, USA) durchgeführt. Ergebnisse: Eine Expression der Hypoxiemarker lässt sich in unterschiedlichen Zellpopulationen darstel-len. HIF-1α ist in nahezu allen Proben im luminalen Epithel, in den Drüsenepithelzellen und in Intima und Media von vor allem arteriellen Gefäßen nachweisbar. Ein nicht signifikanter Trend zu einem höheren IRS zeigt sich erst ab mittel- bis hochgradigen Angiosklerosen in den Drüsenepithelzellen. Demgegenüber lässt sich eine verminderte Expression in der Media von arteriellen Gefäßen erkennen, die für vier Angiosklerose-Gruppen auch statistisch signifikant ist. GLUT1 kann vor allem im Bereich des luminalen Epithels und der Zellen der Drüsenaus-führungsgänge sowie vereinzelt auch in Drüsenepithelzellen nachgewiesen werden. Die ins-gesamt graduell variable Expression sinkt tendenziell mit steigendem Angiosklerosegrad, al-lerdings nicht statistisch signifikant. VEGF A wird von nahezu allen untersuchten Zellpopulati-onen sowie Blutgefäßen und in nahezu allen Proben relativ konstant hoch exprimiert. Zu einer vermehrten Expression kommt es ab Vorliegen einer mittelgradigen Angiosklerose vor allem in den glandulären Epithelzellen, welche bei hochgradiger Angiosklerose auch als statistisch signifikant anzusehen ist. Eine VEGF-R2-Expression lässt sich ebenfalls vorrangig im glan-dulären und luminalen Epithel erkennen, wenngleich sie sich überwiegend geringgradig dar-stellt. Deutliche Unterschiede lassen sich hier in keiner untersuchten Zellpopulation erkennen. Im Zusammenhang mit einer Trächtigkeit zeigen sich Unterschiede in der Expression bei dreien der vier Marker im Bereich des luminalen Epithels und der Zellen der Drüsenausfüh-rungsgänge, also der Schicht, die an der Bildung der feto-maternalen Verbindung beteiligt ist. Im Vergleich zwischen normalen und endometrotischen Drüsen zeigen sich für alle Marker Unterschiede im Expressionsverhalten, die allerdings nicht statistisch signifikant sowie scheinbar unabhängig vom Angiosklerosegrad sind. Eine deutliche Zyklusabhängigkeit konnte nicht nachgewiesen werden. Schlussfolgerungen: Mittels der durchgeführten Untersuchungen wird deutlich, dass insbesondere schwere Angi-osklerosen für immunhistologisch darstellbare hypoxische Zustände sorgen. Ferner zeigen die eigenen Untersuchungen, dass sich die endometrialen Zellpopulationen hinsichtlich der Ex-pression der untersuchten Marker unterscheiden. Dabei wird außerdem deutlich, dass es nicht zwangsläufig zu dem erwarteten Anstieg der Expression der Hypoxiemarker kommen muss. Aus diesem Grund sollte zur Beurteilung des Vorliegens einer Hypoxie eine Untersu-chung der Expression mehrerer derartiger Marker erfolgen. Ein gänzlicher Ausschluss von anderen Einflussfaktoren als Hypoxie auf die Expression der untersuchten Marker kann im verwendeten Studienaufbau nicht erfolgen. Zukünftige Untersuchungen sollten zum einen einen größeren Probenumfang (insbesondere bei der Untersuchung anderer Faktoren als Angiosklerose) aufweisen sowie zum anderen weitere Hypoxiemarker umfassen. Die unter-suchten Marker spielen wahrscheinlich eine Rolle bei besonderen physiologischen (z. B. Trächtigkeit) als auch pathologischen Prozessen (z. B. Endometrose) im equinen Endometri-um und stellen somit interessante pharmakologische Targets zur positiven Beeinflussung der Reproduktionsleistung oder für die Therapie der equinen Endometrose dar. / Introduction: Degenerative alterations of the blood vessels, especially angiosclerosis, are a common finding in equine endometrial biopsies. They are the cause of an insufficient endo-metrial blood supply and therefore result in fertility problems. Objectives: The subject of this thesis was the examination of equine endometrial specimens with variable degrees of angiosclerosis. The hypothesis is that degenerative changes of the vessel wall are the cause of a hypoxic environment. The presence of a potential lack of oxygen as a result of hypoperfusion because of degenerative changes in the blood vessels was assessed via im-munohistochemistry by examining the expression of so-called markers of hypoxia. In addi-tion, the possible relationship to other factors such as the stage of the estrous cycle, pregnan-cy, age or endometrosis was considered. Animals, material and methods: This study is based on equine endometrial biopsies submitted to the diagnostic service of the Institute of Veterinary Pathology. By the means of picrosirius red stain, biopsy groups without any alterations of maiden mares with a maximum age of 5 years (n = 10) as well as biopsies with solely gradually variable angiosclerosis (n = 10 with minimal, mild, mild to moderate, moderate and moderate to severe, as well as n = 8 with severe angiosclerosis, respecively) have been established. In addition, specimens of pregnant mares from necropsied (n = 6) and slaughtered (n = 1) horses, biopsies with mild and severe endometrosis in combination with mild and severe angiosclerosis (n = 6, respectively) and biopsies taken on certain days of the estrous cycle (estrous as well as early and late diestrous, n = 2, respectively) have been graduated likewise. After their successful methodical establishment, all specimens have been examined im-munohistochemically via antibodies against hypoxia-inducible factor 1α (HIF-1α), glucose transporter 1 (GLUT1), vascular endothelial growth factor A (VEGF A) and vascular endothe-lial growth factor receptor 2 (VEGF-R2) in regard to the expression of those markers for hy-poxia. The immunoreactive score (IRS) for each marker has been determined by examining 10 adjacent high-power fields (400-fold magnification) for the different endometrial cell popu-lations (luminal epithelium and cells of glandular ducts, superficial, mid and basal glandular epithelial cells, stromal cells), and 5 arteries, arterioles, veins, and venules, respectively, sepa-rated by intima, media and adventitia. The statistical analysis has been performed via data analysis software SPSS 22 (SPSS Software-GmbH, Munich). The visualisation of data has been done with GraphPad Prism 8 (Graphpad Software Inc., San Diego, California, USA). Results: Expression of the markers of hypoxia was demonstrated in different cell populations. HIF-1α could be detected in almost every specimen in the luminal and glandular epithelia as well as in the intima and media of blood vessels. A non significant trend towards increased IRS was observed in biopsies with at least moderate to severe angiosclerosis in the endometrial glands. In contrast, a diminished expression was identified in the media of arterial vessels, which was significant in four of the angiosclerosis groups. GLUT1 was detected in the luminal epithelium and the cells of glandular ducts as well as in some glandular epithelial cells. In total the ex-pression was variable, with a trend towards lower levels in cases with higher degrees of angi-osclerosis. VEGF A was constantly expressed on relatively high levels by all of the examined cell populations and blood vessels in almost all examined biopsies. There was a trend towards increased expression in cases with moderate angiosclerosis predominantly in the glandular epithelia, reaching statistical significance in endometrial biopsies which are severely altered by angiosclerosis. An expression of VEGF-R2 could be seen in glandular and luminal epitheli-al cells. Nevertheless, no distinct differences were evident. In endometrial specimens of pregnant mares, expressional differences could be identified for three out of the four examined markers, especially in the luminal epithelium and the cells of glandular ducts, which are involved in the development of the feto-maternal connection. The comparison of normal with endometrotic glands revealed a complex expression pattern of all four examined markers which seemed to be independent of the degree of angiosclerosis. A distinct difference in dependence of the phase of the estrous cycle could not be detected. Conclusions: The current study demonstrated that severe angiosclerosis is the cause of an immunohisto-chemically detectable hypoxic condition. Furthermore, this study showed systematic differ-ences in the expression of the examined markers for the different endometrial cell popula-tions. Notably, the employed markers of hypoxia did not always show the expected increase in parallel with increasing grades of angiosclerosis. For that reason, the expression of multiple markers of hypoxia should be assessed to demonstrate a lack of oxygen in tissue samples using immunohistochemistry. The used study design did not allow the complete exclusion of other factors influencing the expression of the examined markers. Therefore, future studies should contain a larger pool of specimens on the one hand (especially while examining other factors than angiosclerosis) and employ a panel of markers of hypoxia. The examined mark-ers seem to play an important role during physiological (e. g. pregnancy) as well as pathologi-cal processes (e. g. endometrosis) and by that might be rewarding pharmacological targets to positively influence reproduction or to possibly treat equine endometrosis.

No description available.

Positionnée en aval des voies PI3K/AKT et RAS/MAPK, la protéine kinase mTOR joue un rôle déterminant dans le développement et la progression tumorale des cancers colorectaux où elle est fortement surexprimée. Par ailleurs, les cancers colorectaux comme toutes les tumeurs solides, ont un microenvironnement hypoxique. L’adaptation des cellules tumorales à l’hypoxie est notamment régulée par la voie PI3K/AKT/mTOR ainsi que par les facteurs de transcription HIFs dont l’expression protéique et l’activité transcriptionnelle est en partie régulée par mTOR. Dans cette étude, nous avons montré que l’inhibition verticale et complète de l’axe PI3K/AKT/mTOR/HIF-1α par l’utilisation combinée d’irinotecan à faible dose et d’inhibiteurs catalytiques de mTOR inhibe significativement la prolifération cellulaire de lignées coliques humaines, la croissance tumorale et le développement de métastases de xénogreffes de tumeurs coliques dérivées de patients.En parallèle, une étude de cohorte de tumeurs coliques humaines de stade III par Tissue Micro Array montre que les facteurs HIFs sont fortement exprimés dans l’épithélium et le stroma de cancers du côlon de stade III, qu’une faible expression nucléaire de HIF-1α dans les cellules épithéliales confère une mauvaise survie aux patients et qu’elle a une valeur prédictive de moins bonne réponse au traitement 5-FU. / Downstream of the PI3K/AKT and RAS/MAPK pathways, mTOR protein kinase plays a decisive role in the development and tumor progression of colorectal cancers. Furthermore, the microenvironment of colorectal cancers is hypoxic. The adaptation of the tumor cells to hypoxia is regulated by the PI3K/AKT /mTOR pathway as well as by the HIFs transcription factors whose protein expression and transcriptional activity is partially regulated by mTOR. In this study, we showed that the vertical and complete inhibition of the PI3K / AKT / mTOR /HIF-1α axis by the combined use of low-dose irinotecan and mTOR catalytic inhibitors significantly inhibits human colon cancer cell proliferation, as well as the growth and metastatic development of xenografted human colon tumors. In parallel, a Tissue Micro Array study on a cohort of stage III human colic tumors shows that the HIFs are strongly expressed in the epithelium and stroma of the tumors and a low nuclear expression of HIF-1α in epithelial cells provides with poor survival to patients and has a predictive value of worse response to 5-FU treatment.

Οι όγκοι εγκεφάλου αποτελούν μια ομάδα όγκων με ιδιαίτερα χαρακτηριστικά. Η ογκογένεση έχει συσχετισθεί σε αρκετούς όγκους, ανάμεσά τους και ορισμένοι όγκοι εγκεφάλου, με την πρωτείνη θερμικού σοκ 90 (Hsp90). Σε πρόσφατες μελέτες, έχει αποδειχθεί η η συμμετοχή της Hsp90 στην αποδόμηση της ογκοκατασταλτικής πρωτείνης pVHL, η οποία είναι απαραίτητητη για την αποδόμηση του μεταγραφικού παράγοντα που ενεργοποιείται στην υποξία (HIF-1α). Επιπλέον, έχει βρεθεί πως οι ανταγωνιστές της Hsp90 μειώνουν τα επίπεδα έκφρασης του VEGFR-3. Στόχος της παρούσας μελέτης ήταν η εκτίμηση των επιπέδων έκφρασης των μορίων Hsp90, pVHL, HIF-1α και VEGFR-3 στους όγκους εγκεφάλου και οι πιθανές συσχετίσεις μεταξύ τους. Εξετάσθηκαν συνολικά 89 óγκοι εγκεφάλου με την ανοσοϊστοχημική μέθοδο. Στους αστροκυτταρικούς όγκους, η Ηsp90 φαίνεται πως οδηγεί στη σταθεροποίηση του HIF-1α μέσω της σύνδεσής της με τη pVHL. Στα μυελοβλαστώματα από την άλλη, ο HIF-1α ρυθμίζεται από τη Hsp90 με τρόπο ανεξάρτητο από τη pVHL. Βρέθηκε συσχέτιση της έκφρασης του VEGFR-3 με τη Hsp90 αλλά και τον HIF-1α σε ομάδα όγκων του εγκεφάλου, η βιολογική συμπεριφορά των οποίων θα πρέπει να διερευνηθεί. / Brain tumors constitute a special group of tumors. In many tumors, including brain tumors, tumorigenesis has been associated with heat shock protein 90 (Hsp90). ). Recent studies have demonstrated that Hsp90 is essential for the degradation of tumor suppressor protein, pVHL, which is essential for the degradation of Hypoxia Induced Factor 1α (HIF-1α). In addition,it has been proved that Hsp90 antagonists, reduce the expression VEGFR-3. the aim of the current study was to estimate the levels of expression of Hsp90, pVHL, HIF-1α and VEGFR-3 in brain tumors and the possible correlations among them.89 human brain tumors were studied immunohistochemically. In astrocytic tumors, Hsp90 seems to stabilize HIF-1α, through binding to pVHL. On the other hand, in medulloblastomas, HIF-1α seems to be regulated by Hsp90, in a way that seems to be independent from pVHL. We found a correlation between the expression of VEGFR-3 and Hsp90 and HIF-1α in a group of brain tumors, the biological behavior of which must be studied.

In our studies we found that stabilized expression of HIF-1α in heart led to better recovery of function and less tissue death after 30 minutes of global ischemia, via mechanisms that preserve the mitochondrial polarization. Our group previously showed that HIF-1α conferred ischemic tolerance by allowing cardiomyocytes to use fumarate as an alternative terminal electron acceptor to sustain anaerobic mitochondrial polarization. The source of fumarate was identified as the purine nucleotide cycle (PNC). Here we discovered that HIF-1α upregulates AMP deaminase 2 (AMPD2), the entry point to the PNC. The combination of glycolysis and the PNC may protect the heart's nucleotide resources. We subsequently examined the effects that HIF-1α exerts on nucleotide metabolism in the ischemic heart. We found that HIF-1α expression reduces adenosine accumulation in the ischemic heart. As ATP is depleted during ischemia, AMP accumulates. Our results suggest that AMP metabolism is shunted towards AMPD2 rather than the adenosine producing 5'-nucleotidase pathway. Subsequently, we treated hearts with the PNC inhibitor hadacidin followed by 30 minutes of global ischemia. Inclusion of hadacidin reduced ATP and adenylate energy charge in the hearts. These findings allow us to propose that activity of the PNC prevents the F0F1 ATP synthase from consuming glycolytic ATP in order to maintain mitochondrial polarization during ischemia. Thus, the PNC provides ATP sparing effects and preserves the energy charge in the ischemic heart. The fact that ATP and adenylate energy charge is better preserved during the initial 20 minutes of ischemia in HIF-1α expressing hearts is supportive of our observation that HIF-1α upregulates the PNC. HIF-1α also upregulates adenosine deaminase, which degrades adenosine. The limitation of adenosine accumulation may help HIF-1α expressing hearts avoid toxicity due to chronic adenosine exposure. Finally, we found that HIF-1α induces the expression of the nucleotide salvage enzyme hypoxanthine phosphoribosyl transferase (HPRT). Upon reperfusion HPRT serves to reincorporate the nucleotide degradation product, hypoxanthine, into the adenylate pool and may prevent the production of reactive oxygen species. Collectively, HIF-1α robustly protects the heart from ischemic stress and it upregulates several pathways whose cardioprotective role may extend beyond the remodeling of nucleotide metabolism.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Thymic stromal lymphopoietin (TSLP) is a functionally pleotropic cytokine important in immune regulation, and TSLP dysregulation is associated with numerous diseases. TSLP is produced by many cell types, but has predominantly been characterized as a secreted factor from epithelial cells which activates dendritic cells (DC) that subsequently prime T helper (TH) 2 immunity. However, DC themselves make significant amounts of TSLP in response to microbial products, but the functional role of DC-derived TSLP remains unclear. We show that TSLPR signaling negatively regulates IL-1β production during dectin-1 stimulation of human DC. This regulatory mechanism functions by dampening Syk phosphorylation and is mediated via NADPH oxidase-derived ROS, HIF-1α and pro-IL-1β expression. Considering the profound effect TSLPR signaling has on the metabolic status and the secretome of dectin-1 stimulated DC, these data suggest that autocrine TSLPR signaling could have a fundamental role in modulating immunological effector responses at sites removed from epithelial cell production of TSLP.

Yes / The chemokine receptor CCR7 is expressed on lymphocytes and dendritic cells and is responsible for trafficking of these cells in and out of secondary lymphoid organs. It has recently been shown that CCR7 expression is elevated in a number of cancers, including head and neck cancers, and that its expression correlates to lymph node (LN) metastasis. However, little is known about the factors that can induce CCR7 expression in head and neck cancers. We compared the protein expression and functional responses of CCR7 under normoxia and hypoxia in head and neck cancer cell lines OSC-19, FaDu, SCC-4, A-253 and Detroit-562 cultured as monolayers, spheroids, and grown in vivo as xenografts in balb/c mice. In addition, we analysed the correlation between hypoxia marker HIF-1α and CCR7 expression in a tissue microarray comprising 80 clinical samples with various stages and grades of malignant tumour and normal tissue. Under hypoxia, the expression of CCR7 is elevated in both in vitro and in vivo models. Furthermore, in malignant tissue, a correlation is observed between hypoxia marker HIF-1α and CCR7 across all clinical stages. This correlation is also strong in early histological grade of tumours. Hypoxia plays a role in the regulation of the expression of CCR7 and it may contribute to the development of a metastatic phenotype in head and neck cancers through this axis.

L’hypoxie tumorale par l’intermédiaire d’une de ses cibles HIF-1α, est associée à la transition épithélio-mésenchymateuse (TEM) dans de nombreuses tumeurs solides. La TEM a été associée aux résistances à la chimiothérapie et aux métastases dans de nombreux cancers. Dans ce travail, nous avons montré que l’hypoxie tumorale définit un pronostic péjoratif après chirurgie d’un cancer bronchique non à petites cellules (CBNPC). Nous avons également montré sur des lignées cellulaires de CBNPC présentant des mutations activatrices de l’EGFR, que l’hypoxie via HIF-1α, induit la TEM, avec activation de différents facteurs de transcription dépendant du statut mutationnel des lignées : induction de SNAIL-1/SNAIL-2 dans la lignée H1650 ayant une deletion de l’exon 19 et induction de SNAIL-1/ZEB-1 dans la lignée H1975 ayant la mutation L858R de l’exon 21 et T790M de l’exon 20. En considérant l’ensemble de ces données, il apparaît que HIF-1α peut être une nouvelle cible thérapeutique. / Tumoral hypoxia, and his target HIF-1α, are linked to the epithelial to mesenchymal transition (EMT) in various solid tumors. EMT has been linked to chemotherapy resistance and metastases in many cancers. In this work, we have shown that tumoral hypoxia may help to define a worst prognosis in case of hypoxia after non-small cell lung cancer surgery (NSCLC). We have also shown that on NSCLC cell lines harboring activating EGFR mutations, hypoxia trough expression of HIF-1α, was able to induce EMT, with activation of different transcription factors according to cell mutational status: induction of SNAIL-1/SNAIL-2 in H1650 cell line harboring exon 19 deletion, induction of SNAIL-1/ZEB-1 in H1975 cell line harboring both exon 21 L858R and exon 20 T790M mutations. Considering all these data, it appears that HIF-1α may be considered a a new therapeutic target.