• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 78
  • 22
  • 18
  • 8
  • 5
  • 4
  • 4
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 175
  • 175
  • 175
  • 147
  • 49
  • 27
  • 27
  • 23
  • 19
  • 17
  • 17
  • 17
  • 17
  • 16
  • 16
  • 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.
141

Patohistološka procena tumorske regresije kod nemikrocelularnih karcinoma pluća posle neoadjuvantne terapije / Histopathologic assessment of tumor regression in non-small cell lung cancer after neoadjuvant therapy

Samardžija Golub 14 September 2016 (has links)
<p>Karcinomi pluća su najče&scaron;ći uzrok oboljevanja i umiranja od malignih tumora u Svetu. Neodjuvantna terapija kod bolesnika sa lokalno uznapredovalim (IIIA-IIIB) karcinomom pluća i zahvaćenim N2 limfnim čvorovima jedan je od modusa multimodalnog lečenja bolesnika sa nemikrocelularnim karcinomima pluća (NSCLC) u cilju pobolj&scaron;anja ishoda njihovog lečenja. Ovakav pristup podrazumeva prevođenje bolesnika iz vi&scaron;eg u niži stadijum bolesti - &bdquo;downstaging&rdquo;. Do danas nije utvrđena povezanost između pojedinih obrazaca tumorskog odgovora i vrste terapije. S obzirom na značaj kompletnog patolo&scaron;kog odgovora i tumorske regresije u prognozi ishoda lečenja, iznalaženje ove povezanosti je od značaja za dizajniranje budućih neoadjuvantnih trajala. Prilikom utvrđivnja histolo&scaron;ke slike tumorske regresije veoma je važno i merenje areje rezidualnog tumora (ART). Kako je veličina tumora jedan od prognostičkih faktora za bolesnike sa NSCLC koji nisu primali neoadjuvantnu terapiju tako je i merenje ART, za razliku od makroskopske veličine tumora, jedan od prognostičkih faktora za bolesnike sa NSCLC koji su primali neoadjuvantnu terapiju. Krajnji cilj neoadjuvantne terapije trebalo bi da bude resektabilnost i &bdquo;downstaging&rdquo; koji bi mogao da obezbedi u specifičnim kliničkim situacijama i sveukupni onkolo&scaron;ki benefit. Osnovni ciljevi ove doktorske disertacije su bili: da se objektivizira procena veličine ART u tumorskom tkivu pluća i limfnih čvorova; da se proceni povezanost povr&scaron;ine ART sa veličinom tumora na postoperativnom hirur&scaron;kom materijalu posle neoadjuvantne terapije; da se analizira i proceni povezanost histomorfolo&scaron;kih parametara kod tumorske regresije indukovane neoadjuvantnom terapijom i spontane tumorske regresije u tumorima pluća i limfnih čvorova na&nbsp; postoperativnom hirur&scaron;kom materijalu i u zavisnosti od histolo&scaron;kog tipa karcinoma; da se proceni povezanost kliničkog odgovora na neoadjuvantnu terapiju prema kriterijumima Svetske Zdravstvene Organizacije i histolo&scaron;kih parametara u tumorima pluća i limfnim čvorovima na postoperativnom hirur&scaron;kom materijalu nakon neoadjuvantne terapije; da se proceni povezanost patolo&scaron;kog ypTN sa kliničkim ycTN stadijumom bolesti i stepena tumorske regresije indukovane neoadjuvantnom terapijom i patolo&scaron;kog ypTN i da se proceni povezanosti između kliničke i patolo&scaron;ke zahvaćenosti N2 limfnih čvorova posle neoadjuvantne terapije. Merenje ukupne veličine očuvanih ART je najznačajniji objektivni parametar u proceni stepena tumorske regresije. Veličina rezidualnog tumora nije u korelaciji sa veličinom tumora posle neoadjuvantne terapije. Postoji signifikantna razlika u patohistolo&scaron;koj slici tumorske regresije indukovane neoadjuvantnom terapijom i spontane tumorske regresije. Ne postoji signifikantna razlika između histolo&scaron;kog tipa tumora i histolo&scaron;ke slike tumorske regresije. Ne postoji signifikantna povezanost između kliničkog odgovora i stepena tumorske regresije nakon neoadjuvantne terapije. Ne postoji korelacija između kliničkog i patolo&scaron;kog stadijuma bolesti posle neoadjuvantne terapije. Ne postoji korelacija između stepena tumorske regresije indukovane neoadjuvantnom terapijom i ypTN stadijuma bolesti. Ne postoji korelacija između kliničke i patolo&scaron;ke zahvaćenosti N2 limfnih čvorova posle neoadjuvantne terapije. Stepen regresije tumora i merenje ART posle neoadjuvantne terapije određen histopatolo&scaron;kom analizom reseciranog tumora je najobjektivniji kriterijum za procenu hemioterapijskog odgovora i predviđanja ishoda lečenja pacijenata.</p> / <p>Lung cancers are the most common cause of morbidity and mortality from malignant tumors in the World. The neodjuvant therapy in patients with locally advanced (IIIA-IIIB) lung cancer and affected N2 lymph nodes is one of the modes of multimodal treatment of patients with non-small cell lung cancer (NSCLC) in order to improve the outcome of their treatment. This involves converting patients from a higher to a lower stage of the disease - &quot;downstaging&quot;. There has been no significant connection between some forms of tumor response and types of therapy. Given the importance of complete pathological responses and tumor regression in the prediction of treatment outcomes, finding this relationship is of importance for the design of future neoadjuvant trails. In determining the histological tumor regression is very important measurement of area of residual tumor (ART). As the size of the tumor is one of the prognostic factors in patients with NSCLC who did not receive neoadjuvant therapy so the measurement of ART, as opposed to the macroscopic size of the tumor, one of the prognostic factors in patients with NSCLC, who had received neoadjuvant therapy. The ultimate goal of neoadjuvant therapy should be resectability and &quot;downstaging&quot; that could provide overall oncology benefit in specific clinical situations. The main objectives of this thesis were: to objectively estimate the size of ART in tumor tissue of lung and lymph nodes; to estimate the relation between the surface of ART with the size of the tumor on postoperative surgical material after neoadjuvant therapy; to analyze and estimate the relation between histomorphological parameters in tumor regression induced by neoadjuvant therapy and spontaneous tumor regression in tumors of the lung and lymph nodes in the postoperative surgical material and depending on the histological type of cancer; to estimate the relation between clinical response to neoadjuvant therapy according to criteria of the World Health Organization and histological parameters in lung tumors and lymph nodes in the postoperative surgical material after neoadjuvant therapy; to estimate the correlation of the pathological ypTN with clinical ycTN stage of the disease and the degree of tumor&nbsp; regression induced by neoadjuvant therapy and pathological ypTN and estimation of the relation between clinical and pathological involvement of N2 lymph nodes after neoadjuvant therapy. Measurement of the total size of the preserved ART is the most important objective parameter in the assessment of the grade of tumor regression. Size of residual tumor did not correlate with the size of the tumor after neoadjuvant therapy. There was a significant difference in the histological picture of tumor regression induced by neoadjuvant therapy and spontaneous tumor regression. There was no significant difference between the histologic type of tumor and histological tumor regression. There is no significant correlation between clinical response and the grade of tumor regression after neoadjuvant therapy. There is no correlation between clinical and pathological staging of the disease after neoadjuvant therapy. There is no correlation between the grade of tumor regression induced by neoadjuvant therapy and ypTN stage of the disease. There is no correlation between the clinical and the pathological involvement of the N2 lymph nodes to neoadjuvant therapy. The grade of tumor regression and measurement ART after neoadjuvant therapy determined by histopathological analysis of the resected tumor is the most objective criterion for evaluation of chemotherapeutic response and prediction of treatment outcome in patients.</p>
142

Traitement du cancer pulmonaire non à petites cellules par radiothérapie stéréotaxique d’ablation

Mathieu, Dominique 03 1900 (has links)
Les néoplasies pulmonaires demeurent la première cause de décès par cancer au Québec représentant près de 6000 décès par année. Au cours des dernières années, la radiothérapie stéréotaxique d’ablation (SABR) s’est imposée comme un traitement alternatif à la résection anatomique pour les patients inopérables atteints d’un cancer pulmonaire non à petites cellules de stade précoce. Il s’agit d’une modalité de traitement qui permet d’administrer des doses élevées, typiquement 30-60 Gy en 1-8 fractions, dans le but de cibler précisément le volume de traitement tout en épargnant les tissus sains. Le Centre Hospitalier de l’Université de Montréal s’est muni en 2009 d’un appareil de SABR de fine pointe, le CyberKnife™ (CK), un accélérateur linéaire produisant un faisceau de photons de 6 MV dirigé par un bras robotisé, permettant d’administrer des traitements non-coplanaires avec une précision infra-millimétrique. Ce mémoire est dédié à la caractérisation de certains enjeux cliniques et physiques associés au traitement par CK. Il s’articule autour de deux articles scientifiques revus par les pairs. D’une part, une étude prospective clinique présentant les avantages de la SABR pulmonaire, une technique qui offre un excellent contrôle tumoral à long terme et aide au maintien de la qualité de vie et de la fonction pulmonaire. D’autre part, une étude de physique médicale illustrant les limites de l’acquisition d’images tomodensitométriques en auto-rétention respiratoire lors de la planification de traitement par CK. / Lung neoplasia remains the leading cause of cancer death accounting for nearly 6,000 deaths per year in Quebec. In recent years, stereotactic ablative radiotherapy (SABR) has emerged as an alternative treatment to anatomical resection for inoperable patients suffering from early stage non-small cell lung cancer. This technique can deliver highly focused doses such as 30-60 Gy in 1-8 fractions in order to target precisely the treatment volume while sparing healthy tissue. In 2009, the Centre Hospitalier de l’Université de Montréal acquired a robotic SABR apparatus, the CyberKnife™ (CK), a linear accelerator mounted on a moving arm producing non-coplanar photon beams of 6 MV with millimetric precision. This thesis presents two scientific peer reviewed articles adressing some clinical and physical challenges with CK. On one hand, a clinical prospective study reporting the advantages of lung SABR, a technic that offers excellent long-term tumor control and helps maintain the quality of life and lung function. On the other hand, a medical physics study exposing the limits of computed tomography scan acquisition in breath-holding for CK treatment planning.
143

Exprese markerů imunogenní buněčné smrti na buňkách karcinomu plic / Expression of immunogenic cell death markers on lung cancer cells

Kobosilová, Linda January 2014 (has links)
Immunogenic cell death (ICD) is characterized by presence of specific molecules including surface exposed calreticulin (CRT) and the heat shock proteins HSP70 and HSP90. Release of ATP and high- mobility group box protein 1 (HMGB1) belongs to other typical characteristics. For induction of ICD in lung cancer cells high-hydrostatic pressure (HHP) was used. Treatment by HHP induces expression of immunogenic markers CRT, HSP70 and HSP90 on the cell surface. HHP also induces secretion of ATP to the extracellular milieu. Dendritic cells (DC) pulsed with HHP-treated tumor cells showed fenotypic maturation characterized by upregulation of maturation molecule CD83, costimulation molecules CD80 and CD86, chemokine receptor CCR7 and MHC class II molecule HLA-DR. Pulsed DCs have also higher rate of phagocytosis of HHP-treated tumor cells and they induce lower numbers of regulatory T cells compared to immature DCs. Moreover, activation of caspases (-8, -9, -3) and other proteins (phosphorylation of eIF2α) which are crucial in ER-stress mediated apoptotic pathway, was observed after HHP treatment. Using wide range of methods it was confirmed that HHP treatment is able to induce ICD in lung cancer cell lines, fenotypic and functional characteristics were described and the decreased induction of regulatory T-lymphocytes...
144

Role of microRNAs in non-small cell lung carcinoma : effect of heme oxygenase-1 / Rôle des microARNs dans le carcinome pulmonaire non à petites cellules : effet de l’hème oxygénase-1

Skrzypek, Klaudia 08 January 2013 (has links)
L’hème oxygénase-1 (HO-1), enzyme antioxydante, est capable de prévenir l’initiation tumorale tandis qu’elle promeut la progression de certaines tumeurs et l’angiogenèse. Ce travail a recherché si HO-1 peut moduler les microARNs et régule le développmemnt du carcinome pulmonaire humain non à petites cellules (NSCLC). La surexpression stable de HO-1 dans les cellules du NSCLC NCI-H292 accroit la production globale des miARNs et diminue significativement l’expression des oncomirs et angiomirs, tandis qu’elle augmente les miARNs suppresseurs de tumeurs. Le plus amplement diminué est le miR-378. Dans les cellules surexprimant HO-1 la p53 est aussi augmentée, Ang-1 et MUC5AC diminuées, prolifération migration et potentiel angiogéniques réduits. Les effets de HO-1 sur la prolifération tumorale, la migration et et l’expression de miR-378 sont modulées par CO. Au contraire, la surexpression stable de miR-378 décroit celle de HO-1 et de p53 tandis qu’elle accroît celle de MUC5AC, VEGF, IL-8 et Ang-1 et en conséquence accroit la prolifération, migration la stimulation des cellules endothéliales. L’ajout de HO-1 à des cellules surexprimant miR-378 réverse l’effet de miR-378 sur la prolifération et la migration des cellules cancéreuses. In vivo, les tumeurs surexprimant HO-1 sont de taille réduite, moins vascularisées et oxygénées et moins métastatiques tandis que la surexpression de miR-378 produit les effets inverses. Conformément, chez les patients NSCLC, l’expression de HO-1est réduite dans les métastases lymphatiques par rapport à la tumeur primaire tandis que miR-378 n’est pas modifié de manière significative. En conclusion, les résultats in vitro et in vivo indiquent que l’action coordonnée entre HO-1 et miR-378 module de manière significative la progression et l’angiogenèse du carcinome humain pulmonaire non à petites cellules. / Heme oxygenase-1 (HO-1), an antioxidant enzyme can prevent tumor initiation while it has been demonstrated to promote various tumors progression and angiogenesis. Here it was investigated whether HO-1 can modulate microRNAs and regulate human non-small cell lung cancer (NSCLC) development. Stable HO-1 overexpression in NSCLC NCI-H292 cells enhanced global production of miRNAs and significantly diminished expression of oncomirs and angiomirs, whereas upregulated tumor suppressive miRNAs. The most potently downregulated was miR-378. HO-1 overexpressing cells displayed also upregulated p53, downregulated Ang-1 and MUC5AC, reduced proliferation, migration and diminished angiogenic potential. CO was a mediator of HO-1 effects on tumor cells proliferation, migration and miR-378 expression. In contrast, stable miR-378 overexpression decreased HO-1 and p53 while enhanced expression of MUC5AC, VEGF, IL-8 and Ang-1 and consequently increased proliferation, migration and stimulation of endothelial cells. Adenoviral delivery of HO-1 to miR-378 overexpressing cells reversed miR-378 effect on proliferation and migration of cancer cells. In vivo, HO-1 overexpressing tumors were smaller, less vascularized and oxygenated and less metastatic, whereas miR-378 overexpression exerted the opposite effects. Accordingly, in patients with NSCLC, HO-1 expression was lower in metastases to lymph nodes than in primary tumors while miR-378 did not differ significantly. To conclude, in vitro and in vivo data indicate that interplay between HO-1 and miR-378 significantly modulates NSCLC progression and angiogenesis.
145

Les inhibiteurs de PARP dans le traitement des cancers chimio-résistants : étude pré-clinique sur la dépendance à PARP / PARP inhibitors for the treatment of chemoresistant cancers : a preclinical study of PARP addiction

Michels, Judith 12 September 2013 (has links)
Introduction Le cancer bronchique est un problème de santé publique en étant la première cause de décès par cancer dans le monde. Il reste de mauvais pronostic avec une résistance au Cisplatine qui est inéluctable dans l’histoire naturelle de la maladie. Nous nous sommes intéressés à l’association du CDDP aux inhibiteurs de la Poly(ADP-ribose) polymérase. Les inhibiteurs pharmacologiques de PARP sont source d’optimisme en oncologie clinique en monothérapie pour des tumeurs déficientes pour une voie de réparation de l’ADN et en association aux cytotoxiques classiques.Matériel et méthodes Nous avons généré 9 clones résistants au CDDP après culture de la lignée A549 dans des faibles doses de CDDP. Deux inhibiteurs pharmacologiques de PARP, CEP8983 (CEP) et PJ34 (PJ), ainsi que des siRNA spécifiques de PARP1 sont utilisés pour l’inhibition de PARP. L’apoptose est mesurée en cytométrie de flux par l’intermédiaire du potentiel membranaire de la mitochondrie DiOC6(3) et la perméabilisation de la membrane plasmique est évaluée par l’iodide de propidium. Le test de clonogénicité permet d’évaluer la capacité des cellules à échapper à la mort et à former une colonie. L’activité métabolique des cellules est mesurée par la mesure de clivage du sel de tetrazolium WST-1. L’immunofluorescence sur cellules fixées a permis d’étudier les dommages de l’ADN (γH2AX), la voie intrinsèque de l’apoptose (l’activation de la caspase 3 et la libération du cytochrome c) et la recombinaison homologue (BRCA1, RAD51). En Western Blot nous avons mesuré l’expression et l’activité de PARP (PAR) ainsi que l’expression d’acteurs de la réparation par excision de base (BER) (XRCC1 and polymérase β). Nous avons développé une méthode de détection de PAR en immunohistochimie sur des tissus inclus en paraffine. Résultats Nous avons trouvé un effet synergique pour l’association du CDDP aux inhibiteurs de PARP in vitro. De façon inattendue nous avons observé que les clones résistants au CDDP développent une addiction à PARP et sont spécifiquement tués par l’inhibition de PARP contrairement à la lignée parentale. Ces clones exhibent une hyperexpression et une hyperactivité de PARP. La réponse aux inhibiteurs de PARP corrèle plus précisément avec l’activation plutôt qu’avec l’expression de PARP, pointant que PAR est un biomarqueur plus précis que PARP. Nous avons observé que l’hyperactivation de PARP accompagne une résistance induite au CDDP et prédispose à une sensibilité aux inhibiteurs de PARP dans d’autres lignées de cancer bronchique (H460 et H1650), de mésothéliome (P31), de cancer de l’ovaire (TOV112D) et de col (HeLa). Dans des expériences in vivo nous avons noté que dans les xénogreffes obtenues à partir de clones résistants au CDDP, l’expression de PAR est stablement retrouvée en immunohistochimie. Ces tumeurs répondaient à l’inhibition de PARP par le PJ en diminuant l’expression de PAR. Les clones résistants au CDDP sensibilisés aux I PARP ont une recombinaison homologue conservée, cependant ont un déficit dans les étapes terminales du BER.Conclusion Nous avons identifié un effet synergique pour l’association des inhibiteurs de PARP au CDDP de des lignées de cancer bronchique. Nous avons observé une dépendance à PARP dans des lignées de cancer bronchique résistantes au CDDP et déficientes pour l’élongation du BER. Nous postulant que PAR est un biomarqueur spécifique de la réponse aux inhibiteurs de PARP. / Introduction Driven by the facts that non small cell lung cancer (NSCLC) is the leading cause of cancer-related morbidity and mortality worldwide and that NSCLC patients often develop resistance against Cisplatin (CDDP)-based therapies, we addressed the question of the combination therapy of CDDP with poly(ADP-ribose) polymerases (PARP) inhibitors. Inhibitors of PARP have raised great expectations for the treatment of a variety of cancers, either as monotherapeutic agent against DNA repair-deficient tumours or combined to DNA-damaging compounds.Material and methods We generated nine CDDP-resistant clones by prolonged exposure to low dose CDDP of the A549 NSCLC parental cell line. Two distinct PARP inhibitors, CEP8983 (CEP) and PJ34 (PJ) as well as PARP1 knockdown with small interfering RNAs (siRNAs) were used for PARP inhibition. Apoptosis was measured by the simultaneous assessment for the loss of the mitochondrial transmembrane potential (m) and the breakdown of the plasma membrane using the m-sensitive fluorochrome DiOC6(3) and the vital dye propidium iodide, respectively. Moreover clonogenic survival was assessed. In vitro assessments of the enzymatic activity of cells were based on the reduction of the colorless tetrazolium salt. Immunofluorescence microscopy determinations were performed with antibodies specific for DNA damage (γH2AX), intrinsic apoptosis (cleaved Caspase-3 and cytochrome c), and homologous recombination (RAD51 and BRCA1). Immunoblotting was assed for PARP1 expression and activity (PAR) and base excision repair (BER) effectors (XRCC1 and polymerase β). We developed an immunohistochemical staining method that specifically detects PAR on paraffin-embedded cell pellets and tissue sections.Results We found that PARP inhibitors and PARP1 siRNAs synergized with CDDP in the killing of NSCLC cells in vitro. Unexpectedly, CDDP-resistant NSCLC cell clones developed addiction to PARP hyperactivation, thereby becoming susceptible to apoptosis induction by PARP inhibition. We showed that these cisplatin-resistant clones, exhibited high PARP protein levels and increased PARP activity, leading to an increased poly-ADP ribosylation of cellular proteins, as compared to their parental, cisplatin-sensitive counterparts. These cisplatin-resistant cells become susceptible to cell death as induced by PARP inhibition, correlating with the hyperactivity of PARP (elevated PAR levels) more accuratly than with the overexpression of PARP. Suggesting that PAR levels may constitute a more accurate biomarker than PARP to predict the sensitivity of cells to PARP inhibition. We expanded the observation that cisplatin resistance causes PARP upregulation and hyperactivation and subsequent sensitization to PARP inhibition to additional five human cancer cell lines including two NSCLC (H1650 and H460), one mesothelioma (P31), one ovarian (TOV112D) and one cervical cancer (HeLa) cell line. To get further insight into this issue, we generated in vivo experiments. Tumors derived from CDDP-resistant cells were characterized by elevated levels of PAR suggesting that PAR levels are preserved during tumor formation. Those PAR-overexpressing tumors responded to the administration of PJ in vivo with a consistent reduction in PAR immunoreactivity. CDDP resistant clones that are specifically killed by PARP inhibitors assessed efficient homologous recombination repair however deficient BER elongation.Conclusion We showed a beneficial effect for the association therapy of PARP inhibitors with CDDP in several NSCLC cell lines. We have identified an addiction to PARP in CDDP resistant cell lines with deficient BER elongation. We postulate that PAR is a specific predictive biomarker for the response to PARP inhibitors.
146

Cancer bronchique primitif, voies de signalisation intra-cellulaires et modèles précliniques / Lung cancer, intracellular signaling pathways, and preclinical models

Mordant, Pierre 21 December 2012 (has links)
Contexte. Le cancer bronchopulmonaire (CBP) demeure la première cause de mortalité par cancer dans le monde. Malgré l’espoir suscité par le développement des thérapies ciblées, son pronostic demeure sombre, particulièrement dans les cas de CBP à petites cellules (CBP-PC) et de CBP non à petites cellules (CBP-NPC) présentant une activation de l’oncogène KRAS. Matériel et Méthodes. Nous avons mené 3 études successives, visant à (i) radiosensibiliser des modèles de CBP-PC par l’ajout d’un inhibiteur de BCL2, (ii) cibler des modèles de CBP-NPC mutés KRAS par l’association d’un inhibiteur de mTOR et d’un inhibiteur de RAF, et (iii) créer un modèle préclinique orthotopique murin de CBP reproduisant la progression tumorale observée en clinique. Résultats. Dans la première étude, l’inhibiteur de BCL2 oblimersen a présenté un effet radiosensibilisant sur des modèles de CBP-PC, in vitro et in vivo. Dans la seconde étude, l’association de l’inhibiteur de mTOR everolimus et de l’inhibiteur de RAF/VEGFR RAF265 a présenté un effet synergique sur des lignées cellulaires de cancers présentant la double mutation de KRAS et de PIK3CA, in vitro et in vivo. Dans la troisième étude, l’injection orthotopique d’une lignée bioluminescente de CBP-NPC chez des souris nude a permis d’établir des tumeurs intra pulmonaires évoluant vers une extension métastatique ganglionnaire et hématogène, et de détecter la présence de cellules tumorales circulantes. Conclusion. L’association d’un inhibiteur de BCL2 à la radiothérapie est une stratégie intéressante dans le CBP-PC, l’association d’un inhibiteur de mTOR et d’un inhibiteur de RAF/VEGFR est une stratégie intéressante dans le CBP-NPC présentant une double mutation KRAS-PIK3CA, mais ces données doivent être confirmées sur des modèles orthotopiques afin de gagner en pertinence avant d’envisager un transfert en clinique. / Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related mortality worldwide. Activation of phosphatidylinositol-3-kinase (PI3K)-AKT and Kirsten rat sarcoma viral oncogene homologue (KRAS) can induce cellular immortalization, proliferation, and resistance to anticancer therapeutics such as epidermal growth factor receptor inhibitors or chemotherapy. This study assessed the conséquences of inhibiting these two pathways in tumor cells with activation of KRAS, PI3K-AKT, or both. We investigated whether the combination of a novel RAF/vascular endothelial growth factor receptor inhibitor, RAF265, with a mammalian target of rapamycin (mTOR) inhibitor, RAD001 (everolimus), could lead to enhanced antitumoral effects in vitro and in vivo. To address this question, we used cell lines with different status regarding KRAS, PIK3CA, and BRAF mutations, using immunoblotting to evaluate the inhibitors, and MTT and clonogenic assays for effects on cell viability and proliferation. Subcutaneous xenografts were used to assess the activity of the combination in vivo. RAD001 inhibited mTOR downstream signaling in all cell lines, whereas RAF265 inhibited RAF downstream signaling only in BRAF mutant cells. In vitro, addition of RAF265 to RAD001 led to decreased AKT, S6, and Eukaryotic translation initiation factor 4E binding protein 1 phosphorylation in HCT116 cells. In vitro and in vivo, RAD001 addition enhanced the antitumoral effect of RAF265 in HCT116 and H460 cells (both KRAS mut, PIK3CA mut); in contrast, the combination of RAF265 and RAD001 yielded no additional activity in A549 and MDAMB231 cells. The combination of RAF and mTOR inhibitors is effective for enhancing antitumoral effects in cells with deregulation of both RAS-RAF and PI3K, possibly through the cross-inhibition of 4E binding protein 1 and S6 protein. We then focus on animal models. Preclinical models of NSCLC require better clinical relevance to study disease mechanisms and innovative therapeutics. We sought to compare and refine bioluminescent orthotopic mouse models of human localized NSCLC. Athymic nude mice underwent subcutaneous injection (group 1-SC, n = 15, control), percutaneous orthotopic injection (group 2-POI, n = 30), surgical orthotopic implantation of subcutaneously grown tumours (group 3-SOI, n = 25), or transpleural orthotopic injection (group 4-TOI, n = 30) of A549-luciferase cells. Bioluminescent in vivo imaging was then performed weekly. Circulating tumour cells (CTCs) were searched using Cellsearch® system in SC and TOI models Group 2-POI was associated with unexpected direct pleural spreading of the cellular solution in 53% of the cases, forbidding further evaluation of any localized lung tumour. Group 3-SOI was characterized by high perioperative mortality, initially localized lung tumours, and local evolution. Group 4-TOI was associated with low perioperative mortality, initially localized lung tumours, loco regional extension, and distant metastasis. CTCs were detected in 83% of nude mice bearing subcutaneous or orthotopic NSCLC tumours. Transpleural orthotopic injection of A549-luc cells in nude mouse lung induces localized tumour, followed by lymphatic extension and specific mortality, and allowed the first time identification of CTCs in a NSCLC mice model.
147

Estudo da participação do colágeno V no câncer de pulmão, especificamente no carcinoma não de pequenas células / Study of the involvement of collagen V in lung cancer specifically in non-small cell carcinoma

Souza, Paola da Costa 09 September 2011 (has links)
O colágeno V vem emergindo como um potente indutor de morte celular (apoptose) via caspase. Nosso objetivo, neste estudo, foi examinar a interface entre o colágeno dos tipos I, III e V, apoptose tumoral e endotelial, angiogênese e células imunes, assim como o impacto desses fatores no prognóstico de pacientes com carcinomas não de pequenas células (CNPC) de pulmão. As amostras foram obtidas de 65 pacientes com CNPC de pulmão cirurgicamente excisados. Foram utilizados imunofluorescência e histomorfometria para colágenos I, III e V; imunohistoquímica e histomorfometria para avaliar apoptose endotelial e epitelial pelas caspases 5, 6, 8, 9 e via TUNEL, antiapoptose pela expressão do Bcl-2 e Bcl-6, densidade microvascular utilizando CD34, atividade vascular através da endotelina, VCAM e CD54, além da laminina. As células imunes foram imunomarcadas pelo CD3, CD4, CD8, CD20, CD56 Cd1a, S100, CD68 e as seguintes citocinas foram quantificadas: IL-4, IL-6, IL-8 e TGF-. O modelo de sobrevida de Cox mostrou que, quando controlados pelo estadiamento patológico linfonodal N, somente o colágeno do tipo V e a apoptose endotelial via caspase-9 foram significativamente associados com a sobrevida. Uma medida de corte ao nível da mediana para o colágeno do tipo V e caspase-9 dividiu os pacientes em dois grupos distintos de prognóstico. Aqueles com colágeno V maior do que 9,40% e apoptose vascular maior que 1,09% apresentaram baixo risco de morte (0,27 e 0,41, respectivamente), comparados com aqueles com colágeno V inferior a 9,40% e apoptose vascular inferior a 1,09%. Foi observada também menor densidade de células imunes e citocinas no microambiente tumoral do que não tumoral. O modelo de sobrevida de Cox, associando todas as variáveis estudadas, mostrou que baixo risco de morte associou-se com tabagismo menor que 41 maços/ano, estadiamento linfonodal N0, tratamento cirúrgico, ao tipo histológico carcinoma de células escamosas, fração de linfócitos CD4 > 16,2%, macrófagos CD68 > 4,5%, citocina IL-4 > 0,8%, citocina IL-6 > 2,2%, células dendríticas Cd1a > 1,6% e colágeno V > 9,4%. Coletivamente, os dados indicaram que o CNPC de pulmão não desencadeou uma resposta imune efetiva no sítio tumoral. Além disso, baixa síntese no colágeno V e apoptose endotelial pela caspase-9 em CNPC de pulmão estão fortemente associadas à sobrevida, sugerindo que estratégias destinadas a prevenir a baixa síntese de colágeno V, baixos índices de apoptose e resposta imune inata e adaptativa têm impacto no prognóstico dos CNPC de pulmão e podem ser marcadores promissores em novas abordagens na imunoterapia, podendo, assim, ter grande impacto no tratamento do câncer de pulmão / Type V collagen emerging promise as inductor of death response (apoptosis) via caspase. Our aim was to verify the remodeling of the microenvironment by type V collagen, tumoral/vascular apoptosis, angiogenesis, immune response and their impact on prognosis of patients with non-small cell lung carcinomas (NSCLC). Collagen, apoptosis, angiogenesis and immune cells were examined in tumor tissues from 65 patients with surgically excised NSCLC. We used immunofluoresce, immunohistochemistry, morphometry, 3D reconstruction and real-time PCR to evaluate the amount, structure and mRNA chains expression of type V collagen, endothelium and epithelial apoptosis caspases 5, 6, 8, 9 and via TUNEL; anti-apoptotic expression Bcl-2 and Bcl-6; immune cells CD3, CD4, CD8, CD20, CD56 Cd1a, S100 and CD68 and IL-4, IL-6, IL-8 e TGF- cytokines; microvessel density (CD34) and vascular activity by endotelin, V-CAM and Cd54. Impact of these markers was tested on follow-up until death from recurrent lung cancer. Decreased and abnormal synthesis of collagen V leads to increased angiogenesis by low endothelial death rate, and low immune response. Cox model analysis demonstrated that controlled for N stage, just two variables were significantly associated with survival time: collagen V and endothelium apoptosis caspase 9 +. Once these two variables were accounted for, none of the others related to survival. A cutpoint at the median for collagen V and endothelium apoptosis caspase 9 divided patients into two groups with distinctive prognosis. Those with collagen V > 9.40% and endothelium apoptosis caspase 9 > 1.09% have low risk of death (0.27 and 0.41, respectively) than those with collagen V < 9.40% and endothelium apoptosis caspase 9 + < 1.09%.In addition low levels of immune cells and cytokines in the tumour environment when compared with non-tumour environment. Cox model analysis with all variables showed low risk of death for tabagism < 41 packs/year, N0 stage, SCC, CD4+ > 16.81%,macrophages/monocytes > 4.5%cytokine IL-4 > 0,8%, cytokines IL-6 > 2,2%, dendritic cells Cd1a > 1,6% and collagen V > 9,4%. Collectively, the data indicated that NSCLC did not trigger a substantive immune cell infiltrate at tumour sites. More over Collagen V and endothelium apoptosis caspase 9 + in resected NSCLC are strongly related to prognosis, suggesting that strategies aimed at preventing the low collagen V synthesis, or local responses to low endothelium apoptosis and immune cell infiltration has impact on NSCLC prognosis and may be a promising marker for new immunotherapeutic approaches and may have a greater impact in lung cancer
148

Análise e comparação da expressão imunoistoquímica de marcadores moleculares (ERCC1, Bcl-2, Lin28a e Ki67) potencialmente preditores de resposta à quimioterapia em carcinomas neuroendócrinos extra-pulmonares e carcinoma de pequenas células de pulmão / Evaluation of biomarkers (ERCC1, BCL-2, Lin28a e Ki67) potencially predictive of response and prognosis in patients with high-grade extrapulmonary neuroendocrine carcinomas or small cell lung cancer treated with platin-based chemotherapy

Rêgo, Juliana Florinda de Mendonça 21 November 2016 (has links)
INTRODUÇÃO: O carcinoma de pulmão de pequenas células (CPPC) e o carcinoma neuroendócrino (CNE) extra-pulmonar apresentam características histopatológicas e tratamentos similares, porém os desfechos encontrados nos dois grupos podem ser diferentes. Avaliamos a expressão de alguns biomarcadores e a associação destes com taxa de resposta (TR) à quimioterapia baseada em platina e sobrevida global (SG) nos dois grupos. METODOS: Realizamos estudo retrospectivo de pacientes com CPPC e CNE extra-pulmonares tratados com quimioterapia baseada em platina. Todas as amostras tumorais foram revisadas pelo mesmo patologista (R.S.S.M.) e analisadas quanto a expressão imunoistoquímica de Ki-67, ERCC1, Bcl-2 e Lin28a, a qual foi determinada através do H-escore (calculado multiplicando o produto da intensidade da coloração - 0 a 3 - com a porcentagem de células positivas - 0 a 100 -, podendo variar de 0 a 300 - positivo quando >= 200). Os biomarcadores foram analisados tanto como variáveis contínuas quanto categóricas e a TR foi determinada por RECIST 1.1. A associação entre a expressão de cada biomarcador e a TR foi avaliada através do teste de qui-quadrado ou teste exato de Fisher para variáveis categóricas e regressão logística simples para variáveis contínuas. Sobrevida global foi estimada por Kaplan-Meier e as curvas foram comparadas por log-rank. O modelo de regressão de cox foi utilizado para avaliar associação entre SG e a expressão de biomarcadores como variável contínua. RESULTADOS: Entre Julho de 2006 e Julho de 2014, 142 pacientes foram identificados: N=82 (57,7%) com CPPC e N=60 (42,3%) com CNE extra-pulmonar. As características clínicas eram semelhantes em ambos os grupos. Mediana de ki67 foi de 60% (7-100) no CPPC e de 50% (20-95%) no segundo grupo (p=0,858). Com uma mediana de 5 ciclos por paciente (N=123 elegíveis para análise de TR), a TR foi de 86,8% no CPPC, enquanto nos com CNE extra-pulmonar, foi de 44,6% (p < 0.001). A mediana de SG (N=132 elegíveis para análise da SG) foi similar entre os grupos (10,3 meses em CPPC e 11,1 meses em CNE extra-pulmonar; p=0,069). Não houve diferença no padrão de expressão do ERCC1 (p=0,277) e do Lin28a (p=0,051) entre os grupos. Bcl2 foi expresso em 38 pacientes (46,3%) com CPPC e em 17 pacientes (28,3%) com CNE extra-pulmonar (p=0,030). Apenas no grupo com CNE extra-pulmonar, a alta expressão do Bcl2 foi associada com pior prognóstico (8,0 meses vs 14,7 meses; p=0,025). A expressão dos demais marcadores em CNE extra-pulmonar e dos quatro em CPPC não apresentou influência sobre a SG, não havendo também associação entre estes e a taxa de resposta à quimioterapia. Dentre os pacientes com CNE extra-pulmonar, não houve diferença na SG ou na TR entre os pacientes com carcinoma bem diferenciado (N=13;) e com carcinoma pouco diferenciado (N=47). CONCLUSÃO: Apesar do CPPC e do CNE extra-pulmonar serem tratados de forma semelhante, nesta coorte a taxa de resposta entre os grupos foi significativamente diferente. Quando comparado com CPPC, os pacientes com CNE extra-pulmonar apresentam uma menor responsividade à quimioterapia baseada em platina, mas com tendência a maior SG. Dentre os CNE extra-pulmonares, a alta expressão de Bcl-2 foi associada a pior prognóstico. Os demais biomarcadores não apresentaram papel preditor de resposta ou prognóstico / INTRODUCTION: Small cell lung cancer (SCLC) and high-grade extrapulmonary neuroendocrine carcinomas (EPNEC) share similar histopathological features and treatment, but outcomes may differ. We evaluated the expression of biomarkers and their association with response rate (RR) to platin-based chemotherapy and overall survival (OS) in these entities. METHODS: We conducted a retrospective analysis of patients with advanced EPNEC and SCLC treated with platinum-based chemotherapy. A single pathologist (R.S.S.M.) revised all samples. Paraffin-embedded tumor samples were tested for Ki-67, ERCC1, Bcl-2 and Lin28a expression by immunohistochemistry (IHC). Final IHC score (H-score) was calculated multiplying the intensity of staining by grading (0-300, with >= 200 considered positive). Biomarkers were analyzed as both categorical and continuous variables. RR was determined by RECIST 1.1. Associations between each biomarkers expression and RR were assessed using Chi-square or Fisher\'s exact test for categorical variables and univariate logistic regression for continuous variables. OS was estimated by the Kaplan-Meier method and curves were compared by log-rank. Cox regression analysis was used to evaluate any association between biomarkers expression (continuous variables) and OS. RESULTS: From July 2006 to July 2014, 142 patients were identified: N=82 (57,7%) with SCLC and N=60 (42,3%) with EPNEC. Baseline clinical characteristics were similar. Median Ki67 was 60% (7-100) among SCLC patients and 50% (20-95%) in EPNEC (p=0,858). With a median of 5 cycles per patient in both groups (N=123 evaluable patients), the RR was significantly higher in the SCLC group (86,8% vs 44.6%; p < 0.001). Median OS (N=132 evaluable patients) was similar between the groups (10.3 months in SCLC and 11.1 months in EPNEC; p=0,069). In the EPNEC group, there wasn\'t any difference in OS or RR between the patients with welldifferentiated (N=13) and poorly differentiated carcinoma (N=47). ERCC1 (p=0.277) and Lin28a (p=0.051) were similarly expressed between the groups. Bcl2 was expressed in 38 SCLC patients (46.3%) and in 17 EPNEC patients (28.3%; p=0.030). Only in the EPNEC group, Bcl2 high expression was associated with worse survival (8.0 months vs 14.7 months; p = 0.025). RR to chemotherapy was not influenced by the expression of the ERCC1, Lin28a, Bcl-2, Ki-67 in either EPNEC or SCLC groups. CONCLUSION: Even though SCLC and EPNEC are treated similarly, in this cohort, the rate response differed significantly. When compared with SCLC, patients with EPNEC apparently had tumors less responsive to platin-based chemotherapy, but tended to live longer. In EPNEC treated with platin, high expression of Bcl2 was associated with poor prognosis. We could not identify additional predictive or prognostic biomarkers
149

Role of stroma and Wound Healing in carcinoma response to ionizing radiation / Rôle du stroma et la cicatrisation en réponse de carcinome à des rayonnements ionisants

Arshad, Adnan 03 July 2014 (has links)
Les phénomènes cicatriciels et de carcinogenèse partagent des points communs et peuvent être définis comme des processus complexes et adaptatif régulés par les interactions entre l'hôte et le microenvironnement tissulaire. Après la chirurgie, la radiothérapie est la seconde modalité la plus efficace dans le traitement du cancer et une approche thérapeutique multimodale impliquant chirurgie, radiothérapie et chimiothérapie est aujourd’hui classiquement utilisée. Des résultats récents suggèrent que, en plus des effets létaux sur les cellules tumorales, la radiothérapie modifie le microenvironnement tissulaire. Ces modifications affectent le phénotype cellulaire, le métabolisme des tissus, et les événements de signalisation entre les cellules.Les interactions complexes entre les cellules stromales et les cellules cancéreuses suscitent beaucoup d’intérêt et dans la première partie de ma thèse, j’ai exploré les interactions entre stroma et cellules de carcinome en réponse à la radiothérapie par modulation génétique du stroma après irradiation. J’ai constaté que les fibroblastes, indépendamment de leur statut RhoB, ne modulaient pas la radiosensibilité intrinsèque des TC- 1, mais produisaient des facteurs diffusibles capables de modifier le devenir des cellules tumorales. Ensuite, j’ai constaté que fibroblastes sauvages et RhoB déficients stimulaient la migration des TC-1 par des mécanismes distincts, impliquant respectivement TGF- β1 et MMP. J’ai également constaté que la co-irradiation, des fibroblastes et des TC- 1, abrogait le phénotype pro-migratoire des TC-1 par répression de la sécrétion du TGF- β et des MMP. Alors que le protocole de co-irradiation utilisé mime la situation clinique, mes résultats sont en désaccord avec les publications récentes et suggèrent que le stroma irradié ne renforce pas la migration des cellules tumorales mais au contraire pourrait être manipulé pour promouvoir une réponse immunitaire anti-tumorale.Deuxièmement, mes expériences in vivo, semblent confirmer les données obtenues in vitro et montrent que l’irradiation préalable du lit tumoral ne stimule ni croissance de la tumeur et ni sa dissemination. Nos résultats semblent montrer que l’irradiation du stroma ne favorise pas la migration des cellules de carcinome et ceci indépendamment de leur génotype. La Troisième Partie De Mon Projet, a été consacrée à l’étude des cellules tumorale circulantes (CTC) après la radiothérapie. En accord avec les résultats rapportés après la chirurgie, le nombre de CTC augmente dans la circulation sanguine après radiothérapie probablement à cause des lésions vasculaires radio-induites ou/et par induction d’EMT dans les cellules tumorales. Néanmoins ces CTC semblent être piégées dans la cavité cardiaque. La signification de la présence de ces CTC pour le développement métastatique n’est pas élucidée mais on peut suspecter un effet promoteur de métastase. Ainsi le microenvironnement pourrait avoir des effets antagonistes promoteurs ou inhibiteurs de malignité. / Wound healing and carcinogenesis are defined as complex, adaptive processes which are controlled by intricate communications between the host and the tissue microenvironment. A number of phenotypic similarities are shared by wounds and cancers in cellular signaling and gene expression. Radiotherapy is the second most effective modality of cancer treatment after surgery and can be used, either alone or in combination with chemotherapy. Recent findings suggest that radiotherapy apart from tumor cell death also rapidly and persistently modifies the tissue microenvironment. These modifications affect cell phenotype, tissue metabolism, bidirectional exchanges and signaling events between cells. The complex interactions between stromal cells and cancer cells are of immense interest and in The First Part of My Thesis, I tried to explore the crosstalk between stromal and carcinoma cells in response to radiotherapy by genetic modulation of the stroma and irradiation. We found that fibroblasts, irrespective of their RhoB status, do not modulate intrinsic radiosensitivity of TC-1 but produce diffusible factors able to modify tumor cell fate. Then we found that Wt and RhoB deficient fibroblasts stimulated TC-1 migration through distinct mechanisms respectively, TGF-β1 and MMP-mediated. We also found that co-irradiation of fibroblasts and TC-1 abrogated the pro-migratory phenotype by repression of TGF-β and MMP secretion. This result is highly relevant to the clinical situation and suggests that conversely to, the current view; irradiated stroma would not enhance carcinoma migration and could be manipulated to promote anti-tumor immune response. Secondly, our in vivo experiments, tends to confirm the in vitro data showing that irradiated tumor bed does not stimulate tumor growth and escape. Our results also challenges the view that irradiated stroma would promote migration of carcinoma cells as we show that independently from their genotype co-irradiation of fibroblasts and carcinoma cells repressed carcinoma cell migration and confirmations studies are currently performed in vivo. The Third Part of My Project, was dedicated to investigate the effect on CTC release after radiotherapy. Consistently with the results reported after surgery , the number of CTC increases in the blood stream after radiotherapy probably due to radiation-induced vascular injury induced or/and by EMT induction in tumor cells but these cells seemed to be entrapped into the cardiac cavity. The significance of these CTC to metastatic development is still under investigation but there is evidence for a metastasis-promoting effect of RT from animal studies.Thus the microenvironment can exert antagonist stimulatory or inhibitory effects on malignant cells.
150

Immunogenetic determinants of chemotherapy response in cancer / Rôle du profile immunogénétique des patientes dans la réponse à la chimiothérapie

Vacchelli, Erika 15 September 2014 (has links)
L’efficacité de la chimiothérapie contre la croissance tumourale repose sur l'induction d'une mort des cellules tumourales dite immunogène. Les cellules tumourales mourantes agissent alors comme un vaccin thérapeutique en stimulant une réponse immunitaire anti-tumourale capable de contrôler, voire d'éliminer, les cellules cancéreuses résiduel. Les trois marqueurs principales de la mort cellulaire immunogène (MCI), sont (i) l'exposition pré-apoptotique de la calréticuline (CRT) à la surface des cellules, (ii) la sécrétion de l'ATP pendant l'apoptose qui dépend du processus d'autophagie, et (iii) le relargage post-apoptotique de la protéine non-histone de fixation à la chromatine HMGB1 (High Mobility Group B1). CRT, ATP et HMGB1 se lient respectivement à CD91, au récepteur purinergique P2RX7 (Purinergic Receptor P2X, ligand-gated ion channel 7) et au récepteur TLR4 (Toll-like Receptor 4) situés à la surface des cellules dendritiques. En retour, ces interactions initient respectivement la phagocytose des cellules mourantes, la production de l'interleukine-1β et la cross-présentation des antigènes tumouraux aux lymphocytes T.Notre laboratoire a précédemment démontré que la chimiothérapie adjuvante présente une efficacité réduite chez des patients atteints de cancers colorectaux et du sein portant un polymorphisme d'un seul nucléotide ou SNP (Single-Nucleotide Polymorphism) compromettent la fonction des gènes P2RX7 et TLR4, notamment rs3751143 (496Glu>Ala) pour le gène P2RX7 et rs4986790 (299Asp>Gly) pour le gène TLR4.Compte tenu des ces résultats que mettent en évidence la relation étroite entre l’efficacité de la chimiothérapie anticancéreuse et un système immunitaire opérationnel, nous avons décidé d'étudier l'effet de ces SNPs, soit sur la survie globale soit sur la survie sans événement, chez des patients atteints de cancer pulmonaire non à petites cellules ou NSCLC (Non-Small Cell Lung Carcinoma) et de cancers de la tête et du cou ou HNSCC (Head and Neck Squamous Cell Carcinoma). De plus, nous avons porté notre attention sur un autre SNP affectant le gène ATG16L1 (Autophagy-related 16-Like 1), notamment rs2241880 (300Thr>Ala) qui compromet l’activité d’un gène fondamental dans le processus d’autophagie.Dans les cancers NSCLC, les allèles mutants "perte de fonction" des gènes ATG16L1, P2RX7 et TLR4 n'affectent pas la survie globale, indépendamment du type de chimiothérapie administrée. Au contraire, les patientes atteintes de HNSCC, portant au moins un allèle "perte de fonction" d’ATG16L1 et TLR4, présentent un taux de survie sans récidive inferieure par rapport aux patients qui présentent un genotype sauvage. Ce travail décrit pour la première fois un biomarqueur prognostique pour ce type de cancer.De plus, nous avons pu définir, par génotypage à haut débit, une signature de SNPs prédictive de la réponse à la chimiothérapie neoadjuvantes à base d'anthracyclines et des taxanes chez les patients atteints de cancer du sein. En particulier, la combinaison des deux paramètres clinicopathologiques classiques (âge lors du diagnostic et récepteur aux œstrogènes) avec les génotypes rs1076669 du gène ECE1 (Endothelin Converting Enzyme 1; 341Thr>Ile) et rs2277413 du gène PZP (Pregnancy-Zone Protein; 813Val>Ala) a permis de définir trois grandes catégories des patients et leur probabilité respective d'atteindre la réponse complète pathologique après traitement.L'identification de nouveaux biomarqueurs associés à une absence/diminution de réponse à la chimiothérapie apparaît critique pour choisir des alternatives thérapeutiques appropriées et éviter les effets secondaires indésirables chez les non-répondeurs. / Successful chemotherapeutics can induce a type of tumour cell death that is immunogenic, implying that patient’s dying cancer cells function as a therapeutic vaccine and elicit an anti-tumour immune response that controls the residual disease. The three main hallmarks of immunogenic cell death (ICD) are the pre-apoptotic exposure of calreticulin (CRT) on the cell surface, the autophagy-dependent secretion of ATP during the blebbing phase of apoptosis and the post-apoptotic release of the chromatin-binding non-histone protein high mobility group B1 (HMGB1). CRT, ATP and HMGB1 interact with CD91, purinergic receptor P2X, ligand-gated ion channel, 7 (P2RX7) and Toll-like receptor 4 (TLR4), respectively, on the surface of dendritic cells (DCs), thus promoting the engulfment of dying cells, the production of IL-1β and the cross-presentation of tumour-associated antigens to T cells, respectively.Our laboratory has demonstrated that adjuvant chemotherapy exhibits a reduced efficacy in breast and colorectal cancer patients bearing single-nucleotide polymorphisms (SNPs) that compromise the function of P2RX7 or TLR4, such as rs3751143 in P2RX7 (Glu496Ala) and rs4986790 in TLR4 (Asp299Gly).Driven by these results, underpinning the intimate relationship between the success of anti-cancer chemotherapy and an operational immune system, we decided to investigate the effect of these SNPs on disease outcome among non-small cell lung carcinoma (NSCLC) and head and neck squamous cell carcinoma (HNSCC) patients. Additionally, we focused our attention on a SNP in autophagy related 16-like 1 (ATG16L1), namely rs2241880 (Thr300Ala), which compromises the activity of one pivotal autophagic gene. In NSCLC patients, loss-of-function ATG16L1, P2RX7 and TLR4 alleles do not affect overall survival, irrespective of the administration and type of chemotherapy. Conversely, HNSCC patients bearing at least one loss-of-function ATG16L1 or TLR4 allele exhibit a reduced disease-free survival when compared to their wild-type counterparts. This is the first report highlighting a putative prognostic biomarker for this malignancy. Furthermore, taking advantage of a high throughput genotyping study, we delineated a SNP-based signature that predicts the response of breast cancer patients to anthracycline- and taxane-based neoadjuvant chemotherapy. Particularly, the combination of two classical clinicophatological parameters (age at diagnosis and estrogen receptor) and genotype at the ECE1 (rs1076669 Thr341Ile) and PZP (rs2277413 Val813Ala) loci allowed us to define three broad categories with a correspondent probability of achieving pathological complete response. The identification of new biomarkers associated with a reduced/absent response to chemotherapy appears critical for selecting appropriate therapeutic alternatives, and avoiding undesired side effects among non-responders.

Page generated in 0.0418 seconds