No / Background: Previous studies have shown extensive vascularisation surrounding subcutaneously implanted fibres when the duration of the US National Cancer Institute (NCI) hollow fibre assay was prolonged. Materials and Methods: The feasibility of adapting the NCI assay for evaluating agents targeting the tumour vasculature was investigated in vitro and in vivo. Finally, in the optimised assay, changes in neovasculature formation around the fibres following treatment with the anti-vascular agent paclitaxel were quantified by immunohistochemistry. Results: Correlations between cell number seeded, time in culture and vascular endothelial growth factor (VEGF) secretion were seen. In vivo studies showed that transplanting single rather than 3 fibres at a site reduced inflammation, reducing the length of the fibre transplanted, as did without any significant loss in cell growth over 21 days. A statistically significant reduction in neovascularisation surrounding the fibres was seen accompanying paclitaxel treatment. Conclusion: Modifications made here to the NCI hollow fibre assay demonstrate its potential for analysing anti-tumour vasculature agents.

Yes / Glycogen synthase kinase-3 (GSK3) is over-expressed and hyperactivated in non-small cell lung carcinoma (NSCLC) and plays a role in ensuring the correct alignment of chromosomes on the metaphase plate during mitosis through regulation of microtubule stability. This makes the enzyme an attractive target for cancer therapy. We examined the effects of a selective cell-permeant GSK3 inhibitor (CHIR99021), used alone or in combination with paclitaxel, using an in vitro cell growth assay, a quantitative chromosome alignment assay, and a tumor xenograft model. CHIR99021 inhibits the growth of human H1975 and H1299 NSCLC cell lines in a synergistic manner with paclitaxel. CHIR99021 and paclitaxel promoted a synergistic defect in chromosomal alignment when compared to each compound administered as monotherapy. Furthermore, we corroborated our in vitro findings in a mouse tumor xenograft model. Our results demonstrate that a GSK3 inhibitor and paclitaxel act synergistically to inhibit the growth of NSCLC cells in vitro and in vivo via a mechanism that may involve converging modes of action on microtubule spindle stability and thus chromosomal alignment during metaphase. Our findings provide novel support for the use of the GSK3 inhibitor, CHIR99021, alongside taxol-based chemotherapy in the treatment of human lung cancer. / Cancer Research UK Project Grant (C16929/A14402) and the Elizabeth Blackwell Institute, through its Wellcome Trust ISSF Award (105612/Z/14/Z). The Imperial NIHR/Biomedical Research Centre and the CR-UK/Dept of Health funded Imperial Experimental Cancer Medicine Centre.

The purpose of this thesis was to evaluate and compare the peripheral dose associated with VMAT lung SABR treatments for 10X, 6X, and 10X-FFF beams. Flattening Filter Free (FFF) radiotherapy photon beams exhibit high dose rates as compared to standard flattened photon beams. The high dose rates available with FFF beams make them ideal for high dose treatments, such as Volumetric Modulated Arc Therapy (VMAT)-delivery lung Stereotactic Ablative Radiotherapy (SABR), where treatment delivery is longer than that of standard treatments. They are also known to show reductions in treatment head scatter, multi-leaf collimator (MLC) transmission and treatment head leakage radiation, compared to flattened beams. The use of FFF beams for VMAT lung SABR has been shown to significantly reduce treatment delivery time, while maintaining plan quality and accuracy. Another potential advantage of the use of FFF beams for VMAT lung SABR is the reduction in peripheral (out-of-field) dose, due mainly to the reduction in head scatter and treatment head leakage. The peripheral doses delivered by VMAT Lung SABR treatments using 10X-FFF, 10X and 6X were investigated for the Varian TrueBeam medical linear accelerator. There were three components to this investigation; (1) Ion chamber measurement of peripheral dose for static open, static MLC and dynamic MLC fields, (2) Validation of Monte Carlo, Acuros XB and AAA algorithms for peripheral dose prediction, and (3) Evaluation of peripheral doses for VMAT lung SABR treatments using the validated Monte Carlo model. Measurements of out-of field doses for static open, static MLC and dynamic MLC fields showed that 10X-FFF delivered peripheral doses in the range of 30% to 50%, 3% to 40% and 5% to 20% lower than the peripheral doses for flattened beams. Dose calculation algorithm validation showed that AAA and Acuros XB significantly under predicted the dose in the peripheral region. Monte Carlo was found to be the most accurate dose calculation algorithm for peripheral dose prediction. The VMAT lung SABR dose distributions were calculated for both static gantry delivery and arc delivery using the validated Monte Carlo model. For static gantry Monte Carlo simulation, 10X-FFF was found to show a reduction in peripheral dose in the range of 7% to 21% and 7% to 17% when compared to 6X and 10X. For arc delivery Monte Carlo simulation, 10X-FFF was found to deliver a statistically significant reduction in mean peripheral dose compared to 6X in four of the six cases, and was not found to deliver a statistically significant reduction in mean peripheral dose compared to 10X in any of the six cases. For this type of VMAT lung SABR treatment, 10X-FFF offers a reduction in peripheral dose over 6X. In terms of the benefits of using 10X-FFF for this type of treatment, the reduction in peripheral dose is added to the already-established reduction in treatment times. / Graduate / 0756 / 0574

Les données existantes sur le rôle de l’autophagie dans la mort cellulaire radio-induite sont controversées et proviennent d’études pour lesquelles sont utilisées des drogues : l’action se produit donc de manière indirecte. Certains suggèrent que l’induction combinée de l’apoptose et de l’autophagie améliore le traitement par radiations ionisantes. D’autres indiquent que l’induction de l’autophagie favoriserait la radiorésistance des cellules tumorales et que l’utilisation d’inhibiteurs de l’autophagie augmenterait la réponse des tumeurs aux radiations ionisantes. L'autophagie, ou «self-eating», est un processus cellulaire activé par diverses conditions de stress, par lequel les cellules peuvent dégrader les protéines et les organites. Nous avons au cours de cette étude cherché à déterminer le rôle de l'autophagie dans la mort cellulaire radio-induite. Selon nos observations, l'autophagie est nécessaire pour la libération de l'ATP après un traitement par radiothérapie: en effet, le knockdown de gènes essentiels à l'autophagie limite la sécrétion d'ATP. Nous avons également constaté que des cellules déficientes pour l'autophagie traitées par radiothérapie sont incapables d’immuniser des souris contre une injection de cellules vivantes. En outre, les tumeurs déficientes pour l’autophagie répondent moins bien à un traitement par radiations ionisantes dans des souris immunocompétentes et continuent à proliférer, contrairement aux tumeurs “wild-type”. De plus, nous avons montré que les cellules déficientes pour l'autophagie ne sont pas en mesure de recruter des cellules dendritiques dans le lit tumoral. A l'inverse, l'inhibition des enzymes de dégradation de l’ATP extracellulaire accroît les concentrations d'ATP dans les tumeurs déficientes pour l'autophagie, ce qui rétablit le recrutement des cellules immunitaires dans le lit tumoral et restaure la réponse à la radiothérapie des cancers déficients pour l'autophagie. Ainsi, cette étude a montré l'importance de l'autophagie dans la réponse anti-tumorale spécifique, après traitement par radiations ionisantes. Ces résultats ouvrent de nouvelles perspectives pour comprendre la mort cellulaire radio-induite. Il reste cependant à découvrir les mécanismes moléculaires sous-jacents pour développer de nouvelles thérapies ciblées qui amélioreront l’efficacité de la radiothérapie. / Most of the available data on autophagy and tumor response to IR comes from indirect conclusions after concomitant drug-IR exposure. Some authors suggest that concurrent induction of apoptosis and autophagy enhances radiation therapy. Oppositely, others indicate that the induction of autophagy contributes to the radioresistance of tumor cells and suggest that autophagy inhibitors may be employed to increase the sensitivity radioresistant tumors cells to ionizing radiation. Autophagy literally ‘self-eating’ is a cellular process activated in response to various conditions of cellular stress, whereby cells can liberate energy resources via the degradation of proteins and organelles. In this project we aimed to determine the potential role of autophagy in IR –induced cell death. We found that autophagy is required for the release of ATP in response to radiotherapy, as we observed that the knockdown of essential autophagy-related genes abolished its secretion. Furthermore, autophagy deficient tumors growing on immunocompetent mice did not respond to radiotherapy and continued proliferating in contrast to autophagy proficient tumors. We showed that autophagy deficient cells were neither able to recruit DCs into the tumor bed. Conversely, the inhibition of extracellular ATP degrading enzymes increased extracellular ATP concentrations in autophagy deficient tumors, which reestablished the recruitment of immune cells into the tumor bed, and restored radiotherapeutic responses in autophagy-deficient cancers.Altogether, this study showed the importance of autophagy in tumor-specific immune response after radiotherapy. Thus giving new insights into the concept of IR-induced cell death. However, there is still much that is unknown about molecular mechanisms that undergo IR-induced cell death. Understand these molecular mechanisms will help to develop new targeted therapies that will improve the effectiveness of radiotherapy.

Non-small cell lung carcinoma is a leading cause of cancer mortality worldwide. There are gender and smoking associated differences both in tumour types and clinical outcome. Squamous cell carcinomas (SCC) are more frequent among smoking men while females develop adenocarcinomas (ADCA). NSCLC among never smokers are mainly ADCA, and occurs mostly in females. The present thesis elucidates the role of estrogen receptor (ER) and epidermal growth factor receptor family (EGFR/HER2-4) in NSCLC in the perspective of gender and histology as well as the influence of smoking on those biomarkers. A recently developed technique, tissue micro array (TMA), was employed.The question of how much of a tumour tissue that needed to be included in a TMA for biomarker analysis was analyzed by a statistical approach. Data indicates a sample size of three cylinders of tumour tissue with a diameter of 0.6 mm each as being appropriate and cost-effective. In order to optimally use the up to thousands of different tumour samples within a TMA, it would be optimal to serially cut and store slides before performing in situ detection of proteins and nucleic acids. Applying up to date methodology, and by evaluation with image analysis, data are presented that shows that such handling of TMA slides would be possible without any loss of biomarker information. ERα is more frequently observed in ADCA and in females and a local estradiol synthesis is supported by the presence of aromatase. ERβ is identified as a positive prognostic marker in ADCA. Smoking is associated to increased levels of ERβ mRNA. EGFR over expression is associated with a ligand. Independent phosporylation of ERα. HER-4 intracellular domain may also act as a co-activator to ERα in ADCA, especially among neversmokers. The question of ER and EGFR family signalling crosstalk as a potential target for combined targeted therapy is raised.

Dissertation (Ph.D.) -- University of Texas Southwestern Medical Center at Dallas, 2008. / Vita. Bibliography: p. 174-213.

Με την εργασία έγινε μελέτη του σηματοδοτικού μονοπατιού Sonic Hedgehog σε 96 περιστατικά καρκίνου πνεύμονα με τη μέθοδο της ανοσοϊστοχημείας. Επίσης μελετήσαμε την πιθανή συμμετοχή του μεταγραφικού παράγοντα FoxM1 στο καρκίνωμα του πνεύμονα και την πιθανή συσχέτισή του με το μονπάτι του Hedgehog. Έγινε μελέτη της έκφρασης των μορίων Shh, Ptch1, Smo, Gli1, Gli2 και FoxM1. Τα αποτελέσματα αποκάλυψαν μια έντονη έκφραση των μορίων του μονοπατιού και αυξημένα ποσοστά ενεργοποίησής του. Επίσης βρέθηκε στατιστικά σημαντική συσχέτιση με τα πλακώδη καρκινώματα και με τα χαμηλού grade καρκινώματα. Ανάλογη σημαντική συσχέτιση βρέθηκε και με το φύλο,συχνότερα ενεργοποιημένο μονοπάτι στους άντρες. Ακόμα ανιχνεύτηκε μια συσχέτιση της έκφρασης του FoxM1 με το ενεργοποιημένο μονοπάτι. / The hedgehog (HH)-signaling pathway is implicated in developmental processes and its aberrant activation in adult tissues has been associated with malignancy. The aim of this study was to determine the expression pattern of HH-signaling molecules in lung carcinomas, as well as the involvement of the transcription factor FOXM1, that controls cell proliferation, in this process. Paraffin-embedded tissue sections of 96 lung cancer cases and adjacent non-neoplastic lung parenchyma were immunohistochemically analyzed with anti-SHH, anti-Patched1 (PTCH1), anti-Smoothened (SMO), anti-GLI1, anti-GLI2 and anti-FOXM1 antibodies. Correlations of HH molecules with clinicopathological parameters and FOXM1 expression were evaluated. All the HH-signaling molecules examined were overexpressed in lung cancer compared with the adjacent non-neoplastic lung parenchyma. HH pathway activity and expression of PTCH1 and SMO were significantly higher in squamous cell carcinomas compared to other histological types. Activation of HH pathway and PTCH1 expression were correlated with tumor grade being higher in low grade tumors. There was a significant correlation of lymph node metastases with expression of SMO in all histological types and with the gender higher in men. Overexpression of FOXM1 in lung cancer was also significantly correlated with PTCH1, SMO and GLI1 expression. In conclusion, HH-signaling pathway is activated in lung cancer and correlates with histological type, prognostic parameters of the tumors as well as with the increased expression of FOXM1.

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.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Le facteur de transcription Nrf2 et les enzymes pro-angiogéniques: hème oxygénase (HO-1) et thymidine phosphorylase (TP) sont considérés comme des cibles potentielles pour les traitements combinatoires anticancéreux contre l’angiogenèse. L'objectif de la présente étude était d'examiner les interactions entre ces protéines dans la modulation du potentiel tumorigène et angiogénique de carcinome pulmonaire non à petites cellules (NSCLC). L’augmentation de l’expression de Nrf2 conduit à la réduction de la prolifération cellulaire et à leur capacité de migration, accompagnée d'une expression accrue de microARN suppresseurs de tumeurs ainsi qu’une réduction de l'oncogène miR-378. Ensuite, le rôle de TP dans les cellules NCI-H292 a été étudiée en la surexprimant in vitro (NCI-TP). Ceci a conduit à une atténuation de potentiel tumorigène comme le montre l'inhibition de la prolifération, de la migration et une amélioration concomitante de potentiel angiogénique qui est plus prononcée en hypoxie et en présence de thymidine. In vivo, les tumeurs NCI-TP ont tendance à croître plus rapidement que les témoins et ils sont également mieux oxygénés. Ces tumeurs ont une expression accrue de cytokines pro-inflammatoires IL-1β et IL-6. Nous avons montré pour la première fois que l’enzyme TP peut être régulé par Nrf2 et HO-1 dans les cellules NSCLC, ce qui peut affecter la croissance tumorale par une modulation de l'angiogenèse et de l'expression de facteurs pro-inflammatoires. La corrélation entre l’expression de TP avec celle de l'IL-1β et d'IL-6 a été également confirmée dans les échantillons cliniques de tumeurs issus de patients atteints de NSCLC. L’ensemble de nos résultats montre la potentialité de cibler l’enzyme TP pour le traitement des cancers NSCLC. / Nrf2, heme oxygenase-1 (HO-1) and thymidine phosphorylase (TP) are considered as potential targets for combinatorial anti-cancer therapies. The aim of the study was to investigate the interplay of these proteins in regulation of growth and angiogenesis in non-small cell lung carcinoma (NSCLC) cells NCI-H292. Stable overexpression of Nrf2 (NCI-Nrf2 cell line) resulted in decreased cell proliferation and migration in vitro, upregulation of tumor suppressor microRNAs and downregulation of oncogenic miR-378 and many MMPs. Silencing of HO-1 in NCI-Nrf2 cells partially reversed the effect on MMP-1, MMP-3 and miR-378. NCI-Nrf2 cells exhibited increased expression of proangiogenic factors IL-8, angiopoietin-1 and TP, which was also upregulated in cell overexpressing HO-1. In both models, the effect was TP reversible by siRNA targeted at HO-1 and possibly mediated by modulation of oxidative status of the cell. Moreover, it was observed that overexpression of TP in vitro attenuated proliferation and migration of NSCLC cells, but increased their angiogenic potential. In vivo, NCI-TP tumors tended to grow faster, were better oxygenated and exhibited increased expression of inflammatory cytokines IL-1β and IL-6. Correlation of TP with IL-1β and IL-6 was also confirmed in clinical samples from NSCLC patients. Overall, our results enforce the notion of targeting TP for treatment of NSCLC.