La lecture à portée de main
Découvre YouScribe en t'inscrivant gratuitement
Je m'inscrisDécouvre YouScribe en t'inscrivant gratuitement
Je m'inscrisDescription
Sujets
Informations
Publié par | ruprecht-karls-universitat_heidelberg |
Publié le | 01 janvier 2011 |
Nombre de lectures | 32 |
Langue | English |
Poids de l'ouvrage | 3 Mo |
Extrait
DISSERTATION
RGS4, CD95L and B7H3: Targeting evasive resistance
and the immune privilege of glioblastoma
Philipp‐Niclas Pfenning
2011
DISSERTATION
submitted to the
Combined Faculties for the Natural Sciences and for Mathematics
of the Ruperto‐Carola University of Heidelberg, Germany
for the degree of
Doctor of Natural Sciences
presented by
Diplom‐Biologe Philipp‐Niclas Pfenning
born in Heidelberg, Germany
Oral Examination: 06.05.2011
RGS4, CD95L and B7H3: Targeting evasive resistance
and the immune privilege of glioblastoma
Referees: Prof. Dr. Hilmar Bading
Prof. Dr. Wolfgang Wick
Dedicated to my wife
Acknowledgements
I wish to express my deepest gratitude to my thesis supervisor Prof. Dr. Wolfgang Wick for his
constant support and encouragement, his confidence and dynamism as well as for the excellent
working conditions.
I am thankful to Prof. Dr. Hilmar Bading for examination and for evaluation of my thesis, to PD Dr.
Karin Müller‐Decker and Dr. Marius Lemberg for examination and to Prof. Dr. Andreas von Deimling
for being a member of my PhD Thesis Advisory Committee.
My sincere thanks go to Dr. Markus Weiler for introducing me to the exciting field of glioma research
and for his supervision and scientific support. I would also like to thank Dr. Dieter Lemke for sharing
the project and for his precious ideas. Furthermore, I appreciate the additional tutorship of Prof. Dr.
Michael Platten and his ideas and suggestions.
I am very grateful to all my collaboration partners at the German Cancer Research Center, at the
University Hospital Heidelberg and at Apogenix GmbH for their valuable support and fruitful
contributions to the different projects of my thesis.
Special thanks go to Ulli Litzenburger for scientific and also not so scientific discussions as well as the
fun we had during the time we spent together in the lab and in the ‘outside world’.
I would like to thank all present and former lab members of the ‘G370 and G160’ for the good
working atmosphere, for scientific and practical support and all the things that would take up too
much space to be mentioned here. Special thanks in this regard to Jonas Blaes for being such a great
office mate. My thanks also go to Dr. Regine Garcia‐Boy for critical reading of the manuscript.
Further, I would like to thank my family and friends for encouragement throughout my PhD thesis.
Finally, I am deeply grateful to my beloved wife Katja for cheering me up over and over again and for
being the most supportive person in my life.
Summary
Glioblastoma are the most common primary brain tumors in adults with a median survival of one
year even with multimodal therapy including surgical resection, radiotherapy, and chemotherapy.
Important hallmarks of these tumors are vascular proliferation, diffuse invasion of tumor cells
into the surrounding brain tissue and effective suppression of the immune system. The efficacy of
resection and current radiochemotherapy treatment regimens are therefore extremely limited.
Both the genesis and development as well as the progression of malignant gliomas are highly
dependent on angiogenic processes, the formation of new blood vessels from pre‐existing
vessels. Current treatment strategies tested in clinical trials targeting tumor angiogenesis have so
far not been proven to increase survival of the patients. In addition to the insufficiency of clinical
trials done, this has been attributed to several potent evasion strategies occurring at disease
progression and recurrence, including increasing infiltrative tumor growth, commonly referred to
as ‘evasive resistance’. These invasive growth patterns occur in addition as responses to
radiotherapy and essentially trigger disease progression and have a strong influence on patients’
survival.
Parts of the work presented here address the challenge of targeting the evasive resistance in
glioblastoma in order to develop novel treatment strategies for a clinical application which
combine anti‐angiogenic with radio‐enhanced anti‐invasive modalities. Several strategies, focusing
on different molecular targets, were undertaken: (1) Activation of the PI3K/AKT/mTOR signaling
pathway is relatively common in human glioblastoma and is associated with poor survival. A
clinically relevant radiation‐enhanced inhibition of this&