No description available.

Ziel dieser Studie war es, die Häufigkeit der Expression von EGFR, HER-2 sowie COX-2 im Zervixkarzinom zu eruieren. Dabei galt es herauszufinden, ob Unterschiede hinsichtlich des Nachweises dieser drei, möglicherweise therapeutisch relevanten Moleküle zwischen den primären, nicht vortherapierten und operierten Karzinomen und den multimodal vorbehandelten Rezidiven gab. In der vorliegenden retrospektiven Arbeit wurden 45 TMMR-operierte Primärtumoren und 28 LEER-operierte Rezidivtumoren der Universitätsfrauenklinik Leipzig (Triersches Institut) einbezogen und zusätzlich hinsichtlich der prognostischen Überlebensanalyse durch das Tumorstadium, Lymphknotenmetastasen und Rezidivauftreten sowie histologischer Charakteristika untersucht. Dazu wurden Tissue - Microarrays angefertigt mit anschließender immunhistochemischer Untersuchung dieser. Die Ergebnisse zeigten, dass die TMMR-Operation die Überlebensprognose signifikant verbessert, denn lediglich bei den LEER-therapierten Rezidivtumoren erlitten die Patientinnen sowohl Fernmetastasen als auch erneute Rezidive. Weder die Expression der drei untersuchten Moleküle noch die histopathologischen Parameter haben eine prognostische Relevanz. Es gibt keine signifikanten Zusammenhänge zwischen der Häufigkeit der Expression von EGFR, HER-2 sowie COX-2 und Primär-, bzw. Rezidivtumoren, sodass diese Moleküle keine Targets für eine individualisierte, zielgerichtete Therapie beim Zervixkarzinom darstellen.

No description available.

<p>To further develop cancer therapy, targeted delivery of cell killing agents directly to tumor cells is an interesting approach. This thesis describes the development of PEG-stabilized liposome conjugates targeting either epidermal growth factor receptor (EGFR) using its natural ligand EGF, or human epidermal growth factor receptor 2 (HER-2) using the antibody trastuzumab. Both receptors are known to be overexpressed on a variety of tumors. The liposomes were loaded with the boronated compounds water soluble boronated acridine (WSA) or water soluble boronated phenantridine (WSP), compounds primarily developed for boron neutron capture therapy, BNCT. </p><p>The liposome conjugates bound specifically to their receptors in cell culture. Because the WSA conjugates exhibited the most favorable boron uptake this compound was chosen for further study. The WSA-loaded liposome conjugates was internalized, an important characteristic for BNCT, and had a long retention inside the cells. The cellular localization of WSA, studied using fluorescence was found to be mainly cytoplasmic. </p><p>To increase the boron uptake studies comparing different incubation methods was performed. It was shown for both EGF and trastuzumab targeted liposomes the uptake could be increased over 10 times by changing from incubation in monolayer culture to incubation in cell suspension in roller flasks. With this treatment the boron concentrations reached after 24 h incubation time was 90 ppm for EGF-liposomes and 132 ppm for trastuzumab-liposomes, levels that are clinically interesting. </p><p>To study the cell-killing efficacy of the liposome-conjugates an experimental BNCT study was performed using EGF-liposome-WSA on cultured glioma cells. About half the number of thermal neutron was needed to inactivate 90% of the cells if the cells had been incubated with EGF-liposome-WSA compared to control cells. When comparing the survival to dose it was shown that to inactivate 90% of the cells 2.9 Gy was needed for EGF-liposome-WSA and neutrons compared to 5.6 Gy with ¹³⁷Cs gamma. </p><p>The biodistribution of EGF-liposomes was also studied in mice. It was compared to EGF and it was found that the addition of a PEG-stabilized liposome to EGF significantly reduced EGF uptake in liver and kidneys, the circulation time in blood was prolonged as well. The reduced liver uptake might be due to inability of the 100 nm liposomes to pass the sinusoidal fenestrations of the liver and bind to the EGFR-rich hepatocytes. The reduced liver uptake potentates the use of EGF-liposome conjugates for systemic injection.</p>

To further develop cancer therapy, targeted delivery of cell killing agents directly to tumor cells is an interesting approach. This thesis describes the development of PEG-stabilized liposome conjugates targeting either epidermal growth factor receptor (EGFR) using its natural ligand EGF, or human epidermal growth factor receptor 2 (HER-2) using the antibody trastuzumab. Both receptors are known to be overexpressed on a variety of tumors. The liposomes were loaded with the boronated compounds water soluble boronated acridine (WSA) or water soluble boronated phenantridine (WSP), compounds primarily developed for boron neutron capture therapy, BNCT. The liposome conjugates bound specifically to their receptors in cell culture. Because the WSA conjugates exhibited the most favorable boron uptake this compound was chosen for further study. The WSA-loaded liposome conjugates was internalized, an important characteristic for BNCT, and had a long retention inside the cells. The cellular localization of WSA, studied using fluorescence was found to be mainly cytoplasmic. To increase the boron uptake studies comparing different incubation methods was performed. It was shown for both EGF and trastuzumab targeted liposomes the uptake could be increased over 10 times by changing from incubation in monolayer culture to incubation in cell suspension in roller flasks. With this treatment the boron concentrations reached after 24 h incubation time was 90 ppm for EGF-liposomes and 132 ppm for trastuzumab-liposomes, levels that are clinically interesting. To study the cell-killing efficacy of the liposome-conjugates an experimental BNCT study was performed using EGF-liposome-WSA on cultured glioma cells. About half the number of thermal neutron was needed to inactivate 90% of the cells if the cells had been incubated with EGF-liposome-WSA compared to control cells. When comparing the survival to dose it was shown that to inactivate 90% of the cells 2.9 Gy was needed for EGF-liposome-WSA and neutrons compared to 5.6 Gy with 137Cs gamma. The biodistribution of EGF-liposomes was also studied in mice. It was compared to EGF and it was found that the addition of a PEG-stabilized liposome to EGF significantly reduced EGF uptake in liver and kidneys, the circulation time in blood was prolonged as well. The reduced liver uptake might be due to inability of the 100 nm liposomes to pass the sinusoidal fenestrations of the liver and bind to the EGFR-rich hepatocytes. The reduced liver uptake potentates the use of EGF-liposome conjugates for systemic injection.

<p>Noble metal nanoparticles exhibit unique optical properties that are beneficial to a variety of applications, including molecular imaging. The large scattering cross sections of nanoparticles provide high contrast necessary for biomarkers. Unlike alternative contrast agents, nanoparticles provide refractive index sensitivity revealing information regarding the local cellular environment. Altering the shape and composition of the nanoparticle shifts the peak resonant wavelength of scattered light, allowing for implementation of multiple spectrally distinct tags. In this project, nanoparticles that scatter in different spectral windows are functionalized with various antibodies recognizing extra-cellular receptors integral to cancer progression. A hyperspectral imaging system is developed, allowing for visualization and spectral characterization of cells labeled with these conjugates. Various molecular imaging and microspectroscopy applications of plasmonic nanoparticles are then investigated. First, anti-EGFR gold nanospheres are shown to quantitatively measure receptor expression with similar performance to fluorescence assays. Second, anti-EGFR gold nanorods and novel anti-IGF-1R silver nanospheres are implemented to indicate local cellular refractive indices. Third, because biosensing capabilities of nanoparticle tags may be limited by plasmonic coupling, polarization mapping is investigated as a method to discern these effects. Fourth, plasmonic coupling is tested to monitor HER-2 dimerization. Experiments reveal the interparticle conformation of proximal HER-2 bound labels, required for plasmonic coupling-enhanced dielectric sensing. Fifth, all three functionalized plasmonic tags are implemented simultaneously to indicate clinically relevant cell immunophenotype information and changes in the cellular dielectric environment. Finally, flow cytometry experiments are conducted utilizing the anti-EGFR nanorod tag to demonstrate profiling of receptor expression distribution and potential increased multiplexing capability.</p> / Dissertation

Thesis (Ph.D.)--Georgetown University, 2009. / Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 273-291).

No description available.

Ziel dieser Studie war es, die Häufigkeit der Expression von EGFR, HER-2 sowie COX-2 im Zervixkarzinom zu eruieren. Dabei galt es herauszufinden, ob Unterschiede hinsichtlich des Nachweises dieser drei, möglicherweise therapeutisch relevanten Moleküle zwischen den primären, nicht vortherapierten und operierten Karzinomen und den multimodal vorbehandelten Rezidiven gab. In der vorliegenden retrospektiven Arbeit wurden 45 TMMR-operierte Primärtumoren und 28 LEER-operierte Rezidivtumoren der Universitätsfrauenklinik Leipzig (Triersches Institut) einbezogen und zusätzlich hinsichtlich der prognostischen Überlebensanalyse durch das Tumorstadium, Lymphknotenmetastasen und Rezidivauftreten sowie histologischer Charakteristika untersucht. Dazu wurden Tissue - Microarrays angefertigt mit anschließender immunhistochemischer Untersuchung dieser. Die Ergebnisse zeigten, dass die TMMR-Operation die Überlebensprognose signifikant verbessert, denn lediglich bei den LEER-therapierten Rezidivtumoren erlitten die Patientinnen sowohl Fernmetastasen als auch erneute Rezidive. Weder die Expression der drei untersuchten Moleküle noch die histopathologischen Parameter haben eine prognostische Relevanz. Es gibt keine signifikanten Zusammenhänge zwischen der Häufigkeit der Expression von EGFR, HER-2 sowie COX-2 und Primär-, bzw. Rezidivtumoren, sodass diese Moleküle keine Targets für eine individualisierte, zielgerichtete Therapie beim Zervixkarzinom darstellen.