MUDr. SKALICKÝ, Tomáš Five year period of experimental and clinical experience with radiofrequency ablation of liver tumors is described. RFA considerably extends the survival of patients with non-resectable liver metastases. The method has minimal complications and both mortality and morbidity are low.

No description available.

Glioblastoma (GBM) remains the most aggressive primary brain tumor in adults. Since 2005, Standard of Care (SoC) consists of surgical resection followed by radiation and adjuvant chemotherapy with temozolomide. Treatment failure is attributed to intratumoral heterogeneity with populations capable of mechanisms to repair damaged DNA. Given the lack of progress to improve patient outcomes, the current work encompasses how multi-omic approaches can be utilized to uncover novel biology in GBM and develop precision medicines to exploit these cancer specific phenomena. Using patient derived GBM samples I first used the surface marker CD133 to interrogate glioblastoma stem cells, a subpopulation of cells identified to withstand conventional therapies and lead to tumor relapse. I used a genome-wide CRISPR-Cas9 library to conduct an unbiased loss-of-function phenotypic screen to identify regulators of CD133. I then validated SOX2 as a direct transcription factor to PROM1 encoding CD133. These findings further show the untapped potential of CRISPR to uncover novel biology to directly apply to broader fields of stem cells and cancer biology. Next, I combed GBM data sets at transcriptomic and proteomic levels to identify understudied proteins as potential targets for immunotherapies. Glycoprotein nonmetastatic melanoma protein B (GPNMB) has previously been identified as a clinically relevant target in GBM and shown to be active in the tumor immune microenvironment. I found GPNMB to be upregulated in recurrent GBM and macrophage populations which can be exploited in a more comprehensive manner to treat GBM. Through a series of models, I elucidated how GPNMB influences GBM biology, its effectiveness as a target for Chimeric Antigen Receptor T-cells, and how it can be paired with CD133 therapies to provide better coverage of tumor cells. Together, these studies highlight how advances in pre-clinical models and technologies can be leveraged to develop new therapies in a rational manner. / Thesis / Doctor of Science (PhD) / Glioblastoma (GBM) remains an aggressive and incurable brain cancer despite decades of intense research. Treatment failure is due to the untargeted approaches currently undertaken in the clinic. The current work uses multiples methods to interrogate how GBM grows and develops over time. Using GBM samples from consenting patients, I investigated an important population of the tumor using a surface marker CD133 and CRISPR to study which genes influenced it. I then successfully validated SOX2 as a direct regulator of CD133 expression. Next, I combed multiple data sets for a target to kill GBM cells without harming healthy tissue in patients. I found Glycoprotein Non-Metastatic Melanoma Protein B (GPNMB) to be exploitable and used several experimental methods to investigate its role in GBM progression. Finally, we used a novel immunotherapy to eliminate cells which express GPNMB. Together, these findings could apply to the broader field of stem cell biology and be used for a more targeted method to eliminate the cancer entirely.

In this study the mouse tumor necrosis factor-alpha (TNF-α) was prepared by stimulating macrophage cell line RAW 264.7 with lipopoly-saccharide (LPS) obtained from Escheria coli strain 055:B5.

This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

Neurofibromatosis type two (NF2) is a genetic disorder predisposing those affected to the development of multiple benign tumors in their central and peripheral nervous systems. This is due to the absence of the tumor suppressor protein merlin, which is encoded by the NF2 gene. In nearly all NF2 cases, patients present with bilateral schwannomas of the vestibulocochlear nerve, in addition to other schwannomas throughout the central and peripheral nervous systems, as well as meningiomas and ependymomas. Currently, no therapeutic alternatives to surgical removal and radiation therapy are available for NF2 patients. This study investigated cobimetinib, an inhibitor of the often-deregulated mitogen activated protein kinase (MAPK) pathway in NF2 tumors, and its in vitro mechanism of action in both mouse and human NF2 schwannoma model cell lines. It was demonstrated that the drug decreased 70% and 60% of the viability at 10μM in the mouse and human merlin-deficient cell lines, respectively. It was further demonstrated that this decrease in viability was due to cytostatic and cytotoxic effects of cobimetinib in the case of the mouse NF2 schwannoma model but only due to cytostatic effects of cobimetinib in the human NF2 schwannoma model. These results show promise in targeting the MAPK pathway in NF2 tumors, and the promise of cobimetinib specifically, supporting further cytometric flow and in vivo testing of the inhibitor.

Tumor thrombus in left atrium (LA) is very rare but a serious complication in patients with malignancy. It has a significant impact on clinical decision making, staging and prognosis in oncological patients. Tumor thrombus is seen in a wide variety of malignancies. While rare, lung cancer tumor thrombus may occur. Rarely, it can even extend into LA. Usually, it is managed by surgical resection with chemotherapy. We describe a rare case of tumor thrombus in a patient with squamous cell carcinoma of lung that was managed with chemo- and radiation therapy.

Das Mamma-Karzinom gehört zu den sogenannten desmoplastischen Tumorarten. Hierbei handelt es sich um Tumoren mit erhöhter Ansammlung von Bindegewebszellen und einer Akkumulation von Extrazellulärer Matrix (EZM). Diese verdichtete EZM wirkt sowohl auf mechanischer als auch auf Signalweg-vermittelter Ebene als eine Barriere, welche die therapeutische Wirksamkeit erheblich vermindert. Einer der Hauptbestandteile der EZM ist Kollagen. Durch Anwendung von Präparaten, welche die Kollagensynthese und -reifung inhibieren, kann die rigide Struktur aufgelockert werden. Daraus ergibt sich eine verbesserte Versorgung mit Nährstoffen und eine verbesserte Infiltrationsmöglichkeit für Immunzellen. Dies ist für die Effizienz der Immuntherapie, welche sich in den letzten Jahren als vielversprechende Alternative zu den Grundsäulen der Krebstherapie entwickelt hat, unabdinglich. In der vorliegenden Arbeit wurden murine Mamma-Karzinome der 4T1-Linie nach Behandlung mit EZM-destabilisierenden Kollageninhibitoren auf ihre Immunumgebung hin untersucht. Verwendet wurden drei Wirkstoffe, welche an unterschiedlichen Punkten in die Kollagensynthese und -reifung eingreifen: βAPN als LOX(L)-Inhibitor, 1,4-DPCA als P4HA-Inhibitor und Minoxidil als LH-Inhibitor. Die Behandlung führte zu einem deutlichen Anstieg aller untersuchten Immunzellen und deutet somit auf eine verbesserte Infiltrationsmöglichkeit hin. Zudem wurde die Expression maligner Signalwege, wie die der Angiogenese, Hypoxie, Metastasierungsneigung, Invasivität und Immunsuppression, verringert und tumorsuppressive Immunantworten verstärkt. Die Kollageninhibition hatte zusätzlich ein verringertes Tumorwachstum und eine Reduktion der Blutgefäßdichte zufolge. Als Fazit gilt es festzuhalten, dass die Verwendung von Kollageninhibitoren in der Immuntherapie eine vielversprechende Option zur Verbesserung der Effizienz dieser Therapeutika darstellt. Diese Erkenntnis gilt es im Rahmen künftiger wissenschaftlicher Untersuchungen weiterzuentwickeln. / The mamma carcinoma is a desmoplastic tumor which shows an accumulation of fibrotic tissue and of extracellular matrix (ECM). This highly dense ECM acts as a physical and signaling-mediated barrier reducing the efficacy of various therapeutic approaches. One of the main components of the ECM is collagen. The rigid structure can be loosened by drugs which inhibit collagen synthesis and maturation. This potentially leads to improved infiltration with nutrients and a better access for immune cells. These are absolutely necessary for the effectiveness of the immune therapy that has been established as a promising alternative approach in the last years in addition to the classical cancer therapy options. In this dissertation murine mamma carcinomas of the 4T1-tumor cell line were treated with collagen inhibitors, with the aim to destabilize the rigid ECM and analyze following changes of the immune environment. The drugs, that were used, inhibit at different stages collagen synthesis and maturation: βAPN as a LOX(L)-inhibitor, 1,4-DPCA as a P4HA-inhibitor and Minoxidil as a LH-inhibitor. The treatment led to an accumulation of different kinds of immune cells which shows the improved infiltration. Furthermore, malignant pathways concerning angiogenesis, hypoxia, invasiveness, metastasis, and immunosuppression are reduced. Tumor suppressive immune responses are enhanced. Moreover, we could ascertain a reduced tumor growth and microvessel density after treatment. All in all, the tumors show, because of the changed quantity and constellation of immune cells, a stronger immune stimulating function. This embodies the promising potential of the usage of collagen inhibitors as an additional treatment to immune therapy to facilitate its efficacy, which has to be examined by further studies.

Doctor of Philosophy / Over 1.9 million new cases of cancer will pop up just this year alone. The prevalence of cancer, however, has not been met with the same magnitude of effective treatments, resulting in over 600,000 deaths in the United States. Before current treatments can be improved and new treatments can be developed, it is critical that we increase our understanding of what drives cancer to be so aggressive and maintain a fighting chance within the body despite our complex immune systems. The severity of cancer is not just a product of the cancer cell itself, but rather the components that make up the cell that define and drive metastatic behaviors and drug resistance. In order to improve diagnoses, prognoses, and treatment planning, the intracellular drivers of the disease must be better understood. Cells, electrical circuits in nature, reflect unique electrical properties dictated by their biophysical composition. These electrical properties can be revealed and exploited to characterize and treat contributors to disease progression. Using electric fields applied in several modalities, this work explores the electrical entities of malignant cell types towards improving in vitro treatment planning and developing a treatment modality cognizant of subcellular drivers. This dissertation details the use of dielectrophoresis and electroporation to detect and treat intracellular changes associated with poor prognosis.

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