Influence of extracellular vesicles on invasion of primary glioblastoma
A) Purpose of the Experiment : Glioblastoma (GBM) is the most aggressive primary brain tumor. Invasive tumor cells escape current treatment strategies and lead to tumor recurrence. It has been shown that extracellular vesicles, exosomes in particular, which are derived of late endosomes are important for cell communication and function. We have observed in in vitro and in vivo experiments, that some glioblastoma stem cells (GSCs) lines show non-invasive properties. However, using an ex-vivo organoid co-culture system, we have shown that when non-invasive cell lines are primed with exosomes from invasive GSC lines (BG5, BG7, GG16, P3XX), they obtain invasive capacities. In this project, we will need to verify these experiments in vivo. We will use non invasive GSCs for implantation into the brain of nude rats together with exosomes obtained from invasive cell lines. The cells will be modified for expression of luciferase for bioluminescence imaging. We will determine if the non-invasive GG6 cells becomes invasive after orthotopic implantation into the brains of nude rats. The animals will be followed up by bioluminescence and MRI imaging. The experiment will provide insight into the role of extracellular vesicles in modulating the behaviour of stromal cells into an invasive phenotype.
B) Expected Distress for animals : We will implant brain tumor cells into the brains of nude rats. Tumors will develop and imaged regularly by MRI. From extensive prior experience, these surgical procedures are well tolerated by the animals. When tumors reach a size of 125mm3 as verified by MRI, the animals will be euthanized, and the tumors will be removed for further analysis. Based on prior experience, and due to the fact that the animals will be euthanised before symptoms related to tumor burden appear, there should be a minor animal distress.
C) Expected Scientific or societal benefit : GBM is a highly aggressive tumor of the brain with dismal prognosis. Basic understanding of resistance mechanisms and development of new treatment strategies are needed to improve the survival of these patients.
D) Number of animals : 180 and Type : Nude Rats
E) Replacement, reduction and improvement : We have already performed extensive experiments in the cell culture using an ex-vivo organdie system. In order to evaluate a future therapeutic potential, we need to perform an in vivo experiments. In addition tumor cell invasion is highly dependent on the tumor microenvironment which is very complex and cannot be fully mimicked in vitro.
I vår opprinnelige søknad var dette prosjektet planlagt å være ferdig 02.05.2021. På grunn av korona-situasjonen har vi i dette prosjektet kun brukt 20 dyr. Prosjektet er ikke ferdigstilt.
Vi søker derfor om å fornye prosjektet slik at ferdigstillelse vil være 31.12. 2022.
B) Expected Distress for animals : We will implant brain tumor cells into the brains of nude rats. Tumors will develop and imaged regularly by MRI. From extensive prior experience, these surgical procedures are well tolerated by the animals. When tumors reach a size of 125mm3 as verified by MRI, the animals will be euthanized, and the tumors will be removed for further analysis. Based on prior experience, and due to the fact that the animals will be euthanised before symptoms related to tumor burden appear, there should be a minor animal distress.
C) Expected Scientific or societal benefit : GBM is a highly aggressive tumor of the brain with dismal prognosis. Basic understanding of resistance mechanisms and development of new treatment strategies are needed to improve the survival of these patients.
D) Number of animals : 180 and Type : Nude Rats
E) Replacement, reduction and improvement : We have already performed extensive experiments in the cell culture using an ex-vivo organdie system. In order to evaluate a future therapeutic potential, we need to perform an in vivo experiments. In addition tumor cell invasion is highly dependent on the tumor microenvironment which is very complex and cannot be fully mimicked in vitro.
I vår opprinnelige søknad var dette prosjektet planlagt å være ferdig 02.05.2021. På grunn av korona-situasjonen har vi i dette prosjektet kun brukt 20 dyr. Prosjektet er ikke ferdigstilt.
Vi søker derfor om å fornye prosjektet slik at ferdigstillelse vil være 31.12. 2022.