Glioblastoma is a deadly and debilitating disease. Lacking effective treatment modalities, it has a 10- year mortality of nearly 100%. In order to understand this complex and highly heterogeneous tumor, it is critical that we develop tools that can measure individual cell populations within it. The Candidate proposes the use of ribosome profiling to identify the translational landscape within specific cellular populations of a murine RiboTag glioma model which recapitulates the human proneural glioma subtype. By molecularly dissecting the tumor through IP of markers associated with transformed cells and normoxic conditions, we can identify alterations in translation across multiple cellular subpopulations. Furthermore, by utilizing pRPS6 as a marker, we can shed light on this translationally important downstream effector of the mTOR pathway. In short, we aim 1) to identify phopsho-RPS6- associated transcripts in different cellular contexts and determine the impact of RPS6 phosphorylation on ribosome positioning and translation in cultured cells, 2) to dissect the normoxic and hypoxic populations of transformed cells in glioma tissue and determine the key pathways and potential therapeutic targets that differentiate them using ribosome profiling. These experiments will not only shed light on an important signaling molecule involved in neural development, invasion, proliferation, and metastasis, but could potentially uncover novel therapeutic targets and lead to enhanced treatments for this disease.
A particular issue in the treatment and study of glioma is the high level of cellular heterogeneity found within. By utilizing a method which will allow for signa and cell-type specific selection, this project will allow significant gains to be made in understanding the translational activity of specific populations within glioma as well as the translational effects of a critical molecule in a pathway essential for tumor proliferation and invasion. This understanding may ultimately allow for new therapies and treatment paradigms to be developed in order to combat this insidious and deadly disease.
|Gonzalez, Christian; Sims, Jennifer S; Hornstein, Nicholas et al. (2014) Ribosome profiling reveals a cell-type-specific translational landscape in brain tumors. J Neurosci 34:10924-36|