Human cells transcribe tens of thousands of long non-coding RNAs (lncRNAs) ? transcripts > 200 nucleotides in length which are not translated into protein. Certain lncRNAs regulate important cellular functions and contribute to the development of human neurological diseases including brain cancers, such as glioblastoma multiforme (GBM). Given that expression of lncRNAs is highly specific to certain cancers, lncRNAs are attractive therapeutic targets. However, few lncRNAs have been studied as potential therapeutic targets in GBM which is the most common primary malignant brain cancer. Despite surgery, chemotherapy and radiation, median survival remains 14-16 months in patients with GBM, and new treatment strategies are needed. My long-term goal as a future neurosurgeon-scientist is to develop novel GBM therapies that improve patient clinical outcomes. In pursuit of this goal, my immediate objective is to determine the role of specific lncRNAs in GBM tumor growth and investigate their potential utility as therapeutic targets. My mentor's laboratory has recently used CRISPR interference (CRISPRi) as a knockdown method to screen thousands of different human lncRNAs in parallel to identify those that are required for proliferation of GBM cancer cells. As shown in Preliminary Studies, one particular lncRNA called LINC00909 is a promising therapeutic target. CRISPRi-mediated knockdown of LINC00909 strongly reduced glioma cell growth in culture, as well as in a GBM xenograft mouse model. LINC00909 overexpression is highly specific to gliomas, and higher LINC00909 expression predicts shorter survival of patients with mesenchymal-type GBM. Given these findings, my overall hypothesis is that specific lncRNAs such as LINC00909 are required for the growth of GBM tumors and may serve as targets for the development of novel adjuvant therapies to slow tumor growth and extend survival in GBM. In the proposed research, my first Aim will determine the role of LINC00909 in GBM cell propagation and determine whether knockdown of LINC00909 will slow GBM cell growth alone or in combination with the current standard-of-care chemotherapeutic temozolomide.
My second Aim addresses a critical barrier to translating lncRNA knockdown into a clinical therapy and will investigate whether local delivery of anti-sense oligonucleotides targeting lncRNAs, such as LINC00909, within brain tumors of GBM xenografts is a viable therapeutic strategy in the brain. Completion of these studies will make important advances in the development of lncRNA-targeted therapy in human GBM. In addition, it will provide me with valuable mentored-training in areas I lack expertise to continue my development as a physician-scientist and better prepare me to become an independent investigator.
Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor and has a poor prognosis (median survival: 14-16 months). Human cells transcribe tens of thousands of long non-coding RNAs (lncRNAs), and emerging research has identified specific lncRNAs unique to GBM which are important for tumor growth. This work will investigate a previously unstudied lncRNA as a novel treatment in GBM.