The proposed study is to explore novel therapeutic opportunities to cure malignant gliomas by perturbing telomere maintenance mechanisms in glioma stem cells. Malignant gliomas are highly resistant to treatment largely due to the existence of glioma stem cells (GSCs), which possess inexhaustible ability to self-renew and proliferate. I propose to target GSCs by inhibiting telomerase because GSCs have higher level of telomerase activity than somatic cells and other non-GSC tumor cells.
With Aim 1, I will explore GSCs'response to telomerase inhibition with three independent model systems. I will also test whether anti-telomerase sensitizes conventional radiation therapy and chemotherapy in combinatorial therapy regimens. My previous study showed that anti-telomerase will lead to resistance through ALT (Alternative Lengthening of Telomeres) mechanisms, so in Aim 2 I will generate and characterize GSCs that rely on ALT mechanisms and will explore the possibility to target the weakness of ALT in order to prevent the resistance in response to anti-telomerase therapy. More evidence is pointing to the important function of chromatin remodeling factors in the regulation of telomeres, so in Aim 3, I will investigate the mechanisms of telomeric chromatin remodeling in telomerase+ and ALT+ glioma stem cells. The information obtained from this aim will help us understand the natures of ALT mechanisms in the GSC context and provide new therapeutic opportunities to target ALT+ GSCs. This proposed study will help me to form a strong research program, with which I will launch an independent faculty position in an academic/medical research institution. To that end, my immediate goals are to continue sharpening my technical skills in mouse genetics, telomere biology and stem cell biology and expanding my skills in oncogenomics, biostatistics and translational biology. In terms of my career development, I will be devoted to improve my skills on managing lab, mentoring postdocs and students, scientific writing and presentation, and seeking for collaborations, among others, because these skills are all essential for me to land a faculty position and succeed as a PI. MD Anderson Cancer Center (MDACC) and the Ronald DePinho laboratory provide an excellent training environment for me to achieve these goals. Even though Dr. DePinho is President of MDACC now, he still promises to devote 2.5% effort to my training and career development. I have also formed an extraordinary advisory committee composed of Dr. Mien-Chie Huang, Dr. Wai-Kwan Yung and Dr. Junjie Chen. They will not only provide me technical support for my proposed study, but also guide me to look for a faculty position and succeed as an independent investigator. With the help of K99/R00 training grant, I will have a good start to achieve my long term goals, which are to continue exploring basic and translational problems in cancer biology, including telomere biology and cancer stem cell biology, as a lab head in an academic/medical research institute and to contribute in developing novel cancer therapies as a team player by collaborating with other scientists, physicians and pharmaceutical companies.
Killing glioma stem cells provides a novel therapeutic opportunity to cure malignant glioma, the most common and lethal type of brain tumor in adults. One of the hallmarks of glioma stem cells is high activity of telomerase, an enzyme complex responsible for maintaining telomere sequences at ends of chromosomes. The proposed study is to explore the novel therapeutic approaches by inhibiting telomerase and the possible resistant mechanisms resulting from these therapies.
|Shingu, Takashi; Ho, Allen L; Yuan, Liang et al. (2017) Qki deficiency maintains stemness of glioma stem cells in suboptimal environment by downregulating endolysosomal degradation. Nat Genet 49:75-86|
|Zhang, Peng; He, Dandan; Xu, Yi et al. (2017) Genome-wide identification and differential analysis of translational initiation. Nat Commun 8:1749|
|Shingu, Takashi; Jaskelioff, Mariela; Yuan, Liang et al. (2015) Utilizing murine inducible telomerase alleles in the studies of tissue degeneration/regeneration and cancer. J Vis Exp :|