The NIH K08 mentored career development award provides the necessary foundation for me to fulfill my long-term career goals of being an independently-funded translational investigator focusing on the therapeutic manipulation of autophagy in the treatment of cancer. The mentored award will also help me achieve my immediate goals of obtaining expertise both in autophagy research and in the management of non- melanoma skin cancer. Under the auspices of the University of Texas Southwestern Medical Center at Dallas, I hope to attain these objectives through the following: 1) career mentorship from internationally recognized physicians and scientists who are experts in autophagy, dermatology, and cancer biology, 2) specific guidance in the form of structured reading and courses, which I will apply to experiments and patient care. My mentored research project centers on a novel model for the regulation of autophagy by Akt and keratin intermediate filaments and tests this model for its effects on tumorigenesis;our model challenges the current paradigm that the regulation of autophagy occurs primarily through mTOR. Addressing the question of how autophagy is regulated will be essential not only for interpreting the results of ongoing clinical trials but also for improving the way autophagy is manipulated in future cancer therapies.
Aim 1 tests our hypothesis that Akt and phosphorylation of Beclin 1 directly regulate autophagy. First, we will test our hypothesis that Akt can regulate autophagy independently of mTOR through phosphorylation of Beclin 1. Next, we will determine how the status of PI3K-Akt activation in cancer cells affects the phosphorylation of Beclin 1. Finally, we will address what effects the phosphorylation of Beclin 1 has on autophagy and cell proliferation in cancer cell lines.
Aim 2 will test whether the phosphorylation of epithelial keratins regulates autophagy in vitro and whether known pathogenic keratin mutations affect autophagy and cell proliferation. First, mutant intermediate filament (IF) proteins and cells deficient for specific IFs cells will b tested for their effects on autophagy in established in vitro assays. Next, we will determine whether this inhibition of autophagy results in excess cell proliferation in vitro. Finally, we wil use mouse models with keratin defects (both deletions and mutations) to test whether impaired autophagy contributes to keratinopathies and tumorigenesis.
Aim 3 will test what effects the disruption of the predicted complex has on tumorigenesis in in vitro assays and in vivo mouse models. The effects of IF mutations on tumorigenesis will be determined in vitro. Next, we will test whether the chemical induction of autophagy or genetic induction of autophagy through disruption of proposed regulatory complex can prevent tumorigenesis in vivo. These studies will employ an established model of non-melanoma skin cancer formation in skin with an inducible deletion of PTEN. These studies will transform our current understanding of how autophagy is regulated and impact how autophagy is manipulated to treat cancer in future clinical trials.
This project seeks to confirm and extend preliminary findings that a novel pathway that involves a known oncogene (Akt) directly regulates autophagy and tumorigenesis. A better understanding of this pathway will have an immediate impact on how results of ongoing clinical trials, which seek to inhibit autophagy to treat cancer, are understood In addition, the reagents and findings generated by these studies may improve the manipulation of autophagy in future cancer therapies.