Perturbations in epidermal homeostasis result in a wide variety of human skin diseases, including cancer. To identify regulators of epidermal growth and differentiation that are disrupted in skin cancer, I performed exome and RNA sequencing of cutaneous squamous cell carcinomas (SCC). Recurrent abnormalities were detected in 4 major categories of protein-coding genes, including receptor tyrosine kinase (RTK)-Ras-MAPK pathway genes, Notch regulators, chromatin remodelers, and members of the Mediator complex. Also identified were 11 entirely new and previously unannotated SCC Misregulated Transcripts (SMRTs) that are putative long noncoding RNAs (lncRNAs) with consistent aberrant expression in SCC. This K08 application proposes to characterize the role of these protein-coding and noncoding genes during normal epidermal growth and differentiation as well as early tumor progression. I will begin by characterizing the impact of skin cancer-associated protein-coding gene mutations on epidermal homeostasis and early tumor progression, focusing on novel members of each category found to be mutated at high frequency in SCC. Human epidermal tissue with SCC-associated genetic alterations will be generated and analyzed. Combinations of genetic alterations arising in spontaneous SCC will also be introduced into epidermal tissue to test the hypothesis that simultaneously targeting RTK-Ras-MAPK signaling, Notch pathway regulators, chromatin remodelers, and the Mediator complex diverts homeostatic gene expression towards neoplastic conversion. Next, I will define the role of each of the 11 novel SMRT genes in skin homeostasis and early tumorigenesis by generating and characterizing human epidermal tissue with loss or gain of SMRT expression. Of note, the first functional studies of any SMRT indicate that SMRT-2 is required for epidermal differentiation. Using SMRT-2 as a prototype, functionally active SMRTs will be analyzed using recently developed high-throughput methodologies to identify their physical interactions with protein, RNA, and DNA biomolecules. Such interactions can provide important initial mechanistic insight and suggest avenues for deeper exploration. Over the course of the proposed training period, I hope to uncover new protein-coding and noncoding regulators of skin homeostasis with impacts on early tumorigenesis and begin characterizing their mechanisms of action. These findings may form the foundation of future treatment strategies for disorders characterized by disrupted epidermal homeostasis, such as skin cancer. My immediate goal in seeking a K08 award is to continue my training as a physician-scientist while building independence as an investigator. I am interested in understanding how perturbations in key homeostatic processes lead to human disease as the foundation for new therapies. The studies proposed in this K08 application are designed to provide an enhanced understanding of the mechanisms that govern epidermal differentiation and growth while using insight gleaned from these efforts to inform a deeper exploration of the mechanisms of neoplastic progression. While my graduate and early postdoctoral work has largely provided me with the scientific skill set needed to perform these studies, the training period supported by this K08 award will supply new expertise in epithelial and cancer biology as well as additional experience using human tissue models to study epidermal homeostasis and neoplasia. Through continued intensive mentoring and strong collaborations with Stanford leaders in gene regulation, RNA biology, computational genomics, and bioinformatics, I will also develop vital proficiency in new high-throughput approaches designed to provide unbiased mechanistic insight. I ultimately envision myself leading an independent and productive laboratory that makes meaningful contributions to epithelial biology as well as academic dermatology while actively encouraging students and fellows to pursue their own careers in science. The studies proposed in this K08 application will allow me to shed valuable insight on new mechanisms governing epidermal differentiation and growth as well as clarify how their disruptions lead to cancer. At the same time, these efforts wil help me establish an independent line of research distinct from my mentor and collaborators'areas of interest. The new scientific directions and questions that arise from this work, along with the enhanced academic and scientific skill set developed during the training period, will form the basis for my own independent laboratory.
A delicate balance between cell growth and differentiation is required to maintain the health of tissues. Disturbing this balance in human skin results in a variety of diseases, including chronic wounds, psoriasis, and cancer. This proposal focuses on characterizing the role of disrupted or dysregulated cancer-associated genes in skin homeostasis.
|Lee, Carolyn S; Bhaduri, Aparna; Mah, Angela et al. (2014) Recurrent point mutations in the kinetochore gene KNSTRN in cutaneous squamous cell carcinoma. Nat Genet 46:1060-2|