Cancer, an often incurable and progressively disabling condition, is frequently characterized by mutations caused by chromosomal rearrangements. However, many of these mutations are poorly understood, and consequently, the availability of novel therapeutic regimens is limited. The molecular targets of Myc, a transcription factor whose oncogene has been marked as one of the most highly amplified oncogenes in many human cancers, has mystified scientists for decades. Due to the difficulty of using targeted therapies to limit Myc oncogene addition, recent studies have explored the concept of non-oncogene addiction through synthetic lethality to identify Myc's oncogenic support pathways. Specifically, large-scale RNA interference (RNAi) screening was used to successfully identify unique genes that are synthetically lethal in Myc-transformed cells, namely the core spliceosomal factors. Although these were landmark findings, it remains unclear if MYC overexpression is maintained solely by the spliceosome or if other RNA-binding proteins (RBPs) are responsible for detrimental changes in splicing patterns in these cells. This project involves using leading edge technologies to perform large-scale functional assays to identify RBPs that control Myc-dependent survival in cancer. CRISPR/Cas9 screens have been used in the past to overcome many RNAi limitations, and have since been used in various successful genome-scale screens. This proposal will employ a targeted CRISPR screen to identify a common set of RBPs specifically required for survival of both Myc-transformed human mammary epithelial cells and patient-derived cancer cells characterized by elevated MYC levels. Technologies including eCLIP-seq and RNA-seq will be used to identify the physical and functional targets of one candidate RBP. This study will provide feasibility to broadly explore the function of RBPs in many human cancers, which will undoubtedly improve the current understanding of miregulations in the human genome that lead to this devastating disease. Lastly, this study will develop a novel genomic tool extendable to other biological questions, while accelerating cancer genome research by providing a set of synthetic lethal RBPs in various Myc-induced tumor-specific cell lines as clinical validation for targeting RBPs as treatment.!
Cancer is a progressively disabling condition that is often characterized by the accelerated division of abnormal cells due to the amplification of the Myc oncogene. This work aims to explore the function of RNA-binding proteins that are required for Myc-dependent cancer cells to initiate and maintain their oncogenic state using cutting edge technologies including eCLIP-seq, RNA-seq, and large-scale CRISPR-Cas9 screens. This study will provide a novel genomic tool that can be readily extended to other biological questions, as well as provide RNA-binding protein binding and splicing data in relevant cancer types that may identify novel therapeutic targets for this large class of cancers.