Functional Interrogation of Genetically Simple and Complex Cancers
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FUNCTIONAL INTERROGATION OF GENETICALLY SIMPLE AND COMPLEX CANCERS by Edward R. Kastenhuber A Dissertation Presented to the Faculty of the Louis V. Gerstner, Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy New York, NY December, 2018 ___________________ ___________________ Scott W. Lowe Date Dissertation Mentor Copyright ©2018 by Edward Kastenhuber Dedication To my parents, for all their love and support. iii ABSTRACT The rapid expansion of cancer genomics over recent years has provided a valuable catalog of the events that drive malignancy, but functional dissection of oncogenes and tumor suppressor genes are needed to fully appreciate the roles of cancer-associated genes. Cancer types vary dramatically in genomic complexity, with pediatric cancers tending towards low mutation rates and certain other diseases tending towards hypermutation and highly rearranged genomes. Targeting driving oncogenes for therapy has precedent, particularly in low complexity cancers, and pre-clinical models provide an opportunity to refine such strategies. Treating high complexity tumors remains particularly challenging in part due to intratumoral heterogeneity, presumed to be linked to enhanced adaptability of cancer cell populations. Patterns of evolution supporting intratumoral heterogeneity have been extensively observed, but functional dissection of heterogeneity has been limited. Fibrolamellar hepatocellular carcinoma (FL-HCC) is a rare but lethal liver cancer that primarily affects adolescents and young adults. It has been described to harbor only one recurrent genetic event: somatic deletion of a segment of chromosome 19, resulting in DNAJB1-PRKACA gene fusion. Efforts to understand and treat FL-HCC have been confounded by a lack of models that accurately reflect the genetics and biology of the disease. Herein, CRISPR/Cas9 genome editing and transposon-mediated somatic gene transfer is implemented to demonstrate that expression of both the endogenous fusion protein or chimeric cDNA leads to the formation of indolent liver tumors in mice that closely resemble human FL-HCC. Notably, overexpression of the wild type PRKACA iv was unable to fully recapitulate the oncogenic activity of DNAJB1-PRKACA, implying that FL-HCC does not result from enhanced PRKACA expression alone. Tumorigenesis was significantly enhanced by genetic activation of β-catenin, an observation supported by the discovery of recurrent Wnt pathway mutations in human FL-HCC, as well as treatment with hepatotoxin DDC, which causes tissue injury, inflammation and fibrosis. Our study validates the DNAJB1-PRKACA fusion kinase as an oncogenic driver and candidate drug target for FL-HCC and establishes a practical model for preclinical studies to identify strategies to treat this disease. In contrast, many cancers do not contain a single identifiable driver. Instead, evolutionary processes govern cancer initiation, metastasis, and therapeutic resistance. A better understanding how initiating driver events affect intratumoral heterogeneity, and how diversity affects the robustness of a population, is central to understand the evolution. Our hypothesis is that p53 deficiency tends to permit the accumulation of greater subclonal diversity than in p53 wild type cancer cell populations. TP53, the most frequently mutated gene in human cancer, is activated by various stress stimuli and acts to cull damaged cells. By using derivatives of the Eµ-myc model of B-cell lymphoma, we examined how p53 inactivation affects the heterogeneity of resulting disease. We aim to resolve whether p53 loss allows the outgrowth of a single aneuploid “jackpot” clone, or does it allow the long-term survival of a wider field of sub-optimally fit clones, which could serve a diverse reservoir of potential resistance to changing conditions, as in dissemination and treatment? v BIOGRAPHICAL SKETCH Edward Kastenhuber grew up in Newtown, Pennsylvania and attended the University of Pittsburgh, where he graduated with a degree in bioengineering. He enjoyed a number of research experiences in engineering and medicine. With Gregory Armstrong (Children’s Hospital of Philadelphia), he explored the epidemiology of optic nerve gliomas arising in children with neurofibromatosis. With Yong He and Sanjeev Shroff, he studied how mechanical stress can influence gene expression and endothelial cell behavior in the context of high blood pressure. Under the direction of Mark Gartner, Edward joined a senior design project team that designed, prototyped and installed an ultra-low cost neonatal incubator for Hôpital Albert Schweitzer Haiti. After reading about cancer immunotherapy for glioblastoma in the university newspaper, Edward was inspired by the work of Hideho Okada and knew he wanted to become involved in this work. Dr. Okada accepted Edward into his lab as a technician where postdocs Ryo Ueda, Xinmei Xhu, and especially Mitsugu Fujita contributed greatly appreciated mentoring. It was here that Edward really got to know the joy of scientific investigation and the culture of the laboratory. Having taken a minor concentration in Italian studies during his undergraduate studies, Edward found an exciting and rewarding opportunity working in S. Aureus vaccine development for Novartis in Siena, Italy for which he is indebted to Fabio Bagnoli for his mentorship. Upon returning to the United States, Edward was hired as a research technician by Jason Huse as he was starting up his lab focused on molecular profiling and pathogenesis vi of glioma. Dr. Huse provided Edward a great deal of independence and responsibility while bringing the lab from empty benches to a productive scientific endeavor. Along with the generous support by Cameron Brennan to learn the R programming language and incorporate more data analysis into his work, Edward published a first author paper with the Huse lab. In 2011, Edward was accepted by the Gerstner Sloan Kettering Graduate School and joined the laboratory of Scott Lowe the following year. He has been supported by the Geoffrey Beene Foundation and the NIH Ruth L. Kirschstein National Research Service Award. vii ACKNOWLEDGEMENTS I thank my thesis mentor Scott Lowe for his leadership, advice, and support. He has led by example through his accomplished career, the extraordinarily enriching environment he has cultivated, and the resources to do the best possible science. He has challenged me to always pursue a standard of excellence driven by curiosity, yet he provided me with an uncommon level of independence. He has opened many doors for me: by inviting me to the p53 workshop (Singapore), the AACR general meeting (Chicago, IL), and an HHMI Science Meeting (Bethesda, MD); by introducing me to countless amazing scientists; and by initiating exciting collaborations with other labs. I am deeply indebted to members of the Lowe lab: Direna Alonso-Curbelo (for her enthusiasm and ideas), Pancho Barriga, Timour Baslan, Lynn Boss, Matt Bott, May Chalarca, Katerina Chatzi (an excellent lab neighbor, friend and advisor), Chi-Chao Chen (for sharing the entire Lowe lab PhD experience together), Sean Chen, Ray Ho, Shauna Houlihan (for indispensible advice including a key experiment with DDC), Amanda Kim, Josef Leibold (with whom I have enjoying sharing a bench and brainstorming over the years), Mei-Ling Li, Grace Xiang Li, Eva Loizou (for her support and sharing the Lowe lab PhD experience together), Riccardo Mezzadra, Wei Luan, Scott Millman, Paul Romesser, Stella Paffenholz, Marcus Ruscetti, Francisco Sanchez-Rivera (for his limitless generosity and sage advice), Janelle Simon, Anahi Tehuitzil, Sha Tian, Kaloyan Tsanov, Corina Amor Vegas, Leah Zamechek, and Zhen Zhao. And also former lab members that have already moved on: Sarah Ackerman, Erica Anderson, Iris Appelmann, Ana Banito, Benedikt Bosbach, Chong Chen, Luke Dow, Saya Ebbesen (for viii incorporating me into the lab), Danielle Grace, Chun-Hao Huang, Thomas Kitzing, Kiki Liu (for teaching me about lymphoma), Geulah Livshits, Amaia Lujambio (for teaching me about liver cancer), Eusebio (Chebi) Manchado (for being an excellent benchmate), Allison Mayle, Ozlem Mert, Cornelius Meithing, Kevin O’Rourke, Cory Rillahan, Anna Saborowski, Michael Saborowski, Adi Shroff, Nilgun Tasdemir, Merri Taylor, Darjus Tschaharganeh (for teaching me about liver cancer), and Susi Weissmuller. I appreciate the consistent insight that I have been fortunate to receive from my thesis committee members Timothy Chan and Charles Sawyers. I have always been impressed by how broad their knowledge base extends and have always been inspired by their enthusiasm and encouragement. I would especially like to thank collaborators Gadi Lalazar and Sanford Simon, Linas Mazutis, Roshan Sharma and Dana Pe’er, J. Erby Wilkinson, Nitin Shirole and Rafaella Sordella, Carol Prives, Neal Rosen, Luke Dow, and Ghassan Abou Alfa. I would also like to thank some of the other people that have taken the time to teach me something, provide me with useful tools and methods, to edit my work, to help brainstorm, and to generally help me enjoy the last few years. Thanks to Charles Sherr (for his advice, stories, and tough questions), Yadira Soto-Feliciano, Viraj Sangvi, Robert Bowman, Yilong Zou, Joana DeCampos Vidigal, Andrea Ventura, Johanna Joyce, Leila Akkari, Oakley Olson, Alberto Schumacher, Dan Marks, Robert Benezra, Zhirong Bao, Steve Albanese, Manu Vanaerschot, Maria Skamagki, Javier Carmona.