Alterations and Mutations in Bruton's Tyrosine Kinase Affect The
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Alterations and mutations in Bruton’s tyrosine kinase affect the transcriptional profile and phenotype of chronic lymphocytic leukemia cells DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Daphne Allyn Guinn Graduate Program in Integrated Biomedical Science Program The Ohio State University 2016 Dissertation Committee: John Byrd, MD, Co-Advisor Amy Johnson, PhD, Co-Advisor Flavia Pichiorri, PhD Albert de la Chapelle, MD, PhD Copyright by Daphne Allyn Guinn 2016 Abstract Chronic Lymphocytic Leukemia (CLL) is currently an incurable disease. The current front-line therapy is chemoimmunotherapy, which is associated with significant toxicity and immunosuppression. Targeted therapeutics have the potential to provide well-tolerated therapies, however the lack of a unifying genetic alteration in CLL has made target identification difficult. Activation of B cell receptor signaling (BCR) is aberrant leading to enhanced pro-survival signaling. An integral kinase in the BCR pathway, Bruton agammaglobulinemia Tyrosine Kinase (BTK) was identified as a viable target in CLL. Targeting BTK with ibrutinib, an irreversible inhibitor, can decrease pro- survival signaling, has significant clinical activity and is now FDA approved. Some patients on long-term ibrutinib therapy acquire a point mutation in ibrutinib’s binding site (BTKC481S). This mutation renders ibrutinib a reversible inhibitor reducing the efficacy of the drug. Determining the transcriptional and phenotypic differences after alteration of BTK is integral for understanding the role of BTK in CLL progression and development of targeted agents to subvert resistance. It is known that ibrutinib targets CLL survival signaling, but it is not known how targeting BTK alters the microRNA (miR) profile. Lymphocytes from ibrutinib treated patients were collected pre- and post-therapy and were analyzed by miR Nanostring. A unique profile of differentially expressed miRs was identified. OncomiR, miR-155 was confirmed to be down-modulated with ibrutinib therapy. Analysis of miR-155 expression ii was done on responding versus relapse patients on long-term ibrutinib therapy. miR-155 expression remained down-modulated in responding patients, but was elevated in relapsed patients. We conclude that miR-155 can be favorably down-modulated by ibrutinib treatment and may play a role in resistance. Another novel miR identified was tumor suppressive, miR-126. In our studies, we show that miR-126 is reduced with CLL disease progression. miR-126 expression is negatively correlated with levels of p85β, a regulatory subunit of PI3K complex, in CLL patients and in miR-126 overexpression cells lines. This study identified a novel miR and its role in targeting PI3K complex in CLL. The development of the BTKC481S ibrutinib resistant mutation is associated with shorter patient survival after relapse. To study the growth advantage the resistant clone provides, B lymphocyte cell lines that are lacking BTK were obtained and BTKWT and BTKC481S were expressed. Infection with BTKC481S rendered the cells ibrutinib resistant. The BTKC481S shows enhanced kinase activity, migration, pro-survival signaling and increased levels of immune modulatory molecules. After engraftment of BTKWT and BTKC481S cell lines into NSG mice, the mice who received mutant cells had a shorter median survival. Overall we see BTKC481S significantly alters the phenotype of the cells leading to survival of the resistant clone. In conclusion, this work demonstrates that targeting BTK with ibrutinib can alter the miR profile of the CLL cells, identifying miR-155 and miR-126 as having a role in CLL disease biology. We have also shown that cells that acquire the BTKC481S mutation have enhanced activity and can accelerate disease progression. Overall we can conclude iii that alterations to BTK through pharmacological inhibition or mutation can affect the CLL disease phenotype. iv Dedication To my wonderfully supportive family and friends v Acknowledgments First I would like to thank my mentor Dr. John Byrd. You are an inspiration every day. The passion you have for you patients, science and life is an inspiration. Thank you for asking the hard questions and constantly striving to achieve your best. I greatly appreciated the way you can look at negative data and find the silver lining. Thank you for you high standard of ethical conduct in the laboratory and in clinic. The constant reminder that our research is impactful and could lead to clinical breakthroughs is a driving force for me every day. Finally thank you for seeing something in me and investing your time to mold me into the scientist I am today. To my co-mentor, Dr. Amy Johnson, you are an amazing woman and you lead by example. Thank you for you direct, but constructive mentorship style. I initially wanted you as a mentor because of your honesty and the fantastic projects you had to offer. The science was not always easy and you made sure to make time to help me through the difficult experiments. Thank you for all the weekly meetings of talking science and sharing your wisdom. I hope to be as successful as you at solving new scientific problems and enjoying life. I also want to thank my committee members, Drs. Flavia Pichiorri and Albert de la Chapelle for your time, thoughtful questions and guidance through my graduate school experience. Thank you to Drs. Jennifer Woyach, Erin Hertlein, David Lucas and Yuh-Ying Yeh, for your advice and mentorship over the years, having so many brilliant scientists around really vi made the laboratory a fun and innovatively environment. I would also like to thank all the Byrd lab members, each one of you has played an important role in my growth as a scientist. First to Derek West, thank you for all that you do, I cannot begin to list the number of things you have done for me over the years, but I greatly appreciate it all. To the Byrd lab technicians, especially Lisa Smith, Frank Frissora, Katie Williams, Arletta Lozanski, Carolyn Cheney, and Shelley Orwick, who gave such great advice and help. To the undergraduate students that I had the pleasure to mentor, Ben Whitfield and Catherine Fabian, thanks for your optimism and hard work, being your mentor was so rewarding and fun. To all the Byrd lab graduate students thanks for support and sharing in the gratifying experience that is getting a PhD, journal club, lab meeting, and the occasional happy hour. Especially to Priscilla Do, Cecelia Miller, and Tim Chen, thank you for your friendship, the lunchtime talks, experiment advice and all the adventures. To my IBGP friends and their significant others, Brynn Hollingsworth, Chris Buettner, Jacque Corry and JC Regan, I am so happy that I had the opportunity to meet and get to know you. You have been amazing friends and I wish you all the best of luck, as you move on as well. Thank you to my family in-law, Joe, Karla, and Sam. I couldn’t have married into a more loving and supportive family. To my siblings and niece and nephew, you helped mold me into the woman I am today with all your humor and love. To my parents, Chuck and Beth Guinn, you are the two best parents a girl could have. Thank you for teaching me the value of hard work and perseverance. You have made me the women I am today with your love, faith and support. I love you so much and you make me proud every day to call you my parents. To my amazing and super supportive husband, I couldn’t have done vii this without you. Thank you for your patience and love. You have been with me every step of the way, keeping me company during long nights of studying, driving me to work on late nights and weekends, and providing me words of support when I needed them the most. I cannot wait to see where our next step in life takes us. Finally I would like to thank all the CLL patients that consented to provide samples as part of clinical trials at OSU. Without your help, this work would not have been possible. viii Vita December 7, 1988 ....................................Born, Columbus, OH May 2011 .................................................B.S. Toxicology/Biology, Ashland University July 2011 to present ................................Graduate Research Associate, Biomedical Science Graduate Program, The Ohio State University Publications Guinn D, Lehman A, Yu L, Maddocks K, Jaglowski S, Woyach J, Byrd JC, and Johnson AJ. The regulation of tumor suppressive microRNA, miR-126, in chronic lymphocytic leukemia. In preparation Woyach JA*, Guinn D*, Ruppert AS, Lehman A, Blachly JS, Lozanski A, et al. Resistance to ibrutinib in Chronic Lymphocytic Leukemia is due to mutations in BTK and PLCG2 that are associated with an aggressive disease phenotype and poor outcomes. In preparation. Hing ZA, Mantel R, Beckwith KA, Guinn D, Williams E, Smith LL, Williams K, Johnson AJ, Lehman AM, Byrd JC, Woyach JA, Lapalombella R. (2015) Selinexor is effective in acquired resistance to ibrutinib and synergizes with ibrutinib in chronic lymphocytic leukemia. Blood 125: 3128-3132. Guinn D, Ruppert AS, Maddocks K, Jaglowski S, Gordon A, Lin TS, Larson R, Marcucci G, Hertlein E, Woyach J, Johnson AJ, and Byrd JC. (2015). miR-155 expression is associated with chemoimmunotherapy outcome and is modulated by Bruton’s tyrosine kinase inhibition with Ibrutinib. Leukemia 29:1210-1213. Dong S, Guinn D, Dubovsky JA, Zhong Y, Lehman A, Kutok J, Woyach JA, Byrd JC, Johnson AJ. (2014). IPI-145 antagonizes intrinsic and extrinsic survival signals in chronic lymphocytic leukemia cells. Blood 124: 3583-3586. ix Fields of Study Major Field: Integrated Biomedical Science Program Area of Research Emphasis: Experimental Therapeutics, Chronic Lymphocytic Leukemia, microRNAs, Kinase inhibitors, B cell receptor signaling x Table of Contents Abstract ............................................................................................................................... ii Dedication ..........................................................................................................................