Tumor Biology, Development, Stem Cells, Hematopoiesis, Immune Function
In vivo and in vitro models of hematopoiesis, transformation and immunity, retroviral transduction, bone marrow transplantation, ES cell culture and differentiation, cDNA cloning, cell sorting, video microscopy, knockout and RNAi technology, ChIP-Seq and global transcription analysis
Description of Research
A major area of interest of this laboratory is understanding the processes that lead to the development and differentiation of mature hematopoietic cells from a single hematopoietic stem cell. We are particularly interested in studying the processes that perturb these normal processes and cause leukemia. A primary focus of the laboratory is the role that Notch proteins play in regulating hematopoietic cell fate decisions and cancer. Notch proteins are a conserved family of receptors that regulate cell fate decisions in organisms ranging from Drosophila to humans. Using a variety of in vitro and in vivo approaches, we have shown that Notch proteins are key regulators of multiple hematopoietic cell fates. These include establishment of the T cell lineage and helper type 2 T cells. We are presently undertaking studies to identify the signaling pathways that control these and other cell fate decisions in hematopoiesis. In addition to their role in normal hematopoiesis, dysregulation of Notch signaling is a cause of human leukemia. We have developed a mouse model of Notch-related leukemia and are using this to study the signaling pathways that lead to oncogenic transformation. Using gene array and bioinformatics approaches, we have identified several direct transcriptional targets of Notch signaling that appear to mediate its effects in normal development and leukemia. In addition, we are developing and testing ways to block Notch signaling that may be useful in treating leukemia and other Notch-dependent diseases.
1. Characterization of Notch transcriptional targets in hematopoiesis and leukemia. This project will characterize potential direct transcriptional targets of Notch signaling that we have identified in a microarray screen. The project will involve verifying that these are direct transcriptional targets using chromatin immunoprecipitation (ChIP), EMSA, and reporter assays and then testing whether these targets are functionally important using retroviral transduction, apoptosis, proliferation, and differentiation in both primary and established cell lines.
2. Identification of genes that potentiate Notch transforming activity. We have induced a number of Notch T cell leukemias using retroviruses that express activated forms of Notch1. The retroviral vectors also contain enhancer elements that can activate transcription of genes in the vicinity of their integration site. We have established techniques to rapidly clone the genes that are activated by retroviral vector integration and will use both in vitro and in vivo assays to determine if they synergize with Notch to induce leukemia.
3. We have identified Tribbles as a novel oncogene in acute myelogenous leukemia. Very little is know about Tribbles function. This project will use biochemical and functional assays to determine the function of Tribbles in leukemia and normal hematopoietic development.
Katherine Forsyth, Graduate Student
Ethan Mack, Graduate Student
Vicki Mercado, Post-baccalaureate Scholar
Caitlin O'Neill, Administrative Assistant
Yumi Ohtani, Senior Research Investigator
Jelena Petrovic, Postdoctoral Fellow
Kelly Rome, Graduate Student
Sarah Stein, Postdoctoral Fellow
Lanwei Xu, Research Specialist/Lab Manager
Kong G, You X, Wen Z, Chang Y-I, Qian S, Ranheim E.A, Letson C, Zhang X, ZY, Liu Y, Rajagopalan A, Zhang J, Stieglitz E, Loh M, Hofmann I, Yang D, Zhong X, Padron E, Zhou L, Pear W.S., Zhang J: Downregulating Notch counteracts Kras-induced ERK activation and oxidative phosphorylation in myeloproliferative neoplasm. Leukemia Sep 2018.
Johnson JL, Georgakilas G, Petrovic J, Kurachi M, Cai S, Harly C, Pear WS, Bhandoola A, Wherry EJ, Vahedi G: Lineage-determining transcription factor TCF-1 initiates the epigenetic identity of T cells. Immunity 48: 243-257, 2018.
Maillard, IM and Pear, WS: Can genetics resolve what Notch does in HSCs. Blood 2018 Notes: accepted for publication, Feb 2018.
Russell JHR, Petrovic J, Rausch DM, Zhou Y., Lareau C, Kluk, MJ, Christie AL, Lee L, Tarjan D, Guo B, Donohue LKH, Gillespie S, Nardi V, Hochberg EP, Blacklow SC, Weinstock DM, Faryabi RB, Bernstein BE, Aster JC, and Pear WS: A B-cell regulome links Notch to downstream oncogenic pathways in small B-cell lymphomas. Cell Reports 21: 784-797, 2017 Notes: Accepted for publication (September 2017).
Severson E, Arnett KL, Wang H, Zang C, Taing L, Liu H, Pear WS, Liu XS, Blacklow SC, Aster JC: Genome-wide identification and characterization of Notch transcription complex-binding sequence-paired sites in leukemia cells. Science signaling 10(477), May 2017 Notes: No page number issued.
Plikus MV, Guerrero-Juarez CF, Ito M, Li YR, Dedhia PH, Zheng Y, Shao M, Gay DL, Ramos R, His TC, Oh JW, Wang X, Ramirez A, Konopelski SE, Elzein A, Wang A, Supapannachart RJ, Lee HL, Lim CH, Nace A, Guo A, Treffeisen E, Andl T, Ramirez RN, Murad R, Offermanns S, Metzger D, Chambon P, Widgerow AD, Tuan TL, Mortazavi A, Gupta RK, Hamilton BA, Millar SE, Seale P, Pear WS, Lazar MA, Cotsarelis G: Regeneration of fat cells from myofibroblasts during wound healing. Science 355(6326): 748-752, Feb 2017.
Aster JC, Pear WS, Blacklow SC: The Varied Roles of Notch in Cancer. Annual review of pathology 12: 245-275, Jan 2017.
Pajcini KV, Xu L, Shao L, Petrovic J, Palasiewicz K, Ohtani Y, Bailis W, Lee C, Wertheim GB, Rajeswaran M, Musuthamy N, Li Y, Meijerink JPP, Blacklow SC, Faryabi RB, Cherry S and Pear WS: MafB is a novel enhancer of oncogenic Notch signaling in T-cell acute lymphoblastic leukemia. Science Signaling 10, 2017 Notes: Sci Signal. 2017 Nov 14;10(505). pii: eaam6846. doi: 10.1126/scisignal.aam6846.
Kobayashi M, Nabinger S, Bai Y, Yoshimoto M, Gao R, Chen S, Yao C, Dong Y, Zhang L, Rodriguez S, Yashiro-Ohtani Y, Pear WS, Carlesso N, Yoder MC, Kapur R, Kaplan MH, Lacorazza HD, Zhang ZY, Liu Y: Protein Tyrosine Phosphatase PRL2 Mediates Notch and Kit Signals In Early T Cell Progenitors. Stem cells 35(4): 1053-1064, Dec 2016.
Chiang MY, Wang Q, Gormley AC, Stein SJ, Xu L, Shestova O, Aster JC, Pear WS: High selective pressure for Notch1 mutations that induce Myc in T-cell acute lymphoblastic leukemia. Blood 128(18): 2229-2240, Nov 2016.
back to top
Last updated: 12/07/2018
The Trustees of the University of Pennsylvania