Life Sciences Commons^™

Protocol For Rapid Assessment Of The Efficacy Of Novel Wnt Inhibitors Using Zebrafish Models, Meghan G. Haney, Mary Wimsett, Chunming Liu, Jessica S. Blackburn

Molecular and Cellular Biochemistry Faculty Publications

Dysregulation of Wnt signaling is a hallmark of many cancers, and the development of effective, non-toxic small-molecule Wnt inhibitors is desirable. Off-target toxicities of new compounds are typically tested in mouse models, which is both costly and time consuming. Here, we present a rapid and inexpensive protocol to determine the in vivo toxicity and efficacy of novel Wnt inhibitors in zebrafish using a combination of a fluorescence reporter assay as well as eye rescue and fin regeneration assays. These experiments are completed within 1 week to rapidly narrow drug candidates before moving to more expensive pre-clinical testing.

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Targeting The Brd4/Foxo3a/Cdk6 Axis Sensitizes Akt Inhibition In Luminal Breast Cancer, Jingyi Liu, Weijie Guo, Zhibing Duan, Lei Zeng, Yadi Wu, Yule Chen, Fang Tai, Yifan Wang, Yiwei Lin, Qiang Zhang, Yanling He, Jiong Deng, Rachel L. Stewart, Chi Wang, Pengnian Charles Lin, Saghi Ghaffari, B. Mark Evers, Suling Liu, Ming-Ming Zhou, Binhua P. Zhou, Jian Shi

Molecular and Cellular Biochemistry Faculty Publications

BRD4 assembles transcriptional machinery at gene super-enhancer regions and governs the expression of genes that are critical for cancer progression. However, it remains unclear whether BRD4-mediated gene transcription is required for tumor cells to develop drug resistance. Our data show that prolonged treatment of luminal breast cancer cells with AKT inhibitors induces FOXO3a dephosphorylation, nuclear translocation, and disrupts its association with SirT6, eventually leading to FOXO3a acetylation as well as BRD4 recognition. Acetylated FOXO3a recognizes the BD2 domain of BRD4, recruits the BRD4/RNAPII complex to the CDK6 gene promoter, and induces its transcription. Pharmacological inhibition of either BRD4/FOXO3a association or …

Tox Regulates Growth, Dna Repair, And Genomic Instability In T-Cell Acute Lymphoblastic Leukemia, Riadh Lobbardi, Jordan Pinder, Barbara Martinez-Pastor, Marina Theodorou, Jessica S. Blackburn, Brian J. Abraham, Yuka Namiki, Marc Mansour, Nouran S. Abdelfattah, Aleksey Molodtsov, Gabriela Alexe, Debra Toiber, Manon De Waard, Esha Jain, Myriam Boukhali, Mattia Lion, Deepak Bhere, Khalid Shah, Alejandro Gutierrez, Kimberly Stegmaier, Lewis B. Silverman, Ruslan I. Sadreyev, John M. Asara, Marjorie A. Oettinger, Wilhelm Haas, A. Thomas Look, Richard A. Young, Raul Mostoslavsky, Graham Dellaire, David M. Langenau

Molecular and Cellular Biochemistry Faculty Publications

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy of thymocytes. Using a transgenic screen in zebrafish, thymocyte selection–associated high mobility group box protein (TOX) was uncovered as a collaborating oncogenic driver that accelerated T-ALL onset by expanding the initiating pool of transformed clones and elevating genomic instability. TOX is highly expressed in a majority of human T-ALL and is required for proliferation and continued xenograft growth in mice. Using a wide array of functional analyses, we uncovered that TOX binds directly to KU70/80 and suppresses recruitment of this complex to DNA breaks to inhibit nonhomologous end joining (NHEJ) repair. …

Pharmacodynamic Assays To Facilitate Preclinical And Clinical Development Of Pre-Mrna Splicing Modulatory Drug Candidates, Yihui Shi, Amanda S. Joyner, William Shadrick, Gustavo Palacios, Chandraiah Lagisetti, Philip M. Potter, Lidia C. Sambucetti, Stefan Stamm, Thomas R. Webb

Molecular and Cellular Biochemistry Faculty Publications

The spliceosome has recently emerged as a new target for cancer chemotherapy and novel antitumor spliceosome targeted agents are under development. Here, we describe two types of novel pharmacodynamic assays that facilitate drug discovery and development of this intriguing class of innovative therapeutics; the first assay is useful for preclinical optimization of small-molecule agents that target the SF3B1 spliceosomal protein in animals, the second assay is an ex vivo validated, gel-based assay for the measurement of drug exposure in human leukocytes. The first assay utilizes a highly specific bioluminescent splicing reporter, based on the skipping of exons 4-11 of a …