David Andrews

Administrative Assistant: Michael Le
T: (416) 480-6100, ext. 85482
Email: michael.le@sri.utoronto.ca

At A Glance

• Cancer research: programmed cell death, apoptosis, Bcl-2 family proteins, drug development, and personalized medicine
• Membrane biogenesis research: protein-protein interactions, assembly of proteins into membranes, tail-anchored proteins
• Technology Development: New automated microscopes for Fluorescence Lifetime Imaging Microscopy (FLIM), Forster Resonance Energy Transfer (FRET) and hyperspectral imaging. New software for automated image analysis, image-based high-content cellular analysis
• Commercialization: Collaborations with multiple pharmaceutical companies and started two biotech spin-off companies
• Patents: Translational regulation, in-vitro evolution and peptide display technologies

Short Bio

Dr. David Andrews is Director of and Senior Scientist in Biological Sciences at Sunnybrook Research Institute (SRI). He holds a Tier 1 Canada Research Chair in Membrane Biogenesis. His research comprises, the molecular mechanisms by which Bcl-2 family proteins regulate apoptosis, early stage drug discovery, high-content screening and development of new microscopes for fluorescence lifetime imaging microscopy (FLIM) and hyperspectral imaging. Dr. Andrews’ lab uses fluorescence spectroscopy and fluorescence spectroscopic microscopy to study interactions between proteins in membranes using purified proteins, and in live cells. To study cancer, they use primary patient cells grown as 3D organoids for drug screening. At SRI, he has established a facility for image-based high-content cellular analysis that includes instrumentation for automated imaging and analysis of cells in monolayer and 3D cultures, genome scale gene knockdown and screening of libraries of small molecules. In early stage drug discovery research, his lab has identified and characterized small molecules that have applications to cancer and regenerative medicine.

Dr. Andrews is active in the public and private sector. He is a member of several editorial boards, including BMC Molecular and Cell Biology and Cell Death and Differentiation. His lab has collaborated with a number of pharmaceutical companies including Abbott, ABBVIE, Celgene, Eli Lilly, Genentech, Johnson and Johnson, and Novartis. Dr. Andrews is developing a new generation of automated high-speed hyperspectral FLIM confocal and new AI driven software for automated analysis of fluorescence micrographs of cells. FLIM is used to measure protein-protein interactions in live cells. Automated microscopy and machine learning tools are being applied to develop new personalized medicine approaches for diseases including chronic lymphocytic leukemia, ovarian cancer and breast cancer.

View Dr. David Andrews' ORCID Profile.

Research Synopsis

Regulation of apoptosis by Bcl-2 family proteins.
The Bcl-2 family proteins primarily responsible for drug responses (and the lack thereof) include: i) the anti-apoptotic proteins: Bcl-2, Bcl-XL and Mcl-1, ii) the pro-apoptotic executioner proteins Bax and Bak and iii) the pro-apoptotic regulator BH3-proteins Bid, Bim, Bad, Bik, Puma and Noxa. Our “embedded together” model for how Bcl-2 family proteins regulate mitochondrial permeabilization (MOMP) dominates the field. It shifted attention from unidirectional interactions to dynamic equilibria involving conformational changes induced by binding to membranes. It also introduced the concept of mutual sequestration to explain the biological outcomes resulting from Bcl-2 family protein interactions. Our model has been tested and validated by many independent labs using different experimental strategies. Our 2008 paper in Cell resolved a major controversy by showing that tBid binds to and activates Bax only after both proteins bind membranes. In 2012 in Mol. Cell we reported confirmation of many of the predicted interactions in live cells using FLIM FRET and quantified several important differences in live cells compared to previous in vitro data. In 2020 we showed that the protein-protein interactions between Bcl-XL molecules bound to Bcl-2 family proteins result in allosteric regulation of cell death. We also identified new binding interactions between Bim and Bcl-XL and between Bim and Bax that we characterized in vitro and in live cells.

Chemical biology of Bcl-2 family proteins and drug responses in cells.
To provide the impetus for translation of our results to benefit patients, we are identifying small molecule inhibitors of pro- and anti-apoptotic proteins. These probes permit us to demonstrate to pharmaceutical companies that the targets we identify are pharmaceutically tractable. Using high throughput screening, we identified small molecules that target protein-protein interaction sites for Bcl-2 family proteins, thereby providing validation directly relevant to pharma. One class of molecules is currently being assessed for full drug development. In preclinical experiments, these molecules selectively kill human and murine derived tumours in mice. We are also using high content screening techniques and primary cell cultures of patient cells to identify small molecules targeting Bcl-2 family proteins that elicit apoptosis selectively in cancer cells of individual patients for personalized medicine applications. In contrast, small molecule inhibitors of pro-apoptotic Bcl-2 family proteins inhibit cell death and are being developed for cell based therapies and for treating degenerative diseases. For cell based therapies, our goal is to improve the survival of precious cells during implantation. For degenerative diseases, such as ALS, preventing cell death over the long term is key.

Quantifying protein-protein interactions in live cells.
Because of the importance of protein-protein interactions in discovery, translational and pharmaceutical research, many methods and instruments have been developed to detect these interactions. However, quantifying protein-protein interactions in live cells remains one of the most difficult tasks in cell biology. To solve this problem, we pioneered the use of fluorescence lifetime imaging microscopy fluorescence resonance energy transfer (FLIM FRET). We have used FLIM FRET to examine protein-protein interactions for Bcl-2 family proteins and how these can (and cannot) be modulated by small molecules. FLIM FRET also enabled quantification of an interaction between hexokinase II and PEA-15 that regulates the response of neurons to changes in oxygen and metabolism. To enable measurement of binding constants in live cells we had to improve the hardware and software for FLIM FRET. We use these innovations in our own research and to help pharmaceutical companies with their drug development programs.

Development of new AI based approaches for measuring cellular responses to drugs in cancer organoids.
Our results highlighted the need for new high content screening approaches to determine how cancer cells respond to drugs. To generate quantitative data, we record fluorescence intensity images for cells in 3D organoids in culture. This approach generates terabytes of data per experiment and required the development of new faster AI based methods for analysis. We are currently testing these methods for rapid 3D phenotypic analysis in companion studies for clinical trials.

Recent Publications

• Leber B, Kale J, Andrews DW. Unleashing Blocked Apoptosis in Cancer Cells: New MCL1 Inhibitors Find Their Groove. Cancer Discov. 2018 Dec;8(12):1511-1514. 
• Liu Q, Osterlund EJ, Chi X, Pogmore J, Leber B, Andrews DW. Bim escapes displacement by BH3-mimetic anti-cancer drugs by double-bolt locking both Bcl-XL and Bcl-2. Elife. 2019 Mar 12;8:e37689. 
• Hickman KA, Hariharan S, De Melo J, Ylanko J, Lustig LC, Penn LZ, Andrews DW. Image-Based Analysis of Protein Stability. Cytometry A. 2020 Apr;97(4):363-377. 
• Bogner C, Kale J, Pogmore J, Chi X, Shamas-Din A, Fradin C, Leber B, Andrews DW. Allosteric Regulation of BH3 Proteins in Bcl-xL Complexes Enables Switch-like Activation of Bax. Mol Cell. 2020 Feb 20;77(4):901-912.e9.
• Schormann W, Hariharan S, Andrews DW. A reference library for assigning protein subcellular localizations by image-based machine learning. J Cell Biol. 2020 Mar 2;219(3):e201904090. 
• Hirmiz N, Tsikouras A, Osterlund EJ, Richards M, Andrews DW, Fang Q. Highly Multiplexed Confocal Fluorescence Lifetime Microscope Designed for Screening Applications. IEEE Journal of Selected Topics in Quantum Electronics. 2020.
• Longo J, Smirnov P, Li Z, Branchard E, van Leeuwen JE, Licht JD, Haibe-Kains B, Andrews DW, Keats JJ, Pugh TJ, Trudel S, Penn LZ. The mevalonate pathway is an actionable vulnerability of t(4;14)-positive multiple myeloma. Leukemia. 2021 Mar;35(3):796-808.
• Vervloessem T, Sasi BK, Xerxa E, Karamanou S, Kale J, La Rovere RM, Chakraborty S, Sneyers F, Vogler M, Economou A, Laurenti L, Andrews DW, Efremov DG, Bultynck G. BDA-366, a putative Bcl-2 BH4 domain antagonist, induces apoptosis independently of Bcl-2 in a variety of cancer cell models. Cell Death Dis. 2020 Sep 17;11(9):769.
• Pemberton JM, Pogmore JP, Andrews DW. Neuronal cell life, death, and axonal degeneration as regulated by the BCL-2 family proteins. Cell Death Differ. 2021 Jan;28(1):108-122.
• Mergenthaler P, Hariharan S, Pemberton JM, Lourenco C, Penn LZ, Andrews DW. Rapid 3D phenotypic analysis of neurons and organoids using data-driven cell segmentation-free machine learning. PLoS Comput Biol. 2021 Feb 22;17(2):e1008630.
• Lv F, Qi F, Zhang Z, Wen M, Kale J, Piai A, Du L, Wang S, Zhou L, Yang Y, Wu B, Liu Z, Del Rosario J, Pogmore J, Chou JJ, Andrews DW, Lin J, OuYang B. An amphipathic Bax core dimer forms part of the apoptotic pore wall in the mitochondrial membrane. EMBO J. 2021 Jul 15;40(14):e106438.
• Pogmore JP, Uehling D, Andrews DW. Pharmacological Targeting of Executioner Proteins: Controlling Life and Death. J Med Chem. 2021 May 13;64(9):5276-5290.

Graduate Students

Yin Ting Sherry Chen 
Dang Nguyen