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Small Molecule Probes for in vivo Imaging of Protease Function Overview O HN O N H • Why Activity is Important Biotin H N O O O H N N H O OH O X O X= Arg, Leu, Asp, Asn, Gly • Activity Based Probes (ABPs) – What are they? – How do they work? • Applications of ABPs – Biochemical profiling • Caspases - Alicia Berger - Mol. Cell. 2006, 23:509-521 – Imaging • Cathepsins - Galia Blum – Chemical Genetics • Protease function in human parasites Carolyn Phillips, Shirin Kapur – Toxoplasma gondii – Plasmodium falciparum Activity Based Probes for Proteases O R O H N H N N H O R N H R O R O Peptide Substrate O Tag R O H N RFG N H O R Activity Based Probe Activity Based Probes for Proteases O Tag R O O H N O N H O R -S R Tag O R O H N N H O Enz R S Enz AOMK Cat K Cat F Cat C Cruzain Cat H Cat S Cat L Papain Cat V Cat B The qABP GB11 GB111 GB17 GB117 Quenched Probe Strategy Imaging in Live Cell Monolayers GB111 GB111 + JPM LysoTracker LysoTracker + JPM LysoTracker LysoTracker + JPM Merge Merge Merge GB117 Merge GB117 + JPM Blum et al. Nature Chemical Biology, 2005, 1, 203-209 Stability of Probes GB111 Serum (Hrs): Inhibitor: – – – + 1 4 – – GB117 – – – + 1 4 – – GB136 – – – + 1 4 – – 97 66 42 36 Cat B Cat L Cat L 28 20 Non quenched Quenched Quenched Cathepsins and Cancer • Cathepsins have been linked to cancer progression – Cathepsin B - mainly in cell culture models • Recently more complex mouse models have been tested – RIP-Tag - Joyce et al. (2004) Cancer Cell, 5, 443-453 – PyMT - study with cat B -/- mice - Vasiljeva et al. (2006) Cancer Research, 66, 5242 – Angiogenesis model - Cathepsin L - Urbich et al. (2005) Nature Medicine, 22, 206-213. – RIP-Tag/ Cat K/O - Joyce et al. (2006) Genes and Development, 20, 543 • All support a role for cathepsins in tumor growth and angiogenesis – Protease activity provided by tumor microenvironment not just tumor cells Multistage tumorigenesis in RIP-Tag transgenic mice Normal stage (onc+) Hyperplastic/ Dysplastic stage Angiogenic stage Tumor stage <4 wks 4-7 wks 5-12 wks 10-14 wks 100% ~50% ~10% 2-4% Cathepsin activity profiling in vivo Exocrine pancreas Normal islet Normal islet x200 Fluorescent cathepsin probe Fluor cathepsin probe/DAPI Exocrine pancreas Tumor x100 Joyce et al. Cancer Cell (2004) 5, 443-53. Tumor Need for NIRF probes NIRF Probe and Control N N N HN N O HN H N O O O O O N H O O H N O O GB123 O N H NH2 O GB125 Georges von Degenfeld Galia Blum Cathepsin Activity in Tumor Cell Lines C2C12 par C2C12 ras U87MG ذ + ذ + ذ + MCF-7 MDA MB-435 MDA MB-231 ذ + ذ + ذ + 98 * 66 42 36 28 20 14 Ex/Em 633/670 In vivo Imaging of Cathpsins Baseline 2 hr 4 hr 8 hr 10 hr 12 hr 24 hr 500 450 MDA-MB# 435 231 X106 400 350 p/sec/cm 2 Baseline MDA-MB# 231 435 2 hr 8 hr 12 hr 24 hr In vivo Imaging of Cathpsins GB123 Baseline 4.0 0.5 hr 5 hr Signal to Noise 23 hr 4 3.6 3 2 3.2 GB123 1 0 0 MDA MB231 MFP 3.0 GB138 25 GB138 0 5 10 15 20 Hours after injection 1.0 GB123 GB125 20 2 1 0 1.5 1 min 15 3 2.0 MDA-MB-231 Before injection 10 7 6 5 4 2.5 MDA MB231 MFP 5 5h 22 h 25 Need for NIRF probes Probe: 123 125 123 123 - + acat B a cat L Tumor Origin: MDA-MB 23 C2C12/ras Local DMSO: 97 97 66 42 36 36 28 cat B 28 cat L 20 20 Ex/Em 633/670 In Vivo Images 66 42 Ex/Em 633/670 Imaging Drug Efficacy Ki777 AMS28 Vehicle Ki777 AMS28 Ki777 Vehicle AMS28 1.0 0.9 0.7 x109 0.8 0.6 0.5 Base line 30 minutes 8 hours Tumor Fluorescence Ki777 Vehicle 9.0 4.0 8.0 5.0 4 hours Ki777 12 3.5 3.0 AMS28 8.0 2.5 2.0 1.5 4.0 Vehicle 0.0 Ki777 Vehicle 1.0 x109 6.0 x109 7.0 p/sec/cm2/srX109 16 Quantification of Drug Efficacy Tumor Kidney Liver Conclusions • Activity based probes can be used to monitor protease ACTIVITY in complex proteomes • Quenched activity based probes allow real time imaging of protease activation • Near Infrared fluorescent probes can be used to monitor protease activity in live animals – Potential applications • Diagnostic imaging - fluorescent, PET • Pharmacodynamic studies • Drug efficacy studies Acknowledgements The Bogyo Lab Galia Blum Shirin Arastu-Kapur Alicia Berger Carolyn Phillips Beth Ponder Galia Blum Daisuke Kato Steven Verhelst Kelly Sexton Marko Fonovic Alicia Berger Carolyn Phillips Shirin Arastu-Kapur Masoud Sagadhiani Fang Yuan Beth Ponder Mark Rice NIMR Mill Hill Mike Blackman Sharon Yeoh Stanford Georges von Degenfeld Helen Blau The Burnham Guy Salvesen Jean Bernard Denalt Sloane Kettering Johanna Joyce UCSF Doug Hanahan Jessica Pahler Compound Libraries James Powers Bill Rousch UVM Gary Ward Jeralyn Haraldsen Funding http://bogyolab.stanford.edu Department of Defense - BCCOE, Sandler Family, Searle Scholars Fellowship, NIH Roadmaps NTCNP Grant, Burroughs Wellcome Fund, NIH PPG