title: Monitoring the dynamics of Src activity in response to anti-invasive dasatinib treatment at a subcellular level using dual intravital imaging.
abstract: Optimising response to tyrosine kinase inhibitors in cancer remains an extensive field of research. Intravital imaging is an emerging tool, which can be used in drug discovery to facilitate and fine-tune maximum drug response in live tumors. A greater understanding of intratumoural delivery and pharmacodynamics of a drug can be obtained by imaging drug target-specific fluorescence resonance energy transfer (FRET) biosensors in real time. Here, we outline our recent work using a Src-FRET biosensor as a readout of Src activity to gauge optimal tyrosine kinase inhibition in response to dasatinib treatment regimens in vivo. By simultaneously monitoring both the inhibition of Src using FRET imaging, and the modulation of the surrounding extracellular matrix using second harmonic generation (SHG) imaging, we were able to show enhanced drug penetrance and delivery to live pancreatic tumors. We discuss the implications of this dual intravital imaging approach in the context of altered tumor-stromal interactions, while summarising how this approach could be applied to assess other combination strategies or tyrosine kinase inhibitors in a preclinical setting.
authors.affiliation: a The Beatson Institute for Cancer Research ; Garscube Estate ; Glasgow , UK.
authors.forename: Max
authors.initials: M
authors.lastname: Nobis
authors.forename: Ewan J
authors.initials: EJ
authors.lastname: McGhee
authors.forename: David
authors.initials: D
authors.lastname: Herrmann
authors.forename: Astrid
authors.initials: A
authors.lastname: Magenau
authors.forename: Jennifer P
authors.initials: JP
authors.lastname: Morton
authors.forename: Kurt I
authors.initials: KI
authors.lastname: Anderson
authors.forename: Paul
authors.initials: P
authors.lastname: Timpson
mesh_terms: D015374:Biosensing Techniques; D045744:Cell Line, Tumor; D000069439:Dasatinib; D005109:Extracellular Matrix / Q000187:drug effects* / Q000201:enzymology; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology*; D013844:Thiazoles / Q000494:pharmacology*; D019061:src-Family Kinases / Q000378:metabolism*
chemical_list: D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D013844:Thiazoles; D019061:src-Family Kinases; D000069439:Dasatinib
keywords: ECFP, enhanced cyan fluorescent protein; ECM; ECM, extracellular matrix; FLIM, fluorescent lifetime imaging microscopy; FRET; FRET, fluorescence resonance energy transfer; PDAC, pancreatic ductal adenocarcinoma; RTK, receptor tyrosine kinase; SH2, Src-homology-2; SHG, second harmonic generation; Src; adhesion; in vivo imaging; invasion and metastasis; pharmacodynamics