Fu, Dan, Jing Zhou, Wenjing Suzanne Zhu, Paul W. Manley, Y. Karen Wang, Tami Hood, Andrew Wylie, and X. Sunney Xie. 2014. “Imaging the Intracellular Distribution of Tyrosine Kinase Inhibitors in Living Cells with Quantitative Hyperspectral Stimulated Raman Scattering.” Nature Chem 6 (7) (May 25): 614–622. doi:10.1038/nchem.1961.
ABL1 tyrosine-kinase inhibitors (TKI) are front-line therapy for chronic myelogenous leukaemia and are among the best-known examples of targeted cancer therapeutics. However, the dynamic uptake into cells of TKIs of low molecular weight and their intracellular behaviour is unknown because of the difficulty of observing non-fluorescent small molecules at subcellular resolution. Here we report the direct label-free visualization and quantification of two TKI drugs (imatinib and nilotinib) inside living cells using hyperspectral stimulated Raman scattering imaging. Concentrations of both drugs were enriched over 1,000-fold in lysosomes as a result of their lysosomotropic properties. In addition, low solubility appeared to contribute significantly to the surprisingly large accumulation of nilotinib. We further show that the lysosomal trapping of imatinib was reduced more than tenfold when chloroquine is used simultaneously, which suggests that chloroquine may increase the efficacy of TKIs through lysosome-mediated drug–drug interaction in addition to the commonly proposed autophagy-inhibition mechanism.
oap.needman. Publisher version made dark in DASH; duplicate record withdrawn in DASH, as this was deposited and made live via author's assistant using the manual submission where metadata was incomplete.