Figure 5.

Monitoring cellular uptake of active puromycin in live cancer cells treated with the prodrug. (A) Illustration of the method to monitor the prodrug activation in live cancer cells using flow cytometry. Cancer cells with increased HDAC and CTSL activities can selectively unmask the prodrug releasing active puromycin which in turn rapidly end-labels newly synthesized proteins, while the prodrug is inactive in normal cells. (B) HCT116 cells were untreated or treated either with Boc-Lys(Ac)-Puromycin (Boc-KAc-Puro), Fmoc-Lys(Ac)-Puromycin (Fmoc-KAc-Puro) or puromycin (Puro) for 20 h, followed by antibody staining and flow cytometry analysis.