Gemcitabine anti-proliferative activity significantly enhanced upon conjugation with cell-penetrating peptides

Gemcitabine proven efficiency against a wide range of solid tumors and undergoes deamination to its inactive uridine metabolite, which underlies its low bioavailability, and tumour resistance was also associated with nucleoside transporter alterations. Hence, we have conjugated gemcitabine to cell-penetrating peptides (CPP), in an effort to both mask its aniline moiety and facilitate its delivery into cancer cells. Two CPP-drug conjugates have been synthesized and studied regarding both the time-dependent kinetics of gemcitabine release and their anti-proliferative activity on three different human cancer cell lines. Results obtained reveal a dramatic increase in the anti-proliferative activity of gemcitabine in vitro, upon conjugation with the CPPs. As such, CPP-gemcitabine conjugates emerge as promising leads for cancer therapy.