Synthesis and anti-cancer evaluation of folic acid-peptide- paclitaxel conjugates for addressing drug resistance.

The drug resistance and the poor water solubility are major limitations of paclitaxel (PTX) of based chemotherapy. To conquer the two problems, targeting folate (FA) receptor PTX-lytic peptides conjugates were synthesized and evaluated. Compared with PTX, FA-P3-PTX and FA-P7-PTX displayed significantly enhanced cell toxicity in many cancer cells, particularly drug resistant cancer cells MCF-7/PTX. FA-P7-PTX possessed stronger effect on cell toxicity (IC₅₀ = 2.92 ± 0.2 μM), membrane disrupting activity and pro-apoptosis in MCF-7/PTX cells than FA-P3-PTX. Further investigation displayed that the anti-cancer mechanisms of FA-P3-PTX and FA-P7-PTX might be a mitochondrial impairment and caspase-3-dependent apoptotic cell death. Furthermore, the in vivo antitumor efficacy study confirmed that FA-P7-PTX performed more stronger potency in inhibition of tumors growth than PTX. The study demonstrated that conjugate FA-P7-PTX with superior properties for antineoplastic activity, which makes it a promising potential candidate for drug-resistant cancer therapy.