Abraxane, the Nanoparticle Formulation of Paclitaxel can Induce Drug Resistance by Up-regulation of P-gp

Abraxane, a nanoparticle (NP) formulation of paclitaxel (PTX), has been demonstrated to be more effective than Taxol, the small molecule formulation, for the treatment of breast cancer and non-small cell lung cancer (NSCLC). It was reported that Abraxane existed in plasma as particles with the size of ~10 nm. NPs get in and out of the cells by endocytosis and exocytosis, whereas small molecules by diffusion and efflux. It is intriguing to know whether the improved pharmaceutical performance is related to the “too-big-to-be-pumped-out” phenomenon. Here we established an Abraxane-resistant NSCLC cell line A549/Abr and compared its transcriptomes with that of the Abraxane-sensitive parental cell line by RNA-Seq technology. To our surprise, the most significantly up-regulated genes were ABC transporters, the common efflux pump for small molecules. We further found that the ABCB1 inhibitor Verapamil reversed the drug resistance and confirmed the important role of ABCB1 in Abraxane resistance. Overall design: mRNA profiles of A549 and A549/Abr cells were generated using Illumina Hiseq 2000 and compared.

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Zhao M, Lei C, Yang Y, Bu X, Ma H, Gong H, Liu J, Fang X, Hu Z, Fang Q