Quantitative proteomic analysis to the first commercialized liposomal paclitaxel nano-platform Lipusu revealed the molecular mechanism of the enhanced anti-tumor effect.

The first nano-platform commercialized as a drug delivery system was a liposomal formulation. The application of liposome technology resolved the issues of paclitaxel (PTX) insolubility and eliminated the use of solvents causing toxic side-effects, which enabled to apply higher drug doses leading to an enhanced drug efficacy. The growth-inhibitory activity of liposome-encapsulated PTX was retained in vitro against a variety of tumor cell. To investigate the drug efficacy in the system biological level, quantitative proteomic analysis was employed to study the molecular mechanism of the anti-tumor effect of Lipusu® (lip) compared with PTX on lung cancer cell A549. The functions of the differential expressed proteins were correlated to the negative effect to cell proliferation due to regulation of hippo pathway and prolonged cell cycle, as well as inhibitory cell exocytosis, which would cause the aggregation of free PTX. This investigation focused on the direct biological effect of lip to cancer cells. It was different from pharmaceutical issues about drug exposure, delivery and distribution which were widely investigated in other traditional studies. It was the first study about the drug effect of lip from the global molecular biological aspect.