Chemotherapeutical Agent Triggers Transient Resistance Of Cancer Cells By Promoting Abcb1 Intercellular Transfer

Multidrug resistance remains a major impediment to successful chemotherapy. In clinical chemotherapy, some patients often develop chemoresistance quite rapidly, the underlying mechanism remains elusive. Herein, we report that a transient exposure to chemotherapeutic agents can acutely promote the intercellular transfer of ABCB1 through stimulating Rab8B-mediated secretion of microvesicles (MVs) containing ABCB1 in drug-resistant donor cells, and promoting parallelly the endocytic recycling of ABCB1 in recipient tumor cells via the downregulation of Rab5. Sensitive recipient cells take up these ABCB1-incorporated MVs by a clathrin- and dynamin 2- dependent endocytic pathway, thereby acquiring a transient resistance to chemotherapeutic agents which are ABCB1 substrates. More fascinatingly, ABCB1 molecules can locally or distantly transfer to recipient tumor cells and respond to chemotherapeutical drug in the xenograft tumor models. In some cases of patients with NSCLC, a variable increase of ABCB1 surface expression was also detected in the peripheral blood monocyte subpopulations after they received the first chemotherapy. Our findings proposed a novel molecular mechanism of how sensitive cancer cells rapidly acquire the emergency resistance to chemotherapeutic agents by stimulating intercellular transfer of ABCB1. The precise modulation of this process may provide a valid therapeutic strategy to alleviate the MDR phenotype for successful treatment. Citation Format: Xiaokun Wang, Dongjuan Qiao, Likun Chen, Liyan Huang, Meng Xu, Zhen Chen, Fang Wang, Zhesheng Chen, Musheng Zeng, Li-Wu Fu. Chemotherapeutical agent triggers transient resistance of cancer cells by promoting ABCB1 intercellular transfer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3180. doi:10.1158/1538-7445.AM2017-3180