OBJECTIVETo establish bortezomib (BOR)-resistant human multiple myeloma U266 cell line U266/BOR and to detect its biological characteristics.

METHODSU266 cells were constantly exposed at low dose and progressively increasing dose of BOR to establish U266/BOR, the cell morphology was observed by inverted microscopy, ICand resistant index were determined by MTT assay, cell growth curve was drawed and the doubling time was calculated; cell cycle distribution were analyzed by flow cytometry, and RT-PCR was used to detect the mRNA expression of resistance-related genes.

RESULTSThe MM U266/BOR cell line was successfully constructed and its resistance index was up to 19.8. The both cell morphologies were not different. Compared with U266 cells, the multiplication time was postponed with the increase of G/Gcell ratio, and S phase was reduced. The mRNA expression of PTPROt, Beclin 1 and PTEN were reduced, and the mRNA expression of c-Maf was enhanced in U266/BOR cells; as compared with U266 cells, but the MDR1 mRNA expression was not different between U266 cells and U266 BOR cells.

CONCLUSIONThe BOR-resistant U266 cell line has been establiseed successfully. It provides an ideal cell model for further exploration of the mechanism for BOR resistance.