ABCG2-overexpressing S1-M1-80 cell xenografts in nude mice keep original biochemistry and cell biological properties

摘要

S1-M1-80 cells,derived from human colon carcinoma S1 cells,are mitoxantrone-selected ABCG2-overexpressing cells and are widely used in in vitro studies of multidrug resistance(MDR).In this study,S1-M1-80 cell xenografts were established to investigate whether the MDR phenotype and cell biological properties were maintained in vivo.Our results showed that the proliferation,cell cycle,and ABCG2 expression level in S1-M1-80 cells were similar to those in cells isolated from S1-M1-80 cell xenografts(named xS1-M1-80 cells).Consistently,xS1-M1-80 cells exhibited high levels of resistance to ABCG2 substrates such as mitoxantrone and topotecan,but remained sensitive to the non-ABCG2 substrate cisplatin.Furthermore,the specific ABCG2 inhibitor Ko143 potently sensitized xS1-M1-80 cells to mitoxantrone and topotecan.These results suggest that S1-M1-80 cell xenografts in nude mice retain their original cytological characteristics at 9 weeks.Thus,this model could serve as a good system for further investigation of ABCG2-mediated MDR.