Tumor cycling hypoxia induces chemoresistance in glioblastoma multiforme by upregulating the expression and function of ABCB1.

ABSTRACT: Tumor cycling hypoxia is now a well-recognized phenomenon in animal and human solid tumors. However, how tumor cycling hypoxia impacts chemotherapy is unclear. In the present study, we explored the impact and the mechanism of cycling hypoxia on tumor microenvironment-mediated chemoresistance. Hoechst 33342 staining and hypoxia-inducible factor-1 (HIF-1) activation labeling together with immunofluorescence imaging and fluorescence-activated cell sorting were used to isolate hypoxic tumor subpopulations from human glioblastoma xenografts. ABCB1 expression, P-glycoprotein function, and chemosensitivity in tumor cells derived from human glioblastoma xenografts or in vitro cycling hypoxic stress-treated glioblastoma cells were determined using Western blot analysis, drug accumulation and efflux

SUBMITTER: Chou CW 

PROVIDER: S-EPMC3452342 | biostudies-literature | 2012 Oct

REPOSITORIES: biostudies-literature