Establishment and biological characterization of a human glucocorticoid-resistant cell line of diffuse large B cell lymphoma

Abstract

Objective To establish a novel glucocorticoid (GC)-resistant human diffuse large B lymphoma(DLBCL) cell line Toledo/dexamethasone (DEX) by the exposure to DEX,and observe the biological characteristics of resistant and parental cell line,investigate the mechanisms of glucocorticoid-resistance.Methods Toledo/DEX was established by the exposure to DEX,the dose of which was increased gradually and intermittently for long periods of time.Toledo,in the logarithmic growth phage,was incubated in the culture medium containing DEX at the concentration of 1×10-8 mol/L at first.The medium without DEX was replaced after for 96 hours until the cell line re-entered the logarithmic growth phase.Repeat the above steps to acquire the ultimate concentration of DEX in the medium as 1.024 ×10-5 mol/L.The biological characteristics of resistant and parental cell lines were evaluated.Results Toledo/DEX was more invasive in the aspects of ultrastructure,tumorigenicity and drug sensitivity.Meanwhile,Toledo/DEX achieved some stable biological characteristics such as morphology,karyotypes and immunophenotype.Furthermore,GC receptor (GR) α and GR β protein expression analysis showed that GR was involved in the mechanism of the GCresistance.Conclusions Toledo/DEX is a drug-resistant cell line with a stable biology backgroud.These results may help shed light on the knowledge of GC-resistance and lay the groundwork for searching new therapeutics to reverse drug-resistance. Key words: Lymphoma, B-cell; Cell line; Glucocorticoid; Drug-resistance