Aspirin enhances multidrug resistance gene 1 expression in human molt-4 T lymphoma cells

Background: We recently found that aspirin induces the expression of P-glycoprotein (P-gp), a protein mediating drug resistance, in human prostate cancer cells. The purpose of this study was to evaluate the effect of aspirin on the expression of Pgp in a different human cancer type, i.e., T lymphoma. Furthermore, we analyzed this effect at the level of the gene encoding P-gp, MDR1, and of the transcription factor (NF-IL6), regulating this gene. Materials and Methods: NF-IL6 was assayed by the electrophoretic mobility shift assay, MDR1 mRNA was assayed by the reverse transcriptase polymerase chain reaction (RT-PCR), and P-gp was assayed by Western blotting. Results: aspirin, at plasma attainable levels, induced NF-IL6 DNA-binding activity, and increased MDR1 mRNA expression (by up to 140%), as well as the expression of P-gp, in Molt-4 cells. Conclusions: This study suggests that treatment with aspirin induces a cellular signal culminating in the enhancement of P-gp expression in T lymphoma Molt-4 cells.