HA regulates expression of ATP binding cassette (ABC) drug transporters. A. ABCB3. B. ABCC4. C. ABCC1. D. ABCC2. E. ABCC3 &F. BCL21. Ovarian cancer cells treated with HA (5 μg/ml) for 72 hr. OVCAR-5 cells also treated in presence or absence of HA oligomers (HYA oligo, 250 μg/ml). Relative gene expression was determined by calibration against no HA control and normalized to the house keeping gene β-actin using the 2-∆∆CT method following 72 hr HA treatment. Data represents mean ± SEM from 2–4 independent experiments performed in triplicate following. *, significantly different from no HA control (P < 0.05, independent t test). C = no HA (control medium), HA = hyaluronan (5 μg/ml).