Figure 4. FILIP1L is induced by TOP2 poisons but not by catalytic inhibitors.

(A) U2OS cells were treated with DMSO (Control), the TOP2 poisons doxorubicin (200 ng/ml), etoposide and mitoxantrone, or the TOP2 catalytic inhibitors merbarone or dexrazoxane. After 24 hours of treatment, mRNA was harvested from cells and FILIP1L expression levels were measured by qPCR analysis. (B) To allay concern that chosen drug dosages of the TOP2 inhibitors was too low to affect FILIP1L expression, we measured % cell viability after drug treatment. Treated cells were harvested after 24 hours and cell viability was measured using an Invitrogen Countess automated cell counter.