Antiproliferative activity of papaverine in human GBM U87MG and T98G cells.

(A) Chemical structure of papaverine. (B) Protein levels of MGMT, RAGE, and GAPDH analyzed by immunoblotting. GAPDH used as an internal control. Data are representative of at least three independent experiments. (C) T98G cells treated with 10 μg/mL bovine HMGB1 protein or vehicle (PBS) and then incubated for 72 h. Cells were counted by trypan blue dye exclusion assay using the TC20 automated cell count system. Cell proliferation (%) represents the mean ± SE of three independent experiments. P values were calculated against vehicle control with the Student’s t-test. **p < 0.05, **p < 0.01. (D) The migration ability of T98G cells was analyzed in an in vitro scratch assay. T98G cells were treated with papaverine at the indicated concentration or water as a vehicle for 24 h. The migration ratio (%) represents the mean ± SE of triplicate experiments. Similar results were obtained in two independent experiments. P values were calculated against vehicle control with the Student’s t-test. *p < 0.05, **p < 0.01. (E) U87MG and (F) T98G cells were examined for cell activity in a WST-8 assay after 72 h papaverine treatment. Results are the averages of three independent experiments with error bars showing SE from triplicates.