Triptolide Inhibits PCa Cells Proliferation Figure 4. Triptolide down-regulated SENP1 expression in PCa cells. (A) Triptolide decreased SENP1 mRNA level in both LNCaP and PC-3 cells in a dose-dependent manner. Cells were treated with indicated doses of Triptolide or Celastrol for 24 h before analysis. qRT-PCR were performed using the specific primers for SENP1 and b-actin (used as an internal control). (B) Triptolide decreased SENP1 mRNA level in both LNCaP and PC-3 cells PLoS ONE | www.plosone.org 7 May 2012 | Volume 7 | Issue 5 | e37693