Figure 5.

Chk1 regulates nSMase2 transcriptionally. (a and b) MCF7 cells were seeded in 60 mm dishes and were pretreated with the specified inhibitor 1 h before stimulation with either vehicle or doxorubicin. Twenty-four hours after treatment, cells were collected and immunoblotted for nSMase2 and actin (a), or RNA was isolated and transformed to cDNA and quantitative real-time PCR (qRT-PCR) was performed for nSMase2 (b), *P<0.05. (c and d) MCF7 cells were seeded in 60 mm dishes and siRNA was performed using AllStars Negative Control (AS), Chk1, Chk2 or Chk1+Chk2. After 24 h, cells were stimulated with either vehicle or doxorubicin and collected for analysis by immunoblotting (c) or qRT-PCR (d), *P<0.05