The effect of cisplatin on ARNT expression.

<p>(A) HeLa cells were treated with cisplatin for 24 h. Total RNA was extracted for reverse-transcription PCR with ARNT and GAPDH primers. (B) HeLa cells were treated with 10 µM MG132 or 1 µM lactacystin for 4 h followed by cisplatin for 36 h. Expression of ARNT and actin were analyzed by Western blotting analysis using anti-ARNT and anti-actin antibodies. (C) HeLa and HeLaR cells were treated with various concentrations of taxol and doxorubicin for 24 h. Expressions of ARNT and actin were detected by Western blotting analysis using anti-ARNT and anti-actin antibodies. (D) After 30 µM cisplatin treatment of HeLa and HeLa R cells, apoptotic DNA fragmentation was determined as described in "<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099242#s4" target="_blank">Materials and methods</a>". (E) Cells were transfected with 30 nM ARNT siRNA oligonucleotides and scrambled oligonucleotides (SC) by lipofection. After 30 µM ZVAD treatment for 30 min followed by 30 µM cisplatin for 36 h, lysates of cells were prepared and subjected to SDS-PAGE and analyzed by Western blotting with antibodies against ARNT, procaspase-3, caspase-3, p53, and actin. Similar results were obtained in three independent experiments.