Stress via p53 pathway causes apoptosis by mitochondrial Noxa upregulation in doxorubicin-treated neuroblastoma cells

Oncogene. 2008 Jan 31;27(6):741-54. doi: 10.1038/sj.onc.1210672. Epub 2007 Aug 20.

Abstract

In this study, we employed a panel of cell lines to determine whether p53-dependent cell death in neuroblastoma (NB) cells is caused by apoptotic cellular function, and we further studied the molecular mechanism of apoptosis induced via the p53-dependent pathway. We obtained evidence that a type of p53-dependent stress, doxorubicin (Doxo) administration, causes accumulation of p53 in the nucleus of NB cells and phosphorylation of several serine residues in both Doxo-sensitive and -resistant cell lines. Upregulation of p53-downstream molecules in cells and upregulation of Noxa in the mitochondrial fraction were observed only in Doxo-sensitive NB cells. Significance of Noxa in the Doxo-induced NB cell death was confirmed by Noxa-knockdown experiments. Mitochondrial dysfunction, including cytochrome-c release and membrane potential disregulation, occurred and resulted in the activation of the intrinsic caspase pathway. However, in the Doxo-resistant cells, the accumulation in the nucleus and phosphorylation of p53 did not induce p53-downstream p21(Cip1/Waf1) expression and the Noxa upregulation, resulting in the retention of the mitochondrial homeostasis. Taken together, these findings indicate that the p53 pathway seems to play a crucial role in NB cell death by Noxa regulation in mitochondria, and inhibition of the induction of p53-downstream effectors may regulate drug resistance of NB cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibiotics, Antineoplastic / pharmacology*
  • Apoptosis* / genetics
  • Cell Line, Tumor
  • Doxorubicin / pharmacology*
  • Humans
  • Mitochondria / metabolism
  • Neuroblastoma / metabolism*
  • Proto-Oncogene Proteins c-bcl-2 / antagonists & inhibitors
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • Proto-Oncogene Proteins c-bcl-2 / metabolism*
  • RNA, Small Interfering / pharmacology
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism*
  • Up-Regulation

Substances

  • Antibiotics, Antineoplastic
  • PMAIP1 protein, human
  • Proto-Oncogene Proteins c-bcl-2
  • RNA, Small Interfering
  • Transcription Factors
  • Tumor Suppressor Protein p53
  • Doxorubicin