Phospho-ΔNp63α/SREBF1 protein interactions: bridging cell metabolism and cisplatin chemoresistance

Cell Cycle. 2012 Oct 15;11(20):3810-27. doi: 10.4161/cc.22022. Epub 2012 Sep 5.

Abstract

Tumor protein (TP)-p53 family members (TP63, TP63 and TP73) are guardians of the genome and key players in orchestrating the cellular response to cisplatin treatment. Cisplatin-induced phosphorylation of ΔNp63α was shown to have a role in regulating intracellular ΔNp63α protein levels. We previously found that squamous cell carcinoma (SCC) cells exposed to cisplatin displayed the ATM-dependent phosphorylation of ΔNp63α (p-ΔNp63α), which is critical for the transcriptional regulation of specific downstream mRNAs and microRNAs and is likely to underlie the chemoresistance of SCC cells. However, SCC cells expressing non-p-ΔNp63α became more cisplatin-resistant. We also found that p-ΔNp63α forms complexes with a number of proteins involved in cell death response through regulation of cell cycle arrest, apoptosis, autophagy, RNA splicing and chromatin modifications. Here, we showed that p-ΔNp63α induced ARG1, GAPDH, and CPT2 gene transcription in cisplatin-sensitive SCC cells, while non-p-ΔNp63α increased a transcription of CAD, G6PD and FASN genes in cisplatin-resistant SCC cells. We report that the p-ΔNp63α-dependent regulatory mechanisms implicated in the modulation of plethora of pathways, including amino acid, carbohydrate, lipid and nucleotide metabolisms, thereby affect tumor cell response to cisplatin-induced cell death, suggesting that the ATM-dependent ΔNp63α pathway plays a role in the resistance of tumor cells to platinum therapy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / pharmacology
  • Ataxia Telangiectasia Mutated Proteins
  • Carcinoma, Squamous Cell / drug therapy
  • Carcinoma, Squamous Cell / genetics*
  • Carcinoma, Squamous Cell / metabolism
  • Cell Cycle Checkpoints / drug effects
  • Cell Cycle Proteins / antagonists & inhibitors
  • Cell Cycle Proteins / genetics*
  • Cell Cycle Proteins / metabolism
  • Cell Line, Tumor
  • Cisplatin / pharmacology
  • DNA-Binding Proteins / antagonists & inhibitors
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism
  • Drug Resistance, Neoplasm / genetics*
  • Gene Expression Regulation, Neoplastic
  • Genes, Reporter
  • Head and Neck Neoplasms / drug therapy
  • Head and Neck Neoplasms / genetics*
  • Head and Neck Neoplasms / metabolism
  • Humans
  • Luciferases
  • Neoplasm Proteins / antagonists & inhibitors
  • Neoplasm Proteins / genetics*
  • Neoplasm Proteins / metabolism
  • Phosphorylation / drug effects
  • Protein Binding
  • Protein Serine-Threonine Kinases / antagonists & inhibitors
  • Protein Serine-Threonine Kinases / genetics*
  • Protein Serine-Threonine Kinases / metabolism
  • Signal Transduction / drug effects
  • Sterol Regulatory Element Binding Protein 1 / genetics
  • Sterol Regulatory Element Binding Protein 1 / metabolism
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • Transfection
  • Tumor Suppressor Proteins / antagonists & inhibitors
  • Tumor Suppressor Proteins / genetics*
  • Tumor Suppressor Proteins / metabolism

Substances

  • Antineoplastic Agents
  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • Neoplasm Proteins
  • SREBF1 protein, human
  • Sterol Regulatory Element Binding Protein 1
  • TP63 protein, human
  • Transcription Factors
  • Tumor Suppressor Proteins
  • Luciferases
  • ATM protein, human
  • Ataxia Telangiectasia Mutated Proteins
  • Protein Serine-Threonine Kinases
  • Cisplatin