The PML isoform IV is a negative regulator of nuclear EGFR's transcriptional activity in lung cancer

Carcinogenesis. 2013 Aug;34(8):1708-16. doi: 10.1093/carcin/bgt109. Epub 2013 Apr 4.

Abstract

Epidermal growth factor receptor (EGFR) is a membrane-bound receptor tyrosine kinase, which can transduce intracellular signals responsible for cell proliferation. It is frequently overexpressed and/or constitutively activated in non-small cell lung cancer and thus is considered as a major cause of this disease. Recently, EGFR has been found in the nucleus where the nuclear EGFR (nEGFR) can function as a transcription factor activating the transcription of genes such as cyclin D1 gene (CCND1), which is essential for cell proliferation. Nevertheless, how nEGFR's transcriptional activity is regulated remains unclear. Promyelocytic leukemia protein (PML) is a tumor suppressor, which is lost in various cancers including lung cancer. However, the role of PML in the suppression of lung cancer growth is still unclear. When we investigated the role of PML in the regulation of lung cancer cell growth, we found that PML isoform IV (PMLIV) preferentially represses the growth of lung cancer cells bearing constitutively active EGFR. Besides, when growing in the EGFR activating conditions, the growth of EGFR wild-type bearing A549 cells has been repressed by PMLIV overexpression. We also found that PMLIV can interact physically with nEGFR and represses the transcription of nEGFR target genes. We showed that PMLIV is recruited by nEGFR to the target promoters and reduces the promoter histone acetylation level via HDAC1. Together, our results suggest that PMLIV interacts with nEGFR upon EGFR activation and represses the transcription of nEGFR target genes such as CCND1 and thus leading to inhibition of the lung cancer cell growth.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation
  • Animals
  • Cell Growth Processes / physiology
  • Cell Line
  • Cell Line, Tumor
  • Cyclin D1 / genetics
  • Cyclin D1 / metabolism
  • ErbB Receptors / genetics*
  • ErbB Receptors / metabolism
  • Female
  • HEK293 Cells
  • Histone Deacetylase 1 / genetics
  • Histone Deacetylase 1 / metabolism
  • Histones / genetics
  • Histones / metabolism
  • Humans
  • Lung Neoplasms / genetics*
  • Lung Neoplasms / metabolism
  • Lung Neoplasms / pathology
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / metabolism
  • Promoter Regions, Genetic
  • Promyelocytic Leukemia Protein
  • Protein Isoforms
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • Transcription, Genetic
  • Tumor Suppressor Proteins / genetics*
  • Tumor Suppressor Proteins / metabolism

Substances

  • CCND1 protein, human
  • Histones
  • Nuclear Proteins
  • Promyelocytic Leukemia Protein
  • Protein Isoforms
  • Transcription Factors
  • Tumor Suppressor Proteins
  • Cyclin D1
  • PML protein, human
  • EGFR protein, human
  • ErbB Receptors
  • HDAC1 protein, human
  • Histone Deacetylase 1