Tris (2-chloroethyl) phosphate induces senescence-like phenotype of hepatocytes via the p21Waf1/Cip1-Rb pathway in a p53-independent manner

Environ Toxicol Pharmacol. 2017 Dec:56:68-75. doi: 10.1016/j.etap.2017.08.028. Epub 2017 Aug 31.

Abstract

Tris (2-chloroethyl) phosphate (TCEP) has been widely used as a plasticizer and flame retardant. TCEP as a potential carcinogen is often detected in the occupational and nature environments. To investigate effects of TCEP on human hepatocytes, we assessed cell growth rate, cellular membrane integrity, senescence-associated β-galactosidase (SA-β-Gal) activity and analyzed expression of regulators involved in the p53-p21Waf1/Cip1-Rb pathway in TCEP-treated L02 cells. The results showed TCEP increased the percentage of SA-β-Gal positive cells, decreased IL-6 levels, down-regulated the regulators of p38MAPK-NF-κB pathways, but up-regulated the regulators of p21Waf1/Cip1-Rb pathway in L02 cells. Furthermore, we measured the SA-β-Gal activity and expression of regulators involved in the p53-p21Waf1/Cip1-Rb pathway in L02-p53 cells and p53-null Hep3B cells. Similar results were found in L02-p53 cells and Hep3B cells. The findings demonstrated that TCEP induced senescence-like growth arrest via the p21Waf1/Cip1-Rb pathway in a p53-independent manner, without activation of the IL-6/IL6R, p38MAPK-NF-κB pathways in hepatocytes.

Keywords: IL-6; Rb; Senescence-like; Tris (2-chloroethyl) phosphate; p21; p53.

MeSH terms

  • Cell Count
  • Cell Division / drug effects
  • Cell Line
  • Cell Membrane / drug effects
  • Cell Proliferation / drug effects
  • Cellular Senescence
  • Cyclin-Dependent Kinase Inhibitor p21 / metabolism*
  • Flame Retardants / toxicity*
  • Gene Expression Regulation / drug effects
  • Hepatocytes / cytology
  • Hepatocytes / drug effects*
  • Hepatocytes / metabolism
  • Humans
  • Organophosphates / toxicity*
  • Phenotype
  • Retinoblastoma Protein / metabolism*
  • Signal Transduction / drug effects
  • Tumor Suppressor Protein p53 / metabolism*

Substances

  • CDKN1A protein, human
  • Cyclin-Dependent Kinase Inhibitor p21
  • Flame Retardants
  • Organophosphates
  • Retinoblastoma Protein
  • TP53 protein, human
  • Tumor Suppressor Protein p53
  • tris(chloroethyl)phosphate