Effects of environmental pollutants on signaling pathways in rat pituitary GH3 adenoma cells

Environ Res. 2017 Oct:158:660-668. doi: 10.1016/j.envres.2017.07.015. Epub 2017 Jul 18.

Abstract

An increased rate of acromegaly was reported in industrialized areas, suggesting an involvement of environmental pollutants in the pathogenesis and behavior of GH-secreting pituitary adenomas. Based on these premises, the aim of the study was to evaluate the effects of some widely diffused pollutants (i.e. benzene, BZ; bis(2-ethylhexyl) phthalate, DEHP and polychlorinated biphenyls, PCB) on growth hormone secretion, the somatostatin and estrogenic pathways, viability and proliferation of rat GH-producing pituitary adenoma (GH3) cells. All the pollutants induced a statistically significant increase in GH secretion and interfered with cell signaling. They all modulated the expression of SSTR2 and ZAC1, involved in the somatostatin signaling, and the expression of the transcription factor FOXA1, involved in the estrogen receptor signaling. Moreover, all the pollutants increased the expression of the CYP1A1, suggesting AHR pathway activation. None of the pollutants impacted on cell proliferation or viability. Present data demonstrate that exposure to different pollutants, used at in vivo relevant concentrations, plays an important role in the behavior of GH3 pituitary adenoma cells, by increasing GH secretion and modulating several cellular signaling pathways. These observations support a possible influence of different pollutants in vivo on the GH-adenoma aggressiveness and biological behavior.

Keywords: Benzene; DEHP; GH; PCB; Pituitary adenoma; Pollution; Somatostatin receptor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzene / toxicity
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Diethylhexyl Phthalate / toxicity
  • Environmental Pollutants / toxicity*
  • Estrogens / genetics
  • Estrogens / metabolism
  • Gene Expression / drug effects*
  • Growth Hormone / metabolism*
  • Growth Hormone-Secreting Pituitary Adenoma / chemically induced
  • Polychlorinated Biphenyls / toxicity
  • Rats
  • Signal Transduction / drug effects*
  • Somatostatin / genetics
  • Somatostatin / metabolism

Substances

  • Environmental Pollutants
  • Estrogens
  • Somatostatin
  • Growth Hormone
  • Diethylhexyl Phthalate
  • Polychlorinated Biphenyls
  • Benzene