Expression of Peroxisome Proliferator-Activated Receptor alpha (PPARα) in somatotropinomas: Relationship with Aryl hydrocarbon receptor Interacting Protein (AIP) and in vitro effects of fenofibrate in GH3 cells

Mol Cell Endocrinol. 2016 May 5:426:61-72. doi: 10.1016/j.mce.2016.02.005. Epub 2016 Feb 10.

Abstract

Purpose: To search for a possible role of Peroxisome Proliferator-Activated Receptor α (PPARα), a molecular partner of the Aryl hydrocarbon receptor Interacting Protein (AIP), in somatotropinomas.

Methods: Tumours from 51 acromegalic patients were characterized for PPARα and AIP expression by immunohistochemistry (IHC) and/or Real Time RT-PCR. Data were analysed according to tumour characteristics and pre-operative treatment with somatostatin analogues (SSA). The effects of fenofibrate were studied in GH3 cells in vitro.

Results: PPARα was expressed in most somatotropinomas. A modest relationship was found between PPARα and AIP expression, both being significantly higher in the presence of pre-operative SSA. However, only AIP expression was influenced by the response to treatment. Dual effects of fenofibrate were observed in GH3 cells, consisting of cell growth inhibition and an increase in GH secretion inhibited by octreotide.

Conclusions: PPARα is a new player in somatotropinomas. Potential interactions between PPARα agonists and SSA may deserve further investigation.

Keywords: Acromegaly; Aryl hydrocarbon receptor interacting protein (AIP); Fenofibrate; GH(3) cells; Peroxisome proliferator-activated receptor (PPARα); Somatostatin analogues.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma / metabolism*
  • Adolescent
  • Adult
  • Aged
  • Animals
  • Apoptosis
  • Cell Line
  • Cell Proliferation
  • Child
  • Female
  • Fenofibrate / pharmacology*
  • Growth Hormone-Secreting Pituitary Adenoma / metabolism*
  • Humans
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Male
  • Middle Aged
  • PPAR alpha / metabolism*
  • Pituitary Gland / metabolism
  • Pituitary Gland / pathology
  • Rats
  • Young Adult

Substances

  • Intracellular Signaling Peptides and Proteins
  • PPAR alpha
  • aryl hydrocarbon receptor-interacting protein
  • Fenofibrate