Akt isoform-specific effects on thyroid cancer development and progression in a murine thyroid cancer model

Sci Rep. 2020 Oct 27;10(1):18316. doi: 10.1038/s41598-020-75529-0.

Abstract

The Akt family is comprised of three unique homologous proteins with isoform-specific effects, but isoform-specific in vivo data are limited in follicular thyroid cancer (FTC), a PI3 kinase-driven tumor. Prior studies demonstrated that PI3K/Akt signaling is important in thyroid hormone receptor βPV/PV knock-in (PV) mice that develop metastatic thyroid cancer that most closely resembles FTC. To determine the roles of Akt isoforms in this model we crossed Akt1-/-, Akt2-/-, and Akt3-/- mice with PV mice. Over 12 months, thyroid size was reduced for the Akt null crosses (p < 0.001). Thyroid cancer development and local invasion were delayed in only the PVPV-Akt1 knock out (KO) mice in association with increased apoptosis with no change in proliferation. Primary-cultured PVPV-Akt1KO thyrocytes uniquely displayed a reduced cell motility. In contrast, loss of any Akt isoform reduced lung metastasis while vascular invasion was reduced with Akt1 or 3 loss. Microarray of thyroid RNA displayed incomplete overlap between the Akt KO models. The most upregulated gene was the dendritic cell (DC) marker CD209a only in PVPV-Akt1KO thyroids. Immunohistochemistry demonstrated an increase in CD209a-expressing cells in the PVPV-Akt1KO thyroids. In summary, Akt isoforms exhibit common and differential functions that regulate local and metastatic progression in this model of thyroid cancer.

Publication types

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

MeSH terms

  • Animals
  • Disease Models, Animal
  • Disease Progression
  • Fluorescent Antibody Technique
  • Gene Expression Regulation, Neoplastic
  • Mice
  • Mice, Knockout
  • Oligonucleotide Array Sequence Analysis
  • Protein Isoforms
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Receptors, Thyroid Hormone / metabolism
  • Thyroid Gland / metabolism
  • Thyroid Neoplasms / etiology*
  • Thyroid Neoplasms / metabolism
  • Thyroid Neoplasms / pathology

Substances

  • Protein Isoforms
  • Receptors, Thyroid Hormone
  • Akt1 protein, mouse
  • Akt2 protein, mouse
  • Proto-Oncogene Proteins c-akt