The role of vascular endothelial growth factor, interleukin 8, and insulinlike growth factor in sustaining autophagic DIRAS3-induced dormant ovarian cancer xenografts

Cancer. 2019 Apr 15;125(8):1267-1280. doi: 10.1002/cncr.31935. Epub 2019 Jan 8.

Abstract

Background: Re-expression of the imprinted tumor suppressor gene DIRAS family GTPase 3 (DIRAS3) (aplysia ras homology member I [ARHI]) induces autophagy and tumor dormancy in ovarian cancer xenografts, but drives autophagic cancer cell death in cell culture. The current study explored the tumor and host factors required to prevent autophagic cancer cell death in xenografts and the use of antibodies against those factors or their receptors to eliminate dormant autophagic ovarian cancer cells.

Methods: Survival factors (insulinlike growth factor 1 [IGF-1], vascular endothelial growth factor [VEGF], and interleukin 8 [IL-8]) were detected with growth factor arrays and measured using enzyme-linked immunoadsorbent assay analysis. Phosphorylation of protein kinase B (AKT), phosphorylation of extracellular signal-regulated kinase (ERK), nuclear localization of translocation factor EB (TFEB) or forkhead box O3a (FOXo3a), and expression of microtubule-associated proteins 1A/1B light chain 3B (MAPLC3B; LC3B) were examined using Western blot analysis. The effect of treatment with antibodies against survival factors or their receptors was studied using DIRAS3-induced dormant xenograft models.

Results: Ovarian cancer cells grown subcutaneously in nude mice exhibited higher levels of phosphorylated ERK/AKT activity and lower levels of nuclear TFEB/FOXo3a, MAPLC3B, and autophagy compared with cells grown in culture. Induction of autophagy and dormancy with DIRAS3 was associated with decreased ERK/AKT signaling. The addition of VEGF, IGF-1, and IL-8 weakened the inhibitory effect of DIRAS3 on ERK/AKT activity and reduced DIRAS3-mediated TFEB or FOXo3a nuclear localization and MAPLC3B expression in ovarian cancer cells. Treatment with antibodies against VEGF, IL-8, and IGF receptor inhibited the growth of dormant xenografts, thereby prolonging survival from 99 to >220 days (P < .05) and curing a percentage of mice.

Conclusions: Treatment with a combination of anti-VEGF, anti-IL-8, and anti-IGF receptor antibodies prevented the outgrowth of dormant cells and prolonged survival in a preclinical model.

Keywords: autophagy; insulinlike growth factor receptor (IGF-R); interleukin 8 (IL-8); ovarian cancer; tumor dormancy; vascular endothelial growth factor (VEGF).

Publication types

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

MeSH terms

  • Animals
  • Antibodies / administration & dosage*
  • Antibodies / pharmacology
  • Autophagy / drug effects
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Interleukin-8 / antagonists & inhibitors
  • Interleukin-8 / metabolism*
  • MAP Kinase Signaling System / drug effects
  • Mice
  • Mice, Nude
  • Ovarian Neoplasms / drug therapy*
  • Ovarian Neoplasms / metabolism
  • Phosphorylation
  • Somatomedins / antagonists & inhibitors
  • Somatomedins / metabolism*
  • Vascular Endothelial Growth Factor A / antagonists & inhibitors
  • Vascular Endothelial Growth Factor A / metabolism*
  • Xenograft Model Antitumor Assays
  • rho GTP-Binding Proteins / genetics
  • rho GTP-Binding Proteins / metabolism*

Substances

  • Antibodies
  • CXCL8 protein, human
  • DIRAS3 protein, human
  • Interleukin-8
  • Somatomedins
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A
  • rho GTP-Binding Proteins