CXCR2-driven ovarian cancer progression involves upregulation of proinflammatory chemokines by potentiating NF-κB activation via EGFR-transactivated Akt signaling

PLoS One. 2013 Dec 20;8(12):e83789. doi: 10.1371/journal.pone.0083789. eCollection 2013.

Abstract

Ovarian cancer is an inflammation-associated malignancy with a high mortality rate. CXCR2 expressing ovarian cancers are aggressive with poorer outcomes. We therefore investigated molecular mechanisms involved in CXCR2-driven cancer progression by comparing CXCR2 positive and negative ovarian cancer cell lines. Stably CXCR2 transfected SKOV-3 cells had a faster growth rate as compared to control cells transfected with empty vector. Particularly, tumor necrosis factor (TNF), abundantly expressed in ovarian cancer, enhanced cell proliferation by decreasing the G0-G1 phase in CXCR2 transfected cells. TNF increased nuclear factor-κB (NF-κB) activity to a greater degree in CXCR2 transfected cells than control cells as well as provided a greater activation of IκB. CXCR2 transfected cells expressed higher levels of its proinflammatory ligands, CXCL1/2 and enhanced more proliferation, migration, invasion and colony formation. CXCR2 positive cells also activated more EGFR, which led to higher Akt activation. Enhanced NF-κB activity in CXCR2 positive cells was reduced by a PI3K/Akt inhibitor rather than an Erk inhibitor. CXCL1 added to CXCR2 positive cells led to an increased activation of IκB. CXCL1 also led to a significantly greater number of invasive cells in CXCR2 transfected cells, which was blocked by the NF-κB inhibitor, Bay 11-7082. In addition, enhanced cell proliferation in CXCR2 positive cells was more sensitive to CXCL1 antibody or an NF-κB inhibitor. Finally, CXCR2 transfection of parental cells increased CXCL1 promoter activity via an NF-κB site. Thus augmentation of proinflammatory chemokines CXCL1/2, by potentiating NF-κB activation through EGFR-transactivated Akt, contributes to CXCR2-driven ovarian cancer progression.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Cell Line, Tumor
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Chemokine CXCL1 / genetics
  • Chemokine CXCL1 / metabolism
  • Chemokines / genetics
  • Chemokines / metabolism*
  • Disease Progression
  • ErbB Receptors / genetics*
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Gene Knockdown Techniques
  • Humans
  • Ligands
  • NF-kappa B / metabolism*
  • Neoplasm Invasiveness
  • Ovarian Neoplasms / pathology*
  • Promoter Regions, Genetic / genetics
  • Proto-Oncogene Proteins c-akt / metabolism*
  • RNA, Small Interfering / genetics
  • Receptors, Interleukin-8B / deficiency
  • Receptors, Interleukin-8B / genetics
  • Receptors, Interleukin-8B / metabolism*
  • Signal Transduction
  • Transcriptional Activation
  • Tumor Necrosis Factor-alpha / pharmacology
  • Up-Regulation* / drug effects

Substances

  • Chemokine CXCL1
  • Chemokines
  • Ligands
  • NF-kappa B
  • RNA, Small Interfering
  • Receptors, Interleukin-8B
  • Tumor Necrosis Factor-alpha
  • EGFR protein, human
  • ErbB Receptors
  • Proto-Oncogene Proteins c-akt