Recent advances reveal IL-8 signaling as a potential key to targeting breast cancer stem cells

Breast Cancer Res. 2013;15(4):210. doi: 10.1186/bcr3436.

Abstract

Breast cancer stem-like cells (CSCs) are an important therapeutic target as they are purported to be responsible for tumor initiation, maintenance, metastases, and disease recurrence. Interleukin-8 (IL-8) is upregulated in breast cancer compared with normal breast tissue and is associated with poor prognosis. IL-8 is reported to promote breast cancer progression by increasing cell invasion, angiogenesis, and metastases and is upregulated in HER2-positive cancers. Recently, we and others have established that IL-8 via its cognate receptors, CXCR1 and CXCR2, is also involved in regulating breast CSC activity. Our work demonstrates that in metastatic breast CSCs, CXCR1/2 signals via transactivation of HER2. Given the importance of HER2 in breast cancer and in regulating CSC activity, a pathway driving the activation of these receptors would have important biological and clinical consequences, especially in tumors that express high levels of IL-8 and other CXCR1/2-activating ligands. Here, we review the IL-8 signaling pathway and the role of HER2 in maintaining an IL-8 inflammatory loop and discuss the potential of combining CXCR1/2 inhibitors with other treatments such as HER2-targeted therapy as a novel approach to eliminate CSCs and improve patient survival.

Publication types

  • Review

MeSH terms

  • Animals
  • Breast Neoplasms / drug therapy
  • Breast Neoplasms / metabolism*
  • Breast Neoplasms / pathology
  • Female
  • Humans
  • Inflammation / metabolism
  • Inflammation / pathology
  • Interleukin-8 / metabolism*
  • Molecular Targeted Therapy
  • Neoplastic Stem Cells / drug effects
  • Neoplastic Stem Cells / metabolism*
  • Receptor, ErbB-2 / metabolism
  • Receptors, Interleukin-8A / metabolism
  • Receptors, Interleukin-8B / metabolism
  • Signal Transduction* / drug effects

Substances

  • Interleukin-8
  • Receptors, Interleukin-8A
  • Receptors, Interleukin-8B
  • Receptor, ErbB-2