CXCL1/GROα increases cell migration and invasion of prostate cancer by decreasing fibulin-1 expression through NF-κB/HDAC1 epigenetic regulation

Carcinogenesis. 2012 Dec;33(12):2477-87. doi: 10.1093/carcin/bgs299. Epub 2012 Oct 1.

Abstract

Inflammatory tumor microenvironments play pivotal roles in the development of cancer. Inflammatory cytokines such as CXCL1/GROα exert cancer-promoting activities by increasing tumor angiogenesis. However, whether CXCL1/GROα also plays a role in the progression of prostate cancer, particularly in highly invasive castration-resistant prostate cancer (CRPC), has not been investigated. We explored whether CXCL1/GROα enhances cell migration and invasion in PC-3 and DU145 CRPC. Induction of PC-3 and DU145 cancer progression by CXCL1/GROα is associated with increased AKT activation and IκB kinase α (IKKα) phosphorylation, resulting in nuclear factor-kappaB (NF-κB) activation. Activated NF-κB interacts with histone deacetylase 1 (HDAC1) to form a gene-silencing complex, which represses the expression of fibulin-1D by decreasing the acetylation of histone H3 and H4 on the NF-κB-binding site of the fibulin-1D promoter. Blockade of AKT2 by small hairpin RNA (shRNA) decreases IKKα phosphorylation, NF-κB nuclear translocation and cell migration, indicating that AKT is required in CXCL1/GROα-mediated NF-κB activation and cell migration. In addition, NF-κB and HDAC1 shRNA decrease the effect of CXCL1/GROα on fibulin-1D downregulation, migration and invasion, suggesting that the NF-κB/HDAC1 complex is also involved in CXCL1/GROα-mediated cancer progression. Our findings provide the first evidence that CXCL1/GROα decreases fibulin-1D expression in prostate cancer cells and also reveals novel insights into the mechanism by which CXCL1/GROα regulates NF-κB activation through the AKT pathway. Our results also clearly establish that co-operation of NF-κB and HDAC1 regulates fibulin-1D expression by epigenetic modification. Our study suggests that inhibition of CXCL1/GROα-mediated AKT/NF-κB signaling may be an attractive therapeutic target for CRPC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium-Binding Proteins / genetics
  • Calcium-Binding Proteins / physiology*
  • Cell Line, Tumor
  • Cell Movement
  • Chemokine CXCL1 / physiology*
  • Epigenesis, Genetic
  • Epithelial-Mesenchymal Transition
  • Histone Deacetylase 1 / physiology*
  • Humans
  • Male
  • NF-kappa B / physiology*
  • Neoplasm Invasiveness
  • Prostatic Neoplasms / pathology*
  • Proto-Oncogene Proteins c-akt / physiology
  • Signal Transduction

Substances

  • CXCL1 protein, human
  • Calcium-Binding Proteins
  • Chemokine CXCL1
  • NF-kappa B
  • fibulin
  • Proto-Oncogene Proteins c-akt
  • HDAC1 protein, human
  • Histone Deacetylase 1