Identification of a TLR2-regulated gene signature associated with tumor cell growth in gastric cancer

Oncogene. 2017 Sep 7;36(36):5134-5144. doi: 10.1038/onc.2017.121. Epub 2017 May 8.

Abstract

Toll-like receptors (TLRs) are key regulators of innate immune responses, and their dysregulation is observed in numerous inflammation-associated malignancies, including gastric cancer (GC). However, the identity of specific TLRs and their molecular targets which promote the pathogenesis of human GC is ill-defined. Here, we sought to determine the clinical utility of TLR2 in human GC. TLR2 mRNA and protein expression levels were elevated in >50% of GC patient tumors across multiple ethnicities. TLR2 was also widely expressed among human GC cell lines, and DNA microarray-based expression profiling demonstrated that the TLR2-induced growth responsiveness of human GC cells corresponded with the up-regulation of six anti-apoptotic (BCL2A1, BCL2, BIRC3, CFLAR, IER3, TNFAIP3) and down-regulation of two tumor suppressor (PDCD4, TP53INP1) genes. The TLR2-mediated regulation of these anti-apoptotic and tumor suppressor genes was also supported by their increased and reduced expression, respectively, in two independent genetic GC mouse models (gp130F/F and Gan) characterized by high tumor TLR2 expression. Notably, enrichment of this TLR2-regulated gene signature also positively correlated with augmented TLR2 expression in human GC tumors, and served as an indicator of poor patient survival. Furthermore, treatment of gp130F/F and cell line-derived xenograft (MKN1) GC mouse models with a humanized anti-TLR2 antibody suppressed gastric tumor growth, which was coincident with alterations to the TLR2-driven gene signature. Collectively, our study demonstrates that in the majority of GC patients, elevated TLR2 expression is associated with a growth-potentiating gene signature which predicts poor patient outcomes, thus supporting TLR2 as a promising therapeutic target in GC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / metabolism*
  • Cell Proliferation*
  • Female
  • Gene Expression Profiling*
  • Humans
  • Mice
  • Mice, Inbred NOD
  • Neoplasm Invasiveness
  • Neoplasm Staging
  • Prognosis
  • Stomach Neoplasms / genetics
  • Stomach Neoplasms / metabolism
  • Stomach Neoplasms / pathology*
  • Survival Rate
  • Toll-Like Receptor 2 / genetics
  • Toll-Like Receptor 2 / metabolism*
  • Tumor Cells, Cultured
  • Xenograft Model Antitumor Assays

Substances

  • Biomarkers, Tumor
  • TLR2 protein, human
  • Toll-Like Receptor 2