Inflammatory cytokine production in tumor cells upon chemotherapy drug exposure or upon selection for drug resistance

PLoS One. 2017 Sep 15;12(9):e0183662. doi: 10.1371/journal.pone.0183662. eCollection 2017.

Abstract

Tumor Necrosis Factor alpha (TNF-α) has been shown to be released by tumor cells in response to docetaxel, and lipopolysaccharides (LPS), the latter through activation of toll-like receptor 4 (TLR4). However, it is unclear whether the former involves TLR4 receptor activation through direct binding of the drug to TLR4 at the cell surface. The current study was intended to better understand drug-induced TNF-α production in tumor cells, whether from short-term drug exposure or in cells selected for drug resistance. ELISAs were employed to measure cytokine release from breast and ovarian tumor cells in response to several structurally distinct chemotherapy agents and/or TLR4 agonists or antagonists. Drug uptake and drug sensitivity studies were also performed. We observed that several drugs induced TNF-αrelease from multiple tumor cell lines. Docetaxel-induced cytokine production was distinct from that of LPS in both MyD88-positive (MCF-7) and MyD88-deficient (A2780) cells. The acquisition of docetaxel resistance was accompanied by increased constitutive production of TNF-αand CXCL1, which waned at higher levels of resistance. In docetaxel-resistant MCF-7 and A2780 cell lines, the production of TNF-α could not be significantly augmented by docetaxel without the inhibition of P-gp, a transporter protein that promotes drug efflux from tumor cells. Pretreatment of tumor cells with LPS sensitized MyD88-positive cells (but not MyD88-deficient) to docetaxel cytotoxicity in both drug-naive and drug-resistant cells. Our findings suggest that taxane-induced inflammatory cytokine production from tumor cells depends on the duration of exposure, requires cellular drug-accumulation, and is distinct from the LPS response seen in breast tumor cells. Also, stimulation of the LPS-induced pathway may be an attractive target for treatment of drug-resistant disease.

MeSH terms

  • Antineoplastic Agents* / adverse effects
  • Antineoplastic Agents* / pharmacology
  • Docetaxel
  • Drug Resistance, Neoplasm* / drug effects
  • Drug Resistance, Neoplasm* / immunology
  • Gene Expression Regulation* / drug effects
  • Gene Expression Regulation* / immunology
  • Humans
  • Lipopolysaccharides / toxicity
  • MCF-7 Cells
  • Myeloid Differentiation Factor 88 / immunology
  • Neoplasm Proteins / immunology*
  • Neoplasms* / drug therapy
  • Neoplasms* / immunology
  • Neoplasms* / pathology
  • Taxoids* / adverse effects
  • Taxoids* / pharmacology
  • Toll-Like Receptor 4 / immunology
  • Tumor Necrosis Factor-alpha / immunology*

Substances

  • Antineoplastic Agents
  • Lipopolysaccharides
  • MYD88 protein, human
  • Myeloid Differentiation Factor 88
  • Neoplasm Proteins
  • TLR4 protein, human
  • Taxoids
  • Toll-Like Receptor 4
  • Tumor Necrosis Factor-alpha
  • Docetaxel

Grants and funding

The study was supported by a grant from the Northern Cancer Foundation of Sudbury, along with additional support for the purchase of reagents through a grant to Tom Kovala from the Northern Ontario School of Medicine, https://www.ncfsudbury.com/; http://www.nosm.ca/research/default.aspx.