Polyphosphate Derived from Lactobacillus brevis Inhibits Colon Cancer Progression Through Induction of Cell Apoptosis

Anticancer Res. 2016 Feb;36(2):591-8.

Abstract

Although probiotics are known to have antitumor activity, few bacteria-derived antitumor molecules have been identified. The present study explored an antitumor molecule derived from Lactobacillus brevis SBL8803 (L. brevis 8803) and the mechanisms that underlie its effects. Cell viability and apoptosis were assessed by a sulforhodamine B assay and terminal deoxynucleotidyl transferase dUTP staining, respectively. Phosphorylated extracellular signal-regulated kinase (ERK) and cleaved poly ADP-ribose polymerase (PARP) expression were detected by western blotting. The conditioned medium of L. brevis 8803 inhibited SW620 cells viability and the effect was reduced by the degradation of polyphosphate (poly P) in the conditioned medium. A xenograft model showed that poly P inhibited the growth of SW620 cells. Poly P induced the apoptosis of SW620 cells through activation of the ERK pathway. In contrast, in primary cultured cells derived from normal mouse, poly P did not affect cell viability. Probiotic-derived poly P is expected to be an antitumor drug with fewer adverse effects than conventional drugs.

Keywords: Colon cancer; ERK; antitumor effect; apoptosis; polyphosphate; probiotics.

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Blotting, Western
  • Cell Proliferation / drug effects
  • Colonic Neoplasms / drug therapy*
  • Colonic Neoplasms / pathology*
  • Culture Media, Conditioned / pharmacology*
  • Disease Progression
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Female
  • Humans
  • Lactobacillus brevis / chemistry*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Phosphorylation / drug effects
  • Polyphosphates / pharmacology*
  • Signal Transduction / drug effects
  • Tumor Cells, Cultured
  • Xenograft Model Antitumor Assays

Substances

  • Culture Media, Conditioned
  • Polyphosphates
  • Extracellular Signal-Regulated MAP Kinases