Cell-bound exopolysaccharide from probiotic bacteria induces autophagic cell death of tumour cells

Y. Kim, S. Oh, H. S. Yun, S. Oh, S. H. Kim

Research output: Contribution to journalArticlepeer-review

129 Citations (Scopus)


Aim: Lactic acid bacteria (LAB) are beneficial micro-organisms that have been associated with several probiotic effects in both humans and animals. Here, using proteome analysis, we investigate the antitumour effects of cell-bound exopolysaccharides (cb-EPS) isolated from Lactobacillus acidophilus 606 on colon cancer cells and explore the proteins critical for their antitumour activity. Methods and Results: cb-EPS inhibited the proliferation of HT-29 colon cancer cells by directly affecting cell morphology and not the cell cycle. Using two-dimensional polyacrylamide gel electrophoresis coupled with matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF/MS) and immunoblot analysis, we found that cb-EPS dramatically induced Beclin-1 and GRP78, and affected Bcl-2 and Bak regulation. Conclusions: The results of this study indicate that cb-EPS are antitumourigenic against HT-29 colon cancer cells and that this activity is because of the activation of autophagic cell death promoted directly by the induction of Beclin-1 and GRP78, as well as indirectly through the induction of Bcl-2 and Bak. Significance and Impact of the Study: These results may contribute to understanding the novel mechanisms by which probiotic bacteria induce tumour cell death via autophagy.

Original languageEnglish
Pages (from-to)123-130
Number of pages8
JournalLetters in Applied Microbiology
Issue number2
Publication statusPublished - 2010 Aug


  • antitumour activity
  • autophagy
  • cb-EPS
  • two-dimensional polyacrylamide gel electrophoresis (2D-PAGE)

ASJC Scopus subject areas

  • Applied Microbiology and Biotechnology


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