Rhamnogalacturonan I containing homogalacturonan inhibits colon cancer cell proliferation by decreasing ICAM1 expression

Carbohydr Polym. 2015 Nov 5:132:546-53. doi: 10.1016/j.carbpol.2015.06.082. Epub 2015 Jul 3.

Abstract

Pectin modified with pH, heat or enzymes, has previously been shown to exhibit anti-cancer activity. However, the structural requirements for modified pectin bioactivity have rarely been addressed. In this study several pectin extracts representing different structural components of pectin were assessed for effects against colon cancer cells. Rhamnogalacturonan I (RGI) extracts reduced proliferation of DLD1 and HCT116 colon cancer cells in a dose- and time-dependent manner. RGI reduced ICAM1 gene expression and siRNA-mediated knockdown of ICAM1 expression decreased cell proliferation providing a potential novel mechanism for the anti-cancer activity of pectin. Structural analysis of bioactive and non-bioactive RGIs suggested that a homogalacturonan component is maybe essential for the anti-proliferative activity, furthering the understanding of the structural requirements for pectin bioactivity.

Keywords: Colon cancer; Galactan; Homogalacturonan; ICAM1; Modified pectin; Rhamnogalacturonan I.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / toxicity
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Colonic Neoplasms / metabolism
  • Colonic Neoplasms / pathology
  • HCT116 Cells
  • Humans
  • Intercellular Adhesion Molecule-1 / chemistry
  • Intercellular Adhesion Molecule-1 / genetics
  • Intercellular Adhesion Molecule-1 / metabolism*
  • Magnetic Resonance Spectroscopy
  • Pectins / chemistry*
  • Pectins / toxicity
  • RNA Interference
  • RNA, Small Interfering / metabolism

Substances

  • Antineoplastic Agents
  • RNA, Small Interfering
  • rhamnogalacturonan I
  • Intercellular Adhesion Molecule-1
  • Pectins
  • polygalacturonic acid