title: Synergetic downregulation of 67 kDa laminin receptor by the green tea (Camellia sinensis) secondary plant compound epigallocatechin gallate: a new gateway in metastasis prevention?
abstract: BACKGROUND
  In traditional Chinese medicine, green tea is considered to have a life-prolonging effect, possibly as a result of its rich content of antioxidant tea polyphenols, and hence has the potential to prevent cancer. This study investigated the role of the major tea secondary plant compound epigallocatechin gallate (EGCG) for its inhibitory effects on the metastasis-associated 67 kDa laminin receptor (67LR).
  
  
  METHODS
  To clarify the impact of EGCG on siRNA-silenced expression of 67LR, we applied an adenoviral-based intestinal in vitro knockdown model, porcine IPEC-J2 cells. Quantitative real-time polymerase chain reaction was performed to analyze 67LR gene expression following treatment with physiological and pharmacological concentrations of EGCG (1.0 g/l, 0.1 g/l, 0.02 g/l and 0.002 g/l).
  
  
  RESULTS
  We report co-regulation of EGCG and 67LR, which is known to be an EGCG receptor. siRNA selectively and highly significantly suppressed expression of 67LR under the impact of EGCG in a synergetic manner.
  
  
  CONCLUSIONS
  Our findings suggest that 67LR expression is regulated by EGCG via a negative feedback loop. The explicit occurrence of this effect in synergy with a small RNA pathway and a plant-derived drug reveals a new mode of action. Our findings may help to provide insights into the many unsolved health-promoting activities of other natural pharmaceuticals.
authors.affiliation: Physiology Weihenstephan, Technische Universität München, Research Center for Nutrition and Food Science, Weihenstephaner Berg 3, 85350 Freising, Germany. jakob.mueller@wzw.tum.de
authors.forename: Jakob
authors.initials: J
authors.lastname: Müller
authors.forename: Michael W
authors.initials: MW
authors.lastname: Pfaffl
mesh_terms: D000818:Animals; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000031:analogs & derivatives / Q000378:metabolism; D002460:Cell Line; D015536:Down-Regulation / Q000187:drug effects*; D006801:Humans; D009362:Neoplasm Metastasis / Q000517:prevention & control; D009369:Neoplasms / Q000188:drug therapy* / Q000473:pathology; D010936:Plant Extracts / Q000494:pharmacology*; D017474:Receptors, Laminin / Q000235:genetics* / Q000378:metabolism
chemical_list: D010936:Plant Extracts; D017474:Receptors, Laminin; D002392:Catechin; C045651:epigallocatechin gallate