title: Flavonoids can block PSA production by breast and prostate cancer cell lines.
abstract: BACKGROUND
  Prostatic carcinoma is the most commonly diagnosed cancer and the second leading cause of cancer death of North American men. Combined androgen blockade (CAB) is one treatment option for prostate cancer, using estrogen agonists, luteinizing hormone-releasing hormone (LHRH) agonists and non-steroidal anti-androgens such as nilutamide and cyproterone acetate. Since many of these drugs have serious side effects, many patients are searching for "natural" alternatives or complements to traditional therapy. These include phytoestrogens found in soy and other plant foods. Such compounds have only started to be evaluated for potential androgen-blocking activity. Inhibition of production of androgen-regulated proteins, including prostate-specific antigen (PSA), is one indicator of androgen blocking.
  
  
  METHODS
  The ability of 72 flavonoids and related compounds to inhibit PSA production in a breast cancer cell line, BT-474, and a prostate cancer cell line (PC-3), transfected with the human androgen receptor cDNA, PC-3(AR)(2) was examined.
  
  
  RESULTS
  Twenty-two of the 72 flavonoids tested were found to significantly block PSA production by the BT-474 cell line at the highest tested concentration (10(-5) mol/l), with 17 of these compounds inhibiting production of PSA in the PC-3(AR)(2) cells as well.
  
  
  CONCLUSIONS
  That several flavonoids may significantly block production of this androgen-regulated protein. It will be worthwhile to examine these compounds as possible candidates for prostate cancer prevention or management.
authors.affiliation: Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Rachel S
authors.initials: RS
authors.lastname: Rosenberg Zand
authors.forename: David J A
authors.initials: DJ
authors.lastname: Jenkins
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Brown
authors.forename: Eleftherios P
authors.initials: EP
authors.lastname: Diamandis
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D005260:Female; D005419:Flavonoids / Q000494:pharmacology*; D019833:Genistein / Q000494:pharmacology; D006801:Humans; D008297:Male; D017430:Prostate-Specific Antigen / Q000187:drug effects / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D005419:Flavonoids; D019833:Genistein; D017430:Prostate-Specific Antigen; C004541:biochanin A