Dietary Prevention of Hormone Refractory Prostate Cancer in Lobund-Wistar Rats: A Review of Studies in a Relevant Animal Model

摘要

Lobund-Wistar(LW)rats,whichhavehightestosteronelevels,arepredisposedtodevelophormone-refractoryprostatecancer(HRPC)spontaneouslyandbymethylnitrosourea(MNU)induction,andthedevelopmentofHRPCprogressesthrough2stages.ThispaperreviewsseveralstudiesinwhichLWratswereplacedonsoy-containingdietsandwereevaluatedfordevelopmentofeitherspontaneousorMNU-inducedprostatecancer.Thepremalignant,testosterone-dependentstageisinhibitedbytestosteronedeprivation.Intheabsenceoftestosteronedeprivation,tumorigenesisprogressesspontaneouslytothetestosterone-independentrefractorystage.InLWrats:moderatecaloricrestrictionpreventeddevelopmentofspontaneousprostatecancer;dietary4-hydroxyphenylretinamidepreventedMNU-inducedprostatecancer;anddietarysupplementationwithsoyproteinisolatewithhighisoflavonespreventedspontaneousandinducedtumorsandledtomoderatereductionofserumtestosterone.Inrats12moofageandyounger,changingfromthecontroldiettothesoy+isoflavonedietsignificantlypreventedprogressionofspontaneoustumorstotherefractorystageofdisease.TumorsthatdevelopedspontaneouslyandafterMNUinductionshowedsimilardevelopmentalstagesandmorphology,butMNU-inducedtumorshadshorterlatencyperiodsbeforedevelopment.Theaccumulateddataindicatethatsoy-baseddietsareeffectiveinthepreventionofprostatecancer.