TodeterminetheregulatoryeffectsofestrogenandcytokineIL-6andIL-8onthegrowthofepithelialovariancancer(OVCA),wefirstexaminedthestatusofestrogenreceptors(ERαandERβ),IL-6receptor(IL-6Rαandgp130),andIL-8receptor(IL-8RAandIL-8RB)onfiveepithelialOVCAcelllinesbysemiquantitativeRT-PCRandWesternblotanalysis.Resultsshowedthattheexpressionsofthesereceptorswerevariableonthefivecells.ThoseOVCAcellsexpressingthereceptorswereselectedtostudyrelatedmolecularmechanism.MTTassaywasperformedtoobservetheeffectsof17β-estradiol(E2),IL-6andIL-8oncellproliferation.WediscoveredthatE2markedlypromotedtheproliferationofCAOV-3andOVCAR-3cellinatime-anddose-dependentmanner.Tamoxifen(Txf),anERinhibitor,completelyblockedtheproliferationoftheE2-inducedcells,andIL-6-or/andIL-8-neutralizingantibodyonlyshowedpartiallyblockingactivity.IL-6andIL-8wereabletosignificantlystimulateCAOV-3andOVCAR-3cellproliferationinatime-anddose-dependentmanner,whichhadapotentialsynergisticeffectonCAOV-3cellsbutnotonOVCAR-3cells.Thecellproliferationinducedbythesetwocytokineswasabolishedcompletelybytheirspecificneutralizingantibodies,partiallybyTxf,butnotbyunrelatedgoatIgG.Takentogether,ourresultssuggestedthatestrogen,IL-6andIL-8couldmodulateOVCAgrowthbyformingareciprocalcascadewithamplifyingeffect.Cellular&MolecularImmunology.