An Experimental Study Of Intervention On Human Differentiated Thyroid Carcinoma With Tamoxifen And Tretinoin In Vitro

Objective To observe the effects of tamoxifen (TAM) and all-trans-retinoic acid(RTRA) on human differentiated papillary thyroid carcinoma cell line KAT5and follicularcarcinoma cell line FTC-133in proliferation, apoptosis and invasion in vitro, and reveal thecombined effect.Methods Cell lines KAT5and FTC-133cultured with TAM (15and30μmol/L) andATRA (0.5and1μmol/L) respectively or combined. MTT assay was selected to detect thesurvival ratio (SR) of the cell lines at the indicated time (12h,24h,48h, or72h). The rate ofearly apoptosis was determined by flow cytometer (FCM) at the time which the cell lineshad been induced by the drug(s) for48h. After24h pretreatment of the drug(s), theinvasion ability of the cell lines was assessed using Transwell assay.Results The proliferation of the cell lines KAT5and FTC-133can be inhibitedeffectively by TAM and RTRA in a dose and time-dependent manner, and the survival ratesof the maximum concentration of the combined group in72h are18.61%and28.35%respectively (P<0.05); With the rise of the drugs concentration, the early apoptosis andinhibition of invasive ability are more and more obvious, their early apoptosis rate andpenetrating cells are15.46±0.51/24.89±0.42,71.33±4.31/47.00±3.79,14.57±0.41/20.54±0.37,102.33±5.68/78.67±4.26respectively, the differences are statisticallysignificant (P<0.05).When TAM combined with RTRA, the inhibitory effect on cell growthand invasion was enhanced, and apoptosis induced efficiency was further strengthenedcompared with single-agent in cell line KAT5(Q>1). The joint effect of the drugs was thesingle drug efficacy added only in cell line FTC-133.Conclusion Small doses of TAM combined with RTRA have a good synergy indifferentiated thyroid cancer cell on the suppression of proliferation and invasion，andapoptosis induction. It shows a good clinical application in the treatment of thyroidcarcinoma.