ABSTRACT
OBJECTIVE:To study the inhibitory effects of phosphatidylinositol 3-kinase (PI3K) inhibitor LY29400 (“LY”) combined with indole-3-carbinol (I3C) on the proliferation of human anaplastic thyroid carcinoma FRO cells. METHODS:RFO cells in logarithmic growth phase were divided into blank control group,I3C (250 μmol/L) group,LY (10 μmol/L) group and combination (I3C of 250 μmol/L + LY of 10 μmol/L) group,which were subject to 24,48 and 72 h drug action. MTT method was used to determine and calculate the inhibitory rates of the cells in all groups,flow cytometry assay to determine the apoptosis rates after 48 h action,Western blot method to determine the expressions of Capspase-3 proteins thereafter and immunohistochemi-cal method to determine the expressions of Bcl-2 and Bax thereafter. RESULTS:The inhibitory rate obviously increased with the ex-tension of drug action time,with statistical significance at each time point in combination group (P<0.05). Compared to I3C group and LY group,combination group had higher inhibitory rate,apoptosis rate and the expressions of Capspase-3 protein and Bax,and lower Bcl-2 expression and ratio of Bcl-2 to Bax,with statistical significance (P<0.01). CONCLUSIONS:LY com-bined with I3C has synergistic inhibitory effects on the proliferation of FRO cells by a mechanism which may be related to apopto-sis induced by down-regulating Bcl-2 expression,up-regulating Bax expression and activating Caspase cascade reaction.