Antiproliferative and apoptotic effects of combined treatment of interferon alpha-2b (IFN) and vitamin e (vit E) on SK HEP-1 cells

LUCCI, A; COMANZO, CG; VERA, MC; LORENZETTI, F; FERRETTI, AC; CEBALLOS, MP; QUIROGA, AD; ALVAREZ, ML; CARRILLO, MC

Congreso; SAFIS; 2019

Our group demonstrated that IFN is an effective antitumor agent in the prevention and treatment of hepatocellular carcinoma (HCC) given its apoptotic and antiproliferative effects. Besides, it was shown that vit E exerts inhibitory effects on liver cancer due to its apoptotic, antiangiogenic and antiproliferative activities. Previously, we observed that combined treatment of IFN with vit E significantly decreased cell viability, migration and invasion of human HCC cell line SK HEP-1, in comparison with single treatments. The aim of the present work is to deepen the study of the effects of combining IFN and vit E, with particular focus on proliferation and apoptosis. Methods: SK-HEP 1 cells were treated with 10000 U/I IFN and 25 uM δ-Tocotrienol (an isomer of vit E). Treatments were performed for 72 h using single drugs (IFN-group and E-group) and their combination (IFN-E-group). Also, a control group treated with drugs vehicles was included. We performed: a) annexin V-FITC assay to determine total apoptosis by flow citometry, b) western blot studies to analyze the expression of PCNA (marker of proliferation), proapoptotic Bax and antiapoptotic Bcl-Xl proteins, and c) dichlorofluorescein assay to evaluate reactive oxygen species (ROS) production. Results: IFN-E-group showed a higher increase in total apoptosis (+520%*&), compared with monotherapies (IFN-group: +75%*; E-group: +90%*). Also, IFN-E-group showed a significant decrease in PCNA expression (-35%*&) together with an increase in Bax protein expression (+65 %*&) and a decrease in Bcl-Xl expression (-85%*&), compared with monotherapies (IFN-group: PCNA: -17%*, Bax: +23%*, Bcl-Xl: -55%*; E-group: PCNA: -20%*, Bax: +25%*, Bcl-Xl: -60%*). On the other hand, IFN-E-group showed a significant increase in ROS production (+480%*&) compared with monodrug therapies (IFN-group: +50%*, E-group: +150%*) (*p