USE OF MULTICELLULAR TUMOR SPHEROIDS AS A MODEL OF HEPATOCELLULAR CARCINOMA TO STUDY THE EFFECTS OF SORAFENIB AND EX-527 ON PROLIFERATION, MIGRATION AND APOPTOSIS

PALMA, NF; QUIROGA, AD; CEBALLOS, MP

Congreso; Sociedad Argentina de Fisiología; 2023

Introduction: Chemoresistance (CR) counteracts the efficiency of sorafenib (SFB), a first-line therapy for hepatocellularcarcinoma (HCC). Despite nowadays there exist other treatment options, HCC is a chemorefractory cancer and therapeuticstrategies are still challenging. Sirtuins 1 and 2 (SIRT1/2) promote cancer progression and CR. Multicellular tumor spheroids(MCTS) are 3D models that provide more reliable results than standard 2D in vitro cell cultures, since they mimic features of invivo tumors. Also, it is now accepted that stromal cells in solid tumors contribute to cancer progression and CR. We have shownthat a combined treatment of SFB and EX-527 (EX), a SIRT1/2 inhibitor, reduces the viability of MCTS composed of SFB-resistantHCC and stroma cells. Objectives: to study the effects of SFB and EX on proliferation, migration and apoptosis using MCTS withthe same composition. Methods: a SFB-resistant HCC cell line was established after incubating Huh7 cells for 6 months withincreasing doses of SFB (Huh7-SR). MCTS of Huh7-SR, endothelial (EA.hy926) and hepatic stellate (LX-2) cells, in a ratio 1:0.3:0.3,respectively, were obtained by liquid overlay technique. Then, MCTS were treated for 72h with SFB 4μM(1), EX 40μM(2), SFB4μM+EX 40 μM(3) or DMSO (control group: C). Proliferation rate and migration capability (in an adherent surface) werecalculated as volume 72/0h and area 72/0h, respectively. Caspase-3/7 activity was determined at 72h using a green fluorescentreagent and apoptosis was estimated as fluorescence intensity/volume. Results: treatments reduced the proliferation (1: -16.3%*; 2: -54.7%*; 3: -62.6%*#) and the migration capacity (1: -13.5%*; 2: -13.4%*; 3: -46.2*#) of MCTS. Apoptosis wasinduced by treatments (1: +114.5*; 2: +127.8%*; 3: +181.6*). *p<0.05 vs. C. #p<0.05 vs. individual treatment. Conclusion:although all treatments were able to reduce proliferation and migration and to induce apoptosis, the combination of SFB and EXwas superior to either treatment alone. More importantly, these responses were achieved in an in vitro model that betterreflects tumor behavior in a context of SFB resistance and cancer-stroma interactions.