The sirtuins inhibitor cambinol reverses sorafenib resistance in human hepatocellular carcinoma HepG2 cells

DELPRATO, CB; LIVORE, VI; CARMELI BARBERIS, E; FERRETTI, AC; LUCCI, A; COMANZO, CG; QUIROGA, AD; ALVAREZ ML; MOTTINO, AD; CARRILLO, MC; CEBALLOS, MP

Congreso; SAFIS; 2019

Sorafenib (SFB) is the only approved drug for hepatocellular carcinoma (HCC) treatment but it only prolongs patients? median survival by nearly 3 months. The main reason underlying the impaired sensitivity to SFB is multidrug resistance (MDR). MDR often results from upregulation of ABC transporters, like P-glycoprotein (P-gp) and multidrug resistance-associated protein 3 (MRP3). Sirtuins 1 and 2 (SIRTs1/2) are overexpressed in HCC and are associated with tumoral progression and MDR. Previous results from our group showed that the SIRTs1/2 inhibitor cambinol (CAMB) diminished P-gp and MRP3 expression in HepG2 cells and exacerbated the effects of SFB on cellular viability and migration in 2D and 3D cultures of these cells. Aim: to analyze whether SIRTs1/2 activities blockage overcomes MDR during SFB treatment. Methods: 2D and 3D cultures of the HepG2 cell line were treated for 72 h with SFB (2 μM) in presence or absence of CAMB (50 μM). Proliferation (2D: PCNA-western blot; 3D: Ki67-immunofluorescence), apoptosis (2D and 3D: CellEventCaspase 3/7 reagent), invasion (2D: transwellassay) and ABC expression (2D: P-gp and MRP3-western blot) were assayed. Results: In 2D and 3D cultures, cells treated with SFB and CAMB showed a greater fall in cellular proliferation (2D: SBF -17%, SFB+CAMB -98%*#) and presented with more apoptosis than cells treated with SFB alone. In 2D cultures, treatment with SFB and CAMB diminished invasion compared to SFB treatment (SBF -70%*, SFB+CAMB -85%*#). Whereas SFB induced ABC expression in 2D cultures (P-gp: +154*, MRP3: +92*) treatment with CAMB+SFB reduced ABC protein levels (P-gp: -50*#, MRP3: -44*#) compared to control cells. *p