Fig. 1: GAL1 protects HepG2 HCC cells from DOX- and sorafenib-induced cell death in vitro.

A Western blot and densitometric analysis showing relative GAL1 expression in non-transfected (HepG2) and transfected with pcDNA3.1-LGALS1 (HepG2-GAL1), expression vector without insert (HepG2-M), GAL1 shRNA plasmid (HepG2-shGAL1) or scrambled shRNA plasmid (HepG2-shScr) cell lysates. β-tubulin was used as loading control (n = 5). **p < 0.01, ****p < 0.0001, with respect to the corresponding controls. ^&&&&p < 0.0001 with respect to HepG2 cells. B Cell viability (MTT assay) in GAL1-overexpressing, GAL1-silenced and control cells incubated with increasing concentrations of DOX (0-5 µM) for 48 or 72 h. Results are expressed as the mean of cell viability percentage with respect to the corresponding untreated cell line (100%) ± SEM (n = 8). The experimental data were fitted to dose–response curves by non-linear regression as described in “Materials and methods”. C Apoptosis in HepG2-M and HepG2-GAL1 cells after 5 µM DOX treatment for 24 or 48 h. Cells were stained with nuclear fluorescent dye Hoechst 33258 and nuclear morphology was analyzed by epifluorescence microscopy (40X). Cells that underwent apoptosis showed condensed and/or fragmented nuclei (upper panel). Percentages of apoptotic nuclei were calculated as described in Materials and Methods. Results are expressed as the mean ± SEM (n = 4) (lower panel). *p < 0.05 with respect to HepG2-M cells. D Cell viability (MTT assay) in GAL1-overexpressing and control HepG2 cells cultured with increasing concentrations of sorafenib (5–100 µM) for 24 h. Results are expressed as the mean of cell viability percentage relative to untreated cells (100%) ± SEM (n = 6). The experimental data were fitted to dose–response curves by non-linear regression.