Table 3.

Viability of A549 and HepG2 cells treated with proteasome and transport receptor importin-β inhibitors, and intoxicated with PE-native and PE-NLS. A549 cells were pre-incubated with MG132 (proteasome inhibitor) or importazole (transport receptor importin-β inhibitor), while HepG2 cells were pre-incubated with lactacystin (proteasome inhibitor) or importazole. Both cell types were then intoxicated with PE-native or PE-NLS. Viability was assessed after 48 h. Ctrl represents cells treated only with inhibitors. The values represent means ± SEM of four experiments. * Statistically significant difference at p < 0.05; ** statistically significant difference at p < 0.01.

Toxin	Viability (%)
	A549	A549 + MG132	A549 + Importazole	HepG2	HepG2 + Lactacystin	HepG2 + Importazole
PE-native	49.1 ± 2.8	24.7 ± 2.7 *	53.3 ± 6.2	49.7 ± 2.0	27.9 ± 2.3 *	54.3 ± 1.0
PE-NLS	52.2 ± 2.7	32.6 ± 4.9 *	56.2 ± 3.8	52.9 ± 3.6	42.5 ± 3.1 *	68.7 ± 1.0 **
Ctrl	-	82.6 ± 0.5	122.5 ± 3.3	-	100.3 ± 0.8	100.1 ± 4.3