TABLE 5

Loss of mitochondrial function suppresses lapatinib and obatoclax-induced changes in protein expression/protein phosphorylation in MCF7 cells

MCF7 cells and MCF7 Rho zero cells were treated with vehicle (DMSO), lapatinib (2 μM), obatoclax (50 nM), or lapatinib + obatoclax for 12 to 24 h. Western blotting was performed to detect changes in phosphorylation/expression of proteins. The protein levels were quantified by densitometry analysis and are relative vehicle protein level (defined as 1.00) (±S.E.M., n = 3).

	LC3II	P-H2AX	p62	LAMP 2	ATG4A	ATG7
BT474
12 h
Vehicle	1.00	1.00	1.00	1.00	1.00	1.00
6 h
50 nM GX	1.69	1.55	0.96	0.89	1.23	0.89
2 μM Lap	1.02	1.39	0.95	0.93	1.56	1.12
50 nM GX + 2 μM Lap	2.32	2.80^*	1.68^*	1.39^*	1.91^*	1.13
12 h
50 nM GX	1.63	1.14	1.23	0.59	1.02	1.13
2 μM Lap	1.00	1.14	1.25	1.02	2.29	1.04
50 nM GX + 2 μM Lap	5.75	6.37^*	1.41^*	0.32^‡	2.42^*	0.89
Rho zero
12 h
Vehicle	1.00	1.00	1.00	1.00	1.00	1.00
6 h
50 nM GX	1.37	1.64	0.96	0.90	0.99	0.96
2 μM Lap	1.00	1.33	0.95	0.95	0.98	1.12
50 nM GX + 2 μM Lap	1.52^*^†	2.14^*^†	1.03	0.93	0.98	1.11
12 h
50 nM GX	1.51	2.08	1.02	0.90	0.99	1.17
2 μM Lap	1.02	0.95	1.03	0.91	1.02	1.05
50 nM GX + 2 μM Lap	2.74^*^†	2.51^*^†	1.20^*^†	0.90	1.12	1.12

VEH, vehicle; Lap, lapatinib; GX, obatoclax (GX-15-070).
↵* p < 0.05 greater than the corresponding vehicle control.
↵† p < 0.05 less than the corresponding value in siSCR cells.
↵‡ p less than the corresponding vehicle control.