CPT1A, AMPKα-1, and LKB1 siRNAs effectively knock down expression at the protein level. The efficiency of the transient siRNA approach was assessed at the protein level by Western blotting coupled with densitometry for A) CPT1A, B) AMPKα-1, and C) LKB1 in transiently transfected 184B5, MCF-7, and MDA-MB-231 cells. Lysates from cells in which B) AMPKα-1 was knocked down were also probed for changes in the levels of phosphorylated ACC (pACC) and CPT1A. Those derived from cells in which C) LKB1 was targeted were further probed for changes in phosphorylated AMPKα (pAMPKα). Vehicle = V, CPT1A siRNA = C, AMPKα siRNA = A, and LKB1 siRNA = L. Results represent the mean ± SEM of three independent experiments.