(A) Fluorescent images of HeLa cells incubated with plasmid encoding CRISPR-Cas9-mCherry and siRNA for MT-CO1. The red fluorescence from mCherry in mitochondria suggests the gene delivery and expression in mitochondria.
(B) Western blot analysis of MT-CO1 for HeLa cells treated by solvent control (PBS), free CRISPR-MT-CO1 plasmid, Mito-FLAG, and the mixture of Mito-FLAG and CRISPR-MT-CO1 plasmid. The reduced level of MT-CO1 protein in the combination treatment suggest the KO of the MT-CO1 gene.
(C) PCR analysis of the MT-CO1 gene for HeLa cells treated by solvent control (PBS), free CRISPR-MT-CO1 plasmid, Mito-FLAG, and the mixture of Mito-FLAG and CRISPR-MT-CO1 plasmid. The band of MT-CO1 gene in the combination group is hardly observed.
(D) ATP (red) visualization in HeLa cells incubated with solvent control (PBS), free CRISPR-MT-CO1 plasmid, Mito-FLAG, and the mixture of Mito-FLAG and CRISPR-MT-CO1 plasmid. The cells in the combination group exhibit little fluorescence from ATP-Red in mitochondria, indicating the disfunction of OXPHOS (MT-CO1 is the catalytic site of cytochrome c oxidase).
(E–G) The KO of MT-CO1 (E) leads to reduced efficiency in MDR, (F) sensitizes the cancer cell to cisplatin, and (G) reduces mitochondrial membrane potential. Data are presented as mean ± standard deviation.