Fig. 2

The effect of the deletion of cdk4 or cdk6 gene on the regulation of ABCB1 and the reversal of ABCB1-mediated MDR. A An all-in-one plasmid for CRISPR/Cas9 gene editing. B Western blot and RT-PCR analysis verifying the specific knockout of the targeted gene. The red stars depict the decrease in the copies of the target PCR. Truncated proteins are depicted by head-down arrows. C ABCB1 expression in the cdk4- or cdk6-deficient KB-C2 cells. The cell lysates containing identical amounts of total proteins were used for determining gene knockout in (B) and ABCB1 expression (C). D, E The alteration of ABCB1-mediated MDR in the cdk6- or cdk4-deficient KB-C2 cells. Two substrate anticancer drugs of ABCB1, colchicine and paclitaxel, were used to compare ABCB1-mediated MDR in the cancer cells