Fig. 7

Mechanism for ABC transporters regulated by the level of PI3K 110α or 110β subunit. The level of P110 subunits may regulate P-gp and BCRP directly, altering drug-sensitivity of the cells and yielding changed cell proliferation and survival ability. Knockout of P110 subunits induced down-regulation of P-gp and BCRP, and suggested the potentiality of P110α and P110β to be applied as targets for reversal of MDR of cancers. This route can be separate from AKT activation that had been regarded as a downstream effect in PI3K/AKT signaling pathway, playing an important role in the activation of many factors through phosphorylation. Italic characters indicate the major function of CRISPR/Cas9 deletion of P110α or P110β from the MDR cancer cells