Learning Objective
By the end of this section, learners should be able to explain the role of P-glycoprotein in multidrug resistance, its mechanism of action, and its clinical significance in cancer therapy.
Definition
- P-glycoprotein, also known as multidrug resistance protein 1 (MDR1), is an ATP-dependent efflux pump.
- It is expressed in certain cancer cells and functions to export toxins and drugs out of the cell.
Clinical Significance
- Mechanism of chemotherapy resistance: Pumps out chemotherapeutic agents → reduced intracellular drug concentration → decreased responsiveness over time.
- Associated with resistance to multiple drugs, including anthracyclines, vinca alkaloids, and taxanes.
- Targeting or inhibiting P-glycoprotein is an area of research to overcome multidrug resistance in cancer therapy.
Activity
High-Yield Step 1 Point
- P-glycoprotein is a classic mechanism of acquired chemotherapy resistance and a common exam topic for pharmacology and oncology.
