Chemotherapy Resistance Mechanisms
Start with the big picture
Resistance can arise through several distinct mechanisms. Tumor cells may reduce intracellular drug levels by increasing efflux transporters, inactivate drugs, or alter drug targets so treatment is less effective. Other mechanisms include bypass signaling, enhanced DNA repair, impaired apoptosis, and cell-cycle changes that help cells survive treatment. EMT, cancer stem-cell features, tumor microenvironment conditions, pharmacokinetic barriers, and epigenetic changes can also contribute. Because different mechanisms may operate together, the lesson connects these mechanisms with strategies such as combination therapy and biomarker-guided treatment. Examples include transporter-mediated efflux, target mutations, and DNA repair changes that affect responses to particular drug classes.
What you'll learn
- Distinguish intrinsic from acquired chemotherapy resistance.
- Explain how efflux transporters and drug inactivation can reduce treatment effectiveness.
- Identify target alterations, bypass signaling, and enhanced DNA repair as resistance mechanisms.
- Describe how apoptosis, cell-cycle changes, EMT, and the tumor microenvironment contribute to resistance.
- Connect combination therapy and biomarker testing with approaches to address resistance.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
