Figure 1
From: Circumvention of multi-drug resistance of cancer cells by Chinese herbal medicines
Mechanisms of MDR towards cancer chemotherapeutic drugs. Cancer cells can develop resistance to multiple drugs by various mechanisms as depicted. Mechanisms include (a) decreased uptake of drug, (b) reduced intracellular drug concentration by efflux pumps, (c) altered cell cycle checkpoints, (d) altered drug targets, (e) increased metabolism of drug and (f) induced emergency response genes to impair apoptotic pathway.