antineoplastic resistance

Antineoplastic resistance is the multidrug resistance of neoplastic (cancerous) cells, rather than drug resistance involving microorganisms such as bacteria, fungi and viruses. Cancer cells have the ability to become resistant to multiple drugs by many mechanisms:

• Increased efflux of drug (as by P-glycoprotein (ABCB1), multidrug resistance-associated protein (ABCC1), and breast cancer resistance protein (also known as mitoxantrone resistance associated protein, MXR, or ABCG2)
• Enzymatic deactivation (i.e., glutathione conjugation)
• Decreased permeability (drugs cannot enter the cell)
• Altered binding-sites
• Alternate metabolic pathways (the cancer compensates for the effect of the drug).