Several factors contribute to drug resistance in cancer. These include:
Genetic mutations: Cancer cells can undergo mutations that alter drug targets or activate alternative survival pathways. Efflux pumps: Overexpression of proteins such as P-glycoprotein can pump drugs out of cells, reducing their efficacy. Epigenetic changes: Modifications in DNA methylation and histone acetylation can alter gene expression without changing the DNA sequence, leading to resistance. Microenvironment: The tumor microenvironment, including cancer-associated fibroblasts and immune cells, can protect cancer cells from drugs. Drug inactivation: Some cancer cells can metabolize and inactivate drugs before they exert their effects.
