In cancer, the function of caspases can be altered through various mechanisms:
1. Downregulation or Mutation: Cancer cells may downregulate caspase expression or acquire mutations in caspase genes that render them inactive. For instance, mutations in caspase-8 are observed in some cancers, leading to impaired apoptotic signaling.
2. Inhibitors of Apoptosis Proteins (IAPs): These proteins can inhibit caspase activity. Overexpression of IAPs is common in cancers and contributes to the resistance of cancer cells to apoptosis-inducing therapies.
3. Dysregulated Signaling Pathways: Alterations in pathways upstream of caspase activation, such as the Bcl-2 family of proteins and the p53 tumor suppressor, can prevent the initiation of the caspase cascade.
