What are the Mechanisms of Cyclin and CDK Dysregulation in Cancer?
Several mechanisms can lead to the dysregulation of cyclins and CDKs in cancer:
Genetic mutations: Mutations in genes encoding cyclins or CDKs can result in their constitutive activation or overexpression. For instance, mutations in the CCND1 gene can lead to increased levels of Cyclin D1. Epigenetic changes: Promoter methylation or histone modifications can alter the expression levels of cyclins and CDKs. Loss of regulatory proteins: Proteins such as p21 and p27 are CDK inhibitors. Their loss or downregulation can lead to unchecked CDK activity. Oncogenic signaling pathways: Activation of pathways like PI3K/AKT can upregulate cyclin expression.
