CDK4 (Cyclin-dependent kinase 4) is a serine/threonine kinase critical for cell cycle progression, particularly in the G1-to-S phase transition. It partners with cyclin D to phosphorylate and inactivate the retinoblastoma (RB) protein, releasing E2F transcription factors to drive DNA replication. Dysregulation of CDK4. due to gene amplification, mutations, or overexpression, is implicated in various cancers, including melanoma, breast cancer, and liposarcoma, making it a therapeutic target.
CDK4 antibodies are essential tools for studying its expression, localization, and activity in both research and clinical settings. In research, they enable detection via techniques like Western blotting, immunohistochemistry (IHC), and flow cytometry, aiding in understanding CDK4's role in tumorigenesis and treatment response. Clinically, CDK4 antibodies are used in companion diagnostics to identify patients likely to benefit from CDK4/6 inhibitors (e.g., palbociclib, ribociclib), which are FDA-approved for hormone receptor-positive breast cancer. These inhibitors block CDK4-cyclin D interactions, arresting cell cycle progression.
Challenges include ensuring antibody specificity, as CDK4 shares structural homology with CDK6. and optimizing assays to reflect functional protein levels. Recent studies also explore CDK4's involvement in drug resistance mechanisms, driving demand for reliable antibodies to support biomarker discovery and therapeutic monitoring. Advances in antibody engineering aim to improve sensitivity and reduce cross-reactivity, enhancing their utility in precision oncology.