Melatonin Enhances the Efficacy of Cdk4/6 Inhibitor in Breast Cancer Cells Via Down-Regulating the Expression of Cyclind1

Breast Cancer (BC) is the most common malignancy and cause of death among women. CDK4/6 inhibitor-Palbociclib (PD) isethionate is a new chemotherapeutic agent in the treatment of breast cancer that works through blocking retinoblastoma phosphorylation protein and regulating the retinoblastoma (RB)-E2F pathway to inhibit cell cycle in the G0/G1 phase. However, the toxicity and resistance of PD are the primary limiting factors of this therapeutic effect. Melatonin (MLT) exerts anti-tumor activity in BC and arrests the cell cycle in the G0/G1 phase.