The mechanism of action of ribociclib in the treatment of breast cancer

Ribociclib (Ribociclib) is a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor, mainly used to treat certain types of Breast cancer, especially hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) breast cancer. Its mechanism of action mainly involves the following aspects:

1. InhibitsCDK4/6Activity: Ribociclib by selectively inhibiting cyclin-dependent kinases4and pan>6 (CDK4 and CDK6) activity, thereby arresting cell cycle progression. In the cell cycle, CDK4 and CDK6 combine with their ligands cyclin D to form complexes that promote the G1 phase of the cell cycle. By inhibiting CDK4/6 activity, ribociclib (ribociclib) can prevent cancer cells from entering the S phase (DNA synthesis phase), thereby inhibiting the proliferation and growth of cancer cells.

2. Prevent cell proliferation: Normal regulation of the cell cycle is crucial to maintaining normal cell proliferation and differentiation. The inhibitory effect of Ribociclib (Riboxiclib) is mainly concentrated in the proliferation phase of tumor cells, thereby inhibiting the proliferation ability of cancer cells. This prevents tumor cells from continuing to divide and proliferate, ultimately inhibiting tumor growth.

3. With endocrine therapy: Ribociclib (ribociclib) is often used in combination with endocrine therapy, especially aromatase inhibitors (such as anastrozole or efenone). This combination treatment more comprehensively inhibits the growth and spread of hormone receptor-positive (HR+) breast cancer. Endocrine therapy inhibits the stimulation of tumor cells by estrogen, and Ribociclib By inhibitingCDK4/6activity and synergizing with each other, the therapeutic effect is enhanced.

4. Prolongation of the cell cycleG1 phase:The effect of ribociclib causes tumor cells to stay in the G1 phase of the cell cycle, thus prolonging the duration of the G1 phase. This prolonged G1 phase helps increase cells' sensitivity to treatment and also gives the immune system more time to identify and eliminate abnormal cells.

To sum up,Riboxiclib (Riboxiclib) prevents the proliferation and growth of cancer cells by inhibitingCDK4/6activity, thus exerting its effect in the treatment of breast cancer. Its combined use with endocrine therapy can improve the effectiveness of treatment, extend the progression-free survival of patients, and improve the prognosis of breast cancer patients to a certain extent.