Targeting cyclin D-CDK4/6 sensitizes immune-refractory cancer by blocking the SCP3–NANOG axis

Immunoediting caused by antitumor immunity drives tumor cells to acquire refractory phenotypes. We demonstrated previously that tumor antigen–specific T cells edit these cells such that they become resistant to CTL killing and enrich NANOG^high cancer stem cell-like cells. In this study, we show that synaptonemal complex protein 3 (SCP3), a member of the Cor1 family, is overexpressed in immunoedited cells and upregulates NANOG by hyperactivating the cyclin D1–CDK4/6 axis. The SCP3–cyclin D1–CDK4/6 axis was preserved across various types of human cancer and correlated negatively with progression-free survival of cervical cancer patients. Targeting CDK4/6 with the inhibitor palbociclib reversed multiaggressive phenotypes of SCP3^high immunoedited tumor cells and led to long-term control of the disease. Collectively, our findings establish a firm molecular link of multiaggressiveness among SCP3, NANOG, cyclin D1, and CDK4/6 and identify CDK4/6 inhibitors as actionable drugs for controlling SCP3^high immune-refractory cancer. Significance: These findings reveal cyclin D1-CDK4/6 inhibition as an effective strategy for controlling SCP3^high immune-refractroy cancer.