Palbociclib inhibits proliferation of human adrenocortical tumor cells

Adrenocortical cancer (ACC) is a rare malignant tumor. Pharmacological therapy is based on mitotane administered alone or in association with the EDP regimen (etoposide, doxorubicin, and cisplatin). However, the prognosis of ACC patients not amenable to surgery still remains poor and newer treatment strategies are needed. Drugs targeting cell cycle could be a relevant new therapeutic approach for patients with advanced ACC. Cell cycle is controlled by several key proteins, including CDKs (cyclin-dependent kinases), which are the target of recently discovered cell-cycle checkpoint inhibitors. Palbociclib is a CDK4/6-inhibitor that is active against a broad range of tumors and has an acceptable toxicity, being neutropenia being the most relevant side effect. This drug is actually approved in the management of locally advanced or metastatic breast cancer. In this study, we investigated in vitro the effect of Palbociclib in NCI-H295R ACC cells and human ACC primary cultures.