Molecular modulators of CDK4/6 inhibitor response in experimental glioma identified through genome-wide CRISPR-Cas9 screening

The NOA-20 trial did not reveal a progression-free survival benefit of CDK4/6 inhibition plus radiation therapy in newly diagnosed, MGMT-unmethylated glioblastoma. In fact, a monotherapy with CDK4/6 inhibitors has not demonstrated efficacy in solid tumors.

We aimed at discovering response modulators to CDK4/6 inhibition, paving the way for rational combination therapies. We conducted genome-wide CRISPR-Cas9 screens in human glioma cell lines and stem-like cells (LN229, LN18, LNZ308, T98G, and GS-9) under CDK4/6 inhibition, employing knockout (Brunello library) and activation strategies (Calabrese library), followed by genetic and pharmacological validation of selected candidate genes in vitro and ex vivo (primary cultures) as well as the investigation of one functionally-instructed combination therapy in vivo.