Inducible Knockout of 14-3-3 Attenuates Proliferation and Spheroid Formation in a Human Glioblastoma Cell Line U87MG

Glioblastomas (GBs) are the most common and malignant brain tumors in adults. A protein encoded by the gene YWHAB, 14-3-3 beta, is commonly found to be upregulated throughout the initiation and progression of GB. The 14-3-3 beta has oncogenic roles in several different types of cancer cells through interactions with proteins such as Bad, FBI1, Raf-1, Cdc25b, and others. Previous RNA interference studies have shown that 14-3-3 beta promotes proliferation, cell cycle progression, and migration and invasion of GB cells. However, despite the many oncogenic functions of 14-3-3 beta, a CRISPR/Cas9 knockout model of 14-3-3 beta has not been investigated. This study confirmed previous findings and showed that siRNA inhibition of 14-3-3 beta results in reduced cellular proliferation in a human glioblastoma cell line, U87MG. We also used a YWHAB Tet-On CRISPR/Cas9 U87MG cell line that, upon doxycycline induction, leads to robust Cas9 expression and subsequent knockout of 14-3-3 beta. Using this model, we show that loss of 14-3-3 beta significantly reduces cellular proliferation and spheroid formation of U87MG cells.