Fig. 4.

CK2 signaling promotes neurosphere formation. In vitro limiting dilution assay (LDA) was used to assess the neurosphere formation of GBM stem cells on the indicated days. a X456 cells cultured with CX-4945 (0–10 μM) (day 12) or d transfected with siRNA targeting CK2α/α′ (day 10) were assessed for neurosphere formation. e qPCR of CK2α (left) and CK2α′ (right) 48 h post-transfection with non-targeting siRNA or CK2α and CK2α′ siRNA. b X12 cells (day 11) and c freshly isolated cells from xenoline X6 (day 19) were cultured with CX-4945 (0–10 μM) and assessed for neurosphere formation (n = 2). f Stem cell frequency of xenolines following CK2 inhibition with CX-4945 or knockdown of CK2 catalytic subunits. *p < 0.05 comparing to DMSO or NT siRNA