Fig 2: Immunohistochemical expression of CSNK2A1 and pSIRT6 in human osteosarcoma and statistical and survival analysis in osteosarcoma. (a) Negative and positive examples of immunohistochemical expression of CSNK2A1 and pSIRT6 in human osteosarcoma tissue. (b) The cut-off points of CSNK2A1 and pSIRT6 expression were determined using receiver operating characteristic curve analysis. The cut-off points of the immunohistochemical staining score for CSNK2A1 and pSIRT6 were twelve for both marker, and were determined at the point with the highest area under the curve (AUC). The red arrow (CSNK2A1) and blue arrow (pSIRT6) indicate the cut-off points. (c) Kaplan–Meier survival curves for overall survival and relapse-free survival according to the expression of CSNK2A1 and pSIRT6 in 37 osteosarcoma patients.

Fig 3: CSNK2A1 involvement in the apoptotic effects of doxorubicin in osteosarcoma cells with flow cytometry analysis. (a) U2OS and KHOS/NP osteosarcoma cells were transfected with control shRNA or shRNA for CSNK2A1 and treated with 0.2 µM doxorubicin for 24 h. (b) U2OS and KHOS/NP osteosarcoma cells were transfected with empty vector or wild-type CSNK2A1 and treated with 0.2 µM doxorubicin for 24 h. The apoptosis of cells was evaluated via flow-cytometry analysis with staining with propidium iodide and for annexin V. **; p < 0.001.

Fig 4: Synergistic interaction of 5-fluorouracil (5-FU) with CK2 inhibitors, i.e., 14B or CX-4945, in inhibition of viability of the MDA-MB-231 cell line. (A,C) Representative CalcuSyn software-simulated isobolograms. (B,D) Fraction affected-combination index (Fa-CI) curves for the respect combinations of 5-FU with either 14B or CX-4945 after 72 h of treatment, generated after fitting Fa obtained from the MTT assay.

Fig 5: Predicted protein kinases contributing to the temporal changes of phosphorylation states of selected proteins in neurons undergoing excitotoxic cell death.Temporal changes of the phosphorylation states of neuronal Map1b, Tau, Jip3, Git1, Stmn1, Ppfia3, Erk1/2, Ndrg2, cyclin Y, Eif5b, Ctnna2 and Ctnnd2 at 5, 15, 30, 60 and 240 min after glutamate overstimulation. These proteins have at least one phosphosite exhibiting time-dependent increase in phosphorylation level. The upstream protein kinases targeting these sites are predicted by comparing the phosphosite sequences with the known optimal phosphorylation sequences of protein kinases and literature-curated knowledge. These predicted upstream kinases including GSK3, cdk5, Rock1, JNK, MEK, SGK1 and CK2 are activated by specific post-receptor signalling events initiated by overstimulation of the neuronal iGluRs. The question mark indicates that the post-receptor signalling events directing activation of the predicted upstream kinases remain unclear. All data shown in the plots are the mean of normalised log2 medium/light ratios at different time points following glutamate treatment. The error bars denote standard deviations. The plot depicting the time-dependent changes of the phosphorylation of Mapt (Tau) at Ser-696 in excitotoxicity is also shown in Fig. 5a