Background: Although emerging animal- or cell-based evidence supports the relationship between casein kinase 2 alpha protein 1 (CSNK2A1) and cancers, no pan-cancer analysis is available. Thus, this report aimed to display the prognostic landscape of CSNK2A1 in pan-cancer and investigate the relationship between CSNK2A1 and tumor immunity. Methods: In the current study, we investigated the expression pattern, genetic alterations and survival analysis of CSNK2A1 in pan-cancer across multiple datasets and online platforms. The correlations between CSNK2A1 expression and tumor immunity were explored and visualized via Rlanguage software. Following this, immunohistochemical (IHC) staining and Kaplan–Meier survival analysis were conducted in clinical patients for proving the bioinformatic findings. Analysis of protein–protein interaction and gene functional enrichment was conducted using GeneMANIA platform and gene set enrichment analysis (GSEA), respectively. Results: In TCGA, tumor tissue had ahigher expression level of CSNK2A1 compared with that in corresponding normal tissue. An increased expression level of CSNK2A1 was related to poor clinical prognosis in most types of cancer such as LIHC. The following expression and survival analysis in clinical liver hepatocellular carcinoma (LIHC) patients confirmed these TCGA findings. CSNK2A1 expression had significant positive correlations with pro-tumor-infiltrating immune cells (TIICs) like M1-macrophages and fibroblasts, and significant negative correlations with anti-tumor-TIICs like activated CD8+ Tcells and NK cells, suggesting specific interactions between CSNK2A1 and certain TIICs subtypes. Furthermore, CSNK2A1 expression had the most significant positive correlations with common markers of immune checkpoint including programmed death ligand-1 (PDL1) in LIHC. These findings were validated by an IHC analysis. GSEA analysis demonstrated that high expression of CSNK2A1 was related to cell signaling pathways and immunity-related activities. Conclusion: These findings suggested that CSNK2A1 was not only related to poor clinical prognosis in cancer like LIHC but also anovel immunotherapy-related biomarker in cancers, especially in LIHC, shedding new light on anti-tumor strategy.

Background: The childhood patients with mixed-lineage leukemia rearrangement (MLL-r) gene have worse outcome than non-MLL, and thus often treated with high-risk chemotherapy regimens, so targeted therapy is important for this type of leukemia. This purpose of study was to explore the effects of ruxolitinib on the proliferation, apoptosis, and cell cycle of Nalm-6 cells. Methods: In this study, human acute lymphoblastic leukemia (ALL) cell line Nalm-6 was used as the research object. By constructing an MLL overexpression vector to transfect Nalm-6 cells, exogenous JAK2/STAT3 signal pathway inhibitor ruxolitinib was applied to observe the proliferation, apoptosis, and cell cycle changes of the transfected Nalm-6 cells. Western blot was performed to determine the proteins (MLL-BP, JAK, STAT) involved in the mechanism of action of MLL-r leukemia. CCK8 assay and flow cytometry (FCM) were used for testing the proliferation and apoptosis among MLL-BP transfected Nalm-6 cells. Results: Firstly, we determine the IC50 of ruxolitinib on Nalm-6 cells. Secondly, FCM and CCK8 showed that ruxolitinib dosedependentlyinhibits proliferation of Nalm-6 cells by blocking the cell cycle at G₀/G₁ phase. In addition, FCM showed that ruxolitinib promoted the apoptosis of MLL-BP transfected Nalm-6 cells. Mechanistically, ruxolitinib inactivated JAK/STAT signaling pathway in MLL-BP transfected Nalm-6 cells, mediating ruxolitinib’s inhibition of cell proliferation, and inducing apoptosis. Finally, ruxolitinib significantly inhibited the proliferation of MLL-r ALL cells and promoted their apoptosis. Conclusions: These data provide compelling evidence that ruxolitinib is a promising agent against MLL-r leukemia cell line. However, it needs going through multiple more steps to confirm before it can be an option in clinical practice.