Development of an efficient liposomal DOX delivery formulation for HCC therapy by targeting CK2α.

Hepatocellular carcinoma (HCC) is a digestive tract cancer with high mortality and poor prognosis, especially in China. Current chemotherapeutic drugs lead to poor prognosis, low efficacy, and high side effects due to weak targeting specificity and rapidly formed multidrug resistance (MDR). Based on the previous studies on the doxorubicin (DOX) formulation for cancer targeting therapy, we developed a novel DOX delivery formulation for the targeting chemotherapy of HCC and DOX resistant HCC. HCSP4 was previously screened and casein kinase 2α (CK2α) was predicted as its specific target on HCC cells in our lab. In the study, miR125a-5p was firstly predicted as an MDR inhibiting miRNA, and then CK2α was validated as the target of HCSP4 and miR125a-5p using CK2α-/-HepG2 cells. Based on the above, an HCC targeting and MDR inhibiting DOX delivery liposomal formulation, HCSP4/Lipo-DOX/miR125a-5p was synthesized and tested for its HCC therapeutic efficacy in vitro. The results showed that the liposomal DOX delivery formulation targeted to HCC cells specifically and sensitively, and presented the satisfied therapeutic efficacy for HCC, particularly for DOX resistant HCC. The potential therapeutic mechanism of the DOX delivery formulation was explored, and the formulation inhibited the expression of MDR-relevant genes including ATP-binding cassette subfamily B member 1 (ABCB1, also known as P-glycoprotein), ATP-binding cassette subfamily C member 5 (ABCC5), enhancer of zeste homolog 2 (EZH2), and ATPase Na+/K+ transporting subunit beta 1 (ATP1B1). Our study presents a novel targeting chemotherapeutic drug formulation for the therapy of HCC, especially for drug resistant HCC, although it is primarily and needs further study in vivo, but provided a new strategy for the development of novel anticancer drugs.

CK2 negatively regulates the extinction of remote fear memory.

Cognitive behavioral therapy, rooted in exposure therapy, is currently the primary approach employed in the treatment of anxiety-related conditions, including post-traumatic stress disorder (PTSD). In laboratory settings, fear extinction in animals is a commonly employed technique to investigate exposure therapy; however, the precise mechanisms underlying fear extinction remain elusive. Casein kinase 2 (CK2), which regulates neuroplasticity via phosphorylation of its substrates, has a significant influence in various neurological disorders, such as Alzheimer's disease and Parkinson's disease, as well as in the process of learning and memory. In this study, we adopted a classical Pavlovian fear conditioning model to investigate the involvement of CK2 in remote fear memory extinction and its underlying mechanisms. The results indicated that the activity of CK2 in the medial prefrontal cortex (mPFC) of mice was significantly upregulated after extinction training of remote cued fear memory. Notably, administration of the CK2 inhibitor CX-4945 prior to extinction training facilitated the extinction of remote fear memory. In addition, CX-4945 significantly upregulated the expression of p-ERK1/2 and p-CREB in the mPFC. Our results suggest that CK2 negatively regulates remote fear memory extinction, at least in part, by inhibiting the ERK-CREB pathway. These findings contribute to our understanding of the underlying mechanisms of remote cued fear extinction, thereby offering a theoretical foundation and identifying potential targets for the intervention and treatment of PTSD.

Casein kinase II promotes piRNA production through direct phosphorylation of USTC component TOFU-4.

Piwi-interacting RNAs (piRNAs) are genomically encoded small RNAs that engage Piwi Argonaute proteins to direct mRNA surveillance and transposon silencing. Despite advances in understanding piRNA pathways and functions, how the production of piRNA is regulated remains elusive. Here, using a genetic screen, we identify casein kinase II (CK2) as a factor required for piRNA pathway function. We show that CK2 is required for the localization of PRG-1 and for the proper localization of several factors that comprise the 'upstream sequence transcription complex' (USTC), which is required for piRNA transcription. Loss of CK2 impairs piRNA levels suggesting that CK2 promotes USTC function. We identify the USTC component twenty-one-U fouled-up 4 (TOFU-4) as a direct substrate for CK2. Our findings suggest that phosphorylation of TOFU-4 by CK2 promotes the assembly of USTC and piRNA transcription. Notably, during the aging process, CK2 activity declines, resulting in the disassembly of USTC, decreased piRNA production, and defects in piRNA-mediated gene silencing, including transposons silencing. These findings highlight the significance of posttranslational modification in regulating piRNA biogenesis and its implications for the aging process. Overall, our study provides compelling evidence for the involvement of a posttranslational modification mechanism in the regulation of piRNA biogenesis.

Regulation of cancer progression by CK2: an emerging therapeutic target.

Casein kinase II (CK2) is an enzyme with pleiotropic kinase activity that catalyzes the phosphorylation of lots of substrates, including STAT3, p53, JAK2, PTEN, RELA, and AKT, leading to the regulation of diabetes, cardiovascular diseases, angiogenesis, and tumor progression. CK2 is observed to have high expression in multiple types of cancer, which is associated with poor prognosis. CK2 holds significant importance in the intricate network of pathways involved in promoting cell proliferation, invasion, migration, apoptosis, and tumor growth by multiple pathways such as JAK2/STAT3, PI3K/AKT, ATF4/p21, and HSP90/Cdc37. In addition to the regulation of cancer progression, increasing evidence suggests that CK2 could regulate tumor immune responses by affecting immune cell activity in the tumor microenvironment resulting in the promotion of tumor immune escape. Therefore, inhibition of CK2 is initially proposed as a pivotal candidate for cancer treatment. In this review, we discussed the role of CK2 in cancer progression and tumor therapy.

Inhibition of CK2 Diminishes Fibrotic Scar Formation and Improves Outcomes After Ischemic Stroke via Reducing BRD4 Phosphorylation.

Fibrotic scars play important roles in tissue reconstruction and functional recovery in the late stage of nervous system injury. However, the mechanisms underlying fibrotic scar formation and regulation remain unclear. Casein kinase II (CK2) is a protein kinase that regulates a variety of cellular functions through the phosphorylation of proteins, including bromodomain-containing protein 4 (BRD4). CK2 and BRD4 participate in fibrosis formation in a variety of tissues. However, whether CK2 affects fibrotic scar formation remains unclear, as do the mechanisms of signal regulation after cerebral ischemic injury. In this study, we assessed whether CK2 could modulate fibrotic scar formation after cerebral ischemic injury through BRD4. Primary meningeal fibroblasts were isolated from neonatal rats and treated with transforming growth factor-ß1 (TGF-ß1), SB431542 (a TGF-ß1 receptor kinase inhibitor) or TBB (a highly potent CK2 inhibitor). Adult SD rats were intraperitoneally injected with TBB to inhibit CK2 after MCAO/R. We found that CK2 expression was increased in vitro in the TGF-ß1-induced fibrosis model and in vivo in the MCAO/R injury model. The TGF-ß1 receptor kinase inhibitor SB431542 decreased CK2 expression in fibroblasts. The CK2 inhibitor TBB reduced the increases in proliferation, migration and activation of fibroblasts caused by TGF-ß1 in vitro, and it inhibited fibrotic scar formation, ameliorated histopathological damage, protected Nissl bodies, decreased infarct volume and alleviated neurological deficits after MCAO/R injury in vivo. Furthermore, CK2 inhibition decreased BRD4 phosphorylation both in vitro and in vivo. The findings of the present study suggested that CK2 may control BRD4 phosphorylation to regulate fibrotic scar formation, to affecting outcomes after ischemic stroke.

Casein kinase 2 complex: a central regulator of multiple pathobiological signaling pathways in Cryptococcus neoformans.

The casein kinase 2 (CK2) complex has garnered extensive attention over the past decades as a potential therapeutic target for diverse human diseases, including cancer, diabetes, and obesity, due to its pivotal roles in eukaryotic growth, differentiation, and metabolic homeostasis. While CK2 is also considered a promising antifungal target, its role in fungal pathogens remains unexplored. In this study, we investigated the functions and regulatory mechanisms of the CK2 complex in Cryptococcus neoformans, a major cause of fungal meningitis. The cryptococcal CK2 complex consists of a single catalytic subunit, Cka1, and two regulatory subunits, Ckb1 and Ckb2. Our findings show that Cka1 plays a primary role as a protein kinase, while Ckb1 and Ckb2 have major and minor regulatory functions, respectively, in growth, cell cycle control, morphogenesis, stress response, antifungal drug resistance, and virulence factor production. Interestingly, triple mutants lacking all three subunits (cka1Δ ckb1Δ ckb2Δ) exhibited more severe phenotypic defects than the cka1Δ mutant alone, suggesting that Ckb1/2 may have Cka1-independent functions. In a murine model of systemic cryptococcosis, cka1Δ and cka1Δ ckb1Δ ckb2Δ mutants showed severely reduced virulence. Transcriptomic, proteomic, and phosphoproteomic analyses further revealed that the CK2 complex controls a wide array of effector proteins involved in transcriptional regulation, cell cycle control, nutrient metabolisms, and stress responses. Most notably, CK2 disruption led to dysregulation of key signaling cascades central to C. neoformans pathogenicity, including the Hog1, Mpk1 MAPKs, cAMP/PKA, and calcium/calcineurin signaling pathways. In summary, our study provides novel insights into the multifaceted roles of the fungal CK2 complex and presents a compelling case for targeting it in the development of new antifungal drugs.IMPORTANCEThe casein kinase 2 (CK2) complex, crucial for eukaryotic growth, differentiation, and metabolic regulation, presents a promising therapeutic target for various human diseases, including cancer, diabetes, and obesity. Its potential as an antifungal target is further highlighted in this study, which explores CK2's functions in C. neoformans, a key fungal meningitis pathogen. The CK2 complex in C. neoformans, comprising the Cka1 catalytic subunit and Ckb1/2 regulatory subunits, is integral to processes like growth, cell cycle, morphogenesis, stress response, drug resistance, and virulence. Our findings of CK2's role in regulating critical signaling pathways, including Hog1, Mpk1 MAPKs, cAMP/PKA, and calcium/calcineurin, underscore its importance in C. neoformans pathogenicity. This study provides valuable insights into the fungal CK2 complex, reinforcing its potential as a target for novel antifungal drug development and pointing out a promising direction for creating new antifungal agents.

Influence of CK2 protein kinase activity on the interaction between Trypanosoma cruzi and its vertebrate and invertebrate hosts.

Chagas disease, endemic from Latin America, is caused by Trypanosoma cruzi and is transmitted by triatomine feces. This parasite undergoes complex morphological changes through its life cycle, promoted by significant changes in signal transduction pathways. The activity of protein kinase CK2 has been described in trypanosomatids. Using a specific peptide and radioactive ATP, we identified CK2 activity on the cellular surface and the cytoplasmic content in Trypanosoma cruzi, apart from the secreted form. Dephosphorylated casein promoted an increase of 48% in the secreted CK2 activity. Total extract of peritoneal macrophages from BALB/c and inactivated human serum promoted an increase of 67% and 36%, respectively, in this activity. The protein secreted by parasites was purified by HPLC and had shown compatibility with the catalytic subunit of mammalian CK2. Incubation of the parasites with CK2 inhibitors, added to the culture medium, prevented their growth. The opposite was observed when CK2 activators were used. Results of interaction between Trypanosoma cruzi and the gut of the vector have revealed that, in the presence of CK2 inhibitors, there is a reduction in the association rate. A similar inhibition profile was seen in the Trypanosoma cruzi-macrophages interaction, confirming the importance of this enzyme in the life cycle of this protozoan.

Effect of histidine protonation state on ligand binding at the ATP-binding site of human protein kinase CK2.

Histidine residues contribute to numerous molecular interactions, owing to their structure with the ionizable aromatic side chain with pKa close to the physiological pH. Herein, we studied how the two histidine residues, His115 and His160 of the catalytic subunit of human protein kinase CK2, affect the binding of the halogenated heterocyclic ligands at the ATP-binding site. Thermodynamic studies on the interaction between five variants of hCK2α (WT protein and four histidine mutants) and three ionizable bromo-benzotriazoles and their conditionally non-ionizable benzimidazole counterparts were performed with nanoDSF, MST, and ITC. The results allowed us to identify the contribution of interactions involving the particular histidine residues to ligand binding. We showed that despite the well-documented hydrogen bonding/salt bridge formation dragging the anionic ligands towards Lys68, the protonated His160 also contributes to the binding of such ligands by long-range electrostatic interactions. Simultaneously, His 115 indirectly affects ligand binding, placing the hinge region in open/closed conformations.

Casein kinase 2 activity is a host restriction factor for AAV transduction.

So far, the mechanisms that impede AAV transduction, especially in the human heart, are poorly understood, hampering the introduction of new, effective gene therapy strategies. Therefore, the aim of this study was to identify and overcome the main cellular barriers to successful transduction in the heart, using induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iPSC-CMs), iPSC-derived cardiac fibroblasts (iPSC-CFs), and primary endothelial cells to model vector-host interactions. Through phosphoproteome analysis we established that casein kinase 2 (CK2) signaling is one of the most significantly affected pathways upon AAV exposure. Transient inhibition of CK2 activity substantially enhanced the transduction rate of AAV2, AAV6, and AAV9 in all tested cell types. In particular, CK2 inhibition improved the trafficking of AAVs through the cytoplasm, impaired DNA damage response through destabilization of MRE11, and altered the RNA processing pathways, which were also highly responsive to AAV transduction. Also, it augmented transgene expression in already transduced iPSC-CFs, which retain AAV genomes in a functional, but probably silent form. In summary, the present study provides new insights into the current understanding of the host-AAV vector interaction, identifying CK2 activity as a key barrier to efficient transduction and transgene expression, which may translate to improving the outcome of AAV-based therapies in the future.

Protein Kinase CK2α', More than a Backup of CK2α.

The serine/threonine protein kinase CK2 is implicated in the regulation of fundamental processes in eukaryotic cells. CK2 consists of two catalytic α or α' isoforms and two regulatory CK2ß subunits. These three proteins exist in a free form, bound to other cellular proteins, as tetrameric holoenzymes composed of CK2α2/ß2, CK2αα'/ß2, or CK2α'2/ß2 as well as in higher molecular forms of the tetramers. The catalytic domains of CK2α and CK2α' share a 90% identity. As CK2α contains a unique C-terminal sequence. Both proteins function as protein kinases. These properties raised the question of whether both isoforms are just backups of each other or whether they are regulated differently and may then function in an isoform-specific manner. The present review provides observations that the regulation of both CK2α isoforms is partly different concerning the subcellular localization, post-translational modifications, and aggregation. Up to now, there are only a few isoform-specific cellular binding partners. The expression of both CK2α isoforms seems to vary in different cell lines, in tissues, in the cell cycle, and with differentiation. There are different reports about the expression and the functions of the CK2α isoforms in tumor cells and tissues. In many cases, a cell-type-specific expression and function is known, which raises the question about cell-specific regulators of both isoforms. Another future challenge is the identification or design of CK2α'-specific inhibitors.

A CK2 and SUMO-dependent, PML NB-involved regulatory mechanism controlling BLM ubiquitination and G-quadruplex resolution.

The Boom syndrome helicase (BLM) unwinds a variety of DNA structures such as Guanine (G)-quadruplex. Here we reveal a role of RNF111/Arkadia and its paralog ARKL1, as well as Promyelocytic Leukemia Nuclear Bodies (PML NBs), in the regulation of ubiquitination and control of BLM protein levels. RNF111 exhibits a non-canonical SUMO targeted E3 ligase (STUBL) activity targeting BLM ubiquitination in PML NBs. ARKL1 promotes RNF111 localization to PML NBs through SUMO-interacting motif (SIM) interaction with SUMOylated RNF111, which is regulated by casein kinase 2 (CK2) phosphorylation of ARKL1 at a serine residue near the ARKL1 SIM domain. Upregulated BLM in ARKL1 or RNF111-deficient cells leads to a decrease of G-quadruplex levels in the nucleus. These results demonstrate that a CK2- and RNF111-ARKL1-dependent regulation of BLM in PML NBs plays a critical role in controlling BLM protein levels for the regulation of G-quadruplex.

CK2 inhibitor CX4945 inhibits collagen degradation of HaCaT human keratinocyte cells via attenuation of MMP-1 secretion.

INTRODUCTION: During skin aging, the extracellular matrix (ECM) concomitantly breaks down. Out of the various protein components that comprise ECM, collagen is the most abundant one. Matrix metalloproteinase-1 (MMP-1) is a major collagenase that can degrade collagen. Therefore, the inhibition of MMP-1 may be critical for skin aging prevention. CX4945 is an inhibitor of casein kinase 2 and shows anticancer effects on various types of cancer cells. METHODS AND RESULTS: In this report, we investigated the MMP-1-inhibiting effect of CX4945 in HaCaT human keratinocyte cells. We performed zymography assays, Western blot analysis and immunoprecipitation assay to investigate the anti-MMP-1 effects of CX4945. CX4945 was found to inhibit collagen degradation via attenuation of the MMP-1 secretion out of HaCaT cells. This activity of CX4945 may be mediated by the induction of MMP-1 ubiquitylation via c-Jun N-terminal kinase (JNK) signaling. In wound healing cell migration assay, CX4945 also showed suppressive effect on the migration of HaCaT cells. This finding was closely related to the attenuation of CREB transcription factor via the downregulation of ERK mitogen-activated protein kinase as observed in Western blot analysis. CONCLUSION: Our report suggests that the inhibitory effects of CX4945 on MMP-1 in epidermal cells may offer a basis for further studying its therapeutic potential as an anti-wrinkle agent.

Design, Synthesis and Structure-Activity Relationship Studies of Protein Kinase CK2 Inhibitors Containing a Purine Scaffold.

Protein kinase CK2 (CK2) is involved in the suppression of gene expression, protein synthesis, cell proliferation, and apoptosis, thus making it a target protein for the development of therapeutics toward cancer, nephritis, and coronavirus disease 2019. Using the solvent dipole ordering-based method for virtual screening, we identified and designed new candidate CK2α inhibitors containing purine scaffolds. Virtual docking experiments supported by experimental structure-activity relationship studies identified the importance of the 4-carboxyphenyl group at the 2-position, a carboxamide group at the 6-position, and an electron-rich phenyl group at the 9-position of the purine scaffold. Docking studies based on the crystal structures of CK2α and inhibitor (PDBID: 5B0X) successfully predicted the binding mode of 4-(6-carbamoyl-8-oxo-9-phenyl-8,9-dihydro-7H-purin-2-yl) benzoic acid (11), and the results were used to design stronger small molecule targets for CK2α inhibition. Interaction energy analysis suggested that 11 bound around the hinge region without the water molecule (W1) near Trp176 and Glu81 that is frequently reported in crystal structures of CK2α inhibitor complexes. X-ray crystallographic data for 11 bound to CK2α was in very good agreement with the docking experiments, and consistent with activity. From the structure-activity relationship (SAR) studies presented here, 4-(6-Carbamoyl-9-(4-(dimethylamino)phenyl)-8-oxo-8,9-dihydro-7H-purin-2-yl) benzoic acid (12) was identified as an improved active purine-based CK2α inhibitor with an IC50 of 4.3 µM. These active compounds with an unusual binding mode are expected to inspire new CK2α inhibitors and the development of therapeutics targeting CK2 inhibition.

Rapid phosphorylation of glucose-6-phosphate dehydrogenase by casein kinase 2 sustains redox homeostasis under ionizing radiation.

Exposure to ionizing radiation leads to oxidative damages in living cells. NADPH provides the indispensable reducing power to regenerate the reduced glutathione to maintain cellular redox equilibria. In mammalian cells, pentose phosphate pathway (PPP) is the major route to produce NADPH by using glycolytic intermediates, and the rate-limiting step of PPP is controlled by glucose-6-phosphate dehydrogenase (G6PD). Nevertheless, whether G6PD is timely co-opted under ionizing radiation to cope with oxidative stress remains elusive. Here we show that cellular G6PD activity is induced 30 min after ionizing radiation, while its protein expression is mostly unchanged. Mechanistically, casein kinase 2 (CK2) phosphorylates G6PD T145 under ionizing radiation, which consolidates the enzymatic activity of G6PD by facilitating G6PD binding with its substrate NADP+. Further, CK2-dependent G6PD T145 phosphorylation promotes NADPH production, decreases ROS level and supports cell proliferation under ionizing radiation. Our findings report a new anti-oxidative signaling route under ionizing radiation, by which CK2-mediated rapid activation of G6PD orchestrates NADPH synthesis to maintain redox homeostasis, thereby highlighting its potential value in the early treatment of ionizing radiation-induced injuries.

Structure-guided discovery of adenosine triphosphate-competitive casein kinase 2 inhibitors.

Casein kinase 2 (CK2) is a ubiquitous, highly pleiotropic serine-threonine kinase. CK2 has been identified as a potential drug target for the treatment of cancer and related disorders. Several adenosine triphosphate-competitive CK2 inhibitors have been identified and have progressed at different levels of clinical trials. This review presents details of CK2 protein, structural insights into adenosine triphosphate binding pocket, current clinical trial candidates and their analogues. Further, it includes the emerging structure-based drug design approaches, chemistry, structure-activity relationship and biological screening of potent and selective CK2 inhibitors. The authors tabulated the details of CK2 co-crystal structures because these co-crystal structures facilitated the structure-guided discovery of CK2 inhibitors. The narrow hinge pocket compared with related kinases provides useful insights into the discovery of CK2 inhibitors.

CSNK2A1-mediated MAX phosphorylation upregulates HMGB1 and IL-6 expression in cholangiocarcinoma progression.

BACKGROUND: We established a novel diethylnitrosamine (DEN) -induced mouse model that reflected the progression of cholangiocarcinoma (CCA) from atypical cystic hyperplasia. METHODS: BALB/c mice were administered DEN by oral gavage. Cells isolated from livers were analyzed for expression of CSNK2A1, MAX and MAX-interacting proteins. Human CCA cell lines (MzChA-1, HuCCT1), normal human cholangiocyte (H69), human hepatic stellate cells (LX-2), macrophages (RAW 264.7), and primary hepatic cells were used for cellular and molecular biology assays. RESULTS: Expression of MAX, CSNK2A1, C-MYC, ß-catenin, HMGB1, and IL-6 was upregulated in hepatic cells from CCA liver tissue. The half-life of MAX is higher in CCA cells, and this favors their proliferation. Overexpression of MAX increased growth, migration, and invasion of MzChA-1, whereas silencing of MAX had the opposite effect. MAX positively regulated IL-6 and HMGB1 through paracrine signaling in HepG2, LX2, and RAW cells and autocrine signaling in MzChA-1 cells. CSNK2A1-mediated MAX phosphorylation shifts MAX-MAX homodimer to C-MYC-MAX and ß-catenin-MAX heterodimers and increases the HMGB1 and IL-6 promoter activities. Increase of MAX phosphorylation promotes cell proliferation, migration, invasion, and cholangiocarcinogenesis. The casein kinase 2 inhibitor CX-4945 induces cell cycle arrest and inhibits cell proliferation, migration, invasion, and carcinogenesis in MzChA-1 cells through the downregulation of CSNK2A1, MAX, and MAX-interaction proteins. CONCLUSION: C-MYC-MAX and ß-catenin-MAX binding to E-box site or ß-catenin-MAX bound to TCFs/LEF1 enhanced HMGB1 or IL-6 promoter activities, respectively. IL-6 and HMGB1 secreted by hepatocytes, HSCs, and KCs exert paracrine effects on cholangiocytes to promote cell growth, migration, and invasion and lead to the progression of cholangiocarcinogenesis. CX-4945 provides perspectives on therapeutic strategies to attenuate progression from atypical cystic hyperplasia to cholangiocarcinogenesis.

lncSNHG3 drives breast cancer progression by epigenetically increasing CSNK2A1 expression level.

Mounting evidence demonstrates that long noncoding RNAs (lncRNAs) have critical roles in the initiation and progression of cancer. Here, we report that small nucleolar RNA host gene 3 (SNHG3) is a key regulator of breast cancer progression. We analyzed RNA sequencing data to explore abnormally expressed lncRNAs in breast cancer. The effects of SNHG3 on breast cancer were investigated via in vitro and in vivo assays (CCK-8 assay, colony formation assay, flow cytometry assay, EdU assay, xenograft model, immunohistochemistry, and Western blot). The mechanism of SNHG3 action was explored through bioinformatics, RNA fluorescence in situ hybridization, luciferase reporter assay, RNA pull-down assay, chromatin immunoprecipitation assay and RNA immunoprecipitation assay. We found that SNHG3 expression was upregulated in breast cancer tissues and that its high expression level was associated with poor survival. We also found that high SNHG3 expression was partly induced by STAT3. Moreover, SNHG3 knockdown significantly repressed breast cancer cell growth both in vitro and in vivo. In the cytoplasm, SNHG3 facilitated the expression of Casein kinase II-A1 (CSNK2A1) by absorbing miR-485-5p and recruiting the HuR protein, participating in the malignant progression of breast cancer. Taken together, our study reveals a SNHG3-based regulatory network, which plays an oncogenic role in breast cancer and suggests that SNHG3 may serve as a potential target for the diagnosis and treatment of breast cancer.

DEAD box RNA helicases act as nucleotide exchange factors for casein kinase 2.

DDX RNA helicases promote RNA processing, but DDX3X also activates casein kinase 1 (CK1ε). We show that other DDX proteins also stimulate the protein kinase activity of CK1ε and that this extends to casein kinase 2 (CK2). CK2 enzymatic activity was stimulated by various DDX proteins at high substrate concentrations. DDX1, DDX24, DDX41, and DDX54 were required for full kinase activity in vitro and in Xenopus embryos. Mutational analysis of DDX3X indicated that CK1 and CK2 kinase stimulation engages its RNA binding but not catalytic motifs. Mathematical modeling of enzyme kinetics and stopped-flow spectroscopy showed that DDX proteins function as nucleotide exchange factors toward CK2 and reduce unproductive reaction intermediates and substrate inhibition. Our study reveals protein kinase stimulation by nucleotide exchange as important for kinase regulation and as a generic function of DDX proteins.

CK2 inhibitor DMAT ameliorates spinal cord injury by increasing autophagy and inducing anti-inflammatory microglial polarization.

Spinal cord injury (SCI) is a destructive and disabling nerve injury from which complete recovery has not yet been achieved due to complex pathology. Casein kinase II (CK2) is a pleiotropic serine/threonine protein kinase that plays an essential role in the nervous system. This study aimed to investigate the role of CK2 in SCI to understand the pathogenesis of SCI and explore new therapeutic methods. The SCI rat model of C5 unilateral clamp was established by modified clamp method in male adult SD rats. Then, CK2 inhibitor DMAT was used to treat SCI rats, and the behaviour, pathological changes in the spinal cord and microglial polarization were analysed. Additionally, the effects of DMAT on the polarization and autophagy of microglial BV-2 cells were investigated in vitro, and the effects of BV-2 polarization on spinal cord neuronal cells were analysed by Transwell coculture. Results showed that DMAT significantly increased the BBB score, improved histopathological injury, decreased the expression of inflammatory cytokines, and promoted M2 polarization of microglia in SCI rats. In vitro experiments further confirmed that DMAT could promote the polarization of BV-2 to the M2 type, promote autophagy, and reverse the LPS-induced decline in cell viability and increase in apoptosis of neuronal cells. The use of 3-MA confirmed that autophagy plays an important role in DMAT promoting M2 polarization of BV-2 to improve neuronal cell viability. In conclusion, CK2 inhibitor DMAT improved SCI by inducing anti-inflammatory polarization of microglia through autophagy and is a potential therapeutic target for SCI.

Protein Kinase CK2 Promotes Proliferation, Abnormal Differentiation, and Proinflammatory Cytokine Production of Keratinocytes via Regulation of STAT3 and Akt Pathways in Psoriasis.

Protein kinase CK2 is a constitutively active and ubiquitously expressed serine/threonine kinase that is closely associated with various types of cancers, autoimmune disorders, and inflammation. However, the role of CK2 in psoriasis remains unknown. Herein, the study indicated elevated expression of CK2 in skin lesions from patients with psoriasis and from psoriasis-like mice. In the psoriasis-like mouse model, the CK2-specific inhibitor CX-4945 ameliorated imiquimod-induced psoriasis symptoms with reduced proliferation, abnormal differentiation, inflammatory cytokine production (especially IL-17A) of keratinocytes, and infiltration of γδ T cells. In in vitro studies, exogenous CK2 promoted hyperproliferation and abnormal differentiation of human keratinocytes, which were reversed by the suppression of CK2 with CX-4945 or siRNA. Furthermore, knockdown of CK2 reduced IL-17A expression and abolished IL-17A-induced proliferation and inflammatory cytokine expression in keratinocytes. Interestingly, IL-17A increased the expression of CK2 in keratinocytes, thereby establishing a positive feedback loop. In addition, suppression of CK2 inhibited the activation of STAT3 and Akt signaling pathways in human keratinocytes and imiquimod-induced psoriatic lesions of mice. These findings indicate that a highly expressed CK2 level in the skin lesions is required in the development of psoriasis by promoting epidermal hyperplasia, abnormal differentiation, and inflammatory response via regulation of the STAT3 and Akt signaling pathways. CK2 may be a target for the treatment of psoriasis.