casein-kinase-ii and Lung-Neoplasms

Cisplatin is a platinum agent used in the treatment of non-small cell lung cancer (NSCLC). Much remains unknown regarding the basic operative mechanisms underlying cisplatin resistance in NSCLC. In this study, we found that phosphorylation of IGFBP-3 by CK2 (P-IGFBP-3) decreased its binding to hyaluronan (HA) but not to IGF-1 and rendered the protein less effective at reducing cell viability or increasing apoptosis than the non-phosphorylated protein with or without cisplatin in the human NSCLC cell lines, A549 and H1299. Our data suggest that blocking CD44 signaling augmented the effects of cisplatin and that IGFBP-3 was more effective at inhibiting HA-CD44 signaling than P-IGFBP-3. Blocking CK2 activity and HA-CD44 signaling increased cisplatin sensitivity and more effectively blocked the PI3K and AKT activities and the phospho/total NFκB ratio and led to increased p53 activation in A549 cells. Increased cell sensitivity to cisplatin was observed upon co-treatment with inhibitors targeted against PI3K, AKT, and NFκB while blocking p53 activity decreased A549 cell sensitivity to cisplatin. Our findings shed light on a novel mechanism employed by CK2 in phosphorylating IGFBP-3 and increasing cisplatin resistance in NSCLC. Blocking phosphorylation of IGFBP-3 by CK2 may be an effective strategy to increase NSCLC sensitivity to cisplatin.

Topics: Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cell Survival; Cisplatin; Humans; Hyaluronan Receptors; Hyaluronic Acid; Insulin-Like Growth Factor Binding Protein 3; Lung Neoplasms; Phosphatidylinositol 3-Kinases; Phosphorylation; Proto-Oncogene Proteins c-akt; Tumor Suppressor Protein p53

Immune cells can protect against tumor progression by killing cancer cells, while aberrant expression of the immune checkpoint protein PD-L1 (programmed death ligand 1) in cancer cells facilitates tumor immune escape and inhibits anti-tumor immunotherapy. As a serine/threonine kinase, CK2 (casein kinase 2) regulates tumor progression by multiple pathways, while it is still unclear the effect of CK2 on tumor immune escape. Here it is found that ING4 induced PD-L1 autophagic degradation and inhibites non-small cell lung cancer (NSCLC) immune escape by increasing T cell activity. However, clinical analysis suggests that high expression of CK2 correlates with low ING4 protein level in NSCLC. Further analysis shows that CK2 induce ING4-S150 phosphorylation leading to ING4 ubiquitination and degradation by JFK ubiquitin ligase. In contrast, CK2 gene knockout increases ING4 protein stability and T cell activity, subsequently, inhibites NSCLC immune escape. Furthermore, the combined CK2 inhibitor with PD-1 antibody effectively enhances antitumor immunotherapy. These findings provide a novel strategy for cancer immunotherapy.

Topics: B7-H1 Antigen; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cell Cycle Proteins; Homeodomain Proteins; Humans; Immunotherapy; Lung Neoplasms; Tumor Suppressor Proteins

We have previously reported that a new intronless gene for casein kinase 2α (CK2α), CSNK2A3, is expressed in human cells. The promoter of the well-known CK2α, CSNK2A1, displays characteristics of a housekeeping gene, whereas CSNK2A3 has a characteristic of a regulated promoter with two TATA boxes and a CAAT box. GPR68, a family of the G protein-coupled receptors, is also known as ovarian cancer G protein-coupled receptor 1 (OGR1). In the current study, we analyzed the roles of CK2α genes and neutral endopeptidase (NEP), a key enzyme that influences a variety of malignancies, in the OGR1-induced inhibition of A549 cell migration.. We analyzed the transcript expressions of both the CK2α genes (CSNK2A1 and CSNK2A3) and NEP upon OGR1 overexpression. Protein expression of CK2α and NEP were also analyzed. We further elucidated the functional roles of both CK2α and NEP in the OGR1-induced inhibition of A549 cell migration in vitro using a wound-healing assay. We also analyzed the molecular mechanisms involved in the OGR1-induced inhibition of lung cancer cell migration.. The findings of this study showed that OGR1 upregulated the expression of CSNK2A3 but not CSNK2A1 in the A549 cells. The findings further suggested OGR1 also upregulates the expression of NEP. The OGR1-induced inhibition of A549 cell migration was abrogated completely by inhibition of CK2α activity, whereas partial abrogation (~ 30%) was observed in the presence of NEP inhibition. The results also revealed that OGR1 regulates CSNK2A3 via activation of Rac1/cdc42 and MAPKs pathways. CK2 is ubiquitously expressed, and in contrast, is believed to be a constitutively active enzyme, and its regulation appears to be independent of known second messengers.. In the current study, we report for the first time the OGR1-induced regulation of CSNK2A3, CK2αP, and NEP in A549 cancer cells. Our study also decoded the downstream cellular proteins of OGR1 as well as the molecular mechanism involved in OGR1-induced inhibition of A549 cell migration. The findings of this research suggest the potential therapeutic targets to inhibit lung cancer progression.

Topics: A549 Cells; Casein Kinase II; Cell Line, Tumor; Cell Movement; Female; Humans; Lung Neoplasms; Neprilysin; Ovarian Neoplasms; Receptors, G-Protein-Coupled; Up-Regulation

Casein-kinase CK2 is a Ser/Thr protein kinase that fosters cell survival and proliferation of malignant cells. The CK2 holoenzyme, formed by the association of two catalytic alpha/alpha' (CK2α/CK2α') and two regulatory beta subunits (CK2β), phosphorylates diverse intracellular proteins partaking in key cellular processes. A handful of such CK2 substrates have been identified as targets for the substrate-binding anticancer peptide CIGB-300. However, since CK2β also contains a CK2 phosphorylation consensus motif, this peptide may also directly impinge on CK2 enzymatic activity, thus globally modifying the CK2-dependent phosphoproteome. To address such a possibility, firstly, we evaluated the potential interaction of CIGB-300 with CK2 subunits, both in cell-free assays and cellular lysates, as well as its effect on CK2 enzymatic activity. Then, we performed a phosphoproteomic survey focusing on early inhibitory events triggered by CIGB-300 and identified those CK2 substrates significantly inhibited along with disturbed cellular processes. Altogether, we provided here the first evidence for a direct impairment of CK2 enzymatic activity by CIGB-300. Of note, both CK2-mediated inhibitory mechanisms of this anticancer peptide (i.e., substrate- and enzyme-binding mechanism) may run in parallel in tumor cells and help to explain the different anti-neoplastic effects exerted by CIGB-300 in preclinical cancer models.

Topics: Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Catalytic Domain; Cell Line, Tumor; Cell-Free System; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Microscopy, Fluorescence; Peptides, Cyclic; Phosphorylation; Protein Binding; Proteome; Recombinant Proteins

The EGFR tyrosine kinase inhibitor gefitinib is commonly used for lung cancer patients. However, some patients eventually become resistant to gefitinib and develop progressive disease. Here, we indicate that ecto-ATP synthase, which ectopically translocated from mitochondrial inner membrane to plasma membrane, is considered as a potential therapeutic target for drug-resistant cells. Quantitative multi-omics profiling reveals that ecto-ATP synthase inhibitor mediates CK2-dependent phosphorylation of DNA topoisomerase IIα (topo IIα) at serine 1106 and subsequently increases the expression of long noncoding RNA, GAS5. Additionally, we also determine that downstream of GAS5, p53 pathway, is activated by ecto-ATP synthase inhibitor for regulation of programed cell death. Interestingly, GAS5-proteins interactomic profiling elucidates that GAS5 associates with topo IIα and subsequently enhancing the phosphorylation level of topo IIα. Taken together, our findings suggest that ecto-ATP synthase blockade is an effective therapeutic strategy via regulation of CK2/phospho-topo IIα/GAS5 network in gefitinib-resistant lung cancer cells.

Topics: Antineoplastic Agents; Apoptosis; ATP Synthetase Complexes; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cell Line, Tumor; Cell Membrane; Cell Proliferation; Cell Survival; DNA Topoisomerases, Type II; Drug Resistance, Neoplasm; Gefitinib; Gene Ontology; Humans; Immunohistochemistry; Lung Neoplasms; Oligonucleotide Array Sequence Analysis; Phosphorylation; Protein Kinase Inhibitors; Proteomics; RNA, Long Noncoding; RNA, Small Interfering; Signal Transduction; Tandem Mass Spectrometry; Tumor Suppressor Protein p53

CK2 is a serine/threonine kinase that is overexpressed in breast cancer and its inhibition is associated to reduced tumor growth and disease progression. CIGB-300 is an antitumor peptide with a novel mechanism of action, since it binds to protein kinase CK2 catalytic subunit alpha and to CK2 substrates thus preventing the enzyme activity. Our aim was to evaluate the potential therapeutic benefits of CIGB-300 on breast cancer disease using experimental models with translational relevance. We demonstrated that CIGB-300 reduces breast cancer cell growth in MDA-MB-231, MCF-7 and F3II cells, exerting a pro-apoptotic action and cell cycle arrest. We also found that CIGB-300 decreased cell adhesion, migration and clonogenic capacity of malignant cells. Effect on experimental breast cancer lung metastasis was evaluated after surgical removal of primary F3II tumors or after tail vein injection of tumor cells, also we evaluated CIGB-300 effect on spontaneous lung metastasis in an orthotopic model. Systemic CIGB-300 treatment inhibited breast cancer colonization of the lung, reducing the size and number of metastatic lesions. The present preclinical study establishes for the first time the efficacy of CIGB-300 on breast cancer. These encouraging results suggest that CIGB-300 could be used for the management of breast cancer as an adjuvant therapy after surgery, limiting tumor metastatic spread and thus protecting the patient from distant recurrence.

Topics: Animals; Antineoplastic Agents; Apoptosis; Breast Neoplasms; Casein Kinase II; Cell Line, Tumor; Cell Proliferation; Female; Humans; Lung Neoplasms; MCF-7 Cells; Mice, Inbred BALB C; Neoplasm Invasiveness; Peptides, Cyclic; Protein Kinase Inhibitors

Tumor microenvironment (TME) plays a vital role in determining the outcomes of radiotherapy. As an important component of TME, vascular endothelial cells are involved in the perivascular resistance niche (PVRN), which is formed by inflammation or cytokine production induced by ionizing radiation (IR). Protein kinase CK2 is a constitutively active serine/threonine kinase which plays a vital role in cell proliferation and inflammation. In this study, we investigated the potential role of CK2 in PVRN after IR exposure.. Specific CK2 inhibitors, Quinalizarin and CX-4945, were employed to effectively suppressed the kinase activity of CK2 in human umbilical vein endothelial cells (HUVECs) without affecting their viability. Results showing that conditioned medium from IR-exposed HUVECs increased cell viability of A549 and H460 cells, and the pretreatment of CK2 inhibitors slowed down such increment. The secretion of IL-8 and IL-6 in HUVECs was induced after exposure with IR, but significantly inhibited by the addition of CK2 inhibitors. Furthermore, IR exposure elevated the nuclear phosphorylated factor-κB (NF-κB) p65 expression in HUVECs, which was a master factor regulating cytokine production. But when pretreated with CK2 inhibitors, such elevation was significantly suppressed.. This study indicated that protein kinase CK2 is involved in the key process of the IR induced perivascular resistant niche, namely cytokine production, by endothelial cells, which finally led to radioresistance of non-small cell lung cancer cells. Thus, the inhibition of CK2 may be a promising way to improve the outcomes of radiation in non-small cell lung cancer cells.

Topics: Anthraquinones; Blotting, Western; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cytokines; Endothelial Cells; Endothelium, Vascular; Humans; Lung Neoplasms; Naphthyridines; Phenazines; Protein Kinase Inhibitors

The abnormal activation of the downstream signaling pathways of epidermal growth factor receptor (EGFR) that are independent of EGFR, contribute to the acquisition of EGFR‑tyrosine kinase inhibitor (TKI) resistance in non‑small cell lung cancer (NSCLC). The serine/threonine protein kinase casein kinase II (CK2) phosphorylates and modulates several members of the EGFR downstream signaling pathways. Thus, the purpose of the current study was to investigate the effects of the addition of quinalizarin (a specific CK2 inhibitor) to icotinib (an EGFR‑TKI) on the proliferation and apoptosis of four NSCLC cell lines and its underlying mechanisms. The human lung adenocarcinoma cell lines HCC827, A549, H1650 and H1975 were employed to represent the EGFR‑TKI‑sensitive EGFR (EGFR‑sensitive) mutation, wild‑type EGFR and the EGFR‑TKI‑resistant EGFR (EGFR‑resistant) mutations. The cell viability was determined by the MTT assay. Cell apoptosis was detected by flow cytometry using the Annexin V‑enhanced green fluorescent protein Apoptosis Detection kit. The level of proteins in the EGFR downstream pathway was observed using a western blot assay. The results showed that the cells with the EGFR‑sensitive mutation (HCC827, EGFR E716‑A750del) were more sensitive to icotinib compared with those possessing the EGFR wild‑type (A549) and the EGFR‑resistant mutations (H1650, EGFR E716‑A750del and PTEN lost; H1975, EGFR L858R+T790M). Quinalizarin inhibited proliferation and promoted apoptosis in the cells with the EGFR wild‑type and resistant mutations, and the addition of quinalizarin to icotinib partially restored their sensitivity to icotinib. Quinalizarin and/or icotinib increased the apoptotic rates in the EGFR‑TKI resistant cells, and the combination of these reduced the level of protein downstream of EGFR, including phosphorylated (p‑AKT) and p‑(ERK). In conclusion, quinalizarin may partially sensitize cells to icotinib by inhibiting proliferation and promoting apoptosis mediated by AKT and ERK in EGFR‑TKI resistant NSCLC cell lines.

Topics: Adenocarcinoma of Lung; Anthraquinones; Antineoplastic Agents; Apoptosis; Casein Kinase II; Cell Line, Tumor; Cell Proliferation; Crown Ethers; Drug Resistance, Neoplasm; Humans; Lung Neoplasms; Protein Kinase Inhibitors; Quinazolines

Protein kinase CK2 is a ubiquitously expressed kinase in eukaryotes, which is known to phosphorylate many protein substrates. Because CK2 is involved in the regulation of various signaling pathways, we wondered whether CK2 participated in the regulation of ionizing radiation (IR) induced biological process. In this study, we investigated the effect of IR on the subcellular localization and kinase activity in human non-small cell lung cancer (NSCLC) cells. Immunofluorescent results showed that CK2 subunits shuttle into the nucleus mostly beginning 1 h after IR and lasting more than 6 h. We also conducted in vitro kinase assay and observed an increase in CK2 kinase activity at 6 h after IR. Furthermore, an increase in S phase was observed at 6 h after IR. Colony formation assay results demonstrated that CK2 inhibitor CX-4945 significantly enhanced the effect of irradiation in NSCLC cells. These results indicated that CK2 may be implicated in the regulation of IR-induced biological process.

Topics: Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cell Cycle; Cell Line, Tumor; Cell Nucleus; Cell Survival; Cytoplasm; Cytosol; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Genotype; Humans; Lung Neoplasms; Naphthyridines; Phenazines; Phosphorylation; Radiation, Ionizing; Signal Transduction

Lung cancer is the leading cancer-related death worldwide. Patients with lung cancer mainly died of tumor metastasis and invasion. Protein kinase CK2 is an ubiquitous serine/threonine protein kinase and is frequently upregulated in various human tumors. This study aims to explore the effect and molecular mechanism of the invasion and migration of lung adenocarcinoma A549 cells after knock-down of CK2α expression.. The pSilencerTM 4.1-siCK2α-eGFP of lentiviral-mediated shRNA was constructed. The expression of CK2α was knock-downed, and a stable A549 cell line was established. The invasion and migration of A549 cell line was detected through Transwell and Boyden chamber assays. The protein expression of the PI3K/Akt signaling pathway and mesenchymal-to-epithelial transition (EMT) was evaluated using Western blot analysis.. The invasion and migration of A549 cells were significantly inhibited after the knockdown of CK2α expression compared with that in the control group. p-PTEN, Akt, p-Akt473, p-Akt308, p-PDK1, p-c-Raf, and p-GSK-3β were significantly downregulated, whereas PTEN was upregulated. Moreover, vimentin, β-catenin, Snail, MMP2, and MMP9 were significantly downregulated after reducing the CK2α expression.. CK2α might regulate the invasion and migration of A549 cells through the PI3K/Akt/GSK-3β/Snail signaling pathway, which controls EMT in lung adenocarcinoma.
.. 背景与目的 肺癌已成为全球癌症死亡的首要原因，而侵袭和转移是导致肿瘤死亡的主要原因之一，蛋白激酶CK2是一种高度保守信使非依赖性丝氨酸苏氨酸蛋白激酶，其在各种肿瘤中高表达。本研究旨在探讨下调CK2α基因表达对肺腺癌A549细胞侵袭迁移的影响以及可能的机制。方法 构建pSilencerTM 4.1-shCK2α-eGFP慢病毒表达载体，建立稳定干扰CK2α表达的A549细胞株。利用Transwell和Boyden小室实验检测干扰CK2α表达前后A549细胞的侵袭及迁移的能力。Western blot检测PI3K/Akt信号通路和上皮-间充质转化（mesenchymal-to-epithelial transition, EMT）相关蛋白的表达。结果 与对照组相比，干扰CK2α表达后肺腺癌A549细胞的侵袭及迁移能力明显下降，p-PTEN、Akt、p-Akt473、p-Akt308、 p-PDK1、p-c-Raf、p-GSK-3β蛋白明显下调，PTEN蛋白表达水平显著上调。上皮-间充质转化的相关蛋白E-cadherin蛋白表达水平显著上调，而Vimentin、β-catenin、Snail蛋白表达水平显著下调，与侵袭转移相关蛋白的MMP2、MMP9表达水平显著下调。结论 CK2α可能通过PI3K/Akt/GSK-3β/Snail信号通路来调控上皮-间充质转化参与肺腺癌A549细胞的侵袭及迁移。.

Topics: A549 Cells; Adenocarcinoma; Adenocarcinoma of Lung; Casein Kinase II; Cell Movement; Glycogen Synthase Kinase 3 beta; Humans; Lung Neoplasms; Neoplasm Metastasis; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Signal Transduction

Non-small cell lung carcinoma (NSCLC), a malignancy of lungs, is very aggressive and usually ends up with a dismal prognosis. Cisplatin (CDDP)-based systemic chemotherapy is the main pharmaceutical approach for treating NSCLC, but its effect is discounted by some hitherto unknown reasons. Thus, this study is dedicated to improving the efficacy of CDDP. Our results show that combining use of CDDP with CK2 siRNA or inhibitor is more efficient in suppressing cancer cell growth and promoting apoptosis than use of CDDP alone. The underlying mechanism is that CDDP has two pathways to go: one is that it directly induces apoptosis and the other is that it activates CK2, which suppresses proapoptosis gene promyelocytic leukemia (PML). In conclusion, inhibiting CK2 can enhance sensitivity of CDDP to NSCLC cancer cells through PML.

Topics: A549 Cells; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cisplatin; Humans; Lung Neoplasms; Promyelocytic Leukemia Protein; Protein Kinase Inhibitors; Up-Regulation

N-α-acetyltransferase D (NatD) mediates N-α-terminal acetylation (Nt-acetylation) of histone H4 known to be involved in cell growth. Here we report that NatD promotes the migratory and invasive capabilities of lung cancer cells in vitro and in vivo. Depletion of NatD suppresses the epithelial-to-mesenchymal transition (EMT) of lung cancer cells by directly repressing the expression of transcription factor Slug, a key regulator of EMT. We found that Nt-acetylation of histone H4 antagonizes histone H4 serine 1 phosphorylation (H4S1ph), and that downregulation of Nt-acetylation of histone H4 facilitates CK2α binding to histone H4 in lung cancer cells, resulting in increased H4S1ph and epigenetic reprogramming to suppress Slug transcription to inhibit EMT. Importantly, NatD is commonly upregulated in primary human lung cancer tissues where its expression level correlates with Slug expression, enhanced invasiveness, and poor clinical outcomes. These findings indicate that NatD is a crucial epigenetic modulator of cell invasion during lung cancer progression.NatD is an acetyltransferase responsible for N-α-terminal acetylation of the histone H4 and H2A and has been linked to cell growth. Here the authors show that NatD-mediated acetylation of histone H4 serine 1 competes with the phosphorylation by CK2α at the same residue thus leading to the upregulation of Slug and tumor progression.

Topics: A549 Cells; Adenocarcinoma; Animals; Carcinoma, Squamous Cell; Casein Kinase II; Cell Movement; China; Epithelial-Mesenchymal Transition; Female; HEK293 Cells; Histones; Humans; Lung Neoplasms; Male; Mice; Middle Aged; N-Terminal Acetyltransferase D; Neoplasm Invasiveness; Phosphorylation; Snail Family Transcription Factors

Protein kinase CK2 is a highly conserved protein Ser/Thr protein kinase and plays important roles in cell proliferation, protein translation and cell survival. This study investigated the possibility of using CK2 inhibition as a new approach for increasing the efficacy of radiotherapy in non-small cell lung cancer (NSCLC) and its underlying mechanisms. Kinase inhibition of CK2 was attempted either by using the specific CK2 inhibitor, Quinalizarin or by applying siRNA interference technology to silence the expression of the catalytic subunit of CK2 in A549 and H460 cells. The results showed that CK2α knockdown or Quinalizarin significantly enhanced the radiosensitivity of various NSCLC cells. The notable findings we observed after exposure to both CK2 inhibition and ionizing radiation (IR) were a prolonged delay in radiation-induced DNA double-strand breaks (DSB) repair, robust G2/M checkpoint arrest and increased apoptosis. In vivo studies further demonstrated that compared with each treatment alone, CK2 inhibition combined with IR reduced tumor growth in the H460 cell xenograft model. In conclusion, CK2 is a promising target for the enhancement of radiosensitivity in NSCLC.

Topics: A549 Cells; Animals; Apoptosis; Blotting, Western; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cell Cycle; Cell Line, Tumor; DNA Breaks, Double-Stranded; Female; Flow Cytometry; Humans; Immunohistochemistry; Lung Neoplasms; Mice; Mice, Inbred BALB C; Mice, Nude; Reverse Transcriptase Polymerase Chain Reaction; Xenograft Model Antitumor Assays

Casein kinase 2 (CK2) is overexpressed in several types of cancer. It has more than 300 substrates mainly involved in DNA reparation and replication, chromatin remodeling and cellular growth. In recent years CK2 became an interesting target for anticancer drug development. CIGB-300 is a peptidic inhibitor of CK2 activity, designed to bind to the phospho-acceptor domain of CK2 substrates, impairing the correct phosphorylation by the enzyme. The aim of this work was to explore the antitumor effects of this inhibitor in preclinical lung cancer models.. Human H125 and murine 3LL Lewis lung carcinoma cell lines were used to evaluate the effect of CIGB-300 treatment in vitro. For this purpose, adhesion, migration and invasion capabilities of cancer cells were tested. Proteolytic activity of tumor cell-secreted uPA and MMP after CIGB-300 incubation was also analyzed. In vivo anticancer efficacy of the peptide was evaluated using experimental and spontaneous lung colonization assays in C57BL/6 mice. Finally, in order to test the effect of CIGB-300 on tumor cell-induced angiogenesis, a modified Matrigel plug assay was conducted.. We demonstrate that treatment with low micromolar concentrations of CIGB-300 caused a drastic reduction of adhesion, migration and invasion of lung cancer cells. Reduced invasiveness after CIGB-300 incubation was associated with decreased proteolytic activity of tumor cell-conditioned medium. In vivo, intravenous administration of CIGB-300 (10mg/kg) markly decreased lung colonization and metastasis development of 3LL cells. Interestingly, after 5days of systemic treatment with CIGB-300, tumor cell-driven neovascularization was significantly reduced in comparison to control group. Altogether our data suggest an important role of CK2 in lung tumor development, suggesting a potential use of CIGB-300 as a novel therapeutic agent against lung cancer.

Topics: Administration, Intravenous; Angiogenesis Inhibitors; Animals; Apoptosis; Casein Kinase II; Cell Line, Tumor; Cell Proliferation; Drug Evaluation, Preclinical; Humans; Lung Neoplasms; Mice; Mice, Inbred C57BL; Neoplasm Metastasis; Neovascularization, Pathologic; Peptides, Cyclic; Phosphorylation

To explore whether quninalizarin, an specific inhibitor of protein kinase CK2, could sensitize icotinib in EGFR-TKIs (epithelial growth factor receptor-tyrosine kinase inhibitor)-resistant cell lines and uncover the underlying mechanisms.. MTT assay was performed to evaluate the inhibitory effect of quninalizarin, icotinib or the combination of both on cell proliferation in several lung adenocarcinoma cell lines. Western blot assay was used to assess if combined inhibition of EGFR and protein kinase CK2 by icotinib and quninalizarin, exerts effect on the expression and phosphorylation of major proteins of EGFR signaling pathways.. The IC50 of HCC827, H1650, H1975 and A549 cells for icotinib were (8.07±2.00)μmol/L, (66.01±6.64)μmol/L, (265.60±9.47)μmol/L and (87.88±6.8)μmol/L, respectively, indicating that HCC827 cells are sensitive to icotinib, and the H1650, H1975 and A549 cells are relatively resistant to icotinib. When treated with both quninalizarin and icotinib in the concentration of 50 μmol/L, the viability of H1650, H1975 and A549 cells was (40.64±3.73)%, (65.74±3.27)% and (44.96±0.48)%, respectively, significantly lower than that of H1650, H1975 and A549 cells treated with 50 μmol/L icotinib alone (55.05±1.22)%, (71.98±1.60)% and (61.74±6.18)%, respectively (P<0.01 for all). When treated with both 100 μmol/L quninalizarin and 100 μmol/L icotinib, the viability of H1650, H1975 and A549 ells were (23.35±0.81)%, (55.70±1.03)%, (33.42±1.33)%, respectively, significantly lower than the viability of H1650, H1975 and A549 cells treated with 100 μmol/L icotinib alone (40.57±2.65)%, (62.40±2.05)% and (44.97±8.20)%, respectively, (P<0.01 for all). The two-way ANOVA analysis showed that compared with the viability of EGFR-TKIs-resistant cells (H1650, H1975, A549) treated with 50 μmol/L and 100 μmol/L icotinib alone, the viability of cells treated with icotinib and quinalizarin were significantly suppressed, and the differences were statistically significant (P<0.01). In addition, the phosphorylation form of Akt and ERK (namely p-Akt and p-ERK) were significantly down-regulated by treating with quninalizarin and icotinib together in the H1650 cells while the expression of Akt and ERK changed little.. Quinalizarin, as a specific CK2 inhibitor, may overcome icotinib resistance by inhibiting proliferation mediated by Akt and ERK in human lung adenocarcinoma cell lines, and enhances the suppressive effect of icotinib on the proliferation of EGFR-TKIs-resistant human lung adenocarcinoma cells.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Analysis of Variance; Anthraquinones; Apoptosis; Casein Kinase II; Cell Line, Tumor; Cell Proliferation; Cell Survival; Crown Ethers; Down-Regulation; Drug Combinations; Drug Resistance, Neoplasm; Drug Synergism; ErbB Receptors; Humans; Lung Neoplasms; Phosphorylation; Protein-Tyrosine Kinases; Quinazolines; Signal Transduction

Breast cancer metastasis suppressor 1 (BRMS1) is decreased in non-small cell lung cancer (NSCLC) and other solid tumors, and its loss correlates with increased metastases. We show that BRMS1 is posttranslationally regulated by TNF-induced casein kinase 2 catalytic subunit (CK2α') phosphorylation of nuclear BRMS1 on serine 30 (S30), resulting in 14-3-3ε-mediated nuclear exportation, increased BRMS1 cytosolic expression, and ubiquitin-proteasome-induced BRMS1 degradation. Using our in vivo orthotopic mouse model of lung cancer metastases, we found that mutation of S30 in BRMS1 or the use of the CK2-specific small-molecule inhibitor CX4945 abrogates CK2α'-induced cell migration and invasion and decreases NSCLC metastasis by 60-fold. Analysis of 160 human NSCLC specimens confirmed that tumor CK2α' and cytoplasmic BRMS1 expression levels are associated with increased tumor recurrence, metastatic foci, and reduced disease-free survival. Collectively, we identify a therapeutically exploitable posttranslational mechanism by which CK2α-mediated degradation of BRMS1 promotes metastases in lung cancer. Cancer Res; 76(9); 2675-86. ©2016 AACR.

Topics: Active Transport, Cell Nucleus; Animals; Blotting, Western; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Disease Models, Animal; Disease-Free Survival; Fluorescent Antibody Technique; Heterografts; Immunohistochemistry; Immunoprecipitation; Kaplan-Meier Estimate; Lung Neoplasms; Mice; Neoplasm Invasiveness; Repressor Proteins; Tissue Array Analysis

Nucleolar protein interacting with the FHA domain of pKi-67 (NIFK) is a Ki-67-interacting protein. However, its precise function in cancer remains largely uninvestigated. Here we show the clinical significance and metastatic mechanism of NIFK in lung cancer. NIFK expression is clinically associated with poor prognosis and metastasis. Furthermore, NIFK enhances Ki-67-dependent proliferation, and promotes migration, invasion in vitro and metastasis in vivo via downregulation of casein kinase 1α (CK1α), a suppressor of pro-metastatic TCF4/β-catenin signaling. Inversely, CK1α is upregulated upon NIFK knockdown. The silencing of CK1α expression in NIFK-silenced cells restores TCF4/β-catenin transcriptional activity, cell migration, and metastasis. Furthermore, RUNX1 is identified as a transcription factor of CSNK1A1 (CK1α) that is negatively regulated by NIFK. Our results demonstrate the prognostic value of NIFK, and suggest that NIFK is required for lung cancer progression via the RUNX1-dependent CK1α repression, which activates TCF4/β-catenin signaling in metastasis and the Ki-67-dependent regulation in cell proliferation.

Topics: Animals; beta Catenin; Casein Kinase II; Cell Proliferation; Disease Models, Animal; Humans; Intracellular Signaling Peptides and Proteins; Ki-67 Antigen; Korea; Lung Neoplasms; Mice; Neoplasm Metastasis; Nuclear Proteins

Protein kinase CK2α is frequently upregulated in different cancers. Alteration of CK2α expression and its activity is sufficient to induce dramatic changes in cell fate. It has been established that CK2α induces oncogenesis through modulation of both AKT and PML. CK2α has been found to be overexpressed in breast cancer. In contrary, statistical reports have shown low level of PML. However, the regulation of CK2α gene expression is not fully understood. In the current study, we found that CK2α and activated AKT positively correlate with ERα, whereas PML follows an inverse correlation in human breast cancer tissues. Modulation of ERα signalling leads to recruitment of activated ERα on the ERE sites of CK2α promoter, resulting in CK2α transactivation. Furthermore, the DMBA induced tumours in rat showed elevated level of active CK2α. Consequently it mediates enhancement of AKT activity and PML degradation, resulting in increased cellular proliferation, migration and metastasis. Syngeneic ERα overexpressing stable mouse 4T1 cells produce larger primary tumours and metastatic lung nodules in mice, corroborating our in vitro findings. Hence, our study provides a novel route of ERα dependent CK2α mediated oncogenesis that causes upregulation and consequent AKT activation along with degradation of tumour suppressor PML.

Topics: Animals; Breast Neoplasms; Carcinogenesis; Carcinogens; Casein Kinase II; Cell Line, Tumor; Estrogen Receptor alpha; Female; Gene Expression Regulation, Neoplastic; HEK293 Cells; Humans; Lung Neoplasms; Mammary Neoplasms, Experimental; MCF-7 Cells; Mice; Mice, Inbred BALB C; Nuclear Proteins; Promoter Regions, Genetic; Promyelocytic Leukemia Protein; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Signal Transduction; Transcription Factors; Transcriptional Activation; Tumor Suppressor Proteins

Nowadays, EGFR-TKIs are important treatment strategy in lung cancer, but the resistance to EGFR-TKIs remains an unsolved issue preventing the patients from further benefits. Recent studies have shown that casein kinase (CK2) plays an important role in carcinogenesis and development of cancer. CK2 inhibitor has also demonstrated anti-tumor effects. Here we reviewed the mechanism of EGFR-TKIs and the potential reasons of resistance. Interestingly, there is a crosstalk between CK2 and EGFR downstream signaling pathways, therefore, it may be possible that CK2 inhibitor can overcome the EGFR-TKIs resistance.

Topics: Casein Kinase II; Drug Resistance, Neoplasm; ErbB Receptors; Humans; Lung Neoplasms; Protein Kinase Inhibitors; Signal Transduction

The response to chemotherapeutic drugs in non-small cell lung cancer (NSCLC) is unsatisfactory, leading to poor outcomes. This study the aimed to investigates anticancer effects of CX-4945, a potent casein kinase II (CK2) inhibitor, in chemorefractory NSCLC cells.. Cell proliferation and apoptosis assay were carried-out by annexin V-FITC and FACScan after drug treatment with paclitaxel, cisplatin and CX-4945. AKT/mTOR and CK2α signals were measured by western blotting. Treatment was carried-out using siRNA to inhibit CK2α.. Paclitaxel, and cisplatin effectively inhibited cell proliferation and induced apoptosis in A549 cells, while not in H1299, Calu-1 and H358 cells. In these chemorefractory cell lines, AKT signalling was maintained despite drug treatment. However, CX-4945 suppressed cell growth, with cell-cycle arrest at G2/M phase and induced apoptosis with an increase of cleaved caspase-3 and PARP1 in a dose-dependent manner. Accordingly, AKT and its downstream signals such as mTOR and p70S6K were down-regulated by CX-4945. Transfection of CK2α siRNA had similar effects to CX-4945 treatment on cell proliferation and apoptosis.. CX-4945 shows a promising anticancer action through down-regulation of AKT/mTOR signals, suggesting its possible application for treatment of chemorefractory lung cancer.

Topics: Apoptosis; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cell Cycle Checkpoints; Cell Line, Tumor; Cisplatin; Down-Regulation; Humans; Lung Neoplasms; Naphthyridines; Paclitaxel; Phenazines; Proto-Oncogene Proteins c-akt; TOR Serine-Threonine Kinases

Here, we demonstrate the possible applications of micropillar arrays in screening anti-metastasis drugs. Human lung adenocarcinoma A549 cells incubated in multiwell plates containing micropillars exhibited markedly different physical/biochemical behavior depending on pillar dimensions. In particular, A549 cells grown in plates containing 2-μm diameter, 16-μm pitched pillar arrays showed epithelial-to-mesenchymal transition (EMT)-like behavior; cell body elongation, and highly increased activation of the focal adhesion kinase (FAK)-Src-paxillin signaling cascade. FAK is the most prominent kinase involved in dynamic regulation of the actin cytoskeleton and cell adhesion, migration, and invasion. Activation of FAK, a hallmark of cancer cell adhesion and migration, is normally induced by various growth factors, such as transforming growth factor-β (TGF-β). Here, we found that pillar-mediated activation of signaling molecules mimicked that induced by TGF-β. Notably, micropillar arrays with specific dimensions accelerated the elongation of cells, an effect linked to the activation of signaling molecules related to EMT. Micropillar-induced FAK activation could be arrested by the casein kinase-2 (CK2) inhibitor CX-4945, a drug candidate with activity against TGF-β-induced cancer cell metastasis, demonstrating the possibility of using inorganic microstructures for cell-based drug screening.. In this work, we have fabricated flexible substrates with regular arrays of micrometersized pillars, and used them to grow A549 human lung adenocarcinoma cells. Cells exhibit dramatically different behavior depending on the intervals of pillars. Especially, cells grown in certain pillar structures show epithelial-to mesenchmal transition (EMT)-like morphology and related molecules, which is similar to the activation obtained using expensive cytokine TGF-β. Based on the fact that pillar arrays may activate EMT like transition, screening of anti-cancer drug using pillar arrays have demonstrated as well in our work. Our study confirms that mechanical stimulation may exert similar effects with chemical stimulation, and such mechanical structures could be used as a large-scale drug screening platforms. Cell morphogenesis on engineered substrate is not new, but the present work could be distinguished with its unique fabrication process that can mass produce the structures and it could be applied for high-throughput drug screening. Also, we suggest the formation of focal adhesions on pillar structures and consequent strain as the possible mechanism behind the observed EMT-like transition. Currently, we are working on full-scale profiling of metabolomics and proteomics of cells grown in large-scale pillar arrays as well.

Topics: Apoptosis; Biological Assay; Casein Kinase II; Cell Line, Tumor; Cell Survival; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Enzyme Activation; Equipment Design; Equipment Failure Analysis; Focal Adhesion Kinase 1; Humans; Lung Neoplasms; Mechanotransduction, Cellular; Naphthyridines; Paxillin; Phenazines; src-Family Kinases; Tissue Array Analysis; Treatment Outcome

Protein kinase CK2 is widely expressed in eukaryotic cells, and plays an important role in cell proliferation, migration, apoptosis, etc. The aim of the current study is to explore how Quinalizarin, a specific CK2 inhibitor, affects the cell proliferation, migration, and apoptosis of different pathological and genetic types of human lung cancer cell lines.. MTT assays were performed to evaluate the cell viability after being treated by Quinalizarin. Transwell migration assays were used to assess whether Quinalizarin could suppress cell migration. Flow cytometry was employed to test the apoptosis rate of different cells.. After being treated by Quinalizarin, the viability of different pathological types of lung cancer cells (H446, H460, A549) were significantly suppressed in a time and dose-dependent manner. More interestingly, in a serial of human lung adenocarcinoma cell lines with different epidermal growth factor receptor (EGFR) mutation status, Quinalizarin was shown to have a much better ability to reduce the viability of cells with EGFR sensitive mutation than those with resistance mutations. Meanwhile, we also found that the cell migration of different pathological types of lung cancer cells (H446, H460, A549) was significantly decreased by Quinalizarin dose-dependently. In addition, the apoptosis rates in those cells were proved to be increased after exposed to Quinalizarin.. Quinalizarin, the specific CK2 inhibitor, could reduce cell viability with emphasis on adenocarcinoma cells harboring EGFR sensitive mutation, suppresses migration, and accelerates apoptosis in different human lung cancer cell lines.

Topics: Adenocarcinoma; Apoptosis; Carcinoma, Large Cell; Casein Kinase II; Cell Movement; Cell Proliferation; Flow Cytometry; Humans; Lung Neoplasms; Quinazolines; Small Cell Lung Carcinoma; Tumor Cells, Cultured

Platelet-activating factor (PAF) promotes tumour metastasis via activation of the transcription factor nuclear factor-κB (NF-κB). We here investigated the role of the protein kinase CK2 (formerly Casein Kinase 2 or II) in PAF-induced NF-κB activation and tumour metastasis, given that PAF has been reported to increase CK2 activity, and that CK2 plays a key role in NF-κB activation. PAF increased CK2 activity, phosphorylation and protein expression in vivo as well as in vitro. CK2 inhibitors inhibited the PAF-mediated NF-κB activation and expression of NF-κB-dependent pro-inflammatory cytokines and anti-apoptotic factors. Pre-treatment with the antioxidant N-Acetyl-L-Cysteine (NAC) resulted in a significant inhibition in PAF-induced enhancement of CK2 activity, phosphorylation and protein expression in vivo as well as in vitro. H2 O2 and known reactive oxygen species inducers, lipopolysaccharide (LPS) and tumour necrosis factor-α (TNF-α) enhanced CK2 activity, phosphorylation and protein expression, which was again inhibited by antioxidant. PAF, LPS and TNF-α induced increased CK2 activity, phosphorylationand protein expression, which were inhibited by p38 inhibitor. PAF, LPS or TNF-α increased pulmonary metastasis of B16F10, which was inhibited by antioxidants, CK2 inhibitor and p38 inhibitor. Our data suggest that (i) reactive oxygen species activate CK2 via p38, which, in turn, induces NF-κB activation, and (ii) PAF, LPS and TNF-α increase pulmonary tumour metastasis via the induction of the reactive oxygen species (ROS)/p38/CK2/NF-κB pathway.

Topics: Animals; Blotting, Western; Casein Kinase II; Disease Models, Animal; Electrophoretic Mobility Shift Assay; Enzyme Activation; Immunohistochemistry; Lung Neoplasms; Mice; Mice, Inbred C57BL; Neoplasm Invasiveness; NF-kappa B; Platelet Activating Factor; Reactive Oxygen Species; Real-Time Polymerase Chain Reaction

Dysfunction of ribosomal proteins (RPs) may play an important role in molecular tumorigenesis, such as lung cancer, acting in extraribosomal functions. Many protein-protein interaction studies and genetic screens have confirmed the extraribosomal capacity of RPs. As reported, ribosomal protein L22 (RPL22) dysfunction could increase cancer risk. In the present study, we examined RPL22-protein complexes in lung cancer cells. Tandem affinity purification (TAP) was used to screen the RPL22-protein complexes, and GST pull-down experiments and confocal microscopy were used to assess the protein-protein interaction. The experiment of kinase assay was used to study the function of the RPL22-protein complexes. The results showed that several differentially expressed proteins were isolated and identified by LC-MS/MS, which revealed that one of the protein complexes included casein kinase 2α (CK2α). RPL22 and CK2α interact in vitro. RPL22 also inhibited CK2α substrate phosphorylation in vitro. This is the first report of the RPL22-CK2α relationship in lung cancer. Dysregulated CK2 may impact cell proliferation and apoptosis, key features of cancer cell biology. Our results indicate that RPL22 may be a candidate anticancer agent due to its CK2α-binding and -inhibitory functions in human lung cancer.

Topics: Apoptosis; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cell Line, Tumor; Cell Proliferation; Gene Expression Regulation, Neoplastic; HEK293 Cells; Humans; Lung Neoplasms; Protein Binding; Ribosomal Proteins; RNA-Binding Proteins; Tandem Mass Spectrometry

The Hedgehog (Hh) signaling pathway has been implicated in stem cell maintenance and its activation is aberrant in several types of cancer including mesothelioma. Protein kinase CK2 affects several cell signaling pathways through the mechanism of phosphorylation.. Protein and mRNA levels of CK2α and Gli1 were tested by quantitative RT-PCR and immunohistochemistry staining in mesothelioma samples and cell lines. Down-regulated Gli1 expression and transcriptional activity were demonstrated by RT-PCR, Western blot and luciferase reporter assay.. In this study, we show that CK2α is over-expressed and a positive regulator of Hegdehog/Gli1 signaling in human malignant pleural mesothelioma. First of all, we found that the mRNA levels of CK2α and Gli1 were broadly elevated and correlated (n = 52, r = 0.401, P < 0.05), compared with LP9 (a normal mesothelial cell line). We then investigated their expression at the protein level, and found that all the 7 mesothelioma cell lines tested showed positive staining in CK2α and Gli1 immunohistochemistry. Correlation analysis by Pearson test for CK2α and Gli1 expression in the 75 mesothelioma tumors and the 7 mesothelioma cell lines showed that the two protein expression was significantly correlated (n = 82, r = 0.554, P < 0.01). Furthermore, we demonstrated that Gli1 expression and transcriptional activity were down-regulated after CK2α was silenced in two mesothelioma cell lines (H28 and H2052). CK2α siRNA also down-regulated the expression of Hh target genes in these cell lines. Moreover, treatment with a small-molecule CK2α inhibitor CX-4945 led to dose-dependent inhibition of Gli1 expression and transcriptional activity. Conversely, forced over-expression of CK2α resulted in an increase in Gli1 transcriptional activity in H28 cells.. Thus, we report for the first time that over-expressed CK2α positively regulate Hh/Gli1 signaling in human mesothelioma.

Topics: Casein Kinase II; Cell Line, Tumor; Dose-Response Relationship, Drug; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Hedgehog Proteins; Humans; Lung Neoplasms; Mesothelioma; Mesothelioma, Malignant; Pleural Neoplasms; Protein Kinase Inhibitors; RNA Interference; Signal Transduction; Transcription Factors; Transcription, Genetic; Transfection; Zinc Finger Protein GLI1

Protein kinase CK2 has diverse functions promoting and maintaining cancer phenotypes. We investigated the effect of CK2 inhibition in lung cancer cells with T790M-mediated resistance to the EGFR-TK inhibitor. Resistant sublines of PC-9 to gefitinib (PC-9/GR) and erlotinib (PC-9/ER) were established by previous study, and T790M secondary mutation was found in both resistant sublines. A decrease of EGFR by siRNA treatment effectively controlled the growth of resistant cells, thus suggesting that they still have EGFR-dependency. CX-4945, a potent and selective CK2 inhibitor, induced autophagy in PC-9/GR and PC-9/ER, and which was supported by the induction of autophagic vacuoles and microtubule-associated protein 1 light chain 3 (LC3) expression, and the increase of punctate fluorescent signals in resistant cells pre-transfected with green fluorescent protein (GFP)-tagged LC3. However, the withdrawal of CX-4945 led to the recovery of cancer cells with autophagy. We found that the induction of autophagy by CX-4945 in both resistant cells was CK2 dependent by using small interfering RNA against CK2. The treatment with CX-4945 alone induced a minimal growth inhibition in resistant cells. However, combined treatment of CX-4945 and EGFR-TKI effectively inhibited cancer-cell proliferation and induced apoptosis. CX-4945 increased the translocation of EGFR from the cell surface into the autophagosome, subsequently leading to the decrease of EGFR while inhibition of autophagy by 3MA or Atg7-targeted siRNA pretreatment reduced the decrease of EGFR by CX-4945. Accordingly, apoptosis by a combination of CX-4945 and EGFR-TKI was suppressed by 3MA or Atg7-targeted siRNA pretreatment, thus suggesting that autophagosome-mediated EGFR down-regulation would have an important role regarding apoptotic cell death by EGFR-TKI. Combined treatment of the CK2 inhibitor and EGFR-TKI may be a promising strategy for overcoming T790M-mediated resistance.

Topics: Apoptosis; Autophagy; Casein Kinase II; Cell Line, Tumor; Drug Resistance, Neoplasm; ErbB Receptors; Erlotinib Hydrochloride; Gefitinib; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Mutation; Naphthyridines; Phagosomes; Phenazines; Protein Kinase Inhibitors; Quinazolines

Cancer is a leading cause of death worldwide. Cancer cells proliferate uncontrollably and, many cases, spread to other parts of the body. A protein historically involved in cancer is protein kinase CK2. CK2 is a serine-threonine kinase that has been involved in cell growth, cell proliferation and cell apoptosis. CK2 functions as an oncogene when overexpressed in mouse tissues, and can synergize with known oncogenes, such as ras, to induce cell transformation in cells in culture. CK2, typically the CK2α protein, is found elevated in a number of human tumors. However, we have little information on CK2α' and CK2β proteins, and scarce information on CK2 gene transcript expression. Here, we explore the expression of CK2 transcripts in primary tumor tissues using the database Oncomine in the six cancers with the highest mortality in the U.S.A. In addition, we studied the correlation between CK2 expression and overall survival using the Kaplan-Meier Plotter database in breast, ovarian, and lung cancers. We found widespread upregulation in the expression of CK2 genes in primary tumor tissues. However, we found underexpression of CK2α' transcripts in some tumors, increased CK2β transcripts in some invasive tumors, and deregulation of CK2 transcripts in some tumor precursors. There was also correlation between CK2 expression levels and patient survival. These data provides additional evidence for CK2 as a biomarker for cancer studies and as a target for cancer therapy.

Topics: Biomarkers, Tumor; Breast Neoplasms; Carcinoma; Casein Kinase II; Female; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Male; Ovarian Neoplasms; Prognosis; RNA, Messenger

Lung cancer is a high-grade malignancy with poor 5 year-survival rates that remains incurable with current therapies. Different cellular stresses, including antitumor agents, ionizing radiation and ultraviolet (UV) light, can induce apoptosis and activate signaling pathways. UV has multiple effects on tumor cells, including DNA damage, and increases the expression of some genes involved in tumor cell apoptosis and DNA repair. It has been reported that UV can also activate casein kinase 2 (CK2). CK2, a Ser/Thr protein kinase, has been reported to be frequently overexpressed in various types of human cancer, including lung cancer, and is associated with tumor development. Thus, combination of UV and CK2 inhibitors may be a new strategy for the treatment of lung cancer. Our results demonstrated that inhibition of CK2a through CK2 siRNA or a CK2 inhibitor [(4,5,6,7-tetrabromobenzotriazole (TBB)] enhances the decrease in cell viability of lung cancer cells (A549 and H2030) induced by UV. Western blot analysis demonstrated that the combination increased the expression of apoptotic protein markers cytochrome c and the cleavage of poly ADP-ribose polymerase (PARP) and caspase-3. Furthermore, our results indicated that UV decreased the expression of the tumor suppressor protein PML through activation of CK2. Inhibition of CK2 by CK2 siRNA and TBB can recover the reduction of PML induced by UV. Collectively, these results demonstrate the significant apoptosis of lung cancer cells induced by combination treatment of the CK2 inhibitor and UV radiation. CK2 enhanced cell apoptosis by UV radiation may due, at least partly, to recover the expression of PML. These findings warrant the clinical testing of CK2 inhibitors which, when used in conjunction with DNA-damaging agents such as radiation, may be an effective cancer therapeutic strategy.

Topics: Apoptosis; Casein Kinase II; Caspase 3; Cell Line, Tumor; Cell Survival; Cytochromes c; Humans; Lung Neoplasms; Nuclear Proteins; Poly(ADP-ribose) Polymerases; Promyelocytic Leukemia Protein; RNA Interference; RNA, Small Interfering; Transcription Factors; Triazoles; Tumor Suppressor Proteins; Ultraviolet Rays

Protein kinase CK2 is frequently elevated in a variety of human cancers. The Notch1 signalling pathway has been implicated in stem cell maintenance and its aberrant activation has been shown in several types of cancer including lung cancer. Here, we show, for the first time, that CK2α is a positive regulator of Notch1 signalling in lung cancer cell lines A549 and H1299. We found that Notch1 protein level was reduced after CK2α silencing. Down-regulation of Notch1 transcriptional activity was demonstrated after the silencing of CK2α in lung cancer cells. Furthermore, small-molecule CK2α inhibitor CX-4945 led to a dose-dependent inhibition of Notch1 transcriptional activity. Conversely, forced overexpression of CK2α resulted in an increase in Notch1 transcriptional activity. Finally, the inhibition of CK2α led to a reduced proportion of stem-like CD44 + /CD24- cell population. Thus, we report that the inhibition of CK2α down-regulates Notch1 signalling and subsequently reduces a cancer stem-like cell population in human lung cancer cells. Our data suggest that CK2α inhibitors may be beneficial to the lung cancer patients with activated Notch1 signalling.

Topics: Casein Kinase II; CD24 Antigen; Cell Line, Tumor; DNA; Dose-Response Relationship, Drug; Down-Regulation; Flow Cytometry; Gene Expression Regulation, Neoplastic; Humans; Hyaluronan Receptors; Immunohistochemistry; Lung Neoplasms; Naphthyridines; Neoplastic Stem Cells; Phenazines; Phenotype; Receptor, Notch1; RNA, Small Interfering; Signal Transduction; Transcription, Genetic

Casein kinase II (CK2) inhibitors suppress cancer cell growth. In this study, we examined the inhibitory effects of a novel CK2 inhibitor, hematein, on tumor growth in a murine xenograft model. We found that in lung cancer cells, hematein inhibited cancer cell growth, Akt/PKB Ser129 phosphorylation, the Wnt/TCF pathway and increased apoptosis. In a murine xenograft model of lung cancer, hematein inhibited tumor growth without significant toxicity to the mice tested. Molecular docking showed that hematein binds to CK2α in durable binding sites. Collectively, our results suggest that hematein is an allosteric inhibitor of protein kinase CK2 and has antitumor activity to lung cancer.

Topics: Animals; Apoptosis; Blotting, Western; Casein Kinase II; Enzyme Inhibitors; Female; Hematoxylin; Humans; Immunoenzyme Techniques; Lung Neoplasms; Mice; Mice, Inbred BALB C; Phosphorylation; Proto-Oncogene Proteins c-akt; T Cell Transcription Factor 1; Tumor Cells, Cultured; Wnt Proteins; Xenograft Model Antitumor Assays

Casein kinase 2 (CK2) is known to be involved in various cellular processes such as cell cycle, apoptosis and proliferation. It has been reported that the inhibition of CK2 induced by recently developed small molecule CX4945 shows anti-cancer effects including anti-proliferation and anti-angiogenesis in several different cancers including prostate cancer. Here we report that migration and invasion of A549 human lung cancer cells are suppressed by the inhibition of CK2 induced by CX4945. We found that CX4945 sequentially attenuates the proteins in PI3K/Akt and MAPK pathways, two signaling pathways related with cell migration. This sequential control of signal pathways inhibits the expression of membrane type 1-matrix metalloproteinase and this leads to the selective attenuation of one of the gelatinases, MMP-2, which can degrade components of extracellular matrix, and metastasis of A549 human lung cancer cell.

Topics: Antineoplastic Agents; Casein Kinase II; Cell Line, Tumor; Cell Movement; Cell Survival; Gelatinases; Humans; Lung Neoplasms; Matrix Metalloproteinase 1; Matrix Metalloproteinase 2; Mitogen-Activated Protein Kinase Kinases; Naphthyridines; Phenazines; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Signal Transduction

The epithelial-to-mesenchymal transition (EMT) is a major phenotype of cancer metastasis and invasion. As a druggable cancer target, the inhibition of protein kinase CK2 (formally named to casein kinase 2) has been suggested as a promising therapeutic strategy to treat EMT-controlled cancer metastasis. This study aimed to evaluate the effect of the CK2 inhibitor CX-4945 on the processes of cancer migration and invasion during the EMT in A549 human lung adenocarcinoma cells.. The effect of CX-4945 on TGF-β1-induced EMT was evaluated in A549 cells treated with TGF-β1 (5 ng/ml) and CX-4945. The effect of CX-4945 on TGF-β1-induced cadherin switch and activation of key signaling molecules involved in Smad, non-Smad, Wnt and focal adhesion signaling pathways were investigated by Western blot analysis, immunocytochemistry and reporter assay. Additionally, the effect of CX-4945 on TGF-β1-induced migration and invasion was investigated by wound healing assay, Boyden chamber assay, gelatin zymography, and the quantitative real-time PCR.. CX-4945 inhibits the TGF-β1-induced cadherin switch and the activation of key signaling molecules involved in Smad (Smad2/3, Twist and Snail), non-Smad (Akt and Erk), Wnt (β-catenin) and focal adhesion signaling pathways (FAK, Src and paxillin) that cooperatively regulate the overall process of EMT. As a result, CX-4945 inhibits the migration and invasion of A549 cells accompanied with the downregulation of MMP-2 and 9.. Clinical evaluation of CX-4945 in humans as a single agent in solid tumors and multiple myeloma has established its promising pharmacokinetic, pharmacodynamic, and safety profiles. Beyond regression of tumor mass, CX-4945 may be advanced as a new therapy for cancer metastasis and EMT-related disorders.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Cadherins; Casein Kinase II; Cell Line, Tumor; Cell Movement; Epithelial-Mesenchymal Transition; Focal Adhesion Kinase 1; Humans; Lung Neoplasms; Naphthyridines; Neoplasm Invasiveness; Paxillin; Phenazines; Protein Kinase Inhibitors; Signal Transduction; Smad Proteins; Transforming Growth Factor beta1; Wnt Proteins

Radioresistance is considered as a main factor restricting efficacy of radiotherapy. However, the exact molecular mechanism of radioresistance has not been explained yet. In this study, to elucidate radioresistance mechanism in lung cancer, we compared radiation responses in two types of non-small cell lung cancer (NSCLC) cells with different radiosensitivity and identified key molecules conferring radioresistance. In radioresistant NSCLC cells, ionizing radiation (IR) led to casein kinase 2α (CK2α)- and PKC-mediated phosphorylation of rpS3 and TRAF2, respectively, which induced dissociation of rpS3-TRAF2 complex and NF-κB activation, resulting in significant up-regulation of prosurvival genes (cIAP1, cIAP2, and survivin). Also, dissociated phospho-rpS3 translocated into nucleus and bound with NF-κB complex (p65 and p50), contributing to p65 DNA binding property and specificity. However, in radiosensitive NSCLC cells, IR-mediated rpS3 phosphorylation was not detected due to the absence of CK2α overexpression. Consequently, IR-induced rpS3-TRAF2 complex dissociation, NF-κB activation, and prosurvival gene expression were not presented. Taken together, our findings revealed a novel radioresistance mechanism through functional orchestration of rpS3, TRAF2, and NF-κB in NSCLC cells. Moreover, we provided the first evidence for the function of rpS3 as a new TRAF2-binding protein and demonstrated that phosphorylation of both rpS3 and TRAF2 is a key control point of radioresistance in NSCLC cells. These results suggest that regulation of rpS3 and TRAF2 in combination with radiotherapy could have high pharmacological therapeutic potency for radioresistance of NSCLC.

Topics: Apoptosis; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cell Line, Tumor; Cell Nucleus; Humans; Lung Neoplasms; Models, Biological; NF-kappa B; Phosphorylation; Protein Binding; Protein Transport; Radiation Tolerance; Radiation, Ionizing; Ribosomal Proteins; TNF Receptor-Associated Factor 2

Cell surface nucleolin (NCL) plays fundamental roles in tumor angiogenesis. However, the mechanism underlying its surface translocation remains obscure. The present study discovered that heat shock cognate 70 (Hsc70) is essential in both the surface translocation and the angiogenic function of NCL.. We identified that Hsc70 interacted with NCL in endothelial cells via the peptide-binding domain of Hsc70 and the RNA-binding domain of NCL. Functional knockdown of Hsc70 remarkably inhibited the expression of surface NCL, which was rescued by wild-type Hsc70 rather than its truncations. Phosphorylation of NCL by either protein kinase C-ξ or casein kinase 2 mediated its interaction with Hsc70 and the surface expression. Hsc70 regulated NCL translocation via stabilizing NCL and enhancing its interaction with nonmuscle myosin heavy chain 9. Moreover, Hsc70 was associated with NCL-induced endothelial cell migration and tubule formation in vitro and angiogenesis in both matrigel plugs and xenograft tumors. Tissue array analysis revealed that the expression levels of NCL and Hsc70 were intimately correlated in human lung adenocarcinomas.. Our study demonstrates that Hsc70 is a prerequisite for the surface translocation and angiogenic function of NCL, which suggests strategies to target both Hsc70 and NCL for more effective antiangiogenic therapies.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Animals; Benzhydryl Compounds; Binding Sites; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cell Line, Tumor; Cell Movement; HSC70 Heat-Shock Proteins; Human Umbilical Vein Endothelial Cells; Humans; Lung Neoplasms; Mice; Mice, Nude; Myosin Heavy Chains; Neovascularization, Pathologic; Neovascularization, Physiologic; Nucleolin; Phosphoproteins; Phosphorylation; Protein Interaction Domains and Motifs; Protein Interaction Mapping; Protein Kinase C-epsilon; Protein Stability; Protein Transport; Pyrrolidinones; RNA Interference; RNA-Binding Proteins; Tissue Array Analysis; Transfection; Xenograft Model Antitumor Assays

Protein kinase CK2 is frequently elevated in a variety of human cancers. The Hedgehog (Hh) signaling pathway has been implicated in stem cell maintenance, and its aberrant activation has been indicated in several types of cancer, including lung cancer. In this study, we show that CK2 is positively involved in Hh/Gli signaling in lung cancer cell lines A549 and H1299. First, we found a correlation between CK2α and Gli1 mRNA levels in 100 primary lung cancer tissues. Down-regulation of Gli1 expression and transcriptional activity were demonstrated after the silencing of CK2α in lung cancer cells. In addition, CK2α siRNA down-regulated the expression of Hh target genes. Furthermore, two small-molecule CK2α inhibitors led to a dose-dependent inhibition of Gli1 expression and transcriptional activity in lung cancer cells. Reversely, forced over-expression of CK2α resulted in an increase both in Gli1 expression and transcriptional activity in A549 cells. Finally, the inhibition of Hh/Gli by CK2α siRNA led to a reduction of a cancer stem cell-like side population that shows higher ABCG2 expression level. Thus, we report that the inhibition of CK2α down-regulates Hh/Gli signaling and subsequently reduces stem-like side population in human lung cancer cells.

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 2; ATP-Binding Cassette Transporters; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cell Count; Cell Line, Tumor; Down-Regulation; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Gene Silencing; Humans; Lung Neoplasms; Neoplasm Proteins; Neoplastic Stem Cells; Protein Kinase Inhibitors; Proteolysis; Side-Population Cells; Signal Transduction; Small Molecule Libraries; Transcription Factors; Transcription, Genetic; Transcriptional Activation; Up-Regulation; Zinc Finger Protein GLI1

CK2 is a serine threonine kinase that participates in a variety of cellular processes with more than 300 defined substrates. This critical enzyme is known to be upregulated in cancers, but the role of this upregulation in carcinogenesis is not yet fully understood but c-myc, one of the defined CK2 substrates, is a well-known proto- oncogene that is normally essential in developmental process but is also involved in tumor development. We evaluated the optimal enzyme and substrate concentrations for CK2 activity in both neoplastic and non-neoplastic human lung tissues using the c-myc 424-434 peptide (EQKLISEEDL) as a substrate. The activities measured for the neoplastic tissue were 600-750 U/mg protein while those for the control tissue was in the range of 650-800 U/ mg. Km value for c-myc peptide was determined as 0.33 μM in non-neoplastic tissue and 0.18 μM in neoplastic tissue. In this study, we did not observe an increased activity in the neoplastic tissue when compared with the non-neoplastic lung tissue, but we recorded two times higher affinity for c-myc 424-434 in cancer tissue. Considering the metabolic position of c-myc 424-434, our results suggest that phosphorylation by CK2 may be important in dimerization and thus it might affect the regulation of c-myc in cancer tissues.

Topics: Amino Acid Sequence; Casein Kinase II; Cell Transformation, Neoplastic; Gene Expression Regulation, Neoplastic; Humans; Lung; Lung Neoplasms; Molecular Sequence Data; Peptide Fragments; Prognosis; Proto-Oncogene Mas; Proto-Oncogene Proteins c-myc

CK2 interacts and phosphorylates >300 proteins, including Stat3, and is linked to a number of human cancers. Constitutively activated Stat3 has been reported in 50% of human lung cancers. Inhibition of CK2 activity can induce apoptosis and suppression of Stat3 activation in cancer cells. This study examined the effects of CK2 inhibitors on growth inhibition of lung cancer cells and the therapeutic potential on lung cancer. The CK2 inhibitor and radiation both suppressed cancer cell growth in a dose-dependent manner. Besides, the cytotoxic effect of irradiation could be augmented by CK2 inhibitors (p<0.05, two-way analysis of variance and Tukey's Honestly Significant Difference). Moreover, the growth inhibition of CK2 inhibitor and irradiation was both associated with suppression of Stat3 activation. Taken together, inhibition of CK2 activity appears to be a promising treatment strategy for non-small cell lung cancer and CK2 inhibition results in reduced Stat3 activation. Our data warrant further effort to develop CK2-targeted radiosensitizer for lung cancer treatment.

Topics: Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cell Line, Tumor; Cell Survival; Dose-Response Relationship, Drug; Dose-Response Relationship, Radiation; Enzyme Inhibitors; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Radiation Tolerance; Radiation-Sensitizing Agents; STAT3 Transcription Factor

Protein kinase CK2 is frequently up-regulated in human cancers, although the mechanism of CK2 activation in cancer remains unknown. In this study, we investigated the role of the CK2alpha intronless gene (CSNK2A1P, a presumed CK2alpha pseudogene) in the pathogenesis of human cancers. We found evidence of amplification and over-expression of the CSNK2A1P gene in non-small cell lung cancer and leukemia cell lines and 25% of the lung cancer tissues studied. The mRNA expression levels correlated with the copy numbers of the CSNK2A1P gene. We also identified a novel polymorphic variant (398T/C, I133T) of the CSNK2A1P gene and showed that the 398T allele is selectively amplified over the 398C allele in 101 non-small cell lung cancer tissue samples compared to those in 48 normal controls (p = 0.013<0.05). We show for the first time CSNK2A1P protein expression in transfected human embryonic kidney 293T and mouse embryonic fibroblast NIH-3T3 cell lines. Both alleles are transforming in these cell lines, and the 398T allele appears to be more transforming than the 398C allele. Moreover, the 398T allele degrades PML tumor suppressor protein more efficiently than the 398C allele and shows a relatively stronger binding to PML. Knockdown of the CSNK2A1P gene expression with specific siRNA increased the PML protein level in lung cancer cells. We report, for the first time, that the CSNK2A1P gene is a functional proto-oncogene in human cancers and its functional polymorphism appears to degrade PML differentially in cancer cells. These results are consistent with an important role for the 398T allele of the CSNK2A1P in human lung cancer susceptibility.

Topics: Animals; Blotting, Western; Casein Kinase II; Cell Line; Cell Line, Tumor; Gene Expression Regulation, Neoplastic; Humans; Immunoprecipitation; In Situ Hybridization, Fluorescence; In Vitro Techniques; Lung Neoplasms; Mice; NIH 3T3 Cells; Nuclear Proteins; Polymorphism, Genetic; Promyelocytic Leukemia Protein; Protein Binding; Proto-Oncogene Mas; Reverse Transcriptase Polymerase Chain Reaction; RNA, Small Interfering; Sequence Analysis, DNA; Transcription Factors; Tumor Suppressor Proteins

To analyze the prognostic significance of the genes casein kinase 2 alpha subunit (CSNK2A1), anti-apoptosis clone-11 (AAC-11), and tumor metastasis suppressor NME1 in completely resected non-small cell lung cancer (NSCLC) patients.. Total RNA was extracted from 145 cases of completely resected, formalin-fixed, paraffin-embedded NSCLC tissues. mRNA expression levels of CSNK2A1, AAC-11, and NME1 were detected by real-time reverse-transcriptase polymerase chain reaction. Univariate and multivariate survival analyses were used to identify factors related to prognosis.. A correlation between CSNK2A1 and AAC-11 mRNA expression levels (rs=0.366, p=0.000) was found. Univariate analysis showed that high expression of CSNK2A1 and AAC-11 was predictive of poor prognosis in NSCLC patients (p=0.029 and 0.044, respectively), especially when expression levels of both genes were concomitantly high (p=0.007). Multivariate Cox regression analysis showed that high expression of CSNK2A1, or concomitantly high expression of CSNK2A1 and AAC-11, are independent prognostic factors of poor survival in NSCLC patients. However, NME1 mRNA expression level did not significantly influence survival in NSCLC patients.. This retrospective study indicates that CSNK2A1 and AAC-11, especially in combination, are useful prognosis markers in NSCLC patients after complete resection, independent of lymph node metastasis status.

Topics: Adult; Aged; Apoptosis Regulatory Proteins; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Female; Gene Expression Regulation, Neoplastic; Humans; Kaplan-Meier Estimate; Lung Neoplasms; Male; Middle Aged; NM23 Nucleoside Diphosphate Kinases; Nuclear Proteins; Prognosis; RNA, Messenger

Casein kinase 2 (CK2) is dysregulated in various human cancers and is a promising target for cancer therapy. To date, there is no small molecular CK2 inhibitor in clinical trial yet. With the aim to identify novel CK2 inhibitors, we screened a natural product library.. We adopted cell-based proliferation and CK2 kinase assays to screen CK2 inhibitors from a natural compound library. Dose-dependent response of CK2 inhibitors in vitro was determined by a radioisotope kinase assay. Western blot analysis was used to evaluate down stream Akt phosphorylation and apoptosis. Apoptosis was also evaluated by annexin-V/propidium iodide (PI) labeling method using flow cytometry. Inhibition effects of CK2 inhibitors on the growth of cancer and normal cells were evaluated by cell proliferation and viability assays.. Hematein was identified as a novel CK2 inhibitor that is highly selective among a panel of kinases. It appears to be an ATP non-competitive and partially reversible CK2 inhibitor with an IC50 value of 0.55 muM. In addition, hematein inhibited cancer cell growth partially through down-regulation of Akt phosphorylation and induced apoptosis in these cells. Furthermore, hematein exerted stronger inhibition effects on the growth of cancer cells than in normal cells.. In this study, we showed that hematein is a novel selective and cell permeable small molecule CK2 inhibitor. Hematein showed stronger growth inhibition effects to cancer cells when compared to normal cells. This compound may represent a promising class of CK2 inhibitors.

Topics: Adenosine Triphosphate; Apoptosis; Casein Kinase II; Cell Growth Processes; Cell Line, Tumor; Dose-Response Relationship, Drug; HCT116 Cells; HeLa Cells; Hematoxylin; Humans; Lung Neoplasms; Neoplasms; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Substrate Specificity

The PML tumor suppressor controls growth suppression, induction of apoptosis, and cellular senescence. PML loss occurs frequently in hematopoietic and solid tumors. PML loss often correlates with tumor progression. Casein kinase 2 (CK2) is a stress-activated serine/threonine protein kinase that is oncogenic and frequently overexpressed in human tumor of multiple histological origins. In addition, CK2 overexpression due to gene amplification has been reported to be an adverse prognostic factor in non-small cell lung cancer. At the 5th International Conference on Protein Kinase CK2 in Padova, Italy, we reviewed our recent findings that PML undergoes ubiquitin/proteasome-mediated degradation in immortalized and tumor derived cell lines. PML degradation depends on direct CK2 phosphorylation of PML Ser517. PML mutants that are resistant to CK2 phosphorylation display increased tumor suppressive functions in assays measuring apoptosis, replicative senescence, and in xenograft models. More significantly, CK2 pharmacological inhibition enhances PML tumor suppressive property. These data identify a key post-translational mechanism that controls PML protein levels in cancer cells and suggest that CK2 inhibitors may be beneficial anti-cancer drugs.

Topics: Amino Acid Sequence; Animals; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cell Line, Tumor; Enzyme Activation; Humans; Lung Neoplasms; Mice; Mice, Nude; Molecular Sequence Data; Mutation; Nuclear Proteins; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Promyelocytic Leukemia Protein; Proteasome Endopeptidase Complex; Protein Kinase Inhibitors; Protein Processing, Post-Translational; Thermodynamics; Transcription Factors; Tumor Suppressor Proteins; Ubiquitin; Ubiquitination

The antitumor efficacy of the CK2 inhibitors so far described has not been extensively evaluated in cancer animal models. We have previously demonstrated that a proapoptotic cyclic peptide termed P15 delivered into the cells by the Tat Cell Penetrating Peptide was able to abrogate the CK2-mediated phosphorylation and induce tumor regression when injected directly into solid tumors in mice. Here we explored the antitumor effect by systemic administration of P15-Tat in a consecutive 5-day schedule through either intraperitoneal or intravenous route. Importantly, significant delay of tumor growth was observed at 2 mg/kg (p < 0.05), 10 mg/kg (p < 0.01) or 40 mg/kg (p < 0.001) after P15-Tat administration both in syngeneic murine tumors and human tumors xenografted in nude mice. In line with this, the systemic administration of P15-Tat induced apoptosis in the tumor as evidenced by in situ DNA fragmentation. Furthermore, we evidenced that 99mTc-labeled P15-Tat peptide was certainly accumulated on the tumors after administration by both routes. This report becomes the first describing the antitumor effect induced by systemic administration of a peptide that targets the acidic phosphorylation domain for CK2 substrates. Also, our data reinforces the perspectives of P15-Tat for the cancer targeted therapy.

Topics: Animals; Apoptosis; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cell Line, Tumor; Cyclin-Dependent Kinase Inhibitor p15; Female; Gene Products, tat; Humans; Lung Neoplasms; Mice; Mice, Inbred C57BL; Mice, Nude; Peptides, Cyclic; Phosphorylation; Protein Kinase Inhibitors; Tissue Distribution; Transplantation, Heterologous

Elevated level of oxygen (hyperoxia) is widely used in critical care units and in respiratory insufficiencies. In addition, hyperoxia has been implicated in many diseases such as bronchopulmonary dysplasia or acute respiratory distress syndrome. Although hyperoxia is known to cause DNA base modifications and strand breaks, the DNA damage response has not been adequately investigated. We have investigated the effect of hyperoxia on DNA damage signaling and show that hyperoxia is a unique stress that activates the ataxia telangiectasia mutant (ATM)- and Rad3-related protein kinase (ATR)-dependent p53 phosphorylations (Ser6, -15, -37, and -392), phosphorylation of histone H2AX (Ser139), and phosphorylation of checkpoint kinase 1 (Chk1). In addition, we show that phosphorylation of p53 (Ser6) and histone H2AX (Ser139) depend on both ATM and ATR. We demonstrate that ATR activation precedes ATM activation in hyperoxia. Finally, we show that ATR is required for ATM activation in hyperoxia. Taken together, we report that ATR is the major DNA damage signal transducer in hyperoxia that activates ATM.

Topics: Adaptor Proteins, Signal Transducing; Adenocarcinoma; Apoptosis; Ataxia Telangiectasia Mutated Proteins; Casein Kinase II; Cell Cycle Proteins; Cell Line, Tumor; Checkpoint Kinase 1; DNA Repair; DNA-Binding Proteins; Histones; Humans; Hyperoxia; Lung Neoplasms; Phosphorylation; Protein Kinases; Protein Serine-Threonine Kinases; RNA Interference; Serine; Signal Transduction; Tumor Suppressor Protein p53; Tumor Suppressor Proteins

The tumor suppressor p53 is an important cellular protein, which controls cell cycle progression. Phosphorylation is one of the mechanisms by which p53 is regulated. Here we report the interaction of p53 with another key regulator, cdk9, which together with cyclin T1 forms the positive transcription elongation complex, p-TEFb. This complex cooperates with the HIV-1 Tat protein to cause the phosphorylation of the carboxyl terminal domain (CTD) of RNA polymerase II and this facilitates the elongation of HIV-1 transcription. We demonstrate that cdk9 phosphorylates p53 on serine 392 through their direct physical interaction. Results from protein-protein interaction assays revealed that cdk9 interacts with the C-terminal domain (aa 361-393) of p53, while p53 interacts with the N-terminal domain of cdk9. Transfection and protein binding assays (EMSA and ChIP) demonstrated the ability of p53 to bind and activate the cdk9 promoter. Interestingly, cdk9 phosphorylates serine 392 of p53, which could be also phosphorylated by casein kinase II. Kinase assays demonstrated that cdk9 phosphorylates p53 independently of CKII. These studies demonstrate the existence of a feedback-loop between p53 and cdk9, pinpointing a novel mechanism by which p53 regulates the basal transcriptional machinery.

Topics: Brain Neoplasms; Casein Kinase II; Cell Line, Tumor; Cyclin-Dependent Kinase 9; Glioblastoma; HIV-1; Humans; Kinetics; Lung Neoplasms; Phosphorylation; Recombinant Proteins; Serine; Transcription, Genetic; Tumor Suppressor Protein p53

The PML protein induces senescence, and, upon oncogenic stress, its absence promotes cellular transformation. In this issue of Cell, Scaglioni et al. (2006) show that phosphorylation of PML by CK2, a kinase frequently activated in human cancers, promotes PML degradation. Therefore, pharmacological inhibition of CK2-induced PML loss could be used to offset tumor establishment.

Topics: Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cell Transformation, Neoplastic; Enzyme Activation; Gene Expression Regulation, Neoplastic; Genes, Tumor Suppressor; Humans; Lung Neoplasms; Neoplasm Proteins; Nuclear Proteins; Phosphorylation; Promyelocytic Leukemia Protein; Proteasome Endopeptidase Complex; Transcription Factors; Tumor Suppressor Proteins

The PML tumor suppressor controls key pathways for growth suppression, induction of apoptosis, and cellular senescence. PML loss occurs frequently in human tumors through unknown posttranslational mechanisms. Casein kinase 2 (CK2) is oncogenic and frequently upregulated in human tumors. Here we show that CK2 regulates PML protein levels by promoting its ubiquitin-mediated degradation dependent on direct phosphorylation at Ser517. Consequently, PML mutants that are resistant to CK2 phosphorylation display increased tumor-suppressive functions. In a faithful mouse model of lung cancer, we demonstrate that Pml inactivation leads to increased tumorigenesis. Furthermore, CK2 pharmacological inhibition enhances the PML tumor-suppressive property in vivo. Importantly, we found an inverse correlation between CK2 kinase activity and PML protein levels in human lung cancer-derived cell lines and primary specimens. These data identify a key posttranslational mechanism that controls PML protein levels and provide therapeutic means toward PML restoration through CK2 inhibition.

Topics: Amino Acid Sequence; Amino Acid Substitution; Animals; Apoptosis; Carcinoma, Non-Small-Cell Lung; Casein Kinase II; Cell Line; Cell Line, Transformed; Cell Line, Tumor; Enzyme Activation; Enzyme Inhibitors; Genes, Tumor Suppressor; Green Fluorescent Proteins; Hemagglutinins; Humans; Leupeptins; Lung Neoplasms; Mice; Mice, Transgenic; Molecular Sequence Data; Neoplasm Proteins; NIH 3T3 Cells; Nuclear Proteins; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Promyelocytic Leukemia Protein; Proteasome Endopeptidase Complex; Protein Structure, Tertiary; Protein Subunits; RNA, Small Interfering; Sequence Deletion; Serine; Sorbitol; Transcription Factors; Transcriptional Activation; Triazoles; Tumor Suppressor Proteins; Ubiquitin

Gene expression profiling has been shown to be a valuable tool for prognostication and identification of cancer-associated genes in human malignancies. We aimed to identify potential prognostic marker(s) in non-small cell lung cancers using global gene expression profiles.. Twenty-one previously untreated patients with non-small cell lung cancer were analyzed using the Affymetrix GeneChip high-density oligonucleotide array and comparative genomic hybridization. Identified candidate genes were validated in an independent cohort of 45 patients using quantitative real-time reverse transcription-PCR and Western blot analyses. Follow-up data for these patients was collected and used to assess outcome correlations.. Hierarchical clustering analysis yielded three distinct subgroups based on gene expression profiling. Cluster I consisted of 4 patients with adenocarcinoma and 1 with squamous cell carcinoma (squamous cell carcinoma); clusters II and III consisted of 6 and 10 patients with squamous cell carcinoma, respectively. Outcome analysis was performed on the cluster groups containing solely squamous cell carcinoma, revealing significant differences in disease-specific survival rates. Moreover, patients having a combination of advanced Tumor-Node-Metastasis stage and assigned to the poor prognosis cluster group (cluster II) had significantly poorer outcomes. Comparative genomic hybridization analysis showed recurrent chromosomal losses at 1p, 3p, 17, 19, and 22 and gains/amplifications at 3q, 5p, and 8q, which did not vary significantly between the cluster groups. We internally and externally validated a subset of 11 cluster II (poor prognosis)-specific genes having corresponding chromosomal aberrations identified by comparative genomic hybridization as prognostic markers in an independent cohort of patients with lung squamous cell carcinoma identifying CSNK2A1 and C1-Inh as independent predictors of outcome.. CSNK2A1 and C1-Inh are independent predictors of survival in lung squamous cell carcinoma patients and may be useful as prognostic markers.

Topics: Aged; Biomarkers, Tumor; Blotting, Western; Carcinoma, Squamous Cell; Casein Kinase II; Chromosome Aberrations; Cluster Analysis; Cohort Studies; Complement C1 Inactivator Proteins; Complement C1 Inhibitor Protein; Cysteine Proteinase Inhibitors; Female; Follow-Up Studies; Gene Expression Profiling; Humans; Lung Neoplasms; Male; Nucleic Acid Hybridization; Oligonucleotide Array Sequence Analysis; Predictive Value of Tests; Prognosis; Protein Subunits; Survival Rate