CKAP2 (cytoskeleton-associated protein2) is a new prognostic marker in HER2-negative luminal type breast cancer.

Background: Recently, we reported cytoskeleton-associated protein2 (CKAP2) as a possible new prognostic breast cancer marker. However, it has not yet been applied in clinic. Therefore, clinical significance of CKAP2 was evaluated in comparison with that of Ki-67 in a cohort of breast cancer patients, and the expression difference was analyzed in cell cycle-arrested cancer and fibroblast cells.

CKAP2 phosphorylation by CDK1/cyclinB1 is crucial for maintaining centrosome integrity.

Previously, we have reported that CKAP2 is involved in the maintenance of centrosome integrity, thus allowing for proper mitosis in primary hepatocytes. To understand this biological process, we identified the mitosis-specific phosphorylation sites in mouse CKAP2 and investigated CKAP's possible role in cell cycle progression. Because we observed mouse CKAP2 depletion in amplified centrosomes and aberrant chromosomal segregation, which was rescued by ectopic expression of wild-type CKAP2, we focused on the centrosome duplication process among the various aspects of the cell cycle.

CKAP2 is necessary to ensure the faithful spindle bipolarity in a dividing diploid hepatocyte.

Spindle bipolarity is crucial for segregating chromosome during somatic cell division. Previous studies have suggested that cytoskeleton associated protein 2 (CKAP2) is involved in spindle assembly and chromosome segregation. In this study, we show that CKAP2-depleted primary hepatocytes exhibit over-duplicated centrosomes with disjoined chromosomes from metaphase plate.

Clinical implications of proliferation activity in T1 or T2 male gastric cancer patients.

Proliferation activity has already been established as a prognostic marker or as a marker for anticancer drug sensitivity. In gastric cancer, however, the prognostic significance of proliferation activity is still being debated. Several studies evaluating proliferation activity using Ki-67 have shown controversial results in terms of the relationship between proliferation activity and overall survival (OS) or drug sensitivity in gastric cancer patients.

Identification of novel phosphatidic acid-binding proteins in the rat brain.

Phosphatidic acid (PA) is an abundant negatively-charged phospholipid and has long been considered to be an important signaling molecule in diverse cellular events. Thus, the identification of proteins that specifically interact with PA is of considerable interest to understand the regulatory roles of PA. Herein, lipid-affinity purification and mass spectrometric analysis reveals 43 proteins, 19 known and 24 novel, as PA-binding proteins.

Chromatin CKAP2, a new proliferation marker, as independent prognostic indicator in breast cancer.

Background: The level of proliferation activity is a strong prognostic or predictive indicator in breast cancer, but its optimal measurement is still in debate, necessitating new proliferation markers. In the present study, the prognostic significance of the CKAP2-positive cell count (CPCC), a new proliferation marker, was evaluated, and the results were compared with those for the mitotic activity index (MAI).

Methods: This study included 375 early-stage breast cancer samples collected from two institutions between 2000 and 2006.

p90 ribosomal S6 kinase 1 (RSK1) isoenzyme specifically regulates cytokinesis progression.

The p90 ribosomal S6 kinase family (RSK1-4) of Ser/Thr kinases is a downstream component of the Ras-MAPK cascade responsible for regulating various cellular processes. Here, we examined the potential involvement of RSKs in regulating mitosis by transfecting HeLa cells with siRNAs targeting RSK1 and -2, which are the major isoforms. Depletion of RSK1 but not RSK2 triggered a significant accumulation of binucleated cells compared to control cells (0.

Cyclin A regulates a cell-cycle-dependent expression of CKAP2 through phosphorylation of Sp1.

CKAP2 plays crucial roles in proper chromosome segregation and maintaining genomic stability. CKAP2 protein showed cell-cycle-dependent expression, which reached a maximum level at the G2/M phase and disappeared at the onset of G1 phase. To elucidate the mechanisms underlying cell cycle-dependent expression of CKAP2, we cloned and analyzed the human CKAP2 promoter.

Condensed chromatin staining of CKAP2 as surrogate marker for mitotic figures.

Purpose: Proliferation activity has long been known to be one of the strongest prognostic factors in many different cancers. Nevertheless, microscopic evaluation of mitotic figures remains time-consuming and, furthermore, is relatively subjective. As the expression of cytoskeleton-associated protein 2 (CKAP2) is closely related to the mitotic phase, CKAP2 was evaluated as a surrogate mitotic figure (MF) marker.

I-kappaBalpha depletion by transglutaminase 2 and mu-calpain occurs in parallel with the ubiquitin-proteasome pathway.

Transglutaminase 2 (TGase2) is a calcium-dependent, cross-linking enzyme that catalyzes iso-peptide bond formation between peptide-bound lysine and glutamine residues. TGase 2 can activate NF-kappaB through the polymerization-mediated depletion of I-kappaBalpha without IKK activation. This NF-kappaB activation mechanism is associated with drug resistance in cancer cells.

Specific primary sequence requirements for Aurora B kinase-mediated phosphorylation and subcellular localization of TMAP during mitosis.

During mitosis, regulation of protein structures and functions by phosphorylation plays critical roles in orchestrating a series of complex events essential for the cell division process. Tumor-associated microtubule-associated protein (TMAP), also known as cytoskeleton-associated protein 2 (CKAP2), is a novel player in spindle assembly and chromosome segregation. We have previously reported that TMAP is phosphorylated at multiple residues specifically during mitosis.

Glutamate receptor-mediated phosphorylation of ezrin/radixin/moesin proteins is implicated in filopodial protrusion of primary cultured hippocampal neuronal cells.

Previously, we reported the phosphorylation of moesin induced by electroconvulsive shock in rat brain and by glutamate in immortalized rat hippocampal cells. However, the function of phosphorylated moesin in differentiated neurons is not well understood. In this study, we observed that glutamate induces phosphorylation of ezrin/radixin/moesin proteins (ERM) in cultured hippocampal cells and that phosphorylated ERM localizes at the newly formed filopodia of neurites.

NGF-induced moesin phosphorylation is mediated by the PI3K, Rac1 and Akt and required for neurite formation in PC12 cells.

Moesin is a member of ERM family proteins which act as the cross-linkers between plasma membrane and actin-cytoskeleton and is activated by phosphorylation at Thr-558. In neurons, suppression of radixin and moesin alters the growth cone morphology. However, the significance of phosphorylation of ERM proteins in neuronal cells has not been fully investigated.

Chloride channel conductance is required for NGF-induced neurite outgrowth in PC12 cells.

We have previously shown that in PC12 cells: (1) high extracellular KCl induces moesin phosphorylation, an event which was dependent on chloride channel activation, and (2) NGF induces moesin phosphorylation which is required for neurite outgrowth. These results suggest that NGF-induced intracellular signaling and neurite outgrowth is also mediated by activation of anion channels. Using a patch-clamp technique, we found that NGF treatment increased anionic conductance in PC12 cells, an effect which was completely blocked by NPPB, a chloride channel inhibitor.

Characterization of mitosis-specific phosphorylation of tumor-associated microtubule-associated protein.

Tumor-associated microtubule-associated protein (TMAP), also known as cytoskeleton associated protein 2 (CKAP2), has been recently shown to be involved in the assembly and maintenance of mitotic spindle and also plays an essential role in maintaining the fidelity of chromosome segregation during mitosis. We have previously reported that TMAP is phosphorylated at multiple residues specifically during mitosis, and characterized the mechanism and functional importance of phosphorylation at one of the mitosis-specific phosphorylation residues (i.e.

Cdk1-cyclin B1-mediated phosphorylation of tumor-associated microtubule-associated protein/cytoskeleton-associated protein 2 in mitosis.

During mitosis, establishment of structurally and functionally sound bipolar spindles is necessary for maintaining the fidelity of chromosome segregation. Tumor-associated microtubule-associated protein (TMAP), also known as cytoskeleton-associated protein 2 (CKAP2), is a mitotic spindle-associated protein whose level is frequently up-regulated in various malignancies. Previous reports have suggested that TMAP is a potential regulator of mitotic spindle assembly and dynamics and that it is required for chromosome segregation to occur properly.

Protective effects of gabapentin on allodynia and alpha 2 delta 1-subunit of voltage-dependent calcium channel in spinal nerve-ligated rats.

This study was designed to determine whether early gabapentin treatment has a protective analgesic effect on neuropathic pain and compared its effect to the late treatment in a rat neuropathic model, and as the potential mechanism of protective action, the alpha(2)delta(1)-subunit of the voltage-dependent calcium channel (alpha(2)delta(1)-subunit) was evaluated in both sides of the L5 dorsal root ganglia (DRG). Neuropathic pain was induced in male Sprague-Dawley rats by a surgical ligation of left L5 nerve. For the early treatment group, rats were injected with gabapentin (100 mg/kg) intraperitoneally 15 min prior to surgery and then every 24 hr during postoperative day (POD) 1-4.

TMAP/CKAP2 is essential for proper chromosome segregation.

Tumor-associated microtubule-associated protein (TMAP), also known as cytoskeleton associated protein 2 (CKAP2), is a novel mitotic spindle-associated protein which is frequently up-regulated in various malignances. However, its cellular functions remain unknown. Previous reports suggested that the cellular functions of TMAP/CKAP2 pertain to regulation of the dynamics and assembly of the mitotic spindle.

Transient phosphorylation of tumor associated microtubule associated protein (TMAP)/cytoskeleton associated protein 2 (CKAP2) at Thr-596 during early phases of mitosis.

Tumor associated microtubule associated protein (TMAP), also known as cytoskeleton associated protein 2 (CKAP2) is a mitotic spindle-associated protein whose expression is cell cycle-regulated and also frequently deregulated in cancer cells. Two monoclonal antibodies (mAbs) against TMAP/CKAP2 were produced: B-1-13 and D-12-3. Interestingly, the reactivity of mAb D-12-3 to TMAP/CKAP2 was markedly decreased specifically in mitotic cell lysate.

Proteomic analysis to identify biomarker proteins in pancreatic ductal adenocarcinoma.

Background: Pancreatic ductal adenocarcinoma (PDAC) is the fifth most common cause of death from cancer in Korea. PDAC is difficult to diagnose at an early stage and even more difficult to cure. Thus, there is an urgent need to identify molecular targets for early diagnosis and effective treatment.

Downregulation of regenerating islet-derived 3 alpha (REG3A) in primary human gastric adenocarcinomas.

Gastric carcinoma is considered to be one of the most prevalent cancers worldwide. We have performed differential-display polymerase chain reaction (DD-PCR) in order to compare the gene expression profile of gastric carcinoma and that of a normal stomach, in an attempt to identifiy differentially expressed genes associated with primary human gastric cancers. One of the down-regulated genes in gastric cancers was identified as regenerating islet-derived 3 alpha (REG3A), also known as hepatocarcinoma-intestine-pancreas/ pancreatitis-associated protein (HIP/PAP).

Molecular imaging of endogenous mRNA expression in a mouse tumor model by adenovirus harboring trans-splicing ribozyme.

We previously showed that a trans-splicing ribozyme reprograms tumor-related genes at the mRNA level, resulting in the expression of therapeutic genes and that this approach can be efficiently employed to target specific molecules. Here, we show that trans-splicing ribozyme technology can be applied in molecular imaging of specific RNA expression in living animals. We exemplify this concept successfully by imaging mouse cytoskeleton-associated protein 2 (mCKAP2) expression in intrahepatic tumor nodules using systemically delivered adenovirus harboring mCKAP2-specific trans-splicing ribozyme.

PIAS1 interacts with the KRAB zinc finger protein, ZNF133, via zinc finger motifs and regulates its transcriptional activity.

Zinc finger protein 133 (ZNF133) is composed of a Krüppel-associated box (KRAB) domain and 14 contiguous zinc finger motifs. ZNF133 is regarded as a transcriptional repressor because the KRAB domain has potent repressor activity and the zinc finger motifs usually act in binding to DNA. However, we found that the zinc finger motifs of ZNF133 also possessed transcriptional repressor activity.

Selective regression of cells expressing mouse cytoskeleton-associated protein 2 transcript by trans-splicing ribozyme.

Cytoskeleton-associated protein 2 (CKAP2) is known to be highly expressed in primary human cancers as well as most cancer cell lines. CKAP2 functions as microtubule stabilizer and probably as cell proliferation inducer, indicating that CKAP2 might be a potential anticancer target. In this study, we developed a specific ribozyme that can replace mouse CKAP2 (mCKAP2) RNA with new transcripts through trans-splicing reaction.

Functional importance of the anaphase-promoting complex-Cdh1-mediated degradation of TMAP/CKAP2 in regulation of spindle function and cytokinesis.

Cytoskeleton-associated protein 2 (CKAP2), also known as tumor-associated microtubule-associated protein (TMAP), is a novel microtubule-associated protein that is frequently upregulated in various malignances. However, its cellular functions remain unknown. A previous study has shown that its protein level begins to increase during G(1)/S and peaks at G(2)/M, after which it decreases abruptly.