Cell Division Cycle 25A Research Articles

SIRT6 inhibits colorectal cancer stem cell proliferation by targeting CDC25A

Silent information regulator 6 (SIRT6) is broadly considered as a tumor suppressor due to its function in the suppression of oncogene expression. However, the role of SIRT6 in colorectal cancer stem cells (CSCs) remains uncharacterized. In the present study, it was demonstrated that SIRT6 expression was reduced in colorectal CSCs. Overexpression of SIRT6 in colorectal CSCs did not induce cell apoptosis. However, SIRT6 significantly inhibited cell proliferation, colony formation and induced G0/G1 phase arrest in colorectal CSCs. In addition, SIRT6 repressed the expression of cell division cycle 25A (CDC25A), an oncogenic phosphatase. Chromatin immunoprecipitation experiments indicated that SIRT6 directly bound to the CDC25A promoter and decreased the acetylation level of histone H3 lysine 9. Altogether, these data indicated that SIRT6 inhibits colorectal cancer stem cell proliferation by targeting CDC25A.

CDC25A (Cell division cycle 25A)

CDC25A (Cell division cycle 25A)

Linc00152 promotes malignant progression of glioma stem cells by regulating miR-103a-3p/FEZF1/CDC25A pathway

BackgroundGlioma is one of the most frequent intracranial malignant tumors. LncRNAs have been identified as new modulators in the origination and progression of glioma.MethodsQuantitative real-time PCR were conducted to evaluate the expression of linc00152 and miRNA-103a-3p in glioma tissues and cells. Western blot were used to determine the expression of FEZF1 and CDC25A in glioma tissues and cells. Stable knockdown of linc00152 or over-expression of miR-103a-3p in glioma stem cells (GSCs) were established to explore the function of linc00152 and miR-103a-3p in GSCs. Further, luciferase reports were used to investigate the correlation between linc00152 and miR-103a-3p. Cell Counting Kit-8, transwell assays, and flow cytometry were used to investigate the function of linc00152 and miR-103a-3p in GSC malignant biological behaviors. ChIP assays were employed to ascertain the correlations between FEZF1 and CDC25A.ResultsLinc00152 was up-regulated in glioma tissues as well as in GSCs. Knockdown of linc00152 inhibited cell proliferation, migration and invasion, while promoted GSC apoptosis. Linc00152 regulated the malignant behavior of GSCs by binding to miR-103a-3p, which functions as a tumor suppressor. In addition, knockdown of linc00152 down-regulated forebrain embryonic zinc finger protein 1 (FEZF1), a direct target of miR-103a-3p which played an oncogenic role in GSCs. FEZF1 elevated promoter activities and up-regulated expression of the oncogenic gene cell division cycle 25A (CDC25A). CDC25A over-expression activated the PI3K/AKT pathways, which regulated the malignant behavior of GSCs.ConclusionsLinc00152/miR-103a-3p/FEZF1/CDC25A axis plays a novel role in regulating the malignant behavior of GSCs, which may be a new potential therapeutic strategy for glioma therapy.

Novel coumarin- and quinolinone-based polycycles as cell division cycle 25-A and -C phosphatases inhibitors induce proliferation arrest and apoptosis in cancer cells

Cell division cycle phosphatases CDC25 A, B and C are involved in modulating cell cycle processes and are found overexpressed in a large panel of cancer typology. Here, we describe the development of two novel quinone-polycycle series of CDC25A and C inhibitors on the one hand 1a-k, coumarin-based, and on the other 2a-g, quinolinone-based, which inhibit either enzymes up to a sub-micro molar level and at single-digit micro molar concentrations, respectively. When tested in six different cancer cell lines, compound 2c displayed the highest efficacy to arrest cell viability, showing in almost all cell lines sub-micro molar IC50 values, a profile even better than the reference compound NCS95397. To investigate the putative binding mode of the inhibitors and to develop quantitative structure-activity relationships, molecular docking and 3-D QSAR studies were also carried out. Four selected inhibitors, 1a, 1d, 2a and 2c have been also tested in A431 cancer cells; among them, compound 2c was the most potent one leading to cell proliferation arrest and decreased CDC25C protein levels together with its splicing variant. Compound 2c displayed increased phosphorylation levels of histone H3, induction of PARP and caspase 3 cleavage, highlighting its contribution to cell death through pro-apoptotic effects.

Therapeutic miR-21 Silencing Ameliorates Diabetic Kidney Disease in Mice

Diabetic nephropathy is the main cause of end-stage renal disease. MicroRNAs are powerful regulators of the genome, and global expression profiling revealed miR-21 to be among the most highly regulated microRNAs in kidneys of mice with diabetic nephropathy. In kidney biopsies of diabetic patients, miR-21 correlated with tubulointerstitial injury. In situ PCR analysis showed a specific enrichment of miR-21 in glomerular cells. We identified cell division cycle 25a (Cdc25a) and cyclin-dependent kinase 6 (Cdk6) as novel miR-21 targets in mesangial cells. miR-21-mediated repression of Cdc25a and Cdk6 resulted in impaired cell cycle progression and subsequent mesangial cell hypertrophy. miR-21 increased podocyte motility by regulating phosphatase and tensin homolog (Pten). miR-21 antagonism invitro and invivo in streptozotocin-induced diabetic mice decreased mesangial expansion, interstitial fibrosis, macrophage infiltration, podocyte loss, albuminuria, and fibrotic- and inflammatory gene expression. In conclusion, miR-21 antagonism rescued various functional and structural parameters in mice with diabetic nephropathy and, thus, might be a viable option in the treatment of patients with diabetic kidney disease.

Role and regulation of Cdc25A phosphatase in neuron death induced by NGF deprivation or β-amyloid.

Neuron death during development and in Alzheimer’s disease (AD) is associated with aberrant regulation/induction of cell cycle proteins. However, the proximal events in this process are unknown. Cell cycle initiation requires dephosphorylation of cyclin-dependent kinases by cell division cycle 25A (Cdc25A). Here, we show that Cdc25A is essential for neuronal death in response to NGF deprivation or β-amyloid (Aβ) treatment and describe the mechanisms by which it is regulated in these paradigms. Cdc25A mRNA, protein and Cdc25A phosphatase activity were induced by NGF deprivation and Aβ treatment. Enhanced Cdc25A expression was also observed in rat brains infused with Aβ and in Aβ-overexpressing AβPPswe-PS1dE9 mice. In cultured neurons Cdc25A inhibition by chemical inhibitors or shRNA prevented cell death and neurite degeneration caused by NGF deprivation or Aβ. Additionally, Cdc25A inhibition diminished distal signaling events including Cdk-dependent elevation of phospho-pRb and subsequent caspase-3 activation. Mechanism studies revealed that Cdc25A induction by NGF deprivation and Aβ is mediated by activation of Forkhead transcription factors that in turn suppress miR-21, a negative regulator of Cdc25A. Our studies thus identify Cdc25A as a required upstream element of the apoptotic cell cycle pathway that is required for neuron death in response to trophic factor deprivation and to Aβ exposure and therefore as a potential target to suppress pathologic neuron death.

Effects of valproic acid and pioglitazone on cell cycle progression and proliferation of T-cell acute lymphoblastic leukemia Jurkat cells.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignant tumor. Administration of chemical compounds influencing apoptosis and T cell development has been discussed as promising novel therapeutic strategies. Valproic acid (VPA) as a recently emerged anti-neoplastic histone deacetylase (HDAC) inhibitor and pioglitazone (PGZ) as a high-affinity peroxisome proliferator-activated receptor-gamma (PPARγ) agonist have been shown to induce apoptosis and cell cycle arrest in different studies. Here, we aimed to investigate the underlying molecular mechanisms involved in anti-proliferative effects of these compounds on human Jurkat cells. Treated cells were evaluated for cell cycle progression and apoptosis using flowcytometry and MTT viability assay. Real-time RT-PCR was carried out to measure the alterations in key genes associated with cell death and cell cycle arrest. Our findings illustrated that both VPA and PGZ can inhibit Jurkat E6.1 cells in vitro after 24 hr; however, PGZ 400 μM presents the most anti-proliferative effect. Interestingly, treated cells have been arrested in G2/M with deregulated cell division cycle 25A (Cdc25A) phosphatase and cyclin-dependent kinase inhibitor 1B (CDKN1B or p27) expression. Expression of cyclin D1 gene was inhibited when DNA synthesis entry was declined. Cell cycle deregulation in PGZ and VPA-exposed cells generated an increase in the proportion of aneuploid cell population, which has not reported before. These findings define that anti-proliferative effects of PGZ and VPA on Jurkat cell line are mediated by cell cycle deregulation. Thus, we suggest PGZ and VPA may relieve potential therapeutic application against apoptosis-resistant malignancies.

Human phosphatase CDC14A is recruited to the cell leading edge to regulate cell migration and adhesion

Cell adhesion and migration are highly dynamic biological processes that play important roles in organ development and cancer metastasis. Their tight regulation by small GTPases and protein phosphorylation make interrogation of these key processes of great importance. We now show that the conserved dual-specificity phosphatase human cell-division cycle 14A (hCDC14A) associates with the actin cytoskeleton of human cells. To understand hCDC14A function at this location, we manipulated native loci to ablate hCDC14A phosphatase activity (hCDC14A(PD)) in untransformed hTERT-RPE1 and colorectal cancer (HCT116) cell lines and expressed the phosphatase in HeLa FRT T-Rex cells. Ectopic expression of hCDC14A induced stress fiber formation, whereas stress fibers were diminished in hCDC14A(PD) cells. hCDC14A(PD) cells displayed faster cell migration and less adhesion than wild-type controls. hCDC14A colocalized with the hCDC14A substrate kidney- and brain-expressed protein (KIBRA) at the cell leading edge and overexpression of KIBRA was able to reverse the phenotypes of hCDC14A(PD) cells. Finally, we show that ablation of hCDC14A activity increased the aggressive nature of cells in an in vitro tumor formation assay. Consistently, hCDC14A is down-regulated in many tumor tissues and reduced hCDC14A expression is correlated with poorer survival of patients with cancer, to suggest that hCDC14A may directly contribute to the metastatic potential of tumors. Thus, we have uncovered an unanticipated role for hCDC14A in cell migration and adhesion that is clearly distinct from the mitotic and cytokinesis functions of Cdc14/Flp1 in budding and fission yeast.

Genome editing through large insertion leads to the skipping of targeted exon.

BackgroundHighly efficient genome editing can be achieved through targeting an endonuclease to specific locus of interest. Engineered zinc-finger nuclease (ZFN) and CRISPR-associated protein-9 nuclease (Cas9) offer such an elegant approach for genome editing in vertebrate cells. In this study, we have utilized ZFN and Cas9-catalyzed double strand break followed by homologous recombination-mediated incorporation of premature stop codon and selection marker to target human cell division cycle 14A (hCDC14A) and cell division cycle 14B (hCDC14B) genes.ResultsTargeting of the hCDC14A and hCDC14B loci in telomerase immortalized human retinal pigment epithelium (hTERT-RPE1) and human colon cancer (HCT116) cells were confirmed by Southern blot hybridization. Nevertheless, DNA sequence analysis of reverse transcription polymerase chain reaction (RT-PCR) products confirmed that in all the single/double allele ablations, the targeted exon was spliced out. The phenomenon of exon skipping was independent of the genome editing approaches exploited, Cas9 or ZFN. Because the exons had a nucleotide number that could be divided by 3, the reading frame of the exon deletion was maintained. This indicates an exon-skipping event possibly due to the insertion of large DNA fragment (1.7 to 2.5 Kb) within the targeted exons. As a proof-of-principle, we have used gene disruption followed by non-homologous end joining (NHEJ) approach. Small alterations in the exon (one to fifteen bases) were transcribed to mRNA without exon skipping. Furthermore, loxP site-mediated removal of selection markers left a 45 bp scar within the targeted exon that can be traced in mRNA without exon skipping.ConclusionFrom this study, we conclude that insertion of a large DNA fragment into an exon by genome editing can lead to its skipping from the final transcript. Hence, more cautious approach needs to be taken while designing target sites in such that the possible skipping of targeted exon causes a frame-shift mediated incorporation of pre-mature stop codon. On the other hand, exon skipping may be a useful strategy for the introduction of protein deletions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-2284-8) contains supplementary material, which is available to authorized users.

Polychlorinated Biphenyl Quinone Metabolite Promotes p53-Dependent DNA Damage Checkpoint Activation, S-Phase Cycle Arrest and Extrinsic Apoptosis in Human Liver Hepatocellular Carcinoma HepG2 Cells.

Polychlorinated biphenyls (PCBs) are a group of persistent organic pollutants. The toxic behavior and mechanism of PCBs individuals and congeners have been extensively investigated. However, there is only limited information on their metabolites. Our previous studies have shown that a synthetic PCB metabolite, PCB29-pQ, causes oxidative damage with the evidence of cytotoxicity, genotoxicity, and mitochondrial-derived intrinsic apoptosis. Here, we investigate the effects of PCB29-pQ on DNA damage checkpoint activation, cell cycle arrest, and death receptor-related extrinsic apoptosis in human liver hepatocellular carcinoma HepG2 cells. Our results illustrate that PCB29-pQ increases the S-phase cell population by down-regulating cyclins A/D1/E, cyclin-dependent kinases (CDK 2/4/6), and cell division cycle 25A (CDC25A) and up-regulating p21/p27 protein expressions. PCB29-pQ also induces apoptosis via the up-regulation of Fas/FasL and the activation of caspase 8/3. Moreover, p53 plays a pivotal role in PCB29-pQ-induced cell cycle arrest and apoptosis via the activation of ATM/Chk2 and ATR/Chk1 checkpoints. Cell cycle arrest and apoptotic cell death were attenuated by the pretreatment with antioxidant N-acetyl-cysteine (NAC). Taken together, these results demonstrate that PCB29-pQ induces oxidative stress and promotes p53-dependent DNA damage checkpoint activation, S-phase cycle arrest, and extrinsic apoptosis in HepG2 cells.

MP36-08 MICRORNA-144-5P FUNCTIONS AS TUMOUR SUPPRESSOR THROUGH TARGETING CYCLIN E1 AND CYCLIN E2 THAT ARE POTENTIAL PROGNOSTIC MARKERS IN BLADDER CANCER

You have accessJournal of UrologyBladder Cancer: Basic Research I1 Apr 2015MP36-08 MICRORNA-144-5P FUNCTIONS AS TUMOUR SUPPRESSOR THROUGH TARGETING CYCLIN E1 AND CYCLIN E2 THAT ARE POTENTIAL PROGNOSTIC MARKERS IN BLADDER CANCER Ryosuke Matsushita, Naohiko Seki, Takeshi Chiyomaru, Satoru Inoguchi, Tomoaki Ishihara, Toshihiko Itesako, Shuichi Tatarano, Hirofumi Yoshino, Yusuke Goto, Rika Nishikawa, Hideki Enokida, and Masayuki Nakagawa Ryosuke MatsushitaRyosuke Matsushita More articles by this author , Naohiko SekiNaohiko Seki More articles by this author , Takeshi ChiyomaruTakeshi Chiyomaru More articles by this author , Satoru InoguchiSatoru Inoguchi More articles by this author , Tomoaki IshiharaTomoaki Ishihara More articles by this author , Toshihiko ItesakoToshihiko Itesako More articles by this author , Shuichi TataranoShuichi Tatarano More articles by this author , Hirofumi YoshinoHirofumi Yoshino More articles by this author , Yusuke GotoYusuke Goto More articles by this author , Rika NishikawaRika Nishikawa More articles by this author , Hideki EnokidaHideki Enokida More articles by this author , and Masayuki NakagawaMasayuki Nakagawa More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.736AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Our recent study of microRNA (miRNA) expression signature in bladder cancer (BC) revealed that miR-144-5p expression was significantly reduced in BC tissues, suggesting miR-144-5p function as a tumour suppressive miRNA in BC cells. The aim of this study was to investigate the functional significance of miR-144-5p and to identify its regulated oncogenic genes in BC. METHODS The expression levels of miR-144-5p and its candidate target genes were evaluated in BC cell lines (T24, BOY, J82, UMUC, and KK47) and BC clinical specimens (60 BCs and 22 normal bladder epitheliums: NBEs) by qRT-PCR methods. Gain-of-function studies (cell proliferation, migration, invasion, apoptosis, and cell cycle assays) were performed using transfection of mature miR-144-5p into cancer cells. Genome-wide gene expression analysis and in silico analysis were applied to investigate molecular targets regulated by miR-144-5p in BC cells. A luciferase reporter assay was carried out to determine whether 3′ UTR of target genes have actual biding sites for miR-144-5p. Overall survival (OS) of the BC patients was evaluated using the Kaplan-Meier method. RESULTS The expression levels of miR-144-5p was significantly reduced in BCs and BC cell lines compared to NBEs (P<0.0001). Restoration of miR-144-5p significantly inhibits cancer cell proliferation, migration, and invasion. Flow cytometry analysis revealed that G1 arrest was observed in miR-144-5p transfectants. Four cell cycle-related genes (cyclin E1; CCNE1, cyclin E2; CCNE2, cell division cycle 25A; CDC25A, and protein kinase, membrane associated tyrosine/threonine 1; PKMYT1) were identified for direct target genes of miR-144-5p by microarray and in silico studies, and luciferase reporter assays. Kaplan-Meier analysis showed that the patients with high CCNE1 and CCNE2 expressions had significantly shorter OS probability than those with low expressions of the genes (P=0.025 and 0.032). CONCLUSIONS Downregulation of miR-144-5p was frequent event of BC cells and its function as a tumour suppressor via targeting cell cycle-related genes such as CCNE1 and CCNE2. Overexpression of these genes might be contributed to progression of BC oncogenesis. Elucidation of tumour-suppressive miR-144-5p regulated molecular pathways and targets in BC cells could provide new information on potential diagnostic markers and therapeutic targets in BC. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e431-e432 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Ryosuke Matsushita More articles by this author Naohiko Seki More articles by this author Takeshi Chiyomaru More articles by this author Satoru Inoguchi More articles by this author Tomoaki Ishihara More articles by this author Toshihiko Itesako More articles by this author Shuichi Tatarano More articles by this author Hirofumi Yoshino More articles by this author Yusuke Goto More articles by this author Rika Nishikawa More articles by this author Hideki Enokida More articles by this author Masayuki Nakagawa More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Effects of age on follicular fluid exosomal microRNAs and granulosa cell transforming growth factor-β signalling during follicle development in the mare.

Age-related decline in fertility is a consequence of low oocyte number and/or low oocyte competence resulting in pregnancy failure. Transforming growth factor (TGF)-β signalling is a well-studied pathway involved in follicular development and ovulation. Recently, small non-coding RNAs, namely microRNAs (miRNAs), have been demonstrated to regulate several members of this pathway; miRNAs are secreted inside small cell-secreted vesicles called exosomes. The overall goal of the present study was to determine whether altered exosome miRNA content in follicular fluid from old mares is associated with changes in TGF-β signalling in granulosa cells during follicle development. Follicular fluid was collected at deviation (n=6), mid-oestrus (n=6) and preovulation (n=6) for identification of exosomal miRNAs from young (3-12 years) and old (20-26 years) mares. Analysis of selected TGF-β signalling members revealed significantly increased levels of interleukin 6 (IL6) in granulosa cells from mid-oestrus compared with preovulatory follicles, and collagen alpha-2(I) chain (COL1A2) in granulosa cells from deviation compared with preovulatory follicles in young mares. In addition, granulosa cells from old mares had significantly altered levels of DNA-binding protein inhibitor ID-2 (ID2), signal transducer and activator of transcription 1 (STAT1) and cell division cycle 25A (CDC25A). Finally, changes in exosomal miRNA predicted to target selected TGF-β members were identified.

Zipper-interacting protein kinase interacts with human cell division cycle 14A phosphatase.

Zipper‑interacting protein kinase (ZIPK) is a novel serine/threonine protein kinase and a member of a large family of protein kinases, known as the death‑associated protein kinases. However, the function of ZIPK has yet to be fully elucidated, as few physiological substrates have currently been identified. In the present study, a yeast two‑hybrid screen was used and the human cell division cycle 14A (HsCdc14A) phosphatase was identified as a novel ZIPK binding protein. To the best of our knowledge, this is the first study to report the interaction between these proteins. The interaction between ZIPK and HsCdc14A was confirmed by in vitro experiments. In addition, ZIPK‑mediated phosphorylation was shown to activate the phosphatase activity of HsCdc14A. These findings indicated that ZIPK may also be involved in the regulation of the cell cycle in human cells, by interacting with HsCdc14A.

MiR-141-3p inhibits human stromal (mesenchymal) stem cell proliferation and differentiation

Wnt signaling determines human stromal (mesenchymal) stem cell (hMSC) differentiation fate into the osteoblast or adipocyte lineage. microRNAs (miRNAs) are small RNA molecules of 21–25 nucleotides that regulate many aspects of osteoblast biology. Thus, we examined miRNAs regulated by Wnt signaling in hMSC. We identified miRNA (miR)-141-3p as a Wnt target which in turn inhibited Wnt signaling. Moreover, miR-141-3p inhibited hMSC proliferation by arresting cells at the G1 phase of the cell cycle. miR-141-3p inhibited osteoblast differentiation of hMSC as evidenced by reduced alkaline phosphatase activity, gene expression and in vitro mineralized matrix formation. Bioinformatic studies, Western blot analysis and 3’UTR reporter assay demonstrated that cell division cycle 25A (CDC25A) is a direct target of miR-141-3p. siRNA-mediated knock-down of CDC25A inhibited hMSC proliferation and osteoblast differentiation. In summary, miR-141-3p acts as a negative regulator of hMSC proliferation and osteoblast differentiation. Targeting miR-141-3p could be used as an anabolic therapy of low bone mass diseases, e.g. osteoporosis.

Inferring Transcriptional Regulatory Relationships Among Genes in Breast Cancer: An Application of Bayes' Theorem

The introduction of Deoxyribonucleic acid (DNA) microarray technologies provides a means of measuring the expression of thousands of genes simultaneously. It has generally sought to revolutionalize biological research by significantly elucidating biological processes. Gene networks may be inferred from such microarray data. Bayes' theorem, in this work is applied to the problem of inferring new transcriptional regulatory relationships among gene products in Breast Cancer. A compendium of human breast epithelial cell probe level microarray data from the Gene Expression Omnibus (GEO) repository was subjected to the Robust Multiarray Average (RMA) procedure for normalization and background correction. A subset of the resulting expression matrix consisting of the expression values of only relevant probe-set identifiers (IDs) representing the genes of interest in the data were extracted with a LISP code. This subset was supplied to a Bayesian Network inference learning algorithm to unearth new regulatory relationships from the data. Variations in parameters of the learning algorithms resulted in the prediction of at least 10 new relationships among genes in breast cancer. Among these were the direct regulatory signaling relationship between S-phase kinase associated protein 2 (SKP2) and the Cell division cycle 25A (CDC25A) and that between the cyclin-dependent kinases regulatory subunit 1 (CKS1B / CDC28) and E2F transcription factor 3 (E2F3). The identified causal networks are potentially useful for understanding complex drug actions and dysfunctional signaling in breast cancer.

The effect of zipper-interacting protein kinase on high glucose-stimulated human aortic smooth muscle cells

Biologic abnormalities in vascular smooth muscle cells (VSMC) may perform a crucial role in the pathogenesis of diabetic vascular disease. The principal aim of this study was to determine the effects of zipper-interacting protein kinase (ZIPK) on human aortic smooth muscle cells (HASMCs) stimulated by high glucose (HG). To elucidate the role of ZIPK in HG-treated HASMCs, we overexpressed ZIPK by lentivirus infection and knocked down ZIPK by gene deletion using ZIPK shRNA. Flow cytometry and Cell Counting kit-8 (CCK-8) were separately used to analyze cell apoptosis and proliferation. Migratory activity was examined using transwell migration chamber assays. The results showed that ZIPK overexpression inhibited cell growth and migration, enhanced cell apoptosis, and reversed cell cycle disturbance by regulating the related proteins of cellular physiological process, such as human cell division cycle 14A phosphatase (Hcdc14A) and intercellular adhesion molecule 1 (ICAM-1). In conclusion, the results suggested that ZIPK plays a role in HG-treated HASMCs, indicating ZIPK is a potential therapeutic target for the treatment of diabetic vascular complications.

The prognostic impact of 1p21 deletion on newly diagnosed multiple myeloma patients receiving thalidomide-based first-line treatment

To explore the deletion rate, clinical correlation and prognostic significance of 1p21 deletion, a novel genetic prognostic index, in patients with multiple myeloma (MM). The interphase fluorescence in situ hybridization (I-FISH) was performed on purified CD138⁺ plasma cells from 78 newly diagnosed patients from Sep 2007 to Sep 2012 receiving thalidomide-based chemotherapy by using BAC probe covered 1p21.2 region that contains the human cell division cycle 14A (HCDC14A) gene. Deletion rate, the cell percentage of deletion, clinical relevance and prognostic significance were analyzed in myeloma patients. Among 78 patients, there were 51 males and 27 females, the median age was 59(42-81). The deletion rate of 1p21.2 was 23.1%. Some patients had amplification (amp) of 1p with amp rate of 5.1% in 1p21.2, the amp rate was significantly lower than the deletion rate (P=0.001). 1p21.2 deletion was positively correlated with renal lesion (Cr≥177 μmol/L), high percentage of plasma cells in bone marrow, high LDH (≥220 U/L) and high β2-MG (P=0.014, 0.000, 0.010 and 0.022, respectively). With a median follow-up time of 15.0(1.0-53.5) months, the estimated median progressionfree survival (PFS) and overall survival (OS) time for patients with 1p21 deletion was (12.0±2.7) and (14.0±3.4) months, however those were (30.0±8.0) and (38.5±1.8) months in patients without 1p21 deletion, respectively (P=0.000). On multivariate analysis, which included complex karyotype, LDH≥220 U/L, renal lesion and del(17p13), 1p21 deletion remained as an independent risk factor for PFS (HR: 3.312, 95% CI: 1.095-10.017, P=0.034) and OS (HR: 4.961, 95% CI: 1.487-16.552, P=0.009). 1p21 deletion is an important genetic prognosis indicator in multiple myeloma patients.

CDC25AQ110del: A Novel Cell Division Cycle 25A Isoform Aberrantly Expressed in Non-Small Cell Lung Cancer

ObjectiveLung cancer remains number one cause of cancer related deaths worldwide. Cell cycle deregulation plays a major role in the pathogenesis of Non-Small Cell Lung Cancer (NSCLC). CDC25A represents a critical cell cycle regulator that enhances cell cycle progression. In this study we aimed to investigate the role of a novel CDC25A transcriptional variant, CDC25AQ110del, on the regulation of the CDC25A protein, and its impact on prognosis of NSCLC patients.Methodology/Principal FindingsHere we report a novel CDC25A transcript variant with codon 110 (Glutamine) deletion, that we termed CDC25AQ110del in NSCLC cells. In 9 (75%) of the 12 NSCLC cell lines, CDC25AQ110del expression accounted for more than 20% of the CDC25A transcripts. Biological effects of CDC25AQ110del were investigated in H1299 and HEK-293F cells using UV radiation, flowcytometry, cyclohexamide treatment, and confocal microscopy. Compared to CDC25Awt, CDC25AQ110del protein had longer half-life; cells expressing CDC25AQ110del were more resistant to UV irradiation and showed more mitotic activity. Taqman-PCR was used to quantify CDC25AQ110del expression levels in 88 primary NSCLC tumor/normal tissue pairs. In patients with NSCLC, Kaplan Meier curves showed tumors expressing higher levels of CDC25AQ110del relative to the adjacent lung tissues to have significantly inferior overall survival (P = .0018).SignificanceHere we identified CDC25AQ110del as a novel transcriptional variant of CDC25A in NSCLC. The sequence-specific nature of the abnormality could be a prognostic indicator in NSCLC patients as well as a candidate target for future therapeutic strategies.

Accelerated elimination of ultraviolet-induced DNA damage through apoptosis in CDC25A-deficient skin

Cell division cycle 25A (CDC25A) is a dual-specificity phosphatase that removes inhibitory phosphates from cyclin-dependent kinases, allowing cell-cycle progression. Activation of cell-cycle checkpoints following DNA damage results in the degradation of CDC25A, leading to cell-cycle arrest. Ultraviolet (UV) irradiation, which causes most skin cancer, results in both DNA damage and CDC25A degradation. We hypothesized that ablation of CDC25A in the skin would increase cell-cycle arrest following UV irradiation, allowing for improved repair of DNA damage and decreased tumorigenesis. Cdc25a(fl/fl) /Krt14-Cre recombinase mice, with decreased CDC25A in the epithelium of the skin, were generated and exposed to UV. UV-induced DNA damage, in the form of cyclopyrimidine dimers and 8-oxo-deoxyguanosine adducts, was eliminated earlier from CDC25A-deficient epidermis. Surprisingly, loss of CDC25A did not alter epidermal proliferation or cell cycle after UV exposure. However, the UV-induced apoptotic response was prolonged in CDC25A-deficient skin. Double labeling of cleaved caspase-3 and the DNA damage marker γH2A.X revealed many of the apoptotic cells in UV-exposed Cdc25a mutant skin had high levels of DNA damage. Induction of skin tumors by UV irradiation of Cdc25a mutant and control mice on a skin tumor susceptible to v-ras(Ha) Tg.AC mouse background revealed UV-induced papillomas in Cdc25a mutants were significantly smaller than in controls in the first 6 weeks following UV exposure, although there was no difference in tumor multiplicity or incidence. Thus, deletion of Cdc25a increased apoptosis and accelerated the elimination of DNA damage following UV but did not substantially alter cell-cycle regulation or tumorigenesis.

Cdc25A promotes cell survival by stimulating NF-κB activity through IκB-α phosphorylation and destabilization

Cell division cycle 25A (Cdc25A), a dual specificity protein phosphatase, exhibits anti-apoptotic activity, but the underlying molecular mechanisms are poorly characterized. Here we report that Cdc25A inhibits cisplatin-induced apoptotic cell death by stimulating nuclear factor-kappa B (NF-κB) activity. In HEK-293 cells, Cdc25A decreased protein level of inhibitor subunit kappa B alpha (Iκ-Bα) in association with increased serine 32-phosphorylation, followed by stimulation of transcriptional activity of NF-κB. Inhibition of NF-κB activity by chemical inhibitor or overexpression of Iκ-Bα in Cdc25A-elevated cancer cells resistant to cisplatin improved their sensitivity to cisplatin-induced apoptosis. Our data show for the first time that Cdc25A has an important physiological role in NF-κB activity regulation and it may be an important survival mechanism of cancer cells.