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Cyclin-dependent Kinase Inhibitor (cyclin-dependent + kinase_inhibitor)
Selected AbstractsImidazo[1,2-b]pyridazines: A Potent and Selective Class of Cyclin-Dependent Kinase Inhibitors.CHEMINFORM, Issue 35 2004Andrew P. Thomas Abstract For Abstract see ChemInform Abstract in Full Text. [source] Pyrazolo[4,3-d]pyrimidines as New Generation of Cyclin-Dependent Kinase Inhibitors.CHEMINFORM, Issue 51 2003Daniela Moravcova Abstract For Abstract see ChemInform Abstract in Full Text. [source] Cyclin-dependent kinase inhibitors for treating cancerMEDICINAL RESEARCH REVIEWS, Issue 6 2001Peter L. Toogood Abstract Cyclin dependent kinases (Cdks) are essential enzymes for the control of cell cycle progression. Inhibitors of cyclin-dependent kinases are anticipated to possess therapeutic utility against a wide variety of proliferative diseases, especially cancer. The field of published small molecule Cdk inhibitors is briefly reviewed here as background to a summary of work on a class of pyrido[2,3- d]pyrimidine Cdk inhibitors. Compounds from this class are described that display potency against cyclin D/Cdk4 up to IC50,=,0.004 ,M. Good to moderate selectivity for cyclin D/Cdk4 is also reported for compounds in this structural class. Structure-activity relationship data are presented for substitution at the C2 and N8 positions and these data are interpreted in the context of a binding model that is based on the Cdk2 crystal structure. A representative cyclin D/Cdk4 inhibitor (compound 56) is demonstrated to selectively inhibit the proliferation of an Rb+ cell line vs. a matched Rb, cell line and to produce a distinct G1 block consistent with cyclin D/Cdk4 inhibition in cells. © 2001 John Wiley & Sons, Inc. Med Res Rev, 21, No. 6, 487,498, 2001 [source] The expression patterns of Pax7 in satellite cells during overload-induced rat adult skeletal muscle hypertrophyACTA PHYSIOLOGICA, Issue 4 2009M. Ishido Abstract Aim:, Activated satellite cells (SCs) have the ability to reacquire a quiescent, undifferentiated state. Pax7 plays a crucial role in allowing activated SCs to undergo self-renewal. Because the increase in the SC population is induced during overload-induced skeletal muscle hypertrophy, it is possible that Pax7-regulated SC self-renewal is involved in the modulation of the SC population during the functional overload of skeletal muscles. However, the characteristics of the expression patterns of Pax7 in SCs during the functional overload of adult skeletal muscles are poorly understood. Methods:, Using immunohistochemical approaches, we examined the temporal and spatial expression patterns of Pax7 expressed in SCs during the functional overloading of rat skeletal muscles. Results:, The time course of Pax7 expression in SCs was similar to that of the expression of the differentiation regulatory factor myogenin during the early stage of functional overload. However, the percentage of SCs that expressed Pax7 was markedly higher than that of the SCs that expressed myogenin. Coexpression of Pax7 and myogenin was not detected in SCs. In addition, the expression of cyclin-dependent kinase inhibitor p21, which regulates cell cycle arrest and differentiation, was not detected in Pax7-positive SCs. Conclusion:, These results suggest that Pax7-regulated self-renewal of SCs may be induced during the early stage of functional overload and may contribute to modulating the SC population in hypertrophied muscles. Furthermore, it was suggested that the numbers of SCs which underwent self-renewal may be higher than that of SCs which were provided as the additional myonuclei for hypertrophying myofibres. [source] Human Papillomavirus and Overexpression of P16INK4a in Nonmelanoma Skin CancerDERMATOLOGIC SURGERY, Issue 3 2004Ingo Nindl PhD Background. P16INK4a overexpression has been identified as a specific biomarker in high-risk human papillomavirus (HPV),infected cervical (pre)cancer lesions. Objective. To evaluate the overexpression of this cyclin-dependent kinase inhibitor in skin tumors depending on HPV infections, we analyzed normal skin, benign skin disease, and skin cancer specimens. Methods. Biopsies of 23 patients with normal histology (3), psoriasis (2), verrucae vulgaris (2), actinic keratoses (5), squamous cell carcinoma (SCC) in situ (3), Bowen's carcinoma (1), and SCC (7) were analyzed. Specimens of 23 patients were immunostained using the monoclonal antibody E6H4 specific for p16INK4a. HPV status was assessed by a polymerase chain reaction (PCR) system to detect all currently known HPV types. MY (MY09/MY11 and MYN9/MYN10)-, CP (CP65/CP70 and CP66/CP69)-nested PCR, and three single PCR methods CN1, CN3, and CN4 were used in a first step, and HPV typing was performed by restriction fragment length polymorphism analysis. Only ,-globin,positive patients were included in this study. Results. HPV DNA was detected in all actinic keratoses, SCC in situ, Bowen's carcinoma, and SCC, in 50% (one of two) of verrucae vulgaris, in 66% (two of three) of normal skin, and in none of two psoriasis. P16INK4a expression was not detected in normal skin, psoriasis, and verrucae vulgares. Overexpression of p16INK4a was detected in a subset of dysplastic cells (10% to 80%) of all skin (pre)cancer lesions such as actinic keratoses, SCC in situ, Bowen's carcinoma, and SCC infected with HPV independent of sun exposure. Conclusion. P16INK4a appears to be overexpressed in a portion of dysplastic cells from actinic keratoses and SCC. Further studies to examine the association of HPV infection and the overexpression of p16INK4a are warranted. [source] Comparison of p16INK4A and Hybrid Capture® 2 human papillomavirus testing as adjunctive tests in liquid-based gynecologic SurePathÔ preparationsDIAGNOSTIC CYTOPATHOLOGY, Issue 3 2008Aziza Nassar M.D., F.I.A.C. Abstract p16INK4a, cyclin-dependent kinase inhibitor, is functionally inactivated in many tumors, including cervical cancer. We compared p16INK4A immunocytochemical staining and Hybrid Capture® 2 (HCII) on SurePathÔ specimens using tissue biopsies (as the gold standard). Their utility in a spectrum of atypical and preneoplastic lesions, and their ability to accurately identify underlying lesions of CIN II or greater was assessed using biopsy follow-up data. One-hundred and seventeen residual SurePathÔ samples were collected: 43 atypical squamous cells of undetermined significance (ASCUS), 47 low-grade (LGSIL), and 27 high-grade (HGSIL) squamous intraepithelial lesions. Two slides were prepared from each sample; one stained with the SurePathÔ autocyte stain and one immunostained using the CINtecÔ p16INK4a Cytology Kit (Dakocytomation). High-risk HPV testing was performed using the HCII DNA test (Digene, Gaithersburg, MD). Available tissue biopsy follow-up data was retrieved. p16INK4a was positive in 32.6% (14/43) ASCUS, 46.8% (22/47) LGSIL, and 48.1% (13/27) HGSIL specimens. HCII DNA test was positive in 41.9% (18/43) ASCUS, 78.7% (37/47) LGSIL, and 96.3% (26/27) HGSIL samples. The sensitivity, specificity, positive (PPV) and negative (NPV) predictive values of p16INK4a and HCII were: 58.7% and 89.8%, 58.6% and 34.6%, 69.2% and 72.1%, 47.2% and 64.3%, respectively. In patients with cervical biopsies, the PPV of HCII (92.3%) results for a biopsy with CINII/III was significantly higher than the PPV of p16INK4a (52%) (P = 0.001). Using liquid-based cytology specimens, HCII is a more sensitive test than p16INK4a for detection of abnormal cytology. HCII has a higher PPV than p16INK4a for identifying CIN II/III. Diagn. Cytopathol. 2008;36:142,148. © 2008 Wiley-Liss, Inc. [source] The histone deacetylase inhibitor MS-275 induces p21WAF1/Cip1 expression in human Hep3B hepatoma cellsDRUG DEVELOPMENT RESEARCH, Issue 2 2007Haiyuan Zhang Abstract MS-275 is a novel synthetic benzamide derivative histone deacetylase (HDAC) inhibitor, that has demonstrated antiproliferative activity in a variety of in vitro human cancer cell lines including breast, colon, lung, myeloma, ovary, pancreas, prostate, and leukemia. Currently, little information is available concerning the effects of MS-275 on liver cancer cells. In the current study, MS-275 was found to have potent actions against human hepatoma Hep3B cells including inhibition of cell proliferation and induction of apoptosis. MS-275 selectively up-regulated a cyclin-dependent kinase inhibitor, p21WAF1/Cip1 without alteration of p27WAF1. Expression of p21WAF1/Cip1 is considered to play a pivotal role in Hep3B cell growth arrest and induction of apoptosis. Induction of p21WAF1/Cip1 expression was accompanied by an accumulation of acetylated histones H3 and H4 associated specifically with p21WAF1/Cip1 gene. ChIP analysis revealed remarkable alterations in protein components bound to the promoter region of p21WAF1/Cip1 gene in response to MS-275 treatment. These included the degradation of HDAC1, HDAC3, and c-Myc, and as well as increased p300 and RNA polymerase II. The selective effect of MS-275 on the up-regulation of the p21WAF1/Cip1 gene whose expression was suppressed in the hepatoma cancer cell line indicated that it would be a very attractive approach in clinical liver cancer therapy. Drug Dev Res 68:61,70, 2007. © 2007 Wiley-Liss, Inc. [source] Prognostic value of p27kip1 expression in adenocarcinoma of the pancreatic head regionHPB, Issue 3 2006Jerzy Mielko Abstract Background. p27kip1 is a tumour suppressor gene, functioning as a cyclin-dependent kinase inhibitor, and an independent prognostic factor in breast, colon, and prostate adenocarcinomas. Conflicting data are reported for adenocarcinoma of the pancreas. The aim of this study was to establish the prognostic value of p27kip1 expression in adenocarcinoma of the pancreatic head region. Patients and methods. The study included 45 patients (male/female ratio 2:1; mean age 59, range 38,82 years) with adenocarcinomas of the pancreatic head region: 24 , pancreatic head, 18 , periampullary and 3 , uncinate process. The patients underwent the Kausch-Whipple pancreatoduodenectomy (n=39), pylorus-preserving pancreatoduodenectomy (n=5), or nearly total pancreatectomy (n=1). Eight patients received adjuvant chemotherapy postoperatively. Follow-up time ranged from 3 to 60 months. Tumours were staged according to the pTNM classification (UICC 1997). Immunohistochemistry was done on paraffin-embedded blocks from tumour sections. Quantitative determination of p27kip1 expression was based on the proportion of p27kip1 -positive cells (< 5%= negative). Survival analysis was carried out using the Kaplan-Meier method and Cox regression model. Results. Positive p27kip1 expression was detected in 22 tumours (49%), whereas 23 tumours (51%) were p27kip1 -negative. There were no significant correlations between p27kip1 index and stage or lymph node involvement. Median survival time in patients with p27kip1 -positive tumours was 19 months, whereas in patients with p27kip1 -negative tumours it was 18 months (p=0.53). A significant relationship was found between p27kip1 -negative tumours and radical resection (p=0.04). Multivariate survival analysis revealed that the localization of the tumour (pancreatic head/uncinate process vs periampullary) was the only significant and independent prognosticator (p=0.01, Cox regression model). Resection margins involvement and grade remained nearly significant prognostic factors (p=0.07 and p=0.09, respectively). Conclusion. We conclude that p27kip1 has limited overall prognostic utility in resected carcinoma of the pancreatic head region, but its potential role as a marker of residual disease needs to be further assessed. [source] Immunocytochemistry in liquid-based cervical cytology: Analysis of clinical use following a cross-sectional studyINTERNATIONAL JOURNAL OF CANCER, Issue 5 2006Shaira Sahebali Abstract Cytological screening for cervical cancer is hampered by imperfect sensitivity and low inter-observer reproducibility. Human papillomavirus (HPV) testing lacks specificity as a primary screening method. Studies indicate that immunocytochemical detection of alterations caused by HPV in the host cells can optimise screening. Here, the potential of p16INK4a (cyclin-dependent kinase inhibitor p16) and MIB-1 (Ki-67 proliferation marker) as adjunct molecular markers for cervical lesions was investigated in a prospective, cross-sectional study of 500 samples in the framework of opportunistic screening in Flanders, Belgium. A consecutive series of 200 samples and 100 samples from the cytological categories ASC, LSIL and HSIL were investigated. Surepath samples were interpreted according to the Bethesda 2001 reporting system. HPV testing was done with MY09/MY11 consensus PCR. Immunocytochemistry for p16INK4a and MIB-1 was performed with an automated staining protocol. The number of immunoreactive cells/1,000 cervical cells was assessed. There was a higher mean number of p16INK4A and MIB-1 immunoreactive cells/1,000 cells in HSIL (4.06 ± 1.93 and 11.13 ± 2.83, respectively) compared to other cytological categories. Both markers showed a large spread in counts, for all categories. In cases of HSIL without immunoreactive cells for either marker, low cellularity and long-term storage in water were often the cause of false negativity. This study confirms that positive staining for p16INK4a and MIB-1 is highly correlated with presence of high-grade lesions. These markers could be used as adjuncts to increase the sensitivity of cytological screening as well as the specificity of the HPV test. However, clear methodological standards are needed for optimal performance of immunocytochemistry in a clinical setting. © 2005 Wiley-Liss, Inc. [source] Green tea extracts decrease carcinogen-induced mammary tumor burden in rats and rate of breast cancer cell proliferation in cultureJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2001Kathryn T. Kavanagh Abstract Epidemiological evidence suggests tea (Camellia sinensis L.) has chemopreventive effects against various tumors. Green tea contains many polyphenols, including epigallocatechin-3 gallate (EGCG), which possess anti-oxidant qualities. Reduction of chemically induced mammary gland carcinogenesis by green tea in a carcinogen-induced rat model has been suggested previously, but the results reported were not statistically significant. Here we have tested the effects of green tea on mammary tumorigenesis using the 7,12-dimethylbenz(a)anthracene (DMBA) Sprague-Dawley (S-D) rat model. We report that green tea significantly increased mean latency to first tumor, and reduced tumor burden and number of invasive tumors per tumor-bearing animal; although, it did not affect tumor number in the female rats. Furthermore, we show that proliferation and/or viability of cultured Hs578T and MDA-MB-231 estrogen receptor-negative breast cancer cell lines was reduced by EGCG treatment. Similar negative effects on proliferation were observed with the DMBA-transformed D3-1 cell line. Growth inhibition of Hs578T cells correlated with induction of p27Kip1 cyclin-dependent kinase inhibitor (CKI) expression. Hs578T cells expressing elevated levels of p27Kip1 protein due to stable ectopic expression displayed increased G1 arrest. Thus, green tea had significant chemopreventive effects on carcinogen-induced mammary tumorigenesis in female S-D rats. In culture, inhibition of human breast cancer cell proliferation by EGCG was mediated in part via induction of the p27Kip1 CKI. J. Cell. Biochem. 82:387,398, 2001. © 2001 Wiley-Liss, Inc. [source] Immunohistochemical determination of the P15INK4b protein expression in cutaneous squamous cell carcinomaJOURNAL OF CUTANEOUS PATHOLOGY, Issue 2 2009Ahmed I. Moad The tumor suppressor gene p15INK4b is a cyclin-dependent kinase inhibitor, in which its inactivation has been determined in primary tumors and in several tumor-derived cell lines. The precise role of p15INK4b protein expression in cutaneous squamous cell carcinoma (SCC) is currently not known. In a previous study, we have shown the frequent occurrence of allelic imbalance/loss of heterozygosity in cutaneous SCC using two microsatellite markers flanking the p15INK4b gene. This study is a continuation of our previous study and aims to determine the possible role of p15INK4b protein expression in the genesis of cutaneous SCC. P15INK4b protein expression was determined using immunohistochemical approach in 107 cases of cutaneous SCC tissue arrays and 19 cases of normal human skin tissues. The expression of p15INK4b was significantly reduced in the cutaneous SCC cases as compared with normal human skin (p = 0.017 and p < 0.05). However, there were no significant relationship between clinicopathologic variables of the patients (age, sex and tumor grade) and p15INK4b protein expression. The absence of p15INK4b expression in the majority of tissue microarray cores of cutaneous SCC indicated that p15INK4b could possibly be involved in the pathogenesis of cutaneous SCC. [source] Dual effects of hepatitis C virus Core protein on the transcription of cyclin-dependent kinase inhibitor p21 geneJOURNAL OF VIRAL HEPATITIS, Issue 4 2003H. J. Kwun Summary. Transcription of p21 was activated in hepatitis C virus (HCV) Core-expressing HepG2 cells where its upstream p53 was stabilized. However, this effect was not absolutely required for the activation of p21 by Core, as demonstrated in Hep3B cells. In addition, an opposite effect on the transcription of p21 was observed in NIH3T3 and primary hepatocytes, where p53 was not decreased by Core. To explain the p53-independent regulation of p21 by Core, we identified a Core-responsive element between positions ,74 and ,83 of the p21 promoter, exactly overlapped with a tumour growth factor , (TGF- ,)/butyrate responsive element. Furthermore, we demonstrated that Core could activate the p21 through the element by stimulating a butyrate pathway, whereas this was inhibited through a TGF- , pathway. The opposing effects of Core protein on the transcription of p21 might be important in understanding the progression of hepatic disease in HCV-positive patients. [source] Hepatocyte senescence in end-stage chronic liver disease: a study of cyclin-dependent kinase inhibitor p21 in liver biopsies as a marker for progression to hepatocellular carcinomaLIVER INTERNATIONAL, Issue 5 2007Elizabeth M. Brunt Abstract Background: Histologic markers to predict hepatocellular carcinoma (HCC) include small cell change and dysplastic nodules. Hepatocyte senescence is noted in chronic liver disease and may or may not be important in progression to HCC. Aim: The study was undertaken to compare standard histologic features of chronic liver disease as well as markers of senescence and proliferation in two groups of biopsies from patients followed for at least a year. Methods: Standard histologic evaluation of necroinflammatory activity, fibrosis, steatosis, and iron, internationally accepted criteria of dysplasia, and immunohistochemical markers for proliferation and hepatocyte senescence were compared in 47 liver biopsies from noncholestatic chronic liver disease patients who subsequently either underwent transplant (the Control group, n=19) or had biopsy-proven (HCC group, n=28) over a similar time period of 34.9 months (mean) and 42.5 months (mean) respectively. Results: Both groups were predominantly men; the MELD score was higher, and mean age was less in the Control group (46.9 vs 53.8 years, P=0.01). Small cell change was not significantly different in the biopsies between the two groups; neither were grade, stage (Ishak scores), nor presence or location of iron. Steatosis was more common in the group that subsequently developed HCC (P=0.04). The MIB-1 proliferation index was greater in the biopsies from the Control group. The senescence marker p21, and the ratio of p21:MIB-1 were not statistically different between the two groups. However, a Spearman's rank correlation showed a linear correlation of p21/MIB-1 with a greater amount of dyplasia in the explant livers of Controls. Conclusions: These findings suggested the Control groups' livers maintained effective removal of cells from the cell cycle by overexpression of p21 and, while not ,protected' from significant involvement by dysplasia, may have been precluded from development of HCC. [source] Gene expression profile analysis of regenerating liver after portal vein ligation in rats by a cDNA microarray systemLIVER INTERNATIONAL, Issue 3 2004Y Nagano Abstract: Aims: We assessed changes in gene expression of hypertrophied liver after portal vein ligation (PL) in a test group of rats compared to a control group, which had the same size liver but no PL. Methods: The portal veins of the left and median lobes in the test group were ligated in an initial operation. Four days after the PL, the liver volume of the posterior caudate lobe (5%) increased two-fold and comprised 10% of the liver. A 90% hepatectomy was then performed, leaving only the hypertrophied posterior caudate lobe, and leaving the normal anterior and posterior caudate lobes (10%) in the control (sham) group. A comparison of the expression profiles between two groups was performed using cDNA microarrays and the hepatic ATP level was measured. Results: The survival rate for the PL group was significantly higher than for the sham group at 4 days after the hepatectomy (56.3% and 26.7%, P<0.05). Gene expression of cyclin D1, proliferating cell nuclear antigen, cyclin A and B was upregulated, and the cyclin-dependent kinase inhibitor was downregulated. Increases were observed in: (i) pyruvate dehydrogenase, the tricarboxylic acid cycle cycle regulator, (ii) acyl-CoA dehydrogenase, the oxidation regulator, and (iii) cytochrome oxidases, the oxidative phosphorylation regulator. Hepatic ATP concentration after hepatectomy was better maintained in the PL group than in the sham group (0.48±0.01 ,mol/ml vs. 0.33±0.01 ,mol/ml, P<0.05). Conclusion: The regenerating liver increased tolerance for extended hepatectomy compared to normal liver. It is believed that this is because the induced rapid regeneration of the remaining liver after hepatectomy increases ATP metabolism. [source] Alsterpaullone, a novel cyclin-dependent kinase inhibitor, induces apoptosis by activation of caspase-9 due to perturbation in mitochondrial membrane potential,MOLECULAR CARCINOGENESIS, Issue 4 2003Tyler Lahusen Abstract The majority of human neoplasms have aberrations in the retinoblastoma pathway due to hyperactivation of cyclin-dependent kinases (CDK). Based on this observation, novel small molecules, such as flavopiridol and UCN-01, are being developed and are currently being tested in the clinic. Efforts to develop CDK modulators led us to the discovery of a novel class of CDK inhibitors, the paullones [Cancer Res 1999;59:2566]. Initial studies demonstrated that paullones inhibit CDKs in vitro, thereby blocking cell-cycle progression. However, the exact mechanism for the antiproliferative effects of paullones was never explored. In this report, we demonstrate for the first time that the most potent paullone, alsterpaullone (Alp), induced apoptosis and promoted loss in clonogenicity in the Jurkat cell line. Alp caused early activation of both caspase-8 and -9, leading to cleavage of caspase-3 and poly(ADP-ribose) polymerase (PARP). Moreover, apoptosis by Alp was not associated with loss in anti-apoptotic proteins such as XIAP or BCL-XL. Pre-incubation with cell-permeable inhibitors z-Asp(OMe)-Glu(OMe)-Val-Asp(Ome)-fluoromethylketone and benzyloxycarbonyl-Val-Ala-Asp (OMe)-fluoromethylketone (ZVAD) blocked Alp-induced apoptosis. Moreover, the general caspase inhibitor ZVAD blocked the cleavage and activation of most caspases tested except caspase-9. Studies of mitochondrial membrane potential also demonstrated that Alp is able to disrupt mitochondrial potential in the presence of ZVAD, suggesting that the activation of caspase-9 by Alp follows mitochondrial perturbation. Pre-incubation of Jurkat cells with ZVAD did not prevent the depletion of cyclin D3, loss of CDK, or cell-cycle arrest by Alp. In summary, these experiments suggest that Alp activates caspase-9 via mitochondrial perturbation. Active caspase-9 cleaves and activates caspase-8 and caspase-3, leading to apoptosis. In the presence of the general caspase inhibitor ZVAD, the cell-cycle effects of Alp are unaltered while apoptosis is blocked, suggesting that the CDK effects of Alp are not sufficient for Alp-induced apoptosis. Additional studies with paullones are warranted to further characterize their preclinical effects and to explore their potential use in the clinical setting. Published 2003 Wiley-Liss, Inc. [source] Time-course Expression of DNA Repair-related Genes in Hepatocytes of Zebrafish (Danio rerio) After UV-B ExposurePHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 1 2009Juliana Z. Sandrini The objective of this study was to evaluate the time-course effects of UV-B exposure on expression of genes involved in the DNA repair system of zebrafish (Danio rerio) hepatocytes, a highly competent species in terms of damage repair induced by UV radiation. For gene expression analysis (RT-PCR), cells were exposed to 23.3 mJ cm,2 UV-B, which was the dose that affected viable cell number (reduction of 30% when compared with the control group) and produced no visual alteration on cell morphology. The early response observed (6 h) showed induction in the expression of the CDKI gene (cyclin-dependent kinase inhibitor) and genes related to DNA damage repair (mainly XPC and DDB2), while the late response observed (24 h) was more related to up-regulation of p53 and genes involved in cell cycle arrest (gadd45a, cyclinG1). In all times analyzed, the anti-apoptotic gene Bcl-2 was down-regulated. Another interesting result observed was the up-regulation of the Apex- 1 gene after UV-B exposure, which could indicate the induction of oxidative lesions in the DNA molecule. In conclusion, these results demonstrate an activation of the DNA repair system in hepatocytes of zebrafish exposed to UV-B radiation, mainly involving the participation of p53. [source] ORIGINAL ARTICLE: Leukocyte Activation and Circulating Leukocyte-Derived Microparticles in PreeclampsiaAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 5 2009Christianne A.R. Lok Problem, Preeclampsia shows characteristics of an inflammatory disease including leukocyte activation. Analyses of leukocyte-derived microparticles (MP) and mRNA expression of inflammation-related genes in leukocytes may establish which subgroups of leukocytes contribute to the development of preeclampsia. Method of Study, Blood samples were obtained from preeclamptic patients, normotensive pregnant and non-pregnant controls. sL-selectin and elastase were measured by ELISA. mRNA was isolated from leukocytes and gene expression was determined by multiplex ligation-dependent probe amplification (MLPA). MP were characterized by flow cytometry. Results, Altered concentrations of sL-selectin and elastase confirmed leukocyte activation in preeclampsia. These leukocytes showed up-regulation of Nuclear Factor of Kappa light chain gene enhancer in B Cells inhibitor (NF,B-1A) and cyclin-dependent kinase inhibitor (CDKN)-1A compared with normotensive pregnant women. interleukin-1 Receptor Antagonist (IL-1RA) and tumor necrosis factor (TNF)-R1 were increased compared with those in non-pregnant controls. Monocyte-derived MP were elevated in preeclamptic patients compared with pregnant women. The numbers of cytotoxic T-cell-derived and granulocyte-derived MP were elevated compared with those of non-pregnant women. Conclusion, Leukocytes are activated in preeclampsia. A pro-inflammatory gene expression profile is not prominent, although differences in mRNA expression can be detected. Increased levels of particular subsets of leukocyte-derived MP reflect activation of their parental cells in preeclampsia. [source] Expression of the cyclin-dependent kinase inhibitor p27kip-1 in benign naevi and correlation with Ki-67 proliferative indexBRITISH JOURNAL OF DERMATOLOGY, Issue 2 2005Article first published online: 23 FEB 200 No abstract is available for this article. [source] Activation of extracellular signal-regulated kinase (ERK) in G2 phase delays mitotic entry through p21CIP1CELL PROLIFERATION, Issue 4 2006S. Dangi In contrast, the role of extracellular signal-regulated kinase during G2 phase and mitosis (M phase) is largely undefined. Previous studies have suggested that inhibition of basal extracellular signal-regulated kinase activity delays G2 - and M-phase progression. In the current investigation, we have examined the consequence of activating the extracellular signal-regulated kinase pathway during G2 phase on subsequent progression through mitosis. Using synchronized HeLa cells, we show that activation of the extracellular signal-regulated kinase pathway with phorbol 12-myristate 13-acetate or epidermal growth factor during G2 phase causes a rapid cell cycle arrest in G2 as measured by flow cytometry, mitotic indices and cyclin B1 expression. This G2 -phase arrest was reversed by pre-treatment with bisindolylmaleimide or U0126, which are selective inhibitors of protein kinase C proteins or the extracellular signal-regulated kinase activators, MEK1/2, respectively. The extracellular signal-regulated kinase-mediated delay in M-phase entry appeared to involve de novo synthesis of the cyclin-dependent kinase inhibitor, p21CIP1, during G2 through a p53-independent mechanism. To establish a function for the increased expression of p21CIP1 and delayed cell cycle progression, we show that extracellular signal-regulated kinase activation in G2 -phase cells results in an increased number of cells containing chromosome aberrations characteristic of genomic instability. The presence of chromosome aberrations following extracellular signal-regulated kinase activation during G2 -phase was further augmented in cells lacking p21CIP1. These findings suggest that p21CIP1 mediated inhibition of cell cycle progression during G2/M phase protects against inappropriate activation of signalling pathways, which may cause excessive chromosome damage and be detrimental to cell survival. [source] Induction of G2/M phase arrest and apoptosis by a novel indoloquinoline derivative, IQDMA, in K562 cellsDRUG DEVELOPMENT RESEARCH, Issue 9 2006Yi-Hsiung Lin Abstract The indoloquinoline, IQDMA (N,-(11H-indolo[3,2-c]quinolin-6-yl)-N,N-dimethylethane-1,2-diamine), was identified as a novel antineoplastic agent with broad spectrum of antitumor activities against several human cancer cells. IQDMA-induced G2/M arrest was accompanied by up-regulation of the cyclin-dependent kinase inhibitors (CDKIs), p21 and p27, and down-regulation of Cdk1and Cdk2. IQDMA had no effect on the levels of cyclin A, cyclin B1, cyclin D3, or Cdc25C. IQDMA also increased apoptosis, as characterized by apoptotic body formation, increase of the sub G1 population and poly (ADP-ribose) polymerase (PARP) cleavage. Further mechanistic analysis demonstrated that IQDMA upregulated FasL protein expression, and kinetic studies showed the sequential activation of caspases-8, -3, and -9. Both caspase-8 and caspase-3 inhibitors, but not a caspase-9-specific inhibitor, suppressed IQDMA-induced cell death. These molecular alterations provide an insight into IQDMA-caused growth inhibition, G2/M arrest, and apoptotic death of K562 cells. Drug Dev. Res. 67:743,751, 2006. © 2006 Wiley-Liss, Inc. [source] Absence of p16 and p27 gene rearrangements and mutations in de novo myelodysplastic syndromesEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 3 2005Sotirios G. Papageorgiou Abstract:, Myelodysplastic syndromes (MDS) represent a group of clonal hematopoietic disorders characterized by dyshemopoiesis and frequent evolution to acute leukemia. Tumor suppressor gene inactivation may be involved in MDS pathogenesis. The two families of cyclin-dependent kinase inhibitors (CDKIs) (INK4 family of p15, p16, p18 and p19 and CIP/KIP family of p21, p27 and p57) that negatively regulate cell cycle progression are known tumor suppressor genes. To determine whether genetic alterations of p16 and p27 genes play an important role in MDS pathogenesis, we examined DNA from 51 patients classified as 17 refractory anemias (RA), four refractory anemias with ringed sideroblasts (RARS), 19 refractory anemias with an excess of blasts (RAEB), 5 refractory anemias with excess of blasts in transformation (RAEB-t) and 6 chronic myelomonocytic leukemias (CMML). Southern blot analysis detected no homozygous deletions of p16 and p27. Polymerase chain reaction,single-strand conformation polymorphism (PCR,SSCP) and sequencing did not reveal point mutations for both genes with the exception of two allelic polymorphisms, namely a C , G transition at 447 bp of p16exon3 and a T , A transition at 791 bp of p27exon1 genes. Our results suggest that mutations of p16 and p27 genes resulting in abnormal p16 and p27 proteins do not represent a mechanism of gene inactivation involved in the pathogenesis of MDS. [source] Survivin as a target for new anticancer interventionsJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 2 2005Nadia Zaffaroni Abstract Survivin is a member of the inhibitor of apoptosis protein (IAP) family, that has been implicated in both control of cell division and inhibition of apoptosis. Specifically, its anti-apoptosis function seems to be related to the ability to directly or indirectly inhibit caspases. Survivin is selectively expressed in the most common human neoplasms and appears to be involved in tumour cell resistance to some anticancer agents and ionizing radiation. On the basis of these findings survivin has been proposed and and attractive target for new anticancer interventions. Several preclinical studies have demonstrated that down-regulation of survivin expression/function, accomplished through the use of antisense oligonucleotides, dominant negative mutants, ribozymes, small interfering RNAs and cyclin-dependent kinase inhibitors, increased the apoptotic rate, reduced tumor-growth potential and sensitized tumor cells to chemotherapeutic drugs with different action mechanisms and ,-irradiation in in vitro and in vivo models of different human tumor types. [source] Wnt-3a and Wnt-3 differently stimulate proliferation and neurogenesis of spinal neural precursors and promote neurite outgrowth by canonical signalingJOURNAL OF NEUROSCIENCE RESEARCH, Issue 14 2010Monica D. David Abstract Wnt factors regulate neural stem cell development and neuronal connectivity. Here we investigated whether Wnt-3a and Wnt-3, expressed in the developing spinal cord, regulate proliferation and the neuronal differentiation of spinal cord neural precursors (SCNP). Wnt-3a promoted a sustained increase of SCNP proliferation and decreased the expression of cyclin-dependent kinase inhibitors. In contrast, Wnt-3 transiently enhanced SCNP proliferation and increased neurogenesis through ,-catenin signaling. Furthermore, both Wnt-3a and Wnt-3 stimulated neurite outgrowth in SCNP-derived neurons through ,-catenin- and TCF4-dependent transcription. Glycogen synthase kinase-3, inhibitors mimicked Wnt signaling and promoted neurite outgrowth in established cultures. We conclude that Wnt-3a and Wnt-3 factors signal through the canonical Wnt/,-catenin pathway to regulate different aspects of SCNP development. These findings may be of therapeutic interest for the treatment of neurodegenerative diseases and nerve injury. © 2010 Wiley-Liss, Inc. [source] Anticancer effects of zoledronic acid against human osteosarcoma cellsJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 6 2006B. Kubista Abstract Based on neoadjuvant chemotherapy, the prognosis of osteosarcoma patients has improved dramatically. However, due to therapy resistance in patient subgroups, the development of new treatment strategies is still of utmost importance. The aim of our study was to test the effects of the nitrogen-containing bisphosphonate zoledronic acid (ZOL) on osteosarcoma cell lines (N,=,9). Exposure to ZOL at low micromolar concentrations induced a dose- and time-dependent block of DNA synthesis and cell cycle progression followed by microfilament breakdown and apoptosis induction. The ZOL-induced cell cycle accumulation in S phase was accompanied by significant changes in the expression of cyclins and cyclin-dependent kinase inhibitors with a prominent loss of cyclin E and D1. ZOL not only inhibited growth but also migration of osteosarcoma cells. The mevalonate pathway intermediary geranyl-geraniol (GGOH) but not farnesol (FOH) significantly inhibited the anticancer effects of ZOL against osteosarcoma cells. Correspondingly, ZOL sensitivity correlated with the blockade of protein geranylgeranylation indicated by unprenylated Rap1. Overexpression of even high levels of P-glycoprotein, as frequently present in therapy-resistant osteosarcomas, did not impair the anticancer activity of ZOL. Summarizing, our data suggest that ZOL, which selectively accumulates in the bone, represents a promising agent to improve osteosarcoma therapy. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source] New established melanoma cell lines: genetic and biochemical characterization of cell division cycleJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 1 2003A Vozza ABSTRACT Background Cancer might be envisaged as the result of a genetic process causing the unregulated proliferation of a given cell as well as its inability to undergo differentiation and/or apoptosis. Alterations of genes regulating cell division cycle appear to play a key role in the development of human cancer. Objective On the bases of the above considerations, we decided to establish new cell lines from human melanoma specimens, in order to analyse the molecular alterations in primary preparations of malignant cells. Results The present paper describes two new established cell lines and their genetic and biochemical features. Both the melanoma cell lines show inactivation of the cyclin-dependent kinase inhibitor gene, CDKN2A/p16INK4A, thus demostrating that this alteration occurs in primary human melanomas. No other alterations were observable when we investigated several different cell cycle genes including those encoding cyclins, cyclin-dependent kinases and cyclin-dependent kinase inhibitors. Analyses at protein level by means of immunoblotting confirmed the results obtained at the genetic level. Moreover, the inducibility of a pivotal cyclin-dependent kinase inhibitor gene, namely p21CIP1 gene, was obtained by treating the cells with histone deacetylase inhibitors, namely butyrate and phenylbutyrate. Conclusions Our results suggest a primary role of cyclin-dependent kinase inhibitor genes inactivation in the origin of human melanoma and allow the proposal of new therapeutic strategies based on the transcriptional activation of p21CIP1 gene. [source] Systematic review: the application of molecular pathogenesis to prevention and treatment of oesophageal adenocarcinomaALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 11 2007C. J. PETERS Summary Background Oesophageal adenocarcinoma is an increasingly common cancer with a poor prognosis. It develops in a stepwise progression from Barrett's metaplasia to dysplasia, and then adenocarcinoma followed by metastasis. Aim To outline the key molecular changes in oesophageal adenocarcinoma and to summarize the chemopreventative and therapeutic strategies proposed. Methods A literature search was performed to identify appropriate research papers in the field. Search terms included: Barrett's (o)esophagus, intestinal metaplasia, (o)esophageal adenocarcinoma, molecular changes, genetic changes, pathogenesis, chemoprevention, therapeutic strategies and treatment. The search was restricted to English language articles. Results A large number of molecular changes have been identified in the progression from Barrett's oesophagus to oesophageal adenocarcinoma although there does not appear to be an obligate order of events. Potential chemoprevention strategies include acid suppression, anti-inflammatory agents and antioxidants. In established adenocarcinoma, targeted treatments under evaluation include receptor tyrosine kinase inhibitors of EGFR and cyclin-dependent kinase inhibitors, which may benefit a subgroup of patients. Conclusions Advances in molecular methodology have led to a greater understanding of the oesophageal adenocarcinoma pathways, which provides opportunities for chemoprevention and therapeutic strategies with a mechanistic basis. More work is required to assess both the safety and efficacy of these new treatments. [source] p19Ink4d and p18Ink4c cyclin-dependent kinase inhibitors in the male reproductive axisMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 8 2007Gregory M. Buchold Abstract The loss of the cyclin-dependent kinase inhibitors (CKIs) p18Ink4c and p19Ink4d leads to male reproductive defects (Franklin et al., 1998. Genes Dev 12: 2899,2911; Zindy et al., 2000. Mol Cell Biol 20: 372,378; Zindy et al., 2001. Mol Cell Biol 21: 3244,3255). In order to assess whether these inhibitors directly or indirectly affect male germ cell differentiation, we examined the expression of p18Ink4c and p19Ink4d in spermatogenic and supporting cells in the testis and in pituitary gonadotropes. Both p18Ink4c and p19Ink4d are most abundant in the testis after 18 days of age and are expressed in purified populations of spermatogenic and testicular somatic cells. Different p18Ink4c mRNAs are expressed in isolated spermatogenic and Leydig cells. Spermatogenic cells also express a novel p19Ink4d transcript that is distinct from the smaller transcript expressed in Sertoli cells, Leydig cells and in other tissues. Immunohistochemistry detected significant levels of p19Ink4d in preleptotene spermatocytes, pachytene spermatocytes, condensing spermatids, and Sertoli cells. Immunoprecipitation-Western analysis detected both CKI proteins in isolated pachytene spermatocytes and round spermatids. CDK4/6-CKI complexes were detected in germ cells by co-immunoprecipitation, although the composition differed by cell type. p19Ink4d was also identified in FSH+ gonadotrophs, suggesting that this CKI may be independently required in the pituitary. Possible cell autonomous and paracrine mechanisms for the spermatogenic defects in mice lacking p18Ink4c or p19Ink4d are supported by expression of these CKIs in spermatogenic cells and in somatic cells of the testis and pituitary. Mol. Reprod. Dev. 74: 997,1007, 2007. © 2007 Wiley-Liss, Inc. [source] Mice lacking cyclin-dependent kinase inhibitor p19Ink4d show strain-specific effects on male reproductionMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 8 2007Gregory M. Buchold Abstract p19Ink4d is a member of the INK4 family of cyclin-dependent kinase inhibitors, which are important negative regulators of the G1-phase cyclin-dependent kinases CDK4 and CDK6. On a mixed C57BL/6,×,129P2/OlaHsd background, mice deficient for p19Ink4d exhibited defects in male reproductive function including testicular atrophy, alteration in serum follicle stimulating hormone, qualitative increase in germ cell apoptosis, and delayed kinetics of meiotic prophase markers (Zindy et al., 2001. Mol Cell Biol 21:3244,3255; Zindy et al., 2000. Mol Cell Biol 20:372,378). In this study, a quantitative assessment of these aspects of reproductive capacity demonstrated relatively mild deficits in p19Ink4d,/, males compared to controls. These effects did not dramatically worsen in older males although some seminiferous tubule defects were observed. Following marker-assisted backcrossing into the C57BL/6 background, p19Ink4d,/, males did not display defects in testis weights, sperm numbers, serum FSH, germ cell apoptosis, or kinetics of selected meiotic prophase markers. These studies indicate that a reduction in Ink4 family function by the loss of p19Ink4d is sufficient to induce mild reproductive defects in male mice with a mixed genetic background, but not in the C57BL/6 genetic background. Mol. Reprod. Dev. 74: 1008,1020, 2007. © 2007 Wiley-Liss, Inc. [source] ,B-crystallin is mutant B-RAF regulated and contributes to cyclin D1 turnover in melanocytic cellsPIGMENT CELL & MELANOMA RESEARCH, Issue 2 2010Rong Hu Summary The serine/threonine kinase, B-RAF, is frequently mutated in melanoma and is required for cell proliferation. Proteasomal turnover of cyclins and cyclin-dependent kinase inhibitors via E3 ubiquitin ligases regulates cell cycle progression. We previously showed that B-RAF regulates Cks1, a co-factor for the F-box protein Skp2. Recently, a second F-box protein cofactor was identified, ,B-crystallin, that binds Fbx4 and promotes cyclin D1 degradation. Here, we demonstrate that ,B-crystallin is down-regulated in mutant B-RAF melanoma cells compared to melanocytes in a B-RAF and MEK-dependent manner. In a subset of lines, MEK inhibition was sufficient to up-regulate ,B-crystallin protein levels; whereas in other lines combined MEK and proteasome inhibition was required. ,B-crystallin knockdown partially stabilized cyclin D1 in melanocytes. Expression of ,B-crystallin in mutant B-RAF melanoma cells did not promote cyclin D1 turnover under normal conditions, but did enhance turnover following etoposide-induced DNA damage. Together, these data show that ,B-crystallin is highly expressed in melanocytes contributing, in part, to cyclin D1 turnover. Furthermore, ,B-crystallin is down-regulated in a B-RAF-dependent manner in melanoma cells and its re-expression regulates cyclin D1 turnover after DNA damage. [source] Cell cycle analysis and expression of cell cycle regulator genes in myeloma cells overexpressing cyclin D1BRITISH JOURNAL OF HAEMATOLOGY, Issue 3 2001Kenichiro Yata Among the recently discovered myeloma-specific gene alterations associated with chromosomal translocations, cyclin D1/PRAD1/Bcl-1 overexpression caused by t(11;14)(q13;q32) is considered to be the most frequent in myeloma patients and cell lines, and may be a prognostic factor clinically. To elucidate the cellular biological role of overexpressed cyclin D1 in myeloma cells, we examined the mRNA expression levels of cell cycle regulators including three cyclin Ds, cyclin-dependent kinase inhibitors (CDK-Is) and accelerators. Cyclin D1 overexpression was clearly demonstrated in the lines with abnormal 11q13 and associated with overexpression of S and G2 accelerator genes. The cyclin D1 -overexpressing lines tended to have a shortened G1 phase compared with the non-expressing lines. In addition, artificial silencing using antisense oligonucleotides for cyclin D1 suppressed the growth rate of some but not all cyclin D1 -overexpressing cells. These results indicate that overexpression of cyclin D1 caused by cytogenetic abnormalities may make cells progress through the cell cycle rapidly, but it seems that other factors such as cyclin D2 and translocation-related genes affect the cell cycle progression in myeloma cells. [source] | |||||||||||||||||||||||||||||||