PEDIATRIC BLOOD & CANCER, Issue 2 2001
Margaret H. Collins MD
Abstract Background Most alveolar rhabdomyosarcomas (ARMS) have chromosome translocations and resultant gene fusion products. The more common translocation fuses the PAX3 and FKHR genes; patients who have PAX3-FKHR-positive ARMS have reduced event-free survival compared to patients with ARMS containing the less common translocation that fuses the PAX7 and FKHR genes. Procedure We examined histology, immunohistochemical markers of differentiation, and cell cycle characteristics of a panel of ARMS containing either PAX3-FKHR or PAX7-FKHR transcript to determine if these features differ between the ARMS subsets. Results Cell cycle parameters varied significantly: the number of nuclei that stained with either an immunohistochemical marker of proliferation (MIB1), or a TUNEL-based assay for apoptosis was significantly greater in tumors that expressed PAX3-FKHR compared to tumors that expressed PAX7-FKHR transcript. Conclusions We conclude that compared to PAX7-FKHR-containing tumors, ARMS that contain PAX3-FKHR transcript have (1) increased cell proliferation, consistent with greater loss of cell cycle regulation, and (2) apoptosis that is increased but insufficient to prevent tumor formation. More marked cell cycle dysregulation may contribute to poorer prognosis for patients with ARMS that have PAX3-FKHR fusion. Med Pediatr Oncol 2001;37:83,89. © 2001 Wiley-Liss, Inc. [source]

Expression and distribution of distinct variants of E-MAP-115 during proliferation and differentiation of human intestinal epithelial cells

CYTOSKELETON, Issue 4 2003
Marie-Thérèse Vanier
Abstract Epithelial cell proliferation and differentiation occur concomitant with striking remodeling of the cytoskeleton. Microtubules (MTs) play important roles in these processes, during which the MTs themselves are reorganized and stabilized by microtubule-associated proteins (MAPs). Among the proteins classified as structural MAPs, E-MAP-115 (also named ensconsin) is preferentially expressed in cells of epithelial origin. The aims of this study were, first, to determine if E-MAP-115, like other MAPs, is expressed as different isoforms during differentiation and, second, to perform a detailed analysis of the expression and distribution of any E-MAP-115 variants detected in intestinal epithelial cells during their polarization/differentiation. It was our expectation that these data would help us to develop hypotheses concerning the role of this MAP in epithelial development. We report the expression of three E-MAP-115 transcripts encoding isoforms of 115, 105, and 95 kDa; two display an expression gradient inverse to the third one as Caco-2 cells progress from proliferation through the stages of differentiation. To monitor the proteins produced from each transcript, we used purified polyclonal antibodies against synthetic peptides contained within the 115, 105, and 95 kDa isoforms to assay proliferating and differentiating CaCo-2 cells. Our results indicate that the expression and MT-binding capacity of the 115, 105, and 95 kDa isoforms vary upon proliferation/differentiation of the cells. E-MAP-115 proteins colocalize with MTs in proliferative and differentiated Caco-2 cells; in vivo, they are expressed in both crypt and villus epithelial cells where they are mainly concentrated at the apical pole of the cells. Cell Motil. Cytoskeleton 55:221,231, 2003. © 2003 Wiley-Liss, Inc. [source]

E2f6 and Bmi1 cooperate in axial skeletal development

DEVELOPMENTAL DYNAMICS, Issue 5 2008
Maria Courel
Abstract Bmi1 is a Polycomb Group protein that functions as a component of Polycomb Repressive Complex 1 (PRC1) to control axial skeleton development through Hox gene repression. Bmi1 also represses transcription of the Ink4a-Arf locus and is consequently required to maintain the proliferative and self-renewal properties of hematopoietic and neural stem cells. Previously, one E2F family member, E2F6, has been shown to interact with Bmi1 and other known PRC1 components. However, the biological relevance of this interaction is unknown. In this study, we use mouse models to investigate the interplay between E2F6 and Bmi1. This analysis shows that E2f6 and Bmi1 cooperate in the regulation of Hox genes, and consequently axial skeleton development, but not in the repression of the Ink4a-Arf locus. These findings underscore the significance of the E2F6,Bmi1 interaction in vivo and suggest that the Hox and Ink4a-Arf loci are regulated by somewhat different mechanisms. Developmental Dynamics 237:1232-1242, 2008. © 2008 Wiley-Liss, Inc. [source]

Growth defect in Grg5 null mice is associated with reduced Ihh signaling in growth plates

DEVELOPMENTAL DYNAMICS, Issue 1 2002
Wen-Fang Wang
Abstract Gene-targeted disruption of Grg5, a mouse homologue of Drosophila groucho (gro), results in postnatal growth retardation in mice. The growth defect, most striking in approximately half of the Grg5 null mice, occurs during the first 4,5 weeks of age, but most mice recover retarded growth later. We used the nonlinear mixed-effects model to fit the growth data of wild-type, heterozygous, and Grg5 null mice. On the basis of preliminary evidence suggesting an interaction between Grg5 and the transcription factor Cbfa1/Runx2, critical for skeletal development, we further investigated the skeleton in the mice. A long bone growth plate defect was identified, which included shorter zones of proliferative and hypertrophic chondrocytes and decreased trabecular bone formation. This decreased trabecular bone formation is likely caused by a reduced recruitment of osteoblasts into the growth plate region of Grg5 null mice. Like the growth defect, the growth plate and trabecular bone abnormality improved as the mice grew older. The growth plate defect was associated with reduced Indian hedgehog expression and signaling. We suggest that Grg5, a transcriptional coregulator, modulates the activities of transcription factors, such as Cbfa1/Runx2 in vivo to affect Ihh expression and the function of long bone growth plates. © 2002 Wiley-Liss, Inc. [source]

Role of leptin in the cardiovascular and endocrine complications of metabolic syndrome

DIABETES OBESITY & METABOLISM, Issue 6 2006
Marcelo L. G. Correia
Aim:, To review the potential role of leptin, hyperleptinaemia and leptin resistance in the cardiovascular and endocrine complications of metabolic syndrome. Methods:, Review of literature listed in Medline. Results:, Hyperleptinaemia is common in obesity and reflects increased adiposity and leptin resistance. Nevertheless, leptin resistance may not be complete as several actions of leptin, such as cardiovascular sympatho-activation, might be preserved in obese subjects known to be resistant to the metabolic effects of leptin (i.e. selective leptin resistance). Notably, the renal and sympathetic actions of leptin may play an important role in the pathogenesis of hypertension related to obesity and metabolic syndrome. Furthermore, the lipotoxic effect of leptin resistance may cause insulin resistance and , cell dysfunction, increasing the risk of type 2 diabetes. Leptin has also been shown to possess proliferative, pro-inflammatory, pro-thrombotic, and pro-oxidative actions. Conclusion:, Hyperleptinaemia and leptin resistance may contribute to hypertension, impaired glucose metabolism, and pro-atherogenic state in obesity and metabolic syndrome. [source]

Appraising the mitogenicity of insulin analogues relative to human insulin,response to: Weinstein D, Simon M, Yehezkel E, Laron Z, Werner H. Insulin analogues display IGF-I-like mitogenic and anti-apoptotic activity in cultured cancer cells.

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 3 2010
Diabetes Metab Res Rev 2009; 25(1): 4
Abstract Interest in mitogenic and potentially carcinogenic effects of insulin and insulin analogues has been renewed by several recent publications that have examined the relationship between cancer and insulin analogues. Actions mediated through the insulin-like growth factor-I receptor in a hyperinsulinaemic state have been implicated mechanistically. Both type 2 diabetes and endogenously elevated insulin-like growth factor-I have been epidemiologically linked to malignancies. Therefore, in vitro mitogenic effects and binding affinities of the various analogues have been analysed. A recent publication by Weinstein et al. studied the in vitro mitogenic and anti-apoptotic activities of insulin analogues, and their conclusion asserts that insulins glargine, detemir, and lispro displayed proliferative and anti-apoptotic effects in a number of malignant cell lines. However, their conclusions are not supported by the data which are not complete and lack clear statistical significance. This data should be interpreted cautiously in light of all other presently available scientific evidence. Prospective, randomized clinical trials will best address any direct relationship between insulin analogues and cancer. Until those studies are designed and completed, clinicians should consider the demonstrated strong benefit of glycaemic control in balance with any alleged risk. Copyright © 2010 John Wiley & Sons, Ltd. [source]

NF-,B and apoptosis in colorectal tumourigenesis

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 5 2007
M. M. Aranha
Abstract Background, Nuclear factor-,B (NF-,B) may play an important role in colorectal tumourigenesis, controlling cell cycle and apoptosis gene expression. In addition, imbalances between cell proliferation and cell death are thought to underlie neoplastic development. The aims of this study were to investigate apoptosis and expression of several apoptosis-related proteins, and to determine correlations with colorectal tumour progression. Materials and methods, Apoptosis was evaluated by the TUNEL assay in 48 patient samples, including adenomas, adenocarcinomas and adjacent normal mucosas. Immunohistochemistry was performed for Bcl-2 and NF-,B. Expression levels of p53, Bax and I,B proteins were determined by immunoblotting. Cultured human colon cancer cells were used to evaluate NF-,B expression and nuclear translocation by immunocytochemistry and immunoblotting. Results, Apoptosis and NF-,B immunoreactivity were significantly higher in tumour tissue compared with normal mucosa (P < 0·01), increasing in association with histological tumour progression (P < 0·01). Bcl-2 was consistently higher in normal mucosa (P < 0·01) and inversely correlated with the percentage of apoptosis (P < 0·01). Phosphorylated p53 and Bax levels were similar in tumour tissue and normal mucosa; however, the NF-,B inhibitor, I,B, tended to decrease in tumours. In vitro, nuclear translocation of NF-,B was greater in proliferative than in resting phases of colon cancer cells. Conclusions, NF-,B expression and apoptosis are increased from adenoma to poorly differentiated adenocarcinoma tissues. Apoptosis is correlated with suppression of Bcl-2 expression, but appears to proceed through a p53- and Bax-independent pathway. Activation of NF-,B may play an important role in colorectal tumour progression. [source]

Multiple functions of human T cells generated by experimental malaria challenge

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2009
Stephen M. Todryk
Abstract Protective immunity generated following malaria infection may be comprised of Ab or T cells against malaria Ag of different stages; however, the short-lived immunity that is observed suggests deficiency in immune memory or regulatory activity. In this study, cellular immune responses were investigated in individuals receiving Plasmodium falciparum sporozoite challenge by the natural (mosquito bite) route as part of a malaria vaccine efficacy trial. Parasitemia, monitored by blood film microscopy and PCR, was subsequently cleared with drugs. All individuals demonstrated stable IFN-,, IL-2 and IL-4 ex vivo ELISPOT effector responses against P. falciparum -infected RBC (iRBC) Ag, 28 and 90,days after challenge. However, infected RBC-specific central memory responses, as measured by IFN-, cultured ELISPOT, were low and unstable over time, despite CD4+ T cells being highly proliferative by CFSE dilution, and showed an inverse relationship to parasite density. In support of the observation of poor memory, co-culture experiments showed reduced responses to common recall Ag, indicating malaria-specific regulatory activity. This activity could not be accounted for by the expression of IL-10, TGF-,, FOXP3 or CTLA-4, but proliferating T cells expressed high levels of CD95, indicating a pro-apoptotic phenotype. Lastly, there was an inverse relationship between FOXP3 expression, when measured 10 days after challenge, and ex vivo IFN-, measured more than 100 days later. This study shows that malaria infection elicits specific Th1 and Th2 effector cells, but concomitant weak central memory and regulatory activity, which may help to explain the short-lived immunity observed. [source]

IL-22 and inflammation: Leukin' through a glass onion

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 12 2008
Lauren A. Zenewicz
Abstract IL-22 is a Th17,T-cell-associated cytokine that is highly expressed during chronic inflammation. IL-22 receptor expression is absent on immune cells, but is instead restricted to the tissues, providing signaling directionality from the immune system to the tissues. Through Stat3 signaling, IL-22 induces a variety of proliferative, anti-apoptotic, and anti-microbial pathways. IL-22 is bi-functional with both pro-inflammatory and protective effects on tissues depending on the inflammatory context. The cytokine plays a role both in the host response against extracellular pathogens and in the inflammation associated with autoimmune diseases. Therapeutics targeting IL-22 therefore may have promise for treating various chronic inflammatory diseases. [source]

The RhoA- and CDC42-specific exchange factor Dbs promotes expansion of immature thymocytes and deletion of double-positive and single-positive thymocytes

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2004

Abstract Specific members of the Rho family of GTPases exert unique influences on thymocyte proliferation, differentiation and deletion. Dbs is a guanine nucleotide exchange factor which is expressed throughout thymocyte development and is able to activate the Rho family GTPases CDC42, RhoA and RhoG. Transgenic mice expressing an activated form of Dbs had increased numbers of double-negative thymocytes. The Dbs transgene promoted expansion of double-negative thymocytes in the absence of pre-TCR, but had no effect on pre-TCR-dependent differentiation of double-negative thymocytes into double-positive thymocytes. Transgenic double-positive thymocytes were proliferative in vivo, but were also susceptible to apoptosis in vivo and in vitro. The transgenic single-positive thymocytes had attenuated proliferative responses following TCR ligation, and were depleted rather than expanded during culture in the presence of anti-CD3. When expressing a positively selectable TCR, transgenic double-positive thymocytes were increased in number and activated, but the output of single-positive thymocytes was reduced. Transgenic double-positive thymocytes were acutely sensitive to deletion by TCR ligation in vivo. These results indicate that activation of Dbs has the potential to promote proliferation throughout thymocyte development, but also sensitizes double-positive and single-positive thymocytes to deletion. [source]

Differentiation-dependent sensitivity to cell death induced in the developing retina by inhibitors of the ubiquitin-proteasome proteolytic pathway

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2001
D. D. C. Neves
Abstract The effects of inhibitors of proteasome function were studied in the retina of developing rats. Explants from the retina of neonatal rats at postnatal day (P) 3 or P6 were incubated with various combinations of the proteasome inhibitor carbobenzoxyl-leucinyl-leucinyl-leucinal (MG132), the protein synthesis inhibitor anisomycin, or the adenylyl cyclase activator forskolin. MG132 induced cell death in a subset of cells within the neuroblastic (proliferative) layer of the retinal tissue. The cells sensitive to degeneration induced by either MG132 or anisomycin, were birthdated by bromodeoxyuridine injections. This showed that the MG132-sensitive population includes both proliferating cells most likely in their last round of cell division, and postmitotic undifferentiated cells, at a slightly earlier stage than the population, sensitive to anisomycin-induced cell death. The results show that sensitivity to cell death induced by proteasome inhibitors defines a window of development in the transition from the cell cycle to the differentiated state in retinal cells. [source]

PERSPECTIVE: EMBEDDED MOLECULAR SWITCHES, ANTICANCER SELECTION, AND EFFECTS ON ONTOGENETIC RATES: A HYPOTHESIS OF DEVELOPMENTAL CONSTRAINT ON MORPHOGENESIS AND EVOLUTION

EVOLUTION, Issue 5 2003
Kathryn D. Kavanagh
Abstract The switch between the cell cycle and the progress of differentiation in developmental pathways is prevalent throughout the eukaryotes in all major cell lineages. Disruptions to the molecular signals regulating the switch between proliferative and differentiating states are severe, often resulting in cancer formation (uncontrolled proliferation) or major developmental disorders. Uncontrolled proliferation and developmental disorders are potentially lethal defects in the developing animal. Therefore, natural selection would likely favor a tightly controlled regulatory mechanism to help prevent these fundamental defects. Although selection is usually thought of as a consequence of environmental or ecological influences, in this case the selective force to maintain this molecular switch is internal, manifested as a potentially lethal developmental defect. The morphogenetic consequences of this prevalent, deeply embedded, and tightly controlled mechanistic switch are currently unexplored, however experimental and correlative evidence from several sources suggest that there are important consequences on the control of growth rates and developmental rates in organs and in the whole animal. These observations lead one to consider the possibility of a developmental constraint on ontogenetic rates and morphological evolution maintained by natural selection against cancer and other embryonic lethal defects. [source]

E6* oncoprotein expression of human papillomavirus type-16 determines different ultraviolet sensitivity related to glutathione and glutathione peroxidase antioxidant defence

EXPERIMENTAL DERMATOLOGY, Issue 6 2005
Stéphane Mouret
Abstract:, Clinical observations of non-melanoma skin cancer in immunocompromised patients, such as organ transplant recipients, suggest co-operative effects of human papillomavirus (HPV) and ultraviolet (UV) radiation. The aim of the present study is to evaluate UV sensitivity and DNA damage formation according to antioxidant status in HPV16-infected keratinocytes. We used SKv cell lines, infected with HPV16 and well characterized for their proliferative and tumorigenic capacities. We showed that SKv cell lines presented various E6* (a truncated form of E6) RNA levels. We demonstrated that the higher oncoprotein RNA expression level was associated with a higher resistance to solar-simulated radiation, more specifically to UVB radiation and to hydrogen peroxide. Moreover, this high resistance was associated with a low oxidative DNA damage formation after UV radiation and was related to high glutathione content and glutathione peroxidase activities. Therefore, the results of our study suggest that E6* levels could modulate the glutathione/glutathione peroxidase pathway providing a mechanism to protect HPV-infected keratinocytes against an environmental oxidative stress, such as UV radiation. [source]

Scaffold-Mediated 2D Cellular Orientations for Construction of Three Dimensionally Engineered Tissues Composed of Oriented Cells and Extracellular Matrices

ADVANCED FUNCTIONAL MATERIALS, Issue 7 2009
Hiroaki Yoshida
Abstract Various hydrogels, such as poly(, -glutamic acid) (, -PGA), gelatin (GT), alginic acid (Alg), and agarose (Aga), with 3D interconnected and oriented fibrous pores (OP gels) are prepared for 3D polymeric cellular scaffolds by using silica fiber cloth (SC) as template. After the preparation of these hydrogels with the SC templates, the latter are subsequently removed by washing with hydrofluoric acid solution. Scanning electron microscopy (SEM) clearly shows OP structures in the hydrogels. These various types of OP gels are successfully prepared in this way, independently of the crosslinking mechanism, such as chemical (, -PGA or GT), coordinate-bonded (Alg), or hydrogen-bonded (Aga) crosslinks. SEM, confocal laser scanning microscopy, and histological evaluations clearly demonstrate that mouse L929 fibroblast cells adhere to and extend along these OP structures on/in , -PGA hydrogels during 3D cell culture. The L929 cells that adhere on/in the oriented hydrogel are viable and proliferative. Furthermore, 3D engineered tissues, composed of the oriented cells and extracellular matrices (ECM) produced by the cells, are constructed in vitro by subsequent decomposition of the hydrogel with cysteine after 14 days of cell culture. This novel technology to fabricate 3D-engineered tissues, consisting of oriented cells and ECM, will be useful for tissue engineering. [source]

PDGF stimulates the massive expansion of glial progenitors in the neonatal forebrain

GLIA, Issue 16 2009
M. C. Assanah
Abstract Platelet-derived growth factor (PDGF) plays a major role in regulating migration, proliferation, and differentiation of glial progenitors during normal brain development and in the abnormal proliferation and dispersion that drives the formation of malignant gliomas. To further explore the relationship between PDGF's effects on normal glial progenitors and its role in the formation of gliomas, we infected progenitor cells in the subventricular zone (SVZ) of the lateral ventricle of neonatal rat pups with a retrovirus that expresses PDGF and green fluorescent protein (GFP). At 3 days post-injection (dpi), a proliferation of PDGFR,+ progenitors was seen in the SVZ and white matter around the injection site and by 10 dpi the animals had large diffusely infiltrating tumors that resembled glioblastomas. The tumors contained a massive proliferation of both infected and uninfected PDGFR,+ progenitors, suggesting that PDGF was driving tumor formation via both autocrine and paracrine signaling. Rats co-injected with two retroviruses (one that expresses PDGF-IRES-DSRED and one that expresses only GFP) formed tumors that contained a mixture of DSRED+ cells (PDGF producers) and GFP+ cells (recruited progenitors). Time-lapse microscopy of slice cultures confirmed that both DSRED+ and GFP+ cells were highly migratory and proliferative. Furthermore, adding exogenous PDGF to slice cultures generated from nontumor-bearing brains (injected with control GFP retrovirus only) stimulated the migration and proliferation of GFP+ progenitors. These findings reveal the inherent growth factor responsiveness and tumorigenic potential of PDGFR,+ progenitors and highlight the importance of paracrine signaling in stimulating glioma growth and infiltration. © 2009 Wiley-Liss, Inc. [source]

The Versatility of Helicobacter pylori CagA Effector Protein Functions: The Master Key Hypothesis

HELICOBACTER, Issue 3 2010
Steffen Backert
Abstract Several bacterial pathogens inject virulence proteins into host target cells that are substrates of eukaryotic tyrosine kinases. One of the key examples is the Helicobacter pylori CagA effector protein which is translocated by a type-IV secretion system. Injected CagA becomes tyrosine-phosphorylated on EPIYA sequence motifs by Src and Abl family kinases. CagA then binds to and activates/inactivates multiple signaling proteins in a phosphorylation-dependent and phosphorylation-independent manner. A recent proteomic screen systematically identified eukaryotic binding partners of the EPIYA phosphorylation sites of CagA and similar sites in other bacterial effectors by high-resolution mass spectrometry. Individual phosphorylation sites recruited a surprisingly high number of interaction partners suggesting that each phosphorylation site can interfere with many downstream pathways. We now count 20 reported cellular binding partners of CagA, which represents the highest quantitiy among all yet known virulence-associated effector proteins in the microbial world. This complexity generates a highly remarkable and puzzling scenario. In addition, the first crystal structure of CagA provided us with new information on the function of this important virulence determinant. Here we review the recent advances in characterizing the multiple binding signaling activities of CagA. Injected CagA can act as a ,master key' that evolved the ability to highjack multiple host cell signalling cascades, which include the induction of membrane dynamics, actin-cytoskeletal rearrangements and the disruption of cell-to-cell junctions as well as proliferative, pro-inflammatory and anti-apoptotic nuclear responses. The discovery that different pathogens use this common strategy to subvert host cell functions suggests that more examples will emerge soon. [source]

Pathogenesis of Helicobacter pylori Infection

HELICOBACTER, Issue 2008
Javier Torres
Abstract The clinical outcome of Helicobacter pylori infection is determined by a complex scenario of interactions between the bacterium and the host. The main bacterial factors associated with colonization and pathogenicity comprise outer membrane proteins including BabA, SabA, OipA, AlpA/B, as well as the virulence factors CagA in the cag pathogenicity island (cagPAI) and the vacuolating cytotoxin VacA. The multitude of these proteins and allelic variation makes it extremely difficult to test the contribution of each individual factor. Much effort has been put into identifying the mechanism associated with H. pylori -associated carcinogenesis. Interaction between bacterial factors such as CagA and host signal transduction pathways seems to be critical for mediating the induction of membrane dynamics, actin-cytoskeletal rearrangements and the disruption of cell-to-cell junctions as well as proliferative, pro-inflammatory and antiapoptotic nuclear responses. An animal model using the Mongolian gerbil is a useful system to study the gastric pathology of H. pylori infection. [source]

Quantitative determination of the diagnostic accuracy of the synovitis score and its components

HISTOPATHOLOGY, Issue 3 2010
Elisabeth Slansky
Slansky E, Li J, Häupl T, Morawietz L, Krenn V & Pessler F (2010) Histopathology,57, 436,443 Quantitative determination of the diagnostic accuracy of the synovitis score and its components Aims:, To assess the diagnostic accuracy of a three-component synovitis score and to determine the relative contribution of each of its components to its overall discriminatory power. Methods and results:, The synovitis score was determined in 666 synovial specimens: normal synovium, n = 33; post-traumatic arthropathy (PtA), n = 29; osteoarthritis (OA), n = 221; psoriatic arthritis (PsA), n = 42; and rheumatoid arthritis (RA), n = 341. The discriminatory abilities of the score and its components were quantified with binary and multicategory receiver operating characteristic (ROC) analysis. The score differentiated all arthropathies accurately from normal tissue (area under the ROC curve, AUC: 0.87,0.98) and RA from OA or PtA (AUC: 0.85 for both), but could not distinguish well within pairs of inflammatory or degenerative arthropathies. AUCs of the intimal hyperplasia and stromal cellularity components correlated with the AUCs of the complete score markedly more strongly (r = 0.94 and 0.91, respectively) than the inflammatory infiltration component (r = 0.60). Multicategory ROC analysis ranked the score several-fold higher than any of its components, and the components in the order stromal cellularity>intimal hyperplasia>infiltration. Conclusion:, Combining three distinct histological parameters into a three-component score produces greatly increased overall diagnostic power. The discriminatory ability of the score stems more from measuring proliferative than infiltrative aspects of synovitis. [source]

Role of a fetal defence mechanism against oxidative stress in the aetiology of preeclampsia

HISTOPATHOLOGY, Issue 1 2009
Christoph Jan Wruck
Aims:, Increasing evidence suggests that oxidative stress may play a key role in the aetiology of preeclampsia (PE). The aim of this study was to elucidate the placental defence mechanisms employed against oxidative stress and, in particular, the specific role of nuclear factor erythroid 2-related factor 2 (Nrf2). Methods and results:, Expression of Nrf2 in third-trimester placental tissue was compared in preeclamptic and normal gestation-matched controls. PE was associated with increased Nrf2 activity within cytotrophoblastic nuclei. Nrf2 expression was restricted to proliferative and early post-proliferative cytotrophoblast only. Syncytiotrophoblast was immunonegative for Nrf2 in both controls and preeclamptic placentas. Conclusions:, Nrf2 is exclusively active within cytotrophoblast, strongly suggesting that these cells are the origin of Nrf2-dependent gene products. Syncytiotrophoblast is transcriptionally inactive; therefore in times of oxidative stress essential cytoprotective enzymes must be derived from the cytotrophoblast. Excessive cytotrophoblastic turnover causes disproportionate release of toxic placental factors, manifesting as PE and endangering maternal health. Increased cytotrophoblastic proliferation/fusion could thus be interpreted as a fetal defence mechanism, initiated in response to the requirements of vulnerable syncytiotrophoblast. We therefore propose a direct relationship between fetal defence against oxidative stress and consequent placental toxicity as part of the aetiology of this complex maternal disease. [source]

Inflammatory bowel disease-associated gene expression in intestinal epithelial cells by differential cDNA screening and mRNA display

INFLAMMATORY BOWEL DISEASES, Issue 5 2003
Kouhei Fukushima M.D., Ph.D.
Abstract Intestinal epithelial cells are actively involved in the pathogenesis of inflammatory bowel disease resulting in an altered functional phenotype. The modulation of epithelial gene expression may occur as a consequence of proliferative, metabolic, immune, inflammatory, or genetic abnormalities. Differential screening of epithelial-cell-derived cDNA libraries (from control, ulcerative colitis, and Crohn's disease epithelial cells) and differential display of mRNA were used for investigation of disease-associated gene expression and modulation. Intestinal epithelial gene expression was successfully analyzed by both approaches. Using differential screening with clones encoding mitochondrial genes, quantitative overexpression was observed in both ulcerative colitis and Crohn's disease, while a unique expression of small RNA was noticed in Crohn's disease cells using Alu-homologous clones. Differential display demonstrated that several genes were differentially displayed among control, ulcerative colitis, and Crohn's disease epithelial cells. This was confirmed by immunohistochemical staining of pleckstrin, desmoglein 2 and voltage-dependent anion channel in control and inflammatory bowel disease mucosal samples. In summary, several inflammatory bowel disease-related associations were found. Since both differential screening and display have advantages and limitations, the combination of both techniques can generate complementary information, facilitate search for novel genes, and potentially identify genes uniquely associated with inflammatory bowel disease. [source]

Lef-1 isoforms regulate different target genes and reduce cellular adhesion

INTERNATIONAL JOURNAL OF CANCER, Issue 5 2010
Sarah Jesse
Abstract The lymphoid enhancer factor 1 (Lef-1) belongs to the nuclear transducers of canonical Wnt-signalling in embryogenesis and cancer. Lef-1 acts, in cooperation with ,-catenin, as a context-dependent transcriptional activator or repressor, thereby influencing multiple cellular functions such as proliferation, differentiation and migration. Here we report that an increased Lef-1 expression in human pancreatic cancer correlates with advanced tumour stages. In pancreatic tumours, two different transcripts of Lef-1 have been detected in various stages, as demonstrated by RT-PCR analysis. One transcript was identified as the full length Lef-1 (Lef-1 FL), whereas the second, shorter transcript lacked exon VI (Lef-1 ,exon VI) compared to the published sequence. Comparative analysis of these two Lef-1 variants revealed that they exhibit different cellular effects after transient expression in pancreatic carcinoma cells. Forced expression of Lef-1 ,exon VI inhibited E-cadherin expression in a ,-catenin-independent way. Increased amounts of Lef-1 ,exon VI resulted in reduced cellular aggregation and increased cell migration. Expression of Lef-1 FL, but not the newly identified Lef-1 ,exon VI, induced the expression of the cell cycle regulating proteins c-myc and cyclin D1 in cooperation with ,-catenin and it enhanced cell proliferation. Our findings indicate that expression of alternatively spliced Lef-1 isoforms is involved in the determination of proliferative or migratory characteristics of pancreatic carcinoma cells. [source]

BRCA1 modulates malignant cell behavior, the expression of survivin and chemosensitivity in human breast cancer cells,

INTERNATIONAL JOURNAL OF CANCER, Issue 12 2009
Moltira Promkan
Abstract BRCA1 is a multifunctional tumor-suppressive protein. Many functional aspects of BRCA1 are not fully understood. We used a shRNA approach to probe the function of BRCA1 in human breast cancer cells. Knocking down BRCA1 expression by shRNA in the wild-type BRCA1 human breast cancer MCF-7 and MDA-MB-231 cells resulted in an increase in cell proliferation, anchorage-independent growth, cell migration, invasion and a loss of p21/Waf1 and p27Kip1 expression. In BRCA1 knocked-down cells, the expression of survivin was significantly up regulated with a concurrent decrease in cellular sensitivity to paclitaxel. We also found that cells harboring endogenous mutant or defective BRCA1 (MDA-MB-436 and HCC1937) were highly proliferative and expressed a relatively low level of p21/Waf1 and p27Kip1 by comparison to wild-type BRCA1 cells. Cells harboring mutated BRCA1 also expressed a high level of survivin and were relatively resistant to paclitaxel by comparison to wild-type cells. Increase resistance to paclitaxel was due to an increase in the expression of survivin in both the BRCA1 knocked-down and mutant BRCA1 cells because knocking down survivin expression by siRNA restored sensitivity to paclitaxel. We conclude that BRCA1 down-modulates the malignant behavior of breast cancer cells, promotes the expression of p21/Waf1, p27Kip1 and inhibits the expression of survivin. Moreover, loss of BRCA1 expression or function leads to an increase in survivin expression and a reduction in chemosensitivity to paclitaxel. © 2009 UICC [source]

HPV related VIN: Highly proliferative and diminished responsiveness to extracellular signals

INTERNATIONAL JOURNAL OF CANCER, Issue 4 2007
Lindy A.M. Santegoets
Abstract Vulvar intraepithelial neoplasia (VIN) is a premalignant disorder caused by human papillomaviruses. Basic knowledge about the molecular pathogenesis of VIN is sparse. Therefore, we have analyzed the gene expression profile of 9 VIN samples in comparison to 10 control samples by using genome wide Affymetrix Human U133A plus2 GeneChips. Results were validated by quantitative real-time RT-PCR analysis and immunostaining of a few representative genes (TACSTD1, CCNE2, AR and ESR1). Significance analysis of microarrays (SAM) showed that 1,497 genes were differentially expressed in VIN compared to controls. By analyzing the biological processes affected by the observed differences, we found that VIN appears to be a highly proliferative disease; many cyclins (CCNA, CCNB and CCNE) and almost all prereplication complex proteins are upregulated. Thereby, VIN does not seem to depend for its proliferation on paracrine or endocrine signals. Many receptors (for example ESR1 and AR) and ligands are downregulated. Furthermore, although VIN is not an invasive disease, the inhibition of expression of a marked number of cell,cell adhesion molecules seems to indicate development towards invasion. Upon reviewing apoptosis and angiogenesis, it was observed that these processes have not become significantly disregulated in VIN. In conclusion: although VIN is still a premalignant disease, it already displays several hallmarks of cancer. © 2007 Wiley-Liss, Inc. [source]

Magnitude and polarization of P53-specific T-helper immunity in connection to leukocyte infiltration of colorectal tumors

INTERNATIONAL JOURNAL OF CANCER, Issue 3 2003
Sjoerd H. van der Burg
Abstract The tumor antigen p53 is mutated frequently and overexpressed in colorectal cancer. As a result, patients with this type of cancer commonly display p53-specific T-helper (Th) immunity. Examination of the cytokines produced by these Th-cells showed that a majority of the proliferative p53-specific T cell cultures produced none of the key cytokines (IFN,, TNF,, IL-4, IL-5 or IL-10), indicating that these p53-specific Th-responses are not polarized. In patients who exhibited p53-specific reactivity against multiple p53-epitopes, non-polarized responses could be found side by side with polarized Th-responses that produced INF, or other cytokines such as IL-10. Patients who exhibited p53-specific IFN,-producing Th cell-immunity before surgical excision of the tumor displayed higher numbers of tumor infiltrating intraepithelial leukocytes (p = 0.04) than patients lacking such responses, suggesting that the systemic presence of p53-specific Th-cells positively affects local tumor-immunity. Our data concerning the polarization-state of p53-specific Th immunity in colorectal cancer patients support the use of vaccine formulations that induce strong Th1-polarized p53-specific immunity to ensure proper (re-)programming of the anti-tumor response. © 2003 Wiley-Liss, Inc. [source]

Original semiologic standardized evaluation of stratum corneum hydration by Diagnoskin® stripping sample

INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 3 2004
P. Gasser
Synopsis In a normal and healthy skin, the regular elimination of the superficial corneocytes, called desquamation, is a fundamental physiologic process intended to protect the barrier function of the skin. This invisible loss of corneocytes, individually or in small groups, is incessantly compensated by the divisions of the proliferative layer and the upward cellular maturation in order to maintain the harmonious renewal of the epidermis and the integrity of the stratum corneum. The harmony of this desquamation process is intimately conditioned by a sufficient hydration of the stratum corneum: (i) an abnormal desquamation leads to a disruption of the water barrier function and consequently to a dehydration tendency of the stratum corneum, and (ii) a cutaneous dryness (whatever the cause) is able to disturb the desquamation process. Protecting the water content of the stratum corneum has always been a major preoccupation of the cosmetic industry scientists. Consequently, the moisturizing properties of a cosmetic product are objectively measured by various explorations directly targeted on the hydration (corneometry) and on the level of the water barrier function (transepidermal water loss (TEWL) measurements), which depends directly on the skin hydration state. This intimate linkage of the desquamation process and the water content of the stratum corneum enable us to suggest an indirect assessment of the hydration from a direct study of the desquamation by examining a skin-stripping sample (D-Squames®) by an optical microscope (linked to a computer). We will describe this already known technique and mainly its new and unpublished semiologic exploitation, named Diagnoskin®, whose advantages are its simplicity and its reproducibility particularly interesting in the case of sequential appraisal of dermatologic or cosmetic treatments. Résumé Sur une peau normale et saine, l'élimination régulière des cornéocytes superficiels, appelée desquamation, est un processus physiologique fondamental destinéà préserver la fonction barrière de la peau. La perte invisible des cornéocytes, individuellement ou par petits paquets cellulaires, est sans cesse compensée par les divisions de la couche germinative et la maturation cellulaire ascensionnelle afin de maintenir le renouvellement harmonieux de l'épiderme et l'intégrité du stratum corneum. L'harmonie de ce processus de desquamation est intimement conditionnée par une hydratation suffisante du stratum corneum: une desquamation anormale aboutit à une perturbation de la fonction barrière et donc à une tendance à la déshydratation du stratum corneum, Une sècheresse cutanée (quelle qu'en soit la cause) va perturber la desquamation. Préserver la teneur en eau du stratum corneum est depuis toujours une préoccupation majeure pour le scientifique de l'industrie cosmétique. L'appréciation objective du caractère hydratant d'une crème cosmétique est d'ailleurs mesuré par diverses explorations directement ciblées sur l'hydratation (cornéométrie) et sur l'état de la fonction barrière (Perte Insensible en Eau ,PIE) qui dépend directement de l'état d'hydratation de la peau. Cette liaison intime du niveau d'hydratation du stratum corneum et du phénomène de desquamation nous a fait proposer une évaluation indirecte de l'hydratation à l'aide d'une étude directe de la desquamation par observation au microscope (reliéà un ordinateur) des prélèvements par stripping des cornéocytes superficiels (D-Squames®). Nous décrirons cette technique déjà connue et surtout son exploitation sémiologique nouvelle et inédite, appelée Diagnoskin® dont les avantages sont sa simplicité et son caractère reproductible particulièrement intéressants pour l'évaluation séquentielle de traitements dermatologiques ou cosmétiques. [source]

Expression of minichromosome maintenance 5 protein in proliferative and malignant skin diseases

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 11 2007
Houjun Liu
Background, The entire minichromosome maintenance (MCM) family (MCM2,7) play roles in the initiation and elongation of DNA replication. Many studies have demonstrated that MCM proteins may be better indicators of a wide variety of proliferative or cancer cells in malignant tissues. Objectives, To characterize the pattern and frequency of MCM5 expression in proliferative and malignant skin diseases in comparison with those of proliferating cell nuclear antigen (PCNA). Methods, Twelve normal skin specimens, 12 specimens of psoriasis, 21 specimens of bowenoid papulosis (BP), 16 specimens of Bowen's disease (BD), 38 specimens of skin squamous cell carcinoma (SCC), and 11 specimens of basal cell carcinoma (BCC) were subjected to immunohistochemical staining for MCM5 and PCNA. Results, MCM5 protein was expressed in the lower layers of epidermis in psoriasis, while MCM5 protein were present throughout the tumor cells in BP, BD, and moderately/poorly differentiated SCC. MCM5 protein was preferentially expressed in the periphery of well-differentiated SCC or bigger nests of BCC, although some small nests of BCC seemingly showed diffuse staining patterns. The percentages of MCM5-positive cells were 15.7% in normal skin, 21.8% in psoriasis, 75.9% in BP, 83.8% in BD, 63.5% in well-differentiated SCC, 77.5% in moderately differentiated SCC, 79.8% in poorly differentiated SCC, and 21.2% in BCC in average. Well-differentiated SCC showed a significantly lower percentage of positive cells than did moderately differentiated SCC or poorly differentiated SCC. MCM5 staining basically show a similar staining pattern to that of PCNA, but more cells tended to be stained with MCM5 than with PCNA. Conclusions, Our results demonstrate pattern and frequency of MCM5 expression in various skin diseases and suggest that MCM5 may be a useful marker to detect cell proliferation in skin tissue sections. [source]

The role of melatonin in immuno-enhancement: potential application in cancer

INTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 2 2006
Sandra C. Miller
Summary Melatonin, a neurohormone produced mainly by the pineal gland, is a modulator of haemopoiesis and of immune cell production and function, both in vivo and in vitro. Physiologically, melatonin is associated with T-helper 1 (Th1) cytokines, and its administration favours Th1 priming. In both normal and leukaemic mice, melatonin administration results in quantitative and functional enhancement of natural killer (NK) cells, whose role is to mediate defenses against virus-infected and cancer cells. Melatonin appears to regulate cell dynamics, including the proliferative and maturational stages of virtually all haemopoietic and immune cells lineages involved in host defense , not only NK cells but also T and B lymphocytes, granulocytes and monocytes , in both bone marrow and tissues. In particular, melatonin is a powerful antiapoptotic signal promoting the survival of normal granulocytes and B lymphocytes. In mice bearing mid-stage leukaemia, daily administration of melatonin results in a survival index of 30,40% vs. 0% in untreated mice. Thus, melatonin seems to have a fundamental role as a system regulator in haemopoiesis and immuno-enhancement, appears to be closely involved in several fundamental aspects of host defense and has the potential to be useful as an adjuvant tumour immunotherapeutic agent. [source]

The treatment of leprosy in 19th-century London: a case study from St Marylebone cemetery

INTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 3 2009
D. WalkerArticle first published online: 19 MAY 200
Abstract A young adult male, context [825], exhibiting a suite of proliferative and erosive skeletal changes, was excavated from the old burial ground of St Marylebone, London, in 2005 by the Museum of London Archaeology Service (MoLAS). Although pathognomonic rhinomaxillary changes were absent, a number of lesions were of a type previously recorded in individuals suffering from lepromatous leprosy, including resorption of the alveolar process of the maxillae and the digits of the right hand, osteomyelitis in the left ulna and collapse of the left ankle. Whilst this infectious disease was widespread in medieval Britain, it had declined by the 19th century, and has been identified in only one other post-medieval archaeological context. The right leg of [825] had been surgically amputated. This form of intervention was a recognised treatment for the complications of the disease, where neuropathic damage of limbs led to life-threatening infection. The healing of the amputation demonstrates the success of the operation, and the skill of the surgeon. Although the identity of the affected individual is unknown, burial within St Marylebone cemetery implies a level of status not frequently associated with leprosy sufferers in the past. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Resistance to UV-induced apoptosis in human keratinocytes during accelerated senescence is associated with functional inactivation of p53

JOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2004
V. Chaturvedi
Compared to proliferating keratinocytes (KCs), growth-arrested KCs are relatively resistant to UV-light induced apoptosis. When KCs undergo confluency, or following exposure to anti-proliferative agents such as IFN-, plus a phorbol ester,12- O -tetradecanoylyphorbol-13-acetate (TPA), they convert from a proliferative to a nonproliferative state resembling senescence. Since p53 regulates UV-induced apoptosis of KCs, this report further characterizes p53 half-life, post-translational modifications, and transcriptional activity using cultured human KCs and living epidermal equivalents. The half-life of p53 in KCs was longer than fibroblasts (greater than approximately 3 h vs. 30 min). Exposure of proliferating KCs to UV-light induces post-translational modifications of p53 including acetylation of lysine-382 residues. By contrast, KCs undergoing irreversible growth arrest following confluency, or exposure to IFN-, plus TPA, were resistant to UV-induced apoptosis, and failed to undergo the acetylation modification of p53. Exposure of KCs to IFN-, plus TPA reduced total cellular p53 levels and reduced the transcriptional activity of p53. Addition of Trichostatin A (TSA), an inhibitor of de-acetylation, increased acetylation of lysine-382 in confluent KCs, thereby enhancing susceptibility of confluent cultures to UV-induced apoptosis. Pre-treatment of epidermal equivalents with IFN-, plus TPA also blocked UV-light induced increase in p53 levels, and reduced apoptosis. In conclusion, these studies demonstrate that growth arrested KCs may resist UV-light induced apoptosis by inactivating the pro-apoptotic function of p53. J. Cell. Physiol. 198: 100,109, 2004. © 2003 Wiley-Liss, Inc. [source]

Partial restoration of T-cell function in aged mice by in vitro blockade of the PD-1/,PD-L1 pathway

AGING CELL, Issue 5 2010
Celine S. Lages
Summary Programmed cell death-1 (PD-1) is a newly characterized negative regulator of immune responses. The interaction of PD-1 with its ligands (PD-L1 and PD-L2) inhibits T-cell proliferation and cytokine production in young mice. Increased PD-1 expression has been described during chronic infections, inducing chronic activation of the immune system to control it. As aging is associated with chronic immune activation, PD-1 may contribute to age-associated T-cell dysfunction. Our data showed the following results in aged mice: (i) the number of PD-1-expressing T cells and the level of expression of PD-Ls was increased on dendritic cell subsets and T cells; (ii) PD-1+ T cells were exhausted effector memory T cells, as shown by their lower level of CD127, CD25 and CD28, as well as their limited proliferative and cytokine-producing capacity; (iii) the expression of PD-1 was up-regulated after T-cell receptor-mediated activation of CD8+ T cells, but not of CD4+ T cells; (iv) blockade of the PD-1/PD-L1 pathway moderately improved the cytokine production of T cells from old mice but did not restore their proliferation; and (v) blockade of the PD-1/PD-L1 pathway did not restore function of PD-1+ T cells; its effect appeared to be exclusively mediated by increased functionality of the PD-1, T cells. Our data thus suggest that blockade of the PD-1/PD-L1 is not likely to be efficient at restoring exhausted T-cell responses in aged hosts, although improving the responses of PD-1, T cells may prove to be a helpful strategy in enhancing primary responses. [source]