Neural Cell Adhesion Molecule Expression Research Articles

CD56 (Neural Cell Adhesion Molecule) Expression in Ovarian Carcinomas: Association With High-Grade and Advanced Stage But Not With Neuroendocrine Differentiation.

Neural cell adhesion molecule (CD56) has been proposed as a potential marker for neuroendocrine differentiation in carcinomas, together with synaptophysin and chromogranin A. However, CD56 immunoreactivity by itself can be found in a broad variety of tumors, including ovarian neoplasms. CD56 has recently been suggested as a potential target for antibody-based therapy. However, for ovarian carcinoma, there is only limited data available regarding the pattern of CD56 immunoreactivity, coexpression of neuroendocrine markers, and correlation with histological types and clinical parameters. In our study, we therefore evaluated CD56 staining by immunohistochemistry on a tissue micrroarray with 206 ovarian carcinomas, including 151 high-grade serous, 7 low-grade serous, 32 endometrioid, 11 clear cell, 5 mucinous, as well as 33 atypically proliferating serous tumors/serous borderline tumors. At least focal CD56 immunoreactivity was observed in 65% of carcinomas of all histological types. Moderate staining with at least 10% positive cells was found in 44 (28%) high-grade serous carcinomas (HGSOCs), 2 (29%) low-grade serous and 3(9%) endometrioid carcinomas. Strong immunoreactivity was limited to 10 (7%) HGSOCs. There was no correlation with the expression of chromogranin or synaptophysin. Serous borderline tumors showed only weak and focal staining in 11 (33%). Expression of CD56 overall was significantly associated with high-grade and advanced stage. In the subgroup of HGSOCs, CD56 expression was associated with reduced overall survival (median 30 vs. 47 months, P = 0.039, log rank, univariate analysis). CD56 (neural cell adhesion molecule) is frequently expressed in ovarian carcinomas and is significantly associated with HGSOC and advanced tumor stage. Due to its lack of correlation with neuroendocrine differentiation, CD56 expression is of limited diagnostic value, but may rather serve as a marker for tumor progression or as a potential therapeutic target.

Lithium treatment prior to radiation exposure of human neuroblastoma cells modifies outcome of cellular damage

Introduction: Radiation exposure to brain is known to cause cognitive deficits. Aim of the current study was to investigate whether lithium protects against radiation. It was further investigated whether this protective effect is associated with neuritogenesis and altered Neural Cell Adhesion Molecule (NCAM) expression. Materials and Methods: Human neuroblastoma cell line, SK-N-MC was exposed to gamma radiation alone and after 24 h pretreatment with lithium. Cells were scored for viability by MTT assay and checked for apoptotic changes by flow cytometry (FCM). Geimsa stained cells were scored for number of cells bearing neuritis and length of neuritis. Real time PCR was used to measure levels of NCAM transcript in the cells. Results: Radiation exposure of 5 Gray resulted in significant decrease in cell viability. Pretreatment with lithium rescued cells from radiation- induced toxicity as indicated by MTT assay and by FCM analysis. Morphological observations suggested radiation caused increase in neurite lengths and decrease in number of cells bearing neurites. This was reversed by lithium treatment. Several fold decrease in NCAM expression was observed post radiation exposure which was reversed by lithium pretreated cells. Conclusion: Lithium protects neuronal cells against radiation damage. The protective effect of lithium is associated with change in differentiation status of cells as indicated by neuritogenesis and with alteration in expression of NCAM, a molecule known to be associated with neurite formation.

Separate development of the maxilla and mandible is controlled by regional signaling of the maxillomandibular junction during avian development.

Syngnathia is a congenital craniofacial disorder characterized by bony or soft tissue fusion of upper and lower jaws. Previous studies suggested some causative signals, such as Foxc1 or Bmp4, cause the disruption of maxillomandibular identity, but their location and the interactive signals involved remain unexplored. We wanted to examine the embryonic origin of syngnathia based on the assumption that it may be located at the separation between the maxillary and mandibular processes. This region, known as the maxillomandibular junction (MMJ), is involved in segregation of cranial neural crest-derived mesenchyme into the presumptive upper and lower jaws. Here we investigated the role of Fgf, Bmp, and retinoid signaling during development of MMJ in chicken embryos. By changing the levels of these signals with bead implants, we induced syngnathia with microstomia on the treated side, which showed increased Barx1 and neural cell adhesion molecule (NCAM) expression. Redistribution of proliferating cells was also observed at the proximal region to maxillary and mandibular arch around MMJ. We propose that interactive molecular signaling by Fgfs, Bmps, and retinoids around MMJ is required for normal separation of the maxilla and mandible, as well as the proper positioning of beak commissure during early facial morphogenesis. Developmental Dynamics 246:28-40, 2017. © 2016 Wiley Periodicals, Inc.

Polysialylated Neural Cell Adhesion Molecule Protects Against Light-Induced Retinal Degeneration.

PurposeWe previously demonstrated that neural cell adhesion molecule (NCAM) plays an important role in supporting the survival of injured retinal ganglion cells. In the current study, we used light-induced retinal degeneration (LIRD) as a model to investigate whether NCAM plays a functional role in neuroprotection and whether NCAM influences p75NTR signaling in modulating retinal cell survival.MethodsRetinas from wild-type (WT) and NCAM deficient (−/−) mice were tested by electroretinogram before and after LIRD, and changes in the protein expressions of NCAM, polysialic acid (PSA)-NCAM, p75NTR, and active caspase 3 were measured by immunoblot from 0 to 4 days after light induction. The effects of NCAM and PSA-NCAM on p75NTR were examined by intraocular injections of the p75NTR function-blocking antibody and/or the removal of PSA with endoneuraminidase-N prior to LIRD.ResultsIn WT mice, low levels of active caspase 3 activation were detected on the first day, followed by increases up to 4 days after LIRD. Conversely, in NCAM−/− mice, higher cleaved caspase 3 levels along with rapid reductions in electroretinogram amplitudes were found earlier at day 1, followed by reduced levels by day 4. The removal of PSA prior to LIRD induced earlier onset of retinal cell death, an effect delayed by the coadministration of endoneuraminidase-N and the p75NTR function-blocking antibody antiserum.ConclusionsThese results indicate that NCAM protects WT retinas from LIRD; furthermore, the protective effect of NCAM is, at least in part, attributed to its effects on p75NTR.

Exenatide Alters Gene Expression of NCAM, ICAM, and VCAM in the Hippocampus of Type 2 Diabetic Model Mice.

BackgroundGlucagon-like peptide-1 (GLP-1), a potent and selective agonist for the GLP-1 receptor, ameliorates the symptoms of diabetes through stimulation of insulin secretion. Exenatide is a potent and selective agonist for the GLP-1 receptor. Cell adhesion molecules are members of the immunoglobulin superfamily and are involved in synaptic rearrangements in the mature brain.Material/MethodsThe present study demonstrated the effects of exenatide treatment (0.1 μg/kg, subcutaneously, twice daily for 2 weeks) on the gene expression levels of cell adhesion molecules, neural cell adhesion molecule (NCAM), intercellular cell adhesion molecule (ICAM), and vascular cell adhesion molecule (VCAM) in the brain tissue of diabetic BALB/c male mice by real-time quantitative polymerase chain reaction (PCR). Diabetes was induced by streptozotocin/nicotinamide (STZ-NA) injection to male mice.ResultsThe results of this study revealed that hippocampal gene expression of NCAM, ICAM, and VCAM were found to be up-regulated in STZ-NA-induced diabetic mice compared to those of controls. A significant decrease in the gene expression levels of NCAM, ICAM, and VCAM were determined after 2 weeks of exenatide administration.ConclusionsCell adhesion molecules may be involved in the molecular mechanism of diabetes. Exenatide has a strong beneficial action in managing diabetes induced by STZ/NA by altering gene expression of NCAM, ICAM, and VCAM.

Neurochemical Phenotype of Reelin Immunoreactive Cells in the Piriform Cortex Layer II.

Reelin, a glycoprotein expressed by Cajal-Retzius neurons throughout the marginal layer of developing neocortex, has been extensively shown to play an important role during brain development, guiding neuronal migration and detachment from radial glia. During the adult life, however, many studies have associated Reelin expression to enhanced neuronal plasticity. Although its mechanism of action in the adult brain remains mostly unknown, Reelin is expressed mainly by a subset of mature interneurons. Here, we confirm the described phenotype of this subpopulation in the adult neocortex. We show that these mature interneurons, although being in close proximity, lack polysialylated neural cell adhesion molecule (PSA-NCAM) expression, a molecule expressed by a subpopulation of mature interneurons, related to brain development and involved in neuronal plasticity of the adult brain as well. However, in the layer II of Piriform cortex there is a high density of cells expressing Reelin whose neurochemical phenotype and connectivity has not been described before. Interestingly, in close proximity to these Reelin expressing cells there is a numerous subpopulation of immature neurons expressing PSA-NCAM and doublecortin (DCX) in this layer of the Piriform cortex. Here, we show that Reelin cells express the neuronal marker Neuronal Nuclei (NeuN), but however the majority of neurons lack markers of mature excitatory or inhibitory neurons. A detail analysis of its morphology indicates these that some of these cells might correspond to semilunar neurons. Interestingly, we found that the majority of these cells express T-box brain 1 (TBR-1) a transcription factor found not only in post-mitotic neurons that differentiate to glutamatergic excitatory neurons but also in Cajal-Retzius cells. We suggest that the function of these Reelin expressing cells might be similar to that of the Cajal-Retzius cells during development, having a role in the maintenance of the immature phenotype of the PSA-NCAM/DCX neurons through its receptors apolipoprotein E receptor 2 (ApoER2) and very low density lipoprotein receptor (VLDLR) in the Piriform cortex layer II during adulthood.

The effects of morphine treatment on the NCAM and its signaling in the MLDS of rats

Prolonged exposure to opiates induces a constellation of neuroadaptations, especially in the mesolimbic dopamine system (MLDS), which leads to alteration in the function of motivational circuitry. The neural cell adhesion molecule (NCAM) mediates cell–cell interactions and plays an important role in processes associated with neural plasticity. Moreover, it has been shown that NCAM were related to risk of alcoholism in human populations. Here, coimmunoprecipitation and western blotting were used to investigate whether morphine treatment induced alteration of the expression of NCAM or its signaling level in MLDS. The rats receiving escalating dose of morphine treatment were divided into three groups: morphine 1d, 3d and 5d group, which were injected subcutaneously with morphine hydrochloride for 1 day, 3 days and 5 days, respectively. Twelve hours after the last injection, animals were sacrificed and the tissues of ventral tegmental area (VTA), prefrontal cortex (PFC) and nucleus accumbens (NAc) were punched out to examine the expression of NCAM or its signaling level. The results showed that morphine treatment had no significant effect on the expression of NCAM, but downregulated the phosphorylation of NCAM-associated focal adhesion kinase (FAK) in the VTA and PFC of rats. In the NAc of rats, however, the expression of NCAM and its signaling were not altered significantly by morphine treatment. These results indicated that the downregulation of NCAM signaling in the VTA and PFC might be involved in the formation of morphine addiction.

Pre-degenerated peripheral nerves co-cultured with bone marrow-derived cells: a new technique for harvesting high-purity Schwann cells.

Schwann cells play an important role in the peripheral nervous system, especially in nerve repair following injury, so artificial nerve regeneration requires an effective technique for obtaining purified Schwann cells. In vivo and in vitro pre-degeneration of peripheral nerves have been shown to obtain high-purity Schwann cells. We believed that in vitro pre-degeneration was simple and controllable, and available for the clinic. Thus, we co-cultured the crushed sciatic nerves with bone marrow-derived cells in vitro. Results demonstrated that, 3 hours after injury, a large number of mononuclear cells moved to the crushed nerves and a large number of bone marrow-derived cells infiltrated the nerve segments. These changes promoted the degradation of the nerve segments, and the dedifferentiation and proliferation of Schwann cells. Neural cell adhesion molecule and glial fibrillary acidic protein expression were detected in the crushed nerves. Schwann cell yield was 9.08 ± 2.01 × 104/mg. The purity of primary cultured Schwann cells was 88.4 ± 5.79%. These indicate a successful new method for obtaining Schwann cells of high purity and yield from adult crushed sciatic nerve using bone marrow-derived cells.

CD56 and RUNX1 isoforms in AML prognosis and their therapeutic potential

Neural cell adhesion molecule (NCAM/CD56) expression in acute myeloid leukemia (AML) has been associated with extramedullary leukemia, multidrug resistance, shorter remission and survival. Recently, Bloomfield et al. published a succinct review of issues surrounding the AML prognostication and current therapeutics. However, we want to reiterate the prognostic value and therapeutic potential of CD56 that is frequently expressed in AML as was also reported by their own group earlier. In addition, novel RUNX1 isoforms contribute in controlling CD56 expression in AML cells. Anti-CD56 antibody therapy deserves exploration as an arsenal against AML patients expressing CD56. Relevantly, targeting RNA splicing machinery or RUNX1 isoform-specific siRNA may also become part of future therapeutic strategies for AML with CD56 overexpression.

MiR-30a-5p is induced by Wnt/β-catenin pathway and promotes glioma cell invasion by repressing NCAM

Wnt/β-catenin signaling pathway is frequently dysregulated in human tumors and plays a critical role in tumorigenesis; however, the roles of microRNAs in mediating Wnt/β-catenin pathway are not well understood. Herein, we show that miR-30a-5p is activated by Wnt/β-catenin pathway through direct binding of β-catenin/TCF4 to two sites in the promoter region of miR-30a-5p. We also found that miR-30a-5p represses neural cell adhesion molecule (NCAM) expression by directly targeting two sites in the 3′ untranslated region (3′-UTR) of NCAM mRNA. Moreover, Wnt/β-catenin pathway represses NCAM expression in glioma cells, which depends on miR-30a-5p. Finally, we found that miR-30a-5p promotes glioma cell growth invasion by repressing NCAM. Our findings demonstrate a novel Wnt/β-catenin–miR-30a-5p–NCAM regulatory axis which plays important roles in controlling glioma cell invasion and tumorigenesis.

Withania somnifera Suppresses Tumor Growth of Intracranial Allograft of Glioma Cells.

Gliomas are the most frequent type of primary brain tumor in adults. Their highly proliferative nature, complex cellular composition, and ability to escape therapies have confronted investigators for years, hindering the advancement toward an effective treatment. Agents that are safe and can be administered as dietary supplements have always remained priority to be most feasible for cancer therapy. Withania somnifera (ashwagandha) is an essential ingredient of Ayurvedic preparations and is known to eliminate cancer cells derived from a variety of peripheral tissues. Although our previous studies have addressed the in vitro anti-proliferative and differentiation-inducing properties of ashwagandha on neuronal cell lines, in vivo studies validating the same are lacking. While exploring the mechanism of its action in vitro, we observed that the ashwagandha water extract (ASH-WEX) induced the G2/M phase blockade and caused the activation of multiple pro-apoptotic pathways, leading to suppression of cyclin D1, bcl-xl, and p-Akt, and reduced the expression of polysialylated form of neural cell adhesion molecule (PSA-NCAM) as well as the activity of matrix metalloproteinases. ASH-WEX reduced the intracranial tumor volumes in vivo and suppressed the tumor-promoting proteins p-nuclear factor kappa B (NF-κB), p-Akt, vascular endothelial growth factor (VEGF), heat shock protein 70 (HSP70), PSA-NCAM, and cyclin D1 in the rat model of orthotopic glioma allograft. Reduction in glial fibrillary acidic protein (GFAP) and upregulation of mortalin and neural cell adhesion molecule (NCAM) expression specifically in tumor-bearing tissue further indicated the anti-glioma efficacy of ASH-WEX in vivo. Combining this enhanced understanding of the molecular mechanisms of ASH-WEX in glioma with in vivo model system offers new opportunities to develop therapeutic strategy for safe, specific, and effective formulations for treating brain tumors.

Twist predicts poor outcome of patients with astrocytic glioma

Aims and methodsEpithelial-mesenchymal transition (EMT) has previously been linked to glioma invasion and progression. To determine whether EMT regulators, Twist and Zeb1, had clinical significance in astrocytic gliomas, the association...

Increased prolyl endopeptidase induces alterations in the expression of neural cell adhesion molecule and its polysialylation in SH-SY5Y neuroblastoma cells in vitro

Development of the nervous system and its structural remodelling in the adult relies on molecules mediating the structural plasticity of neurons, e specially those involved in cell adhesion, cytoskeletal dynamics or synapse formation. Neural cell adhesion molecule (NCAM) is a membrane-associated glycoprotein that can be modified by glycosylation with polysialic acid (PSA), attenuating NCAM-mediated cell interactions, thereby promoting structural plasticity [1]. It has been demonstrated that in conditions of neuroinflammation, NCAM can be cleaved extracellularly by metalloproteinases and other proteolytical enzymes. Prolyl endopeptidase (PREP) is a cytosolic serine protease, and alterations in PREP expression and activity have been associated with neuronal death and neuroinflammation [2]. Since the precise mechanisms and possible partners of PREP in neuroinflammation remain unclear, the aim of this study was to determine whether increased secretion and activation of PREP could impair NCAM expression and its polysialylation. SH-SY5H cell line overexpressing (o/e) PREP was used as an in vitro model for increased PREP expression and extracellular release. When measuring expression levels of NCAM and PSA-NCAM we found remarkable loss in PSA-NCAM and disrupted expression patterns of NCAM compared to wild-type cells. As matrix metalloproteinase 9 (MMP-9) has been indicated in processes regulating shedding of PSA-NCAM, MMP-9 expression level was measured. An increase in the level of the active form of MMP-9 was found, which was counteracted by a specific inhibitor of PREP, KYP-2047. As demonstrated, PREP might have an important role in processes involved in NCAM degradation and polysialylation, thereby inducing progression of pathologies associated with altered neuroplasticity.

Distinct patterns of outcome valuation and amygdala-prefrontal cortex synaptic remodeling in adolescence and adulthood.

Adolescent behavior is typified by increased risk-taking, reward- and novelty-seeking, as well as an augmented need for social and environmental stimulation. This behavioral phenotype may result from alterations in outcome valuation or reward learning. In the present set of experiments, we directly compared adult and adolescent animals on tasks measuring both of these processes. Additionally, we examined developmental differences in dopamine D1-like receptor (D1R), dopamine D2-like receptor (D2R), and polysialylated neural cell adhesion molecule (PSA-NCAM) expression in animals that were trained on an effortful reward valuation task, given that these proteins play an important role in the functional development of the amygdala-prefrontocortical (PFC) circuit and mesocorticolimbic dopamine system. We found that adolescent animals were not different from adults in appetitive associative learning, but exhibited distinct pattern of responses to differences in outcome values, which was paralleled by an enhanced motivation to invest effort to obtain larger rewards. There were no differences in D2 receptor expression, but D1 receptor expression was significantly reduced in the striatum of animals that had experiences with reward learning during adolescence compared to animals that went through the same experiences in adulthood. We observed increased levels of PSA-NCAM expression in both PFC and amygdala of late adolescents compared to adults that were previously trained on an effortful reward valuation task. PSA-NCAM levels in PFC were strongly and positively associated with high effort/reward (HER) choices in adolescents, but not in adult animals. Increased levels of PSA-NCAM expression in adolescents may index increased structural plasticity and represent a neural correlate of a reward sensitive endophenotype.

Solitary and Multiple Meningiomas: an Immunohistochemical Comparison

Summary Introduction. Meningiomas are common primary tumors of brain meninges. These neoplasms develop from arachnoid cap cells and are multiple in 1 - 10% cases. Occasionally, significantly higher multiplicity rates have been reported, at least partially due to the increased application of computed tomography and magnetic resonance imaging in the diagnostics of intracranial pathologies. Meningiomas generally express progesterone receptors, but only few studies have focused on sex hormone receptor differences between solitary and multiple meningiomas. Similarly, there is limited information on cell proliferation and adhesion factors in solitary and multiple meningiomas. Aim of the study. Was to evaluate the immunohistochemical differences in sex hormone receptor expression, cell proliferation and adhesion within solitary and multiple meningiomas. Material and methods. In a retrospective study, 11 consecutive multiple meningiomas and 20 grade-matched solitary meningiomas were assessed by immunohistochemistry (IHC) to detect estrogen receptors (ER), progesterone receptors (PR), Ki-67 and neural cell adhesion molecule (NCAM). IHC was followed by quantitative microscopic evaluation. Descriptive and inferential statistics was applied including confidence interval (CI) analysis, Mann-Whitney U test and Spearmen correlation by IBM SPSS Statistics 22.0 software; p values less than 0.05 were regarded as statistically significant. Results. Although PR were found in all samples, the mean expression was significantly lower in multiple meningiomas (p = 0.03): 30.0% (95% CI: 10.4 - 49.8) versus 70.6% (95% CI: 56.6 - 84.7) in solitary meningiomas. ER were invariably absent in both groups. The proliferation index did not differ in solitary and multiple tumors. There was a trend (p = 0.07) to higher mean expression of NCAM in multiple meningiomas than in control group: 48.3% (95% CI: 25.8 - 70.8) versus 24.6% (95% CI: 13.2 - 36.0), respectively. The multiple meningiomas showed diverse histological types and immunophenotypes in up to 33.3% patients. Conclusions. Multiple meningiomas are characterized by significant down-regulation of PR and up-regulation of NCAM. The last finding can indicate neural differentiation and/ or peculiarities of cell adhesion and signaling that facilitate multifocal proliferation. Diverse histological types as well as PR and NCAM expression in separate meningiomas within same patient indicate independent multicentric origin.

Influence of sevoflurane anesthesia on expression of GAP-43 and NCAM in hippocampal neurons of neonatal rats

Objective To evaluate the influence of sevoflurane anesthesia on the expression of growth-associated protein 43(GAP-43)and neural cell adhesion molecule(NCAM)in hippocampal neurons of neonatal rats. Methods Thirty-six pathogen-free Sprague-Dawley rats, aged 7 weeks, weighing 15-20 g, were randomly divided into 4 groups(n=9 each)using a random number table: control group(C group), 1.5% sevoflurane 6 h group(L group), 3% sevoflurane 2 h group(H1 group)and 3% sevoflurane 6 h group(H2 group). Group L inhaled 1.5% sevoflurane in oxygen for 6 h. H1 and H2 groups inhaled 3% sevoflurane in oxygen for 2 and 6 h, respectively.Group C inhaled 30% oxygen only.When the neonatal rats were 14 days old, the rats underwent Morris water maze test for 7 consecutive days.Place navigation and spatial probe tests were carried out.After the end of Morris water maze test, the rats were sacrificed, and the hippocampus was obtained for determination of the expression of GAP-43 and NCAM in hippocampal neurons. Results Compared with group C, the escape latency was significantly prolonged, the time of staying at the original platform quadrant was shortened, and the expression of GAP-43 was down-regulated in L, H1 and H2 groups, and the frequency of crossing the original platform was decreased in L and H2 groups.There was no significant difference in NCAM expression among the four groups. Conclusion The mechanism by which sevoflurane anesthesia decreases the cognitive function may be related to down-regulated expression of GAP-43, but not related to NCAM expression in hippocampal neurons of neonatal rats. Key words: Anesthetics, inhalation; Anesthesia; Infant; Cognition disorders; GAP-43 protein; Neural cell adhesion molecules; Hippocampus; Neurons

NCAM (CD56) expression in keratin-producing odontogenic cysts: aberrant expression in KCOT.

ObjectiveTo investigate immunohistochemically the expression of neural cell adhesion molecule (NCAM), which has been identified as a signaling receptor with frequent reactivity in ameloblastomas (AB), in a series of keratin-producing odontogenic cysts (KPOCs).Material and methodsImmunohistochemical expression of NCAM, using a monoclonal antibody, was determined in a series of 58 KPOCs comprising 12 orthokeratinized odontogenic cysts (OOCs) and 46 keratocystic odontogenic tumors (KCOTs), corresponding to 40 non-syndromic KCOT (NS-KCOTs) and 6 syndromic KCOT (S-KCOTs), associated with nevic basocellular syndrome (NBCS).ResultsNCAM expression was negative in all OOCs, but 36.45% of KCOTs exhibited focal and heterogeneous expression at the basal cell level, as well as in basal budding areas and the basal cells of daughter cysts. The latter two locations were especially applicable to S-KCOTs, with focal NCAM reactivity occurring in 66.66% of cases.ConclusionsAberrant NCAM expression, in KCOTs but especially in S-KCOTs, together with its immunomorphological location, suggests that this adhesion molecule and signaling receptor plays a role in the pathogenesis of KCOTs, with a probable impact on lesional recurrence.Electronic supplementary materialThe online version of this article (doi:10.1186/s13005-015-0060-2) contains supplementary material, which is available to authorized users.

Physical and biological regulation of neuron regenerative growth and network formation on recombinant dragline silks

Recombinant spider silks produced in transgenic goat milk were studied as cell culture matrices for neuronal growth. Major ampullate spidroin 1 (MaSp1) supported neuronal growth, axon extension and network connectivity, with cell morphology comparable to the gold standard poly-lysine. In addition, neurons growing on MaSp1 films had increased neural cell adhesion molecule (NCAM) expression at both mRNA and protein levels. The results indicate that MaSp1 films present useful surface charge and substrate stiffness to support the growth of primary rat cortical neurons. Moreover, a putative neuron-specific surface binding sequence GRGGL within MaSp1 may contribute to the biological regulation of neuron growth. These findings indicate that MaSp1 could regulate neuron growth through its physical and biological features. This dual regulation mode of MaSp1 could provide an alternative strategy for generating functional silk materials for neural tissue engineering.

Cancer stem cells in hepatocellular carcinoma--an immunohistochemical study with histopathological association.

Background & objectives:Cancer stem cells (CSCs) may be responsible for tumour recurrence and resistance to chemotherapy in hepatocellular carcinoma (HCC). This study was carried out to evaluate the association between histological parameters and liver CSCs (LCSC) in HCC, and to compare distribution of liver CSCs in HCC associated with and without hepatitis B virus (HBV) infection.Methods:Seventy nine tumours (49 surgical resections from 46 patients, and 30 from autopsy) were reviewed. Immunohistochemical staining for the LCSC marker EpCAM (epithelial cell adhesion molecule), liver progenitor cell (LPC) markers CK19 (cytokeratin 19) and neural cell adhesion molecule (NCAM) were performed and were associated with histological features of tumour behaviour.Results:Thirty three tumours (41.8%) showed positive staining for EpCAM. CK19 and NCAM expression were seen in 26 (32.9%) and four (5.1%) tumours, respectively. The expression of EpCAM and CK19 was significantly associated with each other (P<0.001). EpCAM expression was significantly associated with clinical and histological features indicating aggressive tumour behaviour, including younger age of onset, higher serum alpha foetoprotein (AFP) levels, tumour cell dedifferentiation, increased mitotic activity, and vascular invasiveness. There was no significant difference in expression of EpCAM, CK19 and NCAM between HBV positive and negative HCC.Interpretation & conclusions:The LCSC marker EpCAM was expressed in less than half of HCC, was independent of HBV aetiology, and was strongly associated with clinical and histological features of aggressive tumour behaviour. Positive staining for CK19 suggests a possible LPC origin of the EpCAM positive HCCs.

Effects of polysialic acid on sensory innervation of the cornea

Sensory trigeminal growth cones innervate the cornea in a coordinated fashion during embryonic development. Polysialic acid (polySia) is known for its important roles during nerve development and regeneration. The purpose of this work is to determine whether polySia, present in developing eyefronts and on the surface of sensory nerves, may provide guidance cues to nerves during corneal innervation. Expression and localization of polySia in embryonic day (E)5–14 chick eyefronts and E9 trigeminal ganglia were identified using Western blotting and immunostaining. Effects of polySia removal on trigeminal nerve growth behavior were determined in vivo, using exogenous endoneuraminidase (endoN) treatments to remove polySia substrates during chick cornea development, and in vitro, using neuronal explant cultures. PolySia substrates, made by the physical adsorption of colominic acid to a surface coated with poly-d-lysine (PDL), were used as a model to investigate functions of the polySia expressed in axonal environments. PolySia was localized within developing eyefronts and on trigeminal sensory nerves. Distributions of PolySia in corneas and pericorneal regions are developmentally regulated. PolySia removal caused defasciculation of the limbal nerve trunk in vivo from E7 to E10. Removal of polySia on trigeminal neurites inhibited neurite outgrowth and caused axon defasciculation, but did not affect Neural Cell Adhesion Molecule (NCAM) expression or Schwann cell migration in vitro. PolySia substrates in vitro inhibited outgrowth of trigeminal neurites and promoted their fasciculation. In conclusion, polySia is localized on corneal nerves and in their targeting environment during early developing stages of chick embryos. PolySias promote fasciculation of trigeminal axons in vivo and in vitro, whereas, in contrast, their removal promotes defasciculation.