Biomedical subjects

C Decaestecker

Publications and source records attributed to C Decaestecker.

At least 19 recordsLinked to original sources

PubMed2006

The in vitro influences of neurotensin on the motility characteristics of human U373 glioblastoma cells.

Astrocytic tumours are associated with dismal prognoses due to their pronounced ability to diffusely invade the brain parenchyma. Various neuropeptides, including gastrin, are able to modulate tumour astrocyte migration. While neurotensin has been shown to influence the proliferation of glioma cells and the migratory ability of a large set of other cell types, its role in glioma cell migration has never been investigated. Neurotensin-induced modifications to the motility features of human U373 glioblastoma cells therefore constitute the topic of the present study. We evidenced that three subtypes of neurotensin receptors (NTR1, NTR2 and NTR3) are expressed in U373 glioblastoma cells, at least as far as their mRNAs are concerned. Treating U373 tumour cells with 10 nM neurotensin markedly modified the morphological patterns of these cells and also profoundly altered the organization of their actin cytoskeletons. Pull-down assays revealed that neurotensin induced the activation in U373 cells of both Rac1 and Cdc42 but not RhoA. Scratch wound assays evidenced that neurotensin (0.1 and 10 nM) very significantly inhibited wound colonization by U373 cells cultured in the absence of serum. In addition, quantitative phase-contrast videomicroscopy analyses showed that neurotensin decreases the motility levels of U373 glioblastoma cells when these cells are cultured on plastic. In sharp contrast, neurotensin stimulates the motility of U373 cells when they are cultured on laminin, which is a pro-adhesive extracellular matrix component ubiquitously secreted by glioma cells. Our data thus strongly suggest that, in addition to gastrin, neurotensin is a neuropeptide capable of modulating tumour astrocyte migration into the brain parenchyma.

Actins↗

PubMed2005

Tracking of migrating cells under phase-contrast video microscopy with combined mean-shift processes.

In this paper, we propose a combination of mean-shift-based tracking processes to establish migrating cell trajectories through in vitro phase-contrast video microscopy. After a recapitulation on how the mean-shift algorithm permits efficient object tracking we describe the proposed extension and apply it to the in vitro cell tracking problem. In this application, the cells are unmarked (i.e., no fluorescent probe is used) and are observed under classical phase-contrast microscopy. By introducing an adaptive combination of several kernels, we address several problems such as variations in size and shape of the tracked objects (e.g., those occurring in the case of cell membrane extensions), the presence of incomplete (or noncontrasted) object boundaries, partially overlapping objects and object splitting (in the case of cell divisions or mitoses). Comparing the tracking results automatically obtained to those generated manually by a human expert, we tested the stability of the different algorithm parameters and their effects on the tracking results. We also show how the method is resistant to a decrease in image resolution and accidental defocusing (which may occur during long experiments, e.g., dozens of hours). Finally, we applied our methodology on cancer cell tracking and showed that cytochalasin-D significantly inhibits cell motility.

Adenocarcinoma↗

PubMed2005

Co-expression/co-location of S100 proteins (S100B, S100A1 and S100A2) and protein kinase C (PKC-beta, -eta and -zeta) in a rat model of cerebral basilar artery vasospasm.

OBJECT: The cellular events leading to cerebral vasospasm after subarachnoid haemorrhages (SAH) involve a number of members of the protein kinase C (PKC) family. However, whereas calcium is thought to play a number of major roles in the pathophysiology of SAH, a number of PKCs function independently of calcium. We recently emphasized the potential role of the calcium-binding S100 proteins in a 'double haemorrhage' rat model of SAH-induced vasospasm. A number of S100 proteins are known to interfere directly with PKC, or indirectly with PKC substrates. We therefore investigated whether specific S100 proteins and PKCs are co-expressed/co-located in a rat model of SAH-induced vasospasm. METHODS AND RESULTS: SAH-induced vasospasm in rats (by means of a double cisternal injection of autologous blood from a rat femoral artery) distinctly modified the expression levels of calcium-dependent PKC-alpha and PKC-beta and calcium-independent PKC-eta and PKC-zeta in endothelial and smooth-muscle cells. The RNA levels of these four PKC isotypes were determined by quantitative RT-PCR. The present study reveals that, in endothelial cells, the S100B expression/location correlate well with those of PKC-eta, and those of S100A1 with PKC-beta. In smooth-muscle cells S100A2 expression/location correlate with those of PKC-eta, and those of S100B with PKC-zeta. CONCLUSION: The present data argue in favour of a joint action of the S100 protein network and the PKC signalling pathway during cerebral vasospasm.

Animals↗

PubMed2005

Human galectin-2: expression profiling by RT-PCR/immunohistochemistry and its introduction as a histochemical tool for ligand localization.

Sugar-encoded information of glyco-conjugates is translated into cellular responses by endogenous lectins. Galectins stand out against other lectin families due to their wide range of functions including cell adhesion, tissue invasion or growth regulation exerted at extracellular, membrane, cytoplasmic and nuclear sites. This remarkable versatility warrants close scrutiny of their emerging network, in this study with focus on homodimeric human galectin-2. We first detected presence of specific mRNA in various tissue types by processing post mortem and surgical specimens by RT-PCR protocols. Overlap of gene expression was noted with proto-type galectins-1 and -7 and also family members from the other two subgroups. To monitor expression on the level of protein a polyclonal anti-galectin-2 antibody was raised. Immunopositivity was semi-quantitatively assessed in sections of 209 human samples establishing an array both of normal tissues and samples with inflammation or benign/malignant growth. In general, positivity was predominantly epithelial without restriction of staining to certain tissue types, as fittingly indicated by our RT-PCR analysis. Staining was not limited to the cytoplasm but also included nuclear sites. To examine the suitability of the labeled lectin as a histochemical probe we biotinylated galectin-2 under activity-preserving conditions and introduced it to tissue profiling. Specific cytoplasmic staining proved the validity of the concept. Our results encourage systematic histopathologic studies by immuno- and lectin histochemistry, especially by adding galectin-2 as study object to galectin fingerprinting which has already yielded prognostic information on galectins-1, -3, -4 and -8 and hereby contributed to define functional overlap/divergence in this lectin family.

Antibodies↗

PubMed2004

The infrared spectrum of human glioma cells is related to their in vitro and in vivo behavior.

The present research investigates whether infrared spectra can be related to the biological characteristics of glioma cell lines. We used nine human glioma cell lines for which a series of in vitro and in vivo biological features had already been established [Glia 36 (2001) 375] and were able to show that their characteristic infrared spectra reflect their in vitro migration (i.e., motility and invasiveness) properties and their in vivo aggressiveness. More particularly, the infrared data evidenced correlations at the level of the lipid/protein ratio. These relationships were found to be tissue-dependent when controlled on seven pancreatic carcinoma cell lines. We also showed that oligodendroglial and astrocytic tumor cells, whose identification remains difficult, can easily be identified by their infrared spectra in the lipid acyl chain region as well as in the nucleic acid region. We concluded that infrared spectroscopy could usefully complement information provided by more conventional diagnostic and prognostic (e.g., morphological and molecular) approaches.

Animals↗

PubMed2004

S100A5: a marker of recurrence in WHO grade I meningiomas.

Some WHO grade I intracranial meningiomas resected from the same sites and with the same quality of resection (Simpson's grading scale) recur, while others do not. The reasons for this variability in occurrence of recurrence have not yet been determined. We therefore investigated the prognostic recurrence value of seven biological markers on a series of completely resected WHO grade I meningiomas. For this purpose, we analysed a series of 33 WHO grade I meningiomas totally resected between 1980 and 1990 (a follow-up of 10 years), including 14 cases of recurrence. The fixed tumour material from each meningioma was submitted to histochemical analyses targeting galectin-3 and its binding sites, the S100A5, S100A6 and S100B proteins, and cathepsin-B and -D. The levels of expression were assessed semi-quantitatively (in terms of the staining intensity and the labelling index) and submitted to uni- and multivariate analyses. Of all the markers investigated, only S100A5 expression can be associated with any significant prognostic value in the matter of recurrence. More particularly, the meningiomas with high levels of S100A5 staining intensity either did not recur, or recurred later than those with a low immunopositive S100A5 intensity (P = 0.004). Cox regression analyses demonstrated that this latter marker was associated with significant prognostic values independent of the patients' ages. Furthermore, the combination of the patients' ages and S100A5 staining intensity permitted the identification of a group with a particularly high risk of recurrence, that is, the patients younger than 55 and with meningiomas exhibiting low S100A5 intensities (P = 0.001). In conclusion, the S100A5 protein could play a role in the recurrence of totally resected WHO grade I meningiomas.

Adolescent↗

PubMed2003

Differential expression of S100 calcium-binding proteins in epidermoid cysts, branchial cysts, craniopharyngiomas and cholesteatomas.

AIMS: To investigate whether epidermoid cysts, branchial cysts, craniopharyngiomas and cholesteatomas express S100 proteins differentially by immunohistochemical assaying the presence of S100A1, S100A2, S100A3, S100A4, S100A5, S100A6 and S100B. METHODS AND RESULTS: Immunopositivity/negativity was recorded for each S100 protein in a series of 52 cases consisting of 12 epidermoid cysts, 12 branchial cysts, 15 adamantinomatous craniopharyngiomas and 13 acquired cholesteatomas. Except in the case of the craniopharyngiomas, immunoreactivity was assessed independently in the basal membrane and the basal, the internal and the keratin layers. Our data show that in contrast to S100B, which was rarely expressed, S100A1, S100A2, S100A4 and S100A5 were often present in these four types of epithelial lesions. S100A3 and S100A6 and, to a lesser extent, S100A5 were the most differentially expressed proteins across the different histopathological groups analysed. These three proteins are expressed more often in craniopharyngiomas and cholesteatomas, the two more aggressive types of lesions. CONCLUSIONS: This is the first study to report data on the expression of seven S100 proteins in different histopathological groups of epithelial head and neck lesions, whose precise embryological origins are still a matter of debate. S100 proteins could possibly be used as markers to target this embryonic origin, since our results show that S100A3 and S100A6 (and, to a lesser extent, S100A5) are expressed differentially across these different groups of epithelial lesions.

Adolescent↗

PubMed2002

The Ca2+-binding S100A2 protein is differentially expressed in epithelial tissue of glandular or squamous origin.

It has been previously shown that S100A2 is downregulated in tumor cells. The level of immunohistochemical S100A2 expression was therefore characterized in 424 normal and tumoral (benign and malignant) tissues of various origins, but mostly epithelial (with either glandular, squamous, respiratory or urothelial differentiation). We also investigated whether S100A2 could be co-localized with cytokeratin K14, an intermediate filament protein expressed in basal proliferative keratinocytes. Our data show that S100A2 has a low level of expression in non-epithelial tissue. In epithelial tissue S100A2 expression decreases remarkably in the tumors when compared to the normal specimens, and was correlated with the level of keratin K14. This decrease in S100A2 staining from normal to cancer cases is more pronounced in glandular than in squamous epithelial tissue. In addition, the patterns of S100A2 staining also differ between glandular and squamous tissue. These data suggest distinct functional roles for S100A2 in epithelial tissue of squamous or glandular origins.

Carcinoma, Squamous Cell↗

PubMed2002

Ploidy and chromatin pattern analysis as an aid for cervical smear diagnosis.

In the present study we used computer-assisted microscopy to analyze the morphology of Feulgen-stained cell nuclei in cell populations obtained at the same time as routinely performed cervical smears and in the same way. We investigated in a series of 110 cases whether the quantitative morphonuclear description of cytological cervical samples is able to aid pathologists to distinguish between benign and more suspect premalignant lesions. For this task nuclear DNA content, nuclear morphometry (size and anisonucleosis level) and chromatin pattern-related parameters were compiled for each specimen enrolled in the database. A set of 32 normal and 17 high-grade squamous intraepithelial lesion (HSIL) specimens (with diagnostic confirmations) were selected as references and used to establish a discriminant model on the basis of cytometry-generated variables. This model was then used to score the remaining 61 cases in our series (including cases exhibiting benign cellular changes, squamous cells of undetermined significance, low-grade SIL and cancers). The results show that a model discriminating efficiently between normal and HSIL groups can be obtained by combining 5 quantitative features (1 DNA ploidy-related, 2 morphometrical and 2 chromatin texture features). A 97% specificity and an 88% sensitivity characterized the boundary so established. When applied to new cases, the model was in fact able to correct diagnoses for cases which had been down- or up-graded on the basis of the Bethesda system, and provided scores in accordance with histological control.

Adolescent↗

PubMed2002

UPPP for snoring: long-term results and patient satisfaction.

We retrospectively survey 57 patients who underwent uvulopalatopharyngoplasty (UPPP) because of habitual snoring over a five-year period. A total of 100 patients were sent questionnaires concerning persistent snoring, excessive daytime sleepiness (EDS), body mass index (BMI) and postoperative complications. After 5 years the success rate was 53%. The mean snoring score was 16.7 preoperatively and decreased to 10.6 postoperatively. There was a relationship between the body mass index (BMI) preoperatively and the efficiency of the surgery. The mean EDS score was 11.1 before and 9.4 after surgery. UPPP in patients complaining of snoring is quite successful but the results decline significantly with time and patients should be warned of the possibility of snoring remaining or returning.

Body Mass Index↗

PubMed2001

Gastrin induces over-expression of genes involved in human U373 glioblastoma cell migration.

Astrocytic tumors are the most common and the most malignant primary tumors of the central nervous system. We had previously observed that gastrin could significantly modulate both cell proliferation and migration of astrocytoma cells. We have investigated in the present study which genes could be targeted by gastrin in tumor astrocyte migration. Using a subtractive hybridization PCR technique we have cloned genes differentially over-expressed in human astrocytoma U373 cells treated or not with gastrin. We found about 70 genes over-expressed by gastrin. Among the genes overexpressed by gastrin, we paid particular attention to tenascin-C, S100A6 and MLCK genes because their direct involvement in cell migration features. Their gastrin-induced overexpression was quantitatively determined by competitive RT-PCR technique. We also showed by means of a reporter gene system that S100A6 and tenascin-C respective promoters were upregulated after gastrin treatment. These data show that gastrin-mediated effects in glioblastoma cells occur through activation of a number of genes involved in cell migration and suggest that gastrin could be a target in new therapeutic strategies against malignant gliomas.

Actins↗

PubMed2001

Synthesis and characterization of the antitumor activities of analogues of meridine, a marine pyridoacridine alkaloid.

Marine compounds with pyridoacridine skeletons are known to exhibit interesting antitumor activities. Among these compounds, meridine has already been reported as having significant antitumor activities in vitro. We synthesized 24 analogues of meridine substituted on ring A with the aim of obtaining compounds that display significantly higher in vitro antitumor activities than meridine. The 24 compounds and meridine used as a control compound were tested at 6 different concentrations on 12 different human cancer cell lines including various histopathological types (glioblastomas and breast, colon, lung, prostate, and bladder cancers). The IC(50) value (i.e., the drug concentration inhibiting the mean growth value of the 12 cell lines by 50%) of these 25 compounds ranged over 5 log concentrations, i.e., between 10 and 0.0001 microM, with four of the compounds exhibiting a significantly higher in vitro antitumor activity than meridine. These compounds will now be subjected to further pharmacological investigation including in vivo testing on both conventional murine tumors and human tumors grafted onto nude mice.

Alkaloids↗

PubMed2001

Galectin-1 is highly expressed in human gliomas with relevance for modulation of invasion of tumor astrocytes into the brain parenchyma.

Protein (lectin)-carbohydrate interaction is supposed to be relevant for tumor cell behavior. The aims of the present work are to investigate whether galectin-1 modulates migration/invasion features in human gliomas in vitro, whether it can be detected in human gliomas immunohistochemically, and whether its expression is attributable to certain glioma subgroups with respect to invasion and prognosis. For this purpose, we quantitatively determined (by computer-assisted microscopy) the immunohistochemical expression of galectin-1 in 220 gliomas, including 151 astrocytic, 38 oligodendroglial, and 31 ependymal tumors obtained from surgical resection. We also xenografted three human glioblastoma cell lines (the H4, U87, and U373 models) into the brains of nude mice in order to characterize the in vivo galectin-1 expression pattern in relation to tumor invasion of the normal brain parenchyma. In addition, we characterized the role in vitro of galectin-1 in U373 tumor astrocyte migration and kinetics. Our data reveal expression of galectin-1 in all human glioma types with no striking differences between astrocytic, oligodendroglial, and ependymal tumors. The level of galectin-1 expression correlated with the grade in the group of astrocytic tumors only. Furthermore, immunopositivity of high-grade astrocytic tumors from patients with short-term survival periods was stronger than that of tumors from patients with long-term survivals. In human glioblastoma xenografts, galectin-1 was preferentially expressed in the more invasive parts of these xenografts. In vitro experiments revealed that galectin-1 stimulates migration of U373 astrocytes.

Adult↗

PubMed2001

Molecular characterization of cell substratum attachments in human glial tumors relates to prognostic features.

Glioma cell attachments to substratum play crucial roles in the invasion by glioma cells of normal brain tissue. These attachments are mediated through interactions between extracellular matrix (ECM) components, integrins, focal adhesion-linked molecules, and the actin cytoskeleton. In the present study, we investigate the molecular elements involved in cell substratum attachments in human glial tumors and their potential relationships to prognostic features. We used 10 human glioma cell lines, for which we characterized glial differentiation by means of quantitative RT-PCR for nestin, vimentin, and GFAP mRNA. We quantitatively determined the amounts of laminin, fibronectin, vitronectin, and thrombospondin secreted by these glioma cell lines in vitro, as well as the amount of each of the eight beta integrin subunits and the adhesion complex-related molecules, including talin, vinculin, profilin, zyxin, alpha-actinin, paxillin, and VASP. After quantification of the levels of migration and invasion of these 10 cell lines in vitro and, through grafts into the brains of nude mice, of their biological aggressiveness in vivo, it appeared that the levels of the beta 5 integrin subunit and alpha-actinin were directly related to biological aggressiveness. These experimental data were clinically confirmed because increasing immunohistochemical amounts of the beta 5 integrin subunit and alpha-actinin were directly related to dismal prognoses in the case of astrocytic tumors. In addition, we show that the beta 4 integrin subunit are expressed significantly more in oligodendrogliomas than in astrocytic tumors. A potential role for the beta 8 integrin subunit in glioma cell substratum attachments is also emphasized.

Actinin↗

PubMed2001

The levels of retinoid RARbeta receptors correlate with galectin-1, -3 and -8 expression in human cholesteatomas.

Cholesteatoma is a benign disease characterized by the presence of an unrestrained growth and the accumulation of keratin debris in the middle ear cavity. This often recurs, even when surgical resection is thought to be complete. In a previous study we showed that cholesteatomas with the highest apoptotic indices recurred more rapidly and also exhibited a high level of p53 immunopositive cells. In view of their relevance to the characterization of the cell differentiation status, the present study focuses on the expression of retinoid acid receptors (RARs) and galectins in human cholesteatomas. Retinoids control the differentiation processes in keratinocytes while galectins play strikingly modulatory roles at apoptosis and cell adhesion levels in a wide variety of tissue (embryonic, normal and neoplastic). To clarify the expression of these two protein families in human cholesteatomas we examined and quantified the levels of immunohistochemical expression of RARalpha, beta and gamma, and also galectin-1, -3 and -8 in a series of 70 human cholesteatomas. Our data show clearly that predominantly RARbeta and galectin-1 were expressed. The RARgamma concentration was significantly lower than that of the RARalpha; this was also observed for the galectin-8 concentration in comparison with the galectin-3 one. Furthermore, the level of RARbeta expression correlated highly (P=0.00001) with the level of galectin-8 expression, which also correlated significantly with the level of RARalpha and RARgamma expression. In addition, this parameter also correlated with the level of galectin-1 and galectin-3 expression. These data suggest that cholesteatomas may originate in an undifferentiated population of keratinocytes, and that a relation may exist between retinoid activity and galectins.

Adult↗

PubMed2001

S100A2, a putative tumor suppressor gene, regulates in vitro squamous cell carcinoma migration.

It has been previously shown that S100A2 is down-regulated in tumor cells and can be considered a tumor suppressor. We have recently shown that this down-regulation can be observed particularly in epithelial tissue, where S100A2 expression decreases remarkably in tumors as compared with normal specimens. In the present paper we investigate whether S100A2 could play a tumor-suppressor role in certain epithelial tissues by acting at the cell migration level. To this end, we made use of five in vitro human head and neck squamous cell carcinoma lines in which we characterized S100A2 expression at both RNA and protein level. To characterize the influence of S100A2 on cell kinetic and cell motility features, we used two complementary approaches involving specific antisense oligonucleotides and the addition of S100A2 to the culture media. The different expression analyses gave a coherent demonstration of the fact that the FADU and the RPMI-2650 cell lines exhibit high and low levels of S100A2 expression, respectively. Antisense oligonucleotides (in FADU) and extracellular treatments (in RPMI) showed that, for these two models, S100A2 had a clear inhibitory influence on cell motility while modifying the cell kinetic parameters only slightly. These effects seem to be related, at least in part, to a modification in the polymerization/depolymerization dynamics of the actin microfilamentary cytoskeleton. Furthermore, we found evidence of the presence of the receptor for advanced glycation end-products (RAGE) in RPMI cells, which may act as a receptor for extracellular S100A2. The present study therefore presents experimentally based evidence showing that S100A2 could play a tumor-suppressor role in certain epithelial tissues by restraining cell migration features, at least in the case of head and neck squamous cell carcinomas.

Actins↗

PubMed2001

Distinct differences in binding capacity to saccharide epitopes in supratentorial pilocytic astrocytomas, astrocytomas, anaplastic astrocytomas, and glioblastomas.

We monitored the expression of glycan-binding sites on a panel of 10 biotinylated neoglycoconjugates by means of quantitative computer-assisted microscopy to further study the molecular mechanisms in the extensive infiltration of the surrounding brain parenchyma by most astrocytic tumors. Three distinct histological compartments were analyzed for each of the 108 astrocytic tumors (15 pilocytic astrocytomas (WHO grade I), 25 astrocytomas (WHO grade II), 30 anaplastic astrocytomas (WHO grade III), and 38 glioblastomas (WHO grade IV) included in our series. These compartments were tumors (nonperivascular tumor astrocytes), perivascular tumor astrocytes, and blood vessel walls. Clear differences were observed between the pilocytic and the diffuse astrocytic tumors. Furthermore, malignant progression in the latter category was paralleled by a decrease in cells' ability to bind distinct sugar epitopes, especially the D-GalNAc(alpha1-3)-D-GalNAc-beta1-R determinant of the Forssman pentasaccharide in tumors, the alpha-L-fucose in perivascular tumor areas, and the beta-D-glucose in tumor vessel walls. Markedly, the level of binding site expression for alpha-D-mannose decreased in the tumors, the perivascular tumor areas, and the vessel walls. These glycohistochemical results imply the functional relevance of protein-carbohydrate interactions in this tumor system.

Adult↗

PubMed2001

The levels of expression of galectin-3, but not of galectin-1 and galectin-8, correlate with apoptosis in human cholesteatomas.

OBJECTIVES: To investigate whether galectins 1, 3, and 8 are expressed in human cholesteatomas and whether any such expression does correlate with the level of apoptosis, which is, as we have previously shown, predictive of recurrence.7 STUDY DESIGN: The analysis of 52 cholesteatomas resected by the same surgeon by means of canal wall up and canal wall down procedures. METHODS: The immunohistochemical levels of expression of galectins 1, 3, and 8 were quantitatively determined (using computer-assisted microscopy) on conventional histological slides by means of specific anti-galectin-1, anti-galectin-3, and anti-galectin-8 antibodies. The level of apoptosis in each cholesteatoma under study had already been determined 7 by means of the in situ labeling of nuclear DNA fragmentation (Tolt-mediated dUTP nick end labeling [TUNEL] staining). RESULTS: Galectin-1 was expressed markedly in both the epithelial and the connective tissue areas of all the cholesteatomas under study. The levels of expression of galectin-3 and galectin-8 were considerably lower than that of galectin-1. The level of expression of galectin-3 correlated both highly and positively with the level of apoptosis. CONCLUSIONS: An upregulation of galectin-3 (known to have an antiapoptotic and antianoikis effect in certain model systems) expression, which is associated with pronounced apoptotic activity, could have a physiologically protective effect against the characteristically substantial apoptotic features occurring in recurrent cholesteatomas.

Antigens, Differentiation↗