Biomedical subjects

Robert Kiss

Publications and source records attributed to Robert Kiss.

At least 55 records · Page 3Linked to original sources

PubMed2003

Refined prognostic evaluation in colon carcinoma using immunohistochemical galectin fingerprinting.

BACKGROUND: Knowledge of the expression of the galectins in human colon carcinomas is mainly restricted to galectin-3 and, to a lesser extent, galectin-1. The current study analyzed the prognostic values contributed by galectin-1, galectin-3, galectin-4, and galectin-8 in cases of colon carcinoma. METHODS: The authors selected 55 colon carcinomas (including 10 Dukes A, 16 Dukes B, 15 Dukes C, and 14 metastatic tumors that the authors labeled "Stage D"). The immunohistochemical levels of expression of the four galectins were determined quantitatively by means of computer-assisted microscopy. RESULTS: The data from the current study indicate that the four galectins under study are associated with significant and separate prognostic values that depend on the Dukes stage of the colon tumor. In particular, the authors observed a significant prognostic value associated with galectins-1, -3, and -4 in Dukes A and B colon tumors. In addition, significant prognostic value also was associated with galectin-8 in Dukes C and D colon tumors. The prognostic values associated with the levels of expression of galectin-1 and galectin-4 in Dukes A and B tumors appear to be independent of the Dukes stage. The same feature was observed when galectin-4 and galectin-8 were analyzed in the complete series. CONCLUSIONS: The data from the current study strongly suggest that galectins-1, -3, and -4 may be involved in the early stages of human colon carcinoma development and that galectin-8 is involved in the later stages.

Adult↗

PubMed2003

Upregulation of galectins-1 and -3 in human colon cancer and their role in regulating cell migration.

To probe the potential contribution of beta-galactoside-contributing epitopes and receptor proteins (gal-1 and gal-3) to colon malignancy, we first examined the expression of galectins and binding sites in clinical specimens by lectin and immunohistochemistry. Sixty-seven colonic surgical resections were studied, including 10 normal, 10 mild dysplasias, 10 severe dysplasias and 37 cancers. gal-1 and gal-3 were expressed in variable amounts in the epithelial cells and the connective tissue of normal colon. Their expression significantly increased with the degree of dysplasia, suggesting that gal-1 and gal-3 and their binding sites are related to malignant progression, while gal-8 has been associated with suppressor activity. To study the functional aspects, the influence of these galectins on the migration of 4 human colorectal cancer cell lines (HCT-15, LoVo, DLD-1, CoLo201) was studied. In agreement with histopathologic monitoring, these tumor cells were found to produce gal-3, while only CoLo201 was positive for gal-1. Except for DLD-1 and gal-1, the lines exhibited gal-1 binding sites on the surface, prompting study by computer-assisted videomicroscopy of the effect on cell migration of the presence of galectin on the culture substrate. The level of cell migration for HCT-15, LoVo and CoLo201 cells was significantly reduced by 0.15 microg/cm(2) gal-1, and the presence of a blocking antibody at least reduced this effect. gal-3 significantly reduced cell migration in all 4 of the in vitro cell lines.

Adenocarcinoma↗

PubMed2003

Expression patterns of galectin-1 and galectin-3 in nasal polyps and middle and inferior turbinates in relation to growth regulation and immunosuppression.

BACKGROUND: The term nasal polyposis describes benign growth processes in the nasal and sinus mucosa, which are mainly located in the middle meatus and never in the inferior meatus. As a step to define the biochemical determinants relevant for growth regulation, we focused on endogenous lectins known for anti-apoptotic (galectin-3) and immunomodulatory (galectin-1) activities. DESIGN: Using computer-assisted microscopy, we performed an immunohistochemical investigation defining the quantitative parameters of expression of galectin-1 and galectin-3 in 10 nasal polyps, 10 middle turbinates, and 10 inferior turbinates, all of which were obtained from surgical resection. RESULTS: Our data show that galectin-3 expression is markedly (P<.001) higher in nasal polyps than in turbinates. No relation to the allergic status was discovered. Galectin-1 expression is higher in nasal polyps than in middle turbinates (P<.001) in nonallergic patients compared with allergic ones (in glandular epithelium, P =.009; in connective tissue, P =.006). The lowest galectin-1 expression was observed in the middle turbinate. CONCLUSIONS: These data are in line with a positive influence of galectin-3 on growth and an immunoregulatory role of galectin-1, mimicking an increased expression dependent on glucocorticoid.

Adjuvants, Immunologic↗

PubMed2003

Postnatal maturation of the dog stria vascularis-- an immunohistochemical study.

The lateral wall of the dog cochlear duct was investigated by classical staining and immunohistochemistry for NaK/ATPase beta2 isoform, cytokeratins (Cks), vimentin, nestin, and S100A6 during the postnatal cochlear maturation, i.e., from birth to postnatal day 110. The dog stria vascularis was immature at birth. Fine melanin granules were evident in the stria from the second week of life, and melanin concentration increased drastically beyond the first month. The marginal cells were NaK/ATPase- and Ck-positive; intermediate cells were either nestin- and S100A6-positive or vimentin-positive; the basal cells were vimentin-positive; the capillary endothelium showed vimentin and nestin labeling; the cell layer underlying the stria was nestin-positive. The fibrocytes of the spiral ligament and spiral prominence expressed nestin and vimentin. The epithelial cells overlaying the spiral prominence and the external sulcus were Ck-positive, and transiently nestin- and vimentin-positive. Double immunolabeling, for S100A6 and either nestin, vimentin, or NaK/ATPase, and for nestin and vimentin suggested the presence of two distinct intermediate cell types. The results enabled us to differentiate the cell types forming the lateral wall of the dog cochlear duct, and to follow their postnatal maturation. This study may form a basis for future investigations about spontaneous cochleosaccular degeneration in dogs. This species is an important companion animal, and a possible model for the study of comparable diseases in humans.

Animals↗

PubMed2003

111In-oxine and 99mTc-HMPAO labelling of antigen-loaded dendritic cells: in vivo imaging and influence on motility and actin content.

In cancer vaccination trials, antigen-loaded dendritic cells (DCs) are usually injected intradermally and are expected to rapidly move to a regional lymph node where antigen presentation should occur. In this study we investigated the influence of indium-111 oxine (111In) and technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) labelling on the motility and actin content of antigen-loaded DCs in parallel with in vivo migration in humans. Human autologous monocyte-derived DCs loaded with a tumour antigen were labelled with 111In (0.11, 0.37 or 0.74 MBq/10(7) DCs) or 99mTc-HMPAO (18.5 or 185 MBq/10(7) DCs). 111In labelling was much more stable than 99mTc-HMPAO labelling. Quantitative videomicroscopy showed that the mean distance of displacement of DCs increased in accordance with the 111In activity used for labelling. Monomeric (G) and filamentous (F) actin content of DCs evaluated by quantitative immunofluorescence demonstrated that the ratio of filamentous to globular actin content in labelled DCs increased significantly in accordance with the activity used for labelling with both tracers. Twelve patients enrolled in a phase I/II vaccination trial received injections of 10(7) antigen-loaded DCs labelled with either 0.74 MBq of 111In (group A, n=6/12) or 18.5 MBq of 99mTc-HMPAO (group B, n=6/12) in the proximal part of the legs, one intradermally on one side, one subcutaneously on the opposite side. In three of the six patients of each group, antigen-loaded DCs were incubated with monophosphoryl lipid A (MPL) just before the labelling, in order to initiate the maturation process (subgroup MPL+). Only one MPL+ patient of group A exhibited faint focal uptake in the inguinal region on the late images. Group B presented a more complex pattern of radioactivity distribution (early bladder activity without brain uptake) indicating that 99mTc-HMPAO is not a suitable radiopharmaceutical for labelling of loaded DCs. The activity cleared from DCs as a labelled molecule different from the lipophilic 99mTc-HMPAO. Only one of the six patients had nodular inguinal uptake on the intradermally injected side (DCs not incubated with MPL). In conclusion, the present study did not demonstrate migration of loaded labelled DCs from intradermal or subcutaneous sites of injection to regional lymph nodes. This provides an indication that a large proportion of antigen-loaded DCs, as used in current human trials for cancer therapy, may not reach regional lymph nodes.

Actins↗

PubMed2003

Binding sites for Lewis antigens are expressed by human colon cancer cells and negatively affect their migration.

In colon cancer, endothelial cell selectins can promote tumor cell attachment via interactions with sialylated Lewis antigens present at the surface of tumor cells, thereby facilitating tumor cell arrest and transmigration into the extravascular space. However, it is not known whether Lewis antigens interact with colon tumor cells and modify their migration. Our aim was to detect the presence of binding sites on human tumor cells for Lewis(a/x) antigens and their sialylated derivatives in vitro and in vivo and to analyze their influence on migration of colon cancer cells. The immunocytochemical and histochemical levels of expression of the four Lewis antigens were quantitatively determined in four human colon cancer cell lines and in in vivo nude mice xenografts. The levels of expression of specific binding sites for these sugar epitopes were determined by synthetic neoglycoconjugates. The influence of binding of these carbohydrate ligands on cancer cell migration was quantitatively evaluated by computer-assisted phase-contrast videomicroscopy performed on Matrigel culture supports either left uncoated or coated with neoglycoconjugate presenting synthetic Lewis(a), sialyl Lewis(a), Lewis(x), or sialyl Lewis(x) antigens. The influence of the calcium concentration in the culture medium on the Lewis antigen-mediated effects was checked. Human colon cancer cells expressed significant amounts of specific binding sites detected by the synthetic probes in addition to the oligosaccharide epitopes. The expression levels differed considerably between the four cell lines and between in vitro and in vivo specimens. Cell migration analysis revealed that the four Lewis antigens markedly decreased the levels of migration of the HCT-15 and LoVo cancer cells. This effect depends on the calcium concentration in the culture medium. Binding sites for Lewis epitopes are present on colon cancer cells. The functional relevance of these sites is indicated by the negative influence on cell migration of a matrix containing the oligosaccharides as ligand parts.

Animals↗

PubMed2003

Prognostic values of galectin-3 and the macrophage migration inhibitory factor (MIF) in human colorectal cancers.

This study aims to investigate whether the immunohistochemical levels of expression of galectin-3 and the macrophage migration inhibitory factor (MIF) are associated with prognostic values in human colorectal tumors. This was performed on 99 specimens including 69 colorectal tumors (17 Dukes A, 19 Dukes B, 15 Dukes C and 18 metastatic tumors that we labeled as D), 10 hepatic metastases from colorectal cancers and 20 normal specimens (biopsies). The immunohistochemical levels of expression of MIF and galectin-3 were quantified on routine histological slides by means of computer-assisted microscopy. Separate analyses were performed on epithelial and connective tissue. The levels of expression of both MIF and galectin-3 were very significantly higher in epithelial tumor tissue when compared with normal epithelial specimens. A positive and significant correlation between MIF and galectin-3 expression was evidenced in connective tumor tissue, and in particular in the cases associated with short survival periods (less than 5 years). In the case of the Dukes A or B tumors, we established two new prognostic groups (labeled I and II) on the basis of the levels of galectin-3 expression measured in the tumor epithelium. In the case of the Dukes C or D tumors, we established two other prognostic groups (labeled III and IV) on the basis of the levels of MIF expression measured in the connective tissue. Kaplan-Meyer analyses confirmed the additional prognostic values (as compared with conventional clinical staging) given by this new classification (groups I to IV). They show that the Dukes A or B tumors characterized by low levels of galectin-3 expression in the tumor epithelium are associated with significantly better prognoses than those characterized by high levels. In addition, the Dukes C or D tumors characterized by high levels of MIF expression in the connective tumor tissue are associated with significantly better prognoses than those characterized by low levels. In conclusions, MIF and galectin-3 expression levels in colorectal tumors are related to their levels of biological aggressiveness. These markers could be used to identify patients at risk, for whom more aggressive adjuvant therapy seems to be indicated.

Adenocarcinoma↗

PubMed2003

Characterization of gastrin-induced cytostatic effect on cell proliferation in experimental malignant gliomas.

OBJECTIVE: Growth patterns of astrocytic tumors can be modulated in vitro by gastrin. In this study, the influence of gastrin on the in vitro cell cycle kinetics and the in vivo growth features of three experimental malignant gliomas was investigated. METHODS: Gastrin-induced influence on overall growth was assayed in vitro by means of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium colorimetric assay for human U373 and rat C6 gliomas and for rat 9L gliosarcoma. Although cell cycle analyses were performed by means of computer-assisted microscope analyses of Feulgen-stained nuclei, the gastrin-induced effects of the levels of expression of cyclins D3 and E, CDK2, CDK4, CDK5, CDK7, p15, p16, E2F1, and E2F2 were assayed by means of quantitative Western blot test. The presence of ribonucleic acids for the CCK(B) and CCK(C) gastrin receptors in the U373, C6, and 9L models was assayed by means of quantitative reverse transcriptase-polymerase chain reaction, and the presence or absence of ribonucleic acids for CCK(A) receptor was checked by means of conventional polymerase chain reaction. The influence of gastrin was also characterized in vivo in terms of the survival periods of conventional rats orthotopically grafted with the C6 and 9L models and nude rats with the U373 model. RESULTS: Gastrin significantly decreased the overall growth rate in the rat C6 and the human U373 high-grade astrocytic tumor models with either CCK(B) or CCK(C) gastrin receptor but not in the 9L rat gliosarcoma, which had no CCK(B) gastrin receptor (but had CCK(A) receptor) and only weak amounts of CCK(C) receptor. This effect seems to occur via a cytostatic effect; that is, an accumulation of tumor astrocytes occurs in the G(1) cell cycle phase. The cytostatic effect could relate to a gastrin-induced decrease in the amounts of the cyclin D3-CDK4 complex in both C6 and U373 glioma cells. In vivo, gastrin significantly increased the survival periods of C6 and U373 glioma-bearing rats, but not of 9L gliosarcoma-bearing rats. CONCLUSION: Gastrin is able to significantly modify the growth levels of a number of experimental gliomas.

Animals↗

PubMed2003

Effect of hydrophilic components of the extracellular matrix on quantifiable diffusion-weighted imaging of human gliomas: preliminary results of correlating apparent diffusion coefficient values and hyaluronan expression level.

OBJECTIVE: The purpose of this study was to evaluate the relationship between apparent diffusion coefficient (ADC) measured by MR imaging and the level of immunohistochemical expression of hyaluronan or hyaluronic acid as one of the main hydrophilic components of the extracellular matrix in brain glial tumors. MATERIALS AND METHODS: Nineteen patients with primary glial brain tumors were included in the study. Mean ADC values were calculated in all tumors and were normalized with the ADC values of the contralateral normal-appearing brain ratios. All tumors underwent surgical resection, and the histologic diagnosis was based on the analysis of the surgical specimen. Mean values of the labeling index of hyaluronan (LI-HA) were calculated to determine quantifiably the histochemical expression of hyaluronan in the tumor. The mean ADC values and the mean ADC ratios (ADC(ratio)) of the tumors were then correlated to the mean values of the LI-HA. RESULTS: The mean ADC (93 x 10(-5) mm(2)/sec) and the mean ADC(ratio) (1.25) of the high-grade glial tumors were significantly lower than the mean ADC (123 x 10(-5) mm/sec) and the mean ADC(ratio) (1.64) of the low-grade glial tumors (p < 0.01). The mean LI-HA (72.8%) was also significantly lower in the high-grade gliomas than the mean LI-HA (93.4%) in the low-grade gliomas (p < 0.001). A positive correlation was found between mean ADC values and the mean LI-HA (tau = 0.35, p < 0.05) and also between the mean ADC(ratio) and the mean LI-HA (tau = 0.33, p < 0.05). CONCLUSION: Hyaluronan as one of the main hydrophilic components of the extracellular matrix in gliomas likely contributes to differences in the ADC values between high- and low-grade glial tumors.

Brain↗

PubMed2003

Characterization of the levels of expression of retinoic acid receptors, galectin-3, macrophage migration inhibiting factor, and p53 in 51 adamantinomatous craniopharyngiomas.

OBJECT: Craniopharyngiomas are histopathologically defined as benign tumors that can behave very aggressively at the clinical level. They can originate from different types of embryonal epithelial tissue in which correct spatiotemporal regulation has been disrupted at the effector production level. The goal of this study was to determine the efficacy of using selected biological markers to distinguish between recurring and nonrecurring craniopharyngiomas. METHODS: The authors used computer-assisted microscopy to determine quantitatively the immunohistochemical levels of expression of selected markers, including retinoic acid receptors (RARs), as response elements to retinoic acid in a series of 51 adamantinomatous craniopharyngiomas. These tumors may also originate as the result of physiological defects in the apoptosis-mediated elimination of embryological remnants of epithelial tissue. Galectin-3, p53, and the macrophage migration inhibiting factor (MIF) are known to play crucial roles in these processes. The authors quantitatively determined the levels of expression of these substances in this series of 51 craniopharyngiomas. The data show that all craniopharyngiomas were immunoreactive for RARalpha, whereas their immunoreactivity for RARbeta and RARgamma varied dramatically from one case to another. Craniopharyngiomas with low levels of RARbeta and high levels of RARgamma are more likely to recur than those with higher levels of RARbeta and lower levels of RARgamma. Rapidly recurring craniopharyngiomas also show significantly lower levels of expression of galectin-3 and MIF than nonrecurring or slowly recurring cases. Few tumors exhibited p53 immunopositivity. CONCLUSIONS: The data indicate that even in the so-called adamantinomatous group of craniopharyngiomas, several subgroups with different clinical behavior patterns can be identified on the basis of differentiation markers relating mainly to the presence or absence of RARbeta and RARgamma.

Adolescent↗

PubMed2003

Determination of RNA expression for cholecystokinin/gastrin receptors (CCKA, CCKB and CCKC) in human tumors of the central and peripheral nervous system.

Gastrin (G17) belongs to the cholecystokinin (CCK) peptide family widely distributed in the brain, and we were the first to show that it significantly modulates the growth and migration features of tumor astyrocytes. Conflictual data have been published as to whether CCKA, CCKB and CCKC receptors are, or are not, present in tumors of the central and peripheral nervous system (CPNS) in general, and in gliomas in particular. In the present study we employed polymerase chain reaction (PCR) on a series of 29 CNPS tumors, including 20 gliomas (17 astrocytic and 3 oligodendroglial tumors), 4 schwannomas and 5 meningiomas to investigate whether RNAs were present or absent in the case of these CCKA, CCKB and CCKC receptors. The presence of the three CCK receptor subtypes was also assayed on three experimental models, i.e. the U373 human glioma, the C6 rat glioma and the 9L rat gliosarcoma. The data show that 9/20 (45%) of the gliomas exhibited RNAs for the CCKB receptor as did the C6 rat glioma, 13/20 (65%) RNAs for the CCKC receptor as did the U373 human glioma and the 9L rat gliosarcoma. Of the 20 gliomas, 17 (85%) expressed RNAs for either the CCKB or the CCKC receptor (or both), a feature which was also observed in the experimental models. One schwannoma and one meningioma exhibited RNAs for the CCKB receptor, while 4/4 schwannomas and 4/5 meningiomas showed RNAs for the CCKC receptor. None of the gliomas, schwannomas or meningiomas exhibited RNAs for the CCKA receptor, which were found in the 9L rat gliosarcoma model only. These data emphasize that 85% of the gliomas under study and 86% (25/29) of the tumors of the central and peripheral nervous system exhibited CCKB and/or CCKC receptors. This therefore suggests an important role for gastrin in the biological development of these tumors.

Animals↗

PubMed2002

Impact of cell culture process changes on endogenous retrovirus expression.

Cell culture process changes (e.g., changes in scale, medium formulation, operational conditions) and cell line changes are common during the development life cycle of a therapeutic protein. To ensure that the impact of such process changes on product quality and safety is minimal, it is standard practice to compare critical product quality and safety attributes before and after the changes. One potential concern introduced by cell culture process improvements is the possibility of increased endogenous retrovirus expression to a level above the clearance capability of the subsequent purification process. To address this, retrovirus expression was measured in scaled down and full production scaled Chinese hamster ovary (CHO) cell cultures of four monoclonal antibodies and one recombinant protein before and after process changes. Two highly sensitive, quantitative (Q)-PCR-based assays were used to measure endogenous retroviruses. It is shown that cell culture process changes that primarily alter media components, nutrient feed volume, seed density, cell bank source (i.e., master cell bank vs. working cell bank), and vial size, or culture scale, singly or in combination, do not impact the rate of retrovirus expression to an extent greater than the variability of the Q-PCR assays (0.2-0.5 log(10)). Cell culture changes that significantly alter the metabolic state of the cells and/or rates of protein expression (e.g., pH and temperature shifts, NaButyrate addition) measurably impact the rate of retrovirus synthesis (up to 2 log(10)). The greatest degree of variation in endogenous retrovirus expression was observed between individual cell lines (up to 3 log(10)). These data support the practice of measuring endogenous retrovirus output for each new cell line introduced into manufacturing or after process changes that significantly increase product-specific productivity or alter the metabolic state, but suggest that reassessment of retrovirus expression after other process changes may be unnecessary.

Animals↗

PubMed2002

Extracellular S100A4 stimulates the migration rate of astrocytic tumor cells by modifying the organization of their actin cytoskeleton.

In previous studies, we have shown that numbers of S100 calcium-binding proteins (including S100A4) are expressed differentially in astrocytic tumors according to their levels of malignancy. S100A4 is involved in tumor progression, cell migration and metastasis. This protein is able to play extracellular roles such as neuritogenic and angiogenic activities. The present study aims to investigate the possible role played by extracellular S100A4 in the in vitro migration of astrocytic tumor cells. The speed and rate of migration of living cells were measured using computer-assisted videomicroscopy. In parallel, we also analyzed the effects of extracellular S100A4 on the organization of the actin cytoskeleton and the expression of a number of its molecular regulators. These included small Rho-GTPases (RhoA, Rac1 and Cdc42) and some of their direct effectors (mDia and N-WASP), and also actin-binding proteins such as profilin and alpha-actinin. Our data demonstrate the influence of S100A4 on astrocytic tumor cells with respect to these different aspects. Indeed, we show that extracellular S100A4 treatments decrease both the amount of polymerized F-actin and the levels of expression of RhoA, mDia and profilin. While a decrease in the Cdc42 and N-WASP expression was also observed, the Rac1 expression remained unchanged. All these activities, which result in the stimulation of cell motility, contribute to the understanding of the extracellular role of S100A4.

Actin Cytoskeleton↗

PubMed2002

Galectins and cancer.

The galectins are a family of proteins that are distributed widely in all living organisms. All of them share galactose-specificity. At present, 14 members of the family are characterized in mammals. The galectins have been implicated in many essential functions including development, differentiation, cell-cell adhesion, cell-matrix interaction, growth regulation, apoptosis, RNA splicing, and tumor metastasis. Although efforts have mostly focused on the possible function of galectins in tumor development and invasiveness, their precise role in this field is still debated. This review discusses the recent way in which the expression of galectins and galectin-binding sites may affect the behavior of a variety of human neoplastic tissues.

Adipose Tissue↗

PubMed2002

Synthesis and in vitro antitumor activity of novel ring D analogues of the marine pyridoacridine ascididemin: structure-activity relationship.

Marine compounds with pyridoacridine skeletons are known to exhibit interesting antitumor activities. Ascididemin has already been reported as displaying significant antitumor activities in vitro and has also been found to have a relatively high global toxicity in vivo. We synthesized a series of 16 analogues (among which 11 compounds were different from previously described ones) with the aim of developing new anticancer agents with significantly improved efficacy/tolerability ratios. These compounds were obtained either by total synthesis from 5,8-quinolinedione and substituted 2-aminoacetophenones or by the direct substitution of ascididemin. The different compounds and ascididemin used as the control compound were tested at six different concentrations on 12 different human cancer cell lines of 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 compounds ranged over five log concentrations, i.e., between 10 000 and 0.1 nM. For several new chemical entities, the antitumor activity (determined in vitro) and tolerability (determined in vivo) were superior to those of the parent alkaloids, i.e., ascididemin and 2-bromoleptoclinidone.

Acridines↗

PubMed2002

Evaluation of the efficiency of chemotherapy in in vivo orthotopic models of human glioma cells with and without 1p19q deletions and in C6 rat orthotopic allografts serving for the evaluation of surgery combined with chemotherapy.

BACKGROUND: Malignant gliomas of the central nervous system remain associated with dismal prognoses because of their diffuse invasion of the brain parenchyma. Very few experimental models that mimic clinical reality are available today to test potentially new therapies. The authors set up experimental in vivo glioma models of anaplastic astrocytomas of human and rat origins and anaplastic oligodendroglioma of human origin. Standard hospital chemotherapies were employed to test the validity of these models. METHODS: Three glioma cells lines obtained from the American Type Culture Collection (i.e., human Hs683 and U373 cells and rat C6 cells) were implanted into nude mouse brains (Hs683 and U373 cells) and rat brains (C6 cells). The astrocytic nature, as opposed to the oligodendrocytic nature, of the Hs683 and U373 models was investigated by using quantitative (computer-assisted microscopy) immunohistochemical characterizations of nestin, vimentin, glutathione-S-transferase alpha (GSTalpha), GSTmu, GSTpi, and p53 expression. Comparative genomic hybridization (CGH) was employed to investigate 1p19q losses. Chronic administrations of carmustine (BCNU), fotemustin, or temozolomide were assayed in the xenografted U373 and Hs683 models. Both BCNU-related chemotherapy and surgery were assayed in the C6 model. RESULTS: The quantitative phenotypic analyses pointed to the oligodendroglial nature of the Hs683 cell line and the astrocytic nature of the U373 cell line. The Hs683 cells exhibited 1p19q losses, whereas the U373 cells did not. BCNU, fotemustin, and temozolomide dramatically increased the time of survival of the Hs683 oligodendroglioma-bearing mice, whereas temozolomide only induced a weak but nevertheless statistically significant increase in the U373 glioma-bearing mice. In the C6 rat glioma model, surgery and BCNU chemotherapy were more efficient than either treatment alone. CONCLUSIONS: The in vivo models of gliomas of the central nervous system developed in the current work best mimicked clinical reality. They can be used either to identify new therapies against human gliomas or to optimize existing therapies.

Animals↗

PubMed2002

Calbindin-d(28k): a marker of recurrence for medulloblastomas.

BACKGROUND: The expression of the Ca(2+)-binding protein calbindin-D(28k) was analyzed in medulloblastomas in relation to clinical features and other biologic markers related to cell proliferation, differentiation, p53, and cerebellar developmental regulated gene expression. METHODS: Immunohistochemistry was carried out on histologic slides from a first retrospective series of 29 nonmetastatic and 10 metastatic medulloblastoma formalin-fixed, paraffin-embedded tissues, using specific antibodies against calbindin-D(28k), calretinin, alpha-parvalbumin and beta-parvalbumin, and S100 proteins. Informed consent was obtained from the subjects and/or guardians. Other biologic markers for differentiation, cell proliferation, the expression of the p53 tumor suppressor gene protein, and cerebellar developmental regulated genes were similarly investigated. A second series of 16 medulloblastomas from young patients (younger than 15 years) was added in order to validate the results obtained in the first series. RESULTS: Of all the markers investigated, only calbindin-D(28k) was significantly associated with prognosis. Survival and remission (i.e. recurrence free) time analysis performed on all the cases (n = 55) confirmed a high risk of death (P = 0.004) and recurrence (P = 0.003) associated with calbindin-positivity. As calbindin-positivity was predominantly observed in tumors from young patients, the authors confirmed its prognostic value in the subgroup of patients younger than 15 years (n = 37). Cox regression analysis showed a significant and independent prognostic value for calbindin expression and, to a lesser extent, the type of surgery (total or subtotal). Three risk groups were thus identified, distinguishing among the cases characterized by a total resection and calbindin-negativity (good prognosis), by a subtotal resection and calbindin-negativity (intermediary), and by calbindin-positivity (bad prognosis). CONCLUSIONS: The current study suggests that calbindin-positive medulloblastomas represent a subclass of aggressive tumors more frequently seen in younger patients.

Adolescent↗

PubMed2002

3-Aryl-2-quinolone derivatives: synthesis and characterization of in vitro and in vivo antitumor effects with emphasis on a new therapeutical target connected with cell migration.

Among 25 3-aryl-2-quinolone derivatives synthesized, the antitumor activity of some of them was characterized both in vitro and in vivo. In this series, no compound appeared to be cytotoxic in vitro, as was known by the colorimetric MTT assay carried out on 12 distinct human cancer cell lines obtained from the American Type Culture Collection. Indeed, the concentration values decreasing the growth of the 12 cell lines by at least 50% (IC(50) index) were always higher than 10(-5) M. We then made use of a computer-assisted phase-contrast videomicroscopy system to quantitatively determine in vitro the level of migration of living MCF-7 human breast cancer cells. For example, at 10(-7) M, compounds 7, 13, 16, and 28 markedly decreased the migration level of these MCF-7 human breast cancer cells. The in vivo determination of the maximum tolerated dose showed that all compounds tested were definitively nontoxic. When the nontoxic, antimigratory compound 16 was combined with either doxorubicin or etoposide, two cytotoxic compounds routinely used in the clinic, this led to additive in vivo benefits from this treatment (as compared to individual administrations of the drugs) when the MXT mouse mammary adenocarcinoma was used. Thus, nontoxic antimigratory compounds, including the 2-quinolone derivatives synthesized here, can actually improve the efficiency of antitumor treatment when combined with conventional cytotoxic agents.

Adenocarcinoma↗