Publication practices and standards: recommendations from GSK Vaccines' author survey.

BACKGROUND: Evolving standards of good publication practice (GPP) and a survey conducted in 2009 of authors, who were investigators and researchers not employed by the company prompted changes to GSK Vaccines' publication practices. We conducted a follow-up survey in 2012 to assess the company's revised practices and to evaluate understanding of GPP among investigators and researchers who had previously authored at least one publication in collaboration with GSK Vaccines. METHODS: The 50-question web-based survey addressed authoring practices and transparency of decision-making. Investigators and researchers (n = 1,273) who had authored at least one publication reporting on GSK Vaccines-sponsored human research since 2007, were invited to participate. Responses to 37 closed questions are presented. The remaining 13 questions were open-ended or did not concern publication practices. RESULTS: A total of 415 external authors (32.6%) responded. International Committee of Medical Journal Editors (ICMJE) authorship criteria were clear to most respondents (78.1%); 7.7% found they were unclear. The majority of participants (86.8%) found GSK Vaccines' authorship questionnaire a suitable tool to assess eligibility for authorship as per the ICMJE criteria. However, only 68.5% felt that the outcome of the questionnaire is communicated appropriately and 58.3% felt well informed on changes in authorship. Nearly two-thirds (62.9%) of respondents felt that having a pharmaceutical company employee as lead author makes manuscript acceptance less likely. Access to relevant data was regarded as sufficient by 78.5% of respondents. Briefing meetings before publication start, publication steering committees and core writing teams were recognized as valuable publication practices. Professional medical writing support was seen as adding value to publication development by 87.7% of participants. Most respondents agreed that manuscript discussions should start early, with 81.7% stating that they were in favor of introducing a formalized 'author agreement' at the publication start. CONCLUSIONS: GSK Vaccines made changes to its publication practices to ensure improved transparency and better involvement of external authors. The results of this survey suggest that these changes have been effective to a large extent. They confirm the need for effective and timely communication, as well as transparent processes for authorship and decision-making during publication development. The identified gaps in GPP will help to guide further improvements to the company's policies on publication practices.

Galectin-1 is implicated in the protein kinase C epsilon/vimentin-controlled trafficking of integrin-beta1 in glioblastoma cells.

Cell motility and resistance to apoptosis characterize glioblastoma (GBM) growth and malignancy. In our current work we report that galectin-1, a homodimeric adhesion molecule and carbohydrate-binding protein with affinity for beta-galactosides, is linked with cell surface expression of integrin beta1 and the process of integrin trafficking. Using immunofluorescence, depletion of galectin-1 through both stable knockdown and transient-targeted small interfering RNA (siRNA) treatment induces an intracellular accumulation of integrin-beta1 coincident with a diminution of integrin-beta1 at points of cellular adhesion at the cell membrane. Galectin-1 depletion does not alter the gene expression level of integrin-beta1. Transient galectin-1 depletion effectuates as well the perinuclear accumulation of protein kinase C epsilon (PKCepsilon) and the intermediate filament vimentin, both of which have been shown to mediate integrin recycling in motile cells. Our results argue for the involvement of galectin-1 in the PKCepsilon/vimentin-controlled trafficking of integrin-beta1. The understanding of molecular mediators such as galectin-1 and the pathways through which they drive the cell invasion so descriptive of GBM is anticipated to reveal potential therapeutic targets that promote glioma malignancy.

High level of galectin-1 expression is a negative prognostic predictor of recurrence in laryngeal squamous cell carcinomas.

Monitoring of gene-expression profiles is assumed to refine tumor characterization of laryngeal squamous cell carcinomas (LSCCs) with a therapeutic perspective. This is especially expected for adhesion/growth-regulatory effectors such as galectins, a class of endogenous lectins. Using computer-assisted microscopy, we investigated the prognostic value contributed by the quantitative determination of the immunohistochemical levels of expression of galectin-1, -3 and -7 in a series of 62 LSCCs including 42 low- and 20 high-stage LSCCs. As galectin-1 may have a key role leading to a tumor escape from immune surveillance, we also investigated whether or not the level of galectin-1 expression correlated with lymphocyte infiltration in LSCCs. The immunohistochemical determination of expression of galectin-1 is of prognostic value in human squamous laryngeal cancers. LSCCs that display high levels of galectin-1 have worse prognoses than laryngeal cancers with low levels of galectin-1 expression. Elevation of galectin-1 levels in laryngeal cancers can contribute to the process of tumor immune escape by killing the activated T-cells and other protumoral activities such as promoting motility or activity of oncogenic H-Ras proteins. The quantitative determination of galectin-1 in LSCCs is an independent prognostic marker when opposed to TNM staging. It has the potential to identify patients unlikely to benefit from T-cell-mediated immunotherapy, although the definitive effector function from its pro- and antitumoral activity profile has not been delineated.

Galectins as modulators of tumor progression in head and neck squamous cell carcinomas.

Head and neck squamous cell carcinomas (HNSCCs) remain a significant cause of morbidity worldwide. Biological therapies able to induce and/or upregulate antitumor immune responses could represent a complementary approach to conventional treatments for patients with HNSCC because, despite advances in surgery, radiotherapy, and chemotherapy, the overall survival rates for these patients have not changed over recent decades. Galectins are involved in the control of cell proliferation, cell death, and cell migration and in the modulation of various functions of the immune system. In this context, galectin-1 is known to protect HNSCCs from the immune system. The present review details the involvement of galectins in HNSCC biology and suggests a number of approaches to reduce the levels of expression of galectin-1 in HNSCCs, with the aim of improving the efficiency of HNSCC immunotherapy.

Anti-galectin compounds as potential anti-cancer drugs.

Galectins form a family of carbohydrate-binding proteins defined by their affinity for beta-galactosides containing glycoconjugates. The carbohydrate recognition domain (CRD) is responsible for the specificity of galectins for saccharides. This binding may result in modulated cell proliferation, cell death and cell migration, three processes that are intimately involved in cancer initiation and progression. Galectins can also display protein-protein types of interactions with their binding partners. Certain galectins directly involved in cancer progression seem to be promising targets for the development of novel therapeutic strategies to combat cancer. Indeed, migrating cancer cells resistant to apoptosis still constitute the principal target for the cytotoxic drugs used to treat cancer patients. Reducing the levels of migration in apoptosis-resistant cancer cells can restore certain levels of sensitivity to apoptosis (and so to pro-apoptotic drugs) in restricted-migration cancer cells. Anti-galectin agents can restrict the levels of migration of several types of cancer cell and should therefore be used in association with cytotoxic drugs to combat metastatic cancer. We provide experimental proof in support of this concept. While the present review focuses on various experimental strategies to impair cancer progression by targeting certain types of galectins, it pays particular attention to glioblastomas, which constitute the ultimate level of malignancy in primary brain tumors. Glioblastomas form the most common type of malignant brain tumor in children and adults, and no glioblastoma patient has been cured to date.

Galectin-1: a small protein with major functions.

Galectins are a family of carbohydrate-binding proteins with an affinity for beta-galactosides. Galectin-1 (Gal-1) is differentially expressed by various normal and pathological tissues and appears to be functionally polyvalent, with a wide range of biological activity. The intracellular and extracellular activity of Gal-1 has been described. Evidence points to Gal-1 and its ligands as one of the master regulators of such immune responses as T-cell homeostasis and survival, T-cell immune disorders, inflammation and allergies as well as host-pathogen interactions. Gal-1 expression or overexpression in tumors and/or the tissue surrounding them must be considered as a sign of the malignant tumor progression that is often related to the long-range dissemination of tumoral cells (metastasis), to their dissemination into the surrounding normal tissue, and to tumor immune-escape. Gal-1 in its oxidized form plays a number of important roles in the regeneration of the central nervous system after injury. The targeted overexpression (or delivery) of Gal-1 should be considered as a method of choice for the treatment of some kinds of inflammation-related diseases, neurodegenerative pathologies and muscular dystrophies. In contrast, the targeted inhibition of Gal-1 expression is what should be developed for therapeutic applications against cancer progression. Gal-1 is thus a promising molecular target for the development of new and original therapeutic tools.

Present and potential future issues in glioblastoma treatment.

The treatment of glioblastomas requires a multidisciplinary approach that takes the presently incurable nature of the disease into consideration. Treatments are multimodal and include surgery, radiotherapy and chemotherapy. Current recommendations are that patients with glioblastomas should undergo maximum surgical resection, followed by concurrent radiation and chemotherapy with the novel alkylating drug temozolomide. This is then to be followed by additional adjuvant temozolomide for a period of up to 6 months. Major advances in surgical and imaging technologies used to treat glioblastoma patients are described. These technologies include magnetic resonance imaging and metabolic data that are helpful in the diagnosis and guiding of surgical resection. However, glioblastomas almost invariably recur near their initial sites. Disease progression usually occurs within 6 months and leads rapidly to death. A number of signaling pathways can be activated constitutively in migrating glioma cells, thus rendering these cells resistant to proapoptotic insults, such as conventional chemotherapies. Therefore, the molecular and cellular therapies and local drug delivery that could be used to complement conventional treatments are described, and some of the currently ongoing clinical trials are reviewed, with respect to these new approaches.

Galectin 7 (p53-induced gene 1): a new prognostic predictor of recurrence and survival in stage IV hypopharyngeal cancer.

BACKGROUND: Eighty percent of hypopharyngeal squamous cell carcinoma patients have advanced stages (III and IV) of the disease, and biological markers are required to predict high-risk head and neck squamous cell carcinoma patients in need of highly aggressive treatments after surgery to improve the survival rate. We analyzed the potential prognostic value of galectin 7 in a series of 81 stage IV hypopharyngeal SCCs because galectin 7 is an emerging marker involved in the epidermal development of pluristratified epithelia and in epidermal cell migration. METHODS: The immunohistochemical expression of galectin 7 was determined on a series of 81 stage IV hypopharyngeal SCCs and was compared with that of galectins 1 and 3. RESULTS: High levels of galectin 7 expression were associated with rapid recurrence rates and dismal prognoses in these 81 stage IV hypopharyngeal SCCs, a feature not observed with galectin 3 and one observed weakly, if at all, with galectin 1. CONCLUSIONS: These data suggest that the immunohistochemical determination of galectin 7 expression in the case of high-risk hypopharyngeal cancers is a meaningful tool to identify patients who should benefit from aggressive postsurgical adjuvant therapy after surgery, including not only radiotherapy, but also chemotherapy.

Galectin-1 knocking down in human U87 glioblastoma cells alters their gene expression pattern.

We have previously reported that (i) progression of malignancy in patients bearing astrocytic tumors correlates with increased tumor levels of galectin-1; (ii) in vitro addition of purified galectin-1 to U87 human glioblastoma cells enhances tumor cell motility; and (iii) conversely, knocking down galectin-1 expression in this cell line by stable transfection with antisense galectin-1 mRNA impairs motility and delays mortality after their intracranial grafting to nude mice. We here used cDNA microarray analysis to compare the effect on gene expression of stable transfection with antisense galectin-1 vector to mock-transfected and wild-type cells. Among the 631 spots probing genes potentially involved in cancer that were valid for analysis on all the arrays the expression of 86 genes was increased at least 2-fold. Confirmation of increased protein levels was provided by immunocytochemistry for p21waf/cip1, cullin-2, p53, ADAM-15, and MAP-2. Major differences in the expression patterns of ADAM-15 and the actin stress fiber organization were also observed. U87 cells stably deficient for galectin-1 expression were significantly less motile than control. We conclude that the stable inhibition of galectin-1 expression alters the expression of a number of genes that either directly or indirectly influence adhesion, motility and invasion of human glioblastoma cells.

Combined cimetidine and temozolomide, compared with temozolomide alone: significant increases in survival in nude mice bearing U373 human glioblastoma multiforme orthotopic xenografts.

OBJECT: Malignant gliomas consist of both heterogeneous proliferating and migrating cell subpopulations, with migrating glioma cells exhibiting less sensitivity to antiproliferative or proapoptotic drugs than proliferative cells. Therefore, the authors combined cimetidine, an antiinflammatory agent already proven to act against migrating epithelial cancer cells, with temozolomide to determine whether the combination induces antitumor activities in experimental orthotopic human gliomas compared with the effects of temozolomide alone. METHODS: Cimetidine added to temozolomide compared with temozolomide alone induced survival benefits in nude mice with U373 human glioblastoma multiforme (GBM) cells orthotopically xenografted in the brain. Computer-assisted phase-contrast microscopy analyses of 9L rat and U373 human GBM cells showed that cimetidine significantly decreased the migration levels of these tumor cells in vitro at concentrations at which tumor growth levels were not modified (as revealed on monotetrazolium colorimetric assay). Computer-assisted microscope analyses of neoglycoconjugate-based glycohistochemical staining profiles of 9L gliosarcomas grown in vivo revealed that cimetidine significantly decreased expression levels of endogenous receptors for fucose and, to a lesser extent, for N-acetyl-lactosamine moieties. Endogenous receptors of this specificity are known to play important roles in adhesion and migration processes of brain tumor cells. CONCLUSIONS: Cimetidine, acting as an antiadhesive and therefore an antimigratory agent for glioma cells, could be added in complement to the cytotoxic temozolomide compound to combat both migrating and proliferating cells in GBM.

v-Src accelerates spontaneous motility via phosphoinositide 3-kinase, phospholipase C and phospholipase D, but abrogates chemotaxis in Rat-1 and MDCK cells.

In Rat-1 fibroblasts, v-Src causes a profound remodelling of cortical actin cytoskeleton. This transformation includes membrane ruffling, a hallmark of the leading edge in migrating cells, and results from activation of phosphoinositide 3-kinase (PI 3-kinase), phospholipase C (PLC) and phospholipase D (PLD). We therefore reexamined whether motility is constitutively triggered by v-Src and studied whether this response is controlled by the same signalling pathway. The study was performed using Rat-1/tsLA29 and MDCK/tsLA31 cells, each harbouring a different thermosensitive v-Src kinase, active at 34 degrees C but inactivated at 40 degrees C. In both cell lines, overnight v-Src activation induced transformation and accelerated spontaneous motility by approximately twofold, as evidenced by wound-healing assay and by single-cell track, time-lapse recording in Dunn chambers. Inhibitors of PI 3-kinase, PLC and PLD selectively abrogated acceleration of motility by v-Src. Since mechanisms that co-ordinate spontaneous, as distinct from oriented, cell migration are separable, we further analysed in Dunn chambers chemotactic response of Rat-1/tsLA29 cells to PDGF and of MDCK/tsLA31 cells to EGF. In both cases, v-Src decreased the steady-state level of growth factor receptors at the cell surface twofold, and abrogated movement directionality at comparable level of occupancy as in non-transformed cells. The burst of pinocytosis in response to growth factors was also abolished by v-Src. Altogether, these results indicate that v-Src triggers motility in a PI 3-kinase-, PLC- and PLD-dependent manner, but abrogates directionality by suppressing polarised signalling downstream of growth factor receptors.

A model-based approach for automated in vitro cell tracking and chemotaxis analyses.

BACKGROUND: Chemotaxis may be studied in two main ways: 1) counting cells passing through an insert (e.g., using Boyden chambers), and 2) directly observing cell cultures (e.g., using Dunn chambers), both in response to stationary concentration gradients. This article promotes the use of Dunn chambers and in vitro cell-tracking, achieved by video microscopy coupled with automatic image analysis software, in order to extract quantitative and qualitative measurements characterizing the response of cells to a diffusible chemical agent. METHODS: Previously, we set up a videomicroscopy system coupled with image analysis software that was able to compute cell trajectories from in vitro cell cultures. In the present study, we are introducing a new software increasing the application field of this system to chemotaxis studies. This software is based on an adapted version of the active contour methodology, enabling each cell to be efficiently tracked for hours and resulting in detailed descriptions of individual cell trajectories. The major advantages of this method come from an improved robustness with respect to variability in cell morphologies between different cell lines and dynamical changes in cell shape during cell migration. Moreover, the software includes a very small number of parameters which do not require overly sensitive tuning. Finally, the running time of the software is very short, allowing improved possibilities in acquisition frequency and, consequently, improved descriptions of complex cell trajectories, i.e. trajectories including cell division and cell crossing. RESULTS: We validated this software on several artificial and real cell culture experiments in Dunn chambers also including comparisons with manual (human-controlled) analyses. CONCLUSIONS: We developed new software and data analysis tools for automated cell tracking which enable cell chemotaxis to be efficiently analyzed.

Up-regulation of galectin-3 and its ligands by Trypanosoma cruzi infection with modulation of adhesion and migration of murine dendritic cells.

The impact of a pathogen-induced inflammatory response on dendritic cells (DCs) and on their expression of galectin-3 (Gal-3) was studied on splenic DCs (sDCs) from Trypanosoma cruzi-infected mice. We determined the lectin expression and also presentation of ligands using the labeled galectin as probe. By reverse transcriptase polymerase chain reaction, western blot analysis, quantitative glycocytochemistry, and computer-assisted quantitative microscopy, we demonstrate that, in sDCs from infected mice, expression of Gal-3 and Gal-3-specific ligands were markedly up-regulated and adhesiveness was increased with Gal-3-coated substratum. Gal-3 expression was also enhanced in T. cruzi-infected D2SC-1 cells. To assess influence on migration, we had to work exclusively with D2SC-1 cells because sDCs rapidly lost their capacity to adhere to substratum. Migration of infected- and TCM-treated D2SC-1 cells were reduced when substratum was coated with Gal-3. Expression of Gal-3 by D2SC-1 was reduced when they were incubated with anti-Gal-3 antisense oligonucleotide without effect on cell invasion by the parasite. By using seven neoglycoconjugates, we probed the cellular capacity to specifically bind carbohydrate ligands. Similar to Gal-3, an up-regulation was noted with respect to sites specific for Man and alpha-GalNAc, respectively, revealing that infection-dependent changes are not confined to Gal-3-dependent parameters. Considered together, these data document for the first time that a parasitic infection can modulate both in vivo and in vitro the expression of Gal-3 and of ligands for this lectin in DCs with functional consequences on their capacities of adhesion and migration. These results suggest a new immunomodulatory property of T. cruzi.

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.

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.

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.

Gastrin significantly modifies the migratory abilities of experimental glioma cells.

Malignant astrocytic tumors are characterized by the pronounced and diffuse migration of tumor astrocytes into the brain parenchyma. The present study shows that gastrin is a brain neuropeptide that is able to significantly modulate astrocytic tumor migration at both invasion and motility levels. In the matter of invasion, gastrin severely reduces the in vitro invasive abilities of C6 rat glioma, 9L rat gliosarcoma, and U373 human glioma cells in a collagen matrix. In vitro, gastrin also markedly modifies the motility features in both C6 and U373 cells, at least partly through a decrease in the expression of the RhoA small GTPase, and so brings about some dramatic modifications to the organization in the actin cytoskeleton. The in vitro preincubation of C6 tumor cells with gastrin significantly increases the life spans of rats stereotactically implanted with these cells as compared with the survival periods of rats implanted with gastrin-untreated C6 cells. As suggested by our in vitro experiments, these effects, observed in vivo cannot relate to only the gastrin-induced decrease in tumor astrocyte migratory abilities. Indeed, gastrin also induces immunomodulatory effects, because we observed a marked gastrin-induced recruitment of lymphocytes into C6 gliomas and 9L gliosarcomas. These data all suggest that gastrin can act as an endogenous modulator of glioma progression.

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.

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.

Galectin-1 modulates human glioblastoma cell migration into the brain through modifications to the actin cytoskeleton and levels of expression of small GTPases.

We show that high-grade astrocytic tumors with high levels of galectin-1 expression are associated with dismal prognoses. The immunohistochemical analysis of galectin-1 expression of human U87 and U373 glioblastoma xenografts from the brains of nude mice revealed a higher level of galectin-1 expression in invasive areas rather than non-invasive areas of the xenografts. Nude mice intracranially grafted with U87 or U373 cells constitutively expressing low levels of galectin-1 (by stable transfection of an expression vector containing the antisense mRNA of galectin-1) had longer survival periods than those grafted with U87 or U373 cells expressing normal levels of galectin-1. Galectin-1 added to the culture media markedly and specifically increased cell motility levels in human neoplastic astrocytes. These effects are related to marked modifications in the organization of the actin cytoskeleton and the increase in small GTPase RhoA expression. All the data obtained indicate that galectin-1 enhances the migratory capabilities of tumor astrocytes and, therefore, their biological aggressiveness.