Manuel Deprez

Vascular endothelial growth factor expression correlates with matrix metalloproteinases MT1-MMP, MMP-2 and MMP-9 in human glioblastomas.

Vascular endothelial growth factor (VEGF) is the major endothelial mitogen in central nervous system neoplasms and it is expressed in 64–95% of glioblastomas (GBMs). Tumour cells are the main source of VEGF in GBMs whereas VEGF receptors (VEGFR‐1, its soluble form sVEGFR‐1, VEGFR‐2 and neuropilin‐1) are expressed predominantly by endothelial cells. Infiltrating tumour cells and newly‐formed capillaries progress through the extracellular matrix by local proteolysis involving matrix metalloproteinases (MMPs). Recent studies have shown that VEGF expression and bioavailability can be modulated by MMPs. We reported previously that the expression of MT1‐MMP in human breast cancer cells was associated with an enhanced VEGF expression. We used quantitative RT‐PCR, Western blot, gelatin zymography and immunohistochemistry to study the expression of VEGF, VEGFR‐1, VEGFR‐2, sVEGFR‐1, neuropilin‐1, MT1‐MMP, MMP‐2, MMP‐9 and TIMP‐2 in 20 human GBMs and 5 normal brains. The expression of these MMPs was markedly increased in most GBMs with excellent correlation between mRNA and protein levels; activated forms of MMP‐2 and MMP‐9 were present in 8/18 and 7/18 of GBMs. A majority of GBMs (17/20) also expressed high levels of VEGF, as previously reported, with strong correlation between VEGF and MT1‐MMP gene expression levels, and double immunostaining showed that VEGF and MT1‐MMP peptides co‐localize in tumour and endothelial cells. Our results suggest that the interplay between metalloproteinases and VEGF previously described in experimental tumours may also be operative in human GBMs. Because of its dual ability to activate MMP‐2 and to up‐regulate VEGF, MT1‐MMP might be of central importance in the growth of GBMs and represent an interesting target for anti‐cancer treatments.

Whole genome expression profiling of the medial and lateral substantia nigra in Parkinson’s disease

We have used brain tissue from clinically well-documented and neuropathologically confirmed cases of sporadic Parkinson’s disease to establish the transcriptomic expression profile of the medial and lateral substantia nigra. In addition, the superior frontal cortex was analyzed in a subset of the same cases. DNA oligonucleotide microarrays were employed, which provide whole human genome coverage. A total of 570 genes were found to be differentially regulated at a high level of significance. A large number of differentially regulated expressed sequence tags were also identified. Levels of mRNA sequences encoded by genes of key interest were validated by means of quantitative real-time polymerase chain reaction (PCR). Comparing three different normalization procedures, results based on the recently published GeneChip Robust Multi Array algorithm were found to be the most accurate predictor of real-time PCR results. Several new candidate genes which map to PARK loci are reported. In addition, the DNAJ family of chaperones is discussed in the context of Parkinson’s disease pathogenesis.

In vitro and in vivo activity of the nuclear factor-kappa B inhibitor sulfasalazine in human glioblastomas.

Glioblastomas, the most common primary brain cancers, respond poorly to current treatment modalities and carry a dismal prognosis. In this study, we demonstrated that the transcription factor nuclear factor (NF)-κB is constitutively activated in glioblastoma surgical samples, primary cultures, and cell lines and promotes their growth and survival. Sulfasalazine, an anti-inflammatory drug that specifically inhibits the activation of NF-κB, blocked the cell cycle and induced apoptosis in several glioblastoma cell lines and primary cultures, as did gene therapy with a vector encoding a super-repressor of NF-κB. In vivo, sulfasalazine also significantly inhibited the growth of experimental human glioblastomas in nude mice brains. Given the documented safety of sulfasalazine in humans, these results may lead the way to a new class of glioma treatment.

Clinicopathological features of eyelid skin tumors. A retrospective study of 5504 cases and review of literature.

Eyelid tumors are the most common neoplasm in daily ophthalmology practice and encompass a wide variety of benign and malignant tumors. In this retrospective study, we report the clinical and histological features of 5504 eyelid skin tumors diagnosed at the Laboratory of Ophthalmopathology of the Hôpital Ophtalmique Jules Gonin, Lausanne, Switzerland, between January 1989 and December 2007. Benign tumors largely predominated over malignant ones, representing 84% of cases in this series, and the 5 most frequent subtypes were squamous cell papilloma (26%), seborrheic keratosis (21%), melanocytic nevus (20%), hidrocystoma (8%), and xanthoma/xanthelasma (6%). Basal cell carcinoma was the most frequent malignant tumor (86%), followed by squamous cell carcinoma (7%) and sebaceous carcinoma (3%). For several tumor subtypes, there was a poor correlation between clinical and histological diagnosis, stressing the numerous pitfalls in the diagnosis of eyelid tumors. We further discuss our results with reference to previously published series.

Experimental anti-angiogenesis causes upregulation of genes associated with poor survival in glioblastoma

Vascular endothelial growth factor (VEGF) inhibitors are the most promising anti‐angiogenic agents used increasingly in the clinic. However, to be efficient, anti‐VEGF agents need to be associated with classic chemotherapy. Exploring gene regulation in tumor cells during anti‐angiogenesis might help to comprehend the molecular basis of response to treatment. To generate a defined anti‐angiogenic condition in vivo, we transfected human glioma cells with short‐interfering RNAs against VEGF‐A and implanted them on the chick chorio‐allantoic membrane. Gene regulation in avascular tumors was studied using human Affymetrix™ GeneChips. Potentially important genes were further studied in glioma patients. Despite strong VEGF inhibition, we observed recurrent formation of small, avascular tumors. CHI3L2, IL1B, PI3/elafin and CHI3L1, which encodes for YKL‐40, a putative prognosticator for various diseases, including cancer, were strongly up‐regulated in avascular glioma. In glioblastoma patients, these genes showed coregulation and their expression differed significantly from low‐grade glioma. Importantly, high levels of CHI3L1 (p = 0.036) and PI3/elafin mRNA (p = 0.0004) were significantly correlated with poor survival. Cox regression analysis further confirmed that PI3 and CHI3L1 levels are survival markers independent from patient age and sex. Elafin‐positive tumor cells were only found in glioblastoma, where they were clustered around necrotic areas. PI3/elafin is strongly induced by serum deprivation and hypoxia in U87 glioma cells in vitro. Our results indicate that anti‐angiogenesis in experimental glioma drives expression of critical genes which relate to disease aggressiveness in glioblastoma patients. In particular, CHI3L1 and PI3/elafin may be useful as new prognostic markers and new therapeutic targets.

Presence of Oestrogen Receptor Type Beta in Human Retina

BACKGROUND/AIMS Recent studies have demonstrated the existence of two oestrogen receptor subtypes α (ORα) and β (ORβ) with significant differences of expression among organs. Since important pathologies of human eye could be linked to hormonal status, the expression of ORβ in ocular posterior segment was sought. METHODS Immunohistochemical localisation of ORβ and ORα protein and detection of OR mRNAs by reverse transcription-polymerase chain reaction (RT-PCR) were performed in macular and extramacular regions of the retina and in the choroid on male and female donors eyes. RESULTS ORβ protein was localised in the ganglion cell layer and in the choroid. At the transcriptional level, mRNA for ORβ and for ORα were both present. Local differences in the expression level were observed, however, suggesting the possibility of variation in the ratio of ORαv ORβ. CONCLUSIONS The coexistence of two oestrogen receptor subtypes in the human ocular posterior segment raises acute questions about their potential physiological role, but offers a perspective for preferential targeting of a specific receptor subtype.

Transcriptome analysis reveals link between proteasomal and mitochondrial pathways in Parkinson’s disease

There is growing evidence that dysfunction of the mitochondrial respiratory chain and failure of the cellular protein degradation machinery, specifically the ubiquitin–proteasome system, play an important role in the pathogenesis of Parkinson’s disease. We now show that the corresponding pathways of these two systems are linked at the transcriptomic level in Parkinsonian substantia nigra. We examined gene expression in medial and lateral substantia nigra (SN) as well as in frontal cortex using whole genome DNA oligonucleotide microarrays. In this study, we use a hypothesis-driven approach in analysing microarray data to describe the expression of mitochondrial and ubiquitin–proteasomal system (UPS) genes in Parkinson’s disease (PD). Although a number of genes showed up-regulation, we found an overall decrease in expression affecting the majority of mitochondrial and UPS sequences. The down-regulated genes include genes that encode subunits of complex I and the Parkinson’s-disease-linked UCHL1. The observed changes in expression were very similar for both medial and lateral SN and also affected the PD cerebral cortex. As revealed by “gene shaving” clustering analysis, there was a very significant correlation between the transcriptomic profiles of both systems including in control brains. Therefore, the mitochondria and the proteasome form a higher-order gene regulatory network that is severely perturbed in Parkinson’s disease. Our quantitative results also suggest that Parkinson’s disease is a disease of more than one cell class, i.e. that it goes beyond the catecholaminergic neuron and involves glia as well.

Early termination of ISRCTN45828668, a phase 1/2 prospective, randomized study of Sulfasalazine for the treatment of progressing malignant gliomas in adults

BackgroundSulfasalazine, a NF-kappaB and x(c)-cystine/glutamate antiport inhibitor, has demonstrated a strong antitumoral potential in preclinical models of malignant gliomas. As it presents an excellent safety profile, we initiated a phase 1/2 clinical study of this anti-inflammatory drug for the treatment of recurrent WHO grade 3 and 4 astrocytic gliomas in adults.Methods10 patients with advanced recurrent anaplastic astrocytoma (n = 2) or glioblastoma (n = 8) aged 32-62 years were recruited prior to the planned interim analysis of the study. Subjects were randomly assigned to daily doses of 1.5, 3, 4.5, or 6 grams of oral sulfasalazine, and treated until clinical or radiological evidence of disease progression or the development of serious or unbearable side effects. Primary endpoints were the evaluation of toxicities according to the CTCAE v.3.0, and the observation of radiological tumor responses based on MacDonald criteria.ResultsNo clinical response was observed. One tumor remained stable for 2 months with sulfasalazine treatment, at the lowest daily dose of the drug. The median progression-free survival was 32 days. Side effects were common, as all patients developed grade 1-3 adverse events (mean: 7.2/patient), four patients developed grade 4 toxicity. Two patients died while on treatment or shortly after its discontinuation.ConclusionAlthough the proper influence of sulfasalazine treatment on patient outcome was difficult to ascertain in these debilitated patients with a large tumor burden (median KPS = 50), ISRCTN45828668 was terminated after its interim analysis. This study urges to exert cautiousness in future trials of Sulfasalazine for the treatment of malignant gliomas.Trial RegistrationCurrent Controlled Trials ISRCTN45828668

Tricho-hepato-enteric syndrome : Further delineation of a distinct syndrome with neonatal hemochromatosis phenotype, intractable diarrhea, and hair anomalies

We report on two sibs with syndromal congenital iron storage disease. Prenatal symptoms were IUGR, hydramnios, and placental hyperplasia. Clinical anomalies included hypertelorism and sparse, thin, curly hair (trichomalacia). Clinical course was marked by intractable diarrhoea, with normal histological and enzymological studies, cholestatic jaundice, hepatomegaly appearing after 30 days, and progressive liver failure, leading to death after a few months. The only metabolic anomaly was progressive hypermethioninemia. Pathologic examination of both children showed a similar pattern of multivisceral iron deposit compatible with a diagnosis of neonatal hemochromatosis: extensive liver fibrosis or cirrhosis with nodular regeneration, cholestasis, ductular proliferation, and hepatic, pituitary, thyroidal, adrenal, and pancreatic iron deposition. The unusual course for neonatal hemochromatosis in both sibs combined with concordant extrahepatic anomalies suggest that they could have a specific iron storage syndrome with possible autosomal recessive inheritance, probably similar to the sibship reported by Stanckler et al. [Arch Dis Child, 57:212-216, 1982].

Macrophage migration inhibitory factor (MIF) expression in human glioblastomas correlates with vascular endothelial growth factor (VEGF) expression

Macrophage migration inhibitory factor (MIF) is a peptide released upon hypothalamo–pituitary stimulation that acts as a potent endogenous antagonist of the glucocorticoid inhibition of acute inflammatory response and subsequent antigen‐specific response. MIF also sustains tumour growth as it promotes angiogenesis, overcomes p53‐mediated cell growth arrest and inhibits tumour‐specific immune responses. Using quantitative reverse transcriptase polymerase chain reaction (RT‐PCR) and immunohistochemistry, we studied MIF expression in 35 human glioblastomas and two normal brains. We compared these results with the expression of vascular endothelial growth factor (VEGF), the most potent angiogenic factor in glioblastomas. We detected MIF in normal cortical neurons and glial cells. All glioblastomas were positive for MIF mRNA with expression levels similar to or higher than those of normal brain. MIF immunoreactivity was seen mainly in tumour cells and less frequently in hyperplastic endothelial cells. The expressions of MIF and VEGF mRNA were strongly correlated (P < 0.0001). Our results demonstrate the expression of MIF in human glioblastomas, and indicate a close relationship with VEGF expression. This is of particular interest given the potential modulation of MIF by glucocorticosteroids.