Randomized phase II trial comparing axitinib with the combination of axitinib and lomustine in patients with recurrent glioblastoma.

Axitinib is a small molecule tyrosine kinase inhibitor with high affinity and specificity for the family of vascular endothelial growth factor receptors. It has previously demonstrated anti-tumor activity in a small cohort of patients with recurrent glioblastoma (rGB). We conducted a non-comparative randomized phase II clinical trial investigating axitinib monotherapy versus axitinib plus lomustine (LOM) in patients with rGB. Primary endpoint was 6 month progression-free survival (6mPFS). Patients who progressed on axitinib-monotherapy were allowed to cross-over. Between August 2011 and July 2015, 79 patients were randomized and initiated axitinib monotherapy (n = 50; AXI) or axitinib plus lomustine (n = 29; AXILOM). Median age was 55y [range 18-80], 50M/28F. Baseline characteristics were well balanced between study arms. Nineteen patients in the AXI-arm crossed-over at the time of progression. Treatment was generally well tolerated. AXILOM patients were at higher risk for grade 3/4 neutropenia (0 vs. 21%) and thrombocytopenia (4 vs. 29%). Best Overall Response Rate (BORR) in the AXI-arm was 28 vs. 38% in the AXILOM-arm. 6mPFS was 26% (95% CI 14-38) versus 17% (95% CI 2-32) for patients treated in the AXI versus AXILOM-arms, respectively. Median overall survival was 29 weeks (95% CI 20-38) in the AXI-arm and 27.4 weeks (95% CI 18.4-36.5) in the AXILOM-arm. MGMT-promoter hypermethylation and steroid treatment at baseline correlated significantly with PFS and OS. We conclude from these results that axitinib improves response rate and progression-free survival in patients with rGB compared to historical controls. There is no indication that upfront combination of axitinib with LOM improves results (European Clinical Trials Database (EudraCT) Study Number: 2011-000900-16).

Randomized phase II study of axitinib versus physicians best alternative choice of therapy in patients with recurrent glioblastoma.

We conducted a randomized, non-comparative, multi center, phase II clinical trial in order to investigate the efficacy of axitinib, an oral small molecule tyrosine kinase inhibitor with high affinity and specificity for the vascular endothelial growth factor receptors, in patients with recurrent glioblastoma following prior treatment with radiation and temozolomide. Forty-four patients were randomly assigned to receive treatment with axitinib (5 mg BID starting dose; N = 22) or "physicians best alternative choice of therapy" that consisted of bevacizumab (N = 20) or lomustine (N = 2). Six-month progression-free survival served as the primary endpoint. The estimated 6-month progression-free survival rate was 34 % (95 % CI 14-54) for patients treated with axitinib and 28 % (95 % CI 8-48) with best alternative treatment; median overall survival was 29 and 17 weeks, respectively. Objective responses according to RANO criteria were documented in 28 % of patients treated with axitinib and 23 % of patients treated with best alternative therapy. A decrease in maximal uptake of 18F-fluoro-ethyL-tyrosine (18F-FET) by the glioblastoma on PET imaging was documented in 85 % of patients at the time of response on axitinib. Corticosteroid treatment could be stopped in four and tapered in seven out of the 15 patients who were treated with steroids at baseline in the axitinib cohort. Most frequent axitinib related grade ≥3 adverse events consisted of fatigue (9 %), diarrhea (9 %), and oral hyperesthesia (4.5 %). We conclude that axitinib has single-agent clinical activity and a manageable toxicity profile in patients with recurrent glioblastoma.

[How molecular biology can improve the clinical diagnosis of gliomas?] / Comment la biologie moléculaire améliore le diagnostic clinique des gliomes?

Gliomas are the most common primary brain tumors and include different diagnoses associated with a different prognosis. Histology remains the gold standard for the diagnosis of these tumors. However, pathologists may encounter diagnostic difficulties due to tumor heterogeneity or to the small size of the samples. Recently, major advances in discovery of molecular alterations of these cancers have led to the development of new molecular markers, some with a diagnostic role, others with a prognostic impact and / or predictive of therapeutic response. The testing of different molecular alterations such as 1p / 19q codeletion, mutations of IDH genes, p16 deletion, EGFR amplification or MGMT promoter methylation has been included in the daily practice in order to confirm the diagnosis, assess the patient prognosis and guide treatment choices.

Les gliomes représentent les tumeurs cérébrales primitives les plus fréquentes et regroupent différentes entités au pronostic très différent. L'examen anatomopathologique est le gold standard pour le diagnostic de ces tumeurs. Cependant, les pathologistes peuvent rencontrer des difficultés diagnostiques dues, entre autres, à l'hétérogénéité tumorale ou à la petite taille des prélèvements. Nous avons assisté, ces dernières années, à des avancées majeures dans la découverte des altérations moléculaires de ces cancers, ce qui a mené au développement de nouveaux marqueurs moléculaires, certains avec un rôle diagnostique, d'autres avec un impact pronostique et/ou prédictif de la réponse thérapeutique. Dans la pratique quotidienne, il est donc devenu utile de tester la présence de différentes altérations moléculaires telles que la codélétion 1p/19q, les mutations des gènes IDH, la délétion du gène CDKN2A/p16, l'amplification du gène EGFR ou la méthylation du promoteur du gène MGMT, afin de confirmer le diagnostic, d'évaluer le pronostic des patients ainsi que d'orienter les choix thérapeutiques.

[Next generation sequencing]. / Une nouvelle technologie pour améliorer le diagnostic des cancers thyroïdiens.

Fine needle aspiration is the gold standard method to differentiate benign thyroid nodules from malignant. However, for 15 to 30% of the cases the cytological diagnosis is indeterminate, leading to surgery. Integration of new molecular markers is opening new perspectives in order to increase the diagnostic precision of thyroid nodules with an indeterminate cytology.

La méthode diagnostique de référence pour différencier les nodules thyroïdiens bénins des nodules malins est la ponction écho-guidée à l'aiguille fine. Cependant dans 15 à 30 % des cas le diagnostic cytologique est indéterminé, menant à une intervention chirurgicale. L'intégration de nouveaux marqueurs moléculaires nous ouvrent de nouvelles perspectives pour augmenter la précision diagnostique des nodules thyroïdiens de diagnostic cytologique indéterminé.

IGF-IR: a new prognostic biomarker for human glioblastoma.

BACKGROUND: Glioblastomas (GBMs) are the most common malignant primary brain tumours in adults and are refractory to conventional therapy, including surgical resection, radiotherapy and chemotherapy. The insulin-like growth factor (IGF) system is a complex network that includes ligands (IGFI and IGFII), receptors (IGF-IR and IGF-IIR) and high-affinity binding proteins (IGFBP-1 to IGFBP-6). Many studies have reported a role for the IGF system in the regulation of tumour cell biology. However, the role of this system remains unclear in GBMs. METHODS: We investigate the prognostic value of both the IGF ligands' and receptors' expression in a cohort of human GBMs. Tissue microarray and image analysis were conducted to quantitatively analyse the immunohistochemical expression of these proteins in 218 human GBMs. RESULTS: Both IGF-IR and IGF-IIR were overexpressed in GBMs compared with normal brain (P<10(-4) and P=0.002, respectively). Moreover, with regard to standard clinical factors, IGF-IR positivity was identified as an independent prognostic factor associated with shorter survival (P=0.016) and was associated with a less favourable response to temozolomide. CONCLUSIONS: This study suggests that IGF-IR could be an interesting target for GBM therapy.

Microsatellite instable vs stable colon carcinomas: analysis of tumour heterogeneity, inflammation and angiogenesis.

BACKGROUND: Microsatellite instability (MSI) accounts for 15% of all colorectal tumours. Several specific clinicopathologicals (e.g., preference for the proximal colon over the distal colon, improved prognosis and altered response to chemotherapeutics) are described for this subset of tumours. This study aimed to analyse morphological, inflammatory and angiogenic features of MSI vs microsatellite stable (MSS) tumours. METHODS: Twenty-seven MSS and 29 MSI, TNM stage matched, colorectal tumours were selected from the archive of the Department of Pathology, UZ Leuven. Morphology was analysed on haematoxylin-eosin sections. Immunohistochemistry for CD3, CD4, CD8, CD20 and CD68 was used to map tumour infiltration in both a digital and traditional microscope-based manner for all distinct morphological components of the tumour. CD31 immunostains were performed to assess angiogenesis. RESULTS: Morphological tumour heterogeneity was a marked feature of MSI tumours, occurring in 53% of the cases as compared with 11% of the MSS tumours (P<0.001). Digital immune quantification showed an increased number of tumour-infiltrating cytotoxic T-lymphocytes (CD8+) in MSI compared with MSS tumours for both the tumour (P=0.02) and peritumoural area (P=0.03). Traditional microscope-based quantification confirmed these results (P<0.001 for both) and, in addition, revealed large numbers of CD68+ macrophages in the peritumoural area of MSI cancers (P=0.001). Moreover, traditional microscope-based analysis was able to distinguish between lymphocytes directly infiltrating the tumoural glands (intra-epithelial) and those infiltrating only the neoplastic stroma around the glands (intratumoural). Quantification showed high numbers of intra-epithelial CD3+, CD4+, CD8+, CD20+ and CD68+ cells in MSI compared with MSS cancers (P<0.001, P=0.01, P<0.001, P<0.001 and P=0.006, respectively). Higher microvessel density (MVD) was observed in MSI tumours compared with their MSS counterpart. CONCLUSIONS: Mixed morphology, reflecting tumour heterogeneity, is an important feature of MSI tumours and may have both diagnostic and therapeutic impact. The inflammatory reaction also presented with significant differences in MSI vs MSS colorectal tumours. MSI cancers showed mainly infiltration by cytotoxic T-cells in both the tumour and the close border around the tumour, as well as increased intra-epithelial infiltration in contrast to MSS tumours. The type of immune cell and the compartment it resides in (intratumoural or intra-epithelial) depend both on MSI status and morphology. Finally, MSI tumours showed a higher angiogenic capacity represented by an increased MVD, hinting for possible therapeutic consequences.

Epithelial expression of FHL2 is negatively associated with metastasis-free and overall survival in colorectal cancer.

BACKGROUND: Four-and-a-half LIM domains protein 2 (FHL2) is a component of the focal adhesion structures and has been suggested to have a role in cancer progression. It has been shown to be overexpressed in the colorectal cancer (CRC). METHODS: Here, we examined a possible prognostic value of FHL2 in CRC. Immunohistochemistry for FHL2 was performed on 296 CRCs without distant metastases at the time of surgery. Staining in the epithelial compartment was quantitatively evaluated using image analysis, and results were related to clinical variables. Antibody specificity was tested using small-interfering RNA transfection in hTERT-immortalised myofibroblasts. RESULTS: Varying degrees of cytoplasmic FHL2 expression by neoplastic epithelial cells were detectable in all cases. Higher FHL2 expression in the epithelial compartment was an independent adverse prognostic factor. Multivariate Cox analysis shows that expression in the tumour invasion front (P<0.001) as well as in the centre of the tumour (P<0.001) was associated with metachronous metastases independently of the clinicopathological variables; expression in the tumour invasion front was also associated with overall survival independently of the clinicopathological variables (P<0.01). CONCLUSION: Higher FHL2 expression is involved in CRC progression and correlates with the development of metachronous metastases and overall survival, suggesting that FHL2 is an independent adverse prognostic indicator for CRC.

Molecular changes in pancreatic cancer: implications for molecular targeting therapy.

Pancreatic ductal adenocarcinoma has a high mortality rate, which is generally related to the initial diagnosis coming at late stage disease combined with a lack of effective treatment options. Gemcitabine has been the most commonly used drug over the past decade and is still the cornerstone of therapy in adjuvant and metastatic settings. Intrinsic or acquired resistance of tumours to gemcitabine is, however, a major clinical problem. New therapeutic strategies are urgently needed whereas we also need to identify new prognostic and predictive biomarkers. This article focuses on gemcitabine resistance, on the role of chemokines and chemokine receptors in pancreatic carcinoma initiation and progression, and on stellate cells as partners in crime with neoplastic epithelial cells.

Expression of endoplasmic reticulum stress markers in the islets of patients with type 1 diabetes.

AIMS/HYPOTHESIS: Endoplasmic reticulum (ER) stress may play a role in cytokine-mediated beta cell death in type 1 diabetes, but it remains controversial whether ER stress markers are present in islets from type 1 diabetic individuals. Therefore, we evaluated by immunostaining the expression of markers of the three main branches of the ER stress response in islets from 13 individuals with and 15 controls without type 1 diabetes (eight adults and seven children). METHODS: Antibodies against the ER stress markers C/EBP homologous protein (CHOP), immunoglobulin heavy chain (BIP) and X-box binding protein 1 (XBP-1) were validated using HeLa cells treated with the ER stressor thapsigargin. These antibodies were then used to stain serial sections of paraffin-embedded pancreas from type 1 diabetic and non-diabetic individuals; samples were also immunostained for CD45, insulin and glucagon. Immunostaining intensities of the ER stress markers were quantified using a software-based, unbiased quantitative approach. RESULTS: Islets from individuals with type 1 diabetes showed increased levels of CHOP and, at least for insulitis-positive and beta cell-containing islets, BIP. XBP-1 expression was not, however, increased. CONCLUSIONS/INTERPRETATION: Islet cells from individuals with type 1 diabetes display a partial ER stress response, with evidence of the induction of some, but not all, components of the unfolded protein response.

An observational study of the first experience with bevacizumab for the treatment of patients with recurrent high-grade glioma in two belgian university hospitals.

Background. Bevacizumab (BEV), a humanized immunoglobulin G1 monoclonal antibody that inhibits VEGF has demonstrated activity against recurrent high-grade gliomas (HGG) in phase II clinical trials. Patients and Methods. Data were collected from patients with recurrent HGG who initiated treatment with BEV outside a clinical trial protocol at two Belgian university hospitals. Results. 19 patients (11 M/8 F) were administered a total of 138 cycles of BEV (median 4, range 1-31). Tumor response assessment by MRI was available for 15 patients; 2 complete responses and 3 partial responses for an objective response rate of 26% for the intent to treat population were observed on gadolinium-enhanced T1-weighted images; significant regressions on T2/FLAIR were documented in 10 out of 15 patients (67%). A reduced uptake on PET was documented in 3 out of 4 evaluable patients. The six-month progression-free survival was 21% (95% CI 2.7-39.5). Two patients had an ongoing tumor response and remained free from progression after 12 months of BEV treatment. Conclusions. The activity and tolerability of BEV were comparable to results from previous prospective phase II trials. Reduced uptake on PET suggests a metabolic response in addition to an antiangiogenic effect in some cases with favorable clinical outcome.

Contribution of CXCR4 and SMAD4 in predicting disease progression pattern and benefit from adjuvant chemotherapy in resected pancreatic adenocarcinoma.

BACKGROUND: Prognosis of patients with pancreatic adenocarcinoma is poor. Many prognostic biomarkers have been tested, but most studies included heterogeneous patients. We aimed to investigate the prognostic and/or predictive values of four relevant biomarkers in a multicentric cohort of patients. PATIENTS AND METHODS: A total of 471 patients who had resected pancreatic adenocarcinoma were included. Using tissue microarray, we assessed the relationship of biomarker expressions with the overall survival: Smad4, type II TGF-ß receptor, CXCR4, and LKB1. RESULTS: High CXCR4 expression was found to be the only independent negative prognostic biomarker [hazard ratio (HR) = 1.74; P < 0.0001]. In addition, it was significantly associated with a distant relapse pattern (HR = 2.19; P < 0.0001) and was the strongest prognostic factor compared with clinicopathological factors. In patients who did not received adjuvant treatment, there was a trend toward decrease in the overall survival for negative Smad4 expression. Loss of Smad4 expression was not correlated with recurrence pattern but was shown to be predictive for adjuvant chemotherapy (CT) benefit (HR = 0.59; P = 0.002). CONCLUSIONS: CXCR4 is a strong independent prognostic biomarker associated with distant metastatic recurrence and appears as an attractive target to be evaluated in pancreatic adenocarcinoma. Negative SMAD4 expression should be considered as a potential predictor of adjuvant CT benefit.

Clinicopathological significance of indoleamine 2,3-dioxygenase 1 expression in colorectal cancer.

BACKGROUND: Indoleamine 2,3-dioxygenase 1 (IDO1) is a tryptophan-catabolising enzyme that induces immune tolerance by modulating T-cell responses. Carcinomas may create an immunosuppressive state via IDO1 expression. Here we examined a possible contribution of IDO1 on this phenomenon and investigated whether IDO1 has prognostic value in colorectal cancer (CRC). METHODS: IDO1 expression was investigated by quantitative PCR and western blotting in three colon cancer cell lines, in basal state and after interferon (IFN)-γ stimulation. Semi-quantitative immunohistochemistry was used to evaluate IDO1 expression in 265 pT1-4N0-2Mx-staged CRCs. Results were related to clinical variables and correlated with amounts of CD3(+) and CD8(+) T lymphocytes, which were quantitatively evaluated using image analysis. RESULTS: In vitro expression of IDO1 depended on IFN-γ stimulation. Higher IDO1 expression at the tumour invasion front was an independent adverse prognostic factor in pT1-4N1Mx-staged CRC. It was associated with overall survival (P=0.001) and with metachronous metastases (P=0.018). IDO1 expression was not associated with the presence of CD3(+) or CD8(+) T lymphocytes. CONCLUSION: Higher IDO1 expression at the tumour invasion front is involved in CRC progression and correlates with impaired clinical outcome, suggesting that IDO1 is an independent prognostic indicator for CRC.

Primary bilateral pontine demyelination in a cat with similarity to central pontine myelinolysis.

An adult cat was presented with the history of 3 months' weight loss and more recent loss of balance and ataxia. An abdominal mass was palpable; results of neurologic examination suggested a brainstem disorder. The owners elected euthanasia. Postmortem findings included suppurative jejunal lymphadenitis and bilateral demyelination in the ventral pons with sparing of axons and neuronal soma. The location and character of the lesion mimicked those of human central pontine myelinolysis, an iatrogenic condition that may follow rapid correction of hyponatremia or develop spontaneously in patients with malnutrition or energy deprivation. In this cat, the poor nutritional state may have contributed to the development of this novel pontine lesion.

[A case of von Hippel-Lindau disease diagnosed at the autopsy]. / A propos d'un cas de maladie de von Hippel-Lindau diagnostiqué lors de l'autopsie.

A 46-year-old woman presents with walk instability. A diagnosis of cerebellar hemangioblastoma is made on MRI and neurosurgical excision was performed. In the postoperative course, the patient died of a bulbar cerebral stroke with respiratory distress. At the autopsy, the finding of a bilateral renal clear cell carcinoma in addition to the cerebellar hemangioblastoma allows for the diagnosis of von Hippel-Lindau disease. It is an inherited, autosomal dominant syndrome charaterized by a VHL gene mutation. Affected individuals are at risk of developing various benign and malignant tumors of multiple organs, reviewed in this article. Despite a decrease of number of necropsy, this case as the review of literature demonstrates clinical importance of autopsy.

A genomic-based approach identifies FXYD domain containing ion transport regulator 2 (FXYD2)gammaa as a pancreatic beta cell-specific biomarker.

AIMS/HYPOTHESIS: Non-invasive imaging of the pancreatic beta cell mass (BCM) requires the identification of novel and specific beta cell biomarkers. We have developed a systems biology approach to the identification of promising beta cell markers. METHODS: We followed a functional genomics strategy based on massive parallel signal sequencing (MPSS) and microarray data obtained in human islets, purified primary rat beta cells, non-beta cells and INS-1E cells to identify promising beta cell markers. Candidate biomarkers were validated and screened using established human and macaque (Macacus cynomolgus) tissue microarrays. RESULTS: After a series of filtering steps, 12 beta cell-specific membrane proteins were identified. For four of the proteins we selected or produced antibodies targeting specifically the human proteins and their splice variants; all four candidates were confirmed as islet-specific in human pancreas. Two splice variants of FXYD domain containing ion transport regulator 2 (FXYD2), a regulating subunit of the Na(+)-K(+)-ATPase, were identified as preferentially present in human pancreatic islets. The presence of FXYD2gammaa was restricted to pancreatic islets and selectively detected in pancreatic beta cells. Analysis of human fetal pancreas samples showed the presence of FXYD2gammaa at an early stage (15 weeks). Histological examination of pancreatic sections from individuals with type 1 diabetes or sections from pancreases of streptozotocin-treated Macacus cynomolgus monkeys indicated a close correlation between loss of FXYD2gammaa and loss of insulin-positive cells. CONCLUSIONS/INTERPRETATION: We propose human FXYD2gammaa as a novel beta cell-specific biomarker.

High expression of CXCR4 may predict poor survival in resected pancreatic adenocarcinoma.

Chemokines and their receptors are involved in tumourigenicity and clinicopathological significance of chemokines receptor expression in pancreatic adenocarcinoma (PA) is not fully understood. This study was conducted to determine patients' outcome according to the expressions of CXCR4, CXCR7 and HIF-1alpha after resection of PA. Immunohistochemistry for CXCR4, CXCR7 and HIF-1alpha expressions as well as cell proliferative index (Ki-67) was conducted in 71 resected (R0) PA and their 48 related lymph nodes (LN) using tissue microarray. CXCR4 and CXCR7 expressions were positively correlated to HIF-1alpha suggesting a potential role of HIF-1alpha in CXCR4 and CXCR7 transcription activation. Patients with CXCR4(high) tumour expression had shorter OS than those with low expression (median survival: 9.7 vs 43.2 months, P=0.0006), a higher risk of LN metastases and liver recurrence. In multivariate analysis, high CXCR4 expression, LN metastases and poorly differentiated tumour are independent negative prognosis factors. In a combining analysis, patients with a CXCR7(high)/CXCR4(high) [corrected] tumour had a significantly shorter DFS and OS than patients with a CXCR4(low)/CXCR7(low) [corrected] tumour. CXCR4 in resected PA may represent a valuable prognostic factor as well as an attractive target for therapeutic purpose.

The galectin family and digestive disease.

The soluble-type lectins or galectins constitute a family of proteins defined by shared consensus amino acid sequence and affinity for beta-galactose-containing oligosaccharides. These molecules are widely distributed in the animal kingdom; to date, 15 mammalian galectins have been described but more are likely to be discovered. These proteins are involved in many biological processes including cell-cell and cell-matrix adhesion, growth regulation, signaling, and cytokine secretion. Over the last decade, a vast amount of reports has shown the importance of several galectins in the development and progression of malignancies in the digestive tract, mainly colorectal cancers. More recent data indicate that some of these molecules are also involved in inflammatory bowel diseases. This review focuses on the current knowledge of galectin expression and putative functions in the oesophagus, stomach, small intestine, and colon. It also highlights that the rapid accumulation of research data promises future scenarios in which individual members of the galectin family and/or their ligands will be used as diagnostic and therapeutic modalities for neoplastic as well as inflammatory disorders. However, the concretization of these potential modalities requires substantial improvements in terms of standardization of galectin expression evaluation together with prospective validation of the present data.

Apparent diffusion coefficient and cerebral blood volume in brain gliomas: relation to tumor cell density and tumor microvessel density based on stereotactic biopsies.

BACKGROUND AND PURPOSE: MR imaging-based apparent diffusion coefficient (ADC) and regional cerebral blood volume (rCBV) measurements have been related respectively to both cell and microvessel density in brain tumors. However, because of the high degree of heterogeneity in gliomas, a direct correlation between these MR imaging-based measurements and histopathologic features is required. The purpose of this study was to correlate regionally ADC and rCBV values with both cell and microvessel density in gliomas, by using coregistered MR imaging and stereotactic biopsies. MATERIALS AND METHODS: Eighteen patients (9 men, 9 women; age range, 19-78 years) with gliomas underwent diffusion-weighted and dynamic susceptibility contrast-enhanced MR imaging before biopsy. Eighty-one biopsy samples were obtained and categorized as peritumoral, infiltrated tissue, or bulk tumor, with quantification of cell and microvessel density. ADC and rCBV values were measured at biopsy sites and were normalized to contralateral white matter on corresponding maps coregistered with a 3D MR imaging dataset. ADC and rCBV ratios were compared with quantitative histologic features by using the Spearman correlation test. RESULTS: The highest correlations were found within bulk tumor samples between rCBV and cell density (r=0.57, P < .001) and rCBV and microvessel density (r=0.46, P < .01). An inverse correlation was found between ADC and microvessel density within bulk tumor (r=-0.36, P < .05), whereas no significant correlation was found between ADC and cell density. CONCLUSION: rCBV regionally correlates with both cell and microvessel density within gliomas, whereas no regional correlation was found between ADC and cell density.

Aristolochic acid induces proximal tubule apoptosis and epithelial to mesenchymal transformation.

Aristolochic acid contamination in herbal remedies leads to interstitial fibrosis, tubular atrophy, and renal failure in humans. To study the cellular mechanisms contributing to the pathophysiology of this renal disease, we studied Wistar rats treated with aristolochic acid and measured tubular and interstitial cell proliferation, epithelial/mesenchymal cell marker expression, tubular membrane integrity, myofibroblast accumulation, oxidative stress, mitochondrial damage, tubular apoptosis, and fibrosis. Oxidative stress, a loss of cadherin concomitant with vimentin expression, basement membrane denudation with active caspase-3 expression, and mitochondrial injury within tubular cells were evident within 5 days of administration of the toxin. During the chronic phase, interstitial mesenchymal cells accumulated in areas of collagen deposits. Impaired regeneration and apoptosis of proximal tubular cells resulted in tubule atrophy with a near absence of dedifferentiated cell transmembrane migration. We suggest that resident fibroblast activation plays a critical role in the process of renal fibrosis during aristolochic acid toxicity.

Tenascin-C expression relates to clinicopathological features in pilocytic and diffuse astrocytomas.

AIMS: Tenascin-C (TN-C) is an extracellular matrix brain glycoprotein for which conflicting in vitro and in vivo results are reported in the literature dealing with its involvement in astrocytoma aggressiveness, in particular astrocytoma invasion. In view of these conflicting results and the lack of data available on low-grade astrocytomas, the present study focuses on pilocytic World Health Organization (WHO) grade I, and diffuse WHO grade II astrocytomas, that is, two histological entities associated with very different invasive abilities. METHODS: Using real-time reverse transcription polymerase chain reaction and immunohistochemistry, we analysed the TN-C expression in normal brain tissue as well as in a series of 54 pilocytic and 53 grade II astrocytomas. CONCLUSIONS: Our data on normal brain showed that while TN-C is largely expressed in supratentorial white matter, it was largely absent in infratentorial white matter. Paralleling these observations, we showed that TN-C expression in low-grade astrocytomas similarly varies according to tumour site. Cox regression analysis evidenced that TN-C provided an independent prognostic value which is enhanced in the case of grade II astrocytomas for which positive TN-C expression is associated with a higher risk of recurrence. We also analysed TN-C expression specifically in vascular areas of low-grade astrocytomas without demonstrating any prognostic value for this additional feature. RESULTS: Similarly to normal brain, low-grade astrocytomas exhibit variations in TN-C expression with site, and this expression is associated with an independent prognostic value in terms of recurrence.