Pediatric pheochromocytoma in association with Von Hippel-Lindau disease: Focus on screening strategies.

INTRODUCTION: Von Hippel-Lindau disease (VHL) is a syndrome of familial predisposition to the development of malignant and benign tumours, due to mutations in the VHL tumour suppressor gene. Pheochromocytoma is a tumour that develops in the adrenal gland, rare in pediatric age, and may be associated with genetic abnormalities including mutations in the VHL gene. Systematic screening of pheochromocytoma in children carrying a VHL mutation has been proposed. However, some VHL patients who have been screened may develop symptoms associated with pheochromocytoma despite screening. Here, we report on such a case. CLINICAL CASE: A 13-year-old boy, known to be a carrier of a mutation of the VHL gene, undergoing annual screening, was admitted to our hospital for clinical symptoms related to a right adrenal pheochromocytoma discovered on abdominal imaging. After hemodynamic stabilisation, the pheochromocytoma was surgically resected. Histology confirmed the diagnosis of pheochromocytoma. The postoperative care was simple. The event-free period is currently 2 years. DISCUSSION: The present case has led us to reflect on the French and international screening strategies for pheochromocytoma in children carrying a mutation of the VHL gene. Between 2013 and 2018, six different recommendations were proposed for pheochromocytoma screening in secondary prevention for children with a VHL mutation, with variability regarding the age of onset and complementary examinations to be carried out. Despite the existence of these recommendations, our case demonstrates that a pheochromocytoma can develop by escaping well-performed screening. The role of early abdominal imaging should be redefined to improve the efficiency of screening. CONCLUSION: The discovery of a pheochromocytoma in a child must be systematically investigated for an underlying genetic cause. In the particular case of children carrying a mutation of the VHL gene, annual abdominal imaging should be included in the pheochromocytoma screening protocol from the age of 5 years.

[Type 1 neurofibromatosis: Onset of two tumors before the age of 5years]. / Neurofibromatose de type 1 : survenue de deux tumeurs avant l'âge de 5 ans.

Neurofibromatosis type 1 (NF1) is a frequent autosomal dominant genetic disorder that predisposes to the development of benign and malignant tumors. Mutation of the NF1 gene affects the RAS-MAPK signaling pathway and leads to a dysfunction in cell proliferation and induces tumor development. Epidemiology of cancer in children with NF1 is very different from the general pediatric population, which requires regular and specific monitoring. Neurofibroma is the most frequent benign tumor. It can be very invalidating depending on the size and location of the tumor. Currently, there is no specific treatment for these tumors. The most frequent malignancies in children with NF1 are leukemias, rhabdomyosarcomas, malignant peripheral nerve sheath tumors and gliomas. The treatment of these tumors should consider the risk of second cancers induced by radio- and chemotherapy. We report on the case of a 5-year-old boy with NF1 developing two tumors.

Influence of glioma tumour microenvironment on the transport of ANG1005 via low-density lipoprotein receptor-related protein 1.

BACKGROUND: ANG1005 consists of three molecules of paclitaxel conjugated via ester bonds to the 19-amino-acid peptide Angiopep-2. The new chemical agent has been shown to cross the blood-brain barrier (BBB) by receptor-mediated transcytosis via low-density lipoprotein receptor-related protein 1 (LRP1). The experiments here examined the role of LRP1 in the subsequent endocytosis of drug into cancer cells. METHODS: Localisation of ANG1005 and Angiopep-2 was examined by immunohistochemistry and in-vivo near-infrared fluorescence imaging in mice carrying orthotopic glioma tumours. Transport of ANG1005 and Angiopep-2 was examined in U87 glioblastoma cell lines. RESULTS: Systemically administered ANG1005 and Cy5.5Angiopep-2 localised to orthotopic glioma tumours in mice. The glioma transplants correlated with high expression levels of LRP1. Decreasing LRP1 activity, by RNA silencing or LRP1 competitors, decreased uptake of ANG1005 and Angiopep-2 into U87 glioblastoma cells. Conversely, LRP1 expression and endocytosis rates for ANG1005 and Angiopep-2 increased in U87 cells under conditions that mimicked the microenvironment near aggressive tumours, that is, hypoxic and acidic conditions. CONCLUSION: ANG1005 might be a particularly effective chemotherapeutic agent for the wide array of known LRP1-expressing brain and non-brain cancers, in particular those with an aggressive phenotype.

Thrombospondin-1 C-terminal-derived peptide protects thyroid cells from ceramide-induced apoptosis through the adenylyl cyclase pathway.

Thrombospondin-1, a multi-modular matrix protein is able to interact with a variety of matrix proteins and cell-surface receptors. Thus it is multifunctional. In this work, we examined the role of thrombospondin-1 in ceramide-induced thyroid apoptosis. We focused on the VVM containing sequence localized in the C-terminal domain of the molecule. Primary cultured thyroid cells synthesize thrombospondin-1 depending on their morphological organization. As it leads thyrocytes to organize into monolayers before inducing apoptosis ceramide can modulate this organization. Here, we established that C(2)-ceramide treatment decreased thrombospondin-1 expression by interfering with the adenylyl cyclase pathway, thus leading to apoptosis. Furthermore, we demonstrated that the thrombospondin-1-derived peptide 4N1 (RFYVVMWK) abolished ceramide-induced thyroid cell death by preventing intracellular cAMP levels from dropping. Finally, we reported that 4N1-mediated inhibition of ceramide-induced apoptosis was consistently associated with a down-regulation of the caspase-3 processing. Integrin-associated protein receptor (IAP or CD47) was identified as a molecular relay mediating the observed 4N1 effects. Taken together, our results shed light for the first time on anti-apoptotic activities of the thrombospondin-1-derived peptide 4N1 and provide new information on how thrombospondin-1 may control apoptosis of non-tumoral cells.

[Paraneoplastic nephrotic syndrome associated with broncho-pulmonary cancer]. / Syndrome néphrotique paranéeoplasique et cancers broncho-pulmonaires. 3 observations et revue de la littérature.

INTRODUCTION: Paraneoplastic nephrotic syndrome associated with malignant broncho-pulmonary tumors. Three cases and literature review. Malignant broncho-pulmonary tumours are the principal cause of a paraneoplastic nephrotic syndrome. These tumours are most often small cell or squamous bronchial carcinomas. In 75% of cases the nephrotic syndrome is due to a membranous glomerulonephritis and it usually precedes the discovery of the causative tumour. CASES REPORT: Three cases of paraneoploastic nephrotic syndrome associated with bronchial carcinoma are described. The first is of a bronchial carcinoid tumour associated with a membrano-proliferative glomerulonephritis. In the second a bronchial adenocarcinoma was revealed by a membranous glomerulonephritis. The last case concerns a squamous carcinoma associated with a nephrotic syndrome in which the histological lesions were not documented on account of progression to rapidly fatal acute renal failure. CONCLUSION: A revue of the literature describes the associations between paraneoplastic nephrotic syndrome and bronchial carcinoma.

Comparison of liquid based cytology and histology for the evaluation of HER-2 status using immunostaining and CISH in breast carcinoma.

BACKGROUND: HER-2 amplification is an important prognostic biomarker and treatment determinant in breast carcinoma. AIMS: To correlate immunocytochemical (ICC) expression of HER-2 and gene amplification determined by chromogenic in situ hybridisation (CISH) using liquid based cytology (LBC) with immunohistochemistry (IHC) and CISH using histological samples of the same breast carcinomas. METHODS: Frozen sections and cytobrushings of 103 breast carcinomas were analysed. Four techniques were performed on each tumour: two on LBC samples (ICC, and CISH, both graded as positive, indeterminate, or negative) and two on histological samples (IHC and CISH). Two cell lines (MCF-7, negative; BT 474, positive) were used as controls for cytological analysis. A complementary fluorescence in situ hybridisation technique was carried out in histological samples with low amplification (4-10 dots/nucleus). RESULTS: Interobserver agreement for the four techniques calculated by the kappa coefficient indicated a substantial agreement. Nine cases failed in cytology because of poor cellularity. Among 94 cases, 19 were amplified; 73, 12, and 9 tumours were scored 0 or 1+, 2+, and 3+, respectively by IHC and 75, 13, and 6, respectively, by ICC. CISH found no amplification in 72 tumours. Correlations between the IHC and CISH results in the histological and cytological samples were always significant. CONCLUSIONS: Her-2 status could be determined in LBC samples and correlated well with reference histological methods using in situ hybridisation. ICC was less reliable because of the presence of the cytoplasmic membrane. However, these results should be confirmed by a large multicentre study.

Thrombospondin 1: a multifunctional protein implicated in the regulation of tumor growth.

Thrombospondins belong to a family of extracellular matrix (ECM) proteins widely found from embryonic to adult tissues. The modular structure of thrombospondins contains a series of peptide sequences implicated in a multiplicity of biological functions. Extracellular matrix undergoes important alterations under proteolysis that occurs in pathological processes like tumorigenesis. An elevated secretion of thrombospondin 1 (TSP1) is often observed in tumors and is sometimes considered as a predictive factor. However, the role of TSP1 in cancer progression remains controversial and must be carefully apprehended. The regulation of cell adhesion, proliferation, apoptosis by TSP1 is examined in the present review and it is clear from the literature and from our investigations that TSP1 presents both stimulatory and inhibitory effects. The exposition of cryptic sites upon conformational changes can partially explain this contradiction. More interestingly, the analysis of TSP1-directed intracellular signaling pathways activated through specific receptors or supramolecular receptors docking systems may be useful to discriminate the precise function of TSP1 in tumor progression. The central role played by TSP1 in the control of matrix-degrading enzyme activation and catabolism reveals attractive tracks of research and highlights the involvement of the lipoprotein receptor-related protein (LRP) receptor in these events. Therefore, TSP1-derived peptides constitute a source of potentially active matrikins which could provide essential tools in cancer therapy.

TGFbeta1 effects on functional activity of porcine thyroid cells cultured in suspension.

Thyrotropin (TSH) and transforming growth factor beta 1 (TGFbeta1) have major roles in the regulation of folliculogenesis and differentiation in thyroid cells. Isolated porcine thyroid cells cultured in the presence of TSH on a plastic surface recover a follicular architecture and exhibit normal functional properties. The addition of TGFbeta1 to the culture medium induces important morphological changes and extracellular matrix remodelling. Similarly, thyroid cells lose their ability to organify iodine and their responsiveness to adenylate cyclase. The aim of this study was to analyse the influence of TGFbeta1 on the functional activity of thyrocytes in suspension culture, independent of follicle disruption. In this system, we demonstrate that TGFbeta1 inhibits expression of thyroperoxidase, NADPH oxidase activity, iodine uptake and, consequently, iodine organification. Moreover, TGFbeta1 decreases basal and TSH-stimulated cAMP production and TSH receptor expression. Taken together, these data converge to demonstrate an essential role of TGFbeta1 in the regulation of the thyroid cell function.

[Malignant blue nevus: clinicopathologic study with AgNOR measurement. Seven cases]. / Naevus bleu malin: étude anatomo-clinique avec quantification des organisateurs nucléolaires argyrophiles (AgNOR): à propos de 7 cas.

BACKGROUND: Malignant blue nevus is a very rare tumor. Argyrophilic nucleolar organizer regions (AgNORs) have been reported to be both a diagnostic and prognostic clue in various tumors, especially if standardized using an image analysis systems. PATIENTS AND METHODS: Seven cases of malignant blue nevus were retrospectively recorded between 1974 and 1999, and their clinical and pathological features described. Using an image analysis system, AgNOR measurements were studied in all cases. These results were compared with those obtained in 10 cases of commun blue nevus, 10 cases of cellular blue nevus and 10 cases of malignant melanoma. RESULTS: The most frequent location of malignant blue nevus was the scalp. Clinically, the tumor generally consisted of a blue nodule, 2.5 cm in diameter. There was no single histopathological criterion for the diagnosis of malignant blue nevus. AgNOR measurement was significantly higher in malignant blue nevus in comparison with commun blue nevus (p<0.0004) or cellular blue nevus (p<0.012), whereas there was no difference between malignant blue naevus and malignant melanoma (p > 0.50). DISCUSSION: Our results confirm the severe prognosis of malignant blue nevus and highlight the necessity of removing all blue tumours located on the scalp. AgNOR measurement using an image analysis system appears to be a useful tool for the diagnosis of malignant blue nevus, but further studies remain necessary.

TSH-induced differentiated functions correlate with enhancement of phosphotyrosine phosphatase activity in thyroid cells. Effect of phorbol 12-myristate 13-acetate.

TSH-treated pig thyroid cells reorganize into follicle-like structures and exhibit differentiated functions. TSH also induces a phosphotyrosine phosphatase (PTPase) activity evaluated by phosphorylated substrate hydrolysis. Incubation of thyrocytes with various concentrations of 8-bromo-cyclic AMP or forskolin induces an increase of PTPase activity in a dose-dependent manner. During the culture period, adenylyl cyclase sensitivity, protein binding iodine and PTPase activity progressively increase from the first to the fourth day of the culture. Chronic treatment with phorbol 12-myristate 13-acetate (PMA) significantly inhibits PTPase activity during the first 24 h following PMA addition. GF 109203X, a specific inhibitor of protein kinase C, abolishes the inhibitory effect of PMA. Electrophoresis of membrane extracts allowed us to demonstrate a phosphatase activity at 111 kDa (p111). Vanadate inhibits this activity, indicating that p111 is a PTPase. This p111 is significantly reduced in PMA-treated cells. These data suggest that PTPase activity evidenced at 111 kDa is correlated with a differentiated state of primary cultured pig thyroid cells induced by TSH.

Expression of vascular endothelial growth factor (VEGF) and its two receptors (VEGF-R1-Flt1 and VEGF-R2-Flk1/KDR) in non-small cell lung carcinomas (NSCLCs): correlation with angiogenesis and survival.

The formation of new vessels (angiogenesis) is essential for primary tumour growth and metastasis and is induced by several angiogenic factors, including vascular endothelial growth factor (VEGF). The microvascular density (MVD) in tumours was assessed and the expression of VEGF and its receptors VEGF-R1-Flt1 and VEGF-R2-KDR/Flk1 was investigated in the different cellular compartments in vivo, in order to establish their interrelationship and their prognostic influence. Immunohistochemical study of 69 stage I-II non-small cell lung carcinomas (NSCLCs) was performed on paraffin sections with CD34 antibody to estimate MVD, using a Chalkley eye-piece graticule and VEGF, VEGF-R1, and VEGF-R2 antibodies. There was strong expression of VEGF and its receptors in tumour cells, endothelial cells, and stromal fibroblasts. In tumour cells, the level of VEGF was correlated with that of VEGF-R1 ( p = 0. 018) but not that of VEGF-R2. In fibroblasts, high expression of VEGF was correlated with that of VEGF-R1 ( p = 0.0001) and VEGF-R2 ( p = 0.0001). In endothelial cells, expression of VEGF was correlated with that of VEGF-R1 ( p < 0.0001) and VEGF-R2 ( p = 0.04). The level of VEGF in fibroblasts was correlated with that of VEGF-R1 ( p = 0.0028) and VEGF-R2 ( p = 0.01) in endothelial cells. There was no correlation between the level of MVD and that of VEGF or VEGF-R1 or VEGF-R2. Neither the level of MVD, nor the level of expression of VEGF and VEGF receptors in any compartment influenced the patient's survival. In conclusion, although angiogenesis is essential for tumour growth, this study failed to demonstrate that MVD, VEGF, VEGF-R1, and VEGF-R2 are prognostic markers for stage I-II NSCLC. VEGF, however, might act as a direct autocrine growth factor for tumour cells via VEGF-R1 and angiogenesis could be promoted in a paracrine loop, where VEGF is produced by fibroblasts and tumour cells and then binds to endothelial cells via induced VEGF receptors. VEGF and its receptors thus appear as relevant therapeutic targets in NSCLC.

Solid alveolar rhabdomyosarcoma of the thorax in a child.

AIMS: This case illustrates the difficulties and pitfalls of diagnosis of alveolar rhabdomyosarcoma in its solid variant and in an unusual primary location, the mediastinum. CASE DETAILS: A 9-year-old boy presented with a primary thoracic tumour associated with metastasis in the left sacroiliac joint. Bronchial and mediastinal biopsies showed a malignant neoplasm with a solid sheet-like pattern of small round cells with a high nuclear to cytoplasmic ratio associated with little or no fibrosis usually evocative of a peripheral neuroectodermal tumour (PNET) at this age. Immunohistochemical positive staining with vimentin (80% of tumour cells), desmin (20%) and titin (30%) antibodies was suggestive of a rhabdomyosarcoma. In addition, all neural cell adhesion molecule (NCAM) markers tested were positive as well as MIC2, a marker for the Ewing family of sarcomas. There was no rhabdomyoid differentiation at ultrastructural examination. Molecular analysis with RT-PCR amplification of RNA isolated from the tumour demonstrated the presence of a PAX3/FKHR fusion transcript, product of a t(2;13) reciprocal translocation, a genetic marker specific for alveolar rhabdomyosarcoma. CONCLUSIONS: The diagnostic methodology of a small round cell tumour of the child must now include immunohistochemical study and molecular biology to confirm the diagnosis of alveolar rhabdomyosarcoma, in a solid and undifferentiated variant.

Glycosyl phosphatidylinositol (GPI)/inositolphosphate glycan (IPG): an intracellular signalling system involved in the control of thyroid cell proliferation.

In porcine thyrocytes, TSH alone does not induce cell growth. Recently, it has been demonstrated that acute stimulation by TSH of porcine thyrocytes leads to release an inositolphosphate glycan (IPG) described as a putative second messenger for various growth factors in different cell types. IPG isolated from porcine thyrocytes induces proliferation of fibroblasts EGFR T17 and porcine thyrocytes. In porcine thyrocytes we have confirmed that cell growth requires the presence of both TSH and insulin. This effect is reproduced by 8-bromo cyclic AMP suggesting a mediation by intracellular cyclic AMP. Cooperative effects between 8-bromo cyclic AMP and IPG have also been evidenced and are in favour of a crosstalk between distinct signalling pathways.

Flavonoids extracted from fonio millet (Digitaria exilis) reveal potent antithyroid properties.

Digitaria exilis (fonio) is a tiny variety of millet commonly eaten by inhabitants of semiarid regions. A sample of fonio collected right in the middle of a severely iodine-depleted goitrous endemic was submitted to phytochemical investigations in order to assess the potential contributory roles played by vegetable molecules to the goitrogenic processes. The total content of flavonoids amounts to 500 mg/kg of the edible whole cereal grains. Their extraction and identification fail to detect the C-glycosylflavones described in other millet varieties but point out the presence of apigenin (A = 150 mg/kg) and of luteolin (L1 = 350 mg/kg). Ten percent of A and 80% of L1 are present in free form, whereas the remaining 90% of A and 20% of L1 are bound as O-glycosylflavones. Both A and L1 aglycones manifest strong anti-thyroid peroxidase (TPO) activities, resulting in a significant reduction of the hormonogenic capacity of this enzyme. In addition, L1 significantly depresses the cyclic AMP phosphodiesterase, implying a concomitant overproduction of the thyrotropin-dependent nucleotide. These last unreported data are regarded as counteracting to some extent the TPO-mediated goitrogenic properties of L1. Since fonio is devoid of other molecules likely to interfere with the thyroid function, our results are directly and casually attributed to A and L1 found in the customary diet.

[Post-partum malignant amebic colitis. Apropos of a case]. / Amibiase colique maligne du post-partum. A propos d'un cas.

A 26-year old female developed acute fulminant amoebic colitis during the post-partum period, successfully managed by subtotal colonic resection without anastomosis. Fulminant transmural amoebic colitis is a rare life-threatening complication of invasive bowel amebiasis. Pregnancy, delivery, diabetes mellitus and immunodeficiency are the main risk factors. At pathologic examination, bowel wall necrosis can be seen with amoebae present in the lumen of capillary vessels. The diagnosis of amoebic colonic perforation is difficult, especially in a non-endemic area. Conservative surgical management is required in non-perforated forms. If perforated, the bowel must be resected, limited to macroscopic lesions.

IPG (inositolphosphate glycan) as a cellular signal for TGF-beta 1 modulation of chondrocyte cell cycle.

The knowledge of transforming growth factor (TGF)-beta receptors has greatly progressed in the recent years. TGF-beta receptors type I and II have been implicated in the modulation of cell proliferation, whereas type III (betaglycan) may act as a component presenting TGF-beta to its signaling receptors. In addition, four other proteins that bind TGF-beta 1 or TGF-beta 2 have been recently identified in some cell lines, three being anchored to the membrane through a glycosylphosphatidylinositol (GPI). Despite this knowledge, the molecular mechanism of signal transduction through the TGF-beta receptors remain an enigma. TGF-beta family does not signal via any of the classical pathways. As GPI anchors of membrane proteins have been implicated in the transduction of some hormonal effects, we investigated the putative role of GPI in signaling the TGF-beta effects on the proliferation of rabbit articular chondrocytes (RAC). We previously showed that TGF-beta 1 increased DNA replication rate of RAC, with a recruitment of cells in G2/M followed by a subsequent mitosis wave. Here, we find that the factor causes specific GPI hydrolysis, with correlated increase of inositolphosphate glycan (IPG). This effect was specifically inhibited by antibodies that bind TGF-beta 1. Using [3H]-inositol labeling and Triton X-114 extraction, we demonstrate that a hydrophobic material from the membrane is cleaved by treatment of cell cultures with phosphatidylinositol specific phospholipase C (PI-PLC) or by exposure to TGF-beta, supporting that a PI-anchored molecule gives rise to IPG by TGF-beta-induced hydrolysis. The biological relevance of this hydrolysis was demonstrated by the enhancing effect of purified IPG on the DNA synthesis rate, which mimicked the TGF-beta action. These results demonstrate that IPG could be an early messenger in the cellular signaling that mediates the effect of TGF-beta on RAC growth.