Publications by authors named "Judith Favier"

83 Publications

Loss of SDHB Promotes Dysregulated Iron Homeostasis, Oxidative Stress, and Sensitivity to Ascorbate.

Cancer Res 2021 Jul 14;81(13):3480-3494. Epub 2021 Jun 14.

PARCC, INSERM UMR970, Equipe Labellisée par la Ligue Contre le Cancer, Paris, France.

Succinate dehydrogenase is a key enzyme in the tricarboxylic acid cycle and the electron transport chain. All four subunits of succinate dehydrogenase are tumor suppressor genes predisposing to paraganglioma, but only mutations in the SDHB subunit are associated with increased risk of metastasis. Here we generated an knockout chromaffin cell line and compared it with deficient cells. Both cell types exhibited similar SDH loss of function, metabolic adaptation, and succinate accumulation. In contrast, cells showed hallmarks of mesenchymal transition associated with increased DNA hypermethylation and a stronger pseudo-hypoxic phenotype compared with cells. Loss of SDHB specifically led to increased oxidative stress associated with dysregulated iron and copper homeostasis in the absence of NRF2 activation. High-dose ascorbate exacerbated the increase in mitochondrial reactive oxygen species, leading to cell death in cells. These data establish a mechanism linking oxidative stress to iron homeostasis that specifically occurs in -deficient cells and may promote metastasis. They also highlight high-dose ascorbate as a promising therapeutic strategy for SDHB-related cancers. SIGNIFICANCE: Loss of different succinate dehydrogenase subunits can lead to different cell and tumor phenotypes, linking stronger 2-OG-dependent dioxygenases inhibition, iron overload, and ROS accumulation following SDHB mutation.
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http://dx.doi.org/10.1158/0008-5472.CAN-20-2936DOI Listing
July 2021

Sunitinib-induced cardiac hypertrophy and the endothelin axis.

Theranostics 2021 6;11(8):3830-3838. Epub 2021 Feb 6.

Université de Paris, PARCC, INSERM, F-75015 Paris.

Anti-angiogenics drugs in clinical use for cancer treatment induce cardiotoxic side effects. The endothelin axis is involved in hypertension and cardiac remodelling, and addition of an endothelin receptor antagonist to the anti-angiogenic sunitinib was shown to reduce cardiotoxicity of sunitinib in mice. Here, we explored further the antidote effect of the endothelin receptor antagonist macitentan in sunitinib-treated animals on cardiac remodeling. Tumor-bearing mice treated daily by sunitinib or vehicle were imaged before and after 1, 3 and 6 weeks of treatment by positron emission tomography using [F]fluorodeoxyglucose and by echocardiography. Non-tumor-bearing animals were randomly assigned to be treated daily by vehicle or sunitinib or macitentan or sunitinib+macitentan, and imaged by echocardiography after 5 weeks. Hearts were harvested for histology and molecular analysis at the end of exploration. Sunitinib treatment increases left ventricular mass and ejection fraction and induces cardiac fibrosis. Sunitinib also induces an early increase in cardiac uptake of [F]fluorodeoxyglucose, which is significantly correlated with increased left ventricular mass at the end of treatment. Co-administration of macitentan prevents sunitinib-induced hypertension, increase in ejection fraction and cardiac fibrosis, but fails to prevent increase of the left ventricular mass. Early metabolic changes predict sunitinib-induced cardiac remodeling. Endothelin blockade can prevent some but not all cardiotoxic side-effects of sunitinib, in particular left ventricle hypertrophy that appears to be induced by sunitinib through an endothelin-independent mechanism.
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http://dx.doi.org/10.7150/thno.49837DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7914356PMC
February 2021

Screening of a Large Cohort of Asymptomatic SDHx Mutation Carriers in Routine Practice.

J Clin Endocrinol Metab 2021 Mar;106(3):e1301-e1315

Department of Nuclear Medicine, Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France.

Context: When an SDHx mutation is identified in a patient with a pheochromocytoma (PCC) or a paraganglioma (PGL), predictive genetic testing can detect mutation carriers that would benefit from screening protocols.

Objective: To define the tumor detection rate in a large cohort of asymptomatic SDHX mutation carriers.

Design And Setting: Retrospective multicentric study in 6 referral centers.

Patients: Between 2005 and 2019, 249 asymptomatic SDHx (171 SDHB, 31 SDHC, 47 SDHD) mutation carriers, with at least 1 imaging work-up were enrolled.

Results: Initial work-up, including anatomical (98% of subjects [97-100% according to center]) and/or functional imaging (67% [14-90%]) detected 48 tumors in 40 patients. After a negative initial work-up, 124 patients benefited from 1 to 9 subsequent follow-up assessments (mean: 1.9 per patient), with a median follow-up time of 5 (1-13) years. Anatomical (86% [49-100 %]) and/or functional imaging (36% [7-60 %]) identified 10 new tumors (mean size: 16 mm [4-50]) in 10 patients. Altogether, 58 tumors (55 paraganglioma [PGL], including 45 head and neck PGL, 2 pheochromocytoma [PCC], 1 gastrointestinal stromal tumor [GIST]), were detected in 50 patients (22 [13%] SDHB, 1 [3.2%] SDHC, and 27 [57%] SDHD), with a median age of 41 years old [11-86], 76% without catecholamine secretion and 80% during initial imaging work-up.

Conclusions: Imaging screening enabled detection of tumors in 20% of asymptomatic SDHx mutation carriers, with a higher detection rate in SDHD (57%) than in SDHB (13%) and SDHC (3%) mutation carriers, arguing for a gene-by-gene approach. Prospective studies using well-defined protocols are needed to obtain strong and useful data.
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http://dx.doi.org/10.1210/clinem/dgaa888DOI Listing
March 2021

An update on adult forms of hereditary pheochromocytomas and paragangliomas.

Curr Opin Oncol 2021 01;33(1):23-32

Université de Paris, PARCC, INSERM, Equipe Labellisée par la Ligue contre le Cancer, Paris, France.

Purpose Of Review: Pheochromocytomas and paragangliomas (PPGL) display a strong genetic determinism with 40% of inherited forms. The purpose of this review is to provide an update on current knowledge on adult forms of hereditary PPGL and their management.

Recent Findings: PPGL are genetically-driven in 70% of cases, with germline and/or somatic mutations identified in more than 20 genes. Although eight new susceptibility genes have recently emerged, mutations on SDHx genes remain the most frequent. In addition to SDHB, mutations in SLC25A11, FH and MDH2 may predispose to a metastatic disease and somatic alterations including TERT and ATRX mutations, and the differential expression on noncoding RNAs are also associated with the occurrence of metastases.The biochemical diagnosis remains the mainstay of functional PPGL and does not differ between hereditary PPGL while the choice of the best nuclear imaging approach is dictated by the tumor type and can be influenced by the presence of a germline mutation (18F-DOPA PET/CT for cluster 2 mutation and Ga-DOTATATE PET/CT for cluster 1 mutation).

Summary: A systematic genetic testing and counselling is recommended for all PPGL patients and should lead to conservative surgery and an adapted follow up, in case of hereditary form.
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http://dx.doi.org/10.1097/CCO.0000000000000694DOI Listing
January 2021

Germline DLST Variants Promote Epigenetic Modifications in Pheochromocytoma-Paraganglioma.

J Clin Endocrinol Metab 2021 Jan;106(2):459-471

Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands.

Context: Pheochromocytomas and paragangliomas (PPGLs) are neuroendocrine tumors in which altered central metabolism appears to be a major driver of tumorigenesis, and many PPGL genes encode proteins involved in the tricarboxylic acid (TCA) cycle.

Objective/design: While about 40% of PPGL cases carry a variant in a known gene, many cases remain unexplained. In patients with unexplained PPGL showing clear evidence of a familial burden or multiple tumors, we aimed to identify causative factors using genetic analysis of patient DNA and functional analyses of identified DNA variants in patient tumor material and engineered cell lines.

Patients And Setting: Patients with a likely familial cancer burden of pheochromocytomas and/or paragangliomas and under investigation in a clinical genetic and clinical research setting in university hospitals.

Results: While investigating unexplained PPGL cases, we identified a novel variant, c.1151C>T, p.(Pro384Leu), in exon 14 of the gene encoding dihydrolipoamide S-succinyltransferase (DLST), a component of the multi-enzyme complex 2-oxoglutarate dehydrogenase. Targeted sequence analysis of further unexplained cases identified a patient carrying a tumor with compound heterozygous variants in DLST, consisting of a germline variant, c.1121G>A, p.(Gly374Glu), together with a somatic missense variant identified in tumor DNA, c.1147A>G, p.(Thr383Ala), both located in exon 14. Using a range of in silico and functional assays we show that these variants are predicted to be pathogenic, profoundly impact enzyme activity, and result in DNA hypermethylation.

Conclusions: The identification and functional analysis of these DLST variants further validates DLST as an additional PPGL gene involved in the TCA cycle.
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http://dx.doi.org/10.1210/clinem/dgaa819DOI Listing
January 2021

Epigenetic and metabolic reprogramming of SDH-deficient paragangliomas.

Endocr Relat Cancer 2020 12;27(12):R451-R463

PARCC, INSERM UMR970, Equipe Labellisée par la Ligue contre le Cancer, Paris, France.

Pheochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumors arising from the adrenal medulla or extra-adrenal paraganglia. Around 40% of all cases are caused by a germline mutation in a susceptibility gene, half of which being found in an SDHx gene (SDHA, SDHB, SDHC, SDHD or SDHAF2). They encode the four subunits and assembly factor of succinate dehydrogenase (SDH), a mitochondrial enzyme involved both in the tricarboxylic acid cycle and electron transport chain. SDHx mutations lead to the accumulation of succinate, which acts as an oncometabolite by inhibiting iron(II) and alpha-ketoglutarate-dependent dioxygenases thereby regulating the cell's hypoxic response and epigenetic processes. Moreover, SDHx mutations induce cell metabolic reprogramming and redox imbalance. Major discoveries in PPGL pathophysiology have been made since the initial discovery of SDHD gene mutations in 2000, improving the understanding of their biology and patient management. It indeed provides new opportunities for diagnostic tools and innovative therapeutic targets in order to improve the prognosis of patients affected by these rare tumors, in particular in the context of metastatic diseases associated with SDHB mutations. This review first describes an overview of the pathophysiology and then focuses on clinical implications of the epigenetic and metabolic reprogramming of SDH-deficient PPGL.
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http://dx.doi.org/10.1530/ERC-20-0346DOI Listing
December 2020

An overview of 20 years of genetic studies in pheochromocytoma and paraganglioma.

Best Pract Res Clin Endocrinol Metab 2020 03 10;34(2):101416. Epub 2020 Mar 10.

Université de Paris, PARCC, INSERM, Equipe Labellisée par la Ligue contre le Cancer, F-75015, Paris, France; Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service de Génétique, F-75015, Paris, France.

Paragangliomas and pheochromocytomas (PPGL) are rare neuroendocrine tumours characterized by a strong genetic determinism. Over the past 20 years, evolution of PPGL genetics has revealed that around 40% of PPGL are genetically determined, secondary to a germline mutation in one of more than twenty susceptibility genes reported so far. More than half of the mutations occur in one of the SDHx genes (SDHA, SDHB, SDHC, SDHD, SDHAF2), which encode the different subunits and assembly protein of a mitochondrial enzyme, succinate dehydrogenase. These susceptibility genes predispose to early forms (VHL, RET, SDHD, EPAS1, DLST), syndromic (RET, VHL, EPAS1, NF1, FH), multiple (SDHD, TMEM127, MAX, DLST, MDH2, GOT2) or malignant (SDHB, FH, SLC25A11) PPGL. The discovery of a germline mutation in one of these genes changes the patient's follow-up and allows genetic screening of affected families and the presymptomatic follow-up of relatives carrying a mutation.
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http://dx.doi.org/10.1016/j.beem.2020.101416DOI Listing
March 2020

TET-Mediated Hypermethylation Primes SDH-Deficient Cells for HIF2α-Driven Mesenchymal Transition.

Cell Rep 2020 03;30(13):4551-4566.e7

Université de Paris, PARCC, INSERM, Equipe Labellisée par la Ligue contre le Cancer, 75015 Paris, France. Electronic address:

Loss-of-function mutations in the SDHB subunit of succinate dehydrogenase predispose patients to aggressive tumors characterized by pseudohypoxic and hypermethylator phenotypes. The mechanisms leading to DNA hypermethylation and its contribution to SDH-deficient cancers remain undemonstrated. We examine the genome-wide distribution of 5-methylcytosine and 5-hydroxymethylcytosine and their correlation with RNA expression in SDHB-deficient tumors and murine Sdhb cells. We report that DNA hypermethylation results from TET inhibition. Although it preferentially affects PRC2 targets and known developmental genes, PRC2 activity does not contribute to the DNA hypermethylator phenotype. We also prove, in vitro and in vivo, that TET silencing, although recapitulating the methylation profile of Sdhb cells, is not sufficient to drive their EMT-like phenotype, which requires additional HIF2α activation. Altogether, our findings reveal synergistic roles of TET repression and pseudohypoxia in the acquisition of metastatic traits, providing a rationale for targeting HIF2α and DNA methylation in SDH-associated malignancies.
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http://dx.doi.org/10.1016/j.celrep.2020.03.022DOI Listing
March 2020

Concurrent imaging of vascularization and metabolism in a mouse model of paraganglioma under anti-angiogenic treatment.

Theranostics 2020 10;10(8):3518-3532. Epub 2020 Feb 10.

Université de Paris, PARCC, INSERM, F-75015 Paris, France.

: Deregulation of metabolism and induction of vascularization are major hallmarks of cancer. Using a new multimodal preclinical imaging instrument, we explored a sequence of events leading to sunitinib-induced resistance in a murine model of paraganglioma (PGL) invalidated for the expression of succinate dehydrogenase subunit B ( ). : Two groups of tumors bearing mice were treated with sunitinib (6 weeks) or vehicle (3 weeks). Concurrent Positron Emission Tomography (PET) with 2' -deoxy-2'-[F]fluoro-D-glucose (FDG), Computed Tomography (CT) and Ultrafast Ultrasound Imaging (UUI) imaging sessions were performed once a week and ex vivo samples were analyzed by western blots and histology. : PET-CT-UUI enabled to detect a rapid growth of tumors with increased glycolysis and vascular development. Sunitinib treatment prevented tumor growth, vessel development and reduced FDG uptake at week 1 and 2 (W1-2). Thereafter, imaging revealed tumor escape from sunitinib treatment: FDG uptake in tumors increased at W3, followed by tumor growth and vessel development at W4-5. Perfused vessels were preferentially distributed in the hypermetabolic regions of the tumors and the perfused volume increased during escape from sunitinib treatment. Finally, initial changes in total lesion glycolysis and maximum vessel length at W1 were predictive of resistance to sunitinib. : These results demonstrate an adaptive resistance of tumors to six weeks of sunitinib treatment. Early metabolic changes and delayed vessel architecture changes were detectable and predictable early during anti-angiogenic treatment. Simultaneous metabolic, anatomical and functional imaging can monitor precisely the effects of anti-angiogenic treatment of tumors.
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http://dx.doi.org/10.7150/thno.40687DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7069082PMC
April 2021

[Pathologist contribution in the diagnosis of hereditary predisposition to paranganglioma and pheochromocytoma].

Ann Pathol 2020 Apr 4;40(2):134-141. Epub 2020 Mar 4.

Service d'anatomopathologie, hôpital européen Georges-Pompidou, Assistance publique-Hôpitaux de Paris (AP-HP Centre), 75015 Paris, France.

Hereditary predispositions are responsible for more than 30% of or paraganglioma. Their identification is essential to optimize medical care and to offer an appropriate screening to relatives. To date, there are more than 15 known paraganglioma/pheochromocytoma predisposing genes. The most frequently involved are those encoding the succinate dehydrogenase (SDHx), accounting for half of cases and the VHL gene, causing the Von Hippel Lindau syndrome and representing approximately 20% of genetically determined cases. Patients with SDHB genes mutations have a higher risk of metastatic disease. An oncogenetic counseling is recommended to all patients developing one or several paragangliomas, isolated or associated with other tumors. Apart from the clinical presentation and in particular the syndromic forms characterized by specific tumor spectra, there is no validated morphological criterion allowing to suspect a hereditary form. On the other hand, pathologists have now access to several immunohistochemical tools allowing the identification of some hereditary forms, in particular those linked to the SDHx, VHL and FH genes. Thus, the loss of expression in immunohistochemistry of the SDHB or FH proteins orientates respectively, towards SDHx and FH genes, while the membrane expression of carbonic anhydrase IX (CA-IX) is a sensitive and specific tool pointing towards a VHL anomaly. Other immunohistochemical markers are under evaluation. A systematic SDHB immunohistochemical staining is recommended on all paragangliomas/pheochromocytomas in order to allow an early detection of the most common hereditary forms and to contribute to the interpretation of the genetic results in these patients seen in oncogenetics consultation.
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http://dx.doi.org/10.1016/j.annpat.2020.01.010DOI Listing
April 2020

Germline mutations in the new E1' cryptic exon of the gene in patients with tumours of von Hippel-Lindau disease spectrum or with paraganglioma.

J Med Genet 2020 11 29;57(11):752-759. Epub 2020 Jan 29.

Université de Paris, PARCC, INSERM, Equipe Labellisée par la Ligue contre le Cancer, F-75015, Paris, France.

Backgrounds: The incidence of germline mutations in the newly discovered cryptic exon (E1') of gene in patients with von Hippel-Lindau (VHL) disease and in patients with paraganglioma or pheochromocytoma (PPGL) is not currently known.

Methods: We studied a large international multicentre cohort of 1167 patients with a previous negative genetic testing. Germline DNA from 75 patients with a single tumour of the VHL spectrum ('Single VHL tumour' cohort), 70 patients with multiple tumours of the VHL spectrum ('Multiple VHL tumours' cohort), 76 patients with a VHL disease as described in the literature ('VHL-like' cohort) and 946 patients with a PPGL were screened for E1' genetic variants.

Results: Six different genetic variants in E1' were detected in 12 patients. Two were classified as pathogenic, 3 as variants of unknown significance and 1 as benign. The rs139622356 was found in seven unrelated patients but described in only 16 patients out of the 31 390 of the Genome Aggregation Database (p<0.0001) suggesting that this variant might be either a recurrent mutation or a modifier mutation conferring a risk for the development of tumours and cancers of the VHL spectrum.

Conclusions: E1' cryptic exon mutations contribute to 1.32% (1/76) of 'VHL-like' cohort and to 0.11% (1/946) of PPGL cohort and should be screened in patients with clinical suspicion of VHL, and added to panels for Next Generation Sequencing (NGS) diagnostic testing of hereditary PPGL. Our data highlight the importance of studying variants identified in deep intronic sequences, which would have been missed by examining only coding sequences of genes/exomes. These variants will likely be more frequently detected and studied with the upcoming implementation of whole-genome sequencing into clinical practice.
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http://dx.doi.org/10.1136/jmedgenet-2019-106519DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7387210PMC
November 2020

Succinate dehydrogenase deficiency in a chromaffin cell model retains metabolic fitness through the maintenance of mitochondrial NADH oxidoreductase function.

FASEB J 2020 01 22;34(1):303-315. Epub 2019 Nov 22.

Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.

Mutations in succinate dehydrogenase (SDH) lead to the development of tumors in a restricted subset of cell types, including chromaffin cells and paraganglia. The molecular basis for this specificity is currently unknown. We show that loss of SDH activity in a chromaffin cell model does not perturb complex I function, retaining the ability to oxidize NADH within the electron transport chain. This activity supports continued oxidation of substrates within the tricarboxylic acid (TCA) cycle. However, due to the block in the TCA cycle at SDH, the high glutamine oxidation activity is only maintained through an efflux of succinate. We also show that although the mitochondria of SDH-deficient cells are less active per se, their higher mass per cell results in an overall respiratory rate that is comparable with wild-type cells. Finally, we observed that when their mitochondria are uncoupled, SDH-deficient cells are unable to preserve their viability, suggesting that the mitochondrial metabolic network is unable to compensate when exposed to additional stress. We therefore show that in contrast to models of SDH deficiency based on epithelial cells, a chromaffin cell model retains aspects of metabolic "health," which could form the basis of cell specificity of this rare tumor type.
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http://dx.doi.org/10.1096/fj.201901456RDOI Listing
January 2020

Succinate detection using in vivo H-MR spectroscopy identifies germline and somatic SDHx mutations in paragangliomas.

Eur J Nucl Med Mol Imaging 2020 06 13;47(6):1510-1517. Epub 2019 Dec 13.

Université de Paris, PARCC, INSERM, Equipe Labellisée par la Ligue contre le Cancer, F-75015, Paris, France.

Purpose: Germline mutations in genes encoding succinate dehydrogenase (SDH) are frequent in patients with pheochromocytoma and paraganglioma (PPGL). They lead to SDH inactivation, mediating a massive accumulation of succinate, which constitutes a highly specific biomarker of SDHx-mutated tumors when measured in vitro. In a recent pilot study, we showed that magnetic resonance spectroscopy (H-MRS) optimized for succinate detection (SUCCES) could detect succinate in vivo in both allografted mouse models and PPGL patients. The objective of this study was to prospectively assess the diagnostic performances of H-MRS SUCCES sequence for the identification of SDH deficiency in PPGL patients.

Methods: Forty-nine patients presenting with 50 PPGLs were prospectively enrolled in our referral center for H-MRS SUCCES. Two observers blinded to the clinical characteristics and genetic status analyzed the presence of a succinate peak and confronted the results to a composite gold standard combining PPGL genetic testing and/or in vitro protein analyses in the tumor.

Results: A succinate peak was observed in 20 tumors, all of which had proven SDH deficiency using the gold standard (17 patients with germline SDHx mutations, 2 with a somatic SDHD mutation, and 1 with negative SDHB IHC and SDH loss of function). A false negative result was observed in 3 tumors. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of H-MRS SUCCES were respectively 87%, 100%, 100%, 90%, and 94%.

Conclusions: Detection of succinate using H-MRS is a highly specific and sensitive hallmark of SDH-deficiency in PPGLs.
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http://dx.doi.org/10.1007/s00259-019-04633-9DOI Listing
June 2020

Evolutionarily conserved susceptibility of the mitochondrial respiratory chain to SDHI pesticides and its consequence on the impact of SDHIs on human cultured cells.

PLoS One 2019 7;14(11):e0224132. Epub 2019 Nov 7.

Université de Paris, NeuroDiderot, INSERM, Paris, France.

Succinate dehydrogenase (SDH) inhibitors (SDHIs) are used worldwide to limit the proliferation of molds on plants and plant products. However, as SDH, also known as respiratory chain (RC) complex II, is a universal component of mitochondria from living organisms, highly conserved through evolution, the specificity of these inhibitors toward fungi warrants investigation. We first establish that the human, honeybee, earthworm and fungal SDHs are all sensitive to the eight SDHIs tested, albeit with varying IC50 values, generally in the micromolar range. In addition to SDH, we observed that five of the SDHIs, mostly from the latest generation, inhibit the activity of RC complex III. Finally, we show that the provision of glucose ad libitum in the cell culture medium, while simultaneously providing sufficient ATP and reducing power for antioxidant enzymes through glycolysis, allows the growth of RC-deficient cells, fully masking the deleterious effect of SDHIs. As a result, when glutamine is the major carbon source, the presence of SDHIs leads to time-dependent cell death. This process is significantly accelerated in fibroblasts derived from patients with neurological or neurodegenerative diseases due to RC impairment (encephalopathy originating from a partial SDH defect) and/or hypersensitivity to oxidative insults (Friedreich ataxia, familial Alzheimer's disease).
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0224132PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6837341PMC
March 2020

Transcriptome Analysis of lncRNAs in Pheochromocytomas and Paragangliomas.

J Clin Endocrinol Metab 2020 03;105(3)

Paris University, PARCC, INSERM, Equipe labellisée par la Ligue contre le cancer, Paris, France.

Context: Pheochromocytomas and paragangliomas (PPGLs) are neuroendocrine tumors explained by germline or somatic mutations in about 70% of cases. Patients with SDHB mutations are at high risk of developing metastatic disease, yet no reliable tumor biomarkers are available to predict tumor aggressiveness.

Objective: We aimed at identifying long noncoding RNAs (lncRNAs) specific for PPGL molecular groups and metastatic progression.

Design And Methods: To analyze the expression of lncRNAs, we used a mining approach of transcriptome data from a well-characterized series of 187 tumor tissues. Clustering consensus analysis was performed to determine a lncRNA-based classification, and informative transcripts were validated in an independent series of 51 PPGLs. The expression of metastasis-related lncRNAs was confirmed by RT-qPCR. Receiver operating characteristic (ROC) curve analysis was used to estimate the predictive accuracy of potential markers.

Main Outcome Measure: Univariate/multivariate and metastasis-free survival (MFS) analyses were carried out for the assessment of risk factors and clinical outcomes.

Results: Four lncRNA-based subtypes strongly correlated with mRNA expression clusters (chi-square P-values from 1.38 × 10-32 to 1.07 × 10-67). We identified one putative lncRNA (GenBank: BC063866) that accurately discriminates metastatic from benign tumors in patients with SDHx mutations (area under the curve 0.95; P = 4.59 × 10-05). Moreover, this transcript appeared as an independent risk factor associated with poor clinical outcome of SDHx carriers (log-rank test P = 2.29 × 10-05).

Conclusion: Our findings extend the spectrum of transcriptional dysregulations in PPGL to lncRNAs and provide a novel biomarker that could be useful to identify potentially metastatic tumors in patients carrying SDHx mutations.
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http://dx.doi.org/10.1210/clinem/dgz168DOI Listing
March 2020

Integrative multi-omics analysis identifies a prognostic miRNA signature and a targetable miR-21-3p/TSC2/mTOR axis in metastatic pheochromocytoma/paraganglioma.

Theranostics 2019 9;9(17):4946-4958. Epub 2019 Jul 9.

Department of Internal Medicine, Radboud University Medical Centre, 6525 HP Nijmegen, The Netherlands.

: Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors that present variable outcomes. To date, no effective therapies or reliable prognostic markers are available for patients who develop metastatic PPGL (mPPGL). Our aim was to discover robust prognostic markers validated through models, and define specific therapeutic options according to tumor genomic features. : We analyzed three PPGL miRNome datasets (n=443), validated candidate markers and assessed them in serum samples (n=36) to find a metastatic miRNA signature. An integrative study of miRNome, transcriptome and proteome was performed to find miRNA targets, which were further characterized . : A signature of six miRNAs (miR-21-3p, miR-183-5p, miR-182-5p, miR-96-5p, miR-551b-3p, and miR-202-5p) was associated with metastatic risk and time to progression. A higher expression of five of these miRNAs was also detected in PPGL patients' liquid biopsies compared with controls. The combined expression of miR-21-3p/miR-183-5p showed the best power to predict metastasis (AUC=0.804, =4.67·10), and was found associated with pro-metastatic features, such as neuroendocrine-mesenchymal transition phenotype, and increased cell migration rate. A pan-cancer multi-omic integrative study correlated miR-21-3p levels with TSC2 expression, mTOR pathway activation, and a predictive signature for mTOR inhibitor-sensitivity in PPGLs and other cancers. Likewise, we demonstrated a repression and an enhanced rapamycin sensitivity upon miR-21-3p expression. : Our findings support the assessment of miR-21-3p/miR-183-5p, in tumors and liquid biopsies, as biomarkers for risk stratification to improve the PPGL patients' management. We propose miR-21-3p to select mPPGL patients who may benefit from mTOR inhibitors.
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http://dx.doi.org/10.7150/thno.35458DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6691382PMC
August 2020

Carbonic anhydrase 9 immunohistochemistry as a tool to predict or validate germline and somatic VHL mutations in pheochromocytoma and paraganglioma-a retrospective and prospective study.

Mod Pathol 2020 01 5;33(1):57-64. Epub 2019 Aug 5.

Université de Paris, PARCC, INSERM, Equipe Labellisée par la Ligue contre le Cancer, F-75015, Paris, France.

The development of pheochromocytomas and paragangliomas is strongly linked to the presence of germline mutations in more than 15 predisposing genes. Among them, germline and somatic VHL mutations account for ~10% of all cases. In contrast with SDHA and SDHB immunohistochemistries that are routinely used to validate SDHx gene mutations, there is no such tool available for VHL mutations. The aim of this study was to evaluate whether CA9 immunostaining could be used as a tool to predict the presence or validate the pathogenicity of VHL gene mutations in paraganglioma. Immunohistochemistry for CA9 was performed on 207 tumors. A retrospective series of 100 paragangliomas with known mutation status for paraganglioma susceptibility genes was first investigated. Then, a prospective series of 107 paragangliomas was investigated for CA9 immunostaining followed by germline and/or somatic genetic testing of all paraganglioma susceptibility genes by next-generation sequencing. Cytosolic CA9 protein expression was heterogeneous in the different samples. However, we observed that a membranous CA9 staining was almost exclusively observed in VHL-related cases. Forty two of 48 (88%) VHL-mutated samples showed a CA9 membranous immunostaining. Positive cells were either isolated, varying from 1 or 2 cells (5% of cases) to 10-20 cells per tumor block (35% of cases), grouped in areas of focal positivity representing between 1 and 20% of the tissue section (35% of cases), or widely distributed on 80-100% of the tumor sections (25% of samples). In contrast, 142/159 (91%) of non-VHL-mutated tumors presented no membrane CA9 localization. Our results demonstrate that VHL gene mutations can be predicted or validated reliably by an easy-to-perform and low-cost immunohistochemical procedure. CA9 immunohistochemistry on paragangliomas will improve the diagnosis of VHL-related disease, which is important for the surveillance and therapeutic management of paraganglioma patients, and in case of germline mutation, their family members.
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http://dx.doi.org/10.1038/s41379-019-0343-4DOI Listing
January 2020

Synergistic Highly Potent Targeted Drug Combinations in Different Pheochromocytoma Models Including Human Tumor Cultures.

Endocrinology 2019 11;160(11):2600-2617

Medizinische Klinik und Poliklinik IV, Klinikum der Universität, LMU München, Munich, Germany.

There are no officially approved therapies for metastatic pheochromocytomas apart from ultratrace 131I-metaiodbenzylguanidine therapy, which is approved only in the United States. We have, therefore, investigated the antitumor potential of molecular-targeted approaches in murine pheochromocytoma cell lines [monocyte chemoattractant protein (MPC)/monocyte chemoattractant protein/3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)], immortalized mouse chromaffin Sdhb-/- cells, three-dimensional pheochromocytoma tumor models (MPC/MTT spheroids), and human pheochromocytoma primary cultures. We identified the specific phosphatidylinositol-3-kinase α inhibitor BYL719 and the mammalian target of rapamycin inhibitor everolimus as the most effective combination in all models. Single treatment with clinically relevant doses of BYL719 and everolimus significantly decreased MPC/MTT and Sdhb-/- cell viability. A targeted combination of both inhibitors synergistically reduced MPC and Sdhb-/- cell viability and showed an additive effect on MTT cells. In MPC/MTT spheroids, treatment with clinically relevant doses of BYL719 alone or in combination with everolimus was highly effective, leading to a significant shrinkage or even a complete collapse of the spheroids. We confirmed the synergism of clinically relevant doses of BYL719 plus everolimus in human pheochromocytoma primary cultures of individual patient tumors with BYL719 attenuating everolimus-induced AKT activation. We have thus established a method to assess molecular-targeted therapies in human pheochromocytoma cultures and identified a highly effective combination therapy. Our data pave the way to customized combination therapy to target individual patient tumors.
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http://dx.doi.org/10.1210/en.2019-00410DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6795182PMC
November 2019

Emerging molecular markers of metastatic pheochromocytomas and paragangliomas.

Ann Endocrinol (Paris) 2019 Jun 11;80(3):159-162. Epub 2019 Apr 11.

Inserm, UMR970, équipe labellisée Ligue Contre le Cancer, Paris-Cardiovascular Research Center, 75015 Paris, France; Faculté de médecine, PRES Sorbonne Paris-Cité, Paris-Descartes University, 75006 Paris, France. Electronic address:

Metastatic pheochromocytoma/paraganglioma (PPGL) represents a major clinical challenge due to limitations in accurate diagnostic tools and effective treatments. Currently, patients classified at high-risk by means of clinical, biochemical and genetic criteria, require a lifelong monitoring, while it remains difficult to determine the metastatic potential of PPGL only on the basis of histopathological features. Thus, tumor molecular markers that improve the risk stratification of these patients are needed. In the past few years, we have witnessed an unprecedented molecular characterization of PPGL, which led to the emergence of promising candidate biomarkers predictive of metastatic behavior. Here, we briefly discuss these breakthroughs and provide some insights for the prospective implementation of molecular markers of metastatic PPGL in the clinical setting in years to come.
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http://dx.doi.org/10.1016/j.ando.2019.04.003DOI Listing
June 2019

Targeted next-generation sequencing detects rare genetic events in pheochromocytoma and paraganglioma.

J Med Genet 2019 08 15;56(8):513-520. Epub 2019 Mar 15.

Genetics department, Assistance Publique-Hôpitaux de Paris, Hôpitaleuropéen Georges Pompidou, F-75015, Paris, France.

Background: Knowing the genetic status of patients affected by paragangliomas and pheochromocytomas (PPGL) is important for the guidance of their management and their relatives. Our objective was to improve the diagnostic performances of PPGL genetic testing by next-generation sequencing (NGS).

Methods: We developed a custom multigene panel, which includes 17 PPGL genes and is compatible with both germline and tumour DNA screening. The NGS assay was first validated in a retrospective cohort of 201 frozen tumour DNAs and then applied prospectively to 623 DNAs extracted from leucocytes, frozen or paraffin-embedded PPGL tumours.

Results: In the retrospective cohort, the sensitivity of the NGS assay was evaluated at 100% for point and indels mutations and 86% for large rearrangements. The mutation rate was re-evaluated from 65% (132/202) to 78% (156/201) after NGS analysis. In the prospective cohort, NGS detected not only germline and somatic mutations but also co-occurring variants and mosaicism. A mutation was identified in 74% of patients for whom both germline and tumour DNA were available.

Conclusion: The analysis of 824 DNAs from patients with PPGL demonstrated that NGS assay significantly improves the performances of PPGL genetic testing compared with conventional methods, increasing the rate of identified mutations and identifying rare genetic mechanisms.
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http://dx.doi.org/10.1136/jmedgenet-2018-105714DOI Listing
August 2019

Positive Impact of Genetic Test on the Management and Outcome of Patients With Paraganglioma and/or Pheochromocytoma.

J Clin Endocrinol Metab 2019 04;104(4):1109-1118

Assistance Publique, Hôpitaux de Paris, Hôpital Cochin, Service d'Endocrinologie, Centre de Référence Maladies Rares de la Surrénale, Paris, France.

Context: Pheochromocytomas and paragangliomas (PPGLs) are characterized by a strong genetic component, with up to 40% of patients carrying a germline mutation in a PPGL susceptibility gene. International guidelines recommend that genetic screening be proposed to all patients with PPGL.

Objective: Our objective was to evaluate how a positive genetic test impacts the management and outcome of patients with SDHx or VHL-related PPGL.

Design: We performed a multicentric retrospective study involving 221 propositi carrying an SDHB, SDHD, SDHC, or VHL germline mutation. Patients were divided into two groups: genetic patients, who were informed of their genetic status within the year following the first PPGL diagnosis, and historic patients, who only benefited from the genetic test several years after initial PPGL diagnosis.

Results: Genetic patients had better follow-up than historic patients, with a greater number of examinations and a reduced number of patients lost to follow-up (9.6% vs 72%, respectively). During follow-up, smaller (18.7 vs 27.6 mm; P = 0.0128) new PPGLs and metastases as well as lower metastatic spread were observed in genetic patients. Of note, these differences were reversed in the historic cohort after genetic testing. Genetic patients who developed metachronous metastases had a better 5-year survival rate than historic patients (P = 0.0127).

Conclusion: Altogether, our data suggest that early knowledge of genetic status had a positive impact on the management and clinical outcome of patients with a germline SDHx or VHL mutation.
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http://dx.doi.org/10.1210/jc.2018-02411DOI Listing
April 2019

Telomerase Activation and ATRX Mutations Are Independent Risk Factors for Metastatic Pheochromocytoma and Paraganglioma.

Clin Cancer Res 2019 01 9;25(2):760-770. Epub 2018 Oct 9.

INSERM, UMR970, Paris-Cardiovascular Research Center, Equipe Labellisée par la Ligue contre le Cancer, Paris, France.

Purpose: Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors. Whereas most PPGLs are benign, up to 20% may become metastatic with - and -mutated tumors showing the higher risk. We aimed at determining the contribution of immortalization mechanisms to metastatic progression. Immortalization mechanisms were investigated in 200 tumors. To identify telomerase (+) tumors, we analyzed genomic alterations leading to transcriptional activation of comprising promoter mutations, hypermethylation and gain copy number. To identify tumors that activated the alternative lengthening of telomere (ALT) mechanism, we combined analyses of telomere length by slot blot, telomere heterogeneity by telomere FISH, and mutations by next-generation sequencing. Univariate/multivariate and metastasis-free survival (MFS) and overall survival (OS) analyses were carried out for assessment of risk factors and clinical outcomes.

Results: Only 37 of 200 (18.5%) tumors achieved immortalization. Telomerase activation occurred in 12 metastatic tumors and was prevalent in -mutated paragangliomas ( = 2.42e-09). ALT features were present in 25 tumors, mostly pheochromocytomas, regardless of metastatic status or molecular group ( = 0.169), yet mutations were found preferentially in -mutated metastatic tumors ( = 0.0014). Telomerase activation and mutations were independent factors of poor prognosis: MFS (hazard ratio, 48.2 and 33.1; = 6.50E-07 and 1.90E-07, respectively); OS (hazard ratio, 97.4 and 44.1; = 4.30E-03 and 2.00E-03, respectively) and were associated with worse MFS and OS (log-rank tests < 0.0001).

Conclusions: Assessment of telomerase activation and mutations could be used to identify metastatic PPGLs, particularly in tumors at high risk of progression.
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http://dx.doi.org/10.1158/1078-0432.CCR-18-0139DOI Listing
January 2019

Role of MDH2 pathogenic variant in pheochromocytoma and paraganglioma patients.

Genet Med 2018 12 16;20(12):1652-1662. Epub 2018 Jul 16.

Hereditary Endocrine Cancer Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain.

Purpose: MDH2 (malate dehydrogenase 2) has recently been proposed as a novel potential pheochromocytoma/paraganglioma (PPGL) susceptibility gene, but its role in the disease has not been addressed. This study aimed to determine the prevalence of MDH2 pathogenic variants among PPGL patients and determine the associated phenotype.

Methods: Eight hundred thirty patients with PPGLs, negative for the main PPGL driver genes, were included in the study. Interpretation of variants of unknown significance (VUS) was performed using an algorithm based on 20 computational predictions, by implementing cell-based enzymatic and immunofluorescence assays, and/or by using a molecular dynamics simulation approach.

Results: Five variants with potential involvement in pathogenicity were identified: three missense (p.Arg104Gly, p.Val160Met and p.Ala256Thr), one in-frame deletion (p.Lys314del), and a splice-site variant (c.429+1G>T). All were germline and those with available biochemical data, corresponded to noradrenergic PPGL.

Conclusion: This study suggests that MDH2 pathogenic variants may play a role in PPGL susceptibility and that they might be responsible for less than 1% of PPGLs in patients without pathogenic variants in other major PPGL driver genes, a prevalence similar to the one recently described for other PPGL genes. However, more epidemiological data are needed to recommend MDH2 testing in patients negative for other major PPGL genes.
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http://dx.doi.org/10.1038/s41436-018-0068-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7456538PMC
December 2018

Germline Mutations in the Mitochondrial 2-Oxoglutarate/Malate Carrier Gene Confer a Predisposition to Metastatic Paragangliomas.

Cancer Res 2018 04 5;78(8):1914-1922. Epub 2018 Feb 5.

INSERM, UMR970, Paris-Centre de Recherche Cardiovasculaire, Paris, France; Equipe labellisée Ligue contre le Cancer.

Comprehensive genetic analyses have identified germline and gene mutations as predominant causes of metastatic paraganglioma and pheochromocytoma. However, some suspicious cases remain unexplained. In this study, we performed whole-exome sequencing of a paraganglioma exhibiting an -like molecular profile in the absence of or mutations and identified a germline mutation in the gene, which encodes the mitochondrial 2-oxoglutarate/malate carrier. Germline mutations were identified in six other patients, five of whom had metastatic disease. These mutations were associated with loss of heterozygosity, suggesting that acts as a tumor-suppressor gene. Pseudohypoxic and hypermethylator phenotypes comparable with those described in - and -related tumors were observed both in tumors with mutated and in immortalized mouse chromaffin knockout cells generated by CRISPR-Cas9 technology. These data show that is a novel paraganglioma susceptibility gene for which loss of function correlates with metastatic presentation. A gene encoding a mitochondrial carrier is implicated in a hereditary cancer predisposition syndrome, expanding the role of mitochondrial dysfunction in paraganglioma. .
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http://dx.doi.org/10.1158/0008-5472.CAN-17-2463DOI Listing
April 2018

Rodent models of pheochromocytoma, parallels in rodent and human tumorigenesis.

Cell Tissue Res 2018 05 9;372(2):379-392. Epub 2018 Feb 9.

INSERM UMR970, Paris-Cardiovascular Research Center, Equipe Labellisée Ligue Contre le Cancer, 56 rue Leblanc, F-75015, Paris, France.

Paragangliomas and pheochromocytomas are rare neuroendocrine tumors characterized by a large spectrum of hereditary predisposition. Based on gene expression profiling classification, they can be classically assigned to either a hypoxic/angiogenic cluster (cluster 1 including tumors with mutations in SDHx, VHL and FH genes) or a kinase-signaling cluster (cluster 2 consisting in tumors related to RET, NF1, TMEM127 and MAX genes mutations, as well as most of the sporadic tumors). The past 15 years have seen the emergence of an increasing number of genetically engineered and grafted models to investigate tumorigenesis and develop new therapeutic strategies. Among them, only cluster 2-related predisposed models have been successful but grafted models are however available to study cluster 1-related tumors. In this review, we present an overview of existing rodent models targeting predisposition genes involved or not in human pheochromocytoma/paraganglioma susceptibility and their contribution to the improvement of pheochromocytoma experimental research.
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http://dx.doi.org/10.1007/s00441-018-2797-yDOI Listing
May 2018

Simultaneous positron emission tomography and ultrafast ultrasound for hybrid molecular, anatomical and functional imaging.

Nat Biomed Eng 2018 02 6;2(2):85-94. Epub 2018 Feb 6.

Inserm, UMR970, Paris Cardiovascular Research Center, Paris, France.

Positron emission tomography-computed tomography (PET-CT) is the most sensitive molecular imaging modality, but it does not easily allow for rapid temporal acquisition. Ultrafast ultrasound imaging (UUI)-a recently introduced technology based on ultrasonic holography-leverages frame rates of up to several thousand images per second to quantitatively map, at high resolution, haemodynamic, biomechanical, electrophysiological and structural parameters. Here, we describe a pre-clinical scanner that registers PET-CT and UUI volumes acquired simultaneously and offers multiple combinations for imaging. We demonstrate that PET-CT-UUI allows for simultaneous images of the vasculature and metabolism during tumour growth in mice and rats, as well as for synchronized multi-modal cardiac cine-loops. Combined anatomical, functional and molecular imaging with PET-CT-UUI represents a high-performance and clinically translatable technology for biomedical research.
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http://dx.doi.org/10.1038/s41551-018-0188-zDOI Listing
February 2018

Establishment of a mouse xenograft model of metastatic adrenocortical carcinoma.

Oncotarget 2017 Aug 7;8(31):51050-51057. Epub 2017 Apr 7.

Université Côte d'Azur, Valbonne, Sophia Antipolis, France.

Adrenocortical carcinoma is a rare neoplasm with a poor prognosis. Very important advances have been made in the identification of the genetic determinants of adrenocortical carcinoma pathogenesis but our understanding is still limited about the mechanisms that determine cancer spread and metastasis. One major problem hindering preclinical experimentation for new therapies for adrenocortical carcinoma is represented by the lack of suitable animal models for metastatic disease. With the aim to overcome these limitations, in this study we tested several protocols in order to establish a mouse xenograft model of metastatic adrenocortical carcinoma. The most efficient method, based upon intrasplenic injection followed by splenectomy, produced metastases with high efficiency, whose development could be followed over time by bioluminescence measurements. We expect that the availability of this model will greatly improve the possibilities for preclinical testing of new treatments for advanced-stage disease.
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http://dx.doi.org/10.18632/oncotarget.16909DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5584229PMC
August 2017

Mitochondrial Deficiencies in the Predisposition to Paraganglioma.

Metabolites 2017 May 4;7(2). Epub 2017 May 4.

INSERM UMR970, Paris-Cardiovascular Research Center at HEGP, F-75015 Paris, France.

Paragangliomas and pheochromocytomas are rare neuroendocrine tumours with a very strong genetic component. It is estimated that around 40% of all cases are caused by a germline mutation in one of the 13 predisposing genes identified so far. Half of these inherited cases are intriguingly caused by mutations in genes encoding tricarboxylic acid enzymes, namely , , , , and genes, encoding succinate dehydrogenase and its assembly protein, encoding fumarate hydratase, and encoding malate dehydrogenase. These mutations may also predispose to other type of cancers, such as renal cancer, leiomyomas, or gastro-intestinal stromal tumours. SDH, which is also the complex II of the oxidative respiratory chain, was the first mitochondrial enzyme to be identified having tumour suppressor functions, demonstrating that 80 years after his initial proposal, Otto Warburg may have actually been right when he hypothesized that low mitochondrial respiration was the origin of cancer. This review reports the current view on how such metabolic deficiencies may lead to cancer predisposition and shows that the recent data may lead to the development of innovative therapeutic strategies and establish precision medicine approaches for the management of patients affected by these rare diseases.
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http://dx.doi.org/10.3390/metabo7020017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5487988PMC
May 2017

Dosage-dependent regulation of expression by steroidogenic factor-1 drives adrenocortical carcinoma cell invasion.

Sci Signal 2017 Mar 7;10(469). Epub 2017 Mar 7.

Université Côte d'Azur, Sophia Antipolis, 06560 Valbonne, France.

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with a dismal prognosis. Genomic studies have enabled progress in our understanding of the molecular bases of ACC, but factors that influence its prognosis are lacking. Amplification of the gene encoding the transcription factor steroidogenic factor-1 (SF-1; also known as NR5A1) is one of the genetic alterations common in ACC. We identified a transcriptional regulatory mechanism involving increased abundance of VAV2, a guanine nucleotide exchange factor for small GTPases that control the cytoskeleton, driven by increased expression of the gene encoding SF-1 in ACC. Manipulating SF-1 and VAV2 abundance in cultured ACC cells revealed that VAV2 was a critical factor for SF-1-induced cytoskeletal remodeling and invasion in culture (Matrigel) and in vivo (chicken chorioallantoic membrane) models. Analysis of ACC patient cohorts indicated that greater VAV2 abundance robustly correlated with poor prognosis in ACC patients. Because VAV2 is a druggable target, our findings suggest that blocking VAV2 may be a new therapeutic approach to inhibit metastatic progression in ACC patients.
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http://dx.doi.org/10.1126/scisignal.aal2464DOI Listing
March 2017
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