Mitotic Dysregulation at Tumor Initiation Creates a Therapeutic Vulnerability to Combination Anti-Mitotic and Pro-Apoptotic Agents for MYCN-Driven Neuroblastoma

MYCN amplification occurs in approximately 20-30% of neuroblastoma patients and correlates with poor prognosis. The TH-MYCN transgenic mouse model mimics the development of human high-risk neuroblastoma and provides strong evidence for the oncogenic function of MYCN. In this study, we identified mitotic dysregulation as a hallmark of tumor initiation in the pre-cancerous ganglia from TH-MYCN mice that persists through tumor progression. Single-cell quantitative-PCR of coeliac ganglia from 10-day-old TH-MYCN mice revealed overexpression of mitotic genes in a subpopulation of premalignant neuroblasts at a level similar to single cells derived from established tumors. Prophylactic treatment using antimitotic agents barasertib and vincristine significantly delayed the onset of tumor formation, reduced pre-malignant neuroblast hyperplasia, and prolonged survival in TH-MYCN mice. Analysis of human neuroblastoma tumor cohorts showed a strong correlation between dysregulated mitosis and features of MYCN amplification, such as MYC(N) transcriptional activity, poor overall survival, and other clinical predictors of aggressive disease. To explore the therapeutic potential of targeting mitotic dysregulation, we showed that genetic and chemical inhibition of mitosis led to selective cell death in neuroblastoma cell lines with MYCN over-expression. Moreover, combination therapy with antimitotic compounds and BCL2 inhibitors exploited mitotic stress induced by antimitotics and was synergistically toxic to neuroblastoma cell lines. These results collectively suggest that mitotic dysregulation is a key component of tumorigenesis in early neuroblasts, which can be inhibited by the combination of antimitotic compounds and pro-apoptotic compounds in MYCN-driven neuroblastoma.

Non-invasive assessment of muscle compartment elasticity by pressure-related ultrasound in pediatric trauma: a prospective clinical study in 25 cases of forearm shaft fractures

BACKGROUND

Soft-tissue swelling after limb fractures in pediatric patients is well known to be a risk factor for developing acute compartment syndrome (ACS). Clinical assessment alone is uncertain in specific cases. Recently, we proposed a non-invasive ultrasound-based method to objectify muscle compartment elasticity for monitoring. We hypothesize a strong correlation between the soft-tissue swelling after stabilization of upper limb fractures and the compartment elasticity objectified with a novel ultrasound-based approach in pediatric trauma.

PATIENTS AND METHODS

In a prospective clinical study, children suffering forearm fractures but not developing an ACS were included. The muscle compartment elasticity of the m. flexor carpi ulnaris was assessed after surgical intervention by a non-invasive, ultrasound-based method resulting in a relative elasticity (RE in %) in both the control (healthy limb) and study group (fractured limb). Soft-tissue swelling was categorized in four different levels (0-3) and correlated with the resulting RE (%).

RESULTS

The RE in the study group (15.67%, SD ± 3.06) showed a significantly decreased level (p < 0.001) compared with the control (22.77%, SD ± 5.4). The categorized grade of soft-tissue swelling resulted in a moderate correlation with the RE (rs = 0.474).

CONCLUSIONS

The presented study appears to represent a novel approach to assess the posttraumatic pressure changes in a muscle compartment after fracture stabilization non-invasively. In this first clinical study in pediatric cases, our measurement method represents a low-cost, easy, and secure approach that has the potential to substitute invasive measurement of suspected ACS in muscle compartment conditions. Further investigations in lager cohorts are required to prove its daily clinical practicability and to confirm the expected reliability.

An Infundibular Unidentified Object (IUO): a new pituitary stalk marker?

PURPOSE

Measurement of the pituitary stalk (PS) diameter does not always solve the issue of minimal PS thickening. A previously undescribed image is found at the infundibular level on high resolution thin section T2W MRI in a large number of normal individuals. We speculate that this image-whose exact origin is still unknown-may serve as a marker of the normal infundibulum.

METHODS

In the last 6 months, 350 consecutive adult patients suspected of sellar pathology or controlled after medical or surgical treatment prospectively underwent a pituitary MRI including a sagittal T2W high resolution sequence. One hundred twelwe patients presenting a pituitary mass with suprasellar extension or those whose PS was not entirely visible were excluded.

RESULTS

A short focal annular T2 hypointense thickening of the wall of the infundibular recess of the third ventricle, more pronounced anteriorly was found in 151/238 patients. Additionally, a more or less tiny ventral extension was demonstrated on sagittal T2W sequence in 105/151 patients. These images were not identified on T1W or on T1W gadolinium enhanced sequences. The ring-like infundibular thickening and/or its ventral extension were not identified in 87/238 patients; in 43/87 of these patients the PS was found severely stretched mainly in case of primary or secondary empty sella. If patients with empty sella were excluded, our finding was observed in 194/238 cases, i.e. in 82%.

CONCLUSIONS

A detailed appearance of the PS on T2W MRI is described for the first time. A previously unreported T2W hypointense annular focal image prolonged by a tiny spicular or nodular ventral bud is found at the lower part of the infundibulum in a majority of normal patients, but not if the PS is stretched such as in empty sella. This image has to be recognized as a normal anatomical landmark. The possible origin of this image is discussed but not totally elucidated. An ongoing research will demonstrate or not if this image may serve as a marker to improve the early diagnosis of PS lesions.

[How to explore... hyperandrogenism associated with insulin resistance ? An example based on the HAIR-AN syndrome.]

HAIR-AN, a syndrome associating hyperandrogenism, insulin resistance and acanthosis nigricans, is currently considered as a severe form of polycystic ovary syndrome. The physiopathology of this syndrome relies on the insulin resistance which is the basis of a vicious circle : the resulting hyperinsulinism leads to an excessive production of androgens. The latter increases abdominal fat deposition which in turn worsens the insulin resistance. Hyperinsulinism is also responsible for the acanthosis nigricans by stimulating the IGF-1 receptors on keratinocytes and fibroblasts. Hyperandrogenism is clinically translated into hirsutism that can be severe. Frequently, menstrual irregularity and obesity are part of the syndrome. HAIR-AN syndrome begins soon after puberty and is currently under-diagnosed. Treatment relies on an improvement in insulin-resistance by a loss of body weight and the use of insulin sensitizers. Moreover, anti-androgenic drugs will help improving hirsutism. Although more invasive, bariatric surgery has shown a great efficacy in this syndrome : by permitting a substantial loss of weight, it often normalizes insulin-sensitivity, allowing for improvements in hyperandrogenism and acanthosis nigricans.

MEIS2 Is an Adrenergic Core Regulatory Transcription Factor Involved in Early Initiation of TH-MYCN-Driven Neuroblastoma Formation

Simple Summary

Neuroblastoma is a pediatric tumor originating from the sympathetic nervous system responsible for 10–15% of all childhood cancer deaths. Half of all neuroblastoma patients present with high-risk disease, of which nearly 50% relapse and die of their disease. In addition, standard therapies cause serious lifelong side effects and increased risk for secondary tumors. Further research is crucial to better understand the molecular basis of neuroblastomas and to identify novel druggable targets. Neuroblastoma tumorigenesis has to this end been modeled in both mice and zebrafish. Here, we present a detailed dissection of the gene expression patterns that underlie tumor formation in the murine TH-MYCN-driven neuroblastoma model. We identified key factors that are putatively important for neuroblastoma tumor initiation versus tumor progression, pinpointed crucial regulators of the observed expression patterns during neuroblastoma development and scrutinized which factors could be innovative and vulnerable nodes for therapeutic intervention.

Abstract

Roughly half of all high-risk neuroblastoma patients present with MYCN amplification. The molecular consequences of MYCN overexpression in this aggressive pediatric tumor have been studied for decades, but thus far, our understanding of the early initiating steps of MYCN-driven tumor formation is still enigmatic. We performed a detailed transcriptome landscaping during murine TH-MYCN-driven neuroblastoma tumor formation at different time points. The neuroblastoma dependency factor MEIS2, together with ASCL1, was identified as a candidate tumor-initiating factor and shown to be a novel core regulatory circuit member in adrenergic neuroblastomas. Of further interest, we found a KEOPS complex member (gm6890), implicated in homologous double-strand break repair and telomere maintenance, to be strongly upregulated during tumor formation, as well as the checkpoint adaptor Claspin (CLSPN) and three chromosome 17q loci CBX2, GJC1 and LIMD2. Finally, cross-species master regulator analysis identified FOXM1, together with additional hubs controlling transcriptome profiles of MYCN-driven neuroblastoma. In conclusion, time-resolved transcriptome analysis of early hyperplastic lesions and full-blown MYCN-driven neuroblastomas yielded novel components implicated in both tumor initiation and maintenance, providing putative novel drug targets for MYCN-driven neuroblastoma.

Abstract 2481: Time-resolved transcriptome analysis of murine TH-MYCN driven neuroblastoma identifies MEIS2 as early initiating factor and novel core gene regulatory circuitry constituent

Introduction: Neuroblastoma (NB) is a pediatric malignancy arising from peripheral neuronal sympathoblasts and exhibiting remarkable clinical and genetic heterogeneity. Patients older than 18 months have a poor prognosis with tumors presenting with highly recurrent segmental copy number alterations and MYCN amplification in half of these high-risk cases. The mechanism by which MYCN contributes to the development of neuroblastoma is unresolved and direct targeting of this key oncogene is not currently possible.

Experimental Procedures: Our discovery efforts focused on identifying cooperating interactors and vulnerabilities in the MYCN regulatory network. MYCN-driven NBs can be modeled in mice with morphologic and genomic features that recapitulate human MYCN amplified NBs. Thus, this model serves as a valid tool for cross-species genomic analysis. Using this model, we performed a time-resolved analysis of the dynamic transcriptional changes of protein coding genes during murine TH-MYCN driven neuroblastoma development, focusing on timepoints representing tumor initiation and early tumor growth. We triangulated expression changes of key genes with publicly available exome-wide CRISPR-cas9 knockout analyses on a panel of human neuroblastoma cell lines and patient survival data. This unique data resource uncovered the relevance of MEIS2 as putative early cooperating initiating factor for neuroblastoma. Analysis of the genome-wide binding profile of MEIS2 in MYCN-amplified NB cell lines showed a striking overlap with enhancer-driven gene expression in regions of open chromatin, providing evidence that MEIS2 is a novel member of the adrenergic neuroblastoma core-regulatory circuitry. CRISPR-Cas9 mediated deletion of MEIS2 in animal models suppresses establishment of neuroblastoma tumors, indicating its putative requirement for tumor initiation. MEIS2, as a member of the CRC binds to several master regulators of gene expression, including the FOXM1 locus.

Summary and conclusion: In conclusion, we present an in-depth characterization of the dynamic transcriptome profiles of TH-MYCN driven murine premalignant and established tumors and integrate with both primary human neuroblastoma tumor expression data, epigenetic and functional genomics data to identify and validate candidate cooperating dependencies suitable for targeting as a precision medicine approach in neuroblastoma.

Citation Format: Kaat Durinck, Mark Zimmerman, Nina Weichert-Leahey, Jolien Dewyn, Wouter Van Loocke, Carolina Nunes, Anneleen Beckers, Bieke Decaesteker, Pieter-Jan Volders, Christophe Van Neste, Belamy Cheung, Daniel Carter, Thomas A. Look, Glenn Marshall, Katleen De Preter, Adam Durbin, Franki Speleman. Time-resolved transcriptome analysis of murine TH-MYCN driven neuroblastoma identifies MEIS2 as early initiating factor and novel core gene regulatory circuitry constituent [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2481.

[Neuroendocrine neoplasms : a new era to the top of multidisciplinarity !]

Neuroendocrine neoplasms are histologically defined by a common neuroendocrine cellular phenotype. These are still considered as rare tumours even though their incidence is increasing. Heterogeneity is everywhere whether in the localization of the primitive cancer, the clinical presentation, the histological classification, the prognosis, as well as in therapeutic options, which clearly justifies specialized multidisciplinary care. Heterogeneity and scarcity explain the still fragmented nature of knowledge in this domain. Thanks to an increase in incidence, a desire for standardization of classification as well as the arrival of major therapeutic advances, such as vectorized internal radiotherapy, the future of neuroendocrine neoplasia seems more than promising and exciting. In our daily clinical practice at CHU Liège, we hope to bring our stone to the building by listing as many cases as possible in national and/or international databases, by centralizing therapeutic discussions within specific multidisciplinary concertations and by participating in multicenter study protocols.

Discordant biological parameters of remission in acromegaly do not increase the risk of hypertension or diabetes: a study with the Liege Acromegaly Survey database

PURPOSE

Acromegaly is a rare disease due to growth hormone (GH)-secreting pituitary adenoma. GH and IGF-1 levels are usually congruent, indicating either remission or active disease; however, a discrepancy between GH and IGF-1 may occur. We aimed to evaluate the outcome of diabetes mellitus (DM) and hypertension (HT) in acromegalic patients with congruent GH and/or IGF-1 levels vs. discordant biochemical parameters.

METHODS

Retrospective analysis of the data of 3173 patients from the Liege Acromegaly Survey (LAS) allowed us to include 190 patients from 8 tertiary referral centers across Europe, treated by surgery, with available data concerning DM and HT both at diagnosis and at the last follow-up (LFU). We recorded the number of anti-HT and anti-DM drugs used at the first evaluation and at LFU for every patient.

RESULTS

Ninety-nine patients belonged to the REM group (concordant parameters), 65 patients were considered as GH_dis (high random GH/controlled IGF-1), and 26 patients were considered as IGF-1_dis (high IGF-1/controlled random GH). At diagnosis, 72 patients (37.8%) had HT and 54 patients had DM (28.4%). There was no statistically significant difference in terms of the number of anti-HT and anti-DM drugs at diagnosis versus LFU (mean duration: 7.3 ± 4.5 years) between all three groups.

CONCLUSION

The long-term outcome of DM and HT in acromegaly does not tend to be more severe in patients with biochemical discordance in comparison with patients considered as in remission on the basis of concordant biological parameters, suggesting that patients with biochemical discordance do not require a closer follow-up.

Plasma miRNAs as biomarkers for endometriosis

STUDY QUESTION

Can plasma miRNAs be used for the non-invasive diagnosis of endometriosis in infertile women?

SUMMARY ANSWER

miRNA-based diagnostic models for endometriosis failed the test of independent validation.

WHAT IS KNOWN ALREADY

Circulating miRNAs have been described to be differentially expressed in patients with endometriosis compared with women without endometriosis, suggesting that they could be used for the non-invasive diagnosis of endometriosis. However, these studies have shown limited consistency or conflicting results, and no miRNA-based diagnostic test has been validated in an independent patient cohort.

STUDY DESIGN, SIZE, DURATION

We performed genome-wide miRNA expression profiling by small RNA sequencing to identify a set of plasma miRNAs with discriminative potential between patients with and without endometriosis. Expression of this set of miRNAs was confirmed by RT-qPCR. Diagnostic models were built using multivariate logistic regression with stepwise feature selection. In a final step, the models were tested for validation in an independent patient cohort.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

Plasma of all patients was available in the biobank of the Leuven Endometriosis Centre of Excellence. Biomarker discovery and model development were performed in a discovery cohort of 120 patients (controls = 38, endometriosis = 82), and models were tested for validation in an independent cohort of 90 patients (controls = 30, endometriosis = 60). RNA was extracted with the miRNeasy Plasma Kit. Genome-wide miRNA expression analysis was done by small RNA sequencing using the NEBNext small RNA library prep kit and the NextSeq 500 System. cDNA synthesis and qPCR were performed using the Qiagen miScript technology.

MAIN RESULTS AND THE ROLE OF CHANCE

We identified a set of 42 miRNAs with discriminative power between patients with and without endometriosis based on genome-wide miRNA expression profiling. Expression of 41 miRNAs was confirmed by RT-qPCR, and 3 diagnostic models were built. Only the model for minimal-mild endometriosis (Model 2: hsa-miR-125b-5p, hsa-miR-28-5p and hsa-miR-29a-3p) had diagnostic power above chance performance in the independent validation (AUC = 60%) with an acceptable sensitivity (78%) but poor specificity (37%).

LIMITATIONS, REASONS FOR CAUTION

The diagnostic models were built and tested for validation in two patient cohorts from a single tertiary endometriosis centre. Further validation tests in large cohorts with patients from multiple endometriosis centres are needed.

WIDER IMPLICATION OF THE FINDINGS

Our study supports a possible biological link between certain miRNAs and endometriosis, but the potential of these miRNAs as clinically useful biomarkers is questionable in women with infertility. Large studies in well-described patient cohorts, with rigorous methodology for miRNA expression analysis, sufficient statistical power and an independent validation step, are necessary to answer the question of whether miRNAs can be used as diagnostics markers for endometriosis.

STUDY FUNDING/COMPETING INTEREST(S)

The project was funded by a grant from the Research Foundation - Flanders (FWO). A.V., D.F.O. and D.P. are PhD fellows from the FWO. T.D. is vice president and Head of Global Medical Affairs Fertility, Research and Development, Merck KGaA, Darmstadt, Germany. He is also a professor in Reproductive Medicine and Biology at the Department of Development and Regeneration, Group Biomedical Sciences, KU Leuven (University of Leuven), Belgium and an adjunct professor at the Department of Obstetrics and Gynecology in the University of Yale, New Haven, USA. Neither his corporate role nor his academic roles represent a conflict of interest with respect to the work done by him for this study. The other co-authors have no conflict of interest.

TRIAL REGISTRATION NUMBER

Not applicable.

[Polycystic ovary syndrome : the advantages of multidisciplinary management]

The polycystic ovary syndrome is one of the most frequent endocrine disorders in women of reproductive age. The first signs and symptoms of the disease may be present as early as puberty. Diagnostic criteria include hyperandrogenism (clinical or biological), ovulatory dysfunction and polycystic ovarian morphology on ultrasound. The consequences of the syndrome are multiple. These consist of fertility issues and metabolic anomalies with increased cardiovascular risk, but also sleep disturbances, increased risk of endometrial hyperplasia and endometrial cancer and a potentially important psychological impact with decreased quality of life. The management of polycystic ovary syndrome is multidisciplinary and treatment is variable, depending on symptoms and the patient's desire for fertility. In all cases, measures aiming to improve the metabolic dysfunction are essential, going from adopting a healthy lifestyle to adequate therapy of each metabolic anomaly.

Neuroimaging of aggressive pituitary tumors

Aggresssive pituitary tumors are defined as radiologically invasive, exhibiting a rapid growth and a poor response to the medical and surgical treatment options. The role of magnetic resonance imaging (MRI) is fundamental to assess tumor aggressiveness before surgical exploration. Distinction between cavernous sinus invasion and cavernous sinus compression is often challenging and cannot be solved always by using the Knosp criteria. Ideally, T2W images demonstrating the ruptured internal dural wall of cavernous sinus is the ultimate proof of cavernous sinus invasion. Subtle tumor volume increase in a short time can be shown when sequential MR images are rigorously replicable. A microcystic pattern observed on T2W images frequently reflects a potentially aggressive tumor as observed in silent corticotroph pituitary adenomas.

The role of AIP variants in pituitary adenomas and concomitant thyroid carcinomas in the Netherlands: a nationwide pathology registry (PALGA) study

PURPOSE

Germline mutations in the aryl-hydrocarbon receptor interacting protein (AIP) have been identified often in the setting of familial isolated pituitary adenoma (FIPA). To date there is no strong evidence linking germline AIP mutations to other neoplasms apart from the pituitary. Our primary objective was to investigate the prevalence of AIP gene mutations and mutations in genes that have been associated with neuroendocrine tumors in series of tumors from patients presenting with both pituitary adenomas and differentiated thyroid carcinomas (DTCs).

METHODS

Pathology samples were retrieved from all pituitary adenomas in patients with concomitant DTCs, including one with a known germline AIP variant. Subsequently, two additional patients with known germline AIP variants were included, of which one presented only with a follicular thyroid carcinoma (FTC).

RESULTS

In total, 17 patients (14 DTCs and 15 pituitary adenomas) were investigated by targeted next generation sequencing (NGS). The pituitary tumor samples revealed no mutations, while among the thyroid tumor samples BRAF (6/14, 42.9%) was the most frequently mutated gene, followed by NRAS (3/11, 27.3%). In one AIP-mutated FIPA kindred, the AIP-variant c.853C>T; p.Q285* was confirmed in the FTC specimen, including evidence of loss of heterozygosity (LOH) at the AIP locus in the tumor DNA.

CONCLUSION

Although most observed variants in pituitary adenomas and DTCs were similar to those of sporadic DTCs, we confirmed in one AIP mutation-positive case the AIP-variant and LOH at this locus in an FTC specimen, which raises the potential role of the AIP mutation as a rare initiating event.

Acromegaly in the setting of Tatton-Brown-Rahman Syndrome

PURPOSE

Tatton-Brown-Rahman syndrome (TBRS) is a newly defined genetic entity characterized by overgrowth and intellectual disability, resulting from germline mutations in the gene encoding DNA methyltransferase 3 alpha (DNMT3A). Affected individuals with benign and malignant tumors have been reported; to our knowledge pituitary adenomas (and other tumors identified in our patient) have not yet been described in this syndrome.

CASE

We report the case of a 34-year-old woman with TBRS who developed a GH-secreting pituitary macroadenoma and other benign tumors and cystic lesions involving diverse organ systems. Whole-exome sequencing revealed a heterozygous, likely pathogenic variant (c.700_709 del10, p. Gly234ArgfsX79) in exon7 of DNMT3A, and a heterozygous variant of uncertain significance (c.25 C>T, p.Arg9Trp) in exon 1 of the gene encoding aryl hydrocarbon receptor-interacting protein (AIP). The patient failed somatostatin analog treatment, and underwent surgery. The tumor retained AIP expression, and analysis of tumor DNA indicated the presence of both AIP alleles, consistent with no loss of heterozygosity. These findings suggest that the AIP variant was not the primary driver of pituitary adenoma development.

CONCLUSION

Our case suggests that TBRS might be associated with pituitary adenoma and a broader spectrum of tumors than previously thought, making long-term follow up of these patients crucial to identify tumors early, and to elucidate the clinical spectrum of the disorder for optimization of management.

[Clinical zoanthropy: a woman with the rare delusion of being an animal]

Clinical zoanthropy, or the conviction of having turned into an animal, is a rare delusion. There are different views about its pathogenesis. This delusion can occur with an underlying psychiatric disorder, but it can also be secondary to structural or functional disorders of the brain. Additional investigations with brain imaging and electroencephalogram are therefore advised. Treatment for the underlying disorder is recommended. In this case report we describe a 54-year-old woman who was briefly convinced she was a chicken, followed by a generalized seizure. We discuss the epidemiology, theories about pathogenesis and treatment advice for clinical zoanthropy. We also discuss the possible relevance of epilepsy to this matter. With this case report, we hope to contribute to documenting this rare, but possibly underreported phenomenon.

[Endocrine consequences of immune checkpoint inhibitors]

Immune checkpoints inhibitors have fundamentally changed the management of oncologic patients. These treatments consist of monoclonal antibodies directed against CTLA-4 (cytotoxic T-lymphocyte antigen 4), PD-1 (programmed cell death protein-1) and PD-L1 (one of its ligands). By blocking these receptors or ligands, the antibodies reverse the immune tolerance induced by the cancerous cell on the T-lymphocyte and favour lymphocytic reactivation and anti-tumor activity. Immune tolerance to auto-antigens is maintained with the help of these checkpoints. Targeting them can lead to auto-immune side effects. These latter mostly impact the cutaneous and digestive system, but the endocrine glands are not spared. In this article, we provide monitoring and treatment algorithms for these endocrine immune side effects. An early diagnosis followed by the appropriate treatment would reduce their negative impact on the oncologic care.

[Chronic autoimmune gastritis : a multidisciplinary management]

Chronic autoimmune gastritis (CAG) is a continuum of histological changes in gastric mucosa including: atrophy, intestinal metaplasia, dysplasia and finally, the occurrence of a neoplasm (gastric Neuroendocrine Tumors -NETs- and adenocarcinoma). The association with Hashimoto and Graves-Basedow disease is known as the thyrogastric autoimmune syndrome. While Helicobacter pylori (Hp) infection may be associated with CAG, the role of the gastric microbiota is ill-defined. The gastric hypochlorhydria determines a malabsorption of different micronutrients (iron, magnesium, calcium, vitamin B12) as well as drugs (thyroxine, etc.). Pernicious anemia is favoured by the deficit of parietal intrinsic factor that contributes to B12 malabsorption. Serology for Hp, serum pepsinogen I/II, increased gastrin levels, the presence of parietal cell antibodies and intrinsic factor antibodies may reveal CAG. High definition endoscopy associated with virtual chromoendoscopy seems promising for CAG diagnosis and follow-up. NETs type 1 treatment includes: endoscopic and surgical resection, somatostatin analogues and the recent availability of netazepide, a gastrin antagonist. We review herein advances in the treatment and diagnosis of CAG and associated autoimmune disorders, which may involve, in a multidisciplinary way, all practitioners.

Discovery and validation of a serum microRNA signature to characterize oligo- and polymetastatic prostate cancer: not ready for prime time

PURPOSE

Patients with oligometastatic prostate cancer (PC) may benefit from metastasis-directed therapy (MDT), delaying disease progression and the start of palliative systemic treatment. However, a significant proportion of oligometastatic PC patients progress to polymetastatic PC within a year following MDT, suggesting an underestimation of the metastatic load by current staging modalities. Molecular markers could help to identify true oligometastatic patients eligible for MDT.

METHODS

Patients with asymptomatic biochemical recurrence following primary PC treatment were classified as oligo- or polymetastatic based on 18^F-choline PET/CT imaging. Oligometastatic patients had up to three metastases at baseline and did not progress to more than three lesions following MDT or surveillance within 1 year of diagnosis of metastases. Polymetastatic patients had > 3 metastases at baseline or developed > 3 metastases within 1 year following imaging. A model aiming to prospectively distinguish oligo- and polymetastatic PC patients was trained using clinicopathological parameters and serum-derived microRNA expression profiles from a discovery cohort of 20 oligometastatic and 20 polymetastatic PC patients. To confirm the models predictive performance, it was applied on biomarker data obtained from an independent validation cohort of 44 patients with oligometastatic and 39 patients with polymetastatic disease.

RESULTS

Oligometastatic PC patients had a more favorable prognosis compared to polymetastatic ones, as defined by a significantly longer median CRPC-free survival (not reached versus 38 months; 95% confidence interval 31-45 months with P < 0.001). Despite the good performance of a predictive model trained on the discovery cohort, with an AUC of 0.833 (0.693-0.973; 95% CI) and a sensitivity of 0.894 (0.714-1.000; 95% CI) for oligometastatic disease, none of the miRNA targets were found to be differentially expressed between oligo- and polymetastatic PC patients in the signature validation cohort. The multivariate model had an AUC of 0.393 (0.534 after cross-validation) and therefore, no predictive ability.

CONCLUSIONS

Although PC patients with oligometastatic disease had a more favorable prognosis, no serum-derived biomarkers allowing for prospective discrimination of oligo- and polymetastatic prostate cancer patients could be identified.

[Cushing's syndrome during pregnancy : diagnostic and therapeutic difficulties]

Cushing's syndrome (CS), which is often associated with infertility, exceptionally occurs in pregnancy, and markedly increases maternal and fetal morbidity and mortality. Gestational CS may be challenging. Indeed, symptoms of hypercorticism may overlap with physiological hyperactivity of the hypothalamus-pituitary-adrenal axis in normal pregnancy. This case report describes a pregnant patient that underwent a fertility treatment and developed a gestational CS due to an adrenocortical adenoma. Diagnosis of gestational CS was suspected at 13 weeks by a new onset of hypokalemia and arterial hypertension. A multidisciplinary approach was necessary during follow up. At 24 weeks, laparoscopic surgery retrieved a 4 cm adrenocortical adenoma. Cesarean surgery was successfully practiced at 31 weeks, because of preeclampsia. We discuss the differential diagnosis of hypokalemia and arterial hypertension during pregnancy and the diagnosis and management of gestational CS.

[A brief history of syphilis. The disease through the art and the artist]

Considering its strong symbolic connotations and its rich history, syphilis could be regarded as the perfect example of venerian disease. It could also be seen as a representative disease of the whole medical history and the evolution of both medical ways of thinking and curing. In this work we will briefly discuss the history of the syphilitic disease and try to show how this condition has affected the life and works of some of the most famous artists of the 19th century. Moreover, we shall try to evoke the complex relationship between art and pathology.

Network Modeling of microRNA-mRNA Interactions in Neuroblastoma Tumorigenesis Identifies miR-204 as a Direct Inhibitor of MYCN

Neuroblastoma is a pediatric cancer of the sympathetic nervous system where MYCN amplification is a key indicator of poor prognosis. However, mechanisms by which MYCN promotes neuroblastoma tumorigenesis are not fully understood. In this study, we analyzed global miRNA and mRNA expression profiles of tissues at different stages of tumorigenesis from TH-MYCN transgenic mice, a model of MYCN-driven neuroblastoma. On the basis of a Bayesian learning network model in which we compared pretumor ganglia from TH-MYCN^+/+ mice to age-matched wild-type controls, we devised a predicted miRNA-mRNA interaction network. Among the miRNA-mRNA interactions operating during human neuroblastoma tumorigenesis, we identified miR-204 as a tumor suppressor miRNA that inhibited a subnetwork of oncogenes strongly associated with MYCN-amplified neuroblastoma and poor patient outcome. MYCN bound to the miR-204 promoter and repressed miR-204 transcription. Conversely, miR-204 directly bound MYCN mRNA and repressed MYCN expression. miR-204 overexpression significantly inhibited neuroblastoma cell proliferation in vitro and tumorigenesis in vivo Together, these findings identify novel tumorigenic miRNA gene networks and miR-204 as a tumor suppressor that regulates MYCN expression in neuroblastoma tumorigenesis.Significance: Network modeling of miRNA-mRNA regulatory interactions in a mouse model of neuroblastoma identifies miR-204 as a tumor suppressor and negative regulator of MYCN. Cancer Res; 78(12); 3122-34. ©2018 AACR.

Targeting tachykinin receptors in neuroblastoma

Neuroblastoma is the most common extracranial tumor in children. Despite aggressive multimodal treatment, high-risk neuroblastoma remains a clinical challenge with survival rates below 50%. Adding targeted drugs to first-line therapy regimens is a promising approach to improve survival in these patients. TACR1 activation by substance P has been reported to be mitogenic in cancer cell lines. Tachykinin receptor (TACR1) antagonists are approved for clinical use as an antiemetic remedy since 2003. Tachykinin receptor inhibition has recently been shown to effectively reduce growth of several tumor types. Here, we report that neuroblastoma cell lines express TACR1, and that targeting TACR1 activity significantly reduced cell viability and induced apoptosis in neuroblastoma cell lines. Gene expression profiling revealed that TACR1 inhibition repressed E2F2 and induced TP53 signaling. Treating mice harboring established neuroblastoma xenograft tumors with Aprepitant also significantly reduced tumor burden. Thus, we provide evidence that the targeted inhibition of tachykinin receptor signaling shows therapeutic efficacy in preclinical models for high-risk neuroblastoma.

The mutational landscape of MYCN, Lin28b and ALKF1174L driven murine neuroblastoma mimics human disease

Genetically engineered mouse models have proven to be essential tools for unraveling fundamental aspects of cancer biology and for testing novel therapeutic strategies. To optimally serve these goals, it is essential that the mouse model faithfully recapitulates the human disease. Recently, novel mouse models for neuroblastoma have been developed. Here, we report on the further genomic characterization through exome sequencing and DNA copy number analysis of four of the currently available murine neuroblastoma model systems (ALK, Th-MYCN, Dbh-MYCN and Lin28b). The murine tumors revealed a low number of genomic alterations – in keeping with human neuroblastoma - and a positive correlation of the number of genetic lesions with the time to onset of tumor formation was observed. Gene copy number alterations are the hallmark of both murine and human disease and frequently affect syntenic genomic regions. Despite low mutational load, the genes mutated in murine disease were found to be enriched for genes mutated in human disease. Taken together, our study further supports the validity of the tested mouse models for mechanistic and preclinical studies of human neuroblastoma.

Model-Based Classification for Digital PCR: Your Umbrella for Rain

Standard data analysis pipelines for digital PCR estimate the concentration of a target nucleic acid by digitizing the end-point fluorescence of the parallel micro-PCR reactions, using an automated hard threshold. While it is known that misclassification has a major impact on the concentration estimate and substantially reduces accuracy, the uncertainty of this classification is typically ignored. We introduce a model-based clustering method to estimate the probability that the target is present (absent) in a partition conditional on its observed fluorescence and the distributional shape in no-template control samples. This methodology acknowledges the inherent uncertainty of the classification and provides a natural measure of precision, both at individual partition level and at the level of the global concentration. We illustrate our method on genetically modified organism, inhibition, dynamic range, and mutation detection experiments. We show that our method provides concentration estimates of similar accuracy or better than the current standard, along with a more realistic measure of precision. The individual partition probabilities and diagnostic density plots further allow for some quality control. An R implementation of our method, called Umbrella, is available, providing a more objective and automated data analysis procedure for absolute dPCR quantification.

A multivariable prediction model for pegvisomant dosing: monotherapy and in combination with long-acting somatostatin analogues

BACKGROUND

Effective treatment of acromegaly with pegvisomant (PEGV), a growth hormone receptor antagonist, requires an appropriate dose titration. PEGV doses vary widely among individual patients, and various covariates may affect its dosing and pharmacokinetics.

OBJECTIVE

To identify predictors of the PEGV dose required to normalize insulin-like growth factor I (IGF-I) levels during PEGV monotherapy and in combination with long-acting somatostatin analogues (LA-SSAs).

DESIGN

Two retrospective cohorts (Rotterdam + Liège Acromegaly Survey (LAS), total n = 188) were meta-analyzed as a form of external replication to study the predictors of PEGV dosing in addition to LA-SSA, the LAS (n = 83) was used to study the predictors of PEGV monotherapy dosing. Multivariable regression models were used to identify predictors of the PEGV dose required to normalize IGF-I levels.

RESULTS

For PEGV dosing in combination with LA-SSA, IGF-I levels, weight, height and age, were associated with the PEGV normalization dosage (P ≤ 0.001, P ≤ 0.001, P = 0.028 and P = 0.047 respectively). Taken together, these characteristics predicted the PEGV normalization dose correctly in 63.3% of all patients within a range of ±60 mg/week (21.3% within a range of ±20 mg/week). For monotherapy, only weight was associated with the PEGV normalization dose (P ≤ 0.001) and predicted this dosage correctly in 77.1% of all patients within a range of ±60 mg/week (31.3% within a range of ±20 mg/week).

CONCLUSION

In this study, we show that IGF-I levels, weight, height and age can contribute to define the optimal PEGV dose to normalize IGF-I levels in addition to LA-SSA. For PEGV monotherapy, only the patient's weight was associated with the IGF-I normalization PEGV dosage.

Cabergoline for Cushing's disease: a large retrospective multicenter study

OBJECTIVE

The efficacy of cabergoline in Cushing's disease (CD) is controversial. The aim of this study was to assess the efficacy and tolerability of cabergoline in a large contemporary cohort of patients with CD.

DESIGN

We conducted a retrospective multicenter study from thirteen French and Belgian university hospitals.

METHODS

Sixty-two patients with CD received cabergoline monotherapy or add-on therapy. Symptom score, biological markers of hypercortisolism and adverse effects were recorded.

RESULTS

Twenty-one (40%) of 53 patients who received cabergoline monotherapy had normal urinary free cortisol (UFC) values within 12 months (complete responders), and five of these patients developed corticotropic insufficiency. The fall in UFC was associated with significant reductions in midnight cortisol and plasma ACTH, and with clinical improvement. Compared to other patients, complete responders had similar median baseline UFC (2.0 vs 2.5xULN) and plasma prolactin concentrations but received lower doses of cabergoline (1.5 vs 3.5 mg/week, P < 0.05). During long-term treatment (>12 months), cabergoline was withdrawn in 28% of complete responders because of treatment escape or intolerance. Overall, sustained control of hypercortisolism was obtained in 23% of patients for 32.5 months (19-105). Nine patients on steroidogenesis inhibitors received cabergoline add-on therapy for 19 months (1-240). Hypercortisolism was controlled in 56% of these patients during the first year of treatment with cabergoline at 1.0 mg/week (0.5-3.5).

CONCLUSIONS

About 20-25% of CD patients are good responders to cabergoline therapy allowing long-term control of hypercortisolism at relatively low dosages and with acceptable tolerability. No single parameter, including the baseline UFC and prolactin levels, predicted the response to cabergoline.

MRI follow-up is unnecessary in patients with macroprolactinomas and long-term normal prolactin levels on dopamine agonist treatment

OBJECTIVE

Both antitumor and antisecretory efficacies of dopamine agonists (DA) make them the first-line treatment of macroprolactinomas. However, there is no guideline for MRI follow-up once prolactin is controlled. The aim of our study was to determine whether a regular MRI follow-up was necessary in patients with long-term normal prolactin levels under DA.

PATIENTS AND METHODS

We conducted a retrospective multicenter study (Marseille, Paris La Pitie Salpetriere and Nancy, France; Liege, Belgium) including patients with macroprolactinomas (largest diameter: >10 mm and baseline prolactin level: >100 ng/mL) treated by dopamine agonists, and regularly followed (pituitary MRI and prolactin levels) during at least 48 months once normal prolactin level was obtained.

RESULTS

In total, 115 patients were included (63 men and 52 women; mean age at diagnosis: 36.3 years). Mean baseline prolactin level was 2224 ± 6839 ng/mL. No significant increase of tumor volume was observed during the follow-up. Of the 21 patients (18%) who presented asymptomatic hemorrhagic changes of the macroprolactinoma on MRI, 2 had a tumor increase (2 and 7 mm in the largest size). Both were treated by cabergoline (1 mg/week) with normal prolactin levels obtained for 6 and 24 months. For both patients, no further growth was observed on MRI during follow-up at the same dose of cabergoline.

CONCLUSION

No significant increase of tumor size was observed in our patients with controlled prolactin levels on DA. MRI follow-up thus appears unnecessary in patients with biologically controlled macroprolactinomas.

[A Familial Non Medullary Thyroid Carcinoma (FNMTC) : a clinical and genetic update]

The syndrome of Familial Non Medullary Thyroid Carcinoma (FNMTC) includes two or more patients with an isolated non-medullary thyroid cancer (papillary, follicular, anaplastic) within the same family. To diagnose FNMTC, the clinician must exclude a syndromic presentation such as the syndromes of Cowden, Gardner or Werner, and the Carney Complex. Up to now, a hundred families with FNMTC have been genetically studied, including forms with (Ch19p13.2) or without oxyphilia (Ch2q21), in association with a multinodular goiter (Ch14q32), or with a renal cancer (Ch1q21). Several candidate genes of susceptibility have been proposed: SRGAP1, NKX2-1, FOXE1 and HABP2. So far, it is considered that familial cases represent less than 5 % of thyroid cancers. Although rare, these cases represent a unique opportunity to improve our understanding of thyroid cancer. The identification of candidate genes will enrich our knowledge of thyroid cancer pathophysiology. Based on the literature and our experience of the follow-up of eight families with FNMTC, we discuss epidemiological, clinical, pathological and genetic aspects of FNMTC with a view to improve the diagnosis and treatment of this disease.

Therapeutic targeting of the MYC signal by inhibition of histone chaperone FACT in neuroblastoma

Amplification of the MYCN oncogene predicts treatment resistance in childhood neuroblastoma. We used a MYC target gene signature that predicts poor neuroblastoma prognosis to identify the histone chaperone FACT (facilitates chromatin transcription) as a crucial mediator of the MYC signal and a therapeutic target in the disease. FACT and MYCN expression created a forward feedback loop in neuroblastoma cells that was essential for maintaining mutual high expression. FACT inhibition by the small-molecule curaxin compound CBL0137 markedly reduced tumor initiation and progression in vivo. CBL0137 exhibited strong synergy with standard chemotherapy by blocking repair of DNA damage caused by genotoxic drugs, thus creating a synthetic lethal environment in MYCN-amplified neuroblastoma cells and suggesting a treatment strategy for MYCN-driven neuroblastoma.

GPR101 Mutations are not a Frequent Cause of Congenital Isolated Growth Hormone Deficiency

Patients with Xq26.3 microduplication present with X-linked acrogigantism (X-LAG) syndrome, an early-childhood form of gigantism due to marked growth hormone (GH) hypersecretion from mixed GH-PRL adenomas and hyperplasia. The microduplication includes GPR101, which is upregulated in patients' tumor tissue. The GPR101 gene codes for an orphan G protein coupled receptor that is normally highly expressed in the hypothalamus. Our aim was to determine whether GPR101 loss of function mutations or deletions could be involved in patients with congenital isolated GH deficiency (GHD). Taking advantage of the cohort of patients from the GENHYPOPIT network, we studied 41 patients with unexplained isolated GHD. All patients had Sanger sequencing of the GPR101 gene and array comparative genome hybridization (aCGH) to look for deletions. Functional studies (cell culture with GH secretion measurements, cAMP response) were performed. One novel GPR101 variant, c.589 G>T (p.V197L), was seen in the heterozygous state in a patient with isolated GHD. In silico analysis suggested that this variant could be deleterious. Functional studies did not show any significant difference in comparison with wild type for GH secretion and cAMP response. No truncating, frameshift, or small insertion-deletion (indel) GPR101 mutations were seen in the 41 patients. No deletion or other copy number variation at chromosome Xq26.3 was found on aCGH. We found a novel GPR101 variant of unknown significance, in a patient with isolated GH deficiency. Our study did not identify GPR101 abnormalities as a frequent cause of GH deficiency.

Persistent low levels of serum hCG due to heterophilic mouse antibodies: an unrecognized pitfall in the diagnosis of trophoblastic disease

Phantom hCG refers to persistent mild elevations of hCG, leading physicians to unnecessary treatments whereas neither a true hCG nor a trophoblastic disease is present. We report the case of a 23-year-old woman with persistent low levels of serum hCG detected one month after miscarriage. As choriocarcinoma was suspected, a chemotherapy trial of methotrexate was prescribed, without any hCG reduction. Subsequently, laparoscopy ruled out a trophoblastic residue and the patient was referred to the Endocrine Unit for further investigations. While low levels of hCG were still detected in serum, no hCG was detected in the urine. In addition, when serum was processed in a HBT tube for revealing heterophilic antibodies, hCG was no longer detected. Such finding indicated the presence of phantom hCG due to heterophilic mouse antibodies interaction. This case raises the need of clinico-biological discussion to avoid inappropriate therapeutic decisions. Based on this case experience and after review of the literature, we suggest that current gynecological protocols for the diagnosis and treatment of trophoblastic disease should consider the inclusion of urinary hCG and/or a test for serum heterophilic antibodies when appropriate.

Targeting MYCN-Driven Transcription By BET-Bromodomain Inhibition

PURPOSE

Targeting BET proteins was previously shown to have specific antitumoral efficacy against MYCN-amplified neuroblastoma. We here assess the therapeutic efficacy of the BET inhibitor, OTX015, in preclinical neuroblastoma models and extend the knowledge on the role of BRD4 in MYCN-driven neuroblastoma.

EXPERIMENTAL DESIGN

The efficacy of OTX015 was assessed in in vitro and in vivo models of human and murine MYCN-driven neuroblastoma. To study the effects of BET inhibition in the context of high MYCN levels, MYCN was ectopically expressed in human and murine cells. The effect of OTX015 on BRD4-regulated transcriptional pause release was analyzed using BRD4 and H3K27Ac chromatin immunoprecipitation coupled with DNA sequencing (ChIP-Seq) and gene expression analysis in neuroblastoma cells treated with OTX015 compared with vehicle control.

RESULTS

OTX015 showed therapeutic efficacy against preclinical MYCN-driven neuroblastoma models. Similar to previously described BET inhibitors, concurrent MYCN repression was observed in OTX015-treated samples. Ectopic MYCN expression, however, did not abrogate effects of OTX015, indicating that MYCN repression is not the only target of BET proteins in neuroblastoma. When MYCN was ectopically expressed, BET inhibition still disrupted MYCN target gene transcription without affecting MYCN expression. We found that BRD4 binds to super-enhancers and MYCN target genes, and that OTX015 specifically disrupts BRD4 binding and transcription of these genes.

CONCLUSIONS

We show that OTX015 is effective against mouse and human MYCN-driven tumor models and that BRD4 not only targets MYCN, but specifically occupies MYCN target gene enhancers as well as other genes associated with super-enhancers. Clin Cancer Res; 22(10); 2470-81. ©2015 AACR.

RNA expression signatures and posttranscriptional regulation in diabetic nephropathy

In the last decade, the integration of molecular approaches including transcriptome and miRNome analyses uncovered pathological mechanisms involved in the progression of diabetic nephropathy (DN). Using these techniques, molecular marker candidates [both messenger RNA (mRNA) and miRNA] have also been identified which may enable the characterization of patients at high risk for progression to end-stage renal disease. The results of such studies are urgently needed for a molecular definition of DN and for targeted treatment to improve patient care. The heterogeneity of kidney tissue and the minute amounts of RNA isolated from renal biopsies remain a challenge for omics-studies. Nevertheless, several studies have succeeded in the identification of RNA expression signatures in patients with diabetes and kidney disease. These studies show a reduced expression of growth factors such as VEGF and EGF, and an increased expression of matrix components and matrix-modulating enzymes, an activation of specific NF-κB modules, inflammatory pathways and the complement system. microRNAs are involved in the fine-tuning of mRNA abundance by binding to the 3' untranslated region of a target mRNA, which leads in most cases to translational repression or mRNA cleavage and a decrease in protein output. Here, we review the platforms used for miRNA expression profiling and ways to predict miRNA targets and functions. Several miRNAs have been shown to be involved in the pathogenesis of DN (e.g. miR-21, miR-192, miR-215, miR-216a, miR-29, let-7, miR-25, miR-93, etc.). Functional studies provide evidence that miRNAs are not only diagnostic tools but also represent potential therapeutic targets in DN.

Glutathione biosynthesis is upregulated at the initiation of MYCN-driven neuroblastoma tumorigenesis

The MYCN gene is amplified and overexpressed in a large proportion of high stage neuroblastoma patients and has been identified as a key driver of tumorigenesis. However, the mechanism by which MYCN promotes tumor initiation is poorly understood. Here we conducted metabolic profiling of pre-malignant sympathetic ganglia and tumors derived from the TH-MYCN mouse model of neuroblastoma, compared to non-malignant ganglia from wildtype littermates. We found that metabolites involved in the biosynthesis of glutathione, the most abundant cellular antioxidant, were the most significantly upregulated metabolic pathway at tumor initiation, and progressively increased to meet the demands of tumorigenesis. A corresponding increase in the expression of genes involved in ribosomal biogenesis suggested that MYCN-driven transactivation of the protein biosynthetic machinery generated the necessary substrates to drive glutathione biosynthesis. Pre-malignant sympathetic ganglia from TH-MYCN mice had higher antioxidant capacity and required glutathione upregulation for cell survival, when compared to wildtype ganglia. Moreover, in vivo administration of inhibitors of glutathione biosynthesis significantly delayed tumorigenesis when administered prophylactically and potentiated the anticancer activity of cytotoxic chemotherapy against established tumors. Together these results identify enhanced glutathione biosynthesis as a selective metabolic adaptation required for initiation of MYCN-driven neuroblastoma, and suggest that glutathione-targeted agents may be used as a potential preventative strategy, or as an adjuvant to existing chemotherapies in established disease.

MYCN-targeting miRNAs are predominantly downregulated during MYCN‑driven neuroblastoma tumor formation

MYCN is a transcription factor that plays key roles in both normal development and cancer. In neuroblastoma, MYCN acts as a major oncogenic driver through pleiotropic effects regulated by multiple protein encoding genes as well as microRNAs (miRNAs). MYCN activity is tightly controlled at the level of transcription and protein stability through various mechanisms. Like most genes, MYCN is further controlled by miRNAs, but the full complement of all miRNAs implicated in this process has not been determined through an unbiased approach. To elucidate the role of miRNAs in regulation of MYCN, we thus explored the MYCN-miRNA interactome to establish miRNAs controlling MYCN expression levels. We combined results from an unbiased and genome-wide high-throughput miRNA target reporter screen with miRNA and mRNA expression data from patients and a murine neuroblastoma progression model. We identified 29 miRNAs targeting MYCN, of which 12 miRNAs are inversely correlated with MYCN expression or activity in neuroblastoma tumor tissue. The majority of MYCN-targeting miRNAs in neuroblastoma showed a decrease in expression during murine MYCN-driven neuroblastoma tumor development. Therefore, we provide evidence that MYCN-targeting miRNAs are preferentially downregulated in MYCN-driven neuroblastoma, suggesting that MYCN negatively controls the expression of these miRNAs, to safeguard its expression.

[CONTROVERSIES REGARDING THE ACCURACY AND LIMITATIONS OF FROZEN SECTION IN THYROID PATHOLOGY: AN EVIDENCE-BASED ASSESSMENT]

Palpable thyroid nodules are present clinically in 4-7% of the population and their prevalence increases to 50%-67% when using high-resolution neck ultrasonography. By contrast, thyroid carcinoma (TC) represents only 5-20% of these nodules, which underlines the need for an appropriate approach to avoid unnecessary surgery. Frozen section (PS) has been used for more than 40 years in thyroid surgery to establish the diagnosis of malignancy. However, a controversy persists regarding the accuracy of FS and its place in thyroid pathology has changed with the emergence of fine-needle aspiration (FNA). A PubMed Medline and SpringerLink search was made covering the period from January 2000 to June 2012 to assess the accuracy of ES, its limitations and indications for the diagnosis of thyroid nodules. Twenty publications encompassing 8.567 subjects were included in our study. The average value of TC among thyroid nodules in analyzed studies was 15.5 %. ES ability to detect cancer expressed by its sensitivity (Ss) was 67.5 %. More than two thirds of the authors considered PS useful exclusively in the presence of doubtful ENA and for guiding the surgical extension in cases confirmed as malignant by FNA; however, only 33% accepted FS as a routine examination for the management of thyroid nodules. The influence of FS on surgical reintervention rate in nodular thyroid pathology was considered to be negligible by most studies, whereas 31 % of the authors thought that FS has a favorable benefit by decreasing the number of surgical re-interventions. In conclusion, the role of FS in thyroid pathology evolved from a mandatory component for thyroid surgery to an optional examination after a pre-operative FNA cytology. The accuracy of FS seems to provide no sufficient additional benefit and most experts support its use only in the presence of equivocal or suspicious cytological features, for guiding the surgical extension in cases confirmed as malignant by FNA and for the identification of other potentially confusing intraoperative findings.

Unraveling the intrafamilial correlations and heritability of tumor types in MEN1: a Groupe d'étude des Tumeurs Endocrines study

BACKGROUND

MEN1, which is secondary to the mutation of the MEN1 gene, is a rare autosomal-dominant disease that predisposes mutation carriers to endocrine tumors. Most studies demonstrated the absence of direct genotype-phenotype correlations. The existence of a higher risk of death in the Groupe d'étude des Tumeurs Endocrines-cohort associated with a mutation in the JunD interacting domain suggests heterogeneity across families in disease expressivity. This study aims to assess the existence of modifying genetic factors by estimating the intrafamilial correlations and heritability of the six main tumor types in MEN1.

METHODS

The study included 797 patients from 265 kindred and studied seven phenotypic criteria: parathyroid and pancreatic neuroendocrine tumors (NETs) and pituitary, adrenal, bronchial, and thymic (thNET) tumors and the presence of metastasis. Intrafamilial correlations and heritability estimates were calculated from family tree data using specific validated statistical analysis software.

RESULTS

Intrafamilial correlations were significant and decreased along parental degrees distance for pituitary, adrenal and thNETs. The heritability of these three tumor types was consistently strong and significant with 64% (s.e.m.=0.13; P<0.001) for pituitary tumor, 65% (s.e.m.=0.21; P<0.001) for adrenal tumors, and 97% (s.e.m.=0.41; P=0.006) for thNETs.

CONCLUSION

The present study shows the existence of modifying genetic factors for thymus, adrenal, and pituitary MEN1 tumor types. The identification of at-risk subgroups of individuals within cohorts is the first step toward personalization of care. Next generation sequencing on this subset of tumors will help identify the molecular basis of MEN1 variable genetic expressivity.

[Light pollution. A connection between ecology and health]

Light pollution is defined as the abnormal and disturbing nocturnal presence of light, its adverse consequences on flora, fauna, and, ecosystems, and its suspected or proven effects on human health. Light pollution is a quite recent and increasing phenomenon within our society; it leads to a major environmental damage not only on wildlife, but also on human health (cancers, obesity, fatigue, depression...). The solutions to this problem are however simple, efficient and, de facto, inexpensive because they involve a substantial energy saving.

[Old phenotype and new genotypes. Pituitary adenomas]

Gigantism and acromegaly, usually caused by a pituitary adenoma linked inappropriate secretion of growth hormone (GH), are generally considered as very rare diseases, even if, according to some authors, their cumulative prevalence is about 1/5000. Starting from the historical case of a giant from Liège we shall describe the different types of GH pituitary adenomas and their pathophysiology. We shall particularly discuss rare forms of inherited GH secreting pituitary adenomas like the FIPA (familial inherited isolated pituitary adenomas) and the X-LAG (X linked acrogigantism), both described for the first time in Liège, in 2000 and 2014, respectively.

Abstract 4731: Targeting super-enhancer induced gene expression with the novel BRD4 inhibitor OTX015 in preclinical models of MYCN-amplified neuroblastoma

Bromodomain-containing protein 4 (BRD4) functions as an epigenetic reader and binds to promoter super-enhancer regions driving oncogenes such as MYC. Neuroblastomas (NB) harboring MYCN amplifications are highly lethal tumors often resistant to standard chemotherapy. OTX015 is a novel BRD2/3/4 inhibitor currently in clinical Phase Ib studies in hematologic malignancies and solid tumors. We have previously reported that OTX015 displayed in vitro and in vivo antitumor effects, together with MYCN transcription attenuation in NB models (Henssen et al; AACR 2014). Here, we investigated OTX015 targeting of super-enhancer regulated genes in MYCN-amplified NB in vitro and in vivo models. Protein-DNA interactions were analyzed using ChipSeq in IMR 5 cells. We identified super-enhancers associated with a variety of genes of known importance in NB, including MYCN, as well as some previously undescribed genes. OTX015 inhibited cell proliferation in Chp-212, Chp-134, Gimen, IMR-32, NB69, SK-N-AS, SK-N-BE, and SK-N-BE2 NB cell lines after 72 h exposure. OTX015 reduced tumor burden in IMR 5 xenograft mice and in a genetically engineered model of MYCN-amplified NB LSL MYCN;Dbh-iCre, when administered by oral gavage at a dose of 25 mg/kg daily for 3 weeks. Antitumoral effects of OTX015 were coupled with decreased binding of BRD4 to chromatin and subsequent global transcriptional changes. Moreover, OTX015 exposure led to significant transcriptional downregulation of genes associated with super-enhancers, supporting the notion that BRD4 preferentially acts at these chromatin sites. Interestingly, BRD inhibition not only attenuated MYCN transcription but most significantly affected MYCN-regulated transcriptional programs. Ectopic expression of MYCN was not able to abrogate the antitumoral effects of BRD4 inhibition, indicating direct involvement of MYCN in super-enhancer regulated gene expression and possibly explaining the increased susceptibility of MYCN-amplified NB to OTX015 inhibition. We describe here for the first time that BRD inhibition by OTX015 selectively and preferentially targets global super-enhancer induced transcription in MYCN-driven NB. These new insights will serve as a rationale for a clinical trial in pediatric MYCN-amplified NB patients with OTX015.

Citation Format: Anton Henssen, Kristina Althoff, Richard Koche, Andrea Odersky, Anneleen Beckers, Frank Speleman, Simon Schäfers, Katleen De Preter, Alexandra Florin, Lukas Heukamp, Annika Spruessel, Kathy Astrahanseff, Natalie Sadowski, Alexander Schramm, Angelika Eggert, Lucile Astorgues-Xerri, Eugenia Riveiro, Esteban Cvitkovic, Johannes H. Schulte. Targeting super-enhancer induced gene expression with the novel BRD4 inhibitor OTX015 in preclinical models of MYCN-amplified neuroblastoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4731. doi:10.1158/1538-7445.AM2015-4731

[Alpha interferon induced hyperthyroidism: a case report and review of the literature]

Treatment with alpha interferon in hepatitis C triggers a thyroid autoimmunity in a variable percentage of cases (2-8%). This complication raises some questions about its screening, the possibility to continue anti-viral therapy and thyroid treatment. Alpha interferon has an immunomodulatory effect on the thyroid, but also an inhibitory effect on thyroid hormone synthesis. This explains the occurrence of cases of thyroid dysfunction, which often remain undetected because of their latency. Factors predicting thyroid dysfunction with interferon use are: female sex, history of thyroid disease and previous autoimmunity. Several clinical aspects are encountered including hypothyroidism (the most frequent depending on the series) and hyperthyroidism related to Graves' disease. For their detection, a cooperation between general practionners, gastroenterologists and endocrinologists is mandatory thyroid function tests are requested before, during and after treatment,with alpha interferon. Therapeutic aspects of thyroid disorders range from simple monitoring to symptomatic treatment, such as thyroxine prescription in the presence of hypothyroidism. Antithyroid drugs radioactive iodine or thyroid surgery are used in cases of severe or persistent Graves' disease induced by alpha interferon.

MYCN-driven regulatory mechanisms controlling LIN28B in neuroblastoma

LIN28B has been identified as an oncogene in various tumor entities, including neuroblastoma, a childhood cancer that originates from neural crest-derived cells, and is characterized by amplification of the MYCN oncogene. Recently, elevated LIN28B expression levels were shown to contribute to neuroblastoma tumorigenesis via let-7 dependent de-repression of MYCN. However, additional insight in the regulation of LIN28B in neuroblastoma is lacking. Therefore, we have performed a comprehensive analysis of the regulation of LIN28B in neuroblastoma, with a specific focus on the contribution of miRNAs. We show that MYCN regulates LIN28B expression in neuroblastoma tumors via two distinct parallel mechanisms. First, through an unbiased LIN28B-3'UTR reporter screen, we found that miR-26a-5p and miR-26b-5p regulate LIN28B expression. Next, we demonstrated that MYCN indirectly affects the expression of miR-26a-5p, and hence regulates LIN28B, therefore establishing an MYCN-miR-26a-5p-LIN28B regulatory axis. Second, we provide evidence that MYCN regulates LIN28B expression via interaction with the LIN28B promoter, establishing a direct MYCN-LIN28B regulatory axis. We believe that these findings mark LIN28B as an important effector of the MYCN oncogenic phenotype and underline the importance of MYCN-regulated miRNAs in establishing the MYCN-driven oncogenic process.

Upregulation of MAPK Negative Feedback Regulators and RET in Mutant ALK Neuroblastoma: Implications for Targeted Treatment

PURPOSE

Activating ALK mutations are present in almost 10% of primary neuroblastomas and mark patients for treatment with small-molecule ALK inhibitors in clinical trials. However, recent studies have shown that multiple mechanisms drive resistance to these molecular therapies. We anticipated that detailed mapping of the oncogenic ALK-driven signaling in neuroblastoma can aid to identify potential fragile nodes as additional targets for combination therapies.

EXPERIMENTAL DESIGN

To achieve this goal, transcriptome profiling was performed in neuroblastoma cell lines with the ALK(F1174L) or ALK(R1275Q) hotspot mutations, ALK amplification, or wild-type ALK following pharmacologic inhibition of ALK using four different compounds. Next, we performed cross-species genomic analyses to identify commonly transcriptionally perturbed genes in MYCN/ALK(F1174L) double transgenic versus MYCN transgenic mouse tumors as compared with the mutant ALK-driven transcriptome in human neuroblastomas.

RESULTS

A 77-gene ALK signature was established and successfully validated in primary neuroblastoma samples, in a neuroblastoma cell line with ALK(F1174L) and ALK(R1275Q) regulable overexpression constructs and in other ALKomas. In addition to the previously established PI3K/AKT/mTOR, MAPK/ERK, and MYC/MYCN signaling branches, we identified that mutant ALK drives a strong upregulation of MAPK negative feedback regulators and upregulates RET and RET-driven sympathetic neuronal markers of the cholinergic lineage.

CONCLUSIONS

We provide important novel insights into the transcriptional consequences and the complexity of mutant ALK signaling in this aggressive pediatric tumor. The negative feedback loop of MAPK pathway inhibitors may affect novel ALK inhibition therapies, whereas mutant ALK induced RET signaling can offer novel opportunities for testing ALK-RET oriented molecular combination therapies.

[Amiodarone and the thyroid]

Amiodarone is an antiarrhythmic agent among the I most powerful and the most frequently used for the control of recurrent ventricular tachycardia and the secondary prevention of recurrent atrial fibrillation. Its use is not without risk. Although highly effective, it may induce various, sometimes severe, side effects, particularly at the thyroid level.In patients receiving amiodarone, one can encounter biological changes without clinical repercussion. Some may present a true thyroid disease, either hyper- or hypothyroidism. In this literature review, we will see how to prevent, diagnose, and treat these complications,if required.