The Influence of the Gut Microbiome in Paediatric Cancer Origin and Treatment.

Knowledge of the complexity of the gut microbiota is expanding, and its importance in physiological processes and disease development is widely studied. The aim of this review is to present the most relevant and recent research on the associations between gut microbiota and oncologic disease. Recently, a number of associations between the gut microbiome and neoplasms-regarding tumorigenesis, prognosis and therapeutic efficacy-have been reported. The effects of the gut microbiome on these processes are via the direct and indirect immunomodulating effects of bacteria. Studies have been done mainly in adult populations, where its effect on immunomodulating therapies was unambiguous. In paediatric populations, however, due to the low number of cases and the complex therapeutic approaches, there have been only a few studies. Among them, children with acute lymphoblastic leukaemia were mainly involved. Significant alterations in the abundance of certain bacteria were associated with altered therapeutic responses. Regarding solid tumours, studies with low case numbers have been reported; no significant discoveries have been described so far. In the future, studies with larger cohorts are needed in order to better understand the associations between bacteria and neoplasms and to improve prognosis in the paediatric oncologic population.

Type 3 autoimmune polyglandular syndrome with multiple genetic alterations in a young male patient with type 1 diabetes mellitus.

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MicroRNAs and Adrenocortical Tumors: Where do we Stand on Primary Aldosteronism?

MicroRNAs, the endogenous mediators of RNA interference, interact with the renin-angiotensin-aldosterone system, regulate aldosterone secretion and aldosterone effects. Some novel data show that the expression of some microRNAs is altered in primary aldosteronism, and some of these appear to have pathogenic relevance, as well. Differences in the circulating microRNA expression profiles between the two major forms of primary aldosteronism, unilateral aldosterone-producing adenoma and bilateral adrenal hyperplasia have also been shown. Here, we present a brief synopsis of these findings focusing on the potential relevance of microRNA in primary aldosteronism.

Non-Coding RNAs in Adrenocortical Cancer: From Pathogenesis to Diagnosis.

Non-coding RNA molecules including microRNAs and long non-coding RNAs (lncRNA) have been implicated in the pathogenesis of several tumors and numerous data support their applicability in diagnosis as well. Despite recent advances, the pathogenesis of adrenocortical cancer still remains elusive and there are no reliable blood-borne markers of adrenocortical malignancy, either. Several findings show the potential applicability of microRNAs as biomarkers of malignancy and prognosis, and there are some data on lncRNA as well. In this review, we present a synopsis on the potential relevance of non-coding RNA molecules in adrenocortical pathogenesis and their applicability in diagnosis from tissue and blood.

Circulating miRNA Expression Profiling in Primary Aldosteronism.

Objective: Primary aldosteronism is a major cause of secondary hypertension. Its two principal forms are bilateral adrenal hyperplasia (BAH) and aldosterone-producing adenoma (APA) whose differentiation is clinically pivotal. There is a major clinical need for a reliable and easily accessible diagnostic biomarker for case identification and subtyping. Circulating microRNAs were shown to be useful as minimally invasive diagnostic markers. Our aim was to determine and compare the circulating microRNA expression profiles of adenoma and hyperplasia plasma samples, and to evaluate their applicability as minimally invasive markers. Methods: One hundred and twenty-three samples from primary aldosteronism patients were included. Next-generation sequencing was performed on 30 EDTA-anticoagulated plasma samples (discovery cohort). Significantly differently expressed miRNAs were validated by real-time reverse transcription-qPCR in an independent validation cohort (93 samples). Results: We have found relative overexpression of miR-30e-5p, miR-30d-5p, miR-223-3p, and miR-7-5p in hyperplasia compared to adenoma by next-generation sequencing. Validation by qRT-PCR confirmed significant overexpression of hsa-miR-30e-5p, hsa-miR-30d-5p, and hsa-miR-7-5p in hyperplasia samples. Regarding the microRNA expressional variations, adenoma is more heterogeneous at the miRNA level compared to hyperplasia. Conclusion: Three microRNAs were significantly overexpressed in hyperplasia samples compared to adenoma samples, but their sensitivity and specificity values are not good enough for introduction to clinical practice.

Overview of Genetically Determined Diseases/Multiple Endocrine Neoplasia Syndromes Predisposing to Endocrine Tumors.

In this chapter, we present an overview of multiple endocrine neoplasia syndromes including their most important clinical and molecular features. Multiple endocrine neoplasia type 1 and 2 syndromes (MEN1 and MEN2) are discussed in detail. Syndromes that are presented in other chapters are only briefly mentioned. We discuss the relevance of germline gene alterations in apparently sporadic endocrine tumors, e.g., medullary thyroid cancer, primary hyperparathyroidism, and neuroendocrine tumors. McCune-Albright syndrome that only exists in non-hereditary, sporadic forms is also discussed in detail, as tumors of several endocrine organs can develop in the same individual.

Comparison of plasma and urinary microRNA-483-5p for the diagnosis of adrenocortical malignancy.

INTRODUCTION: Minimally invasive circulating microRNAs might be used for the preoperative differentiation of adrenocortical carcinoma (ACC) and adrenocortical adenoma (ACA). So far, the best blood-borne microRNA biomarker of ACC is circulating hsa-miR-483-5p. The expression of urinary hsa-miR-483-5p as a non-invasive marker of malignancy and its correlation with plasma hsa-miR-483-5p, has not been investigated, yet. AIM: Our aim was to investigate the expression of urinary hsa-miR-483-5p and its correlation with its plasma counterpart. METHODS: Plasma and urinary samples from 23 ACC and 23 ACA patients were analysed using real-time RT-qPCR. To evaluate the diagnostic applicability of hsa-miR-483-5p, ROC-analysis was performed. RESULTS: Significant overexpression of hsa-miR-483-5p was observed in carcinoma patients' plasma samples compared to adenoma patients' (p < 0.0001, sensitivity: 87%, specificity: 78.3%). In urinary samples, however, no significant difference could be detected between ACC and ACA patients. CONCLUSIONS: Plasma hsa-miR-483-5p has been confirmed as significantly overexpressed in adrenocortical cancer patients and thus might be exploited as a minimally invasive preoperative marker of malignancy. The applicability of urinary hsa-miR-483-5p for the diagnosis of adrenocortical malignancy could not be confirmed.

MicroRNA Expression Profiling in Adrenal Myelolipoma.

Introduction: Adrenal myelolipoma (AML) is the second most common and invariably benign primary adrenal neoplasm. Due to the variable proportion of fat and hematopoietic elements and its often large size, it can cause differential diagnostic problems. Several reports confirmed the utility of miRNAs in the diagnosis of tumors, but miRNA expression in AML has not yet been investigated. Materials and Methods: Next-generation sequencing (NGS) was performed on 30 formalin-fixed, paraffin-embedded (FFPE) archived tissue samples [10 each of AML, adrenocortical adenoma (ACA), and adrenocortical carcinoma (ACC)]. Validation was performed by real-time quantitative reverse transcription polymerase chain reaction on a cohort containing 41 further FFPE samples (15 AML, 14 ACA, and 12 ACC samples). Circulating miRNA counterparts of significantly differentially expressed tissue miRNAs were studied in 33 plasma samples (11 each of ACA, ACC, and AML). Results: By NGS, 256 significantly differentially expressed miRNAs were discovered, and 8 of these were chosen for validation. Significant overexpression of hsa-miR-451a, hsa-miR-486-5p, hsa-miR-363-3p, and hsa-miR-150-5p was confirmed in AML relative to ACA and ACC. hsa-miR-184, hsa-miR-483-5p, and hsa-miR-183-5p were significantly overexpressed in ACC relative to ACA but not to AML. Circulating hsa-miR-451a and hsa-miR-363-3p were significantly overexpressed in AML, whereas circulating hsa-miR-483-5p and hsa-miR-483-3p were only significantly overexpressed in ACC vs ACA. Conclusions: We have found significantly differentially expressed miRNAs in AML and adrenocortical tumors. Circulating hsa-miR-451a might be a promising minimally invasive biomarker of AML. The lack of significantly different expression of hsa-miR-483-3p and hsa-miR-483-5p between AML and ACC might limit their applicability as diagnostic miRNA markers for ACC.

[Pathogenic and diagnostic roles of microRNAs in adrenocortical tumours]. / A mikro-RNS-ek patogenetikai és diagnosztikai szerepe mellékvesekéreg-carcinomában.

Adrenocortical tumours are quite prevalent. Most of these tumours are benign, hormonally inactive adrenocortical adenomas. Rare hormone-secreting adrenocortical adenomas are associated with severe clinical consequences, whereas the prognosis of the rare adrenocortical cancer is rather poor in its advanced stages. The pathogenesis of these tumours is only partly elucidated. MicroRNAs are small, non-coding RNA molecules that are pivotal in the regulation of several basic cell biological processes via the posttranscriptional regulation of gene expression. Their altered expression has been described in many tumours. Several tissue microRNAs, such as miR-483-5p, miR-503, miR-210, miR-335 and miR-195 were found to be differentially expressed among benign and malignant adrenocortical tumours, and these could also have pathogenic relevance. Due to their tissue specific and stable expression, microRNAs can be exploited in diagnostics as well. As the histological diagnosis of adrenocortical malignancy is difficult, microRNAs might be of help in the establishment of malignancy. Novel data show that microRNAs are secreted in various body fluids, projecting their applicability as biomarkers as part of liquid biopsy. In this review, we attempt to present a synopsis on the pathogenic relevance of microRNAs in adrenocortical tumours and their potential diagnostic applicability. Orv Hetil. 2018; 159(7): 245-251.

Analysis of circulating extracellular vesicle-associated microRNAs in cortisol-producing adrenocortical tumors.

PURPOSE: Circulating microRNAs (miRNA) have been described in patients with adrenocortical tumors, but the expression of miRNAs in non-functioning and cortisol-producing tumors has not been yet compared. Therefore, the objective of this study was to evaluate the expression of plasma extracellular vesicle (EV)-associated microRNAs in patients with non-functioning adrenocortical adenoma (NFA), cortisol-producing adrenocortical adenoma (CPA) and cortisol-producing adrenocortical carcinoma (CP-ACC). METHODS: Preoperative plasma EV samples of 13 NFAs, 13 CPAs and 9 CP-ACCs were subjected to extracellular vesicle isolation. miRNAs were investigated by targeted quantitative real-time PCR normalized to cel-miR-39 as reference. Five miRNAs have been selected for this analysis based on the previous studies including hsa-miR-22-3p, hsa-miR-27a-3p, hsa-miR-210-3p, hsa-miR-320b and hsa-miR-375. RESULTS: We have observed significant overrepresentation of three miRNAs in both CPA and CP-ACC relative to NFA: hsa-miR-22-3p (p < 0.01 and p < 0.0001, respectively), hsa-miR-27a-3p (p < 0.05 in both comparisons) and hsa-miR-320b (p < 0.05 and p < 0.0001, respectively). Hsa-miR-320b has been significantly overrepresented in CP-ACC relative to CPA (p < 0.01). Hsa-miR-210-3p turned out to be significantly overrepresented only in CP-ACC compared to NFA (p < 0.05). Significant correlation was revealed between circulating miRNA concentrations and urinary free cortisol values for hsa-miR-22-3p, hsa-miR-27a-3p and hsa-miR-320b (p < 0.0001 for all) and cortisol after low-dose dexamethasone test for hsa-miR-22-3p and hsa-miR-320b (p < 0.05). Hsa-miR-27a-3p has been significantly stimulated by low-dose dexamethasone test (p < 0.05). CONCLUSIONS: EV-associated miRNAs are differentially expressed in different non-functioning and cortisol-producing adrenocortical tumors.

Adrenal myelolipoma: a comprehensive review.

INTRODUCTION: Adrenal myelolipoma is an invariably benign neoplasm of the adrenal gland that is the second most common primary adrenal incidentaloma following adrenocortical adenomas. It is composed of elements of adipose tissue and extramedullary hematopoiesis. Hypotheses on stem cells and hormonal factors have been formulated regarding its pathogenesis that is still obscure. Despite its benign behavior, adrenal myelolipoma is clinically relevant as it might cause significant difficulties in the differential diagnosis of adrenal tumors. METHODS: We have reviewed 420 cases reported between 1957 and 2017 on adrenal myelolipoma retrieved from PubMed and Scopus databases and also 20 of our case series to provide a comprehensive analysis of their pathology, epidemiological and clinical features. RESULTS AND CONCLUSIONS: The average age for its diagnosis was 51 years, and no gender difference was observed. The average size of tumors was 10.2 cm. Congenital adrenal hyperplasia was associated to 10% of all cases analyzed, while other adrenal hypersecretory disorders (cortisol, aldosterone) were found in 7.5% of cases. Computed tomography and magnetic resonance imaging can be reliably used for its differential diagnosis. If the diagnosis of an adrenal myelolipoma is unambiguous, and no associated symptoms or hormonal activity are established, surgical intervention is usually not necessary.

Evaluation and diagnostic potential of circulating extracellular vesicle-associated microRNAs in adrenocortical tumors.

There is no available blood marker for the preoperative diagnosis of adrenocortical malignancy. The objective of this study was to investigate the expression of extracellular vesicle-associated microRNAs and their diagnostic potential in plasma samples of patients suffering from adrenocortical tumors. Extracellular vesicles were isolated either by using Total Exosome Isolation Kit or by differential centrifugation/ultracentrifugation. Preoperative plasma extracellular vesicle samples of 6 adrenocortical adenomas (ACA) and 6 histologically verified adrenocortical cancer (ACC) were first screened by Taqman Human Microarray A-cards. Based on the results of screening, two miRNAs were selected and validated by targeted quantitative real-time PCR. The validation cohort included 18 ACAs and 16 ACCs. Beside RNA analysis, extracellular vesicle preparations were also assessed by transmission electron microscopy, flow cytometry and dynamic light scattering. Significant overexpression of hsa-miR-101 and hsa-miR-483-5p in ACC relative to ACA samples has been validated. Receiver operator characteristics of data revealed dCT hsa-miR-483-5p normalized to cel-miR-39 to have the highest diagnostic accuracy (area under curve 0.965), the sensitivity and the specifity were 87.5 and 94.44, respectively. Extracellular vesicle-associated hsa-miR-483-5p thus appears to be a promising minimally invasive biomarker in the preoperative diagnosis of ACC but needs further validation in larger cohorts of patients.

[Circulating microRNAs in the diagnostics of endocrine neoplasms]. / Keringo mikroRNS-ek az endokrin daganatok diagnosztikájában.

MicroRNAs (miRNA, miR) are short - 19-25 nucleotide long - single stranded (in their mature form), non-coding RNA molecules that regulate gene expression mostly at the posttranscriptional level. microRNAs are involved in the regulation of various physiological processes such as cell differentiation and proliferation, development, haematopoesis, cell death, while their aberrant expression is observed in numerous diseases, like autoimmune disorders, inflammations, vascular diseases or tumorigenesis. microRNAs are expressed in a tissue specific fashion. Beyond their appearance in tissues, they can be found in body fluids as well. microRNAs are present in blood, mother milk, semen, saliva, urine, etc. MicroRNAs in body fluids, especially the blood-borne circulating microRNAs can be exploited as minimally invasive biomarkers of tumor diagnosis. The number of endocrine tumor-associated circulating microRNA alterations is relatively low, mostly described for papillary thyroid cancer, adrenocortical cancer, ovarian and neuroendocrine tumors. As the histological diagnosis including the establishment of malignancy of some of these neoplasms is difficult, studies on circulating microRNAs might have great perspectives. Orv. Hetil., 2017, 158(13), 483-490.

Potential relevance of microRNAs in inter-species epigenetic communication, and implications for disease pathogenesis.

MicroRNAs are short non-protein coding RNA molecules involved in the epigenetic regulation of gene expression. Recently, extracellular microRNAs have been described in body fluids that might enable epigenetic communication between distant tissues. Being highly conserved molecules, exogenous xeno-microRNAs from different species could affect gene expression in the host even in a cross-kingdom fashion. Several data underline the relevance of microRNA-mediated communication between virus and host, and there are some experimental data showing that plant- or animal-derived dietary microRNAs might have gene expression modulating activity in humans. Milk-derived microRNAs might be involved in the "epigenetic priming" of the baby. Exogenous microRNAs might be hypothesized to be implicated in disease pathogenesis, e.g. in tumors. Major questions remain to be addressed including the amount of xeno-microRNAs needed for biological action or routes for microRNA delivery. In this brief review, experimental data and hypotheses on the potential pathogenic inter-species relevance of microRNA are presented.