Analysis of circulating microRNAs in adrenocortical tumors

Serum microRNAs as new biomarkers for detecting subclinical hemolysis in the nonacute phase of G6PD deficiency

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is one of the most common enzymopathies worldwide. Patients with G6PD deficiency are usually asymptomatic throughout their life but can develop acute hemolysis after exposure to free radicals or certain medications. Several studies have shown that serum miRNAs can be used as prognostic biomarkers in various types of hemolytic anemias. However, the impact of G6PD deficiency on circulating miRNA profiles is largely unknown. The present study aimed to assess the use of serum miRNAs as biomarkers for detecting hemolysis in the nonacute phase of G6PD deficiency. Patients with severe or moderate G6PD Viangchan (871G > A) deficiency and normal G6PD patients were enrolled in the present study. The biochemical hemolysis indices were normal in the three groups, while the levels of serum miR-451a, miR-16, and miR-155 were significantly increased in patients with severe G6PD deficiency. In addition, 3D analysis of a set of three miRNAs (miR-451a, miR-16, and miR-155) was able to differentiate G6PD-deficient individuals from healthy individuals, suggesting that these three miRNAs may serve as potential biomarkers for patients in the nonhemolytic phase of G6PD deficiency. In conclusion, miRNAs can be utilized as additional biomarkers to detect hemolysis in the nonacute phase of G6PD deficiency.

Circulating non-coding RNA biomarkers of endocrine tumours

Circulating non-coding RNA (ncRNA) molecules are being investigated as biomarkers of malignancy, prognosis and follow-up in several neoplasms, including endocrine tumours of the pituitary, parathyroid, pancreas and adrenal glands. Most of these tumours are classified as neuroendocrine neoplasms (comprised of neuroendocrine tumours and neuroendocrine carcinomas) and include tumours of variable aggressivity. We consider them together here in this Review owing to similarities in their clinical presentation, pathomechanism and genetic background. No preoperative biomarkers of malignancy are available for several forms of these endocrine tumours. Moreover, biomarkers are also needed for the follow-up of tumour progression (especially in hormonally inactive tumours), prognosis and treatment efficacy monitoring. Circulating blood-borne ncRNAs show promising utility as biomarkers. These ncRNAs, including microRNAs, long non-coding RNAs and circular RNAs, are involved in several aspects of gene expression regulation, and their stability and tissue-specific expression could make them ideal biomarkers. However, no circulating ncRNA biomarkers have yet been introduced into routine clinical practice, which is mostly owing to methodological and standardization problems. In this Review, following a brief synopsis of these endocrine tumours and the biology of ncRNAs, the major research findings, pathomechanisms and methodological questions are discussed along with an outlook for future studies.

Advances in translational research of the rare cancer type adrenocortical carcinoma

Adrenocortical carcinoma is a rare malignancy with an annual worldwide incidence of 1-2 cases per 1 million and a 5-year survival rate of <60%. Although adrenocortical carcinoma is rare, such rare cancers account for approximately one third of patients diagnosed with cancer annually. In the past decade, there have been considerable advances in understanding the molecular basis of adrenocortical carcinoma. The genetic events associated with adrenocortical carcinoma in adults are distinct from those of paediatric cases, which are often associated with germline or somatic TP53 mutations and have a better prognosis. In adult primary adrenocortical carcinoma, the main somatic genetic alterations occur in genes that encode proteins involved in the WNT-β-catenin pathway, cell cycle and p53 apoptosis pathway, chromatin remodelling and telomere maintenance pathway, cAMP-protein kinase A (PKA) pathway or DNA transcription and RNA translation pathways. Recently, integrated molecular studies of adrenocortical carcinomas, which have characterized somatic mutations and the methylome as well as gene and microRNA expression profiles, have led to a molecular classification of these tumours that can predict prognosis and have helped to identify new therapeutic targets. In this Review, we summarize these recent translational research advances in adrenocortical carcinoma, which it is hoped could lead to improved patient diagnosis, treatment and outcome.

miRNAs orchestration of adrenocortical carcinoma - Particular emphasis on diagnosis, progression and drug resistance

Adrenocortical carcinoma (ACC) is an uncommon aggressive endocrine malignancy that is nonetheless associated with significant mortality and morbidity rates because of endocrine and oncological consequences. Recent genome-wide investigations of ACC have advanced our understanding of the disease, but substantial obstacles remain to overcome regarding diagnosis and prognosis. MicroRNAs (miRNAs, miRs) play a crucial role in the development and metastasis of a wide range of carcinomas by regulating the expression of their target genes through various mechanisms causing translational repression or messenger RNA (mRNA) degradation. Along with miRNAs in the adrenocortical cancerous tissue, circulating miRNAs are considered barely invasive diagnostic or prognostic biomarkers of ACC. miRNAs may serve as treatment targets that expand the rather-limited therapeutic repertoire in the field of ACC. Patients with advanced ACC still have a poor prognosis when using the available treatments, despite a substantial improvement in understanding of the illness over the previous few decades. Accordingly, in this review, we provide a crucial overview of the recent studies in ACC-associated miRNAs regarding their diagnostic, prognostic, and potential therapeutic relevance.

Molecular tools for diagnosing diseases of the adrenal cortex

PURPOSE OF REVIEW

The adrenal glands produce some of the most essential for life hormones, including cortisol and other steroids, and catecholamines. The former is produced from the adrenal cortex, whereas the latter is from the medulla. The two parts are anatomically and functionally distinct and it would be impossible in the context of one short article to cover all molecular updates on both the cortex and the medulla. Thus, in this review, we focus on the molecular tools available for diagnosing adrenocortical diseases, such as adrenal insufficiency, Cushing and Conn syndromes, and their potential for advancing medical care and clinical outcome.

RECENT FINDINGS

The advent of next generation sequencing opened doors for finding genetic diseases and signaling pathways involved in adrenocortical diseases. In addition, the combination of molecular data and clinicopathologic assessment might be the best approach for an early and precise diagnosis contributing to therapeutic decisions and improvement of patient outcomes.

SUMMARY

Diagnosing adrenocortical diseases can be challenging; however, the progress of molecular tools for adrenocortical disease diagnosis has greatly contributed to early detection and to meliorate patient outcomes.

Cerebrospinal fluid exosomal microRNAs as biomarkers for diagnosing or monitoring the progression of non-small cell lung cancer with leptomeningeal metastases

Non-small-cell lung cancer (NSCLC) has a terrible consequence called leptomeningeal metastases (LM). It is crucial to look for novel biomarkers because none of the known biomarkers could effectively reflect the oncogenesis, progression and therapeutic responses of LM. Exosomal miRNAs from plasma have a critical function in lung cancer, according to growing data. However, unique biomarkers of cerebrospinal fluid (CSF) are more representative for patients with LM, which have not been reported. Here, we explore the possibility of using CSF-derived exosomal microRNAs as potential biomarkers for NSCLC-LM. Nine NSCLC-LM patients who received regular intrathecal chemotherapy with permetexed were divided into a partial response (PR) group and a progressive disease (PD) group. CSF samples were taken from all patients before and after intrathecal treatment and five non-cancerous controls. Using the size exclusion chromatography (SEC) method, the exosome microRNAs were isolated and profiled. Between LM patients and controls, 56 differentially expressed genes (DEGs) were found, of which three highly elevated diagnostic biomarkers (hsa-miR-183-5p, hsa-miR-96-5p and hsa-miR-182-5p) were ruled out. The two most significant DEGs between the untreated PR group and the PD group were determined to be upregulated hsa-miR-509-3p and downregulated hsa-miR-449a, and they may serve as potential indicators of intrathecal anti-pemetrexed treatment. Hsa-miR-1-3p increased gradually with the intrathecal chemotherapy in the PR group, which might offer a new approach to screen optimal patients and estimate the efficacy. This study revealed specific CSF exosomal miRNAs profile and dynamic changes of patients with NSCLC-LM for the first time and identified several potential exosomal miRNA biomarkers in diagnosis, drug resistance and prognosis.

MicroRNA-375 in extracellular vesicles - novel marker for esophageal cancer diagnosis

BACKGROUND

MicroRNAs have been confirmed to function as diagnostic biomarkers for esophageal cancer (EC). This study aimed to investigate the diagnostic potential of miR-375 in the plasma or extracellular vesicles (EVs) of esophageal cancers (ECs).

METHODS

miRNAs with diagnostic potential were identified through public database searches and validated through clinical sample testing. The diagnostic value of miR-375 in plasma and EVs was evaluated via receiver operating characteristic analysis and area under the curve. In addition, expression and survival analyses of the top ten target genes of miR-375 were conducted using the cancer genome atlas database.

RESULTS

MiR-375 was identified as a potential biomarker for ECs by searching the gene expression omnibus database. Results of clinical sample measurements showed that miR-375 in plasma or EVs was significantly different between ECs and controls ( P < .01), but did not differ by gender or age. receiver operating characteristic analysis demonstrated that miR-375 in EVs could function as a diagnostic marker for ECs, with a higher area under the curve (0.852) than that in plasma. The expression and survival analysis of the top ten target genes for miR-375 showed that only EIF4G3 was significantly associated with survival ( P < .05).

CONCLUSION

This research shows that miR-375, particularly in EVs, could serve as a biomarker for the diagnosis of ECs.

Update on Biology and Genomics of Adrenocortical Carcinomas: Rationale for Emerging Therapies

The adrenal glands are paired endocrine organs that produce steroid hormones and catecholamines required for life. Adrenocortical carcinoma (ACC) is a rare and often fatal cancer of the peripheral domain of the gland, the adrenal cortex. Recent research in adrenal development, homeostasis, and disease have refined our understanding of the cellular and molecular programs controlling cortical growth and renewal, uncovering crucial clues into how physiologic programs are hijacked in early and late stages of malignant neoplasia. Alongside these studies, genome-wide approaches to examine adrenocortical tumors have transformed our understanding of ACC biology, and revealed that ACC is composed of distinct molecular subtypes associated with favorable, intermediate, and dismal clinical outcomes. The homogeneous transcriptional and epigenetic programs prevailing in each ACC subtype suggest likely susceptibility to any of a plethora of existing and novel targeted agents, with the caveat that therapeutic response may ultimately be limited by cancer cell plasticity. Despite enormous biomedical research advances in the last decade, the only potentially curative therapy for ACC to date is primary surgical resection, and up to 75% of patients will develop metastatic disease refractory to standard-of-care adjuvant mitotane and cytotoxic chemotherapy. A comprehensive, integrated, and current bench-to-bedside understanding of our field's investigations into adrenocortical physiology and neoplasia is crucial to developing novel clinical tools and approaches to equip the one-in-a-million patient fighting this devastating disease.

MicroRNAs and Long Non-Coding RNAs in Adrenocortical Carcinoma

Non-coding RNAs (ncRNAs) are a type of genetic material that do not encode proteins but regulate the gene expression at an epigenetic level, such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). The role played by ncRNAs in many physiological and pathological processes has gained attention during the last few decades, as they might be useful in the diagnosis, treatment and management of several human disorders, including endocrine and oncological diseases. Adrenocortical carcinoma (ACC) is a rare and aggressive endocrine cancer, still characterized by high mortality and morbidity due to both endocrine and oncological complications. Despite the rarity of this disease, recently, the role of ncRNA has been quite extensively evaluated in ACC. In order to better explore the role of the ncRNA in human ACC, this review summarizes the current knowledge on ncRNA dysregulation in ACC and its potential role in the diagnosis, treatment, and management of this tumor.

Characterization of Adrenal miRNA-Based Dysregulations in Cushing's Syndrome

MiRNAs are important epigenetic players with tissue- and disease-specific effects. In this study, our aim was to investigate the putative differential expression of miRNAs in adrenal tissues from different forms of Cushing’s syndrome (CS). For this, miRNA-based next-generation sequencing was performed in adrenal tissues taken from patients with ACTH-independent cortisol-producing adrenocortical adenomas (CPA), from patients with ACTH-dependent pituitary Cushing’s disease (CD) after bilateral adrenalectomy, and from control subjects. A confirmatory QPCR was also performed in adrenals from patients with other CS subtypes, such as primary bilateral macronodular hyperplasia and ectopic CS. Sequencing revealed significant differences in the miRNA profiles of CD and CPA. QPCR revealed the upregulated expression of miR-1247-5p in CPA and PBMAH (log2 fold change > 2.5, p < 0.05). MiR-379-5p was found to be upregulated in PBMAH and CD (log2 fold change > 1.8, p < 0.05). Analyses of miR-1247-5p and miR-379-5p expression in the adrenals of mice which had been exposed to short-term ACTH stimulation showed no influence on the adrenal miRNA expression profiles. For miRNA-specific target prediction, RNA-seq data from the adrenals of CPA, PBMAH, and control samples were analyzed with different bioinformatic platforms. The analyses revealed that both miR-1247-5p and miR-379-5p target specific genes in the WNT signaling pathway. In conclusion, this study identified distinct adrenal miRNAs as being associated with CS subtypes.

Tissue miRNA Combinations for the Differential Diagnosis of Adrenocortical Carcinoma and Adenoma Established by Artificial Intelligence

Simple Summary

The histological differential diagnosis of adrenocortical adenoma and carcinoma is difficult and requires great expertise. MiRNAs were shown to be useful for the differential diagnosis of benign and malignant tumors of several organs, and several findings have suggested their utility in adrenocortical tumors as well. Here, we have selected tissue miRNAs based on the literature search, and used machine learning to identify novel clinically applicable miRNA combinations. Combinations with high sensitivity and specificity (both over 90%) have been identified that could be promising for clinical use. Besides being a useful adjunct to histological examination, these miRNA combinations could enable preoperative adrenal biopsy in patients with adrenal tumors suspicious for malignancy.

Abstract

The histological analysis of adrenal tumors is difficult and requires great expertise. Tissue microRNA (miRNA) expression is distinct between benign and malignant tumors of several organs and can be useful for diagnostic purposes. MiRNAs are stable and their expression can be reliably reproduced from archived formalin-fixed, paraffin-embedded (FFPE) tissue blocks. Our purpose was to assess the potential applicability of combinations of literature-based miRNAs as markers of adrenocortical malignancy. Archived FFPE tissue samples from 10 adrenocortical carcinoma (ACC), 10 adrenocortical adenoma (ACA) and 10 normal adrenal cortex samples were analyzed in a discovery cohort, while 21 ACC and 22 ACA patients were studied in a blind manner in the validation cohort. The expression of miRNA was determined by RT-qPCR. Machine learning and neural network-based methods were used to find the best performing miRNA combination models. To evaluate diagnostic applicability, ROC-analysis was performed. We have identified three miRNA combinations (hsa-miR-195 + hsa-miR-210 + hsa-miR-503; hsa-miR-210 + hsa-miR-375 + hsa-miR-503 and hsa-miR-210 + hsa-miR-483-5p + hsa-miR-503) as unexpectedly good predictors to determine adrenocortical malignancy with sensitivity and specificity both of over 90%. These miRNA panels can supplement the histological examination of removed tumors and could even be performed from small volume adrenal biopsy samples preoperatively.

The Diagnostic, Prognostic and Therapeutic Role of miRNAs in Adrenocortical Carcinoma: A Systematic Review

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with a dismal prognosis and a high rate of recurrence and mortality. Therapeutic options are limited. In some cases, the distinction of ACCs from benign adrenal neoplasms with the existing widely available pathological and histopathological tools is difficult. Thus, new biomarkers have been tested. We conducted a review of the recent literature on the advances of the diagnostic, prognostic and therapeutic role of miRNAs on ACC patients. More than 10 miRNAs validated by multiple studies were found to present a diagnostic and prognostic role for ACC patients, from which miR-483-5p and miR-195 were the most frequently met biomarkers. In particular, upregulation of miR-483-5p and downregulation of miR-195 were the most commonly validated molecular alterations. Unfortunately, data on the therapeutic role of miRNA are still scarce and limited mainly at the experimental level. Thus, the role of miRNA regulation in ACC remains an area of active research.

How to Differentiate Benign from Malignant Adrenocortical Tumors?

Simple Summary

Adrenocortical carcinoma is a rare cancer with a poor prognosis. Adrenal tumors are, however, commonly identified in clinical practice. Discrimination between benign and malignant adrenal tumors is of great importance to determine the appropriate treatment and follow-up strategy. This review summarizes the current diagnostic strategies and challenges to distinguish benign from malignant adrenal lesions. We will focus both on radiological and biochemical assessments, enabling diagnosis of the adrenal lesion preoperatively, and on histopathological and a wide variety of molecular assessments that can be done after surgical removal of the adrenal lesion. Furthermore, new non-invasive strategies such as liquid biopsies, in which blood samples are used to study circulating tumor cells, tumor DNA and microRNA, will be addressed in this review.

Abstract

Adrenocortical carcinoma (ACC) is a rare cancer with a poor prognosis. Adrenal incidentalomas are, however, commonly identified in clinical practice. Discrimination between benign and malignant adrenal tumors is of great importance considering the large differences in clinical behavior requiring different strategies. Diagnosis of ACC starts with a thorough physical examination, biochemical evaluation, and imaging. Computed tomography is the first-level imaging modality in adrenal tumors, with tumor size and Hounsfield units being important features for determining malignancy. New developments include the use of urine metabolomics, also enabling discrimination of ACC from adenomas preoperatively. Postoperatively, the Weiss score is used for diagnosis of ACC, consisting of nine histopathological criteria. Due to known limitations as interobserver variability and lack of accuracy in borderline cases, much effort has been put into new tools to diagnose ACC. Novel developments vary from immunohistochemical markers and pathological scores, to markers at the level of DNA, methylome, chromosome, or microRNA. Molecular studies have provided insights into the most promising and most frequent alterations in ACC. The use of liquid biopsies for diagnosis of ACC is studied, although in a small number of patients, requiring further investigation. In this review, current diagnostic modalities and challenges in ACC will be addressed.

Immunotherapy in Adrenocortical Carcinoma: Predictors of Response, Efficacy, Safety, and Mechanisms of Resistance

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with limited treatment options in the advanced stages. Immunotherapy offers hope for altering the orthodox management of cancer, and its role in advanced ACC has been investigated in different studies. With the aim clarifying the role of immunotherapy in ACC we performed a comprehensive review about this topic focusing on the predictors of response, efficacy, safety, and the mechanisms of resistance. Five clinical trials with four immune checkpoint inhibitors (pembrolizumab, avelumab, nivolumab, and ipilimumab) have investigated the role of immunotherapy in advanced ACC. Despite, the different primary endpoints used in these studies, the reported rates of overall response rate and progression free survival were generally poor. Three main potential markers of response to immunotherapy in ACC have been described: Expression of PD-1 and PD-L1, microsatellite instability and tumor mutational burden. However, none of them has been validated in prospective studies. Several mechanisms of ACC immunoevasion may be responsible of immunotherapy failure, and a greater knowledge of these mechanisms might lead to the development of new strategies to overcome the immunotherapy resistance. In conclusion, although currently the role of immunotherapy is limited, the identification of immunological markers of response and the implementation of strategies to avoid immunotherapy resistance could improve the efficacy of this therapy.

Circulating microRNA Expression in Cushing's Syndrome

Context

Cushing's syndrome (CS) is a rare disease of endogenous hypercortisolism associated with high morbidity and mortality. Diagnosis and classification of CS is still challenging.

Objective

Circulating microRNAs (miRNAs) are minimally invasive diagnostic markers. Our aim was to characterize the circulating miRNA profiles of CS patients and to identify distinct profiles between the two major CS subtypes.

Methods

We included three groups of patients from the German Cushing's registry: ACTH-independent CS (Cortisol-Producing-Adenoma; CPA), ACTH-dependent pituitary CS (Cushing's Disease; CD), and patients in whom CS had been ruled out (controls). Profiling of miRNAs was performed by next-generation-sequencing (NGS) in serum samples of 15 CS patients (each before and after curative surgery) and 10 controls. Significant miRNAs were first validated by qPCR in the discovery cohort and then in an independent validation cohort of 20 CS patients and 11 controls.

Results

NGS identified 411 circulating miRNAs. Differential expression of 14 miRNAs were found in the pre- and postoperative groups. qPCR in the discovery cohort validated 5 of the significant miRNAs from the preoperative group analyses. Only, miR-182-5p was found to be significantly upregulated in the CD group of the validation cohort. Comparing all CS samples as a group with the controls did not reveal any significant differences in expression.

Outcome

In conclusion, our study identified miR-182-5p as a possible biomarker for CD, which has to be validated in a prospective cohort. Furthermore, our results suggest that presence or absence of ACTH might be at least as relevant for miRNA expression as hypercortisolism itself.

Future Directions in Diagnosis, Prognosis and Disease Monitoring of Adrenocortical Carcinoma: Novel Non-Invasive Biomarkers

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with frequent metastatic spread and poor prognosis. The disease can occur at any age with unexpected biological behavior. Recent genome-wide studies of ACC have contributed to our understanding of the disease, but diagnosis of ACC remains a challenge, even for multidisciplinary expert teams. Patients with ACC are frequently diagnosed in advanced stages and have limited therapeutic options. Therefore, for earlier diagnosis and better clinical management of adrenocortical carcinoma, specific, sensitive, and minimal invasive markers are urgently needed. Over several decades, great efforts have been made in discovering novel and reliable diagnostic and prognostic biomarkers including microRNAs, steroid profilings, circulating tumor cells, circulating tumor DNAs and radiomics. In this review, we will summarize these novel noninvasive biomarkers and analyze their values for diagnosis, predicting prognosis, and disease monitoring. Current problems and possible future application of these non-invasive biomarkers will also be discussed.

Alternative Splicing Events and Splicing Factors Are Prognostic in Adrenocortical Carcinoma

Alternative splicing is involved in the pathogenesis of human diseases, including cancer. Here, we investigated the potential application of alternative splicing events (ASEs) and splicing factors (SFs) in the prognosis of adrenocortical carcinoma (ACC). Transcriptome data from 79 ACC cases were downloaded from The Cancer Genome Atlas database, and percent spliced-in values of seven splicing types were downloaded from The Cancer Genome Atlas SpliceSeq database. By the univariate Cox regression analysis, 1,839 survival-related ASEs were identified. Prognostic indices based on seven types of survival-related ASEs were calculated by multivariate Cox regression analysis. Survival curves and receiver operating characteristic curves were used to assess the diagnostic value of the prognostic model. Independent prognosis analysis identified several ASEs (e.g., THNSL2| 54469| ME) that could be used as biomarkers to predict the prognosis of patients with ACC accurately. By analyzing the co-expression correlation between SFs and ASEs, 188 highly correlated interactions were established. From the protein interaction network, we finally screened six hub SFs, including YBX1, SART1, PRCC, SNRPG, SNRPE, and SF3B4, whose expression levels were significantly related to the overall survival and prognosis of ACC. Our findings provide a reliable model for predicting the prognosis of ACC patients based on aberrant alternative splicing patterns.

Key MicroRNA's and Their Targetome in Adrenocortical Cancer

Adrenocortical Carcinoma (ACC) is a rare but aggressive malignancy with poor prognosis and limited response to available systemic therapies. Although complete surgical resection gives the best chance for long-term survival, ACC has a two-year recurrence rate of 50%, which poses a therapeutic challenge. High throughput analyses focused on characterizing the molecular signature of ACC have revealed specific micro-RNAs (miRNAs) that are associated with aggressive tumor phenotypes. MiRNAs are small non-coding RNA molecules that regulate gene expression by inhibiting mRNA translation or degrading mRNA transcripts and have been generally implicated in carcinogenesis. This review summarizes the current insights into dysregulated miRNAs in ACC tumorigenesis, their known functions, and specific targetomes. In addition, we explore the possibility of particular miRNAs to be exploited as clinical biomarkers in ACC and as potential therapeutics.

Molecular Basis of Primary Aldosteronism and Adrenal Cushing Syndrome

This review reports the main molecular alterations leading to development of benign cortisol- and/or aldosterone-secreting adrenal tumors. Causes of adrenal Cushing syndrome can be divided in 2 groups: multiple bilateral tumors or adenomas secreting cortisol. Bilateral causes are mainly primary pigmented nodular adrenocortical disease, most of the time due to PRKAR1A germline-inactivating mutations, and primary bilateral macronodular adrenal hyperplasia that can be caused in some rare syndromic cases by germline-inactivating mutations of MEN1, APC, and FH and of ARMC5 in isolated forms. PRKACA somatic-activating mutations are the main alterations in unilateral cortisol-producing adenomas. In primary hyperaldosteronism (PA), familial forms were identified in 1% to 5% of cases: familial hyperaldosteronism type I (FH-I) due to a chimeric CYP11B1/CYP11B2 hybrid gene, FH-II due to CLCN-2 germline mutations, FH-III due to KCNJ5 germline mutations, FH-IV due to CACNA1H germline mutations and PA, and seizures and neurological abnormalities syndrome due to CACNA1D germline mutations. Several somatic mutations have been found in aldosterone-producing adenomas in KCNJ5, ATP1A1, ATP2B3, CACNA1D, and CTNNB1 genes.

In addition to these genetic alterations, genome-wide approaches identified several new alterations in transcriptome, methylome, and miRnome studies, highlighting new pathways involved in steroid dysregulation.

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.

Identification of non-invasive biomarkers for predicting the radiosensitivity of nasopharyngeal carcinoma from serum microRNAs

Serum microRNAs (miRNAs) have been reported as novel biomarkers for various diseases. But circulating biomarkers for predicting the radiosensitivity of nasopharyngeal carcinoma (NPC) have not been used in clinical practice. To screen out of differently expressed serum miRNAs from NPC patients with different radiosensitivity may be helpful for its individual therapy. NPC patients with different radiosensitivity were enrolled according to the inclusion and exclusion criteria. RNA was isolated from serum of these NPC patients before treatment. We investigated the differential miRNA expression profiles using microarray test (GSE139164), and the candidate miRNAs were validated by reverse transcription-quantitative real time polymerase chain reaction (RT-qPCR) experiments. Receiver operating characteristic (ROC) analysis has been applied to estimate the diagnostic value. In this study, 37 serum-specific miRNAs were screened out from 12 NPC patients with different radiosensitivity by microarray test. Furthermore, RT-qPCR analysis confirmed that hsa-miR-1281 and hsa-miR-6732-3p were significantly downregulated in the serum of radioresistant NPC patients (P < 0.05), which was consistent with the results of microarray test. ROC curves demonstrated that the AUC for hsa-miR-1281 was 0.750 (95% CI: 0.574-0.926, SE 87.5%, SP 57.1%). While the AUC for hsa-miR-6732-3p was 0.696 (95% CI: 0.507-0.886, SE 56.3%, SP 78.6%). These results suggested that hsa-miR-1281 and hsa-miR-6732-3p in serum might serve as potential biomarkers for predicting the radiosensitivity of NPC.

Early Postoperative Circulating miR-483-5p Is a Prognosis Marker for Adrenocortical Cancer

We have previously identified serum miR-483-5p as a preoperative diagnosis and prognosis biomarker for adrenocortical cancer (ACC). Here, we aimed to determine whether circulating miR-483-5p levels measured 3 months post-operatively distinguished patients with good prognosis (no recurrence for at least 3 years; NR3yrs) from patients with poor prognosis (recurrence or death within 3 years after surgery; R < 3yrs). We conducted a single-center retrospective analysis using sera from 48 patients with ACC that were initially non-metastatic and treated by surgery. Sera sampled within 3 months after surgery were available in 26 patients. MiR-483-5p absolute circulating levels were measured using quantitative PCR. Thirteen patients showed a recurrence before 3 years (=R < 3yrs). Thirteen patients showed no recurrence within 3 years, including 11 patients with a follow-up longer than 3 years (=NR3yrs). Serum miR-483-5p levels were higher in R < 3yrs than in NR3yrs: 1,541,990 ± 428,377 copies/mL vs. 388,457 ± 62,169 copies/mL (p = 0.002). Receiver operating characteristic analysis showed that a value of 752,898 copies/mL distinguished R < 3yrs from NR3yrs with 61.5% sensitivity (CI 31.6-86.1) and 100% specificity (CI 71.5-100) with an area under the curve of 0.853. Patients with a value below this threshold had a significantly longer recurrence-free and overall survival. In multivariate analysis, miR-483-5p provided the single best prognostic value for recurrence-free survival (RFS) (hazard ratio (HR) for recurrence 5.98, p < 0.011) but not for overall survival. Our study suggests that serum miR-483-5p is a potent early post-operative biomarker for ACC prognosis that might be a better predictor of RFS than currently used markers.

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.

Genomics of benign adrenocortical tumors

Benign adrenocortical adenomas and hyperplasia are relatively common and include a spectrum of distinct entities, which diagnosis depends on the macroscopic aspect and the secretion profile. Recent advances in genomics have proposed high-throughput molecular characterization of adrenal tumors, thereby improving our knowledge on the pathophysiology and tumorigenesis of these tumors. Genomic (exome and chromosome alteration profiles), epigenomic (micro-RNAs expression and methylation profiles) and transcriptomic (gene expression profiles) studies highlighted the major roles of intracellular calcium signaling in aldosterone-producing adenomas (APA), of protein kinase A (PKA)/cAMP pathway in cortisol-producing tumors, and of Wnt/beta-catenin pathway in non-secreting tumors. Exome sequencing revealed new major drivers in all tumor types, including KCNJ5, ATP1A1, ATP2B3, CACNA1D and CACNA1H mutations in APA, PRKACA mutations in cortisol-producing adenomas (CPA) and ARMC5 mutations in primary macronodular adrenocortical hyperplasia (PMAH). The clinical impact of these findings is just starting to evolve. The identification of genetic syndromes, such as germline ARMC5 mutations in PMAH, has allowed genetic counseling. Key molecular alterations could serve as a basis for the development of targeted medical treatments for benign adrenal tumors. The recent developments in genomics, including single-cell technologies, and in proteomics and metabolomics will probably offer new perspectives for characterizing benign adrenal tumorigenesis.

Adrenocortical carcinoma - towards genomics guided clinical care

Adrenocortical carcinoma (ACC) is an aggressive and rare neoplasm that originates in the cortex of the adrenal gland. The disease is associated with heterogeneous but mostly poor outcomes and lacks effective pharmaceutical treatment options. Multi-omics studies have defined the landscape of molecular alterations in ACC. Specific molecular signatures can be detected in body fluids, potentially enabling improved diagnostic applications for patients with adrenal tumours. Importantly, pan-molecular data sets further reveal a spectrum within ACC, with three major subgroups that have different disease outcomes. These new subgroups have value as prognostic biomarkers. Research has revealed that the p53-RB and the WNT-β-catenin pathways are common disease drivers in ACC. However, these pathways remain difficult to target by therapeutic interventions. Instead, a unique characteristic of ACC is steroidogenic differentiation, which has emerged as a potential treatment target, with several agents undergoing preclinical or clinical investigations. Finally, a large proportion of ACC tumours have genetic profiles that are associated with promising therapeutic responsiveness in other cancers. All these opportunities now await translation from the laboratory into the clinical setting, thereby offering a real potential of improved survival outcomes and increased quality of life for patients with this serious condition.

Circulating microRNAs in adrenal tumors

PURPOSE OF REVIEW

Circulating microRNAs represent promising minimally invasive markers of several diseases including tumors. As the preoperative diagnosis of different adrenal tumors is difficult, for example, diagnosis of adrenocortical or adrenomedullary malignancy, circulating microRNAs might be helpful in their clinical management.

RECENT FINDINGS

Observations regarding the applicability of circulating microRNAs isolated both from unfractionated plasma or serum and from extracellular vesicle preparations for the diagnosis of adrenocortical malignancy have been published. Data show that circulating microRNA might be exploited for monitoring adrenocortical cancer progression. Circulating microRNA profiles of adrenal myelolipoma have also been published that might be useful for differentiating adrenocortical cancer and adrenal myelolipoma in dubious cases.

SUMMARY

In this review, recent advances in the field of circulating microRNAs in adrenal tumors are discussed.

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.

Differential miRNA expression profile and proteome in plasma exosomes from patients with paroxysmal nocturnal hemoglobinuria

Paroxysmal Nocturnal Hemoglobinuria (PNH) is a clonal disease of blood cells caused by the lack of glycosyl phosphatidyl inositol anchored proteins bound to the cell membrane. In consequence, erythrocytes lead to intravascular hemolysis upon complement activation, which promotes high risk of thrombosis, intravascular hemolytic anemia, and bone marrow failure in patients. The mechanisms of thrombosis in PNH are still poorly understood. Treatment with eculizumab reduces intravascular hemolysis and thrombotic risk, but not in all cases. Exosomes are extracellular vesicles released by cells and whose secretion is closely related to the inflammatory status. They participate in cell communication by activating signaling pathways and transferring genetic material and proteins to host cells. In consequence, exosomes may serve as surrogate biomarkers for the prognosis and/or diagnosis of a disease. Isolation of exosomes was carried out from healthy controls and from three groups of PNH patients, i.e. i) with no eculizumab treatment; ii) under treatment with eculizumab that have not suffered thrombosis; and iii) under treatment with eculizumab but that have suffered thrombosis. The miRNAome and proteome was analyzed using plasma focus miRNAs PCR panel and LC-MS analysis respectively. We found differential expression of miRNAs miR-148b-3p, miR-423-3p, miR29b-3p, miR15b-5p, let-7e-5p, miR126-3p, miR-125b-5p and miR-376c-3p as well as hemoglobin, haptoglobin, protein S and C4-binding protein in healthy controls vs PNH patients. Our results warrant further research and provide new information on the content of exosomes that could play a role in the hypercoagulable state in this disease.

European Society of Endocrinology Clinical Practice Guidelines on the management of adrenocortical carcinoma in adults, in collaboration with the European Network for the Study of Adrenal Tumors

Adrenocortical carcinoma (ACC) is a rare and in most cases steroid hormone-producing tumor with variable prognosis. The purpose of these guidelines is to provide clinicians with best possible evidence-based recommendations for clinical management of patients with ACC based on the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. We predefined four main clinical questions, which we judged as particularly important for the management of ACC patients and performed systematic literature searches: (A) What is needed to diagnose an ACC by histopathology? (B) Which are the best prognostic markers in ACC? (C) Is adjuvant therapy able to prevent recurrent disease or reduce mortality after radical resection? (D) What is the best treatment option for macroscopically incompletely resected, recurrent or metastatic disease? Other relevant questions were discussed within the group. Selected Recommendations: (i) We recommend that all patients with suspected and proven ACC are discussed in a multidisciplinary expert team meeting. (ii) We recommend that every patient with (suspected) ACC should undergo careful clinical assessment, detailed endocrine work-up to identify autonomous hormone excess and adrenal-focused imaging. (iii) We recommend that adrenal surgery for (suspected) ACC should be performed only by surgeons experienced in adrenal and oncological surgery aiming at a complete en bloc resection (including resection of oligo-metastatic disease). (iv) We suggest that all suspected ACC should be reviewed by an expert adrenal pathologist using the Weiss score and providing Ki67 index. (v) We suggest adjuvant mitotane treatment in patients after radical surgery that have a perceived high risk of recurrence (ENSAT stage III, or R1 resection, or Ki67 >10%). (vi) For advanced ACC not amenable to complete surgical resection, local therapeutic measures (e.g. radiation therapy, radiofrequency ablation, chemoembolization) are of particular value. However, we suggest against the routine use of adrenal surgery in case of widespread metastatic disease. In these patients, we recommend either mitotane monotherapy or mitotane, etoposide, doxorubicin and cisplatin depending on prognostic parameters. In selected patients with a good response, surgery may be subsequently considered. (vii) In patients with recurrent disease and a disease-free interval of at least 12 months, in whom a complete resection/ablation seems feasible, we recommend surgery or alternatively other local therapies. Furthermore, we offer detailed recommendations about the management of mitotane treatment and other supportive therapies. Finally, we suggest directions for future research.

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.

Identification of micro-RNA expression profile related to recurrence in women with ESMO low-risk endometrial cancer

Background

Actual European pathological classification of early-stage endometrial cancer (EC) may show insufficient accuracy to precisely stratify recurrence risk, leading to potential over or under treatment. Micro-RNAs are post-transcriptional regulators involved in carcinogenic mechanisms, with some micro-RNA patterns of expression associated with EC characteristics and prognosis. We previously demonstrated that downregulation of micro-RNA-184 was associated with lymph node involvement in low-risk EC (LREC). The aim of this study was to evaluate whether micro-RNA signature in tumor tissues from LREC women can be correlated with the occurrence of recurrences.

Methods

MicroRNA expression was assessed by chip analysis and qRT-PCR in 7 formalin-fixed paraffin-embedded (FFPE) LREC primary tumors from women whose follow up showed recurrences (R+) and in 14 FFPE LREC primary tumors from women whose follow up did not show any recurrence (R−), matched for grade and age. Various statistical analyses, including enrichment analysis and a minimum p-value approach, were performed.

Results

The expression levels of micro-RNAs-184, -497-5p, and -196b-3p were significantly lower in R+ compared to R− women. Women with a micro-RNA-184 fold change < 0.083 were more likely to show recurrence (n = 6; 66%) compared to those with a micro-RNA-184 fold change > 0.083 (n = 1; 8%), p = 0.016. Women with a micro-RNA-196 fold change < 0.56 were more likely to show recurrence (n = 5; 100%) compared to those with a micro-RNA-196 fold change > 0.56 (n = 2; 13%), p = 0.001.

Conclusions

These findings confirm the great interest of micro-RNA-184 as a prognostic tool to improve the management of LREC women.

MANAGEMENT OF ENDOCRINE DISEASE: Adrenocortical carcinoma: differentiating the good from the poor prognosis tumors

Adrenocortical carcinoma (ACC) is a rare malignancy with a poor prognosis, the five-years overall survival being below 40%. However, there is great variability of outcomes and we have now a better view of the heterogeneity of tumor aggressiveness. The extent of the disease at the time of diagnosis, best assayed by the European Network for the Study of Adrenal Tumors (ENSAT) Staging Score, is a major determinant of survival. The tumor grade, including the mitotic count and the Ki67 proliferation index, also appears as a strong prognostic factor. The assessment of tumor grade, even by expert pathologists, still suffers from inter-observer reproducibility. The emergence of genomics in the last decade has revolutionized the knowledge of molecular biology and genetics of cancers. In ACC, genomic approaches - including pan-genomic studies of gene expression (transcriptome), recurrent mutations (exome or whole-genome sequencing), chromosome alterations, DNA methylation (methylome), miRNA expression (miRnome) - converge in a new classification of ACC, characterized by distinct molecular profiles and very different outcomes. Targeted measurements of a few discriminant molecular alterations have been developed in the perspective of clinical routine, and thus, may help defining therapeutic strategy. By individualizing patients' prognosis and tumor biology, these recent progresses appear as an important step forward towards precision medicine.

Adrenocortical carcinoma: the dawn of a new era of genomic and molecular biology analysis

Over the last decade, the development of novel and high penetrance genomic approaches to analyze biological samples has provided very new insights in the comprehension of the molecular biology and genetics of tumors. The use of these techniques, consisting of exome sequencing, transcriptome, miRNome, chromosome alteration, genome, and epigenome analysis, has also been successfully applied to adrenocortical carcinoma (ACC). In fact, the analysis of large cohorts of patients allowed the stratification of ACC with different patterns of molecular alterations, associated with different outcomes, thus providing a novel molecular classification of the malignancy to be associated with the classical pathological analysis. Improving our knowledge about ACC molecular features will result not only in a better diagnostic and prognostic accuracy, but also in the identification of more specific therapeutic targets for the development of more effective pharmacological anti-cancer approaches. In particular, the specific molecular alteration profiles identified in ACC may represent targetable events by the use of already developed or newly designed drugs enabling a better and more efficacious management of the ACC patient in the context of new frontiers of personalized precision medicine.

MiR-483-5p and miR-139-5p promote aggressiveness by targeting N-myc downstream-regulated gene family members in adrenocortical cancer

Adrenocortical carcinoma (ACC) is a tumor with poor prognosis in which overexpression of a panel of microRNAs has been associated with malignancy but a very limited number of investigations on their role in ACC pathogenesis have been conducted. We examined the involvement of miR-483-5p and miR-139-5p in adrenocortical cancer aggressiveness. Using bioinformatics predictions and mRNA/miRNA expression profiles, we performed an integrated analysis to identify inversely correlated miRNA-mRNA pairs in ACC. We identified N-myc downstream-regulated gene family members 2 and 4 (NDRG2 and NDRG4) as targets of miR-483-5p and miR-139-5p, respectively. NDRG2 and NDRG4 expressions were inversely correlated respectively with miR-483-5p and miR-139-5p levels in aggressive ACC samples from two independent cohorts of 20 and 44 ACC. Moreover, upregulation of miR-139-5p and downregulation of NDRG4 demonstrated a striking prognostic value. A direct interaction between miR-483-5p or miR-139-5p and their targets was demonstrated in reporter assays. Downregulation of miR-483-5p or miR-139-5p in the ACC cell lines NCI-H295R and SW13 increased NDRG2 or NDRG4 mRNA and protein expression, compromised adrenocortical cancer cell invasiveness and anchorage-independent growth. MiR-483-5p or miR-139-5p overexpression and NDRG2 or NDRG4 inhibition produce similar changes, which are rescued by NDRG2 or NDRG4 ectopic expression. We established that key factors mediating epithelial-to-mesenchymal transition are downstream effectors of miR-483-5p/NDRG2 and miR-139-5p/NDRG4 pathways. Collectively, our data show for the first time that miR-483-5p/NDRG2 and miR-139-5p/NDRG4 axes promote ACC aggressiveness, with potential implications for prognosis and therapeutic interventions in adrenocortical malignancies.

Circulating microRNAs found dysregulated in ex-exposed asbestos workers and pleural mesothelioma patients as potential new biomarkers

Malignant pleural mesothelioma (MPM), a fatal cancer, is an occupational disease mostly affecting workers ex-exposed to asbestos fibers. The asbestos, a cancerogenic mineral of different chemical composition, was widely employed in western Countries in industrial manufactures of different types. MPM may arise after a long latency period, up to five decades. MPM is resistant to conventional chemo- and radio-therapies. Altogether, these data indicate that the identification of new and specific markers are of a paramount importance for an early diagnosis and treatment of MPM. In recent years, microRNAs expression was found dysregulated in patients, both in cancer cells and sera, affected by tumors of different histotypes, including MPM. Cell and circulanting microRNAs, found to be dysregulated in this neoplasia, were proposed as new biomarkers. It has been reported that circulating microRNAs are stable in biological fluids and could be employed as potential MPM biomarkers. In this investigation, circulating microRNAs (miR) from serum samples of MPM patients and workers ex-exposed to asbestos fibers (WEA) and healthy subjects (HS) were comparatively analyzed by microarray and RT-qPCR technologies. Our results allowed (i) to select MiR-3665, an endogenous stable microRNA, as the internal control to quantify in our analyses circulating miRNAs; to detect (ii) miR-197-3p, miR-1281 and miR 32-3p up-regulated in MPM compared to HS; (iii) miR-197-3p and miR-32-3p up-regulated in MPM compared to WEA; (iv) miR-1281 up-regulated in both MPM and WEA compared to HS. In conclusion, three circulating up-regulated microRNAs, i.e. miR-197-3p, miR-1281 and miR-32-3p are proposed as potential new MPM biomarkers.

The next step: mechanisms driving adrenocortical carcinoma metastasis

Endocrine tumors have the peculiarity to become clinically evident not only due to symptoms related to space occupation by the growing lesion, similarly to most other tumors, but also, and most often, because of their specific hormonal secretion, which significantly contributes to their pathological burden. Malignant endocrine tumors, in addition, have the ability to produce distant metastases. Here, we critically review the current knowledge about mechanisms and biomarkers characterizing the metastatic process in adrenocortical carcinoma (ACC), a rare endocrine malignancy with a high risk of relapse and metastatization even when the primary tumor is diagnosed and surgically removed at an early stage. We highlight perspectives of future research in the domain and possible new therapeutic avenues based on targeting factors having an important role in the metastatic process of ACC.

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.

Role of miR-483 in digestive tract cancers: from basic research to clinical value

Digestive tract cancers (DTCs) is the most common malignant tumors in the world. Despite surgery and medical technology have witnessed the increasing development and sharp advancement in the past decade, DTCs remain a critical concern with high morbidity and mortality. Since a class of small noncoding RNAs termed miRNAs were identified several years ago, increasing studies have attempted to illustrate the relationship between the specific miRNAs dysregulated expression levels and the diseases phenotypic changes. For example, microRNA-483 (miR-483) aberrant expression plays a pivotal part in tumor biology in a variety of human cancer, including DTCs. In this review, we focus on the present key findings from recent profiling studies, discuss the use of miR-483 as a novel biomarker for DTCs. At the same time, we emphasize the significant diversities and technical difficulties must be overcome before clinically relevant signatures arose. It is believed that this might provide researchers an insight into the molecular targeting cancer treatment.

Plasma microRNA Profile Differentiates Crohn's Colitis From Ulcerative Colitis

BACKGROUND

Inflammatory bowel disease (IBD) is commonly divided into 2 entities: Crohn's disease (CD) and ulcerative colitis (UC). Differentiating between these entities when dealing with IBD confined to the colon is important, especially when planning surgical treatment. Due to ambiguous histological or endoscopic findings, accurate diagnosis is not possible in up to 15% of cases. The aim of this study was to determine whether plasma microRNAs (miRNAs) can help differentiate Crohn's colitis (CC) from ulcerative colitis.

METHODS

Patients with isolated CC and with UC were enrolled in our study from January 2010 to May 2016. Peripheral blood was collected, and total RNA was isolated from plasma. Screening was performed for 380 common miRNAs. miRNAs that were differentially expressed between these 2 groups were chosen, and their differential expression was confirmed using single miRNA assays in a larger sample size. A predictive model was generated using these data. Significantly differentially expressed miRNAs were then validated utilizing the predictive model to assess blinded data from the single assays.

RESULTS

Screening was performed on 8 patients from each group. Seven differentially expressed miRNAs were chosen for single assay confirmation. Two miRNAs (miR-598, miR-642) were consistently different between the patient groups (P = 0.013, P = 0.005). Using blinded data, these 2 miRNAs were validated using the predictive model, achieving an overall accuracy of 75% (95% confidence interval, 40.7-92.9).

CONCLUSIONS

We identified 2 plasma miRNAs that differentiated CC from UC. Our data indicate the promise and feasibility of a plasma miRNA-based assay to distinguish between these 2 conditions.

Advances in understanding the molecular underpinnings of adrenocortical tumors

PURPOSE OF REVIEW

Adrenocortical tumors are divided into benign adenomas and malignant carcinomas. The former is relatively common and carries a favorable prognosis, whereas the latter is rare and frequently presents at an advanced stage, with poor outcomes. Advances in next-generation sequencing, genome analysis, and bioinformatics have allowed for high-throughput molecular characterization of adrenal tumorigenesis.

RECENT FINDINGS

Although recent genomic, epigenomic, and transcriptomic studies in large tumor cohorts have confirmed the central roles of aberrant Wnt/ß-catenin signaling, constitutive protein kinase A pathway activation, cell cycle dysregulation, and ion channelopathies in adrenal tumorigenesis, these studies also revealed novel signature events underlying malignant differentiation of adrenocortical carcinomas.

SUMMARY

Recent advances in understanding of the molecular mechanisms underlying adrenocortical tumorigenesis provide new molecular diagnostic and prognostic tools and opportunities for novel therapeutic approaches. These findings are particularly important in adrenocortical carcinoma, for which current treatment options are limited.

The role of microRNAs in the pathophysiology of adrenal tumors

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression in a sequence-specific manner. Due to its association with an assortment of diseases, miRNAs have been extensively studied in the last decade. In this review, the current understanding of the role of miRNAs in the pathophysiology of adrenal tumors is discussed. The recent contributions of high-throughput miRNA profiling studies have identified miRNAs that have functional and molecular roles in adrenal tumorigenesis. With respect to the biological heterogeneity of adrenal tumors and the limitations of the current treatments, an improved understanding of miRNAs may hold potential diagnostic and therapeutic value to facilitate better clinical management.

Role of microRNAs in endocrine cancer metastasis

The deregulation of transcription and processing of microRNAs (miRNAs), as well as their function, has been involved in the pathogenesis of several human diseases, including cancer. Despite advances in therapeutic approaches, cancer still represents one of the major health problems worldwide. Cancer metastasis is an aggravating factor in tumor progression, related to increased treatment complexity and a worse prognosis. After more than one decade of extensive studies of miRNAs, the fundamental role of these molecules in cancer progression and metastasis is beginning to be elucidated. Recent evidences have demonstrated a significant role of miRNAs on the metastatic cascade, acting either as pro-metastatic or anti-metastatic. They are involved in distinct steps of metastasis including epithelial-to-mesenchymal transition, migration/invasion, anoikis survival, and distant organ colonization. Studies on the roles of miRNAs in cancer have focused mainly on two fronts: the establishment of a miRNA signature for different tumors, which may aid in early diagnosis using these miRNAs as markers, and functional studies of specific miRNAs, determining their targets, function and regulation. Functional miRNA studies on endocrine cancers are still scarce and represent an important area of research, since some tumors, although not frequent, present a high mortality rate. Among the endocrine tumors, thyroid cancer is the most common and best studied. Several miRNAs show lowered expression in endocrine cancers (i.e. miR-200s, miR-126, miR-7, miR-29a, miR-30a, miR-137, miR-206, miR-101, miR-613, miR-539, miR-205, miR-9, miR-195), while others are commonly overexpressed (i.e. miR-21, miR-183, miR-31, miR-let7b, miR-584, miR-146b, miR-221, miR-222, miR-25, miR-595). Additionally, some miRNAs were found in serum exosomes (miR-151, miR-145, miR-31), potentially serving as diagnostic tools. In this review, we summarize studies concerning the discovery and functions of miRNAs and their regulatory roles in endocrine cancer metastasis, which may contribute for the finding of novel therapeutic targets. The review focus on miRNAs with at least some identified targets, with established functions and, if possible, upstream regulation.

Is there a role for epithelial-mesenchymal transition in adrenocortical tumors?

PURPOSE

Epithelial-mesenchymal transition (EMT) is a biological dynamic process by which epithelial cells lose their epithelial phenotype and acquire mesenchymal invasive and migratory characteristics. This has been postulated as an essential step during cancer progression and metastasis. Although this is well described in other tumors, the role of EMT in adrenocortical tumors (ACT) has yet to be addressed.

METHODS

The aim of this study was to evaluate the expression of EMT markers e-cadherin, vimentin, and fibronectin, along with EMT-transcription factors (EMT-TFs), TWIST1, SIP1, and SNAIL in 24 adrenocortical carcinoma (ACC), 19 adrenocortical adenomas (ACA), 27 childhood-onset adrenocortical tumors (CAT), and 12 normal adrenal glands. The association of EMT and EMT-TFs with clinical outcomes and pathology features were also evaluated.

RESULTS

Cytoplasmic vimentin expression was increased among CAT samples when compared to ACC, ACA, and normal adrenal samples (p < 0.001). There was no difference in e-cadherin and fibronectin expression observed between groups. Nuclear and cytoplasmic expression of TWIST1 and SIP1 was stronger in CAT and ACC vs. ACA and normal tissue samples (all, p < 0.05). ACT, regardless of classification, exhibited increased SNAIL expression when compared to normal tissue (p < 0.05). A significant correlation was observed between vimentin and TWIST1 (r _s = 0.44, p < 0.001); SIP1 (r _s = 0.51, p < 0.001); and SNAIL (r _s = 0.23, p < 0.05). TWIST1 and SIP1 expressions demonstrated a significant correlation (r _s = 0.56, p < 0.001). High SIP1 expression was associated with a lower survival rate among ACC cases (p < 0.05).

CONCLUSIONS

Vimentin, TWIST1, and SIP1 expressions are increased in aggressive ACT. Therefore, EMT may play a relevant role in adrenal tumorigenesis.

MiR-483-5p promotes IGF-II transcription and is associated with poor prognosis of hepatocellular carcinoma

The human insulin-like growth factor-II (IGF-II) gene transcribes four mRNAs (P1 mRNA-P4 mRNA), and P3 mRNA overexpression contributes to hepatocarcinogenesis. IGF-II-derived miR-483-5p is implicated in the development of cancers. Here, we investigated the involvement of miR-483-5p in P3 mRNA overexpression regulation and its role in hepatocellular carcinoma. Our results showed that miR-483-5p up-regulated P3 mRNA transcription by targeting the 5′-untranslated region (5′UTR) of P3 mRNA in hepatocellular carcinoma. The mechanism was involved in recruiting of an argonaute 1(Ago1)-argonaute 2 (Ago2) complex to the P3 mRNA 5′UTR and the P3 promoter of IGF-II gene by miR-483-5p, accompanied by increased enrichment of RNA polymerase II and activating histone marks histone 3 lysine 4 trimethylation (H3K4me3), histone 3 lysine 27 acetylation (H3K27ac), and histone 4 lysine 5/8/12/16 acetylation (H4Kac) at the P3 promoter. High miR-483-5p expression was an independent predictor for shorter survival of HCC patients. The findings suggest that miR-483-5p promotes P3 mRNA transcription by recruiting the Ago1-Ago2 complex to the P3 mRNA 5′UTR and is associated with poor prognosis of HCC. Our results display a potential new model for miRNAs to up-regulate gene expression.

Small Non-coding RNA Abundance in Adrenocortical Carcinoma: A Footprint of a Rare Cancer

BACKGROUND: Adrenocortical carcinoma (ACC) is a relatively rare, but aggressive type of cancer, which affects both children and adults. OBJECTIVE: Small non-coding RNAs (sncRNAs) play important roles and may serve as biomarkers for disease diagnosis, prognosis and treatment. METHODS: In our study, we sought to identify sncRNAs associated with malignant adrenal tumors. We obtained publicly available, small RNA sequencing data derived from 45 ACC and 30 benign tumors arising from the cortex of the adrenal gland, adrenocortical adenomas (ACA), and compared their sncRNA expression profiles. RESULTS: First, we remapped small RNA-seq to miRBase version 21 to check expression of miRNAs and found 147 miRNAs were aberrantly expressed (p<0.05) in ACC samples compared to ACA samples. Pathway analysis of differentially expressed miRNAs revealed p53 signaling pathways to be profoundly affected in ACC samples. Further examination for other types of small RNAs revealed 16 piRNAs, 48 lncRNAs and 19 sn/snoRNAs identified in ACC samples. Conclusions: Our data analysis suggests that publically available resources can be mined for biomarker development and improvements in-patient care; however, further research must be performed to correlate tumor grade with gene expression.

Assessment of VAV2 Expression Refines Prognostic Prediction in Adrenocortical Carcinoma

CONTEXT

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with overall poor prognosis. The Ki67 labeling index (LI) has a major prognostic role in localized ACC after complete resection, but its estimates may suffer from considerable intra- and interobserver variability. VAV2 overexpression induced by increased Steroidogenic Factor-1 dosage is an essential factor driving ACC tumor cell invasion.

OBJECTIVE

To assess the prognostic role of VAV2 expression in ACC by investigation of a large cohort of patients.

DESIGN, SETTING, AND PARTICIPANTS

A total of 171 ACC cases (157 primary tumors, six local recurrences, eight metastases) from seven European Network for the Study of Adrenal Tumors centers were studied.

OUTCOME MEASUREMENTS

H-scores were generated to quantify VAV2 expression. VAV2 expression was divided into two categories: low (H-score, <2) and high (H-score, ≥2). The Ki67 LI retrieved from patients' pathology records was also categorized into low (<20%) and high (≥20%). Clinical and immunohistochemical markers were correlated with progression-free survival (PFS) and overall survival (OS).

RESULTS

VAV2 expression and Ki67 LI were significantly correlated with each other and with PFS and OS. Heterogeneity of VAV2 expression inside the same tumor was very low. Combined assessment of VAV2 expression and Ki67 LI improved patient stratification to low-risk and high-risk groups.

CONCLUSION

Combined assessment of Ki67 LI and VAV2 expression improves prognostic prediction in ACC.

Translational applications of microRNAs in cancer, and therapeutic implications

The search for targeted novel therapies for cancer is ongoing. MicroRNAs (miRNAs) display a number of characteristics making them an attractive and realisable option. In this review, we explore these applications, ranging from diagnostics, prognostics, disease surveillance, to being a primary therapy or a tool to sensitise patients to treatment modalities such as chemotherapy and radiotherapy. We take a particular perspective towards miRNAs and their impact on rare cancers. Advancement in the delivery of miRNAs, from viral vectors and liposomal delivery to nanoparticle based, has led to a number of pre-clinical and clinical applications for microRNA cancer therapeutics. This is promising, especially in the setting of rare cancers.

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.

New insights in the clinical and translational relevance of miR483-5p in adrenocortical cancer

Adrenocortical cancer (ACC) is a rare aggressive malignancy. Recent ACC integrated genomics analysis contributed to redefine the risk groups on molecular basis, including tumor microRNAs (miRs), detectable also in the bloodstream. We developed a quantitative real-time (RT) assay for the measurement of miR483 and miR483-5p absolute levels in plasma samples. miR483/miR483-5p levels were evaluated in plasma samples of 27 patients with ACC before surgery and at follow-up.

Statistically significant differences in miR483-5p and miR483 levels were found between stage 1/2 and stage 3/4 ACCs in pre-surgery and post-surgery samples. ROC curve analysis of miR483–5p levels gave a prediction of the clinical stage (accuracy 0.917±0.084), with the best cut-off value of 0.221 ng/ml, prognosticating overall and recurrence-free survival. In a multivariate Cox analysis (HR 16.2, 95%CI[1.39-188.6, P<0.026]), miR483-5p was the only variable that significantly predicted recurrence, but not overall survival. In addition, miR483 and miR483-5p levels correlated with the number of circulating tumor cells (CTCs) detected in the same blood samples, independently of the timing of sampling. In conclusion, we demonstrated that miR483-5p absolute plasma levels in ACC patients are powerful molecular markers that may help in the follow-up of patients after surgery and chemotherapy, and contribute to more accurately classify and predict tumor progression.