MicroRNA expression patterns in adrenocortical carcinoma variants and clinical pathologic correlations

Updates on WHO 5th edition classification, molecular characteristics and tumor microenvironment of adrenocortical carcinomas

Discerning malignancy in adrenocortical tumors is clinically pivotal in the management of patients but has also been one of the most difficult areas in both clinical and pathology settings. The recently published WHO 5th edition "Endocrine and Neuroendocrine Tumours" recommends a diagnostic algorithm employing not only one but several proposed histopathological criteria-including the Weiss criteria and its revision and the Helsinki criteria-in addition to the Reticulin algorithm, the Ki-67 proliferative index, and others depending upon their histopathological features. On the other hand, the risk classification proposed by ENSAT (European Network of Study for Adrenal Tumors) in 2018 was primarily based on the Ki-67 proliferative index of carcinoma cells, especially focusing on whether or not postoperative or adjuvant chemotherapy could be administered. The recently reported results of the ADIUVO study, although preliminary, discuss the necessity of postoperative therapy with mitotane in patients with low-grade adrenocortical carcinomas (ACCs) after complete resection. In addition, recently reported comprehensive genetic analyses attempted to classify ACCs into four major molecular subtypes: (i) the Wnt/-catenin pathway, (ii) the p53/Rb1 pathway, (iii) the chromosomal maintenance/chromatin remodeling pathway, and (iv) the MMR (Mismatch repair) pathway. Among those, groups (i) and (ii) are more commonly detected in high-grade ACCs but it is also true that specific therapeutic targets based on the molecular characteristics of tumors have remained limited. In addition, possible effects of glucocorticoid excess in functional ACCs on the tumor microenvironment have also been examined, and the utility of immune checkpoint inhibitors is being explored at this juncture.

Evaluation of microRNAs as liquid biopsy markers in adrenocortical tumors

Introduction

Adrenal tumors (ATs) encompass a wide differential diagnosis, necessitating a multi-step process for accurate identification. Liquid biopsy emerges as a promising non-invasive technique for distinguishing between malignant and benign, as well as hyperfunctioning and non-functioning cases. Recent studies have highlighted the potential of microRNAs as circulating biomarkers; however, their clinical utility remains underexplored. This study aims to validate the diagnostic performance of selected circulating microRNAs, (miR-483-5p, miR-210, miR-335 and miR-22-3p), identified through microRNA profiling studies, as markers of malignancy or cortisol hypersecretion in a cohort of patients with ATs.

Methods

We collected serum samples from 75 patients with ATs, including 50 cases of adrenocortical adenomas (ACA) and 25 cases of adrenocortical carcinomas (ACC), along with 15 controls. In the ACC subgroup, 16 samples were obtained preoperatively or upon detection of recurrence (active ACC group), while the remaining from disease-free patients with long-term follow-up. Among the 56 patients with ATs evaluated preoperatively (50 with ACAs and 6 with ACC), 26 had non-functioning tumors, 22 exhibited mild autonomous cortisol secretion, and 8 had Cushing syndrome. Quantitative real-time polymerase chain reaction was employed to analyze microRNA expression.

Results

Circulating levels of miR-483-5p and miR-210 were significantly elevated in patients with active ACC compared to both ACAs (p<0.001 and p=0.004, respectively) and controls (p=0.02 and p = 0.03, respectively). Notably, miR-483-5p serum levels were higher in patients with active ACC compared to disease-free ACC patients (p = 0.01). MiR-483-5p demonstrated the best diagnostic accuracy for distinguishing active ACC cases from ACAs, achieving a sensitivity of 81.3% and a specificity of 88%, and from disease-free ACC patients, reaching sensitivity of 81.3% and specificity of 89%. MiR-22-3p serum levels successfully differentiated patients with Cushing syndrome from those with non-functioning ATs (area under the curve=AUC=0.800, 95% CI: 0.653-0.953, p=0.01) and controls (AUC= 0.800, 95% CI: 0.610-0.990, p=0.02). Additionally, circulating miR-22-3p levels exhibited a significant correlation with traditional diagnostic tests for hypercortisolism.

Conclusion

This study supports the potential of a liquid biopsy approach as an innovative method for diagnosing and monitoring patients with ATs, offering a complementary tool to existing diagnostic methods.

Analysis of miR-483-3p and miR-630 expression profile in pediatric adrenocortical tumors and the effect of their modulation on adrenal tumorigenesis in vitro

Pediatric adrenocortical tumors (ACT) are rare aggressive neoplasms with heterogeneous prognosis. MicroRNA (miRNA) signatures have been associated with cancer diagnosis, treatment response, and outcomes of several types of cancer. However, the role played by miRNAs in pediatric ACT has been poorly explored. In this study, we have evaluated the expression of miR-483-3p and miR-630 in 67 pediatric ACT and 19 non-neoplastic adrenal samples, the effects of the modulations of these miRNAs, and their relationship with the TGF-β pathway in the H295R and H295A cell lines. Deregulation of both miRNAs was related to survival and disease advanced stages and hence to patients' prognosis. Moreover, modified miR-483-3p and miR-630 in vitro expression decreased cell viability and colony formation capacity, changed how some genes of the TGF-β pathway, such as TGFBR1, TGFBR2, and SMAD7, are expressed, and altered Smad3, pSmad3, Smad 2/3, N-cadherin, and Vimentin protein expression. Besides that, when inhibition of the TGF-β pathway was combined with miR-630 overexpression or miR-483-3p silencing, cell viability and colony formation capacity decreased, and protein expression in the TGF-β pathway changed. Together, the data indicate that both miRNAs participate in the TGF-β pathway and are therefore potential markers for predicting the prognosis of patients with pediatric ACT.

Non-Coding RNAs of Mitochondrial Origin: Roles in Cell Division and Implications in Cancer

Non-coding RNAs (ncRNAs) are a heterogeneous group, in terms of structure and sequence length, consisting of RNA molecules that do not code for proteins. These ncRNAs have a central role in the regulation of gene expression and are virtually involved in every process analyzed, ensuring cellular homeostasis. Although, over the years, much research has focused on the characterization of non-coding transcripts of nuclear origin, improved bioinformatic tools and next-generation sequencing (NGS) platforms have allowed the identification of hundreds of ncRNAs transcribed from the mitochondrial genome (mt-ncRNA), including long non-coding RNA (lncRNA), circular RNA (circRNA), and microRNA (miR). Mt-ncRNAs have been described in diverse cellular processes such as mitochondrial proteome homeostasis and retrograde signaling; however, the function of the majority of mt-ncRNAs remains unknown. This review focuses on a subgroup of human mt-ncRNAs whose dysfunction is associated with both failures in cell cycle regulation, leading to defects in cell growth, cell proliferation, and apoptosis, and the development of tumor hallmarks, such as cell migration and metastasis formation, thus contributing to carcinogenesis and tumor development. Here we provide an overview of the mt-ncRNAs/cancer relationship that could help the future development of new biomedical applications in the field of oncology.

From diagnosis to resistance: a symphony of miRNAs in pheochromocytoma progression and treatment response

Pheochromocytoma (PCC) is a neuroendocrine tumor that produces and secretes catecholamine from either the adrenal medulla or extra-adrenal locations. MicroRNAs (miRNAs, miR) can be used as biomarkers to detect cancer or the return of a previously treated disease. Blood-borne miRNAs might be envisioned as noninvasive markers of malignancy or prognosis, and new studies demonstrate that microRNAs are released in body fluids as well as tissues. MiRNAs have the potential to be therapeutic targets, which would greatly increase the restricted therapy options for adrenal tumors. This article aims to consolidate and synthesize the most recent studies on miRNAs in PCC, discussing their potential clinical utility as diagnostic and prognostic biomarkers while also addressing their limitations.

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.

Review of Diagnostic Modalities for Adrenal Incidentaloma

Adrenal incidentalomas are common findings in clinical practice, with a prevalence of up to 4.2% in radiological studies. Due to the large number of focal lesions in the adrenal glands, it can be challenging to make a definitive diagnosis and determine the appropriate management. The purpose of this review is to present current diagnostic modalities used to preoperatively distinguish between adrenocortical adenoma (ACA) and adrenocortical cancer (ACC). Proper management and diagnosis are crucial in avoiding unnecessary adrenalectomies, which occur in over 40% of cases. A literature analysis was conducted to compare ACA and ACC using imaging studies, hormonal evaluation, pathological workup, and liquid biopsy. Before deciding on surgical treatment, the nature of the tumor can be accurately determined using noncontrast CT imaging combined with tumor size and metabolomics. This approach helps to narrow down the group of patients with adrenal tumors who require surgical treatment due to the suspected malignant nature of the lesion.

Histopathologic Features of Adrenal Cortical Carcinoma

Adrenal cortical carcinoma (ACC) is a rare and aggressive malignancy that poses challenging issues regarding the diagnostic workup. Indeed, no presurgical technique or clinical parameters can reliably distinguish between adrenal cortical adenomas, which are more frequent and have a favorable outcome, and ACC, and the final diagnosis largely relies on histopathologic analysis of the surgical specimen. However, even the pathologic assessment of malignancy in an adrenal cortical lesion is not straightforward and requires a combined evaluation of multiple histopathologic features. Starting from the Weiss score, which was developed in 1984, several histopathologic scoring systems have been designed to tackle the difficulties of ACC diagnosis. Dealing with specific histopathologic variants (eg, Liss-Weiss-Bisceglia scoring system for oncocytic ACC) or patient characteristics (eg, Wieneke index in the pediatric setting), these scores remarkably improved the diagnostic workup of ACC and its subtypes. Nevertheless, cases with misleading features or discordant correlations between pathologic findings and clinical behavior still occur. Owing to multicentric collaborative studies integrating morphologic features with ancillary immunohistochemical markers and molecular analysis, ACC has eventually emerged as a multifaceted, heterogenous malignancy, and, while innovative and promising approaches are currently being tested, the future clinical management of patients with ACC will mainly rely on personalized medicine and target-therapy protocols. At the dawn of the new Fifth World Health Organization classification of endocrine tumors, this review will tackle ACC from the pathologist's perspective, thus focusing on the main available diagnostic, prognostic, and predictive tissue-tethered features and biomarkers and providing relevant clinical and molecular correlates.

MicroRNA-149-3p expression correlates with outcomes of adrenocortical tumor patients and affects proliferation and cell cycle progression of H295A adrenocortical cancer cell line

Pediatric adrenocortical tumor (ACT) is a rare and aggressive neoplasm, with incidence in southern and southeastern Brazil 10-15 times higher than worldwide. Although microRNAs (miRNAs) have been reported to act as tumor suppressors or oncogenes in several cancers, the role of miR-149-3p in ACT remains unknown. In this study, we evaluated the expression of miR-149-3p in 67 pediatric ACT samples and 19 non-neoplastic adrenal tissues. The overexpression of miR-149-3p was induced in H295A cell line, and cell viability, proliferation, colony formation, and cell cycle were assessed by in miR-149-3p mimic or mimic control. In silico analysis were used to predict miR-149-3p putative target genes. CDKN1A expression at the mRNA and protein levels was evaluated by qRT-PCR and western blot, respectively. Higher miR-149-3p expression was associated with unfavorable ACT outcomes. Compared to the mimic control, miR-149-3p overexpression increased cell viability and colony formation, and affected cell cycle progression. Also, we identified CDKN1A as a potential miR-149-3p target gene, with decreased expression at both the gene and protein levels in miR-149-3p mimic cells. Collectively, these findings suggest that miR-149-3p promotes H295A cell viability by downregulating CDKN1A and provide evidence that miR-149-3p may be useful as a novel therapeutic target for pediatric ACT.

Exploratory Circular RNA Profiling in Adrenocortical Tumors

Differentiation of adrenocortical adenoma (ACA) and carcinoma (ACC) is often challenging even in the histological analysis. Circular RNAs (circRNAs) belonging to the group of non-coding RNAs have been implicated as relevant factors in tumorigenesis. Our aim was to explore circRNA expression profiles in adrenocortical tumors by next-generation sequencing followed by RT-qPCR validation. Archived FFPE (formalin-fixed, paraffin embedded) including 8 ACC, 8 ACA and 8 normal adrenal cortices (NAC) were used in the discovery cohort. For de novo and known circRNA expression profiling, a next-generation sequencing platform was used. CIRI2, CircExplorer2, AutoCirc bioinformatics tools were used for the discovery of circRNAs. The top five most differentially circRNAs were measured by RT-qPCR in an independent validation cohort (10 ACC, 8 ACA, 8 NAC). In silico predicted, interacting microRNAs potentially sponged by differentially expressed circRNAs were studied by individual RT-qPCR assays. We focused on overexpressed circRNAs here. Significantly differentially expressed circRNAs have been revealed between the cohorts by NGS. Only circPHC3 could be confirmed to be significantly overexpressed in ACC, ACA vs. NAC samples by RT-qPCR. We could not observe microRNA expression changes fully corresponding to our sponging hypothesis. To the best of our knowledge, our study is the first to investigate circRNAs in adrenocortical tumors. Further studies are warranted to explore their biological and diagnostic relevance.

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.

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

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.

A Critical Appraisal of Contemporary and Novel Biomarkers in Pheochromocytomas and Adrenocortical Tumors

Pheochromocytomas/Paragangliomas (PPGLs) and adrenocortical tumors are rare neoplasms with significant heterogeneity in their biologic and clinical behavior. Current diagnostic and predictive biomarkers include hormone secretion, as well as histopathological and genetic features. PPGL diagnosis is based on biochemical measurement of catecholamines/metanephrines, while histopathological scoring systems have been proposed to predict the risk of malignancy. Adrenocortical tumors are mostly benign, but some can be malignant. Currently, the stage of disease at diagnosis and tumor grade, appear to be the most powerful prognostic factors. However, recent genomic and proteomic studies have identified new genetic and circulating biomarkers, including genes, immunohistochemical markers and micro-RNAs that display high specificity and sensitivity as diagnostic or prognostic tools. In addition, new molecular classifications have been proposed that divide adrenal tumors in distinct subgroups with different clinical outcomes.

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.

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.

Screening and identification of key biomarkers in adrenocortical carcinoma based on bioinformatics analysis

Adrenocortical carcinoma (ACC) is a rare malignancy with a poor prognosis. The presently available understanding of the pathogenesis of ACC is incomplete and the treatment options for patients with ACC are limited. Gene marker identification is required for accurate and timely diagnosis of the disease. In order to identify novel candidate genes associated with the occurrence and progression of ACC, the microarray datasets, GSE12368 and GSE19750, were obtained from Gene Expression Omnibus. Differentially expressed genes (DEGs) were identified, and functional enrichment analysis was performed. A protein-protein interaction network (PPI) was constructed to identify significantly altered modules, and module analysis was performed using Search Tool for the Retrieval of Interacting Genes and Cytoscape. A total of 228 DEGs were screened, consisting of 29 up and 199 downregulated genes. The enriched functions and pathways of the DEGs primarily included 'cell division', 'regulation of transcription involved in G1/S transition of mitotic cell cycle', 'G1/S transition of mitotic cell cycle', 'p53 signaling pathway' and 'oocyte meiosis'. A total of 14 hub genes were identified, and biological process analysis revealed that these genes were significantly enriched in cell division and mitotic cell cycle. Furthermore, survival analysis revealed that AURKA, TYMS, GINS1, RACGAP1, RRM2, EZH2, ZWINT, CDK1, CCNB1, NCAPG and TPX2 may be involved in the tumorigenesis, progression or prognosis of ACC. In conclusion, the 14 hub genes identified in the present study may aid researchers in elucidating the molecular mechanisms associated with the tumorigenesis and progression of ACC, and may be powerful and promising candidate biomarkers for the diagnosis and treatment of ACC.

Competing Endogenous RNA Network Analysis Reveals Pivotal ceRNAs in Adrenocortical Carcinoma

Objective: To construct ceRNA network and identify pivotal competing endogenous RNAs (ceRNAs) in adrenocortical carcinoma (ACC) using ceRNA network analysis. Methods: The RNA sequencing expression data of 77 ACCs in TCGA were obtained from GEPIA. Cancer specific ceRNAs, cancer specific microRNAs (miRNAs), and cancer specific messenger RNAs (mRNAs) were identified. The interaction of cancer specific miRNAs with cancer specific ceRNAs and cancer specific mRNAs were predicted. CeRNA network was constructed and visualized by Cytoscape 3.7.0 software. The genes in ceRNA network regulated GO terms and regulated pathways were performed by function analysis. Survival analysis of pivotal ceRNAs was performed for the pivotal lncRNAs. Result: Twenty-eight cancer specific ceRNAs, 149 cancer specific miRNAs, and 104 mRNAs were identified. CeRNA network was constructed including 10 ceRNAs, 35 miRNAs, and 34 mRNAs. The genes in ceRNA network regulated GO terms and were classified into three groups: cellular component (CC), molecular function (MF), and biological process (BP). The genes in ceRNA network regulated the following pathways: leukocyte transendothelial migration, and proteoglycans in cancer. Survival analysis showed that CTB-63M22.1 and RP1-241P17.4 were significantly associated with ACC patient disease free survival and overall survival. Conclusion: This study has constructed ceRNA networks in ACC. The study provides a set of pivotal ceRNAs for future investigation into the molecular mechanisms.

Clinical and molecular prognostic factors in adrenocortical carcinoma

INTRODUCTION

Adrenocortical carcinoma (ACC) is a rare cancer, with an incidence less than 0.7-1.5 per 1 million people per year, with a poor prognosis. The overall survival (OS) depends on the ENSAT stage: in particular in metastatic ACC the OS varies from 10 to 20 months, with a 5-year survival around 10%. ACC has a different behavior, probably due to a different biology. For this reason, a careful prognostic classification is mandatory, in order to stratify the patients and propose a specific management.

EVIDENCE ACQUISITION

Prognostic factors can be divides in three groups: clinical factors (tumor stage, age, hormone-related symptoms), pathological factors (Weiss Score, mitotic count, Ki-67, SF-1 and AVA2, P53, beta-catenin immunohistochemistry, resection status), molecular factors (chromosomal aberrations, methylation profile, altered gene expression and miRNA expression, gene mutations).

EVIDENCE SYNTHESIS

The best way to stratify ACC patients and propose the best therapeutic option is to combine clinical, pathological and molecular factors.

CONCLUSIONS

Individualizing patients' prognosis and tumor biology appears as a necessary step for personalized medicine. In addition to tumor stage and tumor grade, the genomic classification may precise the risk stratification and thus help defining therapeutic strategy.

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.

Challenges in surgical pathology of adrenocortical tumours

Adrenocortical carcinomas are rare tumours that can be diagnostically challenging. Numerous multiparametric scoring systems and diagnostic algorithms have been proposed to differentiate adrenocortical adenoma from adrenocortical carcinoma. Adrenocortical neoplasms must also be differentiated from other primary adrenal tumours, such as phaeochromocytoma and unusual primary adrenal tumours, as well as metastases to the adrenal gland. Myxoid, oncocytic and sarcomatoid variants of adrenocortical tumours must be recognized so that they are not confused with other tumours. The diagnostic criteria for oncocytic adrenocortical carcinoma are different from those for conventional adrenocortical carcinomas. Adrenocortical neoplasms in children are particularly challenging to diagnose, as histological features of malignancy in adrenocortical neoplasms in adults may not be associated with aggressive disease in the tumours of children. Recent histological and immunohistochemical studies and more comprehensive and integrated genomic characterizations continue to advance our understanding of the tumorigenesis of these aggressive neoplasms, and may provide additional diagnostic and prognostic utility and guide the development of therapeutic targets.

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.

Next-generation sequencing reveals microRNA markers of adrenocortical tumors malignancy

Background

Adrenocortical carcinoma is a rare finding among common adrenocortical tumors, but it is highly aggressive and requires early detection and treatment. Still, the differential diagnosis between benign and malignant lesions is difficult even for experienced pathologists and there is a significant need for novel diagnostic methods. In this study we aimed to reveal a complete set of microRNAs expressed in the adrenal gland and to identify easily detectable, stable and objective biomarkers of adrenocortical malignancy.

Methods

We employed next-generation sequencing to analyze microRNA profiles in a unique set of 51 samples, assigned to either a learning dataset including 7 adrenocortical carcinomas (ACCs), 8 adrenocortical adenomas (AAs) and 8 control samples (NAs), or a validation dataset including 8 ACCs, 10 AAs and 10 NAs. The results were validated in real-time Q-PCR.

Results

We detected 411 miRNAs expressed in 1763 length isoforms in the examined samples. Fifteen miRNAs differentiate between malignant (ACC) and non-malignant (AA + NA) tissue in the test set of independent samples. Expression levels of 6 microRNAs, miR-503-5p, miR-483-3p, miR-450a-5p, miR-210, miR-483-5p, miR-421, predict sample status (malignancy/non-malignancy) with at least 95% accuracy in both datasets. The best single-gene malignancy marker, miR-483-3p, has been validated by real-time RT PCR.

Conclusions

As a result of the study we propose clinically valid and easily detectable biomarkers of adrenocortical malignancy that may significantly facilitate morphological examination. Since microRNAs can be detected in blood, the study brings tools for development of non-invasive diagnostics of adrenocortical carcinomas.

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.

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.

Protein Expression of PTTG1 as a Diagnostic Biomarker in Adrenocortical Carcinoma

BACKGROUND

Adrenocortical carcinoma (ACC) has a poor prognosis and there is an unmet clinical need for biomarkers to improve both diagnostic and prognostic assessment. Pituitary-tumor transforming gene (PTTG1) has been shown to modulate cancer invasiveness and response to therapy. The potential role of PTTG1 protein levels in ACC has not been previously addressed. We assessed whether increased nuclear protein expression of PTTG1 distinguished ACCs from adrenocortical adenomas (ACAs).

METHODS

Patients with ACC or ACA were identified from prospective tissue banks at two independent institutions. Two tissue microarrays (TMAs) consisting of adrenal specimens from 131 patients were constructed and clinically annotated. Immunohistochemical analysis for PTTG1 and Ki-67 was performed on each TMA.

RESULTS

TMA-1 (n = 80) contained 20 normal adrenals, 20 ACAs, and 40 ACCs, and the validation, TMA-2 (n = 51), consisted of 10 normal adrenals, 14 ACAs, and 27 ACCs. On TMA-1, nuclear staining of PTTG1 was detected in 12 (31%) ACC specimens, while all ACAs and normal adrenal glands were negative for PTTG1. On TMA-2, 20 (74%) of the ACC tumors demonstrated PTTG1 nuclear staining of PTTG1, and 13 (93%) ACA and 4 (44%) normal adrenal glands were negative for PTTG1. ACC tumors with increased PTTG1 protein staining had a significantly higher Ki-67 index (p < 0.001) than those with lower levels of PTTG1.

CONCLUSIONS

Increased nuclear protein expression of PTTG1 was observed in malignant adrenal tumors. PTTG1 correlated with Ki-67 in two independent TMAs. PTTG1 is a promising biologic marker in the evaluation of adrenal tumors.

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.

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.

Diagnostic and prognostic role of SF1, IGF2, Ki67, p53, adiponectin, and leptin receptors in human adrenal cortical tumors

BACKGROUND

The authors have examined the immunohistochemical expression of several proteins and their relationship with adrenal cortical carcinoma (ACC) diagnosis and progression.

MATERIALS AND METHODS

A total of 83 patients with benign and malignant adrenal cortex tumors operated on in a single center were included in the study. Expression of the following proteins was examined: steroidogenic factor 1 (SF1), insulin growth factor 2 (IGF2), Ki67, p53, as well as adiponectin (Adipo R1, Adipo R2), and leptin (Ob-R) receptors.

RESULTS

Multivariate analysis revealed that the expression of SF1, IGF2, and Adipo R1 and R2 receptors was associated with ACC diagnosis. An acknowledged proliferation marker Ki67 was related with the size of ACC and was an independent ACC diagnosis marker. The authors also assessed the relationship between immunohistochemical parameters and overall survival (OS) and disease progression. Only high IGF2 expression was associated with longer OS (P = 0.025). The most significant one for the prognosis of ACC patients was tumor resectability of the primary tumor. More favorable prognosis was found for young men (P = 0.033).

CONCLUSIONS

The presented data indicate that immunohistochemical assessment (of IGF2, SF1, Adipo R1, and R2 receptors' expression) may be useful in making the diagnosis of uncertain ACC cases.

Preclinical progress and first translational steps for a liposomal chemotherapy protocol against adrenocortical carcinoma

Systemic therapy of adrenocortical carcinoma (ACC) is limited by heterogeneous tumor response and adverse effects. Recently, we demonstrated anti-tumor activity of LEDP-M (etoposide, liposomal doxorubicin, liposomal cisplatin, mitotane), a liposomal variant of EDP-M (etoposide, doxorubicin, cisplatin, mitotane). To improve the therapeutic efficacy and off-target profiles of the clinical gold standard EDP-M, we investigated liposomal EDP-M regimens in different preclinical settings and in a small number of ACC patients with very advanced disease. Short- and long-term experiments were performed on two ACC models (SW-13 and SJ-ACC3) in vivo We evaluated the anti-tumoral effects and off-target profiles of EDP-M, LEDP-M and a novel regimen L(l)EDP-M including liposomal etoposide. Furthermore, the role of plasma microRNA-210 as a therapeutic biomarker and first clinical data were assessed. Classical and liposomal protocols revealed anti-proliferative efficacy against SW-13 (EDP-M P < 0.01; LEDP-M: P < 0.001; L(l)EDP-M: P < 0.001 vs controls), whereas in SJ-ACC3, only EDP-M (P < 0.05 vs controls) was slightly effective. Long-term experiments in SW-13 demonstrated anti-tumor efficacy for all treatment schemes (EDP-M: P < 0.01, LEDP-M: P < 0.05, L(l)EDP-M P < 0.001 vs controls). The analysis of pre-defined criteria leading to study termination revealed significant differences for control (P < 0.0001) and EDP-M (P = 0.003) compared to L(l)EDP-M treatment. Raising its potential for therapy monitoring, we detected elevated levels of circulating microRNA-210 in SW-13 after LEDP-M treatment (P < 0.05). In contrast, no comparable effects were detectable for SJ-ACC3. However, overall histological evaluation demonstrated improved off-target profiles following liposomal regimens. The first clinical data indicate improved tolerability of liposomal EDP-M, thus confirming our results. In summary, liposomal EDP-M regimens represent promising treatment options to improve clinical treatment of ACC.

Could miRNA replacement be a novel therapy for adrenocortical carcinoma?

Adrenocortical carcinoma (ACC) has poor outcomes and there is a need for novel effective treatments for metastatic disease and adjuvant therapy. miRNAs are small endogenous noncoding RNAs that control gene expression. miRNAs are dysregulated in all cancers and manipulation of miRNA levels is under investigation as a novel therapy in other cancers with poor outcomes such as mesothelioma. In this review, the rationale for miRNA therapy will be presented along with the current understanding of the role of miRNA dysregulation and miRNA regulation of ACC. Potential therapeutic approaches of miRNA therapy using established delivery systems such as liposomes and targeted nanocells will be presented, along with the future challenges of establishing miRNA therapy in clinical trials for ACC.

Integrated genome-wide analysis of genomic changes and gene regulation in human adrenocortical tissue samples

To gain insight into the pathogenesis of adrenocortical carcinoma (ACC) and whether there is progression from normal-to-adenoma-to-carcinoma, we performed genome-wide gene expression, gene methylation, microRNA expression and comparative genomic hybridization (CGH) analysis in human adrenocortical tissue (normal, adrenocortical adenomas and ACC) samples. A pairwise comparison of normal, adrenocortical adenomas and ACC gene expression profiles with more than four-fold expression differences and an adjusted P-value < 0.05 revealed no major differences in normal versus adrenocortical adenoma whereas there are 808 and 1085, respectively, dysregulated genes between ACC versus adrenocortical adenoma and ACC versus normal. The majority of the dysregulated genes in ACC were downregulated. By integrating the CGH, gene methylation and expression profiles of potential miRNAs with the gene expression of dysregulated genes, we found that there are higher alterations in ACC versus normal compared to ACC versus adrenocortical adenoma. Importantly, we identified several novel molecular pathways that are associated with dysregulated genes and further experimentally validated that oncostatin m signaling induces caspase 3 dependent apoptosis and suppresses cell proliferation. Finally, we propose that there is higher number of genomic changes from normal-to-adenoma-to-carcinoma and identified oncostatin m signaling as a plausible druggable pathway for therapeutics.

Adrenocortical carcinoma

Recent developments in the treatment of adrenocortical carcinoma (ACC) include diagnostic and prognostic risk stratification algorithms, increasing evidence of the impact of historical therapies on overall survival, and emerging targets from integrated epigenomic and genomic analyses. Advances include proper clinical and molecular characterization of all patients with ACC, standardization of proliferative index analyses, referral of these patients to large cancer referral centers at the time of first surgery, and development of new trials in patients with well-characterized ACC. Networking and progress in the molecular characterization of ACC constitute the basis for significant future therapeutic breakthroughs.

Adrenocortical carcinoma: review of the pathologic features, production of adrenal steroids, and molecular pathogenesis

Adrenocortical carcinoma (ACC) is a malignant neoplasm often associated with an aggressive biological behavior. The histologic differentiation between ACC and adrenocortical adenoma (ACA) is largely determined by employing the Weiss criteria, although this classification may not apply to all the cases. Additionally, various genomic features of ACC could be an auxiliary mode to establish the diagnosis of ACC. Most ACC cases are hormonally functional, and immunohistochemical analysis of steroidogenic enzymes has provided pivotal information as to the analysis of intratumoral production of corticosteroids. This article summarizes the current status of the histopathological diagnosis, molecular pathogenesis, and hormonal features of ACC.

The genetics of adrenocortical tumors

Advances in genomics accelerated greatly progress in the study of the genetics adrenocortical tumors. Bilateral nodular hyperplasias causing Cushing's syndrome are frequently caused by germline alterations leading to cAMP/PKA pathway activation (micronodular) and ARMC5 inactivation (macronodular). Somatic mutations of β-catenin and PRKACA are observed in non secreting or cortisol producing adenomas, respectively. Alterations of the β-catenin (CTNN1B, ZNFR3) or TP53 pathways are found in carcinomas. Mutations in cancers are more common in aggressive tumors and correlate with transcriptome or methylation profiles. Identification of these alterations helps to refine the molecular classification of these tumors and to develop molecular diagnostic tools.

The role of hypoxia-induced miR-210 in cancer progression

Prolonged hypoxia, the event of insufficient oxygen, is known to upregulate tumor development and growth by promoting the formation of a neoplastic environment. The recent discovery that a subset of cellular microRNAs (miRs) are upregulated during hypoxia, where they function to promote tumor development, highlights the importance of hypoxia-induced miRs as targets for continued investigation. miRs are short, non-coding transcripts involved in gene expression and regulation. Under hypoxic conditions, miR-210 becomes highly upregulated in response to hypoxia inducing factors (HIFs). HIF-1α drives miR-210’s overexpression and the resultant alteration of cellular processes, including cell cycle regulation, mitochondria function, apoptosis, angiogenesis and metastasis. Here we discuss hypoxia-induced dysregulation of miR-210 and the resultant changes in miR-210 protein targets that regulate cancer progression. Potential methods of targeting miR-210 as a therapeutic tool are also explored.

MicroRNAs in adrenal tumors: relevance for pathogenesis, diagnosis, and therapy

Several lines of evidence support the relevance of microRNAs in both adrenocortical and adrenomedullary (pheochromocytomas) tumors. Significantly differentially expressed microRNAs have been described among benign and malignant adrenocortical tumors and different forms of pheochromocytomas that might affect different pathogenic pathways. MicroRNAs can be exploited as markers of malignancy or disease recurrence. Besides tissue microRNAs, novel data show that microRNAs are released in body fluids, and blood-borne microRNAs can be envisaged as minimally invasive markers of malignancy or prognosis. MicroRNAs might even serve as treatment targets that could expand the rather-limited therapeutic repertoire in the field of adrenal tumors. In this review, we present a critical synopsis of the recent observations made in the field of adrenal tumor-associated microRNAs regarding their pathogenic, diagnostic, and potential therapeutic relevance.

microRNAs as Potential Biomarkers in Adrenocortical Cancer: Progress and Challenges

Adrenocortical carcinoma (ACC) is a rare malignancy with poor prognosis and limited therapeutic options. Over the last decade, pan-genomic analyses of genetic and epigenetic alterations and genome-wide expression profile studies allowed major advances in the understanding of the molecular genetics of ACC. Besides the well-known dysfunctional molecular pathways in adrenocortical tumors, such as the IGF2 pathway, the Wnt pathway, and TP53, high-throughput technologies enabled a more comprehensive genomic characterization of adrenocortical cancer. Integration of expression profile data with exome sequencing, SNP array analysis, methylation, and microRNA (miRNA) profiling led to the identification of subgroups of malignant tumors with distinct molecular alterations and clinical outcomes. miRNAs post-transcriptionally silence their target gene expression either by degrading mRNA or by inhibiting translation. Although our knowledge of the contribution of deregulated miRNAs to the pathogenesis of ACC is still in its infancy, recent studies support their relevance in gene expression alterations in these tumors. Some miRNAs have been shown to carry potential diagnostic and prognostic values, while others may be good candidates for therapeutic interventions. With the emergence of disease-specific blood-borne miRNAs signatures, analyses of small cohorts of patients with ACC suggest that circulating miRNAs represent promising non-invasive biomarkers of malignancy or recurrence. However, some technical challenges still remain, and most of the miRNAs reported in the literature have not yet been validated in sufficiently powered and longitudinal studies. In this review, we discuss the current knowledge regarding the deregulation of tumor-associated and circulating miRNAs in ACC patients, while emphasizing their potential significance in pathogenic pathways in light of recent insights into the role of miRNAs in shaping the tumor microenvironment.

Assessing Biological Aggression in Adrenocortical Neoplasia

Pathologists are highly skilled at the evaluation of adrenal neoplasms. Occasional adrenocortical tumors can be diagnostically challenging and supplementary tools can assist in these cases. Histologic and molecular studies support a model that includes 2 broad classes of adrenocortical carcinoma with distinct somatic genetic alterations and clinical outcomes. Pathologists should endeavor to grade adrenocortical carcinomas to assign each case into one of these 2 classes. Mitotic grading by mitotic counting and Ki-67 immunohistochemistry represent the most practicable and informative methods currently available.

Expression of miRNAs in non-small-cell lung carcinomas and their association with clinicopathological features

Lung cancer is recognized as a leading cause of cancer-related deaths worldwide. Over the past several years, evidence emerged that microRNAs (miRNAs), a class of small non-coding RNA molecules regulating gene expression at posttranscriptional level, play an important role in cell functioning, as well as in human diseases. Here, we analyzed expression of miR-15a/16, miR-21, miR-34a, miR-126, miR-128, and miR-210 at transcriptional level in 30 non-small-cell lung carcinoma (NSCLC) tumor tissues compared to the matched adjacent normal tissues and their correlation with clinicopathological features of the patients. Samples were collected from the NSCLC patients undergoing surgery before radiotherapeutic or chemotherapeutic treatment. Expression levels of miRNAs were assessed by TaqMan RT-PCR assay. The data obtained in this study were processed using REST 2009 and SPSS statistical software. The graphs were designed by GraphPad prism 5.0. In tumor samples, we found downregulation of miR-15a/16 (50/83.3%), miR-34a (83.3%), miR-126 (70%), and miR-128 (63.3%). At the same time, miR-21 and miR-210 were upregulated by 53.3 and 66.6% in cancer tissue versus matched adjacent normal tissues, respectively. No significant correlation was found between the expression levels of miR-15a/16, miR-21, miR-34a, miR-126, miR-128, and miR-210 and lymph node, tumor size, sex, and smoking. However, the study demonstrated a correlation between a change in expression of miR-15, miR-16, miR-34a, miR-126, and miR-210 compared to normal tissues and TNM staging (P < 0.05). Furthermore, miR-126 expression level was different in adenocarcinomas and squamous cell carcinoma (SCC) subtype (P < 0.1). Detailed analysis revealed significant change in expression of miR-15a/16, miR-34a, miR-126, and miR-210 in NSCLC tumor samples indicating involvement of these miRNAs in lung cancer pathogenesis. miR-210 demonstrated the most consistent increase in tumor tissues between different patients, suggesting its potential significance for NSCLC.