microRNAs as Potential Biomarkers in Adrenocortical Cancer: Progress and Challenges

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.

A benchmark study of deep learning-based multi-omics data fusion methods for cancer

BACKGROUND

A fused method using a combination of multi-omics data enables a comprehensive study of complex biological processes and highlights the interrelationship of relevant biomolecules and their functions. Driven by high-throughput sequencing technologies, several promising deep learning methods have been proposed for fusing multi-omics data generated from a large number of samples.

RESULTS

In this study, 16 representative deep learning methods are comprehensively evaluated on simulated, single-cell, and cancer multi-omics datasets. For each of the datasets, two tasks are designed: classification and clustering. The classification performance is evaluated by using three benchmarking metrics including accuracy, F1 macro, and F1 weighted. Meanwhile, the clustering performance is evaluated by using four benchmarking metrics including the Jaccard index (JI), C-index, silhouette score, and Davies Bouldin score. For the cancer multi-omics datasets, the methods' strength in capturing the association of multi-omics dimensionality reduction results with survival and clinical annotations is further evaluated. The benchmarking results indicate that moGAT achieves the best classification performance. Meanwhile, efmmdVAE, efVAE, and lfmmdVAE show the most promising performance across all complementary contexts in clustering tasks.

CONCLUSIONS

Our benchmarking results not only provide a reference for biomedical researchers to choose appropriate deep learning-based multi-omics data fusion methods, but also suggest the future directions for the development of more effective multi-omics data fusion methods. The deep learning frameworks are available at https://github.com/zhenglinyi/DL-mo .

CASC1 Expression in Bladder Cancer Is Regulated by Exosomal miRNA-150: A Comprehensive Pan-Cancer and Bioinformatics Study

This study explored the role of cancer susceptibility 1 (CASC1) in tumorigenesis and development as well as the key pathways affecting bladder cancer progression. CASC1 was examined in various normal tissues in humans using the HPA database to quantify its expression level and subcellular localization. CASC1 is abundantly expressed in tumor tissues, primarily in cytoplasmic vesicles and stroma. TIMER2 was used to analyze the correlation between CASC1 expression levels and the types of infiltrates associated with immune cells and immunosuppressive cells. MDSC, Treg, M2, and CAF were significantly correlated with CASC1 expression in various tumors. Comparing patients with and without CASC1 mutation, those with CASC1 mutation had worse overall survival, progression-free survival, and disease-free survival. The correlation between has-miR-150 and CASC1 (for the case of bladder cancer) was then analyzed, and the related ceRNA network was mapped. A negative relationship between CASC1 expression and has-miR-150 expression was found in cases of bladder cancer. And the presence of miR-150-targeted CASC1 may be associated with bladder cancer progression. CASC1 is expressed at elevated levels in various tumor tissues, and it is associated with tumorigenesis and development. Exosomes containing miR-150-targeted CASC1 may affect the progression of bladder cancer.

MicroRNA Therapeutics in Cancer: Current Advances and Challenges

Simple Summary

Cancer is a complex disease associated with deregulation of numerous genes. In addition, redundant cellular pathways limit efficiency of monotarget drugs in cancer therapy. MicroRNAs are a class of gene expression regulators, which often function by targeting multiple genes. This feature makes them a double-edged sword (a) as attractive targets for anti-tumor therapy and concomitantly (b) as risky targets due to their potential side effects on healthy tissues. As for conventional antitumor drugs, nanocarriers have been developed to circumvent the problems associated with miRNA delivery to tumors. In this review, we highlight studies that have established the pre-clinical proof-of concept of miRNAs as relevant therapeutic targets in oncology. Particular attention was brought to new strategies based on nanovectorization of miRNAs as well as to the perspectives for their applications.

Abstract

The discovery of microRNAs (miRNAs) in 1993 has challenged the dogma of gene expression regulation. MiRNAs affect most of cellular processes from metabolism, through cell proliferation and differentiation, to cell death. In cancer, deregulated miRNA expression leads to tumor development and progression by promoting acquisition of cancer hallmark traits. The multi-target action of miRNAs, which enable regulation of entire signaling networks, makes them attractive tools for the development of anti-cancer therapies. Hence, supplementing downregulated miRNA by synthetic oligonucleotides or silencing overexpressed miRNAs through artificial antagonists became a common strategy in cancer research. However, the ultimate success of miRNA therapeutics will depend on solving pharmacokinetic and targeted delivery issues. The development of a number of nanocarrier-based platforms holds significant promises to enhance the cell specific controlled delivery and safety profile of miRNA-based therapies. In this review, we provide among the most comprehensive assessments to date of promising nanomedicine platforms that have been tested preclinically, pertaining to the treatment of selected solid tumors including lung, liver, breast, and glioblastoma tumors as well as endocrine malignancies. The future challenges and potential applications in clinical oncology are discussed.

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.

Multi-dimensional data integration algorithm based on random walk with restart

BACKGROUND

The accumulation of various multi-omics data and computational approaches for data integration can accelerate the development of precision medicine. However, the algorithm development for multi-omics data integration remains a pressing challenge.

RESULTS

Here, we propose a multi-omics data integration algorithm based on random walk with restart (RWR) on multiplex network. We call the resulting methodology Random Walk with Restart for multi-dimensional data Fusion (RWRF). RWRF uses similarity network of samples as the basis for integration. It constructs the similarity network for each data type and then connects corresponding samples of multiple similarity networks to create a multiplex sample network. By applying RWR on the multiplex network, RWRF uses stationary probability distribution to fuse similarity networks. We applied RWRF to The Cancer Genome Atlas (TCGA) data to identify subtypes in different cancer data sets. Three types of data (mRNA expression, DNA methylation, and microRNA expression data) are integrated and network clustering is conducted. Experiment results show that RWRF performs better than single data type analysis and previous integrative methods.

CONCLUSIONS

RWRF provides powerful support to users to decipher the cancer molecular subtypes, thus may benefit precision treatment of specific patients in clinical practice.

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.

The Role of Biomarkers in Adrenocortical Carcinoma: A Review of Current Evidence and Future Perspectives

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy arising from the adrenal cortex often with unexpected biological behavior. It can occur at any age, with two peaks of incidence: in the first and between fifth and seventh decades of life. Although ACC are mostly hormonally active, precursors and metabolites, rather than end products of steroidogenesis are produced by dedifferentiated and immature malignant cells. Distinguishing the etiology of adrenal mass, between benign adenomas, which are quite frequent in general population, and malignant carcinomas with dismal prognosis is often unfeasible. Even after pathohistological analysis, diagnosis of adrenocortical carcinomas is not always straightforward and represents a great challenge for experienced and multidisciplinary expert teams. No single imaging method, hormonal work-up or immunohistochemical labelling can definitively prove the diagnosis of ACC. Over several decades' great efforts have been made in finding novel reliable and available diagnostic and prognostic factors including steroid metabolome profiling or target gene identification. Despite these achievements, the 5-year mortality rate still accounts for approximately 75% to 90%, ACC is frequently diagnosed in advanced stages and therapeutic options are unfortunately limited. Therefore, imperative is to identify new biological markers that can predict patient prognosis and provide new therapeutic options.

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.

Aberrant DNA methylation of synaptophysin is involved in adrenal cortisol-producing adenoma

Cortisol-producing adenoma (CPA) is the main cause of Adrenal Cushing syndrome. However, its molecular mechanism is not fully understood. Previous study revealed Synaptophysin (SYP) is ubiquitously expressed in adrenocortical tumors, but its function in CPA still need to be discovered. In the present study we determine the molecular mechanism involved in SYP dysregulation in CPA and how SYP affects the secretion of cortisol in CPA. Our results showed that aberrant DNA methylation of SYP is involved in CPA progress. Using a miRNA microarray and qRT-PCR, we found decreased expression of miR-27a-5p in CPA compared with normal adrenal tissue. Moreover, the expression of TET3, the target gene of miR-27a-5p, increased in CPA compared with normal adrenal tissue. Knock-down of TET3 resulted in hypermethylation of SYP which reducing the expression level of SYP in H295R cells. The miR-27a-5p-TET3-SYP signalling pathway may regulate proliferation and cortisol secretion in H295R cells and, thus, play a key role in CPA development.

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.

MicroRNAs in endocrine tumors

MicroRNAs (miRNAs) are small, protein noncoding RNAs that regulate gene expression post-transcriptionally. Their role is considered to set the gene expression to the optimal level, or in other words to provide "fine tuning" of gene expression. They regulate essential physiological processes such as differentiation, cell growth, apoptosis and their role is known in tumor development too. At tissue level differential miRNA expression in endocrine disorders including endocrine malignancies has also been reported. A new era of miRNAs-related research started when miRNAs were successfully detected outside of cells, in biofluids, in cell-free environments. Their significant role has been demonstrated in cell-cell communication in tumor biology. Due to their stability circulating miRNAs can serve as potential biomarkers. In common diseases circulating miRNAs can be potentially proposed as screening biomarkers and they are also useful to detect tumor recurrence hence they can be applied in post-surgery follow-up too. MiRNAs as diagnostic markers can also be helpful at tissue level when certain histology diagnosis is challenging. Beside diagnosis, tissue miRNAs have the potential to predict prognosis. Intensive research is carried out regarding endocrine tumors as well in terms of miRNAs. However, until now miRNAs as biomarkers do not applied in routine diagnostics, probably due to the challenging preanalytics. In this review we summarized tissue and circulating miRNAs found in thyroid, adrenal, pituitary and neuroendocrine tumors. We aimed to highlight the most important, selected miRNAs with potential diagnostic and prognostic value both in tissue and circulation. Common miRNAs across different endocrine neoplasms are summarized and miRNAs enriched at 14q31 locus are also highlighted suggesting their general role in tumorigenesis of endocrine glands.

Apoptosis regulation in adrenocortical carcinoma

Apoptosis evading is a hallmark of cancer. Tumor cells are characterized by having an impaired apoptosis signaling, a fact that deregulates the balance between cell death and survival, leading to tumor development, invasion and resistance to treatment. In general, patients with adrenocortical carcinomas (ACC) have an extremely bad prognosis, which is related to disease progression and significant resistance to treatments. In this report, we performed an integrative review about the disruption of apoptosis in ACC that may underlie the characteristic poor prognosis in these patients. Although the apoptosis has been scarcely studied in ACC, the majority of the deregulation phenomena already described are anti-apoptotic. Most importantly, in a near future, targeting apoptosis modulation in ACC patients may become a promising therapeutic.

Identification of four hub genes associated with adrenocortical carcinoma progression by WGCNA

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare and aggressive malignant cancer in the adrenal cortex with poor prognosis. Though previous research has attempted to elucidate the progression of ACC, its molecular mechanism remains poorly understood.

METHODS

Gene transcripts per million (TPM) data were downloaded from the UCSC Xena database, which included ACC (The Cancer Genome Atlas, n = 77) and normal samples (Genotype Tissue Expression, n = 128). We used weighted gene co-expression network analysis to identify gene connections. Overall survival (OS) was determined using the univariate Cox model. A protein-protein interaction (PPI) network was constructed by the search tool for the retrieval of interacting genes.

RESULTS

To determine the critical genes involved in ACC progression, we obtained 2,953 significantly differentially expressed genes and nine modules. Among them, the blue module demonstrated significant correlation with the "Stage" of ACC. Enrichment analysis revealed that genes in the blue module were mainly enriched in cell division, cell cycle, and DNA replication. Combined with the PPI and co-expression networks, we identified four hub genes (i.e., TOP2A, TTK, CHEK1, and CENPA) that were highly expressed in ACC and negatively correlated with OS. Thus, these identified genes may play important roles in the progression of ACC and serve as potential biomarkers for future diagnosis.

Circulating MiR-210 and MiR-1246 as Potential Biomarkers for Differentiating Hepatocellular Carcinoma from Metastatic Tumors in the Liver

Background

To date few reports have pointed out the role of circulating miRNAs in discriminating metastatic liver tumors from primary hepatocellular (HCC) tumors. Such discrimination will have significant therapeutic and prognostic implications. The purpose of this study was to evaluate the potential value of a panel of HCC-related circulating miRNAs (miR-142, miR-182, miR-200a, mir-210, miR-211, miR-302b, miR-324, miR-338, miR-340 and miR-1246) as noninvasive biomarkers for discriminating primary HCC from metastatic tumors in the liver.

Methods

The expression level of the selected miRNAs was quantified by quantitative real time PCR in 33 patients with HCC, 22 patients with metastatic tumors in the liver, and 30 healthy volunteers as control. Mann-Whitney U test was used to evaluate the difference in miRNAs expression between primary and metastatic liver tumors and to study the associations between their relative expression levels and the clinicopathological factors. Receiver operating characteristic curve was used to evaluate the diagnostic value of the individual miRNAs.

Results

Statistical analyses revealed a differential expression in the level of serum miR-210 and miR-1246 between the two groups of patients. The sensitivity and specificity of miR-210, for differentiating HCC from metastatic malignancies in the liver were found to be 73.7% and 64.28%, respectively. Whilst, of miR-1246 were 72.2% and 67.8%, respectively. In addition, the differential expression of the two miRNAs was also found to be associated with clinicopathological parameters in the two studied groups.

Conclusions

Serum miR-210 and miR-1246 have some diagnostic value for discriminating patients with metastatic tumors to patients with primary HCC

The human adrenal cortex: growth control and disorders

This review summarizes key knowledge regarding the development, growth, and growth disorders of the adrenal cortex from a molecular perspective. The adrenal gland consists of two distinct regions: the cortex and the medulla. During embryological development and transition to the adult adrenal gland, the adrenal cortex acquires three different structural and functional zones. Significant progress has been made in understanding the signaling and molecules involved during adrenal cortex zonation. Equally significant is the knowledge obtained regarding the action of peptide factors involved in the maintenance of zonation of the adrenal cortex, such as peptides derived from proopiomelanocortin processing, adrenocorticotropin and N-terminal proopiomelanocortin. Findings regarding the development, maintenance and growth of the adrenal cortex and the molecular factors involved has improved the scientific understanding of disorders that affect adrenal cortex growth. Hypoplasia, hyperplasia and adrenocortical tumors, including adult and pediatric adrenocortical adenomas and carcinomas, are described together with findings regarding molecular and pathway alterations. Comprehensive genomic analyses of adrenocortical tumors have shown gene expression profiles associated with malignancy as well as methylation alterations and the involvement of miRNAs. These findings provide a new perspective on the diagnosis, therapeutic possibilities and prognosis of adrenocortical disorders.

A comprehensive evaluation for polymorphisms in let-7 family in cancer risk and prognosis: a system review and meta-analysis

miRNA polymorphisms had potential to be biomarkers for cancer susceptibility and prognosis. The mature miRNA-let-7 family was considered as the most important miRNA for the cancer incidence and progression. Recently, the promising let-7 miRNAs were reported to be associated with various cancers, but the results were inconsistent. We performed a first-reported systematic review with a meta-analysis for the association of let-7 family single nucleotide polymorphisms (SNPs) with cancer risk/prognosis. Ten studies were included with a total of 3878 cancer cases and 4725 controls for the risk study and 1665 cancer patients for the prognosis study in this meta-analysis. In the risk study, the let-7i rs10877887 and let-7a-1/let-7f-1/let-7d rs13293512 were shown no significant association for the overall cancer risk. In the stratified analysis, the rs10877887 variant genotype was significantly associated with a decreased cancer risk in head and neck cancer (TC compared with TT: P=0.017; odds ratio (OR) = 0.81; TC + CC compared with TT: P=0.020; OR = 0.82). In the prognosis study, the let-7i rs10877887 SNP was shown to be associated with a higher risk for cancer prognosis in the dominate model (P=0.004; hazard ratio (HR) = 1.32). The other two SNPs (let-7a-1 rs10739971 and let-7a-2 rs629367) were not found to be associated with cancer survival. None of the let-7 family polymorphisms had potential to be biomarkers for cancer susceptibility but let-7i rs10877887 SNP had potential to be predicting markers for cancer prognosis. In the future, large-sample studies are still needed to verify our findings.

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.

MicroRNA-10a/b are regulators of myeloid differentiation and acute myeloid leukemia

MicroRNAs (miRs) have been demonstrated to perform important roles in normal hematopoiesis and leukemogenesis. Accumulating evidence suggests that miR-10a and miR-10b may behave as novel oncogenes or tumor suppressors in human cancer. The present study reported the function of the miR-10 family in myeloid differentiation and acute myeloid leukemia (AML). The levels of miR-10a/b expression were increased in AML cases compared with normal controls, particularly in M1, M2 and M3 subtypes. The levels of miR-10a/b expression were also upregulated in patients with nucleophosmin-mutated AML and AML patients with t(8;21) and t(9;11), compared with the normal control. In addition, the role of miR-10a/b in regulating myeloid differentiation and leukemogenesis was investigated. The results indicated that miR-10a/b expression was able to promote the proliferation of human promyelocytic leukemia cells, while suppressing the granulocytic and monocytic differentiation of the leukemia cells. These findings suggested that abnormal high expression of miR-10a/b may result in unlimited proliferation of immature blood progenitors and repression of mature blood cell differentiation and maturation, thus leading to the occurrence of AML. miR-10a/b may be developed as novel therapeutic targets for the treatment of AML.

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.

MiR-196a2 and lung cancer in Chinese non-smoking females: a genetic association study and expression analysis

Background

The common polymorphism rs11614913 in miR-196a2 might be associated with lung cancer risk for non-smoking females in northeast China.

Methods

The genotypes of rs11614913 in miR-196a2 were determined by a case-control study including 1003 patients with lung cancer and 1003 healthy controls. The tissues were detected to assess the miRNA expression. Secondary structures of miR-196a2 were predicted.

Results

There was a significant association between miR-196a2 rs11614913 and lung cancer risk in Chinese non-smoking females. Individuals carrying TC or CC genotype had increased risk of lung cancer compared with TT genotype (adjusted risks were 1.63 and 1.67). The C allele was associated with a higher risk of lung cancer with a significant risk of 1.27. The similar significant results were also found in lung adenocarcinoma. There was a significant association between miR-196a2 expression and lung cancer risk (t=2.594, P=0.012). The relative expression of miR-196a2 was significantly higher for CC genotype comparing with the CT or TT genotype in tumor tissues (P values were all 0.003). The optimal free energies were different for T allele and C allele.

Conclusions

The polymorphism rs11614913 in miR-196a2 may be associated with lung cancer risks in Chinese non-smoking females through affecting miR-196a2 expression and secondary structure.

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.

Epigenetic dysregulation of brainstem nuclei in the pathogenesis of Alzheimer's disease: looking in the correct place at the right time?

Even though the etiology of Alzheimer's disease (AD) remains unknown, it is suggested that an interplay among genetic, epigenetic and environmental factors is involved. An increasing body of evidence pinpoints that dysregulation in the epigenetic machinery plays a role in AD. Recent developments in genomic technologies have allowed for high throughput interrogation of the epigenome, and epigenome-wide association studies have already identified unique epigenetic signatures for AD in the cortex. Considerable evidence suggests that early dysregulation in the brainstem, more specifically in the raphe nuclei and the locus coeruleus, accounts for the most incipient, non-cognitive symptomatology, indicating a potential causal relationship with the pathogenesis of AD. Here we review the advancements in epigenomic technologies and their application to the AD research field, particularly with relevance to the brainstem. In this respect, we propose the assessment of epigenetic signatures in the brainstem as the cornerstone of interrogating causality in AD. Understanding how epigenetic dysregulation in the brainstem contributes to AD susceptibility could be of pivotal importance for understanding the etiology of the disease and for the development of novel diagnostic and therapeutic strategies.

Antiproliferative and Pro-Apoptotic Effects of MiR-4286 Inhibition in Melanoma Cells

INTRODUCTION

MicroRNAs are essential regulators of gene expression at the post-transcriptional level. Their expression is altered in cancer tissues, and evaluation of these alterations is considered a promising tool used to diagnose and identify prognostic markers.

MATERIALS AND METHODS

The microRNA expression profiles of formalin-fixed, paraffin-embedded melanoma and melanocytic nevi samples were estimated with a microarray and subsequently validated by real-time PCR. Melanoma cells were transfected with miR-4286 inhibitor to evaluate the influence of this microRNA on the viability, proliferation, apoptosis, migration, and invasion of melanoma cells.

RESULTS

The microarray revealed that the expression of 1,171 microRNAs was altered in melanoma samples compared to melanocytic nevi. Real-time PCR validation experiments found the microRNA expression levels to correspond to the melanoma/melanocytic nevi microarray results. The pathway analysis identified 52 modulated pathways in melanoma. Moreover, the application of miR-4286 inhibitor to BRO melanoma cells resulted in a 2.6-fold increase in the apoptosis rate and a 1.7-fold decrease in the cell proliferation/viability but did not affect the invasiveness and migration of these cells. Furthermore, the use of miR-4286 inhibitor altered the mRNA expression of several miR-4286 gene targets: folylpolyglutamate synthase, RNA polymerase I-specific transcription initiation factor, apelin, G-protein-coupled receptor 55, and high-mobility group A1 protein, which have been implicated in cell proliferation/apoptosis regulation. Lastly, the transiently transfected SK-MEL-1 cells with miR-4286 inhibitor decreased proliferation rate and modulated folylpolyglutamate synthase rates of these cells.

CONCLUSION

Our results demonstrate that miR-4286 mediates proliferation and apoptosis in melanoma cells, these findings may represent a novel mechanism underlying these processes.

Technological advances in precision medicine and drug development

New technologies are rapidly becoming available to expand the arsenal of tools accessible for precision medicine and to support the development of new therapeutics. Advances in liquid biopsies, which analyze cells, DNA, RNA, proteins, or vesicles isolated from the blood, have gained particular interest for their uses in acquiring information reflecting the biology of tumors and metastatic tissues. Through advancements in DNA sequencing that have merged unprecedented accuracy with affordable cost, personalized treatments based on genetic variations are becoming a real possibility. Extraordinary progress has been achieved in the development of biological therapies aimed to even further advance personalized treatments. We provide a summary of current and future applications of blood based liquid biopsies and how new technologies are utilized for the development of biological therapeutic treatments. We discuss current and future sequencing methods with an emphasis on how technological advances will support the progress in the field of precision medicine.

Prognostic Factors for Adrenocortical Carcinoma Outcomes

PURPOSE

Adrenocortical carcinoma (ACC) is an aggressive tumor characterized by a high recurrence rate and poor response to treatment. This study analyzes a consecutive series of ACC patients to evaluate the prognostic value of various clinical and pathological characteristics.

METHODS

We retrospectively evaluated 32 ACC patients followed at our Medical Center from 1997 to 2015 and evaluated the prognostic value of age at diagnosis, gender, tumor functional status, stage, and type of treatment with respect to overall survival (OS) and disease-free survival (DFS), as determined by Kaplan-Meier curves.

RESULTS

ACC was associated with hormonal overproduction in 50% of cases, and patients with isolated hyperandrogenism had a better prognosis. Recurrence was observed in 12/26 (46.2%) patients with no evidence of disease after surgery. Tumor size [hazard ratio (HR) 1.32, 95% confidential intervals (CI) 1.12-1.64; p = 0.007], ki-67 (HR 1.06, 95% CI 1.02-1.11; p = 0.009) and advanced stage at diagnosis (III-IV) (HR 6.51, 95% CI 1.65-24.68; p = 0.006) were associated with recurrence in the 26 R0 patients in the univariate analysis. Advanced stage was an independent risk factor for recurrence in the multivariate analysis (HR 8.10, 95% CI 1.55-41.35; p = 0.01). Five-year survival was 40.0%. Positive resection margins (HR 10.61, 95% CI 3.02-38.31; p = < 0.001), ki-67 (HR 1.04, 95% CI 1.01-1.07; p = 0.01) and advanced stage (HR 11.31, 95% CI 1.45-87.76; p = 0.02) were associated with poor survival in all 32 patients, but only positive resection margins were an independent predictor of mortality in the multivariate analysis (HR 6.22, 95% CI 1.44-26.05; p = 0.01).

CONCLUSION

ACC has a poor prognosis with a high recurrence rate. Tumor stage at diagnosis and the completeness of surgical excision are the most relevant prognostic factors.

Involvement of upregulation of miR-210 in a rat epilepsy model

Epilepsy is a common type of neurological disorder with complex etiology. The mechanisms are still not clear. MicroRNAs are endogenous noncoding RNAs with many physiological activities. Multiple microRNAs were abnormally expressed in status epilepticus, including miR-210. In this study, we applied lithium chloride and pilocarpine to induce epileptic activity and aimed to disclose the potential mechanisms. Our data showed that miR-210 was significantly upregulated in hippocampus one day after modeling (P<0.05 vs control) and the high expression of miR-210 lasted for at least 30 days. By contrast, γ-aminobutyric acid (GABA) level significantly decreased concurrently after modeling (P<0.05 vs control). To question whether miR-210 could be a potential therapeutic target for epilepsy, miR-210 inhibitor was administrated through intrahippocampal injection after epilepsy modeling. Our data showed that morphological changes of hippocampal neurons and apoptosis triggered by epilepsy were mitigated by miR-210 inhibition. More importantly, the expressions of GABA-related proteins, including GABAA receptor α1, glutamate decarboxylase, and GABA transporter 1, were significantly elevated after epilepsy modeling in both mRNA and protein levels 3 days postmodeling (P<0.05 vs control), which were mitigated by miR-210 inhibitor treatment (P<0.05 vs model). In addition, epilepsy-induced upregulation of GABA transaminase was alleviated by miR-210 inhibitor. Taken together, these data implicated potential roles of miR-210 in lithium chloride-pilocarpine-induced epilepsy model and miR-210 could serve as a potential therapeutic target in status epilepticus.