MicroRNA-205 suppresses the growth of adrenocortical carcinoma SW-13 cells via targeting Bcl-2

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.

The potential role of miRNAs in the pathogenesis of adrenocortical carcinoma - A focus on signaling pathways interplay

Adrenocortical carcinoma (ACC) is a highly malignant infrequent tumor with a dismal prognosis. microRNAs (miRNAs, miRs) are crucial in post-transcriptional gene expression regulation. Due to their ability to regulate multiple gene networks, miRNAs are central to the hallmarks of cancer, including sustained proliferative signaling, evasion of growth suppressors, resistance to cell death, replicative immortality, induction/access to the vasculature, activation of invasion and metastasis, reprogramming of cellular metabolism, and avoidance of immune destruction. ACC represents a singular form of neoplasia associated with aberrations in the expression of evolutionarily conserved short, non-coding RNAs. Recently, the role of miRNAs in ACC has been examined extensively despite the disease's rarity. Hence, the current review is a fast-intensive track elucidating the potential role of miRNAs in the pathogenesis of ACC besides their association with the survival of ACC.

What is the role of CHCHD2 in adrenal tumourigenesis?

PURPOSE

CHCHD2 is an antiapoptotic mitochondrial protein acting through the BCL2/BAX pathway in various cancers. However, data on the regulatory role of CHCHD2 in adrenal tumourigenesis are scarce.

METHODS

We studied the expression of CHCHD2, BCL2, and BAX in human adrenocortical tissues and SW13 cells. mRNA and protein levels were analyzed through qPCR and immunoblotting, respectively, in 16 benign adrenocortical neoplasms (BANs), along with their adjacent normal adrenal tissues (controls), and 10 adrenocortical carcinomas (ACCs). BCL2/BAX mRNA expression was also analyzed in SW13 cells after CHCHD2 silencing. MTS, flow cytometry and scratch assays were performed to assess cell viability, apoptosis, and invasion, respectively.

RESULTS

BCL2 and CHCHCD2 mRNA and protein expression was increased in BANs compared to normal adrenal tissues whereas BAX was decreased. BAX and CHCHD2 mRNA and protein levels were significantly downregulated and upregulated, respectively, in ACCs compared with either BANs or controls. Expression of the studied genes was not different among cortisol-secreting and nonfunctional ACAs. No significant association was found between genes' expression and other established prognostic markers of ACCs patients. In vitro analysis showed that CHCHD2 silencing resulted in reduced cell viability and invasion as well as increased SW13 cells apoptosis.

CONCLUSIONS

CHCHD2 expression seems to be implicated in adrenal tumourigenesis and its absence resulted to increased apoptosis in vitro. However, the exact mechanism of action and particularly its association with the BAX/BCL2 pathway needs to be further studied and evaluate whether it could be a protentional therapeutic target.

Diagnostics and Therapeutic Potential of miR-205 and miR-34a in Ovarian Cancer Management: A miRNA-Target-Based Analysis

Epithelial ovarian cancer (EOC) treatment strategies mainly focused on surgery combined with chemotherapy. Recent targeted therapy techniques emerge as milestone and could be used for management of ovarian cancer (OC) progression with more efficacy. The aim is to evaluate the therapeutic and diagnostic potential of microRNA (miRNA) in management of EOC using in silico and quantitative real-time PCR (qRT-PCR) expression analysis. We performed functional enrichment and miRNA-Target genes expression analysis in 48 EOC and 22 normal tissue samples using qRT-PCR and correlated with miRNA expression data in matched samples to evaluate the diagnostic and therapeutic potential of miRNA in OC management. In silico functional enrichment analysis revealed miRNA association with disease. Target genes of miRNAs participate in several biologically important pathways leading to cancer progression. Targets of miRNA-205 and miRNA-34a were significantly downregulated, and upregulated, respectively, in EOC. Moreover, significant negative correlation between relative expression of miRNA-205 and target genes (BCL2, ZEB1, E2F1, and TP53) was observed with r = -0.813; r = -0.755; r = -0.559; and r = -0.767, respectively. Similarly, miRNA-34a also showed higher negative correlation with target genes (MDM4, MAPK3, BRCA1, AREG) with r = -0.840; r = -0.870; r = -0.622; and r = -0.623, respectively. In addition, receiver operating characteristics analysis of combined miRNA panel, miRNA-205-Target gene panel, and miRNA-34a-Target gene panel exhibited higher diagnostics value with area under the curve (AUC) of 92.7 (p < 0.0001), 94.8 (p < 0.0001), and 98.3 (p < 0.0001), respectively. Negative Correlation between miRNA and target genes expression data in matched samples highlights therapeutic potential of miRNA in EOC management. Moreover, combined diagnostic potential of miRNA-target gene panel could predict risk of EOC with higher AUC, sensitivity, and specificity.

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

Simple Summary

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

Abstract

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

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

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

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.

Advantages of Restoring miR-205-3p Expression for Better Prognosis of Gastric Cancer via Prevention of Epithelial-mesenchymal Transition

Purpose

miR-205 is a tumor suppressor and plays an important role in tumor invasiveness. However, the role of miR-205 in human gastric cancer (GC) epithelial-mesenchymal transition (EMT) remains unclear. The aim of this study was to investigate the molecular mechanism of miR-205 in the regulation of EMT in GC invasion.

Materials and Methods

Quantitative polymerase chain reaction (qPCR) was used to detect the expression of miR-205 in GC. Further, the correlation between the pathological parameters and prognosis of GC was statistically analyzed. A transwell model was used to evaluate the effect of miR-205-3p on the invasion and migration of GC cells. qPCR, western blotting, and luciferase assay were performed to analyze the relationship and target effects between miR-205-3p and the expression of zinc finger electron box binding homologous box 1 (ZEB1) and 2 (ZEB2).

Results

We found that the levels of miR-205-3p were significantly lower (P<0.05) in GC tissues than in matched normal tissues. Additionally, the expression of miR-205-3p was related to the tumor invasion depth, lymph node metastasis, lymph node invasion, and tumor, node, metastasis stage. Patients with lower miR-205-3p expression levels in the tumors had a poorer prognosis. The in vitro assays indicated that miR-205-3p could affect the invasion ability and EMT of GC cells by targeting the expression of both ZEB1 and ZEB2.

Conclusions

miR-205-3p promotes GC progression and affects the prognosis of patients by targeting both ZEB1 and ZEB2 to directly influence EMT.

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.

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.

LIMK2 acts as an oncogene in bladder cancer and its functional SNP in the microRNA-135a binding site affects bladder cancer risk

LIM kinases modulate multiple aspects of cancer development, including cell proliferation and survival. As the mechanisms of LIMK-associated tumorigenesis are still unclear, we analyzed the tumorigenic functions of LIM kinase 2 (LIMK2) in human bladder cancer (BC) and explored whether the newly identified LIMK2 3´-UTR SNP rs2073859 (G-to-A allele) is correlated with clinical features. Expression levels of LIMK2 in 38 human BC tissues and eight cell lines were examined using quantitative real-time PCR and immunohistochemistry. LIMK2 was overexpressed in most BC tissues (27/38, 71%) and BC-derived cell lines (6/8), and was more frequently overexpessed in high-grade than low-grade BC (80% vs. 47%). The effects of LIMK2 on BC cell proliferation, survival and migration, were studied by overexpression and RNA interference approaches in vitro and in vivo. LIMK2 overexpression promoted proliferation, migration and invasion of BC cells, while LIMK2 depletion inhibited cell invasion and viability and induced growth arrest in vitro and in vivo. PCR-Restriction Fragment Length Polymorphism (RFLP) was used to genotype LIMK2 SNP rs2073859 and multivariate logistic regression applied to assess the relationship between allele frequency and clinical features in 139 BC patients. Functional analyses localized SNP rs2073859 within the microRNA-135a seed-binding region and revealed significantly lower LIMK2 G allele expression. The frequency of A genotypes (AG + AA) was higher in the BC group than normal controls and correlated with risks of high-grade and high-stage BC. In conclusion, LIMK2 may function as an oncogene in human BC, while allele-specific regulation by microRNA-135a may influence disease risk.

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.

Role of microRNAs in endocrine cancer metastasis

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

Translational applications of microRNAs in cancer, and therapeutic implications

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

Cancer Hallmarks and MicroRNAs: The Therapeutic Connection

Human cancers are characterized by a number of hallmarks, including sustained proliferative signaling, evasion of growth suppressors, activated invasion and metastasis, replicative immortality, angiogenesis, resistance to cell death, and evasion of immune destruction. As microRNAs (miRNAs) are deregulated in virtually all human cancers, they show involvement in each of the cancer hallmarks as well. In this chapter, we describe the involvement of miRNAs in cancer from a cancer hallmarks and targeted therapeutics point of view. As no miRNA-based cancer therapeutics are available to date, and the only clinical trial on miRNA-based cancer therapeutics (MRX34) was terminated prematurely due to serious adverse events, we are focusing on protein-coding miRNA targets for which targeted therapeutics in oncology are already approved by the FDA. For each of the cancer hallmarks, we selected major protein-coding players and describe the miRNAs that target them.

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.