Integrated extracellular microRNA profiling for ovarian cancer screening

Up-regulation of circ_LARP4 suppresses cell proliferation and migration in ovarian cancer by regulating miR-513b-5p/LARP4 axis

Background

Ovarian cancer (OC) is a common fatal malignant tumor of female reproductive system worldwide. Growing studies have proofed that circular RNAs (circRNAs) engage in the regulation of various types of cancers. However, the underlying biological functions and effect mechanism of circular RNA_LARP4 (circ_LARP4) in OC have not been explored.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) analysis was used to detect the expression of circ_LARP4 in OC cells. The function of circ_LARP4 was measured by cell counting kit-8 (CCK-8), colony formation assay and transwell assay. RNA immunoprecipitation (RIP) assay and luciferase reporter assays assessed the binding correlation between miR-513b-5p and circ_LARP4 (or LARP4).

Results

The expression of circ_LARP4 in OC cells was much lower than that in human normal ovarian epithelial cells. Overexpressing circ_LARP4 impaired cell proliferation, invasion and migration abilities. Circ_LARP4 worked as a competing endogenous RNA (ceRNA) to sponge miR-513b-5p. Furthermore, LARP4 was indirectly modulated by circ_LARP4 as the downstream target of miR-513b-5p, as well as the host gene of circ_LARP4.

Conclusion

Circ_LARP4 could hamper cell proliferation and migration by sponging miR-513b-5p to regulate the expression of LARP4. This research may provide some referential value to OC treatment.

MicroRNA-665 promotes the proliferation of ovarian cancer cells by targeting SRCIN1

Recent studies have discovered several microRNAs (miRNAs/miRs) as biomarkers for the prediction of ovarian cancer by detecting miRNA profiles in serum samples from healthy volunteers and patients with ovarian cancer. However, whether and how these miRNAs are involved in tumorigenesis is not known. In the present study, the expression of miR-665, a recently discovered biomarker for ovarian cancer, was upregulated in tumor tissues from patients with ovarian cancer compared with normal tissues. Inhibition of miR-665 inhibited cell proliferation ability and inactivated MAPK/ERK signaling of ovarian cancer cells. Using bioinformatics analysis, Src kinase signaling inhibitor 1 (SRCIN1) was predicted as a potential target gene of miR-665. Reverse transcription-quantitative PCR and western blotting showed that SRCIN1 expression was repressed by miR-665 in ovarian cancer cells. In addition, a dual luciferase activity assay showed that SRCIN1 was a target gene of miR-665. Silencing of SRCIN1 could reverse the cell growth arrest, which was induced by the miR-665 inhibitor. Moreover, miR-665 levels were negatively correlated with SRCIN1 mRNA levels in tumor tissues from patients with ovarian cancer. In conclusion, the present data suggested that miR-665 functioned as an oncogene in ovarian cancer by directly repressing the expression of SRCIN1.

A Circulating miRNA-Based Scoring System Established by WGCNA to Predict Colon Cancer

Introduction

Circulation microRNAs (miRNAs) perform as potential diagnostic biomarkers of many kinds of cancers. This study is aimed at identifying circulation miRNAs as diagnostic biomarkers in colon cancer.

Methods

We conducted a weighted gene coexpression network analysis (WGCNA) in miRNAs to find out the expression pattern among circulation miRNAs by using a “WGCNA” package in R. Correlation analysis was performed to find cancer-related modules. Differentially expressed miRNAs (DEmiRs) in colon cancer were identified by a “limma” package in R. Hub gene analysis was conducted for these DEmiRs in the cancer-related modules by the “closeness” method in cytoscape software. Then, logistic regression was performed to identify the independent risk factors, and a scoring system was constructed based on these independent risk factors. Then, we use data from the GEO database to confirm the reliability of this scoring system.

Results

A total of 9 independent coexpression modules were constructed based on the expression levels of 848 miRNAs by WGCNA. After correlation analysis, green (cor = 0.77, p = 3 × 10^‐25) and yellow (cor = 0.65, p = 6 × 10^‐16) modules were strongly correlated with cancer development. 20 hub genes were found after hub gene analysis in these DEmiRs by cytoscape. Among all these hub genes, hsa-miR-23a-3p (OR = 2.6391, p = 6.23 × 10^‐5) and hsa-miR-663a (OR = 1.4220, p = 0.0069) were identified as an independent risk factor of colon cancer by multivariate regression. Furthermore, a scoring system was built to predict the probability of colon cancer based on both of these miRNAs, the area under the curve (AUC) of which was 0.828. Data from GSE106817 and GSE112264 was used to confirm this scoring system. And the AUC of them was 0.980 and 0.917, respectively.

Conclusion

We built a scoring system based on circulation hub miRNAs found by WGCNA to predict the development of colon cancer.

Peritoneal cancer after bilateral mastectomy, hysterectomy, and bilateral salpingo-oophorectomy with a poor prognosis: A case report and review of the literature

BACKGROUND

Primary peritoneal cancer (PPC) patients with BRCA mutations have a good prognosis; however, for patients with BRCA mutations who are diagnosed with PPC after prophylactic salpingo-oophorectomy (PSO), the prognosis is poor, and survival information is scarce.

CASE SUMMARY

We treated a 56-year-old woman with PPC after bilateral mastectomy, hysterectomy, and bilateral salpingo-oophorectomy. This patient had primary drug resistance and died 12 mo after the diagnosis of PPC. The genetic test performed on this patient indicated the presence of a germline BRCA1 mutation. We searched the PubMed, Scopus, and Cochrane databases and extracted studies of patients with BRCA mutations who developed PPC after PSO. After a detailed literature search, we found 30 cases, 7 of which had a history of breast cancer, 14 of which had no history of breast cancer, and 9 of which had an unknown history. The average age of PSO patients was 48.86 years old (range, 31-64 years). The average time interval between the diagnosis of PPC and preventive surgery was 61.03 mo (range, 12-292 mo). The 2-year survival rate for this patient population was 78.26% (18/23), the 3-year survival rate was 50.00% (9/18), and the 5-year survival rate was 6.25% (1/16).

CONCLUSION

Patients with BRCA mutations who are diagnosed with PPC after preventative surgery have a poor prognosis. Prevention measures and treatments for these patients need more attention.

Serum microRNA profile enables preoperative diagnosis of uterine leiomyosarcoma

Uterine leiomyosarcoma (ULMS) is the major subtype of uterine sarcoma (US) and contributes to uterine cancer deaths. Although preoperative diagnosis of US remains challenging, frequent application of laparoscopic surgery for benign uterine leiomyomas (ULM) requires precise exclusion of US. MicroRNAs are stably present in the bloodstream, and the application of circulating miRNAs as disease biomarkers has been recognized. In the present study, we aimed to identify diagnostic biomarkers for distinguishing US from ULM by focusing on circulating miRNAs. All serum samples were collected preoperatively between 2009 and 2017, and all cases were histopathologically diagnosed. Whole miRNA profiles were obtained using a miRNA microarray. By analyzing expression levels of the miRNAs, candidate miRNAs were selected based on diagnostic performance in discriminating US from ULM, and a diagnostic model was then constructed. A total of 90 serum samples were analyzed, and clustering analyses revealed that the profiles of ULMS were distinct from those of controls. Based on leave-one-out cross-validation, seven miRNAs were selected as biomarker candidates. Based on model construction, the optimal model consisted of two miRNAs (miR-1246 and miR-191-5p), with an area under the receiver operating characteristic curve (AUC) for identifying ULMS of 0.97 (95% confidence interval [CI], 0.91-1.00). In contrast, serum lactate dehydrogenase had an AUC of only 0.64 (95% CI, 0.34-0.94). Seven serum miRNAs with high diagnostic performance for preoperative US screening were detected, and a promising diagnostic model for ULMS was generated.

Microarray profiling identifies extracellular circulating miRNAs dysregulated in cystic fibrosis

Extracellular circulating miRNAs (ECmiRNAs) play a crucial role in cell-to-cell communication and serve as non-invasive biomarkers in a wide range of diseases, but their abundance and functional relevance in cystic fibrosis (CF) remain poorly understood. In this study, we employed microarray technology to identify aberrantly expressed plasma ECmiRNAs in CF and elucidate the functional relevance of their targets. Overall, we captured several ECmiRNAs abundantly expressed in CF. Expression levels of 11 ECmiRNAs differed significantly between CF and healthy control (HC) samples (FDR < 0.05, log2 FC≥2). Among these, 10 were overexpressed while only hsa-miR-598-3p was underexpressed in CF. The overexpressed miRNAs included three let-7 family members (hsa-let-7b-5p, hsa-let-7c-5p and hsa-let-7d-5p), three 103/107 family members (hsa-mir-103a-3p; hsa-mir-103b; hsa-mir-107), hsa-miR-486-5p, and other miRNAs. Using in silico methods, we identified 2,505 validated targets of the 11 differentially expressed miRNAs. Hsa-let-7b-5p was the most important hub in the network analysis. The top-ranked validated targets were involved in miRNA biogenesis and gene expression, including AGO1, DICER1, HMGA1, and MYC. The top pathways influenced by all targets were primarily signal transduction pathways associated with CF, including PI3K/Akt-, Wnt/β catenin-, glucocorticoid receptor-, and mTor signaling pathways. Our results suggest ECmiRNAs may be clinically relevant in CF and warrant further study.

Ovarian cancer cell-secreted exosomal miR-205 promotes metastasis by inducing angiogenesis

Background: By providing oxygen, nutrients and metastatic conduits, tumour angiogenesis is essential for cancer metastasis. Cancer cell-secreted microRNAs can be packaged into exosomes and are implicated in different aspects of tumour angiogenesis. However, the underlying mechanisms are incompletely understood. Methods: The GEPIA database and in situ hybridization assay were used to analyse expression of miR-205 in ovarian tissues. Immunohistochemistry was performed to examine the relationship between miR-205 and microvessel density. Expression of circulating miR-205 was evaluated by RT-PCR and GEO database analysis. Co-culture and exosome labelling experiments were performed to assess exosomal miR-205 transfer from ovarian cancer (OC) cells to endothelial cells ECs. Exosome uptake assays were employed to define the cellular pathways associated with the endocytic uptake of exosomal miR-205. The role of exosomal miR-205 in angiogenesis was further investigated in vivo and in vitro. Western blotting and rescue experiments were applied to detect regulation of the PTEN-AKT pathway by exosomal miR-205 in ECs. Results: miR-205 was up-regulated in OC tissues, and high expression of miR-205 was associated with metastatic progression in OC patients. Moreover, miR-205 was highly enriched in cancer-adjacent ECs, and up-regulation of miR-205 correlated positively with high microvessel density in OC patients. Importantly, miR-205 was markedly enriched in the serum of OC patients, and a high level of miR-205 in circulating exosomes was associated with OC metastasis. In addition, OC-derived miR-205 was secreted into the extracellular space and efficiently transferred to adjacent ECs in an exosome-dependent manner, and the lipid raft-associated pathway plays an important role in regulating uptake of exosomal miR-205. Exosomal miR-205 from OC cells significantly promoted in vitro angiogenesis and accelerated angiogenesis and tumour growth in a mouse model. Furthermore, we found that exosomal miR-205 induces angiogenesis via the PTEN-AKT pathway. Conclusion: These findings demonstrate an exosome-dependent mechanism by which miR-205 derived from cancer cells regulates tumour angiogenesis and implicate exosomal miR-205 as a potential therapeutic target for OC.

Toward the Early Detection of Cancer by Decoding the Epigenetic and Environmental Fingerprints of Cell-Free DNA

Widespread adaptation of liquid biopsy for the early detection of cancer has yet to reach clinical utility. Circulating tumor DNA is commonly detected though the presence of genetic alterations, but only a minor fraction of tumor-derived cell-free DNA (cfDNA) fragments exhibit mutations. The cellular processes occurring in cancer development mark the chromatin. These epigenetic marks are reflected by modifications in the cfDNA methylation, fragment size, and structure. In this review, we describe how going beyond DNA sequence information alone, by analyzing cfDNA epigenetic and immune signatures, boosts the potential of liquid biopsy for the early detection of cancer.

Large-scale rapid detection of circulating microRNAs in plasma for diagnosis and screening of specific diseases

microRNAs are a type of evolutionarily conserved small non-coding RNA with a length of 18-25 nucleotides. In recent years, increasing studies have shown that the content of specific miRNAs in the blood changes significantly during the occurrence and development of major diseases such as cardiovascular disease and cancer. Therefore, miRNAs may serve as important new biomarkers that can be used for disease diagnosis in the future. Here, we improved the polyethylene glycol layer on the surface of a traditional silicon sphere to specifically capture miRNAs by means of a full-function microplate detector, at 100 microliters. The detection limit for specific miRNAs per liter of plasma can reach 1 fM, and simultaneous detection of 96 samples can be achieved. Compared with the traditional real-time PCR technology, our detection eliminates the complex steps of miRNA extraction, reverse transcription, amplification, etc. and avoids more human error in the detection process. Using the full-featured microwell detector, we can rapidly detect specific miRNAs in plasma, which can be used in the diagnosis of cardiovascular diseases in the future.

Circulating miRNA Profiling in Plasma Samples of Ovarian Cancer Patients

Ovarian cancer is one of the most common cancer types in women characterized by a high mortality rate due to lack of early diagnosis. Circulating miRNAs besides being important regulators of cancer development could be potential biomarkers to aid diagnosis. We performed the circulating miRNA expression analysis in plasma samples obtained from ovarian cancer patients stratified into FIGO I, FIGO III, and FIGO IV stages and from healthy females using the NanoString quantitative assay. Forty-five miRNAs were differentially expressed, out of these 17 miRNAs showed significantly different expression between controls and patients, 28 were expressed only in patients, among them 19 were expressed only in FIGO I patients. Differentially expressed miRNAs were ranked by the network-based analysis to assess their importance. Target genes of the differentially expressed miRNAs were identified then functional annotation of the target genes by the GO and KEGG-based enrichment analysis was carried out. A general and an ovary-specific protein–protein interaction network was constructed from target genes. Results of our network and the functional enrichment analysis suggest that besides HSP90AA1, MYC, SP1, BRCA1, RB1, CFTR, STAT3, E2F1, ERBB2, EZH2, and MET genes, additional genes which are enriched in cell cycle regulation, FOXO, TP53, PI-3AKT, AMPK, TGFβ, ERBB signaling pathways and in the regulation of gene expression, proliferation, cellular response to hypoxia, and negative regulation of the apoptotic process, the GO terms have central importance in ovarian cancer development. The aberrantly expressed miRNAs might be considered as potential biomarkers for the diagnosis of ovarian cancer after validation of these results in a larger cohort of ovarian cancer patients.

The NF-κB-modulated miR-19a-3p enhances malignancy of human ovarian cancer cells through inhibition of IGFBP-3 expression

Ovarian cancer is the most lethal gynecologic malignancy due to the lack of symptoms until advanced stages, and new diagnosis and treatment strategy is in urgent need. In this study, we found higher expression of miR-19a-3p in ovarian cancer tissues compared with that in the adjacent normal tissues. By chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA) analysis, we showed that nuclear factor-kappaB (NF-κB) binds to the promoter of miR-19a-3p, leading to reduced expression in ovarian cancer cells. Further study indicated that miR-19a-3p inhibits the expression of insulin-like growth factor binding protein-3 (IGFBP-3), resulting in enhanced growth and migration of ovarian cancer cells in vitro and tumor growth in vivo. These results showed that miR-19a-3p enhances the oncogenesis of ovarian cancer through inhibition of IGFBP-3 expression, and which can be inhibited by NF-κB, suggesting an NF-κB/miR-19a-3p/IGFBP-3 pathway in the oncogenesis of ovarian cancer, which expands our understanding of ovarian cancer and they may contribute to the development of new diagnosis and treatment of ovarian cancer.

Serum microRNA-based prediction of responsiveness to eribulin in metastatic breast cancer

The identification of biomarkers for predicting the responsiveness to eribulin in patients with metastatic breast cancer pretreated with an anthracycline and a taxane remains an unmet need. Here, we established a serum microRNA (miRNA)-based prediction model for the emergence of new distant metastases after eribulin treatment. Serum samples were collected from metastatic breast cancer patients prior to eribulin treatment and comprehensively evaluated by miRNA microarray. The prediction model for estimating eribulin efficacy was established using the logistic LASSO regression model. Serum samples were collected from 147 patients, of which 52 developed at least one new distant metastasis after eribulin monotherapy and 95 did not develop new distant metastases. A combination of eight serum miRNAs (miR-4483, miR-8089, miR-4755-3p, miR-296-3p, miR-575, miR-4710, miR-5698 and miR-3160-5p) predicted the appearance of new distant metastases with an area under the curve of 0.79, sensitivity of 0.69 and specificity of 0.82. The serum levels of miR-8089 and miR-5698 were significantly associated with overall survival after the initiation of eribulin treatment. The present study provides evidence that serum miRNA profiling may serve as a biomarker for the responsiveness to eribulin and for predicting the development of new distant metastases in metastatic breast cancer.

Cerumenogram: a new frontier in cancer diagnosis in humans

Cancer is the deadliest human disease and the development of new diagnosis methods is important to increase the chances of a cure. In this work it was developed a new method, named here for the first time as cerumenogram, using cerumen (earwax) as a new biomatrix for diagnosis. Earwax samples collected from cancer patients (cancer group) and cancer-free patients (control group) were analyzed by Headspace/Gas Chromatography-Mass Spectrometry (HS/GC-MS), following with multivariate analysis steps to process the raw data generated. In total, 158 volatile organic metabolites (VOMs) were identified in the cerumen samples. The 27 selected as potential VOMs biomarkers for cancer provided 100% discrimination between the cancer and control groups. This new test can thus be routinely employed for cancer diagnoses that is non-invasive, fast, cheap, and highly accurate.

In Silico Screening of Circulating MicroRNAs as Potential Biomarkers for the Diagnosis of Ovarian Cancer

Current screening tests for the diagnosis of ovarian cancer (OC) face enduring challenges. However, microRNAs (miRNAs) are stable in the circulation and may be promising molecular biomarkers for OC prediction. Circulating miRNA expression profiles in OC were analyzed using sequencing data from the Gene Expression Omnibus database. Differentially expressed miRNAs were generated from GSE94533, of which some were selected as candidate miRNAs based on an electronic search of the literature and comprehensive evaluation. A meta-analysis was preformed to integrate an evaluation index for these miRNAs in diagnosing OC patients. An independent validation set (GSE106817) was also conducted to further confirm the roles of these miRNAs. We identified four MIR200 members (MIR200A, MIR200B, MIR200C, and MIR429) and MIR25 as being differentially expressed among malignant or benign ovarian tumor patients and healthy controls. In the meta-analysis, these five miRNAs yielded a pooled area under the receiver operating characteristic (ROC) curve (AUC) of 0.78 (sensitivity: 64%, specificity: 88%) in discriminating OC from healthy controls, while the four MIR200 members demonstrated a summary AUC of 0.81 (sensitivity: 92%, specificity: 69%) in differing OC cases from patients with benign disease. In the validation set, differential expression and ROC curve analyses of these miRNAs were consistent except for MIR25. The circulating MIR200 family has the potential to become reliable and noninvasive biomarkers for OC diagnosis. Studies with larger cohorts are warranted to validate the applicability of these miRNAs.

miR‑501‑3p promotes colorectal cancer progression via activation of Wnt/β‑catenin signaling

Aberrant activation of Wnt/β-catenin signaling is observed in >90% of colorectal cancer cases. microRNAs (miRNAs) regulate the expression of key genes in Wnt/β-catenin signaling. As a result, abnormal expression of miRNAs regulates the activation of Wnt/β-catenin signaling in several types of cancer. In the current study, it was demonstrated that miR-501-3p was overexpressed in colorectal tumor tissues compared to the adjacent normal tissues. Downregulation of miR-501-3p inhibited cell proliferation and sphere formation, while it induced cell cycle arrest at the G1 phase in colorectal cancer cells. Bioinformatics analysis results predicted that adenomatous polyposis coli (APC), a negative regulator of Wnt/β-catenin signaling, was a potential target gene of miR-501-3p. Inhibition of miR-501-3p increased APC expression in colorectal cancer cells. Additionally, β-catenin was destabilized following miR-501-3p inhibition; immunofluorescence analysis revealed that β-catenin translocated from nucleus to cytoplasm. In addition, cyclin D1 and c-Myc, two well-characterized target genes of Wnt/β-catenin signaling, were downregulated following miR-501-3p inhibition. Transfection of APC small interfering RNA re-activated β-catenin and stimulated the expression of cyclin D1 and c-Myc. Furthermore, silencing of APC reversed the miR-501-3p inhibitor-induced cell cycle disruption, and the inhibition of cell proliferation and sphere formation in colorectal cancer cells. In conclusion, the present study identified miR-501-3p as a novel regulator of Wnt/β-catenin signaling in colorectal cancer cells via targeting APC, suggesting that miR-501-3p may act as a novel oncogenic miRNA in colorectal cancer.

Facile and Label-Free Electrochemical Biosensors for MicroRNA Detection Based on DNA Origami Nanostructures

MicroRNAs (miRNAs) have emerged as the promising molecular biomarkers for early diagnosis and enhanced understanding of the molecular pathogenesis of cancers as well as certain diseases. Here, a facile, label-free, and amplification-free electrochemical biosensor was developed to detect miRNA by using DNA origami nanostructure-supported DNA probes, with methylene blue (MB) serving as the hybridization redox indicator, for the first time. Specifically, the use of cross-shaped DNA origami nanostructures containing multiple single-stranded DNA probes at preselected locations on each DNA nanostructure could increase the accessibility and the recognition efficiency of the probes (due to the rational controlled density of DNA probes). The successful immobilization of DNA origami probes and their hybridization with targeted miRNA-21 molecules was confirmed by electrochemical impedance spectroscopy and cyclic voltammetry methods. A differential pulse voltammetry technique was employed to record the oxidation peak current of MB before and after target hybridization. The linear detection range of this biosensor was from 0.1 pM to 10.0 nM, with a lower detection limit of 79.8 fM. The selectivity of the miRNA biosensor was also studied by observing the discrimination ability of single-base mismatched sequences. Because of the larger surface area and unprecedented customizability of DNA origami nanostructures, this strategy demonstrated great potential for sensitive, selective, and label-free determination of miRNA for translational biomedical research and clinical applications.

Long non-coding RNA FLJ33360 participates in ovarian cancer progression by sponging miR-30b-3p

Background

Long noncoding RNAs (lncRNAs) have been reported to play a key role in the development and progression of human malignancies. FLJ33360 is an lncRNA with unknown functions. This study was designed to determine the clinical significance and mechanism of FLJ33360 in ovarian cancer.

Materials and methods

The clinical significance of FLJ33360 in ovarian cancer was determined using the Gene Expression Profiling Interactive Analysis (GEPIA) database, Kaplan-Meier Plotter database, quantitative reverse transcription polymerase chain reaction (qRT-PCR) and statistical analysis. The regulatory relationships between FLJ33360 and miR-30b-3p were explored through bioinformatics, the Gene Expression Omnibus (GEO) database, the ArrayExpress database and meta-analysis. The possible pathways were predicted using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. In addition, the key target genes were identified using a protein-protein interaction (PPI) network, the Cancer Genome Atlas (TCGA) database, and correlation analysis.

Results

FLJ33360 expression was significantly downregulated in ovarian cancer tissue (P=0.0011) and was closely associated with International Federation of Gynecology and Obstetrics (FIGO) stage (P=0.027) and recurrence (P=0.002). FLJ33360 may have potential value in detecting ovarian cancer (area under the curve =0.793). Function analysis demonstrated that FLJ33360 can act as a molecular sponge of miR-30b-3p to regulate the expression of target genes that are mainly involved in positive regulation of smooth muscle cell migration, the unsaturated fatty acid metabolic process, and positive regulation of the epithelial to mesenchymal transition. Among these target genes, BCL2 is the hub gene.

Conclusion

FLJ33360 is a potential biomarker for early diagnosis and prognostic assessment in ovarian cancer and may regulate the expression of genes by sponging miR-30b-3p and thus participate in the development of ovarian cancer.

miR-450a Acts as a Tumor Suppressor in Ovarian Cancer by Regulating Energy Metabolism

Dysregulation of miRNA expression is associated with multiple diseases, including cancers, in which small RNAs can have either oncogenic or tumor suppressive functions. Here we investigated the potential tumor suppressive function of miR-450a, one of the most significantly downregulated miRNAs in ovarian cancer. RNA-seq analysis of the ovarian cancer cell line A2780 revealed that overexpression of miR-450a suppressed multiple genes involved in the epithelial-to-mesenchymal transition (EMT). Overexpression of miR-450a reduced tumor migration and invasion and increased anoikis in A2780 and SKOV-3 cell lines and reduced tumor growth in an ovarian tumor xenographic model. Combined AGO-PAR-CLIP and RNA-seq analysis identified a panel of potential miR-450a targets, of which many, including TIMMDC1, MT-ND2, ACO2, and ATP5B, regulate energetic metabolism. Following glutamine withdrawal, miR-450a overexpression decreased mitochondrial membrane potential but increased glucose uptake and viability, characteristics of less invasive ovarian cancer cell lines. In summary, we propose that miR-450a acts as a tumor suppressor in ovarian cancer cells by modulating targets associated with glutaminolysis, which leads to decreased production of lipids, amino acids, and nucleic acids, as well as inhibition of signaling pathways associated with EMT. SIGNIFICANCE: miR-450a limits the metastatic potential of ovarian cancer cells by targeting a set of mitochondrial mRNAs to reduce glycolysis and glutaminolysis.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/13/3294/F1.large.jpg.

Development and Validation of an Esophageal Squamous Cell Carcinoma Detection Model by Large-Scale MicroRNA Profiling

IMPORTANCE

Patients with late-stage esophageal squamous cell carcinoma (ESCC) have a poor prognosis. Noninvasive screening tests using serum microRNAs (miRNAs) to accurately detect early-stage ESCC are needed to improve mortality.

OBJECTIVE

To establish a model using serum miRNAs to distinguish patients with ESCC from noncancer controls.

DESIGN, SETTING, AND PARTICIPANTS

In this case-control study, serum miRNA expression profiles of patients with ESCC (n = 566) and control patients without cancer (n = 4965) were retrospectively analyzed to establish a diagnostic model, which was tested in a training set and confirmed in a validation set. Patients histologically diagnosed as having ESCC who did not receive prior therapy or have a past or concurrent cancer other than ESCC were enrolled from the National Cancer Center Hospital in Tokyo, Japan. Between October 2010 and November 2015, control samples were collected from the National Cancer Center Biobank, the Biobank of the National Center for Geriatrics and Gerontology, and the general population undergoing routine health examination. Data analysis was performed between August 2015 and October 2018. Serum samples were randomly divided into discovery and validation sets.

MAIN OUTCOMES AND MEASURES

The expression of 2565 miRNAs was assessed in each sample. The discriminant model (named the EC index) was evaluated in the training set using Fisher linear discriminant analysis with a greedy algorithm. Receiver operating characteristic curve analysis evaluated the diagnostic ability of the model in the validation set.

RESULTS

In the training set, 283 patients with esophageal cancer (median age, 67 years [range, 37-90 years]; 83.4% male) were compared with 283 control patients (median age, 54 years [range, 22-100 years]; 43.1% male), and the EC index was constructed using 6 miRNAs (miR-8073, miR-6820-5p, miR-6794-5p, miR-3196, miR-744-5p, and miR-6799-5p). The area under the receiver operating characteristic curve was 1.00, with sensitivity of 1.00 and specificity of 0.98. The validation set included 283 patients (median age, 66 years [range, 42-87 years]; 83.0% male) and 4682 control patients (median age, 68 years [range, 20-98 years]; 44.7% male), and the area under the receiver operating characteristic curve for the EC index was 1.00, with sensitivity of 0.96 and specificity of 0.98.

CONCLUSIONS AND RELEVANCE

What appears to be novel serum miRNA discriminant model was developed for the diagnosis of ESCC. A multicenter prospective study is ongoing to confirm the present observations.

MicroRNA-Based Diagnosis and Treatment of Metastatic Human Osteosarcoma

Osteosarcoma is a malignant tumor of the bones that commonly occurs in young individuals. The 5-year survival rate of osteosarcoma patients is 60-70%. Metastasis to the lungs leads to death in 30-40% of osteosarcoma patients. Therefore, the development of effective strategies for early detection and treatment of this disease are important to improve the survival of osteosarcoma patients. However, metastatic markers for osteosarcoma and molecules that might be targeted for the treatment of metastatic osteosarcoma have not been identified yet. Therefore, the mechanism of metastasis to the lungs needs to be explored from a novel viewpoint. Recently, the aberrant expression of microRNAs (miRNAs) has been reported to be involved in the carcinogenesis and cancer progression of many cancers. Furthermore, miRNAs in the blood have been reported to show an aberrant expression unique to several cancers. Therefore, miRNAs are gaining attention as potential diagnostic markers for cancers. On the other hand, normalizing the dysregulated expression of miRNAs in cancer cells has been shown to alter the phenotype of cancer cells, and thus treatment strategies targeting miRNAs are also being considered. This review summarizes the abnormality of miRNA expression associated with the metastasis of osteosarcoma and describes the present situation and issues regarding the early diagnosis and development of treatment strategies for metastatic osteosarcoma based on the current understanding of this disease.