Cell-free miRNAs as non-invasive biomarkers in breast cancer: Significance in early diagnosis and metastasis prediction

Sensitive fluorescence detection of miRNA-124 in cardiomyocytes under oxidative stress using a nucleic acid probe

MicroRNAs (miRNAs) are small noncoding RNAs of 18-25 bases. miRNAs are also important new biomarkers that can be used for disease diagnosis in the future. Studies have shown that miR-124 levels are significantly elevated during acute myocardial infarction (AMI) and play a key role in the cardiovascular system. A variety of methods have been established to detect myocardial infarction-related miRNAs. However, most require complex miRNA extraction and isolation, and these methods are virtually undetectable when RNA levels are low in the sample. It may lead to biased results. Thus, it is necessary to develop a technique that can detect miRNA without extracting it, which means that intracellular detection is of great significance. Here, we improved the traditional silicon spheres and obtained a biosensor that could effectively capture and detect specific noncoding nucleic acids through the layer-by-layer assembly method. The sensor is protected by hyaluronic acid so it can successfully escape the lysosome into the cell and achieve detection. With the help of a full-featured microplate reader, we determined that the detection limit of the biosensor could reach 1 fM, meeting the needs of intracellular detection. At the same time, we prepared an oxidative stress cardiomyocyte infarction model and successfully captured the overexpressed miR-124 in the infarcted cells to achieve in situ detection. This study could provide a new potential tool to develop miRNAs for sensitive diagnosis in AMI, and the proposed strategy implies its potential for biomedical research.

2D graphene-based advanced nanoarchitectonics for electrochemical biosensors: Applications in cancer biomarker detection

Low-cost, rapid, and easy-to-use biosensors for various cancer biomarkers are of utmost importance in detecting cancer biomarkers for early-stage metastasis control and efficient diagnosis. The molecular complexity of cancer biomarkers is overwhelming, thus, the repeatability and reproducibility of measurements by biosensors are critical factors. Electrochemical biosensors are attractive alternatives in cancer diagnosis due to their low cost, simple operation, and promising analytical figures of merit. Recently graphene-derived nanostructures have been used extensively for the fabrication of electrochemical biosensors because of their unique physicochemical properties, including the high electrical conductivity, adsorption capacity, low cost and ease of mass production, presence of oxygen-containing functional groups that facilitate the bioreceptor immobilization, increased flexibility and mechanical strength, low cellular toxicity. Indeed, these properties make them advantageous compared to other alternatives. However, some drawbacks must be overcome to extend their use, such as poor and uncontrollable deposition on the substrate due to the low dispersity of some graphene materials and irreproducibility of the results because of the differences in various batches of the produced graphene materials. This review has documented the most recently developed strategies for electrochemical sensor fabrication. It differs in the categorization method compared to published works to draw greater attention to the wide opportunities of graphene nanomaterials for biological applications. Limitations and future scopes are discussed to advance the integration of novel technologies such as artificial intelligence, the internet of medical things, and triboelectric nanogenerators to eventually increase efficacy and efficiency.

Multiplexed Capillary-Flow Driven Immunoassay for Respiratory Illnesses

Multiplexed analysis in medical diagnostics is widely accepted as a more thorough and complete method compared to single-analyte detection. While analytical methods like polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA) exist for multiplexed detection of biomarkers, they remain time-consuming and expensive. Lateral flow assays (LFAs) are an attractive option for point-of-care testing, and examples of multiplexed LFAs exist. However, these devices are limited by spatial resolution of test lines, large sample volume requirements, cross-reactivity, and poor sensitivity. Recent work has developed capillary-flow microfluidic ELISA platforms as a more sensitive alternative to LFAs; however, multiplexed detection on these types of devices has yet to be demonstrated. In the aftermath of the initial SARS-CoV-2 pandemic, the need for rapid, sensitive point-of-care devices has become ever clearer. Moving forward, devices that can distinguish between diseases with similar presenting symptoms would be the ideal home diagnostic. Here, the first example of a multiplexed capillary-flow immunoassay device for the simultaneous detection of multiple biomarkers is reported. From a single sample addition step, the reagents and washing steps required for two simultaneous ELISAs are delivered to spatially separated test strips. Visual results can be obtained in <15 min, and images captured with a smartphone can be analyzed for quantitative data. This device was used to distinguish between and quantify H1N1 hemagglutinin (HA) and SARS-CoV-2 nucleocapsid protein (N-protein). Using this device, analytical detection limits of 840 and 133 pg/mL were obtained for hemagglutinin and nucleocapsid protein, respectively. The presence of one target in the device did not increase the signal on the other test line, indicating no cross-reactivity between the assays. Additionally, simultaneous detection of both N-protein and HA was performed as well as simultaneous detection of N-protein and human C-reactive protein (CRP). Elevated levels of CRP in a patient infected with SARS-CoV-2 have been shown to correlate with more severe outcomes and a greater risk of death as well. To further expand on the simultaneous detection of two biomarkers, CRP and N-protein were detected simultaneously, and the presence of SARS-CoV-2 N-protein did not interfere with the detection of CRP when both targets were present in the sample.

Role of MicroRNA in Hypoxic Tumours and their Potential as Biomarkers for Early Detection of Cancer

Hypoxia is a pathophysiological condition characterized by oxygen deficiency in tissues, which negatively affects normal biological functions. It is a typical microenvironment character of almost all solid tumours. Noncoding RNA are small functional RNA molecules that regulate gene expression at chromatin and posttranscriptional levels. Micro-RNAs (miRNAs) are a type of noncoding RNA and are ~12-22 nucleotides long that are crucial in regulating gene expression by partnering with the mRNAs of protein-coding genes. It is widely reported that miRs play an important role in various key processes and pathways during tumour formation, as well as advancement in hypoxic tumors by influencing the HIF pathway. The role of miRNAs in hypoxic tumours, namely in pancreatic, kidney, breast, lung and colorectal, are described. These miRNAs have immense potential as diagnostic and prognostic biomarkers for early cancer detection.

MiR-4646-5p Acts as a Tumor-Suppressive Factor in Triple Negative Breast Cancer and Targets the Cholesterol Transport Protein GRAMD1B

MicroRNAs (miRNAs) are crucial post-transcriptional regulators of gene expression, and their deregulation contributes to many aspects of cancer development and progression. Thus, miRNAs provide insight into oncogenic mechanisms and represent promising targets for new therapeutic approaches. A type of cancer that is still in urgent need of improved treatment options is triple negative breast cancer (TNBC). Therefore, we aimed to characterize a novel miRNA with a potential role in TNBC. Based on a previous study, we selected miR-4646-5p, a miRNA with a still unknown function in breast cancer. We discovered that higher expression of miR-4646-5p in TNBC patients is associated with better survival. In vitro assays showed that miR-4646-5p overexpression reduces growth, proliferation, and migration of TNBC cell lines, whereas inhibition had the opposite effect. Furthermore, we found that miR-4646-5p inhibits the tube formation ability of endothelial cells, which may indicate anti-angiogenic properties. By whole transcriptome analysis, we not only observed that miR-4646-5p downregulates many oncogenic factors, like tumor-promoting cytokines and migration- and invasion-related genes, but were also able to identify a direct target, the GRAM domain-containing protein 1B (GRAMD1B). GRAMD1B is involved in cellular cholesterol transport and its knockdown phenocopied the growth-reducing effects of miR-4646-5p. We thus conclude that GRAMD1B may partly contribute to the diverse tumor-suppressive effects of miR-4646-5p in TNBC.

Application of microfluidic technology based on surface-enhanced Raman scattering in cancer biomarker detection: A review

With the continuous discovery and research of predictive cancer-related biomarkers, liquid biopsy shows great potential in cancer diagnosis. Surface-enhanced Raman scattering (SERS) and microfluidic technology have received much attention among the various cancer biomarker detection methods. The former has ultrahigh detection sensitivity and can provide a unique fingerprint. In contrast, the latter has the characteristics of miniaturization and integration, which can realize accurate control of the detection samples and high-throughput detection through design. Both have the potential for point-of-care testing (POCT), and their combination (lab-on-a-chip SERS (LoC-SERS)) shows good compatibility. In this paper, the basic situation of circulating proteins, circulating tumor cells, exosomes, circulating tumor DNA (ctDNA), and microRNA (miRNA) in the diagnosis of various cancers is reviewed, and the detection research of these biomarkers by the LoC-SERS platform in recent years is described in detail. At the same time, the challenges and future development of the platform are discussed at the end of the review. Summarizing the current technology is expected to provide a reference for scholars engaged in related work and interested in this field.

Circ_PRDM5/miR-25-3p/ANKRD46 axis is associated with cell malignant behaviors in subjects with breast cancer evaluated by ultrasound

Circular RNAs (circRNAs) are key RNA molecules in cancer biology. CircRNA PR/SET domain 5 (circ_PRDM5, hsa_circ_0005654) was downregulated in breast cancer (BC) tissues. This study is designed to investigate the functional mechanism of circ_PRDM5 in BC. Ultrasound examinations were performed to evaluate BC patients and normal individuals. Circ_PRDM5, miR-25-3p, and Ankyrin repeat domain 46 (ANKRD46) level detection was carried out by reverse transcription-quantitative polymerase chain reaction. 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) assay was used for cell viability examination. Cell proliferation was evaluated by ethynyl-2'-deoxyuridine assay and colony formation assay. The protein levels were examined using western blot. Cell migration and invasion abilities were assessed via transwell assay. Target interaction was analyzed via dual-luciferase reporter assay. The role of circ_PRDM5 in vivo was explored via xenograft tumor assay. Circ_PRDM5 expression was downregulated in BC tissues and cells. Overexpression of circ_PRDM5 suppressed proliferation and motility but enhanced apoptosis of BC cells. Circ_PRDM5 served as a sponge of miR-25-3p. Circ_PRDM5 impeded BC cell malignant development via sponging miR-25-3p. Circ_PRDM5 induced ANKRD46 upregulation by targeting miR-25-3p. Inhibition of miR-25-3p retarded BC progression by increasing the ANKRD46 level. Circ_PRDM5 repressed BC tumorigenesis in vivo through mediating the miR-25-3p/ANKRD46 axis. This study evidenced that circ_PRDM5 inhibited cell progression and tumor growth in BC via interacting with mir-25-3p/ANKRD46 network.

In Vitro microRNA Expression Profile Alterations under CDK4/6 Therapy in Breast Cancer

BACKGROUND

Breast cancer is the most common type of cancer worldwide. Cyclin-dependent kinase inhibition is one of the backbones of metastatic breast cancer therapy. However, there are a significant number of therapy failures. This study evaluates the biomarker potential of microRNAs for the prediction of a therapy response under cyclin-dependent kinase inhibition.

METHODS

This study comprises the analysis of intracellular and extracellular microRNA-expression-level alterations of 56 microRNAs under palbociclib mono as well as combination therapy with letrozole. Breast cancer cell lines BT-474, MCF-7 and HS-578T were analyzed using qPCR.

RESULTS

A palbociclib-induced microRNA signature could be detected intracellularly as well as extracellularly. Intracellular miR-10a, miR-15b, miR-21, miR-23a and miR-23c were constantly regulated in all three cell lines, whereas let-7b, let-7d, miR-15a, miR-17, miR-18a, miR-20a, miR-191 and miR301a_3p were regulated only in hormone-receptor-positive cells. Extracellular miR-100, miR-10b and miR-182 were constantly regulated across all cell lines, whereas miR-17 was regulated only in hormone-receptor-positive cells.

CONCLUSIONS

Because they are secreted and significantly upregulated in the microenvironment of tumor cells, miRs-100, -10b and -182 are promising circulating biomarkers that can be used to predict or detect therapy responses under CDK inhibition. MiR-10a, miR-15b, miR-21, miR-23a and miR-23c are potential tissue-based biomarkers.

microRNA Detection via Nanostructured Biochips for Early Cancer Diagnostics

MicroRNA (miRNA) are constituted of approximately 22 nucleotides and play an important role in the regulation of many physiological functions and diseases. In the last 10 years, an increasing interest has been recorded in studying the expression profile of miRNAs in cancer. Real time-quantitative polymerase chain reaction (RT-qPCR), microarrays, and small RNA sequencing represent the gold standard techniques used in the last 30 years as detection methods. The advent of nanotechnology has allowed the fabrication of nanostructured biosensors which are widely exploited in the diagnostic field. Nanostructured biosensors offer many advantages: (i) their small size allows the construction of portable, wearable, and low-cost products; (ii) the large surface-volume ratio enables the loading of a great number of biorecognition elements (e.g., probes, receptors); and (iii) direct contact of the recognition element with the analyte increases the sensitivity and specificity inducing low limits of detection (LOD). In this review, the role of nanostructured biosensors in miRNA detection is explored, focusing on electrochemical and optical sensing. In particular, four types of nanomaterials (metallic nanoparticles, graphene oxide, quantum dots, and nanostructured polymers) are reported for both detection strategies with the aim to show their distinct properties and applications.

In Silico Analysis of Publicly Available Transcriptomic Data for the Identification of Triple-Negative Breast Cancer-Specific Biomarkers

BACKGROUND

Breast cancer is the most common type of cancer among women and is classified into multiple subtypes. Triple-negative breast cancer (TNBC) is the most aggressive subtype, with high mortality rates and limited treatment options such as chemotherapy and radiation. Due to the heterogeneity and complexity of TNBC, there is a lack of reliable biomarkers that can be used to aid in the early diagnosis and prognosis of TNBC in a non-invasive screening method.

AIM

This study aims to use in silico methods to identify potential biomarkers for TNBC screening and diagnosis, as well as potential therapeutic markers.

METHODS

Publicly available transcriptomic data of breast cancer patients published in the NCBI's GEO database were used in this analysis. Data were analyzed with the online tool GEO2R to identify differentially expressed genes (DEGs). Genes that were differentially expressed in more than 50% of the datasets were selected for further analysis. Metascape, Kaplan-Meier plotter, cBioPortal, and the online tool TIMER were used for functional pathway analysis to identify the biological role and functional pathways associated with these genes. Breast Cancer Gene-Expression Miner v4.7 was used to validify the obtained results in a larger cohort of datasets.

RESULTS

A total of 34 genes were identified as differentially expressed in more than half of the datasets. The DEG GATA3 had the highest degree of regulation, and it plays a role in regulating other genes. The estrogen-dependent pathway was the most enriched pathway, involving four crucial genes, including GATA3. The gene FOXA1 was consistently down-regulated in TNBC in all datasets.

CONCLUSIONS

The shortlisted 34 DEGs will aid clinicians in diagnosing TNBC more accurately as well as developing targeted therapies to improve patient prognosis. In vitro and in vivo studies are further recommended to validate the results of the current study.

Coding roles of long non-coding RNAs in breast cancer: Emerging molecular diagnostic biomarkers and potential therapeutic targets with special reference to chemotherapy resistance

Dysregulation of epigenetic mechanisms have been depicted in several pathological consequence such as cancer. Different modes of epigenetic regulation (DNA methylation (hypomethylation or hypermethylation of promotor), histone modifications, abnormal expression of microRNAs (miRNAs), long non-coding RNAs, and small nucleolar RNAs), are discovered. Particularly, lncRNAs are known to exert pivot roles in different types of cancer including breast cancer. LncRNAs with oncogenic and tumour suppressive potential are reported. Differentially expressed lncRNAs contribute a remarkable role in the development of primary and acquired resistance for radiotherapy, endocrine therapy, immunotherapy, and targeted therapy. A wide range of molecular subtype specific lncRNAs have been assessed in breast cancer research. A number of studies have also shown that lncRNAs may be clinically used as non-invasive diagnostic biomarkers for early detection of breast cancer. Such molecular biomarkers have also been found in cancer stem cells of breast tumours. The objectives of the present review are to summarize the important roles of oncogenic and tumour suppressive lncRNAs for the early diagnosis of breast cancer, metastatic potential, and chemotherapy resistance across the molecular subtypes.

A 5-Pathway Signature Predicts Prognosis Based on Immune-Derived lncRNAs in Patients with Breast Cancer

Background

Currently, predictive models were not developed based on the signaling pathway signatures of immune-related lncRNAs in breast cancer (BRCA) patients.

Methods

We selected unsupervised hierarchical clustering algorithm to classify patients with BRCA based on the significant immune-derived lncRNAs from the TCGA dataset. And different methods including ESTIMATE, ImmuneCellAI, and CIBERSORT were performed to evaluate the immune infiltration of tumor microenvironment. Using Lasso regression algorithm, we filtered the significant signaling pathways enriched by GSEA, GSVA, or PPI analysis to develop a prognostic model. And a nomogram integrated with clinical factors and significant pathways was constructed to predict the precise probability of overall survival (OS) of BRCA patients in the TCGA dataset (n = 1,098) and another two testing sets (n = 415).

Results

BRCA patients were stratified into the PC (n = 571) and GC (n = 527) subgroup with significantly different prognosis with 550 immune-related lncRNAs in the TCGA dataset. Integrated analysis revealed different immune response, oncogenic signaling, and metabolic reprograming pathways between these two subgroups. And a 5-pathway signature could predict the prognosis of BRCA patients between these two subgroups independently in the TCGA dataset, which was confirmed in another two cohorts from the GEO dataset. In the TCGA dataset, 5-year OS rate was 78% (95% CI: 73-84) vs. 82% (95% CI: 77-87) for the PC and GC group (HR = 1.63 (95% CI: 1.17-2.28), p = 0.004). The predictive power was similar in another two testing sets (HR > 1.20, p  <  0.01). Finally, a nomogram is developed for clinical application, which integrated this signature and age to accurately predict the survival probability in BRCA patients.

Conclusion

This 5-pathway signature correlated with immune-derived lncRNAs was able to precisely predict the prognosis for patients with BRCA and provided a rich source characterizing immune-related lncRNAs and further informed strategies to target BRCA vulnerabilities.

Medical Internet-of-Things Based Breast Cancer Diagnosis Using Hyperparameter-Optimized Neural Networks

In today’s healthcare setting, the accurate and timely diagnosis of breast cancer is critical for recovery and treatment in the early stages. In recent years, the Internet of Things (IoT) has experienced a transformation that allows the analysis of real-time and historical data using artificial intelligence (AI) and machine learning (ML) approaches. Medical IoT combines medical devices and AI applications with healthcare infrastructure to support medical diagnostics. The current state-of-the-art approach fails to diagnose breast cancer in its initial period, resulting in the death of most women. As a result, medical professionals and researchers are faced with a tremendous problem in early breast cancer detection. We propose a medical IoT-based diagnostic system that competently identifies malignant and benign people in an IoT environment to resolve the difficulty of identifying early-stage breast cancer. The artificial neural network (ANN) and convolutional neural network (CNN) with hyperparameter optimization are used for malignant vs. benign classification, while the Support Vector Machine (SVM) and Multilayer Perceptron (MLP) were utilized as baseline classifiers for comparison. Hyperparameters are important for machine learning algorithms since they directly control the behaviors of training algorithms and have a significant effect on the performance of machine learning models. We employ a particle swarm optimization (PSO) feature selection approach to select more satisfactory features from the breast cancer dataset to enhance the classification performance using MLP and SVM, while grid-based search was used to find the best combination of the hyperparameters of the CNN and ANN models. The Wisconsin Diagnostic Breast Cancer (WDBC) dataset was used to test the proposed approach. The proposed model got a classification accuracy of 98.5% using CNN, and 99.2% using ANN.

Single-Molecule Sensor for High-Confidence Detection of miRNA

MicroRNAs (miRNAs) play a crucial role in regulating gene expression and have been linked to many diseases. Therefore, sensitive and accurate detection of disease-linked miRNAs is vital to the emerging revolution in early diagnosis of diseases. While the detection of miRNAs is a challenge due to their intrinsic properties such as small size, high sequence similarity among miRNAs and low abundance in biological fluids, the majority of miRNA-detection strategies involve either target/signal amplification or involve complex sensing designs. In this study, we have developed and tested a DNA-based fluorescence resonance energy transfer (FRET) sensor that enables ultrasensitive detection of a miRNA biomarker (miRNA-342-3p) expressed by triple-negative breast cancer (TNBC) cells. The sensor shows a relatively low FRET state in the absence of a target but it undergoes continuous FRET transitions between low- and high-FRET states in the presence of the target. The sensor is highly specific, has a detection limit down to low femtomolar (fM) without having to amplify the target, and has a large dynamic range (3 orders of magnitude) extending to 300 000 fM. Using this strategy, we demonstrated that the sensor allows detection of miRNA-342-3p in the miRNA-extracts from cancer cell lines and TNBC patient-derived xenografts. Given the simple-to-design hybridization-based detection, the sensing platform developed here can be used to detect a wide range of miRNAs enabling early diagnosis and screening of other genetic disorders.

miR-888 and E-Cadherin Levels in Ductal Carcinoma Breast Cancer as Possible Cancer-Related Markers

Background: Cancer occurs due to genetic or epigenetic factors. Breast cancer (BC) is the most common cancer among females and is considered one of the leading causes of cancer death worldwide. Epigenetic biomarkers have proven to be important in cancer management. Methods: E-cadherin gene expression and its associated regulatory microRNA, miR-888, were studied in 60 ductal carcinoma BC patients compared with normal controls using real-time Reverse Transcription Polymerase Chain Reaction. In addition, the association of the gene and microRNA expression with hormone receptors and other clinicopathologic characteristics were assessed. The correlation between plasma and tumor miR-888 expression was studied to evaluate its potential as a marker of noninvasiveness. Results: The results showed a significant increase in expression of miR-888, and a decrease in E-cadherin expression in tumor tissues compared with normal controls. The miR-888 and E-cadherin mRNA levels showed an inverse correlation. The overexpression of miR-888 in both tumor and plasma and downregulation of E-cadherin were particularly prominent when there was nodal involvement and distant metastasis status as we well as being significantly associated with higher disease stages and triple-negative tumor hormone receptor status. The Kaplan-Meier survival curves indicated that overall survival was significantly poor in BC patients with higher miR-888 and lower E-cadherin expression. Conclusions: Our study indicated that elevated eXpression of miR-888 may be a negative prognostic factor in breast cancer.

miRNAs in Cancer (Review of Literature)

MicroRNAs (miRNAs) are short, noncoding, single-stranded RNA molecules that regulate gene expression at the post-transcriptional level by binding to mRNAs. miRNAs affect the course of processes of fundamental importance for the proper functioning of the organism. These processes include cell division, proliferation, differentiation, cell apoptosis and the formation of blood vessels. Altered expression of individual miRNAs has been shown in numerous cancers, which may indicate the oncogenic or suppressor potential of the molecules in question. This paper discusses the current knowledge about the possibility of using miRNA as a diagnostic marker and a potential target in modern anticancer therapies.

Small non-coding RNA profiling in breast cancer: plasma U6 snRNA, miR-451a and miR-548b-5p as novel diagnostic and prognostic biomarkers

BACKGROUND

Breast cancer is a leading cause of cancer-related death in women. Most cases are invasive ductal carcinomas of no special type (NST breast carcinomas).

METHODS AND RESULTS

In this prospective, multicentric biomarker discovery study, we analyzed the expression of small non-coding RNAs (mainly microRNAs) in plasma by qPCR and evaluated their association with NST breast cancer. Large-scale expression profiling and subsequent validations have been performed in patient and control groups and compared with clinicopathological data. Small nuclear U6 snRNA, miR-548b-5p and miR-451a have been identified as candidate biomarkers. U6 snRNA was remarkably overexpressed in all the validations, miR-548b-5p levels were generally elevated and miR-451a expression was mostly downregulated in breast cancer groups. Combined U6 snRNA/miR-548b-5p signature demonstrated the best diagnostic performance based on the ROC curve analysis with AUC of 0.813, sensitivity 73.1% and specificity 82.6%. There was a trend towards increased expression of both miR-548b-5p and U6 snRNA in more advanced stages. Further, increased miR-548b-5p levels have been partially associated with higher grades, multifocality, Ki-67 positivity, and luminal B rather than luminal A samples. On the other hand, an association has been observed between high miR-451a expression and progesterone receptor positivity, lower grade, unifocal samples, Ki-67-negativity, luminal A rather than luminal B samples as well as improved progression-free survival and overall survival.

CONCLUSIONS

Our results indicated that U6 snRNA and miR-548b-5p may have pro-oncogenic functions, while miR-451a may act as tumor suppressor in breast cancer.

MiR-126-5p Promotes Tumor Cell Proliferation, Metastasis and Invasion by Targeting TDO2 in Hepatocellular Carcinoma

TDO2 is a key enzyme in the kynurenine metabolic pathway, which is the most important pathway of tryptophan metabolism. It has been shown that miRNAs are involved in cell metastasis through interaction with target mRNAs. In this study, we found 645 miRNAs that could be immunoprecipitated with TDO2 through the RNA-immunoprecipitation experiment. miR-126-5p was selected as the research target, which was also confirmed by dual-luciferase reporter assay. Through qRT-PCR analysis, it was verified that the overexpression of miR-126-5p promoted the expression of TDO2, PI3K/AKT and WNT1. Meanwhile, it was verified that overexpression of miR-126-5p can promote intracellular tryptophan metabolism by HPLC. We also verified the effects of miR-126-5p on cell proliferation, migration, and invasion by cck-8, cell colony formation and trans-well assay in both HCCLM3 cells and HepG2 cells. In vivo experiments were also conducted to verify that miR-126-5p promoted tumor formation and growth via immunohistochemical detection of cell infiltration and proliferation to generate markers Ki-67, BAX, and VEGF. In conclusion, our results suggest that miR-126-5p is a biomarker and a potential new treatment target in the progression of HCC via promoting the expression of TDO2.

Regulation of the Effect of Physical Activity Through MicroRNAs in Breast Cancer

Physical activity and exercise can induce beneficial molecular and biological regulations that have been associated with an incidence of various diseases, including breast cancer. Recent studies demonstrated that the potential links between physical activity-induced circulating microRNAs (miRNAs) and cancer risk and progression. Here, we investigated whether altered miRNAs by exercise could influence breast cancer progression. After primary searching in PubMed and reviewing the full-text papers, candidate miRNAs altered by exercise in breast cancer were identified. Analysis of expression profiles and clinical outcomes of altered miRNAs using The Cancer Genome Atlas datasets showed altered miRNAs expressions were significantly associated with the patient's prognosis, whereas prognostic values of each miRNA varied in different stages and subtypes. In addition, altered miRNAs profiles regulated various target genes and key signaling pathways in tumorigenesis, including pathways in cancer and the PI3K-Akt signaling pathway; however, miRNAs regulated the expression of target genes differently according to tumor stages and subtypes. These results indicate that circulating miRNAs are promising noninvasive stable biomarkers for early detection, diagnosis, prognosis, and monitoring the response to clinical therapies of breast cancer. Moreover, stages and subtype-stratified approaches for breast cancer progression would be needed to evaluate the prognostic value of miRNAs for biomarkers and therapeutic targets.

MicroRNA Cues from Nature: A Roadmap to Decipher and Combat Challenges in Human Health and Disease?

MicroRNAs are small non-coding RNA (18–24 nt long) that fine-tune gene expression at the post-transcriptional level. With the advent of “multi-omics” analysis and sequencing approaches, they have now been implicated in every facet of basic molecular networks, including metabolism, homeostasis, and cell survival to aid cellular machinery in adapting to changing environmental cues. Many animals must endure harsh environmental conditions in nature, including cold/freezing temperatures, oxygen limitation (anoxia/hypoxia), and food or water scarcity, often requiring them to revamp their metabolic organization, frequently on a seasonal or life stage basis. MicroRNAs are important regulatory molecules in such processes, just as they are now well-known to be involved in many human responses to stress or disease. The present review outlines the role of miRNAs in natural animal models of environmental stress and adaptation including torpor/hibernation, anoxia/hypoxia tolerance, and freeze tolerance. We also discuss putative medical applications of advances in miRNA biology including organ preservation for transplant, inflammation, ageing, metabolic disorders (e.g., obesity), mitochondrial dysfunction (mitoMirs) as well as specialized miRNA subgroups respective to low temperature (CryomiRs) and low oxygen (OxymiRs). The review also covers differential regulation of conserved and novel miRNAs involved at cell, tissue, and stress specific levels across multiple species and their roles in survival. Ultimately, the species-specific comparison and conserved miRNA responses seen in evolutionarily disparate animal species can help us to understand the complex miRNA network involved in regulating and reorganizing metabolism to achieve diverse outcomes, not just in nature, but in human health and disease.

Carbon Nanotube Field-Effect Transistor Biosensor for Ultrasensitive and Label-Free Detection of Breast Cancer Exosomal miRNA21

Tumor-derived exosomal miRNAs may have important functions in the onset and progression of cancers and are potential biomarkers for early diagnosis and prognosis monitoring. Yet, simple, sensitive, and label-free detection of exosomal miRNAs remains challenging. Herein, an ultrasensitive, label-free, and stable field-effect transistor (FET) biosensor based on a polymer-sorted high-purity semiconducting carbon nanotube (CNT) film is reported to detect exosomal miRNA. Different from conventional CNT FETs, the CNT FET biosensors employed a floating gate structure using an ultrathin Y₂O₃ as an insulating layer, and assembled Au nanoparticles (AuNPs) on Y₂O₃ as linkers to anchor probe molecules. A thiolated oligonucleotide probe was immobilized on the AuNP surface of the sensing area, after which miRNA21 was detectable by monitoring the current change before and after hybridization between the immobilized DNA probe and target miRNA. This method achieved both high sensitivity (LOD: 0.87 aM) and high specificity. Furthermore, the FET biosensor was employed to test clinical plasma samples, showing significant differences between healthy people and breast cancer patients. The CNT FET biosensor shows the potential applications in the clinical diagnosis of breast cancer.

Nanomaterial-Based Fluorescence Resonance Energy Transfer (FRET) and Metal-Enhanced Fluorescence (MEF) to Detect Nucleic Acid in Cancer Diagnosis

Nucleic acids, including DNA and RNA, have received prodigious attention as potential biomarkers for precise and early diagnosis of cancers. However, due to their small quantity and instability in body fluids, precise and sensitive detection is highly important. Taking advantage of the ease-to-functionality and plasmonic effect of nanomaterials, fluorescence resonance energy transfer (FRET) and metal-enhanced fluorescence (MEF)-based biosensors have been developed for accurate and sensitive quantitation of cancer-related nucleic acids. This review summarizes the recent strategies and advances in recently developed nanomaterial-based FRET and MEF for biosensors for the detection of nucleic acids in cancer diagnosis. Challenges and opportunities in this field are also discussed. We anticipate that the FRET and MEF-based biosensors discussed in this review will provide valuable information for the sensitive detection of nucleic acids and early diagnosis of cancers.

Oncogenic and Tumor Suppressive Components of the Cell Cycle in Breast Cancer Progression and Prognosis

Cancer, a disease of inappropriate cell proliferation, is strongly interconnected with the cell cycle. All cancers consist of an abnormal accumulation of neoplastic cells, which are propagated toward uncontrolled cell division and proliferation in response to mitogenic signals. Mitogenic stimuli include genetic and epigenetic changes in cell cycle regulatory genes and other genes which regulate the cell cycle. This suggests that multiple, distinct pathways of genetic alterations lead to cancer development. Products of both oncogenes (including cyclin-dependent kinase (CDKs) and cyclins) and tumor suppressor genes (including cyclin-dependent kinase inhibitors) regulate cell cycle machinery and promote or suppress cell cycle progression, respectively. The identification of cyclins and CDKs help to explain and understand the molecular mechanisms of cell cycle machinery. During breast cancer tumorigenesis, cyclins A, B, C, D1, and E; cyclin-dependent kinase (CDKs); and CDK-inhibitor proteins p16, p21, p27, and p53 are known to play significant roles in cell cycle control and are tightly regulated in normal breast epithelial cells. Following mitogenic stimuli, these components are deregulated, which promotes neoplastic transformation of breast epithelial cells. Multiple studies implicate the roles of both types of components-oncogenic CDKs and cyclins, along with tumor-suppressing cyclin-dependent inhibitors-in breast cancer initiation and progression. Numerous clinical studies have confirmed that there is a prognostic significance for screening for these described components, regarding patient outcomes and their responses to therapy. The aim of this review article is to summarize the roles of oncogenic and tumor-suppressive components of the cell cycle in breast cancer progression and prognosis.

Intrinsic and extrinsic pathways of apoptosis: Role in cancer development and prognosis

Apoptosis, also named programmed cell death, is a fundament process required for morphogenetic homeostasis during early development and in pathophysiological conditions. It is come into existence in 1972 by work of Kerr, Wyllie and Currie and later on investigated during the research on development of the C. elegans. Trigger by several stimuli, apoptosis is necessary during the embryonic development and aging as homeostatic mechanism to control the cell population and also play a key role as defense mechanism against the immune responses and elimination of damaged cells. Cancer, a genetic disease, is a growing burden on the health and economy of both developing and developed countries. Every year there is tremendously increasing in the number of new cancer cases and mortality rate. Although, there is a significant improvement have been made in biotechnological and bioinformatic fields however, the therapeutic advantages and cancer etiology is still under explored. Several studies determined the deregulation of different apoptotic components during the cancer development and progression. Apoptosis relies on activation of distinct signaling pathways that are often deregulated in cancer. Thus, exploring the single or more than one apoptotic component underlying their expression in carcinogenesis could help to track the disease progression. Current book chapter will provide the several evidences supporting the use of different apoptotic components as prognosis and prediction markers in various human cancer types.

Nanoporous Anodic Alumina-Based Sensor for miR-99a-5p Detection as an Effective Early Breast Cancer Diagnostic Tool

Circulating microRNAs have emerged as potential diagnostic biomarkers. The deregulation of the microRNA miR-99a-5p has been previously described as an effective biomarker of early breast cancer. Herein, we present a new nanoporous anodic alumina (NAA)-based biosensor that can detect plasma miR-99a-5p with high sensitivity and selectivity. NAA pores are loaded with rhodamine B and capped with a specific oligonucleotide that is able to block cargo release until the target is present. In the presence of miR-99a-5p, the capping oligonucleotide recognizes the miR-99a-5p sequence and displaces it allowing the release of the encapsulated dye. This method is able to successfully distinguish healthy controls from breast cancer patients, even at early stages with high efficiency, showing the presented system as a promising tool for breast cancer detection.

Determination of FABP4, RBP4 and the MMP-9/NGAL complex in the serum of women with breast cancer

Breast cancer is the most common type of cancer in females and is the leading cause of cancer-associated death among women, worldwide. The present study aimed to measure the serum levels of fatty acid-binding protein 4 (FABP4), retinol binding protein 4 (RBP4) and the MMP-9/neutrophil gelatinase-associated lipocalin (NGAL) complex in women diagnosed with breast cancer. Serum levels of the examined proteins were determined in the peripheral blood of patients via ELISA. Furthermore, whether the concentration of each protein was associated with breast cancer growth, molecular subtype, BMI, postmenopausal status, diabetes and the social background of patients was assessed. Women with invasive breast cancer demonstrated significantly higher levels of FABP4 (P=0.008). Additionally, considerably elevated FABP4 levels were demonstrated specifically in Luminal breast cancer cases (P<0.01). No significant association was recorded between RBP4 and breast cancer development. In addition, significantly lower levels of the MMP-9/NGAL complex were recorded in triple negative/HER-2 cases (P<0.05). BMI values appeared to influence the aforementioned associations, while significantly high serum levels of FABP4 and the MMP-9/NGAL complex were found in postmenopausal patients with breast cancer and a BMI ≥25 kg/m² (P<0.05). In addition, high levels of FABP4 were significantly associated with breast cancer patients with diabetes (P=0.05). However, no association was identified between RBP4, the MMP-9/NGAL complex and diabetes. In conclusion, FABP4 can be regarded as a biomarker of breast cancer growth, while both FABP4 and the MMP-9/NGAL complex may provide considerable information regarding the development of specific breast cancer subtypes. FABP4 and the MMP-9/NGAL complex may also be able to predict the development of breast cancer in postmenopausal patients with obesity.

Circulating miR-99a-5p Expression in Plasma: A Potential Biomarker for Early Diagnosis of Breast Cancer

MicroRNAs have emerged as new diagnostic and therapeutic biomarkers for breast cancer. Herein, we analysed miR-99a-5p expression levels in primary tumours and plasma of breast cancer patients to evaluate its usefulness as a minimally invasive diagnostic biomarker. MiR-99a-5p expression levels were determined by quantitative real-time PCR in three independent cohorts of patients: (I) Discovery cohort: breast cancer tissues (n = 103) and healthy breast tissues (n = 26); (II) Testing cohort: plasma samples from 105 patients and 98 healthy donors; (III) Validation cohort: plasma samples from 89 patients and 85 healthy donors. Our results demonstrated that miR-99a-5p was significantly downregulated in breast cancer tissues compared to healthy breast tissues. Conversely, miR-99a-5p levels were significantly higher in breast cancer patients than in healthy controls in plasma samples from both testing and validation cohorts, and ROC curve analysis revealed that miR-99a-5p has good diagnostic potential even to detect early breast cancer. In conclusion, miR-99a-5p’s deregulated expression distinguished healthy patients from breast cancer patients in two different types of samples (tissues and plasma). Interestingly, expression levels in plasma were significantly lower in healthy controls than in early-stage breast cancer patients. Our findings suggest circulating miR-99a-5p as a novel promising non-invasive biomarker for breast cancer detection.

A review of clinical and emerging biomarkers for breast cancers: towards precision medicine for patients

Background:

Breast cancer is the most commonly diagnosed malignancy among women and accounts for about 25% of all new cancer cases and 13% of all cancer deaths in Canadian women. It is a highly heterogeneous disease, encompassing multiple tumour entities, each characterised by distinct morphology, behaviour and clinical implications. Moreover, different breast tumour subtypes have different risk factors, clinical presentation, histopathological features, outcome and response to systemic therapies. Therefore, any strategies capable of the stratification of breast cancer by clinically relevant subtypes are an important requirement for personalised and targeted treatment. Therefore, in the advancement towards the concept of precision medicine that takes individual patient variability into account, several investigators have focused on the identification of effective clinical breast cancer biomarkers that interrogate key aberrant pathways potentially targetable with molecular targeted or immunological therapies.

Methods and materials:

This paper reports on a review of 11 current clinical and emerging biomarkers used in screening for early detection and diagnosis, to stratify patients by disease subtype, to identify patients’ risk for metastatic disease and subsequent relapse, to monitor patient response to specific treatment and to provide clinicians the possibility of prospectively identifying groups of patients who will benefit from a particular treatment.

Conclusion:

The future holds promising for the use of effective clinical breast cancer biomarkers for early detection and personalised patient-specific targeted treatment and increased patient survival. Breast cancer biomarkers can potentially assist in early-staged, non-invasive, sensitive and specific breast cancer detection and screening, provide clinically useful information for identification of patients with a greater likelihood of benefiting from the specific treatment, offer a better understanding of the metastatic process in cancer patients, predict disease and for patients with the established disease can assist define the nature of the disease, monitor the success of treatment and guide the clinical management of the disease.

Circulating MicroRNAs as Prognostic and Therapeutic Biomarkers in Breast Cancer Molecular Subtypes

Breast cancer (BC) is a common and heterogeneous disease, of which six molecular subtypes, characterized by different biological features and clinical outcomes, were described. The identification of additional biomarkers able to further connote and distinguish the different BC subtypes is essential to improve the diagnostic, prognostic and therapeutic strategies in BC patients. MicroRNAs (miRNAs) are short non-coding RNA involved in several physiological and pathological processes, including cancer development and progression. In particular, circulating miRNAs, which can be found in an adequately stable structure in serum/plasma of cancer patients, are emerging as very promising non-invasive biomarkers. Several studies have analyzed the potential role of circulating miRNAs as prognostic and therapeutic markers in BC. In the present review we describe circulating miRNAs, identified as putative biomarker in BC, with special reference to different BC molecular subtypes.

Bone marrow stromal cells-derived exosomes target DAB2IP to induce microglial cell autophagy, a new strategy for neural stem cell transplantation in brain injury

Bone marrow stromal cells (MSCs) are a useful source of stem cells for the treatment of various brain injury diseases due to their abundant supply and fewer ethical problems compared with transplant treatment. However, the clinical application of MSCs is limited due to allograft rejection and immunosuppression in the process of MSCs transplantation. According to previous studies, microglial cell autophagy occurs following co-culture with MSCs. In the present study, exosomes were obtained from MSCs and subsequently characterized using transmission electron microscopy, atomic force microscopy and dynamic light scattering particle size analysis. The type of microRNAs (miRs) found in the exosomes was then analyzed via gene chip. The results demonstrated that microglial cell autophagy could be induced by exosomes. This mechanism was therefore investigated further via reverse transcription-quantitative PCR, western blotting and luciferase assays. These results demonstrated that exosomes from MSCs could induce microglial cell autophagy through the miR-32-mediated regulation of disabled homolog 2-interacting protein, thus providing a theoretical basis for the clinical application of miRs in MSCs.

High expression of miR-135b predicts malignant transformation and poor prognosis of gastric cancer

AIMS

MiR-135b is a downstream effector of oncogenic signaling pathways. This study aimed to reveal the underlying regulation and significance of miR-135b in gastric cancer.

MATERIALS AND METHODS

The influence of Wnt and PI3K/AKT signaling pathways on the transcriptional activation of the miR-135b promoter was determined by dual-luciferase reporter assays. In vitro experiments, including the cell counting kit-8 (CCK8) assay, 5-ethynyl-2'-deoxyuridine (EdU) staining, flow cytometry analysis and malignant phenotype profiles, were conducted to determine the oncogenic role of miR-135b in gastric cancer. To analyze the clinical significance of miR-135b in gastric cancer, the expression profile of miR-135b in tissue specimens and plasma was examined by quantitative real-time PCR (qRT-PCR).

KEY FINDINGS

Oncogenic signaling pathways represented by Wnt and PI3K/AKT promoted the transcriptional activation of the miR-135b promoter in gastric cancer. Downregulation of miR-135b inhibited proliferation, promoted apoptosis, and suppressed the migratory, invasive, and adherent abilities as well as the cancer stem cell phenotype of gastric cancer cells. High expression of miR-135b in gastric cancer tissues was tightly associated with poor prognosis and malignant transformation represented by metastasis of gastric cancer. The miR-135b level in the plasma of gastric cancer patients was significantly higher than that in healthy individuals.

SIGNIFICANCE

MiR-135b is a potential downstream effector of the Wnt and PI3K/AKT signaling pathways in gastric cancer. High expression of miR-135b may predict malignant transformation and poor prognosis of gastric cancer. This study reveals the potential role of miR-135b as a target for the early diagnosis and therapy of gastric cancer.

Electrochemical Nanobiosensors for Detection of Breast Cancer Biomarkers

This comprehensive review paper describes recent advances made in the field of electrochemical nanobiosensors for the detection of breast cancer (BC) biomarkers such as specific genes, microRNA, proteins, circulating tumor cells, BC cell lines, and exosomes or exosome-derived biomarkers. Besides the description of key functional characteristics of electrochemical nanobiosensors, the reader can find basic statistic information about BC incidence and mortality, breast pathology, and current clinically used BC biomarkers. The final part of the review is focused on challenges that need to be addressed in order to apply electrochemical nanobiosensors in a clinical practice.

Cardiac dysfunction in cancer patients: beyond direct cardiomyocyte damage of anticancer drugs: novel cardio-oncology insights from the joint 2019 meeting of the ESC Working Groups of Myocardial Function and Cellular Biology of the Heart

In western countries, cardiovascular (CV) disease and cancer are the leading causes of death in the ageing population. Recent epidemiological data suggest that cancer is more frequent in patients with prevalent or incident CV disease, in particular, heart failure (HF). Indeed, there is a tight link in terms of shared risk factors and mechanisms between HF and cancer. HF induced by anticancer therapies has been extensively studied, primarily focusing on the toxic effects that anti-tumour treatments exert on cardiomyocytes. In this Cardio-Oncology update, members of the ESC Working Groups of Myocardial Function and Cellular Biology of the Heart discuss novel evidence interconnecting cardiac dysfunction and cancer via pathways in which cardiomyocytes may be involved but are not central. In particular, the multiple roles of cardiac stromal cells (endothelial cells and fibroblasts) and inflammatory cells are highlighted. Also, the gut microbiota is depicted as a new player at the crossroads between HF and cancer. Finally, the role of non-coding RNAs in Cardio-Oncology is also addressed. All these insights are expected to fuel additional research efforts in the field of Cardio-Oncology.

Diagnostic Value of Circulating miR-202 in Early-Stage Breast Cancer in South Korea

Background and objectives: Breast cancer is the most common cancer among women worldwide. Early stage diagnosis is important for predicting increases in treatment success rates and decreases in patient mortality. Recently, circulating biomarkers such as circulating tumor cells, circulating tumor DNA, exosomes, and circulating microRNAs have been examined as blood-based markers for the diagnosis of breast cancer. Although miR-202 has been studied for its function or expression in breast cancer, its potential diagnostic value in a clinical setting remains elusive and miR-202 has not been investigated in South Korea. In this study, we aimed to evaluate the diagnostic utility of miR-202 in plasma samples of breast cancer patients in South Korea. Materials and Methods: We investigated miR-202 expression in the plasma of 30 breast cancer patients during diagnosis along with 30 healthy controls in South Korea by quantitative reverse transcription PCR. Results: The results showed that circulating miR-202 levels were significantly elevated in the breast cancer patients compared with those in healthy controls (p < 0.001). The sensitivity and specificity of circulating miR-202 were 90.0% and 93.0%, respectively. Additionally, circulating miR-202 showed high positivity at early stage. The positive rate of miR-202 was as follows: 100% (10/10) for stage I, 90% (9/10) for stage II, and 80% (8/10) for stage III. miR-202 was also a predictor of a 9.6-fold high risk for breast cancer (p < 0.001). Conclusions: Additional alternative molecular biomarkers for diagnosis and management of pre-cancer patients are needed. Circulating miR-202 might be potential diagnostic tool for detecting early stage breast cancer.

LNC942 promoting METTL14-mediated m6A methylation in breast cancer cell proliferation and progression

Increasing evidence supports that long noncoding RNAs (lncRNAs) act as master regulators involved in tumorigenesis and development at the N6-methyladenine (m⁶A) epigenetic modification level. However, the underlying regulatory mechanism in breast cancer (BRCA) remains elusive. Here, we unveil that LINC00942 (LNC942) exerts its functions as an oncogene in promoting METTL14-mediated m⁶A methylation and regulating the expression and stability of its target genes CXCR4 and CYP1B1 in BRCA initiation and progression. Specifically, LNC942 and METTL14 were significantly upregulated accompanied with the upregulation of m⁶A levels in BRCA cells and our included BRCA cohorts (n = 150). Functionally, LNC942 elicits potent oncogenic effects on promoting cell proliferation and colony formation and inhibiting cell apoptosis, subsequently elevating METTL14-mediated m⁶A methylation levels and its associated mRNA stability and protein expression of CXCR4 and CYP1B1 in BRCA cells. Mechanistically, LNC942 directly recruits METTL14 protein by harboring the specific recognize sequence (+176-+265), thereby stabilized the expression of downstream targets of LNC942 including CXCR4 and CYP1B1 through posttranscriptional m⁶A methylation modification in vitro and in vivo. Therefore, our results uncover a novel LNC942-METTL14-CXCR4/CYP1B1 signaling axis, which provides new targets and crosstalk m⁶A epigenetic modification mechanism for BRCA prevention and treatment.

microRNAs in the Antitumor Immune Response and in Bone Metastasis of Breast Cancer: From Biological Mechanisms to Therapeutics

Breast cancer is the most common type of cancer in women, and the occurrence of metastasis drastically worsens the prognosis and reduces overall survival. Understanding the biological mechanisms that regulate the transformation of malignant cells, the consequent metastatic transformation, and the immune surveillance in the tumor progression would contribute to the development of more effective and targeted treatments. In this context, microRNAs (miRNAs) have proven to be key regulators of the tumor-immune cells crosstalk for the hijack of the immunosurveillance to promote tumor cells immune escape and cancer progression, as well as modulators of the metastasis formation process, ranging from the preparation of the metastatic site to the transformation into the migrating phenotype of tumor cells. In particular, their deregulated expression has been linked to the aberrant expression of oncogenes and tumor suppressor genes to promote tumorigenesis. This review aims at summarizing the role and functions of miRNAs involved in antitumor immune response and in the metastasis formation process in breast cancer. Additionally, miRNAs are promising targets for gene therapy as their modulation has the potential to support or inhibit specific mechanisms to negatively affect tumorigenesis. With this perspective, the most recent strategies developed for miRNA-based therapeutics are illustrated.

The novel microRNAs hsa-miR-nov7 and hsa-miR-nov3 are over-expressed in locally advanced breast cancer

miRNAs are an important class of small non-coding RNAs, which play a versatile role in gene regulation at the post-transcriptional level. Expression of miRNAs is often deregulated in human cancers. We analyzed small RNA massive parallel sequencing data from 50 locally advanced breast cancers aiming to identify novel breast cancer related miRNAs. We successfully predicted 10 novel miRNAs, out of which 2 (hsa-miR-nov3 and hsa-miR-nov7) were recurrent. Applying high sensitivity qPCR, we detected these two microRNAs in 206 and 214 out of 223 patients in the study from which the initial cohort of 50 samples were drawn. We found hsa-miR-nov3 and hsa-miR-nov7 both to be overexpressed in tumor versus normal breast tissue in a separate set of 13 patients (p = 0.009 and p = 0.016, respectively) from whom both tumor tissue and normal tissue were available. We observed hsa-miR-nov3 to be expressed at higher levels in ER-positive compared to ER-negative tumors (p = 0.037). Further stratifications revealed particularly low levels in the her2-like and basal-like cancers compared to other subtypes (p = 0.009 and 0.040, respectively). We predicted target genes for the 2 microRNAs and identified inversely correlated genes in mRNA expression array data available from 203 out of the 223 patients. Applying the KEGG and GO annotations to target genes revealed pathways essential to cell development, communication and homeostasis. Although a weak association between high expression levels of hsa-miR-nov7 and poor survival was observed, this did not reach statistical significance. hsa-miR-nov3 expression levels had no impact on patient survival.