MicroRNAs miR-7 and miR-340 predict response to neoadjuvant chemotherapy in breast cancer

MiR-301b-3p can be used as a Potential Marker for the Diagnosis of Lung Adenocarcinoma

BACKGROUND

The involvement of aberrantly expressed miR-301b-3p has been discovered in diverse human tumors. Our study was primarily centered around the role of miR-301b-3p in diagnosing lung adenocarcinoma (LUAD).

METHOD

We used the TCGA database to download the TCGA-LUAD dataset and selected miR- 301b-3p as the object of our study by differential expression analysis of miRNAs combined with previous studies. The LUAD diagnostic model was constructed utilizing machine learning based on miR-301b-3p expression. The predictive performance of the diagnostic model was found to be excellent by ROC curves combined with the clinical information of the dataset samples. GSEA, GO, and KEGG enrichment analyses demonstrated that miR-301b-3p may mediate the cell cycle by regulating the expression of hormones. Subsequently, combined with tumor immunity and mutation analysis, it was found that patients in the low-expression group had better immune infiltration, indicating that their response rate to immunotherapy may be relatively high. Finally, a mouse xenograft model was constructed to verify how miR-301b-3p affected LUAD progression in mice.

RESULT

The results illustrated that overexpressed miR-301b-3p could cause faster tumor growth in mice. On the contrary, the growth of LUAD could be impeded by the downregulated miR-301b-3p expression. It was suggested that miR-301b-3p had a crucial part in LUAD progression.

CONCLUSION

Overall, the diagnostic performance of the LUAD diagnostic model constructed based on miR-301b-3p is great, and the model can be used as a potential diagnostic marker for LUAD to provide new ideas for clinical diagnosis.

EBV and 1q Gains Affect Gene and miRNA Expression in Burkitt Lymphoma

Abnormalities of the long arm of chromosome 1 (1q) represent the most frequent secondary chromosomal aberrations in Burkitt lymphoma (BL) and are observed almost exclusively in EBV-negative BL cell lines (BL-CLs). To verify chromosomal abnormalities, we cytogenetically investigated EBV-negative BL patient material, and to elucidate the 1q gain impact on gene expression, we performed qPCR with six 1q-resident genes and analyzed miRNA expression in BL-CLs. We observed 1q aberrations in the form of duplications, inverted duplications, isodicentric chromosome idic(1)(q10), and the accumulation of 1q12 breakpoints, and we assigned 1q21.2-q32 as a commonly gained region in EBV-negative BL patients. We detected MCL1, ARNT, MLLT11, PDBXIP1, and FCRL5, and 64 miRNAs, showing EBV- and 1q-gain-dependent dysregulation in BL-CLs. We observed MCL1, MLLT11, PDBXIP1, and 1q-resident miRNAs, hsa-miR-9, hsa-miR-9*, hsa-miR-92b, hsa-miR-181a, and hsa-miR-181b, showing copy-number-dependent upregulation in BL-CLs with 1q gains. MLLT11, hsa-miR-181a, hsa-miR-181b, and hsa-miR-183 showed exclusive 1q-gains-dependent and FCRL5, hsa-miR-21, hsa-miR-155, hsa-miR-155*, hsa-miR-221, and hsa-miR-222 showed exclusive EBV-dependent upregulation. We confirmed previous data, e.g., regarding the EBV dependence of hsa-miR-17-92 cluster members, and obtained detailed information considering 1q gains in EBV-negative and EBV-positive BL-CLs. Altogether, our data provide evidence for a non-random involvement of 1q gains in BL and contribute to enlightening and understanding the EBV-negative and EBV-positive BL pathogenesis.

HDAC Inhibitor SAHA Alleviates Pyroptosis by up-regulating miR-340 to Inhibit NEK7 Signaling in Subarachnoid Hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) is a cerebral hemorrhagic disease with a high disability and fatality rate. Cell pyroptosis is involved in the brain injury following SAH. Here, we explored the effect of HDAC inhibitor SAHA against cell pyroptosis after SAH.

METHODS

The rat SAH model was established by endovascular perforation and the rat microglia were treated with 25 μm oxyhemoglobin (OxyHb) for 24 h to mimic SAH model in vitro. Neurological score and brain edema were assessed in rat SAH model. TUNEL staining detected apoptosis. qRT-PCR and western blotting were employed to detect expression levels of miR-340, NEK7 and inflammatory cytokines. ELISA assay determined the secretion of IL-1β and IL-18 in rat serum and cell supernatant. A lactate dehydrogenase (LDH) kit measured the LDH activity in rat primary microglia. Microglia pyroptosis was detected by flow cytometry. RIP and dual luciferase reporter assays confirmed the binding relationship between miR-340 and NEK7.

RESULTS

SAHA alleviated neurological dysfunction, inflammatory injury and microglia pyroptosis in SAH rats. SAHA suppressed LDH release, inflammatory factor expression and pyroptosis in microglia treated with OxyHb. Meanwhile, SAHA increased miR-340 expression and inhibited NEK7 level in vivo and in vitro SAH models. Further, miR-340 directly targeted NEK7 to inhibit the NLRP3 signaling pathway. Knockdown of miR-340 or overexpression of NEK7 reversed the suppressive effects of SAHA on microglia inflammation and pyroptosis. Additionally, knockdown of NEK7 impaired microglia inflammation and pyroptosis induced by miR-340 inhibitor.

CONCLUSION

HDAC inhibitor SAHA ameliorates microglia pyroptosis in SAH through triggering miR-340 expression to suppress NEK7 signaling. This novel mechanism provides promise for SAHA in SAH treatment.

Tumor immune microenvironment components and the other markers can predict the efficacy of neoadjuvant chemotherapy for breast cancer

Breast cancer is an epithelial malignant tumor that occurs in the terminal ducts of the breast. Neoadjuvant chemotherapy (NACT) is an important part of breast cancer treatment. Its purpose is to use systemic treatment for some locally advanced breast cancer patients, to decrease the tumor size and clinical stage so that non-operable breast cancer patients can have a chance to access surgical treatment, or patients who are not suitable for breast-conserving surgery can get the opportunity of breast-conserving. However, some patients who do not respond to NACT will lead deterioration in their condition. Therefore, prediction of NACT efficacy in breast cancer is vital for precision therapy. The tumor microenvironment (TME) has a crucial role in the carcinogenesis and therapeutic response of breast cancer. In this review, we summarized the immune cells, immune checkpoints, and other biomarkers in the TME that can evaluate the efficacy of NACT in treating breast cancer. We believe that the detection and evaluation of the TME components in breast cancer are helpful to predict the efficacy of NACT, and the prediction methods are in the prospect. In addition, we also summarized other predictive factors of NACT, such as imaging examination, biochemical markers, and multigene/multiprotein profiling.

Circulating miR-326 could serve as a predictive biomarker for response to neoadjuvant chemotherapy in locally advanced cervical cancer

Background

Clinically, few patients with locally advanced cervical cancer (LACC) are insensitive to neoadjuvant chemotherapy (NACT). Recent studies have reported that circulating microRNAs (miRNAs) may be involved in the response to NACT. The aim of this study was to discover the potential miRNAs that can predict the response to NACT in LACC.

Methods

Pair-matched blood samples of 39 LACC patients before and after receiving NACT were collected. Seven paired samples were used for microRNA microarray analysis. Targeted miRNAs were selected by bioinformatics analysis and were validated by quantitative reverse transcription–polymerase chain reaction (qRT-PCR). All 39 patients were assigned into either the responders group or the non-responders group after NACT. The predictive performance of selected microRNA was evaluated by sensitivity, specificity, accuracy, and the area under the receiver operating characteristic (ROC) curve.

Results

A total of 17 miRNAs downregulated before NACT and upregulated after NACT were selected according to microarray analysis in our previous study, and miR-326 and miR-376a-3p were selected for further exploration. According to the responses and the evaluation criteria, 25 patients reached partial response (PR) and 14 patients remained stable. Further qRT-PCR analysis showed that miR-326 significantly downregulated before NACT and upregulated after NACT in 12 responders (p = 0.02). The expression of miR-376a-3p showed no statistical difference before and after NACT in these 12 responders. Then, miR-326 provided an AUC-ROC of 0.75 (p = 0.04) in the discrimination between the responders and non-responders groups. The cutoff value of ROC for miR-326 to predict the response of NACT was <0.023, the sensitivity was 88.89%, and the specificity was 50%.

Conclusions

The expression of miR-326 significantly upregulated after NACT in responders. miR-326 may be a biomarker for predicting the response to NACT in LACC patients. The results may optimize individualized treatments for LACC patients.

miRNAs as therapeutic predictors and prognostic biomarkers of neoadjuvant chemotherapy in breast cancer: a systematic review and meta-analysis

PURPOSE

Accumulating evidence has shown that microRNAs (miRNAs) are promising biomarkers of neoadjuvant chemotherapy (NAC) response in breast cancer (BC). However, their predictive roles remain controversial. Thus, this systematic review and meta-analysis aimed to describe the role of miRNA expression in NAC response and prognosis in BC to increase statistical power and improve translation.

METHODS

A systematic review of electronic databases for relevant studies was conducted following PRISMA guidelines. Data were extracted, collated, and combined by odds ratio (OR) and hazard ratio (HR) with 95% confidence intervals (CIs) to estimate the strength of the associations.

RESULTS

Of the 560 articles screened, 59 studies were included in our systematic review, and 5 studies were included in the subsequent meta-analysis. Sixty of 123 miRNAs were found to be related with NAC response and an elevated baseline miR-7 level in tissues was associated with a higher pathological complete response rate (OR 5.63; 95% CI 2.15-14.79; P = 0.0004). The prognostic value of 39 miRNAs was also studied. Of them, 26 miRNAs were found to be associated with survival. Pooled HRs indicated that patients with increased levels of serum miR-21 from baseline to the end of the second NAC cycle and from baseline to the end of NAC had a worse disease-free survival than those with decreased levels.

CONCLUSION

Our results highlight that a large number of miRNAs have possible associations with NAC response and prognosis in BC patients. Further well-designed studies are needed to elucidate the molecular mechanisms underlying these associations.

Predictive and Prognostic Value of Non-Coding RNA in Breast Cancer

For decades since the central dogma, cancer biology research has been focusing on the involvement of genes encoding proteins. It has been not until more recent times that a new molecular class has been discovered, named non-coding RNA (ncRNA), which has been shown to play crucial roles in shaping the activity of cells. An extraordinary number of studies has shown that ncRNAs represent an extensive and prevalent group of RNAs, including both oncogenic or tumor suppressive molecules. Henceforth, various clinical trials involving ncRNAs as extraordinary biomarkers or therapies have started to emerge. In this review, we will focus on the prognostic and diagnostic role of ncRNAs for breast cancer.

A 10-miRNA risk score-based prediction model for pathological complete response to neoadjuvant chemotherapy in hormone receptor-positive breast cancer

Patients with hormone receptor (HR)-positive tumors breast cancer usually experience a relatively low pathological complete response (pCR) to neoadjuvant chemotherapy (NAC). Here, we derived a 10-microRNA risk score (10-miRNA RS)-based model with better performance in the prediction of pCR and validated its relation with the disease-free survival (DFS) in 755 HR-positive breast cancer patients (273, 265, and 217 in the training, internal, and external validation sets, respectively). This model, presented as a nomogram, included four parameters: the 10-miRNA RS found in our previous study, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) status, and volume transfer constant (K^trans). Favorable calibration and discrimination of 10-miRNA RS-based model with areas under the curve (AUC) of 0.865, 0.811, and 0.804 were shown in the training, internal, and external validation sets, respectively. Patients who have higher nomogram score (>92.2) with NAC treatment would have longer DFS (hazard ratio=0.57; 95%CI: 0.39-0.83; P=0.004). In summary, our data showed the 10-miRNA RS-based model could precisely identify more patients who can attain pCR to NAC, which may help clinicians formulate the personalized initial treatment strategy and consequently achieves better clinical prognosis for patients with HR-positive breast cancer.

MicroRNA-199a-3p promotes drug sensitivity in triple negative breast cancer by down-regulation of BRCA1

MiR-199a-3p was previously predicted to target tumor suppressor gene BRCA1, which has been linked to cancer onset and therapeutic response. In this study, the effects of miR-199a-3p-mediated BRCA1 dysfunction on triple-negative breast cancer (TNBC) progression and chemosensitivity were assessed. The association between miR-199a-3p and BRCA1 expression was examined in TNBC tumors and verified with luciferase reporter and protein assays. Tumorigenic functions of miR-199a-3p in TNBC cells were investigated by cell proliferation, clonogenic and migration assays. The sensitivities to chemotherapeutic drugs were tested with cisplatin and PARP inhibitor (veliparib) treatments. Mouse xenograft model was used to examine the effects of miR-199a-3p on tumor growth and drug response in vivo. MiR-199a-3p was shown to directly target BRCA1 in TNBC cells, resulting its downregulation and reduced luciferase reporter activity mediated by BRCA1 3'-UTR. Ectopic miR-199a-3p in TNBC cells exerted inhibitory effects on cell proliferation, migration and xenograft tumor growth. Moreover, miR-199a-3p was shown to reverse cisplatin-resistance and sensitize TNBC cells to veliparib, which might be due to repressed DNA repair ability and induced cell apoptosis. Our results demonstrated the tumor suppressive effects of miR-199a-3p on TNBC and induction on chemotherapeutic sensitivities, which were correlated with BRCA1 gene dysfunction. These findings may provide insights into the potential prognostic and therapeutic values of miR-199a-3p in patients with TNBC.

Circulating microRNAs as indicators in the prediction of neoadjuvant chemotherapy response in luminal B breast cancer

PURPOSE

Circulating microRNAs (miRNAs) have been indicated as predictive biomarker for the response to neoadjuvant chemotherapy (NAC) and the prognosis of breast cancer (BC); however, to date the conclusions have been controversial. The biological characteristics of BC were affected by molecular subtypes. Hence, we aimed to investigate the predictive effect of miRNAs on NAC response in luminal B BC patients.

METHODS

Thirty-seven luminal B BC patient under NAC were prospectively enrolled in this study. Based on their clinical, pathological, and comprehensive response, the patients were defined as responder or non-responders, respectively. Circulating miRNAs were isolated from blood samples before and at the middle of NAC, and candidate miRNAs (miR-34a-5p, miR-125b-5p, miR-210, miR-222, miR-375, miR-718, miR-4516, and let-7g) were analyzed by quantitative real-time polymerase chain reaction (PCR). In addition, the association between miRNAs and disease-free survival (DFS) was examined.

RESULTS

miR-718, miR-4516, miR-210, and miR-125b-5p were found to be specific miRNAs associated with chemo-sensitivity of luminal B HER2 negative patients (n = 24). In the luminal B HER2 positive cohort (n = 13), dynamics of miR-222 and let-7g correlated with pathological response. Treatment-induced increase in miR-34a-5p in the responders except who reached pathologic complete response (pCR) was consistently identified across all luminal B patients and its two subgroups. Finally, after adjustments for Neo-Bioscore, patients with increased levels of miR-125b-5p during NAC had a worse DFS than those with decreased levels (HR = 5.86, 95% CI = 1.39-24.62, p = 0.016).

CONCLUSION

Specific circulating miRNAs were identified as predictive markers for NAC response and prognosis in luminal B BC. The underlying mechanism needs further studies.

Molecular Biomarkers Predict Pathological Complete Response of Neoadjuvant Chemotherapy in Breast Cancer Patients: Review

Simple Summary

Breast cancer is the most common cancer in women worldwide. Although many studies have aimed to understand the genetic basis of breast cancer, leading to increasingly accurate diagnoses, only a few molecular biomarkers are used in clinical practice to predict response to therapy. Current studies aim to develop more personalized therapies to decrease the adverse effects of chemotherapy. Personalized medicine not only requires clinical, but also molecular characterization of tumors, which allows the use of more effective drugs for each patient. The aim of this study was to identify potential molecular biomarkers that can predict the response to therapy after neoadjuvant chemotherapy in patients with breast cancer. In this review, we summarize genomic, transcriptomic, and proteomic biomarkers that can help predict the response to therapy.

Abstract

Neoadjuvant chemotherapy (NAC) is often used to treat locally advanced disease for tumor downstaging, thus improving the chances of breast-conserving surgery. From the NAC response, it is possible to obtain prognostic information as patients may reach a pathological complete response (pCR). Those who do might have significant advantages in terms of survival rates. Breast cancer (BC) is a heterogeneous disease that requires personalized treatment strategies. The development of targeted therapies depends on identifying biomarkers that can be used to assess treatment efficacy as well as the discovery of new and more accurate therapeutic agents. With the development of new “OMICS” technologies, i.e., genomics, transcriptomics, and proteomics, among others, the discovery of new biomarkers is increasingly being used in the context of clinical practice, bringing us closer to personalized management of BC treatment. The aim of this review is to compile the main biomarkers that predict pCR in BC after NAC.

The Role of MicroRNA as Clinical Biomarkers for Breast Cancer Surgery and Treatment

Breast cancer is the most common cancer diagnosed in women. In recent times, survival outcomes have improved dramatically in accordance with our enhanced understanding of the molecular processes driving breast cancer proliferation and development. Refined surgical approaches, combined with novel and targeted treatment options, have aided the personalisation of breast cancer patient care. Despite this, some patients will unfortunately succumb to the disease. In recent times, translational research efforts have been focused on identifying novel biomarkers capable of informing patient outcome; microRNAs (miRNAs) are small non-coding molecules, which regulate gene expression at a post-transcriptional level. Aberrant miRNA expression profiles have been observed in cancer proliferation and development. The measurement and correlation of miRNA expression levels with oncological outcomes such as response to current conventional therapies, and disease recurrence are being investigated. Herein, we outline the clinical utility of miRNA expression profiles in informing breast cancer prognosis, predicting response to treatment strategies as well as their potential as therapeutic targets to enhance treatment modalities in the era of precision oncology.

Significance of miR-141 and miR-340 in cervical squamous cell carcinoma

Background

We investigated the expression and clinical significance of miR-141 and miR-340 in cervical squamous cell carcinoma (CSCC).

Methods

Expression of miR-141 and miR-340 in CSCC, high-grade squamous intraepithelial lesion (HSIL), and normal cervical squamous epithelium were detected by qRT-PCR. PTEN was assessed by immunohistochemistry. Their relationship with clinicopathological features was analyzed.

Results

The changes of miR-141 and miR-340 were different in CSCC, HSIL, and normal squamous epithelium (P = 0.030). miR-141 expression was statistically significant in gross type, differentiation, uterine corpus invasion, nerve invasion, vagina invasion, and FIGO stage in CSCC (P < 0.05). miR-340 expression was related to tumor size, differentiation, nerve invasion, lymph node metastasis, and FIGO stage in CSCC (P < 0.05). miR-141 and miR-340 expressions were statistically significant in different ages (P < 0.05) in HSIL. The AUC of miR-141 in CSCC diagnosis and that of miR-340 in HSIL diagnosis were 0.893 and 0.764, respectively. The sensitivity and the specificity of miR-141 for diagnosis of CSCC were 95.0% and 60.8%, respectively, while those of miR-340 for diagnosis of HSIL were 90.0 and 48.6%, respectively. miR-141 and miR-340 expressions are associated with PTEN expression (P = 0.002 and P < 0.001).

Conclusion

miR-141 and miR-340 may be associated with their target gene PTEN and involved in the carcinogenesis of cervical squamous epithelium.

The Role of miRNA-7 in the Biology of Cancer and Modulation of Drug Resistance

MicroRNAs (miRNAs, miRs) are small non-coding RNA (ncRNA) molecules capable of regulating post-transcriptional gene expression. Imbalances in the miRNA network have been associated with the development of many pathological conditions and diseases, including cancer. Recently, miRNAs have also been linked to the phenomenon of multidrug resistance (MDR). MiR-7 is one of the extensively studied miRNAs and its role in cancer progression and MDR modulation has been highlighted. MiR-7 is engaged in multiple cellular pathways and acts as a tumor suppressor in the majority of human neoplasia. Its depletion limits the effectiveness of anti-cancer therapies, while its restoration sensitizes cells to the administered drugs. Therefore, miR-7 might be considered as a potential adjuvant agent, which can increase the efficiency of standard chemotherapeutics.

Interplay between p53 and non-coding RNAs in the regulation of EMT in breast cancer

The epithelial-mesenchymal transition (EMT) plays a pivotal role in the differentiation of vertebrates and is critically important in tumorigenesis. Using this evolutionarily conserved mechanism, cancer cells become drug-resistant and acquire the ability to escape the cytotoxic effect of anti-cancer drugs. In addition, these cells gain invasive features and increased mobility thereby promoting metastases. In this respect, the process of EMT is critical for dissemination of solid tumors including breast cancer. It has been shown that miRNAs are instrumental for the regulation of EMT, where they play both positive and negative roles often as a part of a feed-back loop. Recent studies have highlighted a novel association of p53 and EMT where the mutation status of p53 is critically important for the outcome of this process. Interestingly, p53 has been shown to mediate its effects via the miRNA-dependent mechanism that targets master-regulators of EMT, such as Zeb1/2, Snail, Slug, and Twist1. This regulation often involves interactions of miRNAs with lncRNAs. In this review, we present a detailed overview of miRNA/lncRNA-dependent mechanisms that control interplay between p53 and master-regulators of EMT and their importance for breast cancer.

miR-340: A multifunctional role in human malignant diseases

MicroRNAs (miRNAs) are a class of short non-coding RNAs of approximately 22 nucleotides in length, which function by binding to the 3' UTR sequences of their target mRNAs. It has been reported that dysregulated miRNAs play pivotal roles in numerous diseases, including cancers, such as gastric, breast, colorectal, ovarian, and other cancers. Recent research efforts have been devoted to translating these basic discoveries into clinical applications that could improve the therapeutic outcome in patients with cancer. Early studies have shown that miR-340 may act either as an oncogene or a tumor suppressor by targeting genes related to proliferation, apoptosis, and metastasis, as well as those associated with diagnosis, treatment, chemoresistance, and prognosis. miR-340 has been shown to have a role in other diseases, such as autoimmune diseases, acute stroke, and alcoholic steatohepatitis. Nevertheless, the roles of miR-340 in human malignancies are still unclear, and the associated mechanisms are complex, involving a variety of signaling pathways, such as Wnt/β-catenin and the JAK-STAT pathways. Herein, we review the crucial roles of miR-340 in human cancers through the analysis of the latest research studies, with the aim of clarifying miR-340 function in malignant disease diagnosis, treatment, and prognosis, and to propose further investigations.

Mirna21 Expression in the Breast Cancer Tumor Tissue is Independent of Neoadjuvant Chemotherapy

Introduction

MicroRNA-21 (miRNA-21) has been described as one of the most significantly upregulated miRNAs in human breast cancer. However, limited knowledge exists on miRNA-21 expression in breast cancer tissue after neoadjuvant chemotherapy (NAC).

Purpose

The aim of this study was to assess miRNA-21 expression in the tumor tissues of Brazilian patients with breast cancer who underwent NAC and its correlation with clinicopathological variables.

Patients and Methods

Utilizing qRT-PCR, miRNA-21 expression in tumor tissue was measured in a cohort of female patients with breast cancer who underwent NAC. The correlation of miRNA-21 expression with breast cancer molecular subtypes and other clinicopathological variables was also assessed.

Results

A total of 55 patients were included in the study, and 28 (50.9%) underwent NAC. miRNA-21 was upregulated in patients with breast cancer, regardless of previous exposure to chemotherapy, molecular subtypes, tumor-node-metastasis (TNM) staging and lymph node status of the axilla. miRNA-21 expression did not differ between patients with breast cancer who achieved a pathologic complete response after NAC and healthy controls.

Conclusion

miRNA-21 was upregulated in the tumor tissue of Brazilian patients with breast cancer regardless of NAC treatment, which reinforces its role as an “oncomiR” and a potential biomarker.

Analysis of microRNA regulating cell cycle-related tumor suppressor genes in endometrial cancer patients

Endometrial cancer remains the most common malignancy of the female genital system in developed countries. Tumor suppressor genes are responsible for controlling the cells fate in the cell cycle and preventing cancerogenesis. Gene expression affects cancer progression and is modulated by microRNAs defined as both tumor suppressors and oncogenes. These molecules indirectly regulate multiple processes like cell proliferation, differentiation and apoptosis. The aim of this study was to analyze miRNAs expression that can regulate the activity of tumor suppressor genes related to the cell cycle in patients with endometrioid endometrial cancer. The study group consisted of 12 samples that met the inclusion criteria from a total of 48 obtained. The 12 samples were used to analyze microRNA expression. Complementary miRNAs were identified using TargetScan Database and statistical analysis. MicroRNAs were determined for the tumor suppressor genes: CYR61, WT1, TSPYL5, HNRNPA0, BCL2L1 and BAK1. All the miRNAs were complementary to the described target genes based on TargetScan Database. There were five miRNAs differentially expressed that can regulate tumor suppressor genes related to the cell cycle. The distinguished miRNAs: mir-340-3p, mir-1236-5p, mir-874-3p, mir-873-5p.2 and mir-548-5p were differentially expressed in endometrial cancer in comparison to the control. Among the distinguished miRNAs, the most promising is mir-874-3p, which may have an important role in endometrial adenocarcinoma proliferation.

Prognostic and Clinicopathological Significance of MiR-155 in Breast Cancer: A Systematic Review

There is an unmet need for novel non-invasive prognostic molecular tumour markers for breast cancer (BC). Accumulating evidence shows that miR-155 plays a pivotal role in tumorigenesis. Generally, miR-155 is considered an oncogenic miRNA promoting tumour growth, angiogenesis and aggressiveness of BC. Therefore, many researchers have focused on its use as a prognostic biomarker and therapeutic target. However, its prognostic value for BC patients remains controversial. To address this issue, the present systematic review aims to summarize the available evidence and give a picture of a prognostic significance of miR-155 in BC pathology. All eligible studies were searched on PubMed and EMBASE databases through various search strategies. Starting from 289 potential eligible records, data were examined from 28 studies, comparing tissue and circulating miR-155 expression levels with clinicopathological features and survival rates in BC patients. We discuss the pitfalls and challenges that need to be assessed to understand the power of miR-155 to respond to real clinical needs, highlighting the consistency, robustness or lack of results obtained to sate in translating this molecule to clinical practice. Our paper suggests that the prognostic role of miR-155 in the management of BC needs to be further verified.

CircRNAs: biogenesis, functions, and role in drug-resistant Tumours

Targeted treatment, which can specifically kill tumour cells without affecting normal cells, is a new approach for tumour therapy. However, tumour cells tend to acquire resistance to targeted drugs during treatment. Circular RNAs (circRNAs) are single-stranded RNA molecules with unique structures and important functions. With the development of RNA sequencing technology, circRNAs have been found to be widespread in tumour-resistant cells and to play important regulatory roles. In this review, we present the latest advances in circRNA research and summarize the various mechanisms underlying their regulation. Moreover, we review the role of circRNAs in the chemotherapeutic resistance of tumours and explore the clinical value of circRNA regulation in treating tumour resistance.

Unsupervised discovery of phenotype-specific multi-omics networks

MOTIVATION

Complex diseases often involve a wide spectrum of phenotypic traits. Better understanding of the biological mechanisms relevant to each trait promotes understanding of the etiology of the disease and the potential for targeted and effective treatment plans. There have been many efforts towards omics data integration and network reconstruction, but limited work has examined the incorporation of relevant (quantitative) phenotypic traits.

RESULTS

We propose a novel technique, sparse multiple canonical correlation network analysis (SmCCNet), for integrating multiple omics data types along with a quantitative phenotype of interest, and for constructing multi-omics networks that are specific to the phenotype. As a case study, we focus on miRNA-mRNA networks. Through simulations, we demonstrate that SmCCNet has better overall prediction performance compared to popular gene expression network construction and integration approaches under realistic settings. Applying SmCCNet to studies on chronic obstructive pulmonary disease (COPD) and breast cancer, we found enrichment of known relevant pathways (e.g. the Cadherin pathway for COPD and the interferon-gamma signaling pathway for breast cancer) as well as less known omics features that may be important to the diseases. Although those applications focus on miRNA-mRNA co-expression networks, SmCCNet is applicable to a variety of omics and other data types. It can also be easily generalized to incorporate multiple quantitative phenotype simultaneously. The versatility of SmCCNet suggests great potential of the approach in many areas.

AVAILABILITY AND IMPLEMENTATION

The SmCCNet algorithm is written in R, and is freely available on the web at https://cran.r-project.org/web/packages/SmCCNet/index.html.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

miR-7 Reverses Breast Cancer Resistance To Chemotherapy By Targeting MRP1 And BCL2

Background

MicroRNAs (miRNAs) are a class of non‐coding RNAs that have been linked with breast cancer chemoresistance, which is a major clinical problem causing disease relapse and poor prognosis. miR-7 exerts several tumor suppressive activities.

Purpose

This study was designed to clarify whether and how miR-7 regulates breast cancer chemoresistance.

Methods

miR-7 level in breast cancer was determined by qRT-PCR analysis. Cell viability was assessed by MTS assay to quantify the IC₅₀ value of paclitaxel and carboplatin. The targets of miR-7 were confirmed by luciferase reporter assay.

Results

Higher miR-7 expression predicts better pathological complete response (pCR) of breast cancer patients receiving paclitaxel/carboplatin chemotherapy. In vitro, miR-7 sensitizes breast cancer cell lines (MCF-7 and MDA-MB-231) to paclitaxel and carboplatin, alone and in combination. In addition, we reveal that both the multidrug resistance-associated protein 1 (MRP1) and anti-apoptotic B cell lymphoma 2 (BCL2) are targets of miR-7 in breast cancer cells. Furthermore, miR-7-induced sensitization of breast cancer to paclitaxel/carboplatin is markedly reversed by restoration of MRP1 and BCL2.

Conclusion

These findings show that miR-7 reverses breast cancer chemoresistance through suppressing MRP1 and BCL2, and also suggest that miR-7 may possess a predictive value and represent a therapeutic target in breast cancer chemotherapy.

Circulating non‑coding RNA‑biomarker potential in neoadjuvant chemotherapy of triple negative breast cancer?

Due to the positive association between neoadjuvant chemotherapy (NACT) and the promising early response rates of patients with triple negative breast cancer (TNBC), including probabilities of pathological complete response, NACT is increasingly used in TNBC management. Liquid biopsy-based biomarkers with the power to diagnose the early response to NACT may support established monitoring tools, which are to a certain extent imprecise and costly. Simple serum- or urine-based analyses of non-coding RNA (ncRNA) expression may allow for fast, minimally-invasive testing and timely adjustment of the therapy regimen. The present study investigated breast cancer-related ncRNAs [microRNA (miR)-7, -9, -15a, -17, -18a, -19b, -21, -30b, -222 and -320c, PIWI-interacting RNA-36743 and GlyCCC2] in triple positive BT-474 cells and three TNBC cell lines (BT-20, HS-578T and MDA-MB-231) treated with various chemotherapeutic agents using reverse transcription-quantitative PCR. Intracellular and secreted microvesicular ncRNA expression levels were analysed using a multivariable statistical regression analysis. Chemotherapy-driven effects were investigated by analysing cell cycle determinants at the mRNA and protein levels. Serum and urine specimens from 8 patients with TNBC were compared with 10 healthy females using two-sample t-tests. Samples from the patients with TNBC were compared at two time points. Chemotherapeutic treatments induced distinct changes in ncRNA expression in TNBC cell lines and the BT-474 cell line in intra- and extracellular compartments. Serum and urine-based ncRNA expression analysis was able to discriminate between patients with TNBC and controls. Time point comparisons in the urine samples of patients with TNBC revealed a general rise in the level of ncRNA. Serum data suggested a potential association between piR-36743, miR-17, -19b and -30b expression levels and an NACT-driven complete clinical response. The present study highlighted the potential of ncRNAs as liquid biopsy-based biomarkers in TNBC chemotherapy treatment. The ncRNAs tested in the present study have been previously investigated for their involvement in BC or TNBC chemotherapy responses; however, these previous studies were restricted to patient tissue or in vitro models. The data from the present study offer novel insight into ncRNA expression in liquid samples from patients with TNBC, and the study serves as an initial step in the evaluation of ncRNAs as diagnostic biomarkers in the monitoring of TNBC therapy.

miR-532-5p promotes breast cancer proliferation and migration by targeting RERG

Aberrant expression of microRNAs (miRNAs/miRs) mediates the initiation and progression of breast cancer. Therefore, it is important to investigate the molecular mechanisms of miRNAs and their effects on breast cancer progression. In the present study, miR-532-5p was highly expressed in breast cancer tissues compared with normal tissues. In addition, expression of ras-related and estrogen-regulated growth inhibitor (RERG), a tumor suppressor in breast cancer, was negatively correlated with miR-532-5p expression. Inhibition of miR-532-5p significantly elevated RERG at both mRNA and protein levels and inactivated the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. Overexpression of miR-532-5p decreased RERG expression and activated the MAPK/ERK signaling in breast cancer cell line MDA-MB-231. Bioinformatic analysis indicated that RERG 3'-untraslated region contained a putative binding site for miR-532-5p. Dual luciferase assay further validated RERG as a target gene of miR-532-5p. Notably, downregulation of miR-532-5p inhibited MDA-MB-231 cell proliferation and migration, which was partially attenuated upon RERG knockdown. In conclusion, the current study revealed an oncogenic role of miR-532-5p in breast cancer cells via direct targeting of RERG expression.

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.

Breast cancer: Occluded role of mitochondria N-acetylserotonin/melatonin ratio in co-ordinating pathophysiology

A plethora of factors contribute to the biochemical underpinnings of breast cancer, in the absence of any clear, integrative framework. This article proposes that melatonergic pathway regulation within mitochondria provides an integrative framework for the wide array of data driving breast cancer pathophysiology. As melatonin is toxic to breast cancer cells, its production within mitochondria poses a significant challenge to breast cancer cell survival. Consequently, the diverse plasticity in breast cancer cells may arise from a requirement to decrease mitochondria melatonin synthesis. The aryl hydrocarbon receptor role in breast cancer pathophysiology may be mediated by an increase in cytochrome P450 (CYP)1b1 in mitochondria, leading to the backward conversion of melatonin to N-acetylserotonin (NAS). NAS has distinct effects to melatonin, including its activation of the tyrosine receptor kinase B (TrkB) receptor. TrkB activation significantly contributes to breast cancer cell survival and migration. However, the most important aspect of NAS induction by CYP1b1 in breast cancer cells is the prevention of melatonin effects in mitochondria. Many of the changes occurring in breast cancer cells arise from the need to regulate this pathway in mitochondria, allowing this to provide a framework that integrates a host of previously disparate data, including: microRNAs, estrogen, 14-3-3 proteins, sirtuins, glycolysis, oxidative phosphorylation, indoleamine 2,3-dioxygenase and the kynurenine pathways. It is also proposed that this framework provides a pathoetiological model incorporating the early developmental regulation of the gut microbiome that integrates breast cancer risk factors, including obesity. This has significant treatment, prevention and research implications.

Why the Gold Standard Approach by Mammography Demands Extension by Multiomics? Application of Liquid Biopsy miRNA Profiles to Breast Cancer Disease Management

In the global context, the epidemic of breast cancer (BC) is evident for the early 21st century. Evidence shows that national mammography screening programs have sufficiently reduced BC related mortality. Therefore, the great utility of the mammography-based screening is not an issue. However, both false positive and false negative BC diagnosis, excessive biopsies, and irradiation linked to mammography application, as well as sub-optimal mammography-based screening, such as in the case of high-dense breast tissue in young females, altogether increase awareness among the experts regarding the limitations of mammography-based screening. Severe concerns regarding the mammography as the “golden standard” approach demanding complementary tools to cover the evident deficits led the authors to present innovative strategies, which would sufficiently improve the quality of the BC management and services to the patient. Contextually, this article provides insights into mammography deficits and current clinical data demonstrating the great potential of non-invasive diagnostic tools utilizing circulating miRNA profiles as an adjunct to conventional mammography for the population screening and personalization of BC management.

miR-340-5p Suppresses Aggressiveness in Glioblastoma Multiforme by Targeting Bcl-w and Sox2

Glioblastoma multiforme (GBM), a particularly aggressive type of malignant brain tumor, has a high mortality rate. Bcl-w, an oncogene, is reported to enhance cell survival, proliferation, epithelial-mesenchymal transition (EMT), migratory and invasive abilities, and stemness maintenance in a variety of cancer cell types, including GBM. In this study, we confirmed that Bcl-w-induced conditional medium (CM) enhances tumorigenic phenotypes of migration, invasiveness, and stemness maintenance. Notably, platelet-derived growth factor-A (PDGF-A) expression, among other factors of the tumor environment, was increased by CM of Bcl-w-overexpressing cells, prompting investigation of the potential correlation between Bcl-w and PDGF-A and their effects on GBM malignancy. Bcl-w and PDGF-A levels were positively regulated and increased tumorigenicity by Sox2 activation in GBM cells. miR-340-5p was further identified as a direct inhibitor of Bcl-w and Sox2. Overexpression of miR-340-5p reduced mesenchymal traits, cell migration, invasion, and stemness in GBM through attenuating Bcl-w and Sox2 expression. Our novel findings highlight the potential utility of miR-340-5p as a therapeutic agent for glioblastoma multiforme through inhibitory effects on Bcl-w-induced PDGF-A and Sox2 activation.

Identification of prognostic biomarkers for breast cancer based on miRNA and mRNA co-expression network

PURPOSE

Breast cancer (BC) remains a serious health threat for women due to its high incidence and the trend of rejuvenation. Accumulating evidence has highlighted that microRNAs (miRNAs) and messenger RNAs (mRNAs) could play important roles in various biological processes involved in the pathogenesis of BC. The present study aimed to identify potential prognostic biomarkers associated with BC.

METHODS

Here, original gene expression profiles of patients with BC was downloaded from The Cancer Genome Atlas (TCGA) database. TargetScan, miRDB, and miRTarBase databases were used to predict the target genes of prognostic-related differentially expressed miRNAs (DEMs). Subsequently, functional enrichment analysis and topological analysis were performed on the overlaps of target genes and differentially expressed mRNAs (DEGs), and Kaplan-Meier analysis was used to predict prognosis-related target genes to identify prognostic biomarkers.

RESULTS

A total of 218 DEMs and 2222 DEGs were extracted in which eight miRNAs were associated with prognosis, and 278 target DEGs were screened out incorporated into functional enrichment analysis and protein-protein interaction network visualization studies. Additionally, five hub genes (CXCL12, IGF1, LEF1, MMP1, and RACGAP1) were observed as potential biomarkers for BC prognosis through survival analysis.

CONCLUSION

We performed a distinctive correlation analysis of miRNA-mRNA in BC patients, and identified eight miRNAs and five hub genes may be effective biomarkers for the prognosis of BC patients.

MicroRNA-143 is Associated With Pathological Complete Response and Regulates Multiple Signaling Proteins in Breast Cancer

Almost 55% to 80% of patients with breast cancer have an unfavorable pathological complete response to chemotherapy. MicroRNAs are small noncoding RNAs involved in cancer progression; however, their utility as predictors of pathological complete response to neoadjuvant chemotherapy is unclear. Here, we investigated if miR-143 could discriminate between pathological complete response and no-polymerase chain reaction of patients with locally advanced triple negative breast cancer that have received a fluorouracil-cisplatin/paclitaxel-based neoadjuvant treatment. Data showed that miR-143 exhibited a significant low expression (P < .0006) in patients that achieved pathological complete response in comparison to nonresponder group. Receiver operating characteristic curve analysis suggested that miR-143 could be a good predictor of pathological complete response (area under curve = 0.849, P < .0006). Moreover, Kaplan-Meier analysis indicated that before neoadjuvant therapy low levels of miR-143 were associated to increased disease free survival. To gain insights into cellular functions of miR-143, we firstly showed that miR-143 was severely repressed in breast cancer cell lines and tumors in comparison to normal mammary cells and tissues. Ectopic restoration of miR-143 using RNA mimics inhibited both cell proliferation and migration and sensitized breast cancer cells to cisplatin therapy in vitro. To decipher the signaling networks regulated by miR-143, we used a high-throughput enzyme-linked immunosorbent assay-based phosphorylation antibody array. Phospho-proteomic profiling revealed that miR-143 coordinately reduced the protein levels and phosphorylation status of multiple oncoproteins involved in AKT, WNT/β-catenin, SAPK/JNK, FAK, and JAK/STAT signaling pathways. Moreover, low miR-143 and high GSK3-β, RAF1, paxillin, and p21CIP1 expression levels in a large cohort of patients with breast cancer were associated with worst outcome. In summary, miR-143 could be a potential predictor of response to neoadjuvant therapy and it may function as a divergent regulator of diverse signaling networks to suppress cell proliferation and migration in breast cancer.

The Significance Role of microRNA-200c as a Prognostic Factor in Various Human Solid Malignant Neoplasms: A Meta-Analysis

Objective: The aim of this study was to conduct a meta-analysis of 49 relevant studies to evaluate the prognostic value of miRNA-200c in various human malignant neoplasms.

Methods: All relevant studies were identified by searching PubMed, Embase and Web of Science until August 15^st, 2018. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) of miRNA-200c for overall survival (OS) and progression-free survival (PFS)/recurrence-free survival (RFS)/disease-free survival (DFS) were calculated to investigate such associations.

Results: Overall, 49 eligible studies were included in this meta-analysis. Our results showed that high expression of miRNA-200c was significantly correlated with a poor OS in cancer (pooled HR = 1.32, 95% CI: 1.06-1.65), but was not significantly correlated with PFS/RFS/DFS in cancer (pooled HR=1.05, 95% CI: 0.84-1.23). In our subgroup analysis, high miRNA-200c expression predicted a significantly worse OS (pooled HR = 1.50, 95% CI: 1.12-2.01) only in Caucasians. Moreover, high miRNA-200c expression even showed significantly poor OS (pooled HR = 1.88, 95% CI: 1.39-2.54) in blood samples. In addition, a significantly unfavorable OS (pooled HR = 2.69, 95% CI: 1.49-4.85) and (pooled HR = 2.66, 95% CI: 1.07-6.59) associated with up-regulated miRNA-200c expression were observed in breast cancer and endometrial cancer, respectively. Besides, high miRNA-200c expression also showed significantly poor PFS/RFS/DFS (pooled HR=1.66, 95% CI: 1.03-2.67) in breast cancer.

Conclusions: Our findings indicated that high miRNA-200c expression was a promising biomarker for patient survival and disease progression in malignant tumors, especially in breast cancer and endometrial cancer. Considering the insufficient evidence, further large-scale researches and clinical studies were needed to verify these results.

Competing endogenous RNA (ceRNA) cross talk and language in ceRNA regulatory networks: A new look at hallmarks of breast cancer

Breast cancer (BC) is the most frequently occurring malignancy in women worldwide. Despite the substantial advancement in understanding the molecular mechanisms and management of BC, it remains the leading cause of cancer death in women. One of the main reasons for this obstacle is that we have not been able to find the Achilles heel for the BC as a highly heterogeneous disease. Accumulating evidence has revealed that noncoding RNAs (ncRNAs), play key roles in the development of BC; however, the involving of complex regulatory interactions between the different varieties of ncRNAs in the development of this cancer has been poorly understood. In the recent years, the newly discovered mechanism in the RNA world is "competing endogenous RNA (ceRNA)" which proposes regulatory dialogues between different RNAs, including long ncRNAs (lncRNAs), microRNAs (miRNAs), transcribed pseudogenes, and circular RNAs (circRNAs). In the latest BC research, various studies have revealed that dysregulation of several ceRNA networks (ceRNETs) between these ncRNAs has fundamental roles in establishing the hallmarks of BC development. And it is thought that such a discovery could open a new window for a better understanding of the hidden aspects of breast tumors. Besides, it probably can provide new biomarkers and potential efficient therapeutic targets for BC. This review will discuss the existing body of knowledge regarding the key functions of ceRNETs and then highlights the emerging roles of some recently discovered ceRNETs in several hallmarks of BC. Moreover, we propose for the first time the "ceRnome" as a new term in the present article for RNA research.

miRNA in a multiomic context for diagnosis, treatment monitoring and personalized management of metastatic breast cancer

Metastatic breast cancer is characterized by aggressive spreading to distant organs. Despite huge multilevel research, there are still several important challenges that have to be clarified in the management of this disease. Therefore, recent investigations have implemented a modern, multiomic approach with the aim of identifying specific biomarkers for not only early detection but also to predict treatment responses and metastatic spread. Specific attention is paid to short miRNAs, which regulate gene expression at the post-transcriptional level. Aberrant miRNA expression could initiate cancer development, cell proliferation, invasion, migration, metastatic spread or drug resistance. An miRNA signature is, therefore, believed to be a promising biomarker and prediction tool that could be utilized in all phases of carcinogenesis. This article offers comprehensive information about miRNA profiles useful for diagnostic and treatment purposes that may sufficiently advance breast cancer management and improve individual outcomes in the near future.

Identification of microRNA Biomarkers of Response to Neoadjuvant Chemoradiotherapy in Esophageal Adenocarcinoma Using Next Generation Sequencing

BACKGROUND

Clinical trials report improved overall survival following neoadjuvant chemoradiotherapy in patients undergoing surgery for esophageal adenocarcinoma, with a 10-15% survival improvement. MicroRNAs (miRNAs) are small noncoding RNAs that are known to direct the behavior of cancers, including response to treatment. We investigated the ability of miRNAs to predict outcomes after neoadjuvant chemoradiotherapy.

METHODS

Endoscopic biopsies from esophageal adenocarcinomas were obtained before neoadjuvant chemoradiotherapy and esophagectomy. miRNA levels were measured in the biopsies using next generation sequencing and compared with pathological response in the surgical resection, and subsequent survival. miRNA ratios that predicted pathological response were identified by Lasso regression and leave-one-out cross-validation. Association between miRNA ratio candidates and relapse-free survival was assessed using Kaplan-Meier analysis. Cox regression and Harrell's C analyses were performed to assess the predictive performance of the miRNAs.

RESULTS

Two miRNA ratios (miR-4521/miR-340-5p and miR-101-3p/miR-451a) that predicted the pathological response to neoadjuvant chemoradiotherapy were found to be associated with relapse-free survival. Pretreatment expression of these two miRNA ratios, pretreatment tumor differentiation, posttreatment AJCC histopathological tumor regression grading, and posttreatment tumor clearance/margins were significant factors associated with survival in Cox regression analysis. Multivariate analysis of the two ratios together with pretherapy factors resulted in a risk prediction accuracy of 85% (Harrell's C), which was comparable with the prediction accuracy of the AJCC treatment response grading (77%).

CONCLUSIONS

miRNA-ratio biomarkers identified using next generation sequencing can be used to predict disease free survival following neoadjuvant chemoradiotherapy and esophagectomy in patients with esophageal adenocarcinoma.

New emerging roles of microRNAs in breast cancer

BACKGROUND

MicroRNAs constitute a large family of non-coding RNAs, which actively participate in tumorigenesis by regulating a set of mRNAs of distinct signaling pathways. An altered expression of these molecules has been found in different tumorigenic processes of breast cancer, the most common type of cancer in the female population worldwide.

PURPOSE

The objective of this review is to discuss how miRNAs become master regulators in breast tumorigenesis.

METHODS

An integrative review of miRNAs and breast cancer literature from the last 5 years was done on PubMed. We summarize recent works showing that the defects on the biogenesis of miRNAs are associated with different breast cancer characteristics. Then, we show several examples that demonstrate the link between cellular processes regulated by miRNAs and the hallmarks of breast cancer. Finally, we examine the complexity in the regulation of these molecules as they are modulated by other non-coding RNAs and the clinical applications of miRNAs as they could serve as good diagnostic and classification tools.

CONCLUSION

The information presented in this review is important to encourage new directed studies that consider microRNAs as a good tool to improve the diagnostic and treatment alternatives in breast cancer.

Analysis of the complex interaction of CDR1as-miRNA-protein and detection of its novel role in melanoma

Despite improvements in the prevention, diagnosis and treatment of melanoma having developed rapidly, the role of circular RNA CDR1 antisense RNA (CDR1as) in melanoma remains to be elucidated. The aim of the present study was to predict the novel roles of CDR1as in melanoma through novel bioinformatics analysis. In the present study, the circ2Traits database was used to supply information on CDR1as in cancer. CircNet, circBase and circInteractome databases were used to detect the co-expression of CDR1as, microRNAs and proteins. Furthermore, the functions and pathways of the associated proteins were predicted using the Database for Annotation, Visualization and Integrated Discovery. Gene Ontology enrichment analysis suggested that the proteins associated with CDR1as were mainly regulated in the cytoplasm as the molecular protein binding, the biological process of cell division and the endoplasmic reticulum tubular network, which are all involved in cancer-related processes. The Kyoto Encyclopedia of Genes and Genome pathway cell cycle was closely associated with the location of cancer. Co-expression network analysis revealed the associations among CDR1as, microRNAs and proteins. The bioinformatics analysis showed that CDR1as may act as the competing endogenous RNA for the vital genes, which are associated with the invasion and migration of melanoma.

Effects of miR-340 on hepatocellular carcinoma by targeting the DcR3 gene

In hepatocellular carcinoma (HCC), miR-340 plays a vital role in the regulation of tumor occurrence and deterioration, while DcR3 gene is involved in cancer cell proliferation and apoptosis. This study analyzed miR-340 in the serum of patients with HCC and healthy controls. Then, miR-340, DcR3, TGF-β1 and Smad2 expression were measured in HCC tissues and adjacent parts. Relationship between miR-340 and DcR3 was verified. Effects of miR-340 on human HepG2 cell proliferation and apoptosis were explored. miR-340, DcR3, TGF-β1, Smad2 mRNA and protein expression were also determined after miR-340 transfection. Compared with the control, miR-340 was significantly lower in the serum of the HCC patients (p < 0.01). miR-340 was lower in HCC tissues than in adjacent; however, DcR3, TGF-β1 and Smad2 were higher (p < 0.01). Furthermore, luciferase activity was significantly lower in the cells co-transfected with miR-340 mimics and DcR3-3'UTR-WT (p < 0.01), indicating that DcR3 was a target gene of miR-340. Moreover, decreased expression in DcR3, TGF-β1 and Smad2 was detected after miR-340 overexpression (p < 0.01), thus promoting apoptosis and blocking the proliferation of human HepG2 cells (p < 0.05). Furthermore, overexpression of DcR3 could activate the TGF-β1/Smad2 signal transduction pathway and increase the phosphorylation of Smad2. In conclusion, miR-340 plays a suppressive role in HCC development by targeting DcR3 and silencing the TGF-β1/Smad2 signaling pathway.

Increased expression of miR-155 and miR-222 is associated with lymph node positive status

Identification of prognostic molecular markers of breast cancer is extremely important. The spreading out of the primary breast tumour cells to the lymphatic system is at the forefront of symbolising the first signs of distant organ metastasis. Deregulated genes in breast cancer tissues that spread to lymph nodes may show early predictive molecular markers. In the present study, we selected five microRNAs, which play a key function in the invasion-metastasis cascade. We investigated the levels of microRNAs in 80 paired samples of BC and matched adjoining tissues, and we examined the potential relationships between microRNA levels and positive lymph node status. Our results attest that three microRNAs (miR-21, miR-155, miR-222) were significantly up-regulated, whilst miR-205 was substantially down-regulated in BC tissues in relation to normal adjoining tissues in a heterogeneous patient cohort. The high levels of two microRNAs, miR-155 and miR-222, showed a statistical relation with the positive lymph node status, especially in patients that had triple negative BC. Conversely, miR-155 was substantially down-regulated in tumour tissues of patients who received preoperative neoadjuvant chemotherapy (NAC) compared with tumour tissues of patients without NAC in cohorts sub-classified to lymph node positive status. Our findings show evidence that the miR-155 and the miR-222 can be defined as molecular markers in regards to cancer patients to prognosticate spread to the lymph node. They also showed that the miR-155 could have crucial significances in BC treatment.

Differential expression of exosomal miRNAs between breast cancer patients with and without recurrence

BACKGROUND

Exosomal microRNAs (miRNAs) are promising candidate biomarkers for diagnosis or prognosis for breast cancer. We investigated the prognostic role of exosomal miRNAs in serum samples derived from patients with breast cancer and compared miRNA expression between serum and tumor tissues.

METHODS

The miRNA profile derived from exosome between breast cancer patients with recurrence (n = 16) and without recurrence (n = 16) were compared by miRNA PCR array. Further, we examined the expression of miRNAs derived from tissues in the patients with breast cancer with (n = 35) and without recurrence (n = 39) by qRT-PCR.

RESULTS

Of 384 miRNAs, three miRNAs (miR-338-3p, miR-340-5p, and miR-124-3p) were significantly upregulated and eight (miR-29b-3p, miR-20b-5p, miR-17-5p, miR-130a-3p, miR-18a-5p, miR-195-5p, miR-486-5p, and miR-93-5p) were significantly downregulated in the patients with recurrence. We evaluated the expression of the miRNAs in tumor tissues. The patients with recurrence had higher levels of miR-340 at their primary site as well as in the serum. In contrast, miR-195-5p, miR-17-5p, miR-93-5p, and miR-130a-3p, derived from tumor tissues that were downregulated in the serum from patients with recurrence, were higher in the patients with recurrence than in those with no recurrence. In logistic regression analysis, miR-340-5p, miR-17-5p, miR-130a-3p, and miR-93-5p were significantly associated with recurrence.

CONCLUSIONS

Several exosomal miRNAs may be useful biomarkers to predict breast cancer recurrence. We show the different expression patterns of miRNAs between tumor tissues and serum. These findings may suggest selective mechanism of release of exosomal miRNAs by cancer cells to regulate their progression.

Screening circular RNA related to chemotherapeutic resistance in breast cancer

Aim: We aimed to identify circular RNAs (circRNAs) associated with breast cancer chemoresistance. Materials & methods: CircRNA microarray expression profiles were obtained from Adriamycin (ADM) resistant MCF-7 breast cancer cells (MCF-7/ADM) and parental MCF-7 cells and were validated using quantitative real-time reverse transcription PCR. The expression data were analyzed bioinformatically. Results: We detected 3093 circRNAs and identified 18 circRNAs that are differentially expressed between MCF-7/ADM and MCF-7 cells; after validating by quantitative real-time reverse transcription PCR, we predicted the possible miRNAs and potential target genes of the seven upregulated circRNAs using TargetScan and miRanda. The bioinformatics analysis revealed several target genes related to cancer-related signaling pathways. Additionally, we discovered a regulatory role of the circ_0006528-miR-7–5p-Raf1 axis in ADM-resistant breast cancer. Conclusion: These results revealed that circRNAs may play a role in breast cancer chemoresistance and that hsa_circ_0006528 might be a promising candidate for further functional analysis.

The miR-200 family in ovarian cancer

Ovarian cancer (OC) is the most lethal gynecological malignancy. Its insidious nature, manifesting with little to no symptoms until the disease progresses to metastasis, along with a wide diversity of histological subtypes and corresponding clinical behavior, poses significant therapeutic challenges. The genetic profiling of this aggressive tumor and its subtypes has led to the identification of various molecular markers of prognosis. Among these, the miR-200 family of miRNAs appears to play an important role. The deregulated expression of the miR-200 family members has been detected in a variety of OC studies. The present review examines the potential usefulness of the miR-200 family members as prognostic indicators in ovarian cancer and their impact across different OC publications, with a particular focus on prognostic features, such as disease stage, tumor histology, survival and response to chemotherapy. We present the potential usefulness of the miR-200 family genes as prognostic indicators in OC and highlight the tendency that miR-200 overexpression corresponds with an advanced cancer stage.