High expression levels of miR-21 and miR-210 predict unfavorable survival in breast cancer: a systemic review and meta-analysis

Clinical importance of serum miRNA levels in breast cancer patients

There is limited data on the relationship of miRNAs with parameters that may affect surgical management or reflect tumour prognosis. It was aimed to evaluate serum miRNA levels in breast carcinoma cases and reveal the relationship between these levels and prognosis-related factors such as the histological type of the tumour, estrogen receptor, progesterone receptor, Ki-67 index, HER-2neu, E-cadherin, tumour size, CK5/6, CA15.3 levels, number of tumour foci, number of metastatic lymph nodes, and status of receiving neoadjuvant therapy. Thirty-five patients with a histopathologically confirmed breast carcinoma diagnosis in the case group and 35 healthy individuals in the control group were examined. miR-206, miR-17-5p, miR-125a, miR-125b, miR-200a, Let-7a, miR-34a, miR-31, miR-21, miR-155, miR-10b, miR-373, miR-520c, miR-210, miR-145, miR-139-5p, miR-195, miR-99a, miR-497 and miR-205 expression levels in the serum of participants were determined using the Polymerase Chain Reaction method. While serum miR-125b and Let-7a expression levels were significantly higher in breast cancer patients, miR-17-5p, miR-125a, miR-200a, miR-34a, miR-21, miR-99a and miR-497 levels were significantly lower in them. The Let-7a expression level had a statistically significant relationship with breast cancer histological type and HER-2neu parameters, miR-17-5p, miR-125b, Let-7a, miR-34a, miR-21 and miR-99a levels with E-cadherin, miR-34a, miR-99a and miR-497 with CA15.3, miR-125b, miR-200a and miR-34a with the number of metastatic lymph nodes, miR-125a with the number of tumour foci and miR-200a with the status of having the neoadjuvant therapy. Serum miR-17-5p, miR-125a, miR-125b, miR-200a, Let-7a, miR-34a, miR-21, miR-99a and miR-497 expression levels were determined to have predictive and prognostic importance in breast cancer.

Prognostic and diagnostic values of non-coding RNAs as biomarkers for breast cancer: An umbrella review and pan-cancer analysis

Background: Breast cancer (BC) is the most common cancer in women. The incidence and morbidity of BC are expected to rise rapidly. The stage at which BC is diagnosed has a significant impact on clinical outcomes. When detected early, an overall 5-year survival rate of up to 90% is possible. Although numerous studies have been conducted to assess the prognostic and diagnostic values of non-coding RNAs (ncRNAs) in breast cancer, their overall potential remains unclear. In this field of study, there are various systematic reviews and meta-analysis studies that report volumes of data. In this study, we tried to collect all these systematic reviews and meta-analysis studies in order to re-analyze their data without any restriction to breast cancer or non-coding RNA type, to make it as comprehensive as possible. Methods: Three databases, namely, PubMed, Scopus, and Web of Science (WoS), were searched to find any relevant meta-analysis studies. After thoroughly searching, the screening of titles, abstracts, and full-text and the quality of all included studies were assessed using the AMSTAR tool. All the required data including hazard ratios (HRs), sensitivity (SENS), and specificity (SPEC) were extracted for further analysis, and all analyses were carried out using Stata. Results: In the prognostic part, our initial search of three databases produced 10,548 articles, of which 58 studies were included in the current study. We assessed the correlation of non-coding RNA (ncRNA) expression with different survival outcomes in breast cancer patients: overall survival (OS) (HR = 1.521), disease-free survival (DFS) (HR = 1.33), recurrence-free survival (RFS) (HR = 1.66), progression-free survival (PFS) (HR = 1.71), metastasis-free survival (MFS) (HR = 0.90), and disease-specific survival (DSS) (HR = 0.37). After eliminating low-quality studies, the results did not change significantly. In the diagnostic part, 22 articles and 30 datasets were retrieved from 8,453 articles. The quality of all studies was determined. The bivariate and random-effects models were used to assess the diagnostic value of ncRNAs. The overall area under the curve (AUC) of ncRNAs in differentiated patients is 0.88 (SENS: 80% and SPEC: 82%). There was no difference in the potential of single and combined ncRNAs in differentiated BC patients. However, the overall potential of microRNAs (miRNAs) is higher than that of long non-coding RNAs (lncRNAs). No evidence of publication bias was found in the current study. Nine miRNAs, four lncRNAs, and five gene targets showed significant OS and RFS between normal and cancer patients based on pan-cancer data analysis, demonstrating their potential prognostic value. Conclusion: The present umbrella review showed that ncRNAs, including lncRNAs and miRNAs, can be used as prognostic and diagnostic biomarkers for breast cancer patients, regardless of the sample sources, ethnicity of patients, and subtype of breast cancer.

Potential utility of miRNAs for liquid biopsy in breast cancer

Breast cancer (BC) remains the most prevalent malignancy due to its incidence rate, recurrence, and metastasis in women. Conventional strategies of cancer detection– mammography and tissue biopsy lack the capacity to detect the complete cancer genomic landscape. Besides, they often give false- positive or negative results. The presence of this and other disadvantages such as invasiveness, high-cost, and side effects necessitates developing new strategies to overcome the BC burden. Liquid biopsy (LB) has been brought to the fore owing to its early detection, screening, prognosis, simplicity of the technique, and efficient monitoring. Remarkably, microRNAs (miRNAs)– gene expression regulators seem to play a major role as biomarkers detected in the samples of LB. Particularly, miR-21 and miR-155 among other possible candidates seem to serve as favorable biomarkers in the diagnosis and prognosis of BC. Hence, this review will assess the potential utility of miRNAs as biomarkers and will highlight certain promising candidates for the LB approach in the diagnosis and management of BC that may optimize the patient outcome.

Prognosticating 2-Year Survival Rate of Breast Cancer Patients Through Plasma miRNA-21 and Other Associating Factors

Background

miRNA-21, one of breast cancer (BC) predictive markers, is now gaining cardinal attention from researchers worldwide to evaluate BC patients' survival rate. However, cancer staging, hormonal status, and other BC markers still have to be discussed. We aim to determine the relationship between miRNA-21 and associating factors such as BC staging, other tumor markers, and hormonal status to predict the 2-year survival rate of BC patients.

Methods

We conducted a prospective cohort study on 49 BC patients (26 early stage, 23 advanced stage). Apart from cancer staging, we also examined CEA, Ca15-3, and hormonal status (ER, PR, Her2) and correlated them with miRNA-21 to predict 2-year survival rate. We did bivariate, multivariate, and survival analyses to determine the link between miRNA-21 and those factors to prognosticate on 2-year survival rate.

Results

There are significances between advanced and loco-regional stage (p < 0.001); high and low miRNA-21 (p = 0.002) and CA 15-3 (p = 0.001), and low survival rate in patients with ER/PR-Her2- status (p=0.0015). Cox proportional hazard showed miRNA-21 (Adjusted HR 1.41; 95% CI = 1.205-1.632), cancer stage (Adjusted HR 9.5; 95% CI = 1.378-20.683), and CA15-3 (Adjusted HR 4.64; 95% CI = 1.548-13.931) affected patients' mortality within 2 years.

Conclusion

Low two-year survival rate depends on miRNA-21, cancer stage, CA15-3, and ER/PR-Her2-. Cancer stage is robustly associated with miRNA-21 in predicting 2-year survival rate.

lncRNA GAS5 Sensitizes Breast Cancer Cells to Ionizing Radiation by Inhibiting DNA Repair

Radioresistance of breast cancer is a major reason for therapeutic failure and limits further increases in the dose of radiation due to severe adverse effects. Recently, long noncoding RNAs (lncRNAs) have been shown to regulate cancer proliferation, chemoresistance, and radioresistance. Among these lncRNAs, lncRNA GAS5 expression was shown to be downregulated in breast cancer and related to trastuzumab resistance. However, its role in the radiation response is unclear. In this study, we demonstrated that lncRNA GAS5 expression was reduced in irradiated cells and that overexpression of GAS5 reduced cell viability and promoted cell apoptosis after irradiation. Moreover, overexpression of GAS5 resulted in increased G2/M arrest and unrepaired DNA damage, indicating a radiosensitizing role of GAS5 in breast cancer cells. Finally, we found that a GAS5-interacting miRNA, miR-21, reversed the radiosensitizing effects of GAS5 by inhibiting the apoptotic pathway. In conclusion, we found that lncRNA GAS5 sensitized breast cancer cells to ionizing radiation by inhibiting DNA repair and suppressing miR-21, identifying novel targets for breast cancer radiosensitization.

Breast Cancer-Epidemiology, Risk Factors, Classification, Prognostic Markers, and Current Treatment Strategies-An Updated Review

Simple Summary

Breast cancer is the most common cancer among women. It is estimated that 2.3 million new cases of BC are diagnosed globally each year. Based on mRNA gene expression levels, BC can be divided into molecular subtypes that provide insights into new treatment strategies and patient stratifications that impact the management of BC patients. This review addresses the overview on the BC epidemiology, risk factors, classification with an emphasis on molecular types, prognostic biomarkers, as well as possible treatment modalities.

Abstract

Breast cancer (BC) is the most frequently diagnosed cancer in women worldwide with more than 2 million new cases in 2020. Its incidence and death rates have increased over the last three decades due to the change in risk factor profiles, better cancer registration, and cancer detection. The number of risk factors of BC is significant and includes both the modifiable factors and non-modifiable factors. Currently, about 80% of patients with BC are individuals aged >50. Survival depends on both stage and molecular subtype. Invasive BCs comprise wide spectrum tumors that show a variation concerning their clinical presentation, behavior, and morphology. Based on mRNA gene expression levels, BC can be divided into molecular subtypes (Luminal A, Luminal B, HER2-enriched, and basal-like). The molecular subtypes provide insights into new treatment strategies and patient stratifications that impact the management of BC patients. The eighth edition of TNM classification outlines a new staging system for BC that, in addition to anatomical features, acknowledges biological factors. Treatment of breast cancer is complex and involves a combination of different modalities including surgery, radiotherapy, chemotherapy, hormonal therapy, or biological therapies delivered in diverse sequences.

miR-21 Plays a Dual Role in Tumor Formation and Cytotoxic Response in Breast Tumors

Simple Summary

miR-21 is an oncogenic microRNA that has been associated with breast tumor growth and metastasis in vitro and is also noted to be upregulated by cytotoxic stressors in model systems and in breast cancer patients who have undergone radiation. In the present study, our findings demonstrate the novel role of miR-21 in vivo for breast cancer initiation and metastases, and in sensitizing tumor cells to cytotoxic therapy by upregulating the FAS/FASL signaling pathway.

Abstract

Breast cancer (BrCa) relies on specific microRNAs to drive disease progression. Oncogenic miR-21 is upregulated in many cancers, including BrCa, and is associated with poor survival and treatment resistance. We sought to determine the role of miR-21 in BrCa tumor initiation, progression and treatment response. In a triple-negative BrCa model, radiation exposure increased miR-21 in both primary tumor and metastases. In vitro, miR-21 knockdown decreased survival in all BrCa subtypes in the presence of radiation. The role of miR-21 in BrCa initiation was evaluated by implanting wild-type miR-21 BrCa cells into genetically engineered mouse models where miR-21 was intact, heterozygous or globally ablated. Tumors were unable to grow in the mammary fat pads of miR-21^−/− mice, and grew in ~50% of miR-21^+/− and 100% in miR-21^+/+ mice. The contribution of miR-21 to progression and metastases was tested by crossing miR-21^−/− mice with mice that spontaneously develop BrCa. The global ablation of miR-21 significantly decreased the tumorigenesis and metastases of BrCa, while sensitizing tumors to radio- and chemotherapeutic agents via Fas/FasL-dependent apoptosis. Therefore, targeting miR-21 alone or in combination with various radio or cytotoxic therapies may represent novel and efficacious therapeutic modalities for the future treatment of BrCa patients.

Mitophagy promotes sorafenib resistance through hypoxia-inducible ATAD3A dependent Axis

BACKGROUND

The identification of novel targets for recovering sorafenib resistance is pivotal for Hepatocellular carcinoma (HCC) patients. Mitophagy is the programmed degradation of mitochondria, and is likely involved in drug resistance of cancer cells. Here, we identified hyperactivated mitophagy is essential for sorafenib resistance, and the mitophagy core regulator gene ATAD3A (ATPase family AAA domain containing 3A) was down regulated in hypoxia induced resistant HCC cells. Blocking mitophagy may restore the sorafenib sensitivity of these cells and provide a new treatment strategy for HCC patients.

METHODS

Hypoxia induced sorafenib resistant cancer cells were established by culturing under 1% O2 with increasing drug treatment. RNA sequencing was conducted in transfecting LM3 cells with sh-ATAD3A lentivirus. Subsequent mechanistic studies were performed in HCC cell lines by manipulating ATAD3A expression isogenically where we evaluated drug sensitivity, molecular signaling events. In vivo study, we investigated the combined treatment effect of sorafenib and miR-210-5P antagomir.

RESULTS

We found a hyperactivated mitophagy regulating by ATAD3A-PINK1/PARKIN axis in hypoxia induced sorafenib resistant HCC cells. Gain- and loss- of ATAD3A were related to hypoxia-induced mitophagy and sorafenib resistance. In addition, ATAD3A is a functional target of miR-210-5p and its oncogenic functions are likely mediated by increased miR-210-5P expression. miR-210-5P was upregulated under hypoxia and participated in regulating sorafenib resistance. In vivo xenograft assay showed that miR-210-5P antagomir combined with sorafenib abrogated the tumorigenic effect of ATAD3A down-regulation in mice.

CONCLUSIONS

Loss of ATAD3A hyperactivates mitophagy which is a core event in hypoxia induced sorafenib resistance in HCC cells. Targeting miR-210-5P-ATAD3A axis is a novel therapeutic target for sorafenib-resistant HCC.

MicroRNAs: potential biomarkers for diagnosis and prognosis of different cancers

A thorough understanding of the tumor environment and underlying genetic factors helps in the better formulation of cancer management strategies. Availability of efficient diagnostic and prognostic biomarkers facilitates early detection and progression of the disease. MicroRNAs affect different biological processes participating in tumorigenesis through regulation of their target genes. An expanding list of unique RNAs and understanding of their regulatory role has opened up a new field in cancer research. Based on a comprehensive literature search, we identified 728 miRNAs dysregulated in sixteen cancer types namely bladder cancer (BC), breast cancer (BrC), cervical cancer (CC), colorectal cancer (CRC), esophageal cancer (EC), endometrial cancer (EnC), gastric cancer (GC), hepatocellular cancer (HCC), head and neck squamous cell cancer (HNSCC), lung cancer (LC), ovarian cancer (OC), pancreatic cancer (PC), prostate cancer (PrC), renal cell cancer (RCC), skin cancer (SC), and thyroid cancer (TC). Expression of 43 miRNAs was either upregulated or downregulated in six or more of these cancers. Finally, seven miRNAs namely mir-18a, mir-21, mir-143/145, mir-210, mir-218, mir-221, showing maximum dysregulation, either up- or down-regulation in the majority of cancers, were selected for a detailed presentation of their expression and evaluation of their potential as biomarkers in the diagnosis and prognosis of different cancers.

miR‑589‑3p sponged by the lncRNA TINCR inhibits the proliferation, migration and invasion and promotes the apoptosis of breast cancer cells by suppressing the Akt pathway via IGF1R

The long non-coding (lnc)RNA named tissue differentiation inducing non-protein coding RNA (TINCR) is a tumor marker that has not been studied in breast cancer. The present study aimed to investigate the TINCR-targeting micro (mi)RNAs and the regulatory mechanisms of TINCR in breast cancer. Following prediction by TargetScan and confirmation by dual-luciferase reporter assay, TINCR was demonstrated to be a target gene for miR-589-3p. The expression of TINCR and miR-589-3p in breast cancer and adjacent tissues was detected by reverse transcription-quantitative (RT-q)PCR, and the correlation between TINCR and miR-589-3p expression was determined by using Spearman correlation analysis. The 5-years survival was analyzed in patients with breast cancer according to TINCR expression (high or low). The effects of TINCR and miR-589-3p on the proliferation, apoptosis, migratory and invasive abilities of some breast cancer cell lines were detected by MTT assay, flow cytometry, wound healing assay and Transwell assay. The target gene of miR-589-3p was predicted and verified by TargetScan and dual-luciferase reporter assay, and the mechanism of miR-589-3p involvement in breast cancer cells was explored by overexpression or downregulation of miR-589-3p in breast cancer cells. RT-qPCR and western blotting were used to determine the expression of the insulin-like growth factor 1 receptor (IGF1R)/AKT pathway-related genes. The results demonstrated that TINCR expression level was negatively correlated with miR-589-3p expression level in breast cancer tissues and that patients with high expression of TINCR presented with lower survival rates. In addition, TINCR overexpression in cancer cells inhibited miR-589-3p expression, and cell transfection with miR-589-3p mimic partially reversed the effect of TINCR overexpression on the promotion of cancer cell proliferation, migration and invasion, and on the inhibition of cancer cell apoptosis. Furthermore, IGF1R, which is a target gene of miR-589-3p, increased cancer cell proliferation, migration and invasion and inhibited cancer cell apoptosis; however, these effects were partially reversed by miR-589-3p mimic. Furthermore, the results demonstrated that miR-589-3p mimic could downregulate the protein expression of IGF1R and p-AKT. In addition, TINCR overexpression downregulated miR-589-3p expression level. miR-589-3p partially reversed the effects of TINCR overexpression on cancer cell proliferation, migration and invasion, and inhibited cancer cell apoptosis by inhibiting the IGF1R-Akt pathway. The results from the present study demonstrated that TINCR may sponge miR-589-3p in order to inhibit IGF1R-Akt pathway activation in breast cancer cells, promoting therefore cancer cell proliferation, migration and invasion.

Progress in triple negative breast carcinoma pathophysiology: Potential therapeutic targets

Triple-negative breast carcinoma (TNBC) is a subtype of breast carcinoma defined by negativity for estrogen receptor (ER) or progesterone receptor (PR) by immunohistochemical analysis and negativity for human epidermal growth factor receptor (Her2) by immunohistochemistry or in situ hybridization. TNBC is clinically marked by its high aggressiveness, particularly poor outcomes including a low survival rate, and the lack of specific and effective treatments. Therefore, new potential targets for the treatment of TNBC must be identified. This review summarizes recent evidence supporting novel targets and possible therapeutic regimens in the treatment of TNBC.

Identification of miRNA-Based Signature as a Novel Potential Prognostic Biomarker in Patients with Breast Cancer

To identify the novel, noninvasive biomarkers to assess the outcome and prognosis of breast cancer (BC), patients with high sensitivity and specificity are greatly desired. Herein, the miRNA expression profile and matched clinical features of BC patients were extracted from The Cancer Genome Atlas (TCGA) database. The preliminary candidates were screened out by the univariate Cox regression test. Then, with the help of LASSO Cox regression analysis, the hsa-let-7b, hsa-mir-101-2, hsa-mir-135a-2, hsa-mir-22, hsa-mir-30a, hsa-mir-31, hsa-mir-3130-1, hsa-mir-320b-1, hsa-mir-3678, hsa-mir-4662a, hsa-mir-4772, hsa-mir-493, hsa-mir-556, hsa-mir-652, hsa-mir-6733, hsa-mir-874, and hsa-mir-9-3 were selected to construct the overall survival (OS) predicting signature, while the hsa-mir-130a, hsa-mir-204, hsa-mir-217, hsa-mir-223, hsa-mir-24-2, hsa-mir-29b-1, hsa-mir-363, hsa-mir-5001, hsa-mir-514a-1, hsa-mir-624, hsa-mir-639, hsa-mir-659, and hsa-mir-6892 were adopted to establish the recurrence-free survival (RFS) predicting signature. Referring to the median risk scores generated by the OS and RFS formulas, respectively, subgroup patients with high risk were strongly related to a poor OS and RFS revealed by Kaplan-Meier (K-M) plots. Meanwhile, receiver operating curve (ROC) analysis validated the accuracy and stability of these two signatures. When stratified by clinical features, such as tumor stage, age, and molecular subtypes, we found that the miRNA-based OS and RFS classifiers were still significant in predicting OS/RFS and showed the best predictive values than any other features. Besides, functional prediction analyses showed that these targeted genes of the enrolled miRNAs were enriched in cancer-associated pathways, such as MAPK/RTK, Ras, and PI3K-Akt signaling pathways. In summary, our observations demonstrate that the novel miRNA-based OS and RFS signatures are independent prognostic indicators for BC patients and worthy to be validated by further prospective studies.

Prognostic role of microRNAs in breast cancer: A systematic review

MicroRNAs (miRNAs) have been found to play an important role in breast cancer, functioning either as potential oncogenes or tumor suppressor genes, but their role in the prognosis of patients remains unclear. The aim of the present review study is to highlight recent preclinical and clinical studies performed on both circulating and tissue-specific miRNAs and their potential role as prognostic markers in breast cancer. We systematically searched the PubMed database to explore the prognostic value of miRNAs in breast cancer. After performing the literature search and review, 117 eligible studies were identified. We found that 110 aberrantly expressed miRNAs have been associated with prognosis in breast cancer. In conclusion, the collective data presented in this review indicate that miRNAs could serve as novel prognostic tools in breast cancer, while the clinical application of these findings has yet to be verified.

Clinical significance of aberrant microRNAs expression in predicting disease relapse/refractoriness to treatment in diffuse large B-cell lymphoma: A meta-analysis

The clinical significance of aberrantly expressed microRNAs in predicting treatment response to chemotherapy in diffuse large B-cell lymphoma patients (DLBCL) remains uncertain. Feasibility of microRNA testing to predict treatment outcome was evaluated. Twenty-two types of aberrantly expressed microRNAs were associated with poor treatment response; pooled hazard ratio (HR) was 2.14 [95%CI:1.78-2.57, P < 0.00001]. DLBCL patients with aberrant expression of miR-155, miR-17/92 clusters, miR-21, miR-224, or miR-146b-5p had a higher risk of treatment resistance or shorter period of disease relapse/progression free survival, with HR = 2.71 (95%CI:1.66-4.42, P < 0.0001), HR = 2.70 (95%CI:1.50-4.85, P = 0.0010), HR = 2.20 (95%CI:1.31-3.69, P = 0.003), HR = 2.07 (95%CI:1.50-2.86, P < 0.00001), HR = 2.26 (95%CI:1.40-3.65, P = 0.0009), respectively. The association between aberrant expression of microRNAs and treatment response appears to be stronger in formalin-fixed-paraffin-embedded tissue (HR = 2.41, 95%CI:1.79-3.25, P < 0.00001) than in fresh-frozen samples (HR = 1.94, 95%CI: 1.22-3.08, P = 0.005) and peripheral blood samples (HR = 1.94, 95%CI:1.53-2.46, P < 0.00001). Mir-155, miR-17/92 clusters, miR-21, miR-224, and mir-146b-5p have value in predicting treatment response to chemotherapy in DLBCL.

miR-210-3p regulates the proliferation and apoptosis of non-small cell lung cancer cells by targeting SIN3A

Previous studies have indicated that microRNA (miR)-210-3p is upregulated in NSCLC, however, the specific mechanism underlying the role of miR-210-3p in NSCLC pathogenesis requires further investigation. The aim of the present study was to explore the roles of miR-210-3p in NSCLC and the associated mechanisms. A total of 30 NSCLC tissues and paired adjacent normal tissues were collected for study. Reverse transcription-quantitative polymerase chain reaction was performed to compare the expression of miR-210-3p in the 30 paired cancerous and adjacent normal tissues. Additionally, the expression of miR-210-3p in different NSCLC lines and normal human lung epithelial cell line BEAS-2B were also compared. Furthermore, A549 and H1299 NSCLC cells were cultured and transfected with miR-210-3p inhibitors, and MTT and propidium iodide/annexin V assays were performed to investigate the effects of miR-210-3p inhibition on the proliferation and apoptosis of the cells. RT-qPCR and western blot analyses were also performed to determine the effects of miR-210-3p on the expression levels of SIN3A, B-cell lymphoma 2 (Bcl-2) and Caspase-3. Finally, a reverse experiment was conducted by transfecting A549 cells with miR-210-3p inhibitor and SIN3A small interfering (si)RNA, and a dual-luciferase reporter assay was performed to confirm that SIN3A is a direct target of miR-210-3p. It was observed that miR-210-3p was significantly upregulated in NSCLC tissues compared with the levels in the adjacent normal tissues, and that the expression of miR-210-3p in patients with NSCLC was negatively correlated with the expression of SIN3A in NSCLC tissue. miR-210-3p was also significantly upregulated in different NSCLC cell lines compared with the levels in BEAS-2B cells. The transient downregulation of miR-210-3p in A549 cells led to a significant suppression of cell proliferation and markedly increased cell apoptosis, as well as increased the expression of SIN3A and Caspase-3 and decreased the expression of Bcl-2. On the other hand, co-transfection of miR-210-3p inhibitor and SIN3A siRNA partially blocked miR-210-3p inhibitor-induced pro-apoptotic effects. The results of the dual-luciferase reporter assay demonstrated that SIN3A is a direct target of miR-210-3p. Collectively, these findings indicate that can regulate the proliferation and apoptosis of NSCLC cells by targeting SIN3A. These results suggest that miR-210-3p has the potential to become a novel therapeutic target for the treatment of NSCLC.

Aberrant miRNAs expressed in HER-2 negative breast cancers patient

Background

Breast cancer is a highly heterogeneous pathology, exhibiting a number of subtypes commonly associated with a poor outcome. Due to their high stability, microRNAs are often regarded as non-invasive cancer biomarkers, having an expression pattern specific for their ‘cell of origin’.

Method

Triple negative breast cancer (TNBC: ER-, PR-, Her-2-) and double positive breast cancer (DPBC: ER+, PR+, Her-2) miRNA expression patterns were obtained by analysis of the TCGA (The Cancer Genome Atlas) data, followed by PCR-array analysis on plasma samples from 20 TNBC patients, 14 DPBC patients and 11 controls.

Results

Three downregulated and nine upregulated miRNAs were obtained from the TNBC analysis. Five overexpressed miRNAs were identified in the DPBC group. Four of the dysregulated miRNAs (miR-10a, miR-125b, miR-210 and miR-489) were common for both groups. The cluster miR-17-92 (miR-17, miR-20a, miR-20b, and miR-93), along with miR-130, miR-22 and miR-29a/c, were found to differentiate between TNBC and DPBC. A panel of five transcripts (miR-10a, miR-125, miR-193b, miR-200b and miR-489) was validated in a new set of plasma samples. The overlapping of TCGA and plasma profiling data revealed miR-200b, miR-200c, miR-210 and miR-29c as common signature. MiR-200b was validated on additional normal and tumor tissue samples. The expression level of this transcript from the TCGA data was correlated with lung and bone metastatic genes.

Conclusion

The miR-200b presents a great potential for the future advancements in the diagnostic/prognostic and therapeutic approach of TNBC, along with other coding or non-coding transcripts. However, this needs to be further integrated in a regulatory network that acts in conjunction with other markers that affect the patients’ prognosis or response to therapy.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0920-2) contains supplementary material, which is available to authorized users.

The correlation of circulating pro-angiogenic miRNAs' expressions with disease risk, clinicopathological features, and survival profiles in gastric cancer

This study aimed to explore the correlation of circulating pro‐angiogenic miRNAs’ expressions with risk, clinicopathological features, and survival profiles in gastric cancer (GC). Three hundred and thirty‐three GC patients underwent radical resection and 117 health controls (HCs) were recruited for this study. Plasma samples were obtained from GC patients before the operation and from HCs after enrollment. Fourteen pro‐angiogenic miRNAs were asseassed by quantitative polymerase chain reaction (qPCR). Disease‐free survival (DFS) and overall survival (OS) of GC patients were calculated and the median follow‐up duration was 36.0 months. Seven out of 14 pro‐angiogenic miRNAs including let‐7f, miR‐17‐5p, miR‐18a, miR‐19b‐1, miR‐20a, miR‐210, and miR‐296 were observed to be elevated in GC patients compared with HCs. MiR‐18a, miR‐20a, and miR‐210 disclosed good predictive values of GC risk. Six pro‐angiogenic miRNAs including miR‐17‐5p, miR‐92a, miR‐210, miR‐20a, miR‐18a, and miR‐296 expressions were positively while 1 pro‐angiogenic miRNA (miR‐130a) was negatively correlated with tumor malignancy degree in GC patients. K‐M curve disclosed that 5 pro‐angiogenic miRNAs including miR‐17‐5p, miR‐18a, miR‐20a, miR‐92a, and miR‐210 correlated with worse DFS, while 4 pro‐angiogenic miRNAs including miR‐17‐5p, miR‐18a, miR‐20a, and miR‐210 associated with shorter OS. Further multivariate Cox's analysis revealed that miR‐17‐5p, miR‐18a, miR‐20a, and miR‐210 were independent predictive factors for unfavorable DFS and OS. In conclusion, circulating pro‐angiogenic miRNAs could serve as novel noninvasive biomarkers for disease risk and malignancy degree, and miR‐17‐5p, miR‐18a, miR‐20a, and miR‐210 are independent factors predicting poor prognosis in GC patients.

MiR-142 inhibits the development of cervical cancer by targeting HMGB1

It has been reported that miRNAs is deregulated in diverse human cancers, involving human cervical cancer. However, the clinical significances and potential mechanisms of miR-142 in the development and progression of cervical cancer were not elucidated completely till now. In this study, we found that the expression of miR- 142 was obviously down-regulated in human cervical cancer tissues and a panel of cell lines. According to statistics, the expression of miR-142 was negatively related to advanced FIGO stage and lymphatic metastasis (p < 0.001). Furthermore, our functional analysis revealed the overexpression of miR-142 affected cell proliferation and invasiveness, and enhanced cell apoptosis in representative SiHa and HeLa cells. Based on the molecular level, our findings showed the 3′ untranslated region (3′-UTR) of high-mobility group box 1 protein (HMGB1) was a direct target of miR-142, and determined an inverse correlation with the expression of miR-142. Ectopic expression of HMGB1 could attenuate the inhibitory impact of miR-142 on the proliferation and invasiveness of cervical cancer cells. In conclusion, the present work suggested that miR-142 affects cervical cancer cell proliferation and invasiveness, and enhances cell apoptosis via directly targeting the expression of HMGB1, and these findings may lay a novel foundation for the promising therapy target of cervical cancer.

MicroRNAs in Breast Cancer: Diagnostic and Therapeutic Potential

MicroRNAs (miRNAs) are a large family of small, approximately 20-22 nucleotide, noncoding RNAs that regulate the expression of target genes, at the post-transcriptional level. miRNAs are involved in virtually diverse biological processes and play crucial roles in cellular processes, such as cell differentiation, proliferation, and apoptosis. Accumulating lines of evidence have indicated that miRNAs play important roles in the maintenance of biological homeostasis and that aberrant expression levels of miRNAs are associated with the onset of many diseases, including cancer. It is possible that the diverse roles that miRNAs play, have potential to provide valuable information in a clinical setting, demonstrating the potential to act as both screening tools for the stratification of high-risk patients, while informing the treatment decision-making process. Increasing evidence suggests that some miRNAs may even provide assistance in the diagnosis of patients with breast cancer. In addition, miRNAs may themselves be considered therapeutic targets, with inhibition or reintroduction of a particular miRNA capable of inducing a response in-vivo. This chapter discusses the role of miRNAs as oncogenes and tumor suppressors in breast cancer development and metastasis . It focuses on miRNAs that have prognostic, diagnostic, or predictive potential in breast cancer as well as the possible challenges in the translation of such observations to the clinic.

Implications of dietary ω-3 and ω-6 polyunsaturated fatty acids in breast cancer

Breast cancer represents one of the most common forms of cancer in women worldwide, with an increase in the number of newly diagnosed patients in the last decade. The role of fatty acids, particularly of a diet rich in ω-3 and ω-6 polyunsaturated fatty acids (PUFAs), in breast cancer development is not fully understood and remains controversial due to their complex mechanism of action. However, a large number of animal models and cell culture studies have demonstrated that high levels of ω-3 PUFAs have an inhibitory role in the development and progression of breast cancer, compared to ω-6 PUFAs. The present review focused on recent studies regarding the correlation between dietary PUFAs and breast cancer development, and aimed to emphasize the main molecular mechanisms involved in the modification of cell membrane structure and function, modulation of signal transduction pathways, gene expression regulation, and antiangiogenic and antimetastatic effects. Furthermore, the anticancer role of ω-3 PUFAs through the modulation of microRNA expression levels was also reviewed.

Candidate miRNAs in human breast cancer biomarkers: a systematic review

BACKGROUND

Breast cancer (BC) is the most prevalent cancer and the main cause of cancer deaths among females around the world. For early diagnosis of BC, there would be an immediate and essential requirement to search for sensitive biomarkers.

METHODS

To identify candidate miRNA biomarkers for BC, we performed a general systematic review regarding the published miRNA profiling researches comparing miRNA expression level between BC and normal tissues. A miRNA ranking system was selected, which considered frequency of comparisons in direction and agreement of differential expression.

RESULTS

We determined that two miRNAs (mir-21 and miR-210) were upregulated consistently and six miRNAs (miR-145, miR-139-5p, miR-195, miR-99a, miR-497 and miR-205) were downregulated consistently in at least three studies. MiR-21 as the most consistently reported miRNA was upregulated in six profiling studies.

CONCLUSIONS

Although these miRNAs require being validated and further investigated, they could be potential candidates for BC miRNA biomarkers and used for early prognosis or diagnosis.

Pathologic diagnosis of breast cancer patients: evolution of the traditional clinical-pathologic paradigm toward "precision" cancer therapy

We present an updated account of breast cancer treatment and of progress toward "precision" cancer therapy; we focus on new developments in diagnostic molecular pathology and breast cancer that have emerged during the past 2 years. Increasing awareness of new prognostic and predictive methodologies, and introduction of next generation sequencing has increased understanding of both tumor biology and clinical behavior, which offers the possibility of more appropriate therapeutic choices. It remains unclear which of these testing methodologies provides the most informative and cost-effective actionable results for predictive and prognostic pathology. It is likely, however, that an integrated "step-wise" approach that uses the traditional clinical-pathologic paradigms coordinated with molecular characterization of breast tumor tissue, will offer the most comprehensive and cost-effective options for individualized, "precision" therapy for patients with breast cancer.

Downregulation of miRNA-141 in breast cancer cells is associated with cell migration and invasion: involvement of ANP32E targeting

MicroRNAs (miRNAs) regulate many cellular activities, including cancer development, progression, and metastasis. Some miRNAs are involved in breast cancer (BC) migration and invasion, thus affect patients’ prognosis. Microarray analysis was performed to compare miRNA expression in BC tissues, and results confirmed by qPCR. BC cell migration and invasion were studied in vitro with MDA‐MB‐231 cells using microplate transwell assays. miRNA targeting was investigated using luciferase assays, qPCR, and Western blot analysis in cells with overexpression of miRNA mimics. Knockdown of miRNA targets was performed using target siRNA lentiviral infection. Results show that microRNA‐141 (miR‐141) was downregulated in breast cancer tumor tissues compared with matched surrounding tissues. Downregulation of miR‐141 expression correlated with tumor stage, lymph node involvement, and expressions of PCNA, Ki67, and HER2. Overexpression of miR‐141 inhibited BC cell proliferation, migration, and invasion in vitro. ANP32E gene was selected as one putative target for further studies based on results from in silico analysis. Results from a dual‐luciferase reporter system suggested ANP32E as a direct target of miR‐141. Overexpression of miR‐141 downregulated ANP32E expression at both mRNA and protein levels in BC cells. Knockdown of ANP32E inhibited BC cell proliferation, migration, and invasion in vitro, mimicking the effect of the overexpression of miR‐141. Our study revealed important roles miR‐141 plays in BC growth and metastasis. Moreover, for the first time, we identified ANP32E as one of the miR‐141 targets, and demonstrated its involvement in the regulation of cell proliferation, migration, and invasion.

Identification of Biomarkers for Breast Cancer Using Databases

Breast cancer is one of the major causes of cancer death in women. Many studies have sought to identify specific molecules involved in breast cancer and understand their characteristics. Many biomarkers which are easily measurable, dependable, and inexpensive, with a high sensitivity and specificity have been identified. The rapidly increasing technology development and availability of epigenetic informations play critical roles in cancer. The accumulated data have been collected, stored, and analyzed in various types of databases. It is important to acknowledge useful and available data and retrieve them from databases. Nowadays, many researches utilize the databases, including The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), Surveillance, Epidemiology and End Results (SEER), and Embase, to find useful informations on biomarkers for breast cancer. This review summarizes the current databases which have been utilized for identification of biomarkers for breast cancer. The information provided by this review would be beneficial to seeking appropriate strategies for diagnosis and treatment of breast cancer.

Positive expression of miR-361-5p indicates better prognosis for breast cancer patients

BACKGROUND

MicroRNA-361-5p (miR-361-5p) has been reported to be tumor suppressor in colorectal, gastric and prostate cancer, but as an oncogene in cervical cancer. No previous research has focused on the expression of miR-361-5p and its exact prognostic role in breast cancer (BC).

METHODS

In this study, a tissue microarray (TMA)-based miRNA detection in situ hybridization (ISH) with LNA probe was used to detect miR-361-5p expression in 375 BC tissue. The expression level of miR-361-5p in BC and its potential prognostic value was investigated.

RESULTS

Positive miR-361-5p staining was observed in 78.7% (N=295; 78.7% positive, 21.3% negative) in the 375 cases. The clinical outcome of patients with positive miR-361-5p expression [median disease-free survival (DFS) time 95.52 months] was significantly better than that of patients (median DFS time 82.33 months) with negative miR-361-5p expression (P=0.002). Moreover, the prognostic value of miR-361-5p was most significant among patients with triple-negative breast cancer (TNBC) for DFS (P=0.004).

CONCLUSIONS

These results indicated that miR-361-5p expression is an independent predictive factor for better prognosis in BC.

MicroRNA-21 activation of ERK signaling via PTEN is involved in arsenite-induced autophagy in human hepatic L-02 cells

Autophagy, an evolutionarily conserved cellular process, has diverse physiological and pathological roles in biological functions. Whether autophagy is induced by arsenite, a well-established human carcinogen, and the molecular mechanisms involved, remain to be established. Further, microRNAs (miRNAs) act as regulators in various cancers, but how miRNAs regulate autophagy remains largely unexplored. We have found that, in human hepatic epithelial (L-02) cells, arsenite increases levels of autophagy-related proteins in a concentration- and time-dependent manner and elevates the number of autophagic vacuoles (AVs). Arsenite also activates the ERK pathway in a dose- and time-dependent manner. In L-02 cells exposed to arsenite, microRNA-21 (miRNA-21) is over-expressed, and its target proteins, PTEN, PDCD4, and Spry1, are decreased. Moreover, inhibition of miR-21 increases levels of PTEN, and reduces levels of Beclin 1 and LC3 II/I, indicating that miR-21 is involved in arsenite-induced autophagy. In addition, ectopic expression of PTEN blocks the effect of miR-21 on the arsenite-induced autophagy and decreases p-ERK levels. Also, ERK promotes the autophagy induced by arsenite. In sum, upon exposure of cells to arsenite, over-expression of miR-21 activates ERK through PTEN, factors that participate in arsenite-induced autophagy. This link, mediated through miRNAs, establishes a mechanism for the development of autophagy that is associated with arsenic toxicity. Such information contributes to an understanding of the liver toxicity caused by arsenite.

Exploration of the regulatory effect of miR-21 on breast cancer cell line proliferation and invasion as well as the downstream target genes

OBJECTIVE

To study the regulatory effects of miR-21 on breast cancer cell line proliferation and invasion as well as the downstream target genes.

METHODS

Breast cancer cell lines MCF-7 were cultured and transfected with miR-21 mimics and the corresponding negative control mimics (NC mimics), and then MTS kits were used to detect cell viability. Transwell experiment was used to detect cell invasion ability, and fluorescence quantitative PCR was used to detect the expression of proliferation and invasion-related genes in cells.

RESULTS

24 h after transfection of miR-21 mimics and NC mimics, cell OD value and the number of invasive cells of miR-21 group were significantly higher than those of NC group, and mRNA contents of PDCD-4, FasL, PTEN, RhoB, Maspin, TIMP3 and RECK in cells were significantly lower than those of NC group.

CONCLUSION

miR-21 can promote the proliferation and invasion of breast cancer cell lines, and its downstream target genes include PDCD-4, FasL, PTEN, RhoB, Maspin, TIMP3 and RECK.