miRNA expression patterns in chemoresistant breast cancer tissues

The role of miR-765 in human cancers

MicroRNAs, a collection of short noncoding RNAs, are promising biomarkers for identifying cancer in its early stages and tracking the effectiveness of treatment. This is due to their critical role in regulating gene expression and other vital biological functions via cell-level epigenetic mechanisms. This review brings together data on the molecular and clinical effects of miR-765 on different types of cancer. Significant variation in miR-765 levels has been observed in a variety of cancer types, suggesting that it could have an oncogene or tumor suppressor role. A number of pathways, including PLP2/Notch, VEGFA/Akt1, PDX1, KLK4, RUNX2, DPF3, EMP3, APE1, ERK/EMT axis, and others, are impacted by the inclusion of miR-765 in their analysis. MiR-765 is an essential biomarker that shows promise as a diagnostic tool for various types of cancer. The latest research has identified them as reliable predictive markers for detecting tumor development at an early stage. Based on our study, miR-765 shows promising potential as a biomarker for prognosis in multiple types of cancer. Specifically, we suggest that miR-765 could be an early detection marker for tumor development, progression, and metastasis.

The Overexpressed MicroRNAs miRs-182, 155, 493, 454, and U6 snRNA and Underexpressed let-7c, miR-328, and miR-451a as Potential Biomarkers in Invasive Breast Cancer and Their Clinicopathological Significance

INTRODUCTION

Breast cancer comprises the leading cause of cancer-related death in women. MicroRNAs (miRNAs) have emerged as important factors with concern to carcinogenesis and have potential for use as biomarkers.

METHODS

This study provides a comprehensive evaluation of the microRNA expression in invasive breast carcinoma of no special type tissues compared with benign tissues via large-scale screening and the candidate-specific validation of 15 miRNAs and U6 snRNA applying qPCR and the examination of clinicopathological data.

RESULTS

Of the six downregulated miRNAs, let-7c was identified as the most promising miRNA biomarker and its lower expression was linked with Ki-67 positivity, luminal B versus luminal A samples, multifocality, lymph node metastasis, and inferior PFS. Of the 9 upregulated sncRNAs, the data on U6 snRNA, miR-493 and miR-454 highlighted their potential oncogenic functions. An elevated U6 snRNA expression was associated with the tumor grade, Ki-67 positivity, luminal B versus A samples, lymph node metastasis, and worsened PFS (and OS) outcomes. An elevated miR-454 expression was detected in higher grades, Ki-67 positive and luminal B versus A samples. Higher miR-493 levels were noted for the tumor stage (and grade) and worse patient outcomes (PFS, OS). The data also suggested that miR-451a and miR-328 may have tumor suppressor roles, and miR-182 and miR-200c pro-oncogenic functions, while the remaining sncRNAs did not evince any significant associations.

CONCLUSION

We showed particular microRNAs and U6 snRNA as differentially expressed between tumors and benign tissues and associated with clinicopathological parameters, thus potentially corresponding with important roles in breast carcinogenesis. Their importance should be further investigated and evaluated in follow-up studies to reveal their potential in clinical practice.

Advances in Diet and Physical Activity in Breast Cancer Prevention and Treatment

There is currently a growing interest in diets and physical activity patterns that may be beneficial in preventing and treating breast cancer (BC). Mounting evidence indicates that indeed, the so-called Mediterranean diet (MedDiet) and regular physical activity likely both help reduce the risk of developing BC. For those who have already received a BC diagnosis, these interventions may decrease the risk of tumor recurrence after treatment and improve quality of life. Studies also show the potential of other dietary interventions, including fasting or modified fasting, calorie restriction, ketogenic diets, and vegan or plant-based diets, to enhance the efficacy of BC therapies. In this review article, we discuss the biological rationale for utilizing these dietary interventions and physical activity in BC prevention and treatment. We highlight published and ongoing clinical studies that have applied these lifestyle interventions to BC patients. This review offers valuable insights into the potential application of these dietary interventions and physical activity as complimentary therapies in BC management.

Candidate Oligo Therapeutic Target, miR-330-3p, Induces Tamoxifen Resistance in Estrogen Receptor-Positive Breast Cancer Cells via HDAC4

Tamoxifen is a drug used for treating breast cancer (BC), especially for individuals diagnosed with estrogen receptor-positive (ER+) BC. Its prolonged use could reduce the risk of recurrence and significantly lengthen the survival rate of BC patients. However, an increasing number of patients developed resistance to tamoxifen treatment, which reduced therapeutic efficiency and caused substandard prognosis. Therefore, the exploration of the molecular processes involved in tamoxifen resistance (TR) is urgently required. This investigation aimed to elucidate the relationship of microRNA-330 (miR-330-3p) with the TR of BC. There is little information on miR-330-3p's link with drug-resistant BC, although it is well known to regulate cell proliferation and apoptosis. Primarily, miR-330-3p expression in parental BC (MCF7/T47D), TR (MCF7-TR), and T47D/TR cell lines was detected by qRT-PCR. Then, the impact of miR-330-3p on the TR of BC cells was assessed by a cell proliferation assay. Lastly, dual-luciferase reporter, qRT-PCR, and western blot assessments were carried out to identify histone deacetylase 4 (HDAC4) as the potential miR-330-3p target gene. The data indicated that miRNA-330 was overexpressed in TR ER+ BC cells and its overexpression could induce TR. Furthermore, miRNA-330 could also reduce the expression of HDAC4, which is closely linked to TR, and overexpression of HDAC4 could reverse miRNA-330-induced drug resistance. In summary, miR-330-3p could induce TR of ER+ BC cells by downregulating HDAC4 expression, which might be a novel marker of TR and a possible treatment target against BC patients who are tamoxifen-resistant.

Circular RNA hsa_circ_0012673 Promotes Breast Cancer Progression via miR-576-3p/SOX4 Axis

Circular RNAs (circRNAs) have been reported to exert critical roles in human cancers. In this study, we investigated the role and molecular mechanism of hsa_circ_0012673 in breast cancer. Herein, we found that the expression of hsa_circ_0012673 was upregulated in breast cancer tissues and cell lines. Knockdown of hsa_circ_0012673 using RNA interference technique suppressed the proliferation, migration, and invasion of breast cancer cells. Mechanistically, hsa_circ_0012673 sponged miR-576-3p to stabilize SRY-box transcription factor 4 (SOX4), and thereby facilitating breast cancer cell proliferation, migration and invasion. Collectively, our study identified the oncogenic properties of hsa_circ_0012673/miR-576-3p/SOX4 axis in breast cancer, providing potential and exploitable diagnostic and therapeutic molecules for breast cancer.

The Role of miR-375-3p, miR-210-3p and Let-7e-5p in the Pathological Response of Breast Cancer Patients to Neoadjuvant Therapy

Background and Objectives: Prediction of response to therapy remains a continuing challenge in treating breast cancer, especially for identifying molecular tissue markers that best characterize resistant tumours. Microribonucleic acids (miRNA), known as master modulators of tumour phenotype, could be helpful candidates for predicting drug resistance. We aimed to assess the association of miR-375-3p, miR-210-3p and let-7e-5p in breast cancer tissues with pathological response to neoadjuvant therapy (NAT) and clinicopathological data. Material and methods: Sixty female patients diagnosed with invasive breast cancer at The Oncology Institute “Ion Chiricuță”, Cluj-Napoca, Romania (IOCN) were included in this study. Before patients received any treatment, fresh breast tissue biopsies were collected through core biopsy under echographic guidance and processed for total RNA extraction and miRNA quantification. The Cancer Genome Atlas Breast Invasive Carcinoma (TCGA-BRCA) database was used as an independent external validation cohort. Results: miR-375-3p expression was associated with more differentiated tumours, hormone receptor presence and lymphatic invasion. According to the Miller–Payne system, a higher miR-375-3p expression was calculated for patients that presented with intermediate versus (vs.) no pathological response. Higher miR-210-3p expression was associated with an improved response to NAT in both Miller–Payne and RCB evaluation systems. Several druggable mRNA targets were correlated with miR-375-3p and miR-210-3p expression, with upstream analysis using the IPA knowledge base revealing a list of possible chemical and biological targeting drugs. Regarding let-7e-5p, no significant association was noticed with any of the analysed clinicopathological data. Conclusions: Our results suggest that tumours with higher levels of miR-375-3p are more sensitive to neoadjuvant therapy compared to resistant tumours and that higher miR-210-3p expression in responsive tumours could indicate an excellent pathological response.

Integrated Multi-Omics Analysis Model to Identify Biomarkers Associated With Prognosis of Breast Cancer

Background

With the rapid development and wide application of high-throughput sequencing technology, biomedical research has entered the era of large-scale omics data. We aim to identify genes associated with breast cancer prognosis by integrating multi-omics data.

Method

Gene-gene interactions were taken into account, and we applied two differential network methods JDINAC and LGCDG to identify differential genes. The patients were divided into case and control groups according to their survival time. The TCGA and METABRIC database were used as the training and validation set respectively.

Result

In the TCGA dataset, C11orf1, OLA1, RPL31, SPDL1 and IL33 were identified to be associated with prognosis of breast cancer. In the METABRIC database, ZNF273, ZBTB37, TRIM52, TSGA10, ZNF727, TRAF2, TSPAN17, USP28 and ZNF519 were identified as hub genes. In addition, RPL31, TMEM163 and ZNF273 were screened out in both datasets. GO enrichment analysis shows that most of these hub genes were involved in zinc ion binding.

Conclusion

In this study, a total of 15 hub genes associated with long-term survival of breast cancer were identified, which can promote understanding of the molecular mechanism of breast cancer and provide new insight into clinical research and treatment.

Overexpression of microRNA-145 enhanced docetaxel sensitivity in breast cancer cells via inactivation of protein kinase B gamma-mediated phosphoinositide 3-kinase -protein kinase B pathway

Chemoresistance is a major challenge for the treatment of breast cancer (BC). Previous studies showed that miR-145 level decreases in chemoresistant BC tissues. Nevertheless, the biological function of miR-145 on docetaxel resistance of BC cells remains unclear, which is what our research attempted to clarify. RT-qPCR analyzed miR-145 level, and cell viability and colony formation assays assessed the impact of miR-145 on docetaxel resistance. Molecular mechanisms of miR-145-mediated docetaxel sensitivity were examined by Luciferase reporter assay and Western Blot assessed the function of AKT3 and PI3K/AKT signaling. Our research found that miR-145 expression presented significant downregulation in docetaxel-resistant BC cells. Meanwhile, miR-145 overexpression facilitated the docetaxel sensitivity of BC cells in vivo and in vitro, while the miR-145 inhibitor decreased the sensitivity of BC cells to docetaxel. We also observed that miR-145 inhibited docetaxel resistance mainly via downregulation of the AKT3 expression and further inhibited PI3K/AKT pathway. To conclude, this research provides a novel strategy for improving chemosensitivity through the newly identified miR-145-AKT3/PI3K-AKT signaling pathway in BC.

Analysis of microRNAs in Exosomes of Breast Cancer Patients in Search of Molecular Prognostic Factors in Brain Metastases

Brain metastases are the most severe tumorous spread during breast cancer disease. They are associated with a limited quality of life and a very poor overall survival. A subtype of extracellular vesicles, exosomes, are sequestered by all kinds of cells, including tumor cells, and play a role in cell-cell communication. Exosomes contain, among others, microRNAs (miRs). Exosomes can be taken up by other cells in the body, and their active molecules can affect the cellular process in target cells. Tumor-secreted exosomes can affect the integrity of the blood-brain barrier (BBB) and have an impact on brain metastases forming. Serum samples from healthy donors, breast cancer patients with primary tumors, or with brain, bone, or visceral metastases were used to isolate exosomes and exosomal miRs. Exosomes expressed exosomal markers CD63 and CD9, and their amount did not vary significantly between groups, as shown by Western blot and ELISA. The selected 48 miRs were detected using real-time PCR. Area under the receiver-operating characteristic curve (AUC) was used to evaluate the diagnostic accuracy. We identified two miRs with the potential to serve as prognostic markers for brain metastases. Hsa-miR-576-3p was significantly upregulated, and hsa-miR-130a-3p was significantly downregulated in exosomes from breast cancer patients with cerebral metastases with AUC: 0.705 and 0.699, respectively. Furthermore, correlation of miR levels with tumor markers revealed that hsa-miR-340-5p levels were significantly correlated with the percentage of Ki67-positive tumor cells, while hsa-miR-342-3p levels were inversely correlated with tumor staging. Analysis of the expression levels of miRs in serum exosomes from breast cancer patients has the potential to identify new, non-invasive, blood-borne prognostic molecular markers to predict the potential for brain metastasis in breast cancer. Additional functional analyzes and careful validation of the identified markers are required before their potential future diagnostic use.

MiR-9-5p promotes M1 cell polarization in osteoarthritis progression by regulating NF-κB and AMPK signaling pathways by targeting SIRT1

OBJECTIVE

To investigate the roles and regulatory mechanisms of miR-9-5p in the development of osteoarthritis (OA).

METHODS

Synovial tissues from mouse OA model and control groups were collected and miR-9-5p expression levels and macrophage markers were measured with qPCR. The function of miR-9-5p in macrophage polarization was analyzed by flow cytometry and qPCR. Various databases were employed to screen the target genes one of which was validated with dual-luciferase analysis. Following the validation, rescue research was applied, and the signaling pathways were analyzed with Western blotting. Finally, the role of miR-9-5p in the progression of OA was validated in the mouse model.

RESULTS

MiR-9-5p was highly expressed in the synovial tissues of the OA model and was positively associated with M1 markers. Function analysis demonstrated that miR-9-5p could promote the progression of OA by promoting M1 polarization and inhibiting M2 polarization in vivo and in vitro. The mechanism analysis demonstrated that miR-9-5p could regulate macrophage polarization via NF-κB and AMPK signaling pathways by inhibiting SIRT1 expression.

CONCLUSIONS

MiR-9-5p could promote M1 polarization and OA progression by regulating NF-κB and AMPK signaling pathways by inhibiting SIRT1 expression.

Targeting CD82/KAI1 for Precision Therapeutics in Surmounting Metastatic Potential in Breast Cancer

Metastasis is the main cause of mortality in breast cancer patients. There is an unmet need to develop therapies that can impede metastatic spread. Precision oncology has shown great promise for the treatment of cancers, as the therapeutic approach is tailored to a specific group of patients who are likely to benefit from the treatment, rather than the traditional approach of "one size fits all". CD82, also known as KAI1, a glycoprotein belonging to the tetraspanin family and an established metastasis suppressor, could potentially be exploited to hinder metastases in breast cancer. This review explores the prospect of targeting CD82 as an innovative therapeutic approach in precision medicine for breast cancer patients, with the goal of preventing cancer progression and metastasis. Such an approach would entail the selection of a subset of breast cancer patients with low levels of CD82, and instituting an appropriate treatment scheme tailored towards restoring the levels of CD82 in this group of patients. Proposed precision treatment regimens include current modalities of treating breast cancer, in combination with either clinically approved drugs that could restore the levels of CD82, CD82 peptide mimics or non-coding RNA-based therapeutics.

Long noncoding RNA ZFPM2-AS1 promotes the proliferation, migration, and invasion of hepatocellular carcinoma cells by regulating the miR-576-3p/HIF-1α axis

Long noncoding RNA (LncRNA) zinc finger protein multitype 2 antisense RNA 1 (ZFPM2-AS1) is highly expressed in a variety of tumors and is involved in promoting the malignant biological behaviors of cancer cells. However, the mechanism of ZFPM2-AS1 in the progression of hepatocellular carcinoma (HCC) remains to be explored. The ZFPM2-AS1 expression in HCC was measured by quantitative real-time PCR (qRT-PCR); cell counting kit-8, 5-bromo-2'-deoxyuridine (BrdU), and transwell assays were used to confirm the biological functions of ZFPM2-AS1 in regulating the malignant biological behaviors of HCC cells; the luciferase reporter gene assay was employed to detect whether ZFPM2-AS1 could bind to microRNA (miR)-576-3p; the regulatory relationship between ZFPM2-AS1 and miR-576-3p was probed by qRT-PCR; the effects of ZFPM2-AS1 and miR-576-3p on the expression of hypoxia-inducible factor 1α (HIF-1α) were detected by qRT-PCR and Western blot. The expression of ZFPM2-AS1 in HCC tissues, compared with that in normal liver tissues, was significantly upregulated. Knockdown of ZFPM2-AS1 markedly inhibited HCC cell proliferation, migration, and invasion while the overexpression of ZFPM2-AS1 worked oppositely. miR-576-3p could reverse the effects of ZFPM2-AS1 on the biological behaviors of HCC cells. Besides, ZFPM2-AS1 could bind to miR-576-3p and positively regulate the expression of HIF-1α, a target gene of miR-576-3p, by adsorbing miR-576-3p. ZFPM2-AS1 is abnormally highly expressed in HCC and facilitates proliferation, migration, and invasion of HCC cells by adsorbing miR-576-3p and upregulating HIF-1α expression.

Comprehensive Analysis of lncRNA and miRNA Regulatory Network Reveals Potential Prognostic Non-coding RNA Involved in Breast Cancer Progression

Breast cancer is one of the most common malignant tumors in women and is the second leading cause of cancer deaths among women. The tumorigenesis and progression of breast cancer are not well understood. The existing researches have indicated that non-coding RNAs, which mainly include long non-coding RNA (lncRNA) and microRNA (miRNA), have gradually become important regulators of breast cancer. We aimed to screen the differential expression of miRNA and lncRNA in the different breast cancer stages and identify the key non-coding RNA using TCGA data. Based on series test of cluster (STC) analysis, bioinformatics analysis, and negatively correlated relationships, 122 lncRNAs, 67 miRNAs, and 119 mRNAs were selected to construct the regulatory network of lncRNA and miRNA. It was shown that the miR-93/20b/106a/106b family was at the center of the regulatory network. Furthermore, 6 miRNAs, 10 lncRNAs, and 15 mRNAs were significantly associated with the overall survival (OS, log-rank P < 0.05) of patients with breast cancer. Overexpressed miR-93 in MCF-7 breast cancer cells was associated with suppressed expression of multiple lncRNAs, and these downregulated lncRNAs (MESTIT1, LOC100128164, and DNMBP-AS1) were significantly associated with poor overall survival in breast cancer patients. Therefore, the miR-93/20b/106a/106b family at the core of the regulatory network discovered by our analysis above may be extremely important for the regulation of lncRNA expression and the progression of breast cancer. The identified key miRNA and lncRNA will enhance the understanding of molecular mechanisms of breast cancer progression. Targeting these key non-coding RNA may provide new therapeutic strategies for breast cancer treatment and may prevent the progression of breast cancer from an early stage to an advanced stage.

Identification of miRNA Signature in Breast Cancer to Predict Neoadjuvant Chemotherapy Response

Background: Chemotherapy failure causes high breast cancer recurrence and poor patient prognosis. Thus, we studied a cohort of novel biomarkers to predict chemotherapeutic response in breast cancer. In this study, miRNA expression profiling was performed on 10 breast cancer punctured specimens sensitive to chemotherapy (MP grade 4, 5) and 10 chemotherapy resistant (MP grade 1). Differentially expressed miRNAs were verified by qRT-PCR in 60 initial samples, 59 validated samples and 71 independent samples. A miRNA signature was generated using a Logistic regression model. A receiver operating characteristic (ROC) test was used to assess specificity and sensitivity of single miRNA and miRNA signature. Target genes regulated by miRNAs and their involved signaling pathways were analyzed using GO enrichment and KEGG software. MiRNAs expression were separately compared with ER, PR, HER2 immunohistochemical staining and different drugs. qRT-PCR showed that the high expression of miR-23a-3p, miR-200c-3p, miR-214-3p and the low expression of miR-451a and miR-638 were closely related to chemoresistance. According to the formula for calculating the drug resistance risk, patients in the high-risk group were more likely to develop chemotherapy resistance than the low-risk group. Bioinformatics analysis showed that 5 miRNAs and target genes are mainly involved in p53, ubiquitin-mediated proteolysis, mTOR, Wnt, cells skeletal protein regulation, cell adhesion and ErbB signaling pathways. miR-451a expression was associated with ER, HER-2 status and anthracyclines. A miRNA signature of chemotherapeutic response may be clinically valuable for improving current chemotherapy regimens of individual treatment for patients with breast cancer.

Deciphering the role of microRNAs in mustard gas-induced toxicity

Mustard gas (sulfur mustard, SM), a highly vesicating chemical warfare agent, was first deployed in warfare in 1917 and recently during the Iraq-Iran war (1980s) and Syrian conflicts (2000s); however, the threat of exposure from stockpiles and old artillery shells still looms large. Whereas research has been long ongoing on SM-induced toxicity, delineating the precise molecular pathways is still an ongoing area of investigation; thus, it is important to attempt novel approaches to decipher these mechanisms and develop a detailed network of pathways associated with SM-induced toxicity. One such avenue is exploring the role of microRNAs (miRNAs) in SM-induced toxicity. Recent research on the regulatory role of miRNAs provides important results to fill in the gaps in SM toxicity-associated mechanisms. In addition, differentially expressed miRNAs can also be used as diagnostic markers to determine the extent of toxicity in exposed individuals. Thus, in our review, we have summarized the studies conducted so far in cellular and animal models, including human subjects, on the expression profiles and roles of miRNAs in SM- and/or SM analog-induced toxicity. Further detailed research in this area will guide us in devising preventive strategies, diagnostic tools, and therapeutic interventions against SM-induced toxicity.

Candidate circulating microRNAs as potential diagnostic and predictive biomarkers for the monitoring of locally advanced breast cancer patients

This study aimed at investigating the expression of candidate microRNAs (miRs), at initial diagnosis, during neoadjuvant chemotherapy, and after the tumor resection in locally advanced breast cancer patients. Plasma samples were collected from locally advanced breast cancer patients (n = 30) and healthy subjects (n = 20) for the detection of candidate miRs' expression using the real-time quantitative polymerase chain reaction. At initial locally advanced breast cancer diagnosis, the expression of miR-21, miR-181a, and miR-10b was significantly increased, whereas that of miR-145 and let-7a was significantly decreased, compared to the healthy individuals. The diagnostic accuracy of miR-21 was superior to both carcinoembryonic antigen and carcinoma antigen 15-3 as diagnostic biomarkers for locally advanced breast cancer. By the end of the treatment, the expression of altered miRs rebound to control values. The expression levels of candidate plasma miRs are useful diagnostic biomarkers, as well as monitoring a proper response for locally advanced breast cancer patients to the treatment. Furthermore, miR-10b and miR-21 can be considered as predictive biomarkers for progression-free survival.

Connecting the Missing Dots: ncRNAs as Critical Regulators of Therapeutic Susceptibility in Breast Cancer

Whether acquired or de novo, drug resistance remains a significant hurdle in achieving therapeutic success in breast cancer (BC). Thus, there is an urge to find reliable biomarkers that will help in predicting the therapeutic response. Stable and easily accessible molecules such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are regarded as valuable prognostic biomarkers and therapeutic targets since they act as crucial regulators of the various mechanisms involved in BC drug resistance. Here, we reviewed the current literature on ncRNAs as mediators of resistance to systemic therapies in BC. Interestingly, upon integrating data results from individual studies, we concluded that miR-221, miR-222, miR-451, Urothelial Carcinoma Associated 1 (UCA1), and Growth arrest-specific 5 (GAS5) are strong candidates as prognostic biomarkers and therapeutic targets since they are regulating multiple drug resistance phenotypes in BC. However, further research around their clinical implications is needed to validate and integrate them into therapeutic applications. Therefore, we believe that our review may provide relevant evidence for the selection of novel therapeutic targets and prognostic biomarkers for BC and will serve as a foundation for future translational research in the field.

Circular RNA VMA21 ameliorates sepsis-associated acute kidney injury by regulating miR-9-3p/SMG1/inflammation axis and oxidative stress

Accumulating evidence suggests that circular RNAs have the abilities to regulate gene expression during the progression of sepsis‐associated acute kidney injury. Circular RNA VMA21 (circVMA21), a recent identified circular RNA, could reduce apoptosis to alleviate intervertebral disc degeneration in rats and protect WI‐38 cells from lipopolysaccharide‐induced injury. However, the role of circVMA21 in sepsis‐associated acute kidney injury (sepsis‐associated AKI) is unknown. In this study, we first demonstrated that circVMA21 alleviated sepsis‐associated AKI by reducing apoptosis and inflammation in rats and HK‐2 cells. Additionally, to explore the molecule mechanism underlying the amelioration, after the bioinformatics analysis, we confirmed that miR‐9‐3p directly bound to circVMA21 by luciferase and RNA immunoprecipitation assay, and the effector protein of miR‐9‐3p was SMG1. Furthermore, the oxidative stress caused by sepsis‐associated AKI was down‐regulated by circVMA21. In conclusion, circVMA21 plays an important role in the regulating sepsis‐associated AKI via adjusting miR‐9‐39/SMG1/inflammation axis and oxidative stress.

Potential miRNAs for miRNA-Based Therapeutics in Breast Cancer

MicroRNAs (miRNAs) are small non-coding RNAs that can post-transcriptionally regulate the genes involved in critical cellular processes. The aberrant expressions of oncogenic or tumor suppressor miRNAs have been associated with cancer progression and malignancies. This resulted in the dysregulation of signaling pathways involved in cell proliferation, apoptosis and survival, metastasis, cancer recurrence and chemoresistance. In this review, we will first (i) provide an overview of the miRNA biogenesis pathways, and in vitro and in vivo models for research, (ii) summarize the most recent findings on the roles of microRNAs (miRNAs) that could potentially be used for miRNA-based therapy in the treatment of breast cancer and (iii) discuss the various therapeutic applications.

Clinical Potentials of miR-576-3p, miR-613, NDRG2 and YKL40 in Colorectal Cancer Patients

Introduction:

Colorectal cancer (CRC) is the most common type of gastrointestinal tract cancers. This investigation aim was to assess the expression of miR-576-3p and miR-613 in CRC patients in addition to NDRG2 and YKL40 serum levels determination to decide their diagnostic and prognostic significance.

Methods:

Sixty early diagnosed CRC patients prior to any treatment in addition to twelve healthy subjects were enrolled in this study. Blood samples were taken from subjects and allowed for clotting and centrifugation, then the collected sera were stored at -80ºC till it were used for detection of our molecular biomarkers. The mature miRNAs expressions (miR-576-3p and miR-613) were detected in serum by qRT-PCR, while NDRG2 and YKL40 serum levels were determined by ELISA. In addition, the correlation of the measured parameters with the clinicopathological data of the patients was investigated.

Results:

The study results showed that both miRNA-576-3p and miRNA-613 were down-regulated in CRC patients with fold change 0.33, 0.36; respectively. A significant positive correlation was observed between miR-576-3p and miR-613 (r = 0.75, p < 0.001). NDRG2 serum levels were decreased in patients compared to the control group but the decrease wasn’t statistically significant. On the other hand, it was observed that YKL40 serum level was significantly increased in CRC patients compared to control (p-value < 0.001). Furthermore, YKL40 showed a very high diagnostic value (AUC = 0.97, specificity = 91.7%, sensitivity = 96%, p-value = 0.0001).

Conclusion:

The observations of this investigation concluded that, the expressions of miR-576-3p and miR-613 in addition to YKL40 serum levels determinations may help in the diagnosis of CRC.

Association of miR-760 with cancer: An overview

MicroRNAs (miRNAs) are small non-coding RNA molecules of around 22 nucleotides in length. They are crucially involved in the post transcriptional regulation and thus play a significant role in the modulation of different diseases. Several studies have suggested that miRNA expression is dysregulated in various cancers through different mechanisms and the dysregulated miRNA in return affects different cancer hallmarks including cell proliferation, cell death suppression, metastasis and angiogenesis. Compilation of the available miRNA data can be a stimulator for proper understanding of the correlation between the miRNA expression and cancer progression. In this review, we have focussed on the role of miR-760 in the progression of different cancer. MicroRNA-760 (miR-760) has been found to be down regulated in various cancers, thus it can be utilized as a possible prognostic marker for cancer detection. Here, we have tried to fill a gap regarding the role of miR-760 in relation to cervical cancer also. Moreover, unravelling the role of miR-760 in different cancers will enlighten the researchers with proper understanding of biology of miR-760 in regulation of different cancers.

MEG3 Alleviated LPS-Induced Intestinal Injury in Sepsis by Modulating miR-129-5p and Surfactant Protein D

Sepsis and intestinal injury triggered by sepsis are common in intensive care units, which can contribute to a high mortality. lncRNAs can modulate gene expression, and they are closely involved in multiple diseases, including sepsis. In our present study, we investigated the biological function of MEG3 in sepsis, especially during the intestinal injury. Currently, we observed that in LPS-induced sepsis mouse models, the intestinal injury was triggered. Meanwhile, we reported that MEG3 was greatly decreased in vivo, with an increase of miR-129-5p and inhibition of SP-D. Then, MEG3 was overexpressed, and we found that its overexpression repressed the intestinal injury via downregulating miR-129-5p in sepsis mice. Moreover, TNF-α and IL-6 expression was elevated in intestinal tissues compared to the control groups. MEG3 restrained the activation of TNF-α and IL-6, in sepsis models. Subsequently, to induce the inflammatory injury of sepsis, human colorectal Caco2 cells were treated with 10 ng/ml LPS. 10 ng/ml LPS significantly inhibited Caco2 cell proliferation and increased the apoptosis. Additionally, MEG3 was decreased whereas miR-129-5p was obviously increased in Caco2 cells incubated with LPS. Interestingly, we showed that MEG3 repressed cell apoptosis partly and enhanced Caco2 cell proliferation. miR-129-5p overexpression could reverse the effect of MEG3 in vitro. Previously, we proved SP-D was reduced in sepsis and it depressed the intestinal injury in vivo. Finally, the correlation among MEG3, miR-129-5p, and SP-D was predicted and confirmed in our investigation. These findings indicated that MEG3 might be a potential target for intestinal damage caused by sepsis via regulating miR-129-5p and SP-D.

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.

Clinical Theragnostic Relationship between Drug-Resistance Specific miRNA Expressions, Chemotherapeutic Resistance, and Sensitivity in Breast Cancer: A Systematic Review and Meta-Analysis

Awareness of breast cancer has been increasing due to early detection, but the advanced disease has limited treatment options. There has been growing evidence on the role of miRNAs involved in regulating the resistance in several cancers. We performed a comprehensive systematic review and meta-analysis on the role of miRNAs in influencing the chemoresistance and sensitivity of breast cancer. A bibliographic search was performed in PubMed and Science Direct based on the search strategy, and studies published until December 2018 were retrieved. The eligible studies were included based on the selection criteria, and a detailed systematic review and meta-analysis were performed based on PRISMA guidelines. A random-effects model was utilised to evaluate the combined effect size of the obtained hazard ratio and 95% confidence intervals from the eligible studies. Publication bias was assessed with Cochran’s Q test, I² statistic, Orwin and Classic fail-safe N test, Begg and Mazumdar rank correlation test, Duval and Tweedie trim and fill calculation and the Egger’s bias indicator. A total of 4584 potential studies were screened. Of these, 85 articles were eligible for our systematic review and meta-analysis. In the 85 studies, 188 different miRNAs were studied, of which 96 were upregulated, 87 were downregulated and 5 were not involved in regulation. Overall, 24 drugs were used for treatment, with doxorubicin being prominently reported in 15 studies followed by Paclitaxel in 11 studies, and 5 drugs were used in combinations. We found only two significant HR values from the studies (miR-125b and miR-4443) and our meta-analysis results yielded a combined HR value of 0.748 with a 95% confidence interval of 0.508–1.100; p-value of 0.140. In conclusion, our results suggest there are different miRNAs involved in the regulation of chemoresistance through diverse drug genetic targets. These biomarkers play a crucial role in guiding the effective diagnostic and prognostic efficiency of breast cancer. The screening of miRNAs as a theragnostic biomarker must be brought into regular practice for all diseases. We anticipate that our study serves as a reference in framing future studies and clinical trials for utilising miRNAs and their respective drug targets.

MicroRNA-370 functions as a tumor suppressor in hepatocellular carcinoma via inhibition of the MAPK/JNK signaling pathway by targeting BEX2

Hepatocellular carcinoma (HCC) is a primary malignancy of the liver and occurs predominantly in patients with underlying chronic liver disease and cirrhosis. Accumulating studies have revealed that microRNAs (miRNAs) play a critical role in the development and progression of HCC. Through microarray-based gene expression profiling of HCC, miR-370, and BEX2 were identified in HCC. Hence, this study aimed to evaluate their abilities on the cellular processes in HCC. It was determined that BEX2 was highly expressed and miR-370 was poorly expressed in HCC cell lines and tissues. Then, the cell line presenting with the highest BEX2 expression and the lowest miR-370 expression was selected for subsequent gain- and loss-of-function experimentation. The antitumor effect of miR-370 on HCC cell proliferation, invasion, migration, and apoptosis, as well as the MAPK/JNK signaling pathway was examined. Meanwhile, the interaction among miR-370, BEX2, and MAPK/JNK signaling pathway was identified. BEX2 is verified to be a target of miR-370. Moreover, miR-370 exerted antitumor effect on HCC development through suppression of the MAPK/JNK signaling pathway by targeting BEX2. Later, it was further verified by in vivo experiment that overexpression of miR-370 inhibited tumor growth. Above results provide evidence that miR-370 could downregulate BEX2 gene and inhibit activation of MAPK/JNK signaling pathway, thus inhibiting the development of HCC. It provides a worth-trying novel therapeutic target for HCC treatment.

MicroRNAs as Potential Biomarkers for Chemoresistance in Adenocarcinomas of the Esophagogastric Junction

Concerning adenocarcinomas of the esophagogastric junction, neoadjuvant chemotherapy is regularly implemented, but patients' response varies greatly, with some cases showing no therapeutic effect, being deemed as chemoresistant. Small, noncoding RNAs (miRNAs) have evolved as key players in biological processes, including malignant diseases, often promoting tumor growth and expansion. In addition, specific miRNAs have been implicated in the development of chemoresistance through evasion of apoptosis, cell cycle alterations, and drug target modification. We performed a retrospective study of 33 patients receiving neoadjuvant chemotherapy by measuring their miRNA expression profiles. Histologic tumor regression was evaluated using resection specimens, while miRNA profiles were prepared using preoperative biopsies without prior therapy. A preselected panel of 96 miRNAs, known to be of importance in various malignancies, was used to test for significant differences between responsive (chemosensitive) and nonresponsive (chemoresistant) cases. The cohort consisted of 12 nonresponsive and 21 responsive cases with the following 4 miRNAs differentially expressed between both the groups: hsa-let-7f-5p, hsa-miRNA-221-3p, hsa-miRNA-31-5p, and hsa-miRNA-191-5p. The former 3 showed upregulation in chemoresistant cases, while the latter showed upregulation in chemosensitive cases. In addition, significant correlation between high expression of hsa-miRNA-194-5p and prolonged survival could be demonstrated (p value <0.0001). In conclusion, we identified a panel of 3 miRNAs predicting chemoresistance and a single miRNA contributing to chemosensitivity. These miRNAs might function as prognostic biomarkers and enable clinicians to better predict the effect of one or more reliably select patients benefitting from (neoadjuvant) chemotherapy.

MicroRNA‑576‑3p inhibits the migration and proangiogenic abilities of hypoxia‑treated glioma cells through hypoxia‑inducible factor‑1α

The most common and aggressive type of brain cancer in adults is glioblastoma multiforme (GBM), and hypoxia is a common feature of glioblastoma. As the histological features of glioma include capillary endothelial cell proliferation, they are highly prone to invading the surrounding normal brain tissue, which is often one of the reasons for the failure of treatment. However, the mechanisms involved in this process are not fully understood. MicroRNAs (miRs) are a class of non‑coding RNA that are able to inhibit the malignant progression of tumor cells through the regulation of downstream genes. In the present study, the low expression of miR‑576‑3p was detected in glioma samples and hypoxia‑treated glioma cells using a reverse transcription‑quantitative polymerase chain reaction. The present study focused on the effects of miR‑576‑3p on hypoxia‑induced glioma. The results of the functional experiments revealed that the overexpression of miR‑576‑3p significantly inhibited the migration and pro‑angiogenic abilities of the glioma cells under hypoxic conditions (P<0.05) compared with in the lentivirus‑miR‑negative control group. Furthermore, luciferase reporter gene assays were used to validate the hypothesis that miR‑576‑3p interacts with the 3'‑untranslated region of hypoxia‑inducible factor‑1α (HIF‑1α) and induces a reduction in the protein levels of matrix metalloproteinase‑2 and vascular endothelial growth factor. Rescue experiments demonstrated that the restoration of HIF‑1α expression attenuated the effect of miR‑576‑3p on the migration and proangiogenic abilities of glioma cells. In conclusion, the present study confirms that miR‑576‑3p is a novel GBM inhibitor and its inhibition of the migration and proangiogenic capacity of hypoxia‑induced glioma cells is mediated by HIF‑1α.

Overexpression of microRNA-620 facilitates the resistance of triple negative breast cancer cells to gemcitabine treatment by targeting DCTD

Patients with triple negative breast cancer (TNBC) have a poor survival rate following chemotherapy due to drug resistance. Notably, the molecular mechanism of drug resistance remains elusive. Between December 2011 and December 2014, 36 TNBC samples were obtained from Liaocheng People's Hospital. Three gemcitabine-resistant MDA-MB-231 cell lines (MDA-MB-231rGEM1, MDA-MB-231rGEM2 and MDA-MB-231rGEM3) were obtained by exposure of MDA-MB-231 cells to increasing concentrations of gemcitabine for >12 months. Reverse transcription-quantitative polymerase chain reaction was performed to detect the expression levels of specific genes, including microRNA (miR)-620, ATP-binding cassette sub-family B member 1 (ABCB1), ABCC10, cytidine monophosphate kinase, deoxycytidine monophosphate deaminase (DCTD), nucleoside diphosphate kinase 1 (NME1), ribonucleoside-diphosphate reductase large subunit (RRM1) and RRMB2. Western blot analysis was performed to assess the protein expression levels of DCTD. Furthermore, cell proliferation was assessed using a Cell Counting Kit-8 assay and cell apoptosis was detected using an Annexin V/Dead Cell Apoptosis kit. Interactions between miR-620 and DCTD were predicted using TargetScan and detected with the dual luciferase reporter assay. Elevation of miR-620 expression levels were detected in two of the assessed gemcitabine-resistant MDA-MB-231 cell lines compared with MDA-MB-231 cells. Gemcitabine induced significant elevation of miR-620 in MDA-MB-231 cells. An increase of DCTD at mRNA and protein expression levels in MDA-MB-231rGEM1 cells was observed compared with those in MDA-MB-231 cells. Results suggested that DCTD was directly regulated by miR-620. Inhibition of miR-620 and overexpression of DCTD reversed gemcitabine resistance in MDA-MB-231rGEM1 cells via inducing cell apoptosis and cell growth arrest. A negative correlation was identified between miR-620 and DCTD mRNA expression levels in patients with TNBC. The present results demonstrated that overexpression of miR-620 could contribute to the development of gemcitabine resistance in patients with TNBC via the direct downregulation of DCTD.

Inhibition of LINC00994 represses malignant behaviors of pancreatic cancer cells: interacting with miR-765-3p/RUNX2 axis

Pancreatic cancer exhibits one of the worst prognosis of all human cancers, and it is associated with gene dysregulation. Our microarray results first indicated long intergenic non-protein coding RNA 994 (LINC00994) as an upregulated long non-coding RNA (lncRNA) and miR-765-3p as a downregulated microRNA (miRNA) in pancreatic cancer tissues (Fold change ≥ 2 and P < 0.05; three paired samples). To investigate the role of LINC00994 in pancreatic carcinogenesis, a pair of short hairpin RNA (shRNA) was used to stably knock down the endogenous expression of LINC00994 in Panc-1 and AsPC-1 pancreatic cancer cells in vitro. We found that LINC00994 silencing inhibited the growth, migration and invasion, and promoted the G1 cell cycle arrest and apoptosis in Panc-1 and AsPC-1 cells. Furthermore, the expression of LINC00994 was negatively correlated with that of miR-765-3p in 10 pancreatic cancer specimens. Runt-related transcription factor 2 (RUNX2), a molecule that contributes to the aggressive behaviors of pancreatic cancer, was herein verified as a novel target for miR-765-3p. Like LINC00994, its expression was elevated in pancreatic cancers. Silencing of LINC00994 and RUNX2 reduced each other's expression in both Panc-1 and AsPC-1 cells. RUNX2 3'UTR and LINC00994 competed to bind miR-765-3p. Additionally, LINC00994-silenced cells regained their aggressive behaviors when miR-765-3p was antagonized, which was accompanied with RUNX2 re-expression. Collectively, our study reveals that LINC00994 contributes to the malignant behaviors of pancreatic cancer cells by preventing miR-765-3p from targeting RUNX2. LINC00994 can be considered as a novel therapeutic target against pancreatic cancer.

Prognostic role of miR-760 in hepatocellular carcinoma

Previous studies have demonstrated that microRNA (miR)-760 serves an important role in various cancer types. However, to the best of our knowledge, its role in hepatocellular carcinoma (HCC) has not been fully elucidated. The current study investigated the prognostic role of miR-760 in HCC by using the Kaplan-Meier plotter database. The current data indicated that low expression of miR-760 was associated with higher overall survival (OS) for all patients with HCC from both the RNA-seq [hazard ratio (HR)=2.04; 95% confidence interval (CI)=1.44–2.89; P=4.9×10⁻⁵] and the non-commercial spotted microarray (HR=1.71; CI=1.05–2.76; P=0.028). In the RNA-seq platform, a lower expression of miR-760 was strongly associated with improved OS in male patients with HCC, but not in female patients with HCC. Additionally, low expression of miR-760 was associated with improved OS in patients with stage I, II and III HCC, and was associated with improved OS in Asian and Caucasian patients. The current results indicated that miR-760 serves as an oncogene for HCC and high expression of miR-760 is significantly associated with tumor progression and poor prognosis in patients with HCC.

Emerging roles of circRNA_NEK6 targeting miR-370-3p in the proliferation and invasion of thyroid cancer via Wnt signaling pathway

OBJECTIVE

To identify the significantly altered circRNAs and mRNAs in thyroid cancer, investigate their target miRNAs and determine their biological functions.

METHODS

The differentially expressed circRNAs, mRNAs and pathways in thyroid cancer were identified by microarray analysis and gene set enrichment analysis (GSEA). The correlative circRNAs and mRNAs were found out through Pearson correlative analysis. The common target miRNAs of circNEK6 and FZD8 related to thyroid cancer was screened out through Targetscan, miRanda and HMDD analysis. The mRNA and protein expressions in thyroid cancer tissues and cells were detected by qRT-PCR and western blot. CircRNA was confirmed by the RNase R digestion and nucleic acid electrophoresis. The target relationships were verified by the dual luciferase reporter assay. Cell viability, invasion and apoptosis were determined by MTT assay, Transwell assay and flow cytometry, respectively.

RESULTS

CircNEK6 and FZD8 were significantly up-regulated in thyroid cancer, with strong correlations. The Wnt signaling pathway was activated in thyroid cancer. MiR-370-3p was the common target miRNA of circNEK6 and FZD8, and it was down-regulated in thyroid cancer. Overexpression of circNEK6 and FZD8 could promote the growth and invasion of thyroid cancer cells, while up-regulation of miR-370-3p could suppress thyroid cancer progression and inhibit the Wnt signaling pathway. MiR-370-3p's effect on thyroid cancer cells could be rescued by circNEK6 or FZD8.

CONCLUSION

CircNEK6 promoted the progression of thyroid cancer through up-regulating FZD8 and activating Wnt signaling pathway by targeting miR-370-3p.

MicroRNA-760 Inhibits Doxorubicin Resistance in Hepatocellular Carcinoma through Regulating Notch1/Hes1-PTEN/Akt Signaling Pathway

Accumulating studies have suggested that microRNA-760 (miR-760) plays an important role in chemoresistance of various cancer cells. However, whether miR-760 regulates the chemoresistance of hepatocellular carcinoma (HCC) remains unclear. In this study, we found that miR-760 was decreased in HCC cell lines, and doxorubicin (Dox) treatment significantly decreased miR-760 expression in HCC cells. Overexpression of miR-760 sensitized HCC cells to Dox-induced cytotoxicity and apoptosis, whereas miR-760 inhibition showed the opposite effects. Notch1 was predicted as a target gene of miR-760. miR-760 negatively regulated Notch1 expression and Notch1/Hes1 signaling. Overexpression of miR-760 increased PTEN expression and decreased the phosphorylation of Akt. Activation of Notch signaling significantly reversed the inhibitory effect of miR-760 on Dox-resistance and abrogated the effect of miR-760 on the PTEN/Akt signaling pathway in HCC cells. Overall, our results demonstrate that miR-760 inhibits Dox-resistance in HCC cells through inhibiting Notch1 and promoting PTEN expression.

Chemoresistance‑related long non‑coding RNA expression profiles in human breast cancer cells

Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death in females worldwide. Chemoresistance has been a major reason for the drug therapy failure. The present study performed a microarray analysis between MCF-7 and MCF-7/adriamycin (ADR) cells, and intended to identify long non-coding (lnc)RNA expression character in drug resistant breast cancer cells. MCF-7/ADR cells were induced from MCF-7 cells via pulse-selection with doxorubicin for 4 weeks, and the resistance to doxorubicin of ADR cells was confirmed by MTT assay. Microarray analysis was performed between MCF-7 and MCF-7/ADR cells. Total RNA was extracted from the two cell lines respectively and was transcribed into cDNA. The results of the microarray were verified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Gene Ontology (GO) and pathways analysis were conducted to enrich the dysregulated lncRNAs presented in the microarray results. Compared to the MCF-7 cells, 8,892 lncRNAs were differentially expressed in MCF/ADR cells (absolute fold-change >2.0). A total of 32 lncRNAs were selected for RT-qPCR by fold-change filtering, standard Student's t-test, and multiple hypothesis testing. Among the dysregulated lncRNAs, AX747207 was prominent because its associated gene RUNX3 was previously reported to be relative to malignant tumor chemoresistance. GO analysis results also indicated some biological processes and molecular functions linked to chemoresistance. The pathway enrichment results provided some potential pathways associated with chemoresistance. In the present study, the authors intended to identify lncRNA expression character in drug resistant cell line MCF-7/ADR, corresponding to the parental MCF-7 cell line. In addition, the study identified the lncRNA AX747207, and its potential targeted gene RUNX3, may be related to chemoresistance in breast cancer. These results may new insights into exploring the mechanisms of chemoresistance in breast cancer.

MiR-760 suppresses human colorectal cancer growth by targeting BATF3/AP-1/cyclinD1 signaling

Background

Recent studies have reported that microRNAs (miRNAs) often function as negative post-transcriptional regulators with altered expression levels found in colorectal cancer (CRC). There have been few studies on miRNAs that regulate the oncogenic alterations in CRC. Here, we aim to explore the anti-cancer miRNA and the potential mechanisms by which miRNAs modulate CRC progression.

Methods

We performed an integrated analysis of CRC miRNA expression datasets in The Cancer Genome Atlas (TCGA). The miRNA with the lowest expression, miR-760, was validated in an independent validation sample cohort of 76 CRC tissues. Functional assays, such as CCK-8 assay, colony formation assay, and CFSE staining, were used to determine the oncogenic role of miR-760 in human CRC progression. Furthermore, western blotting and dual-luciferase reporter assay were used to determine the mechanism by which miR-760 promotes proliferation of CRC cells. Xenograft nude mouse models were used to determine the role of miR-760 in CRC tumorigenicity in vivo. Immunohistochemical assays were conducted to study the relationship between miR-760 expression and basic leucine zipper transcriptional factor ATF-like 3 (BATF3) expression in human CRC samples.

Results

miR-760 was markedly downregulated in CRC tissues, and low miR-760 expression was associated with poor prognosis among CRC patients. Upregulation of miR-760 suppressed CRC cell proliferation, whereas downregulation of miR-760 promoted CRC proliferation in vitro. Additionally, we identified BATF3 as a direct target of miR-760, and that the essential biological function of miR-760 during CRC progression both in vitro and in vivo is to suppress the expression of BATF3 and downstream cyclinD1 via AP-1 transcription factor. Finally, we showed a significant correlation between miR-760 and BATF3 expression in CRC tissues.

Conclusions

miR-760 inhibited CRC growth by downregulating BATF3/AP-1/ cyclinD1 signaling.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0757-8) contains supplementary material, which is available to authorized users.

Gene and MicroRNA Perturbations of Cellular Response to Pemetrexed Implicate Biological Networks and Enable Imputation of Response in Lung Adenocarcinoma

Pemetrexed is indicated for non-small cell lung carcinoma and mesothelioma, but often has limited efficacy due to drug resistance. To probe the molecular mechanisms underlying chemotherapeutic response, we performed mRNA and microRNA (miRNA) expression profiling of pemetrexed treated and untreated lymphoblastoid cell lines (LCLs) and applied a hierarchical Bayesian method. We identified genetic variation associated with gene expression in human lung tissue for the most significant differentially expressed genes (Benjamini-Hochberg [BH] adjusted p < 0.05) using the Genotype-Tissue Expression data and found evidence for their clinical relevance using integrated molecular profiling and lung adenocarcinoma survival data from The Cancer Genome Atlas project. We identified 39 miRNAs with significant differential expression (BH adjusted p < 0.05) in LCLs. We developed a gene expression based imputation model of drug sensitivity, quantified its prediction performance, and found a significant correlation of the imputed phenotype generated from expression data with survival time in lung adenocarcinoma patients. Differentially expressed genes (MTHFD2 and SUFU) that are putative targets of differentially expressed miRNAs also showed differential perturbation in A549 fusion lung tumor cells with further replication in A549 cells. Our study suggests pemetrexed may be used in combination with agents that target miRNAs to increase its cytotoxicity.

MiR-370 promotes apoptosis in colon cancer by directly targeting MDM4

MicroRNA (miR)-370 functions as a tumor suppressor or promoter in several cancers. However, the expression and biological role of miR-370 in colon cancer remains undefined. In the present study, miR-370 expression in both normal and malignant colon tissues was quantified by quantitative polymerase chain reaction. An in vitro cell viability and apoptosis assay and an in vitro xenograft tumor model were employed to investigate the role of miR-370 on colon cancer growth. Furthermore, the potential direct target of miR-370 was identified using a luciferase assay. Our results demonstrate that down-regulation of miR-370 expression occurs in malignant tissues and miR-370 expression is inversely correlated with tumor grade. Moreover, we determined that miR-370 functions as a tumor suppressor in colon cancer by inhibiting cell proliferation and promoting cell apoptosis. In addition, overexpression of miR-370 impairs xenograft tumor growth in nude mice. Mechanistically, mouse double minute 4 (MDM4) was demonstrated to be a potential direct target of miR-370, inducing apoptosis in colon cancer. Collectively, these findings suggest that upregulation of miR-370 may impair colon tumor growth by directly targeting MDM4. These findings provide a new direction for the diagnosis and treatment of colon cancer.

Prediction of miRNA-disease Associations using an Evolutionary Tuned Latent Semantic Analysis

MicroRNAs, small non-coding elements implied in gene regulation, are very interesting biomarkers for various diseases such as cancers. They represent potential prodigious biotechnologies for early diagnosis and gene therapies. However, experimental verification of microRNA-disease associations are time-consuming and costly, so that computational modeling is a proper solution. Previously, we designed MiRAI, a predictive method based on distributional semantics, to identify new associations between microRNA molecules and human diseases. Our preliminary results showed very good prediction scores compared to other available methods. However, MiRAI performances depend on numerous parameters that cannot be tuned manually. In this study, a parallel evolutionary algorithm is proposed for finding an optimal configuration of our predictive method. The automatically parametrized version of MiRAI achieved excellent performance. It highlighted new miRNA-disease associations, especially the potential implication of mir-188 and mir-795 in various diseases. In addition, our method allowed to detect several putative false associations contained in the reference database.

Alteration of miRNA expression in a sulfur mustard resistant cell line

BACKGROUND

MicroRNAs (miRNAs) are responsible for post-transcriptional control of protein expression. Numerous miRNAs have been identified to be responsible for the resistance of tumor cells to cytostatic drugs. Possibly, the same miRNAs also play a role in the sulfur mustard (SM)-resistance of the keratinocyte cell line HaCaT/SM as alkylating cytostatics exhibit similar cytotoxic effects as SM.

METHODS

Basal expression levels of 1920 miRNAs in total were analyzed in HaCaT/SM compared to the origin human keratinocyte cell line HaCaT. The effect for selected miRNAs on cell survival was analyzed using antagomirs for ectopic miRNA level decrease or miRNA mimics for increase. Cell survival was calculated as SM dose-dependent-curves.

RESULTS

Out of 1920 miRNAs analyzed, 49 were significantly up- and 29 were significantly downregulated in HaCaT/SM when compared to HaCaT controls. Out of these, 36 could be grouped in miRNA families. Most of the 15 miRNA family members showed either a common increase or decrease. Only the members of miR-10, miR-154, miR-430 and miR-548 family showed an inconsistent picture. The ectopic increase of miR-181 in HaCaT/SM had a positive effect on cell survival in the presence of SM.

CONCLUSION

In summary, the extensive differences in miRNA expression pattern between these cell lines indicate that specific miRNAs may play a role in the resistance mechanism against sulfur mustard. The miR-125b-2 and miR-181b alone are not responsible for the resistance development against SM, but an ectopic increase of miR-181 even enhances the SM resistance of HaCaT/SM. Improving the resistance in normal keratinocytes by treatment with either both miRNAs together or a different combination might be used as an initial step in development of an innovative new drug or prophylactic agent against SM.

MiR-1268b confers chemosensitivity in breast cancer by targeting ERBB2-mediated PI3K-AKT pathway

Chemoresistance represents a major obstacle to effective therapy for breast cancer. Emerging evidences associated aberrantly expressed miRNAs with tumor development and chemoresistance. MiR-1268b has never been studied in any cancers before, and its roles in mediating tumor progression and drug resistance are still unclear. Selected from miRNA microarray and confirmed by real-time quantitative PCR (RT-qPCR), miR-1268b was found to be significantly upregulated in drug sensitive and ERBB2 negative tissues, as well as in breast cancer patients with low clinical stage. And miR-1268b had a higher expression in chemosensitive breast cancer cell lines, compared with the chemoresistant cell line. Moreover, the results revealed that miR-1268b induced breast cancer cell apoptosis and increased cell chemosensitivity. ERBB2 was demonstrated to be the target gene of miR-1268b by dual-luciferase reporter assays, western blot, and immunocytochemistry. Furthermore, PI3KCA, AKT, BCL2 in the ERBB2-PI3K-AKT signaling pathway were found to be downstream effectors of miR-1268b. In conclusion, miR-1268b increased chemosensitivity, at least in part, via modulation of PI3K-AKT pathway by targeting ERBB2. MiR-1268b may serve as a potential therapeutic target for patients with breast cancers.

Potential genetic damage to nematode offspring following exposure to triclosan during pregnancy

Triclosan (TCS) is widely used as broad-spectrum antibacterial agent. However, it may threaten the health of human offspring if the mother is exposed to TCS during pregnancy. The present study aimed to identify potential mechanisms behind the toxic effect of TCS on the offspring of Caenorhabditis elegans (C. elegans), using this nematode as a suitable animal model. The results of the current study demonstrated that the locomotory behavior and reproductive capacity of C. elegans offspring was severely affected by prenatal exposure to different concentrations of TCS. A high-throughput gene microarray was performed to investigate molecular alterations in C. elegans offspring following TCS exposure during pregnancy. Microarray results indicated that 113 genes were differentially expressed following TCS treatment compared with the control group. Gene ontology analysis demonstrated that these dysregulated genes were primarily associated with neuron development, muscular strength and reproduction. Pathway analysis results demonstrated that differentially expressed genes participated in several signaling pathways, including arginine, proline, and purine metabolism, progesterone-mediated oocyte maturation and neuroactive ligand-receptor interaction. Finally, 7 TCS toxicity-associated genes were confirmed by reverse transcription-quantitative polymerase chain reaction. The present study indicates that TCS exposure during pregnancy may disturb the locomotory behavior and reproductive capacity of C. elegans offspring, primarily through 7 TCS toxicity-associated genes, which merits further study from an environmental health perspective.

Micro-RNAs as Potential Predictors of Response to Breast Cancer Systemic Therapy: Future Clinical Implications

Despite advances in diagnosis and new treatments such as targeted therapies, breast cancer (BC) is still the most prevalent tumor in women worldwide and the leading cause of death. The principal obstacle for successful BC treatment is the acquired or de novo resistance of the tumors to the systemic therapy (chemotherapy, endocrine, and targeted therapies) that patients receive. In the era of personalized treatment, several studies have focused on the search for biomarkers capable of predicting the response to this therapy; microRNAs (miRNAs) stand out among these markers due to their broad spectrum or potential clinical applications. miRNAs are conserved small non-coding RNAs that act as negative regulators of gene expression playing an important role in several cellular processes, such as cell proliferation, autophagy, genomic stability, and apoptosis. We reviewed recent data that describe the role of miRNAs as potential predictors of response to systemic treatments in BC. Furthermore, upon analyzing the collected published information, we noticed that the overexpression of miR-155, miR-222, miR-125b, and miR-21 predicts the resistance to the most common systemic treatments; nonetheless, the function of these particular miRNAs must be carefully studied and further analyses are still necessary to increase knowledge about their role and future potential clinical uses in BC.

A nine-miRNA signature as a potential diagnostic marker for breast carcinoma: An integrated study of 1,110 cases

Growing evidence indicates that microRNAs (miRNAs) play critical roles in the initiation and progression of breast carcinoma (BC) and are promising diagnostic biomarkers. In the present study, we aimed to identify a multi-marker miRNA pool with high diagnostic performance for BC. We collected miRNA expression profiles of BC samples and normal breast tissues from The Cancer Genome Atlas (TCGA) and screened differentially expressed miRNAs by conducting two‑sample t-tests and by calculating log2 fold-change (log2FC) ratios. Statistical significance was established at p<0.001 and |log2FC| >1. Then, we generated receiver operating characteristic (ROC) curves, calculated the area under the curve (AUC) with a 95% confidence interval (95% CI), and calculated the diagnostic sensitivity and specificity using MedCalc software. Additionally, we predicted the targets of candidate miRNAs using 10 online databases: TarBase, miRTarBase, TargetScan, TargetMiner, microRNA.org, RNA22, PicTar-vert, miRDB, PITA and PolymiRTS. Target genes that were predicted by at least four algorithms were chosen, and cooperative targets of multiple miRNAs were further selected for GO and KEGG pathway analyses through the DAVID online tool. Eventually, a total of 66 differentially expressed miRNAs were identified after miRNA expression profiles were analyzed in BC and normal breast samples. Of these, we selected nine dysregulated miRNAs as candidate diagnostic markers: seven upregulated miRNAs (hsa-miR-21, hsa-miR-96, hsa-miR-183, hsa-miR‑182, hsa-miR-141, hsa-miR-200a and hsa-miR-429) and two downregulated miRNAs (hsa-miR-139 and hsa-miR‑145). The ROC curve for the combination of these nine differently expressed miRNAs showed extremely high diagnostic accuracy, with an AUC of 0.995 (95% CI, 0.988‑0.999) and diagnostic sensitivity and specificity of 98.7 and 98.9%, respectively. In conclusion, the combination of these nine miRNAs significantly improved the accuracy of breast cancer diagnosis.

The LIN28/let-7 Pathway in Cancer

Among all tumor suppressor microRNAs, reduced let-7 expression occurs most frequently in cancer and typically correlates with poor prognosis. Activation of either LIN28A or LIN28B, two highly related RNA binding proteins (RBPs) and proto-oncogenes, is responsible for the global post-transcriptional downregulation of the let-7 microRNA family observed in many cancers. Specifically, LIN28A binds the terminal loop of precursor let-7 and recruits the Terminal Uridylyl Transferase (TUTase) ZCCHC11 that polyuridylates pre-let-7, thereby blocking microRNA biogenesis and tumor suppressor function. For LIN28B, the precise mechanism responsible for let-7 inhibition remains controversial. Functionally, the decrease in let-7 microRNAs leads to overexpression of their oncogenic targets such as MYC, RAS, HMGA2, BLIMP1, among others. Furthermore, mouse models demonstrate that ectopic LIN28 expression is sufficient to drive and/or accelerate tumorigenesis via a let-7 dependent mechanism. In this review, the LIN28/let-7 pathway is discussed, emphasizing its role in tumorigenesis, cancer stem cell biology, metabolomics, metastasis, and resistance to ionizing radiation and several chemotherapies. Also, emerging evidence will be presented suggesting that molecular targeting of this pathway may provide therapeutic benefit in cancer.

Usefulness of miRNA profiles for predicting pathological responses to neoadjuvant chemotherapy in patients with human epidermal growth factor receptor 2-positive breast cancer

Pathological complete response (pCR) is considered to be a useful prognostic marker for neoadjuvant chemotherapy to improve the survival rate of patients with operable breast cancer. In the present study, we identified differentially expressed microRNAs (miRNAs) between pCR and non-pCR groups of patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer who received neoadjuvant chemotherapy with trastuzumab. Expression profiles were examined by miRNA microarrays using total RNA extracted from formalin-fixed, paraffin-embedded tissues from pretreatment biopsy specimens. Significant differences were observed in miRNAs associated with pCR between the luminal B-like (HER2-positive) and HER2-positive (nonluminal) subtypes, which were further classified according to their estrogen receptor (ER) status. Prediction models constructed with differentially expressed miRNAs performed well. In conclusion, the combination of miRNA profiles and ER status may improve the accuracy of pCR prediction in patients with HER2-positive breast cancer and enable the development of personalized treatment regimens.

Validation of suitable normalizers for miR expression patterns analysis covering tumour heterogeneity

Oncogenic microRNAs (miRs) have emerged as diagnostic biomarkers and novel molecular targets for anti-cancer drug therapies. Real-time quantitative PCR (qPCR) is one of the most powerful techniques for analyzing miRs; however, the use of unsuitable normalizers might bias the results. Tumour heterogeneity makes even more difficult the selection of an adequate endogenous normalizer control. Here, we have evaluated five potential referenced small RNAs (U6, rRNA5s, SNORD44, SNORD24 and hsa-miR-24c-3p) using RedFinder algorisms to perform a stability expression analysis in i) normal colon cells, ii) colon and breast cancer cell lines and iii) cancer stem-like cell subpopulations. We identified SNORD44 as a suitable housekeeping gene for qPCR analysis comparing normal and cancer cells. However, this small nucleolar RNA was not a useful normalizer for cancer stem-like cell subpopulations versus subpopulations without stemness properties. In addition, we show for the first time that hsa-miR-24c-3p is the most stable normalizer for comparing these two subpopulations. Also, we have identified by bioinformatic and qPCR analysis, different miR expression patterns in colon cancer versus non tumour cells using the previously selected suitable normalizers. Our results emphasize the importance of select suitable normalizers to ensure the robustness and reliability of qPCR data for analyzing miR expression.

MicroRNA-224 promotes the sensitivity of osteosarcoma cells to cisplatin by targeting Rac1

Osteosarcoma is the most common primary bone tumour in children and adolescents. Accumulating evidence has shown that microRNAs (miRNAs) participate in the development of almost all types of cancer. Here, we investigated the role of miR‐224 in the development and progression of osteosarcoma. We demonstrated that miR‐224 was down‐regulated in osteosarcoma cell lines and tissues. Lower miR‐224 levels were correlated with shorter survivalin osteosarcoma patients. Furthermore, overexpression of miR‐224 suppressed osteosarcoma cell proliferation, migration and invasion and contributed to the increased sensitivity of MG‐63 cells to cisplatin. We identified Rac1 as a direct target gene of miR‐224 in osteosarcoma. Rac1 expression was up‐regulated in the osteosarcoma cell lines and tissues, and there was an inverse correlation between Rac1 and miR‐224 expression in osteosarcoma tissues. Furthermore, rescuing Rac1 expression decreased the sensitivity of miR‐224‐overexpressing MG‐63 cells to cisplatin. We also demonstrated that ectopic expression of Rac1 promoted the proliferation, migration and invasion of miR‐224‐overexpressing MG‐63 cells. These data suggest that miR‐224 plays a tumour suppressor role in the development of osteosarcoma and is related to the sensitivity of osteosarcoma to cisplatin.