MiR-124 targets Slug to regulate epithelial-mesenchymal transition and metastasis of breast cancer

A Review of miRNA Regulation in Japanese Encephalitis (JEV) Virus Infection

Japanese encephalitis (JE) is a mosquito-borne disease that causes neuronal damage and inflammation of microglia, and in severe cases, it can be fatal. JE infection can resist cellular immune responses and survive in host cells. Japanese encephalitis virus (JEV) infects macrophages and peripheral blood lymphocytes. In addition to regulating biological signaling pathways, microRNAs in cells also influence virus-host interactions. Under certain circumstances, viruses can change microRNA production. These changes affect the replication and spread of the virus. Host miRNAs can contain viral pathogenicity by downregulating the antiviral immune response pathways. Simultaneous profiling of miRNA and messenger RNA (mRNA) could help us detect pathogenic factors, and dual RNA detection is possible. This work highlights important miRNAs involved in human JE infection. In this study, we have shown the important miRNAs that play significant roles in JEV infection. We found that during JEV infection, miRNA-155, miRNA-29b, miRNA-15b, miRNA-146a, miRNA-125b-5p, miRNA-30la, miRNA-19b-3p, and miRNA-124, cause upregulation of human genes whereas miRNA-432, miRNA-370, miRNA- 33a-5p, and miRNA-466d-3p are responsible for downregulation of human genes respectively. Further, these miRNAs are also responsible for the inflammatory effects. Although several other miRNAs critical to the JEV life cycle are yet unknown, there is currently no evidence for the role of miRNAs in persistence.

CAFs-derived rho-associated kinase1 mediated EMT to promote laryngeal squamous cell carcinoma metastasis

BACKGROUND

Cancer-associated fibroblasts (CAFs) play an essential role in tumorigenesis and development of cancers. Nevertheless, the specific molecular mechanism of tumorigenesis and development in Laryngeal squamous cell carcinoma (LSCC) still unknown.

METHODS

CAFs, CPFs and NFs were isolated and identified from laryngeal cancer, para-laryngeal cancer and normal tissues. Immunofluorescent staining, Rt-PCR and Western Blot were used to detect the expression of related proteins. Wound healing, migration, invasion and animal experiments were used to examine the ability of movement, migration, invasion and metastasis of LSCC.

RESULTS

ROCK1, was highly expressed in CAFs and CAFs enhanced LSCC metastasis in vivo and vitro, and downregulation of ROCK1 in CAFs inhibited the migration and invasion of LSCC cells. While increasing ROCK1 expression in NFs promoted the migration and invasion of LSCC cells. Further studies revealed that epithelial-mesenchymal transition (EMT) and JAK2/STAT3/ERK1/2 pathway might play an essential role in promoting metastasis of LSCC. In addition, inhibition activity of ROCK1 or JAK2/STAT3/ERK1/2 signal molecules significantly reduced EMT and metastasis.

CONCLUSIONS

CAFs-derived ROCK1 via JAK2/STAT3/ERK1/2 axis mediated EMT to promote LSCC metastasis and targeting ROCK1 might provide a potential treatment strategy for LSCC.

MicroRNA expression profiling of endocrine sensitive and resistant breast cancer cell lines

Background

Methods

Results

Conclusions

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Around 50–60% of microRNAs were significantly differentially expressed between ER- and ER + breast cancer cell lines.

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Transfection of miR-200c-3p mimic into ER -ve cells induced MET and reduced cell motility.

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Transfecting of miR-449a inhibitor into ER -ve cells reduced cell invasion but did not induce EMT.

Elevated Expression of JMJD5 Protein Due to Decreased miR-3656 Levels Contributes to Cancer Stem Cell-like Phenotypes under Overexpression of Cancer Upregulated Gene 2

Overexpression of cancer upregulated gene (CUG) 2 induces cancer stem cell-like phenotypes, such as enhanced epithelial-mesenchymal transition, sphere formation, and doxorubicin resistance. However, the precise mechanism of CUG2-induced oncogenesis remains unknown. We evaluated the effects of overexpression of CUG2 on microRNA levels using a microRNA microarray. Levels of miR-3656 were decreased when CUG2 was overexpressed; on the basis of this result, we further examined the target proteins of this microRNA. We focused on Jumonji C domain-containing protein 5 (JMJD5), as it has not been previously reported to be targeted by miR-3656. When CUG2 was overexpressed, JMJD5 expression was upregulated compared to that in control cells. A 3′ untranslated region (UTR) assay revealed that an miR-3656 mimic targeted the JMJD5 3′UTR, but the miR-3656 mimic failed to target a mutant JMJD5 3′UTR, indicating that miR-3656 targets the JMJD5 transcript. Administration of the miR-3656 mimic decreased the protein levels of JMD5 according to Western blotting. Additionally, the miR-3656 mimic decreased CUG2-induced cell migration, evasion, and sphere formation and sensitized the cells to doxorubicin. Suppression of JMJD5, with its small interfering RNA, impeded CUG2-induced cancer stem cell-like phenotypes. Thus, overexpression of CUG2 decreases miR-3656 levels, leading to upregulation of JMJD5, eventually contributing to cancer stem cell-like phenotypes.

The ubiquitin E3 ligase ARIH1 regulates hnRNP E1 protein stability, EMT and breast cancer progression

The epithelial to mesenchymal transition (EMT), a process that is aberrantly activated in cancer and facilitates metastasis to distant organs, requires coordinated transcriptional and post-transcriptional control of gene expression. The tumor-suppressive RNA binding protein, hnRNP-E1, regulates splicing and translation of EMT-associated transcripts and it is thought that it plays a major role in the control of epithelial cell plasticity during cancer progression. We have utilized yeast 2 hybrid screening to identify novel hnRNP-E1 interactors that play a role in regulating hnRNP-E1; this approach led to the identification of the E3 ubiquitin ligase ARIH1. Here, we demonstrate that hnRNP-E1 protein stability is increased upon ARIH1 silencing, whereas, overexpression of ARIH1 leads to a reduction in hnRNP-E1. Reduced ubiquitination of hnRNP-E1 detected in ARIH1 knockdown (KD) cells compared to control suggests a role for ARIH1 in hnRNP-E1 degradation. The identification of hnRNP-E1 as a candidate substrate of ARIH1 led to the characterization of a novel function for this ubiquitin ligase in EMT induction and cancer progression. We demonstrate a delayed induction of EMT and reduced invasion in mammary epithelial cells silenced for ARIH1. Conversely, ARIH1 overexpression promoted EMT induction and invasion. ARIH1 silencing in breast cancer cells significantly attenuated cancer cell stemness in vitro and tumor formation in vivo. Finally, we utilized miniTurboID proximity labeling to identify novel ARIH1 interactors that may contribute to ARIH1's function in EMT induction and cancer progression.

miR-205-5p Downregulation and ZEB1 Upregulation Characterize the Disseminated Tumor Cells in Patients with Invasive Ductal Breast Cancer

Background: Dissemination of breast cancer (BC) cells through the hematogenous or lymphogenous vessels leads to metastatic disease in one-third of BC patients. Therefore, we investigated the new prognostic features for invasion and metastasis. Methods: We evaluated the expression of miRNAs and epithelial-to-mesenchymal transition (EMT) genes in relation to CDH1/E-cadherin changes in samples from 31 patients with invasive ductal BC including tumor centrum (TU-C), tumor invasive front (TU-IF), lymph node metastasis (LNM), and CD45-depleted blood (CD45-DB). Expression of miRNA and mRNA was quantified by RT-PCR arrays and associations with clinico-pathological characteristics were statistically evaluated by univariate and multivariate analysis. Results: We did not verify CDH1 regulating associations previously described in cell lines. However, we did detect extremely high ZEB1 expression in LNMs from patients with distant metastasis, but without regulation by miR-205-5p. Considering the ZEB1 functions, this overexpression indicates enhancement of metastatic potential of lymphogenously disseminated BC cells. In CD45-DB samples, downregulated miR-205-5p was found in those expressing epithelial and/or mesenchymal markers (CTC+) that could contribute to insusceptibility and survival of hematogenously disseminated BC cells mediated by increased expression of several targets including ZEB1. Conclusions: miR-205-5p and potentially ZEB1 gene are promising candidates for markers of metastatic potential in ductal BC.

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.

Tumor Suppressive Effects of miR-124 and Its Function in Neuronal Development

MicroRNA-124 (miR-124) is strongly expressed in neurons, and its expression increases as neurons mature. Through DNA methylation in the miR-124 promoter region and adsorption of miR-124 by non-coding RNAs, miR-124 expression is known to be reduced in many cancer cells, especially with high malignancy. Recently, numerous studies have focused on miR-124 due to its promising tumor-suppressive effects; however, the overview of their results is unclear. We surveyed the tumor-suppressive effect of miR-124 in glial cell lineage cancers, which are the most frequently reported cancer types involving miR-124, and in lung, colon, liver, stomach, and breast cancers, which are the top five causes of cancer death. Reportedly, miR-124 not only inhibits proliferation and accelerates apoptosis, but also comprehensively suppresses tumor malignant transformation. Moreover, we found that miR-124 exerts its anti-tumor effects by regulating a wide range of target genes, most notably STAT3 and EZH2. In addition, when compared to the original role of miR-124 in neuronal development, we found that the miR-124 target genes that contribute to neuronal maturation share similarities with genes that cause cancer cell metastasis and epithelial-mesenchymal transition. We believe that the two apparently unrelated fields, cancer and neuronal development, can bring new discoveries to each other through the study of miR-124.

CircRNA VIM silence synergizes with sevoflurane to inhibit immune escape and multiple oncogenic activities of esophageal cancer by simultaneously regulating miR-124/PD-L1 axis

BACKGROUND

Circular RNA of vimentin (circ-VIM) is a predictor for poor prognosis of acute myeloid leukemia, but we had little information on its function in esophageal cancer (EC). Here we examined the effects of circ-VIM together with sevoflurane on immune escape and multiple oncogenic activities of EC.

METHODS

Bioinformatic tools, luciferase assay, and RNA immunoprecipitation were used to examine regulations between circ-VIM, miR-124-3p (miR-124), and PD-L1. CCK-8, wound healing, and Transwell assays were used to measure cell proliferation, migration, and invasion, respectively. The impacts of EC cells on cytotoxicity, proliferation, and apoptosis of CD8⁺ T cells were examined using LDH assay, CFSE staining, and Annexin V/PI staining, respectively. The in vivo tumorigenesis and lung metastases were assessed using xenograft model and tail vein injection of EC cells.

RESULTS

Significant upregulation of circ-VIM and PD-L1 and downregulation of miR-124 were detected in EC tissues or cells. Circ-VIM sponged miR-124 and released its suppression on the downstream target PD-L1. Sevoflurane, independent of circ-VIM, also upregulated miR-124 to lower PD-L1 expression. By modulating miR-124/PD-L1 axis, silencing circ-VIM and applying sevoflurane both inhibited immune escape and multiple oncogenic activities of EC in vitro, and suppressed xenograft growth and lung metastases in vivo. The inactivation of Ras/ERK signaling pathway was involved in suppression of malignant phenotypes by silencing circ-VIM and sevoflurane treatment.

CONCLUSIONS

Silencing circ-VIM and applying sevoflurane, by separately regulating miR-124/PD-L1 axis, presented synergistic effects in inhibiting immune escape and multiple malignant phenotypes of EC cells.

What we can learn from embryos to understand the mesenchymal-to-epithelial transition in tumor progression

Epithelial plasticity involved the terminal and transitional stages that occur during epithelial-to-mesenchymal transition (EMT) and mesenchymal-to-epithelial transition (MET), both are essential at different stages of early embryonic development that have been co-opted by cancer cells to undergo tumor metastasis. These processes are regulated at multiple instances, whereas the post-transcriptional regulation of key genes mediated by microRNAs is gaining major attention as a common and conserved pathway. In this review, we focus on discussing the latest findings of the cellular and molecular basis of the less characterized process of MET during embryonic development, with special attention to the role of microRNAs. Although we take in consideration the necessity of being cautious when extrapolating the obtained evidence, we propose some commonalities between early embryonic development and cancer progression that can shed light into our current understanding of this complex event and might aid in the design of specific therapeutic approaches.

Activation of GPER by E2 promotes proliferation, invasion and migration of breast cancer cells by regulating the miR-124/CD151 pathway

Breast cancer is one of the most common malignancies worldwide and is responsible for a high mortality rate. However, the underlying pathological mechanism of breast cancer remains unclear. MicroRNAs (miRNAs/miRs) play critical roles in the progression of breast cancer. Recent studies have reported that miR-124/CD151 participates in the development of breast cancer. However, the exact molecular mechanism of miR-124/CD151 action in 17β-estradiol (E2)-treated breast cancer cells remains unknown. Thus, the present study aimed to investigate miR-124 and CD151 expression levels in MCF-7 cells treated with E2 via reverse transcription-quantitative PCR and western blot analyses. Bioinformatic analysis was performed to predict and identify whether CD151 is a potential target of miR-124. The Cell Counting Kit-8 and colony formation assays were performed to detect proliferation of MCF-7 cells. In addition, the invasive and migratory abilities of MCF-7 cells were assessed via the Transwell and wound healing assays, respectively. The results demonstrated that E2 downregulated miR-124 expression, while upregulating G protein -coupled estrogen receptor (GPER) expression in MCF-7 cells. Following treatment with the GPER antagonist, G15, miR-124 expression was significantly enhanced and E2-induced proliferation, invasion and migration of MCF-7 cells were notably inhibited. In addition, CD151 was confirmed as a direct target of miR-124. CD151 silencing remarkably suppressed the proliferation, invasion and migration of E2-induced MCF-7 cells. Taken together, these results suggest that upregulation of GPER expression induced by E2 promotes proliferation, invasion and migration of breast cancer cells by regulating the miR-124/CD151 pathway. Thus, the results of the present study provide a potential novel method for the treatment and prognosis of breast cancer.

MicroRNA124 and microRNA21-5p regulate migration, proliferation and differentiation of rat bone marrow mesenchymal stem cells

Mesenchymal stem cells (MSCs) are multipotent stromal cells that can be a useful source of cells for the treatment of many diseases, including neurologic diseases. The curative effect of MSCs relies mostly on cell’s capacity of migration, proliferation and differentiation. MicroRNAs (miRNAs) are small non-coding RNAs that play important roles on regulating various cell behaviors. Here, we report that miRNA-124 (miR124) and miRNA-21-5p (miR21-5p) display different regulatory roles on migration, proliferation and neuron differentiation of MSCs. MiR124 was shown greatly promoting MSCs migration and neuronal differentiation. MiR21-5p could significantly enhance the proliferation and neuronal differentiation ability of MSCs. MiR124 and miR21-5p synergistically promote differentiation of MSCs into neurons. Collectively, miR124 and miR21-5p can functionally regulate cell migration, proliferation and neuronal differentiation of MSCs. Therefore, miR124 and miR21-5p may be promising tools to improve transplantation efficiency for neural injury.

Involvement of microRNA in Solid Cancer: Role and Regulatory Mechanisms

MicroRNAs (miRNAs) function as the post-transcriptional factor that finetunes the gene expression by targeting to the specific candidate. Mis-regulated expression of miRNAs consequently disturbs gene expression profile, which serves as the pivotal mechanism involved in initiation or progression of human malignancy. Cancer-relevant miRNA is potentially considered the therapeutic target or biomarker toward the precise treatment of cancer. Nevertheless, the regulatory mechanism underlying the altered expression of miRNA in cancer is largely uncovered. Detailed knowledge regarding the influence of miRNAs on solid cancer is critical for exploring its potential of clinical application. Herein, we elucidate the regulatory mechanism regarding how miRNA expression is manipulated and its impact on the pathogenesis of distinct solid cancer.

Regulation of breast cancer metastasis signaling by miRNAs

Despite the decline in death rate from breast cancer and recent advances in targeted therapies and combinations for the treatment of metastatic disease, metastatic breast cancer remains the second leading cause of cancer-associated death in U.S. women. The invasion-metastasis cascade involves a number of steps and multitudes of proteins and signaling molecules. The pathways include invasion, intravasation, circulation, extravasation, infiltration into a distant site to form a metastatic niche, and micrometastasis formation in a new environment. Each of these processes is regulated by changes in gene expression. Noncoding RNAs including microRNAs (miRNAs) are involved in breast cancer tumorigenesis, progression, and metastasis by post-transcriptional regulation of target gene expression. miRNAs can stimulate oncogenesis (oncomiRs), inhibit tumor growth (tumor suppressors or miRsupps), and regulate gene targets in metastasis (metastamiRs). The goal of this review is to summarize some of the key miRNAs that regulate genes and pathways involved in metastatic breast cancer with an emphasis on estrogen receptor α (ERα+) breast cancer. We reviewed the identity, regulation, human breast tumor expression, and reported prognostic significance of miRNAs that have been documented to directly target key genes in pathways, including epithelial-to-mesenchymal transition (EMT) contributing to the metastatic cascade. We critically evaluated the evidence for metastamiRs and their targets and miRNA regulation of metastasis suppressor genes in breast cancer progression and metastasis. It is clear that our understanding of miRNA regulation of targets in metastasis is incomplete.

Unravelling Structure, Localization, and Genetic Crosstalk of KLF3 in Human Breast Cancer

Breast cancer is the most prevailing disease among women. It actually develops from breast tissue and has heterogeneous and complex nature that constitutes multiple tumor quiddities. These features are associated with different histological forms, distinctive biological characteristics, and clinical patterns. The predisposition of breast cancer has been attributed to a number of genetic factors, associated with the worst outcomes. Unfortunately, their behavior with relevance to clinical significance remained poorly understood. So, there is a need to further explore the nature of the disease at the transcriptome level. The focus of this study was to explore the influence of Krüppel-like factor 3 (KLF3), tumor protein D52 (TPD52), microRNA 124 (miR-124), and protein kinase C epsilon (PKCε) expression on breast cancer. Moreover, this study was also aimed at predicting the tertiary structure of KLF3 protein. Expression of genes was analyzed through real-time PCR using the delta cycle threshold method, and statistical significance was calculated by two-way ANOVA in Graphpad Prism. For the construction of a 3D model, various bioinformatics software programs, Swiss Model and UCSF Chimera, were employed. The expression of KLF3, miR-124, and PKCε genes was decreased (fold change: 0.076443, 0.06969, and 0.011597, respectively). However, there was 2-fold increased expression of TPD52 with p value < 0.001 relative to control. Tertiary structure of KLF3 exhibited 80.72% structure conservation with its template KLF4 and was 95.06% structurally favored by a Ramachandran plot. These genes might be predictors of stage, metastasis, receptor, and treatment status and used as new biomarkers for breast cancer diagnosis. However, extensive investigations at the tissue level and in in vivo are required to further strengthen their role as a potential biomarker for prognosis of breast cancer.

A multi-omics study on cutaneous and uveal melanoma

AIM

To present the multi-omics landscape of cutaneous melanoma (CM) and uveal melanoma (UM) from The Cancer Genome Atlas (TCGA).

METHODS

The differentially expressed genes (DEGs) between CM and UM were found and integrated into a gene ontology enrichment analysis. Besides, the differentially expressed miRNAs were also identified. We also compared the methylation level of CM with UM and identified the differentially methylated regions to integrate with the DEGs to display the relationship between the gene expression and DNA methylation. The differentially expressed transcription factors (TFs) were identified.

RESULTS

Though CM had more mutational burden than UM, they shared several similarities such as the same rankings in diverse variant types. Except GNAQ and GNA11, the other top 18 mutated genes of the combined group were mostly detected in CM instead of UM. On the transcriptomic level, 4610 DEGs were found and integrated into a gene ontology enrichment analysis. We also identified 485 differentially expressed miRNAs. The methylation analysis showed that UM had a significantly higher methylation level than CM. The integration of differentially methylated regions and DEGs demonstrated that most DEGs were downregulated in UM and the hypo- and hypermethylation presented no obvious difference within these DEGs. Finally, 116 hypermethylated TFs and 114 hypomethylated TFs were identified as differentially expressed TFs in CM when compared with UM.

CONCLUSION

This multi-omics study on comparing CM with UM confirms that they differ in all analyzed levels. Of notice, the results also offer new insights with implications for elucidating certain unclear problems such as the distinct role of epithelial mesenchymal transition in two melanomas, the different metastatic routes of CM and UM and the liver tropism of metastatic UM.

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

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

MicroRNA-124-3p Plays a Crucial Role in Cleft Palate Induced by Retinoic Acid

Cleft lip with/without cleft palate (CL/P) is one of the most common congenital birth defects, showing the complexity of both genetic and environmental contributions [e.g., maternal exposure to alcohol, cigarette, and retinoic acid (RA)] in humans. Recent studies suggest that epigenetic factors, including microRNAs (miRs), are altered by various environmental factors. In this study, to investigate whether and how miRs are involved in cleft palate (CP) induced by excessive intake of all-trans RA (atRA), we evaluated top 10 candidate miRs, which were selected through our bioinformatic analyses, in mouse embryonic palatal mesenchymal (MEPM) cells as well as in mouse embryos treated with atRA. Among them, overexpression of miR-27a-3p, miR-27b-3p, and miR-124-3p resulted in the significant reduction of cell proliferation in MEPM cells through the downregulation of CP-associated genes. Notably, we found that excessive atRA upregulated the expression of miR-124-3p, but not of miR-27a-3p and miR-27b-3p, in both in vivo and in vitro. Importantly, treatment with a specific inhibitor for miR-124-3p restored decreased cell proliferation through the normalization of target gene expression in atRA-treated MEPM cells and atRA-exposed mouse embryos, resulting in the rescue of CP in mice. Taken together, our results indicate that atRA causes CP through the induction of miR-124-3p in mice.

Circulating MicroRNAs and Blood-Brain-Barrier Function in Breast Cancer Metastasis

Brain metastases are a major cause of death in breast cancer patients. A key event in the metastatic progression of breast cancer in the brain is the migration of cancer cells across the blood-brain barrier (BBB). The BBB is a natural barrier with specialized functions that protect the brain from harmful substances, including anti-tumor drugs. Extracellular vesicles (EVs) sequestered by cells are mediators of cell-cell communication. EVs carry cellular components, including microRNAs that affect the cellular processes of target cells. Here, we summarize the knowledge about microRNAs known to play a significant role in breast cancer and/or in the BBB function. In addition, we describe previously established in vitro BBB models, which are a useful tool for studying molecular mechanisms involved in the formation of brain metastases.

Scratch2, a Snail Superfamily Member, Is Regulated by miR-125b

Scratch2 is a transcription factor expressed in a very restricted population of vertebrate embryonic neural cell precursors involved in their survival, differentiation, and migration. The mechanisms that control its expression remain unknown and could contribute towards our understanding of gene regulation during neural differentiation and evolution. Here we investigate the role of microRNAs (miRNAs) in the Scrt2 post-transcriptional regulatory mechanism. We identified binding sites for miR-125b and -200b in the Scrt2 3′UTR in silico. We confirmed the repressive-mediated activity of the Scrt2 3′UTR through electroporation of luciferase constructs into chick embryos. Further, both CRISPR/Cas9-mediated deletion of miR-125b/-200b responsive elements from chicken Scrt2 3′UTR and expression of miRNAs sponges increased Scrt2 expression field, suggesting a role for these miRNAs as post-transcriptional regulators of Scrt2. The biological effect of miR-125b titration was much more pronounced than that of miR-200b. Therefore, we propose that, after transcription, miR-125b fine-tunes the Scrt2 expression domain.

MiR-128 suppresses metastatic capacity by targeting metadherin in breast cancer cells

Background

Breast cancer, the most common cancer in women worldwide, causes the vast majority of cancer-related deaths. Undoubtedly, tumor metastasis and recurrence are responsible for more than 90 percent of these deaths. MicroRNAs are endogenous noncoding RNAs that have been integrated into almost all the physiological and pathological processes, including metastasis. In the present study, the role of miR-128 in breast cancer was investigated.

Results

Compared to the corresponding adjacent normal tissue, the expression of miR-128 was significantly suppressed in human breast cancer specimens. More importantly, its expression level was reversely correlated to histological grade of the cancer. Ectopic expression of miR-128 in the aggressive breast cancer cell line MDA-MB-231 could inhibit cell motility and invasive capacity remarkably. Afterwards, Metadherin (MTDH), also known as AEG-1 (Astrocyte Elevated Gene 1) and Lyric that implicated in various aspects of cancer progression and metastasis, was further identified as a direct target gene of miR-128 and its expression level was up-regulated in clinical samples as expected. Moreover, knockdown of MTDH in MDA-MB-231 cells obviously impaired the migration and invasion capabilities, whereas re-expression of MTDH abrogated the suppressive effect caused by miR-128.

Conclusions

Overall, these findings demonstrate that miR-128 could serve as a novel biomarker for breast cancer metastasis and a potent target for treatment in the future.

Anti-cancer effect of miR-139-3p on laryngeal squamous cell carcinoma by targeting rab5a: In vitro and in vivo studies

BACKGROUND

Laryngeal squamous cell carcinoma is the second most common head and neck squamous cell carcinoma. Nowadays, as traditional treatment methods are gradually limited, the development of new treatment methods needs to be resolved. This study aimed to investigate the role of microRNA(miR)-139-3p in laryngeal squamous cell carcinoma, and further explored the underlying mechanism.

METHODS

In this study, we first used quantitative real time polymerase chain reaction (qRT-PCR) to detect the level of miR-139-3p in laryngeal squamous cell carcinoma tissue. Then, TargetScan and dual luciferase reporter assay were used to explore and verify whether rab5a was a direct target of miR-139-3p. Thereafter, the expression of miR-139-3p and rab5a in laryngeal squamous cell carcinoma cell line SNU46 was changed by transfection with miR-139-3p mimic or rab5a-plasmid. Then, SNU46 cell proliferation, cell apoptosis, cell cycle, cell migration and cell invasion were determined using Cell Counting Kit-8 (CCK-8), flow cytometry, scratch assay and Transwell assay, respectively. Finally, mouse tumor formation experiments were used to test whether miR-139-3p still exerted its role in inhibiting laryngeal squamous cell carcinoma in vivo.

RESULTS

Compared with the adjacent normal tissues, miR-139-3p significantly down-regulated in laryngeal squamous cell carcinoma tissue. It was confirmed by dual luciferase reporter experiment that rab5a was a direct target of miR-139-3p. Moreover, the up-regulation of miR-139-3p could effectively inhibit the proliferation, migration and invasion of laryngeal squamous cell carcinoma cells, and induced cell cycle arrest and apoptosis. In the molecular level study, we found that up-regulation of miR-139-3p inhibited the expression of rab5a in SNU46 cells. In addition, the protein and mRNA expression of factors related to cell migration, invasion, proliferation and apoptosis, such as integrin β1, Focal adhesion kinase (FAK), paxillin, B cell lymphoma-2 (bcl-2), nuclear factor-kappaB (NF-κB), vascular endothelial growth factor (VEGF), matrix metalloproteinase 9 (MMP9), in SNU46 cells were changed after miR-139-3p up-regulation. Consistent with the results of in vitro studies, in vivo experiments showed that miR-139-3p mimic inhibited laryngeal squamous cell carcinoma tumor growth. All the effects of miR-139-3p on laryngeal squamous cell carcinoma were reversed by rab5a over-expression.

CONCLUSION

miR-139-3p could inhibit laryngeal squamous cell carcinoma by targeting rab5a both in vitro and in vivo.

Epithelial-to-mesenchymal transition markers are differentially expressed in epithelial cancer cell lines after everolimus treatment

The epithelial-to-mesenchymal transition (EMT) is a phenomenon during which cancer epithelial cells undergo changes in plasticity and lose cell-cell adhesion with consequent remodeling of the extracellular matrix and development of mesenchymal characteristics. Long non-coding RNAs (lncRNAs) have been described as EMT modulation markers, becoming a promising target in the development of new therapies for cancer. The present study aimed to investigate the role of everolimus at 100 nM as inductor of the EMT phenomenon in cell lines derived from human breast (BT-549), colorectal (RKO-AS45-1) and ovary (TOV-21G) cancer. The integrity of cellular junctions was monitored using an in vitro model of epithelial resistance. The results demonstrated that the EMT genes ZEB1, TWIST1 and TGFB1 were differentially expressed in cells treated with everolimus compared with in untreated cells. lncRNA HOTAIR was upregulated post-treatment only in BT-549 cells compared with in untreated cells. After treatment with everolimus, the intensity of fluorescence of P-cadherin decreased, and that of fibronectin increased in RKO-AS45-1 and TOV-21G cells compared with control cells. The transepithelial electrical resistance at the RKO-AS45-1 monolayer treated with everolimus started to decrease at 48 h. The changes in the gene expression and epithelial resistance may confirm the role of everolimus in EMT.

Detection of microRNA expression levels based on microarray analysis for classification of idiopathic pulmonary fibrosis

The etiology and pathophysiological mechanisms of idiopathic pulmonary fibrosis (IPF) are yet to be fully elucidated; however, mining of disease-related microRNAs (miRNAs/miRs) has improved the understanding of the progression of IPF. The aim of the current study was to screen miRNAs associated with IPF using three mathematical algorithms: One-way ANOVA, least absolute shrinkage and selector operation (LASSO) and support vector machine-recursive feature elimination (SVM-RFE). Using ANOVA, three miRNAs and two miRNAs were selected with opposite expression patterns in moderate and severe IPF, respectively. In total, two algorithms, LASSO and SVM-RFE, were used to perform feature selection of miRNAs. miRNAs from patients were also extracted from formalin-fixed paraffin-embedded tissues and detected using reverse transcription-quantitative PCR (RT-qPCR). The intersection of the three algorithms (ANOVA, LASSO and SVM-RFE) was taken as the final result of the miRNA candidates. Three miRNA candidates, including miR-124, hsa-miR-524-5p and hsa-miR-194 were therefore used as biomarkers. The receiver operating characteristic model demonstrated favorable discrimination between IPF and control groups, with an area under the curve of 78.5%. Moreover, RT-qPCR results indicated that miR-124, hsa-miR-524-5p, hsa-miR-194 and hsa-miR-133a were differentially expressed between patients with IPF and age-matched men without fibrotic lung disease. The target genes of these miRNAs were further predicted and Kyoto Encyclopedia of Genes and Genomes enrichment analysis was performed. Collectively, the present results suggested that the identified miRNAs associated with IPF may be useful biomarkers for the diagnosis of this disease.

microRNA-124 inhibits stem-like properties and enhances radiosensitivity in nasopharyngeal carcinoma cells via direct repression of expression of JAMA

Cancer stem cells (CSCs) are a source of tumour recurrence in patients with nasopharyngeal carcinoma (NPC); however, the function of microRNA‐124 (miR‐124) in NPC CSCs has not been clearly defined. In this study, we investigated the role of miR‐124 in NPC CSCs. qRT‐PCR was performed to measure miR‐124 expression in NPC tissues and cell lines and the effects of miR‐124 on stem‐like properties and radiosensitivity of NPC cells measured. Luciferase reporter assays and rescue experiments were used to investigate the interaction of miR‐124 with the 3′UTR of junctional adhesion molecule A (JAMA). Finally, we examined the effects of miR‐124 in an animal model and clinical samples. Down‐regulation of miR‐124 was detected in cancer tissues and was inversely associated with tumour stage and lymph node metastasis. Overexpression of miR‐124 inhibited stemness properties and enhanced radiosensitivity of NPC cells in vitro and in vivo via targeting JAMA. Up‐regulation of miR‐124 was correlated with superior overall survival of patients with NPC. Our study demonstrates that miR‐124 can inhibit stem‐like properties and enhance radiosensitivity by directly targeting JAMA in NPC. These findings provide novel insights into the molecular mechanisms underlying therapy failure in NPC.

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.

A Slug-dependent mechanism is responsible for tumor suppression of p53-stabilizing compound CP-31398 in p53-mutated endometrial carcinoma

Mutation in the tumor suppressor gene p53 is the most frequent molecular defect in endometrial carcinoma (EC). Recently, CP-31398, a p53-stabilizing compound, has been indicated to possess the ability to alter the expression of non-p53 target genes in addition to p53 downstream genes in tumor cells. Herein, we explore the alternative mechanisms underlying the restoration of EC tumor suppressor function in mutant p53 by CP-31398. A p53-mutated EC cell was constructed in AN3CA cells with restored or partial loss of Slug using lentiviral vectors, followed by treatment with 25 μM CP-31398. A p53-independent mechanism of CP-31398 was confirmed by the interaction between mouse double minute 2 homolog (MDM2) and Slug AN3CA cells treated with IWR-1 (inhibitor of Wnt response 1). Furthermore, the AN3CA cells were treated with short hairpin RNA against Slug, Wnt-specific activators (LiCl) or inhibitors (XAV-939) followed by CP-31398 treatment. Moreover, AN3CA cell proliferation and apoptosis were examined. A tumorigenicity assay was conducted in nude mice. CP-31398 could promote the apoptosis of p53-mutated EC cells, while Slug reversed this effect. Slug ubiquitination was found to occur via binding of Slug to MDM2 in AN3CA cells. We found that CP-31398 increased the GSK-3ß, p-Slug, Puma, Wtp53, and Bax expressions whereas Wnt, Mtp-53, Slug, Bcl-2, and Ki-67 expressions were decreased. However, these findings were reversed following the activation of the Wnt pathway and overexpression of Slug. Finally, the in vivo experimental evidence confirmed that CP-31398 with depleted Slug suppressed tumor growth by downregulating the Slug. Collectively, CP-31398-regulated Slug downregulation represses the p53-mutated EC via the p53/Wnt/Puma pathway.

Long Non-Coding RNA-NEAT1 Promotes Cell Migration and Invasion via Regulating miR-124/NF-κB Pathway in Cervical Cancer

Background

This study aimed to investigate the regulatory role of lncRNA-NEAT1 on cervical cancer (CC) and the underlying molecular mechanisms.

Methods

The expression of lncRNA-NEAT1 and miR-124 was detected in CC tissues and cells (HeLa and SiHa cells) by qRT-RCR. The relation between lncRNA-NEAT1 expression and clinical parameters of CC patients was explored. The cell migration and invasion were detected by wound healing assay and transwell assay. The cell proliferation was detected by CCK-8 and anchorage-independent colony assay. The targeting relation between miR-124 and lncRNA-NEAT1 was predicted by TargetScan and identified by dual luciferase reporter gene and RNA pull-down assay. The expression of metastasis- (MMP-2 and MMP), EMT- (E-cadherin, N-cadherin and Vimentin), and NF-κB pathway-related factors (NF-κB p65, p-NF-κB p65 and IκBα) was detected by Western blot.

Results

The expression of lncRNA-NEAT1 was upregulated in CC tissues and cells and positively correlated with TNM stage and lymph node metastasis. Overexpression of lncRNA-NEAT1 promoted the proliferation, migration and invasion, influenced the expression of EMT markers, and activated NF-κB pathway in HeLa and SiHa cells. Silencing of lncRNA-NEAT1 exhibited opposite effects on HeLa and SiHa cells. LncRNA-NEAT1 could negatively regulate its target miR-124. MiR-124 reversed the effects of lncRNA-NEAT1 on the migration, invasion, EMT and NF-κB pathway of HeLa cells.

Conclusion

LncRNA-NEAT1 promoted the migration and invasion of CC cells via regulating miR-124/NF-κB pathway.

miR-124 Intensified Oxaliplatin-Based Chemotherapy by Targeting CAPN2 in Colorectal Cancer

Our previous study demonstrated that miR-124 was downregulated in colorectal cancer (CRC) compared with normal mucosa, and the downregulated expression of miR-124 was an independent prognostic factor in CRC patients. However, the function of miR-124 in CRC patients treated with chemotherapy is currently unclear. The aim of this study was to determine the miR-124 expression and its regulative role in oxaliplatin (L-OHP)-based chemotherapy of CRC patients. We observed that low miR-124 expression was correlated with worse overall survival (OS) in the 220 patients who received postoperative chemotherapy of 5-fluorouracil [5-FU]+leucovorin+L-OHP (FOLFOX) or capecitabine+L-OHP (XELOX). miR-124 overexpression promoted L-OHP-induced, but not 5-FU-induced, cytotoxicity and apoptosis in HT29 and SW480 cells. CAPN2 was a direct target of miR-124, and its protein expression was reduced by forced expression of miR-124. miR-124 inhibited tumorigenesis and promoted OS of mice bearing xenograft tumors, especially upon L-OHP treatment. miR-124 also promoted L-OHP-induced apoptosis and restrained CAPN2 protein expression in xenograft tumors. Our results suggest that miR-124 could be considered as both a predictor of L-OHP-based chemotherapy for personalized treatment and a therapeutic target for CRC.

Denosumab inhibits MCF-7 cell line-induced spontaneous osteoclastogenesis via the RANKL/MALAT1/miR-124 axis

Background

Denosumab is an inhibitor of receptor activator of NF-κB ligand (RANKL), which inhibits bone metastasis (BM) in breast cancer (BC), but does not completely control cancer cell BM in some BC patients. This study was designed to study whether denosumab inhibits human BC cells (MCF-7) cell line-induced spontaneous osteoclastogenesis via RANKL/metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)/miR-124 axis.

Methods

We established a co-culture system of MCF-7-induced spontaneous osteoclastogenesis in RAW 264.7 cells, and denosumab is added into the co-culture system to inhibit RAW 264.7 cell differentiation into osteoclasts. Real-time PCR (RT-PCR), immunofluorescence and western blotting analysis were used to detect gene expression, while tartrate-resistant acid phosphatase (TRAP) staining was used to assess osteoclast formation.

Results

Denosumab inhibits MCF-7 cell line-induced spontaneous osteoclastogenesis, and the inhibition of denosumab was found to be more pronounced after MALAT1 downregulation and miR-124 overexpression. However, MALAT1 knockdown or miR-124 overexpression did not alter RANKL protein expression. Moreover, the dual luciferase gene reporter system showed that miR-124 targeted the inhibition of MALAT1, while si-MALAT1 upregulated miR-124 expression. miR-124-mimics were able to decrease the expression of Rab27a, IL-11, activated T-cell nuclear factor 1 (NFATc1) and TARP protein.

Conclusions

Denosumab inhibits MALAT1 expression by inhibiting RANKL, thereby upregulating miR-124 expression, which ultimately inhibits MCF-7 cell line-induced pseudo osteoclastogenesis.

Targeting P4HA1 with a Small Molecule Inhibitor in a Colorectal Cancer PDX Model

Deposition, remodeling, and signaling of the extracellular matrix facilitate tumor growth and metastasis. Here, we demonstrated that an enzyme, collagen prolyl 4-hydroxylase, alpha polypeptide I (P4HA1), which is involved in collagen synthesis and deposition, had elevated expression in colorectal cancers (CRCs) as compared to normal colonic tissues. The expression of P4HA1 in CRCs was independent of patient's age, race/ethnicity, gender, pathologic stage and grade, tumor location, and microsatellite instability (MSI) and p53 status. By modulating P4HA1 with shRNA, there was a reduction in malignant phenotypes of CRCs, including cell proliferation, colony formation, invasion, migration, and tumor growth, in mice regardless of their p53 and MSI status. Immunoblot analysis of excised xenograft tumors developed from cells with silenced PH4HA1 showed low levels of proliferating cell nuclear antigen. Further, in CRC mouse models, silencing of P4HA1 in HT29 cells resulted in less metastasis to liver and bone. P4HA1 expression was regulated by miR-124, and inhibition of cell growth was noted for CRC cells treated with miR-124. Furthermore, low levels of the transcriptional repressor EZH2 reduced P4HA1 expression in CRC cells. Inhibition of P4HA1 with the small molecule inhibitor diethyl-pythiDC decreased AGO2 and MMP1, which are P4HA1 target molecules, and reduced the malignant phenotypes of CRC cells. Treatment of CRC patient-derived xenografts that exhibit high expression of P4HA1 with diethyl-pythiDC resulted in tumor regression. Thus, the present study shows that P4HA1 contributes to CRC progression and metastasis and that targeting of P4HA1 with diethyl-pythiDC could be an effective therapeutic strategy for aggressive CRCs.

Regulatory Mechanism of MicroRNA Expression in Cancer

Altered gene expression is the primary molecular mechanism responsible for the pathological processes of human diseases, including cancer. MicroRNAs (miRNAs) are virtually involved at the post-transcriptional level and bind to 3' UTR of their target messenger RNA (mRNA) to suppress expression. Dysfunction of miRNAs disturbs expression of oncogenic or tumor-suppressive target genes, which is implicated in cancer pathogenesis. As such, a large number of miRNAs have been found to be downregulated or upregulated in human cancers and to function as oncomiRs or oncosuppressor miRs. Notably, the molecular mechanism underlying the dysregulation of miRNA expression in cancer has been recently uncovered. The genetic deletion or amplification and epigenetic methylation of miRNA genomic loci and the transcription factor-mediated regulation of primary miRNA often alter the landscape of miRNA expression in cancer. Dysregulation of the multiple processing steps in mature miRNA biogenesis can also cause alterations in miRNA expression in cancer. Detailed knowledge of the regulatory mechanism of miRNAs in cancer is essential for understanding its physiological role and the implications of cancer-associated dysfunction and dysregulation. In this review, we elucidate how miRNA expression is deregulated in cancer, paying particular attention to the cancer-associated transcriptional and post-transcriptional factors that execute miRNA programs.

Emerging molecular functions of microRNA-124: Cancer pathology and therapeutic implications

MicroRNAs are characterized as small, single-stranded, non-coding RNA molecules that bind to their target mRNA to prevent protein synthesis. MicroRNAs regulate various normal processes; however, they are aberrantly regulated in many cancers. They control the expression of various genes, including cancer-related genes. This causes microRNAs to be considered as a good target for further investigations for designing novel therapeutic strategies. Since miR124 is known for some time already, it has a tumor-suppressing role in various cancers. Numerous studies indicate its definite roles in malignant processes such as epithelial-to-mesenchymal transition, cell cycle arrest, metastasis, cancer stem cell formation and induction of apoptosis. However, some studies have indicated a dual role for miR-124 in oncogenic processes like autophagy and multi-drug resistance. In this article, we will review recent researches on the biological functions and clinical implications of miR-124. Subsequently, we will discuss future perspectives in terms of the roles of this miRNA in cancers.

Interplay among SNAIL Transcription Factor, MicroRNAs, Long Non-Coding RNAs, and Circular RNAs in the Regulation of Tumor Growth and Metastasis

SNAIL (SNAI1) is a zinc finger transcription factor that binds to E-box sequences and regulates the expression of genes. It usually acts as a gene repressor, but it may also activate the expression of genes. SNAIL plays a key role in the regulation of epithelial to mesenchymal transition, which is the main mechanism responsible for the progression and metastasis of epithelial tumors. Nevertheless, it also regulates different processes that are responsible for tumor growth, such as the activity of cancer stem cells, the control of cell metabolism, and the regulation of differentiation. Different proteins and microRNAs may regulate the SNAIL level, and SNAIL may be an important regulator of microRNA expression as well. The interplay among SNAIL, microRNAs, long non-coding RNAs, and circular RNAs is a key event in the regulation of tumor growth and metastasis. This review for the first time discusses different types of regulation between SNAIL and non-coding RNAs with a focus on feedback loops and the role of competitive RNA. Understanding these mechanisms may help develop novel therapeutic strategies against cancer based on microRNAs.

Molecular regulation of Snai2 in development and disease

The transcription factor Snai2, encoded by the SNAI2 gene, is an evolutionarily conserved C2H2 zinc finger protein that orchestrates biological processes critical to tissue development and tumorigenesis. Initially characterized as a prototypical epithelial-to-mesenchymal transition (EMT) transcription factor, Snai2 has been shown more recently to participate in a wider variety of biological processes, including tumor metastasis, stem and/or progenitor cell biology, cellular differentiation, vascular remodeling and DNA damage repair. The main role of Snai2 in controlling such processes involves facilitating the epigenetic regulation of transcriptional programs, and, as such, its dysregulation manifests in developmental defects, disruption of tissue homeostasis, and other disease conditions. Here, we discuss our current understanding of the molecular mechanisms regulating Snai2 expression, abundance and activity. In addition, we outline how these mechanisms contribute to disease phenotypes or how they may impact rational therapeutic targeting of Snai2 dysregulation in human disease.

Therapeutic Inducers of Apoptosis in Ovarian Cancer

Ovarian cancers remain one of the most common causes of gynecologic cancer-related death in women worldwide. The standard treatment comprises platinum-based chemotherapy, and most tumors develop resistance to therapeutic drugs. One mechanism of developing drug resistance is alterations of molecules involved in apoptosis, ultimately assisting in the cells' capability to evade death. Thus, there is a need to focus on identifying potential drugs that restore apoptosis in cancer cells. Here, we discuss the major inducers of apoptosis mediated through various mechanisms and their usefulness as potential future treatment options for ovarian cancer. Broadly, they can target the apoptotic pathways directly or affect apoptosis indirectly through major cancer-pathways in cells. The direct apoptotic targets include the Bcl-2 family of proteins and the inhibitor of apoptotic proteins (IAPs). However, indirect targets include processes related to homologous recombination DNA repair, micro-RNA, and p53 mutation. Besides, apoptosis inducers may also disturb major pathways converging into apoptotic signals including janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3), wingless-related integration site (Wnt)/β-Catenin, mesenchymal-epithelial transition factor (MET)/hepatocyte growth factor (HGF), mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK), and phosphatidylinositol 3-kinase (PI3K)/v-AKT murine thymoma viral oncogene homologue (AKT)/mammalian target of rapamycin (mTOR) pathways. Several drugs in our review are undergoing clinical trials, for example, birinapant, DEBIO-1143, Alisertib, and other small molecules are in preclinical investigations showing promising results in combination with chemotherapy. Molecules that exhibit better efficacy in the treatment of chemo-resistant cancer cells are of interest but require more extensive preclinical and clinical evaluation.

MicroRNAs Contribute to Breast Cancer Invasiveness

Cancer statistics in 2018 highlight an 8.6 million incidence in female cancers, and 4.2 million cancer deaths globally. Moreover, breast cancer is the most frequent malignancy in females and twenty percent of these develop metastasis. This provides only a small chance for successful therapy, and identification of new molecular markers for the diagnosis and prognostic prediction of metastatic disease and development of innovative therapeutic molecules are therefore urgently required. Differentially expressed microRNAs (miRNAs) in cancers cause multiple changes in the expression of the tumorigenesis-promoting genes which have mostly been investigated in breast cancers. Herein, we summarize recent data on breast cancer-specific miRNA expression profiles and their participation in regulating invasive processes, in association with changes in cytoskeletal structure, cell-cell adhesion junctions, cancer cell-extracellular matrix interactions, tumor microenvironments, epithelial-to-mesenchymal transitions and cancer cell stem abilities. We then focused on the epigenetic regulation of individual miRNAs and their modified interactions with other regulatory genes, and reviewed the function of miRNA isoforms and exosome-mediated miRNA transfer in cancer invasiveness. Although research into miRNA’s function in cancer is still ongoing, results herein contribute to improved metastatic cancer management.

Prostatic epithelial cells and their high expressions of CKIP-1 affect the TGF-β1 expression levels which might reduce the scar formation in remodeling stage at prostatic urethral wounds after wound repair

Objective

There are less scar formations in some wounds after wound repair. Our earlier study had shown that the amount of collagen fibers in canine prostatic urethra wound were less than in bladder neck wound after 2-μm laser resection of the prostate (TmLRP) and partial bladder neck mucosa at 4 weeks. The purpose of this study was to observe the amount of scar tissue and characterize the probable causes of “less scar healing” in prostatic urethra wound.

Methods

A total of 12 healthy adult male crossbred canines underwent resection of prostate and partial bladder neck mucosa using 2-μm laser. The prostatic urethra and bladder neck wound specimens were harvested at 3, 4, 8 and 12 weeks after operation, respectively. The histopathologic characteristics were observed by hematoxylin and eosin(HE)staining, and the expression of transforming growth factor-β₁ (TGF-β₁) and casein kinase-2 interacting protein-1 (CKIP-1) were examined by immunohistochemistry in prostatic urethra and bladder neck wound, respectively. Overexpressed CKIP-1 human prostate epithelial cells (BPH-1 cells) were established and the expression of TGF-β₁ was detected by Western blotting. Furthermore, a non-contact co-culture system of BPH-1 cells and human fibroblast (HFF-1) cells was used to observe the effects of BPH-1 cell and their high CKIP-1 levels on the expression of TGF-β₁ in HFF-1 in vitro.

Results

The histology showed that there were a large number of prostatic epithelium and a small amount of scar tissue in prostatic urethra wound, while no epithelial cells and more scar tissue in bladder neck wound at 4, 8 and 12 weeks after repair. There were a higher expression level of TGF-β₁ in prostate epithelial cells and fibroblasts and a lower expression level of CKIP-1 in prostate epithelial cells at 3 weeks after surgery in prostatic urethral wound. Compared to week 3, the TGF-β₁ expression decreased both in prostate epithelial cells and fibroblasts at 4, 8 and 12 weeks in prostatic urethral wound (p < 0.05 or p < 0.01). The CKIP-1 expression increased in prostate epithelial cells at 4, 8 and 12 weeks compared to 3 weeks in prostatic urethra wound (p < 0.01). A higher TGF-β1 expression level of fibroblasts was observed in bladder neck wound at 3 weeks. And there was no significant change in the expression of TGF-β₁ of fibroblasts in 3, 4, 8 and 12 weeks after operation in bladder neck wound. Both the prostate urethra and bladder neck wound fibroblasts showed weak expression of CKIP-1 and there was no significant change in 3, 4, 8 and 12 weeks. The vitro experiments showed that the TGF-β₁ expression in BPH-1 cells with CKIP-1 overexpression decreased 25% compared with control group (p < 0.05). Furthermore, the expression of TGF-β₁ in HFF-1 cells of co-cultured group decreased by 20% compared with Control group (p < 0.05); the expression of TGF-β₁ in HFF-1 cells of overexpression co-culture group were reduced by 15% compared with co-cultured group (p < 0.01).

Conclusions

A large number of prostate epithelial cells in prostatic urethra wound may be one of the causes of less formation of scar tissue after repair. The prostate epithelial cells might reduce expression level of TGF-β₁ by raising CKIP-1 expression and inhibit expression of TGF-β₁ in peripheral fibroblasts at remodeling stage to reduce the excessive proliferation of fibrous cells and the excessive scar formation.

6-Formylindolo[3,2-b]carbazole (FICZ) Enhances The Expression of Tumor Suppressor miRNAs, miR-22, miR-515-5p, and miR-124-3p in MCF-7 Cells

Objective

microRNAs (miRNAs) play bifunctional roles in the initiation and progression of cancer, and recent evidence has confirmed that unusual expression of miRNAs is required for the progress of breast cancer. The regulatory role of aryl hydrocarbon receptor (AhR) and its endogenous ligand, 6-formylindolo[3,2-b]carbazole (FICZ) on the expression of tumor suppressor miRNAs, miR-22, miR-515-5p and miR-124-3p, as well as their association with the estrogen receptor alpha (ERα) were the aims of this study.

Materials and Methods

In this experimental study, the expression levels of miR-22, miR-515-5p, miR-124-3p and miR-382-5p in MCF-7 cells were determined using the quantificational real time polymerase chain reaction (qRT-PCR) assay.

Results

Our results revealed that miR-22, miR-515-5p, and miR-124-3p expressions were significantly increased in cells transfected with ERα siRNA. Our data also showed that miR-22, miR 515-5p, and miR-124-3p expression levels were significantly increased following FICZ treatment. Here, we found that AhR/ERα cross-talk plays a critical role in the expression of miR-22, miR-515-5p and miR-124-3p in MCF-7 cells.

Conclusion

Overall, our data demonstrated that FICZ, as an AhR agonist could induce the expression of tumor suppressor miRNAs, miR-22, miR-515-5p, and miR-124-3p; thus, FICZ might be regarded as a potential therapeutic agent for breast cancer treatment.

MicroRNA-124: An emerging therapeutic target in cancer

MicroRNAs (miRNAs) are noncoding single‐stranded RNAs, approximately 20‐24 nucleotides in length, known as powerful posttranscriptional regulators. miRNAs play important regulatory roles in cellular processes by changing messenger RNA expression and are widely involved in human diseases, including tumors. It has been reported in the literature that miRNAs have a precise role in cell proliferation, programmed cell death, differentiation, and expression of coding genes. MicroRNA‐124 (miR‐124) has reduced exparession in various human neoplasms and is believed to be related to the occurrence, development, and prognosis of malignant tumors. In our review, we focus on the specific molecular functions of miR‐124 and the downstream gene targets in major cancers, which provide preclinical evidence for the treatment of human cancer. Although some obstacles exist, miR‐124 is still attracting intensive research focus as a promising and effective anticancer weapon.

MicroRNA-124-3p suppresses cell migration and invasion by targeting ITGA3 signaling in bladder cancer

BACKGROUND

A growing body of studies have demonstrated the aberrant expression of microRNAs (miRNAs) contributes to human tumor metastasis. MicroRNA-124-3p (miR-124-3p), which is down-regulated in various cancers, has been found to be involved in several signaling pathways relevant to tumor cell migration and invasion. However, the roles of miR-124-3p in human bladder cancer remain unclear. This study aims to investigate the functional significance of miR-124-3p and to understand how it targets the integrin receptor, and thus affects the progression of human bladder cancer.

METHODS

Clinical specimens from 36 patients and three human bladder cancer cell lines were analyzed for miR-124-3p and integrin α3 (ITGA3) . To investigate the effects of miR-124-3p and ITGA3 on proliferation of bladder cancer cells, the MTT assay, colon-formation assay and flow cytometry were performed. In addition, wound healing assay and transwell assay were carried out to examine the migration and invasion of the bladder cancer cells transfected with miR-124-3p mimics or si-ITGA3. The luciferase reporter assay, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were applied to validate the miR-124-3p directly binding with ITGA3. Finally, western blot was used to examine the expression level of the proteins involved in FAK/PI3K/AKT and FAK/Src signal pathway as well as epithelial-mesenchymal transition (EMT) process.

RESULTS

The down-regulation of miR-124-3p and up-regulation of ITGA3 were observed in clinical specimens and bladder cancer cell lines. Overexpression of miR-124-3p or silencing ITGA3 inhibited tumor cell migration and invasion. Luciferase assay confirmed miR-124-3p directly targets ITGA3, and western blot suggested that miR-124-3p plays a crucial role in the EMT and metastasis of human bladder cancer through FAK/PI3K/AKT and FAK/Src signaling mechanism. Also, by targeting ITGA3, miR-124-3p can modulate the expression of N- and E-cadherin, and thus inhibit the EMT.

CONCLUSIONS

By targeting ITGA3 and downstream FAK/PI3K/AKT and FAK/Src signaling pathways, miR-124-3p suppresses cell migration and invasion in bladder cancer. Our study reasonably speculates that miR-124-3p can be potentially developed as a therapeutic target and prognostic biomarker for bladder cancer.

Interfering cellular lactate homeostasis overcomes Taxol resistance of breast cancer cells through the microRNA-124-mediated lactate transporter (MCT1) inhibition

Background

Breast cancer, the most common invasive cancer of women, is a malignant neoplasm and the second main cause of cancer death. Resistance to paclitaxel (Taxol), one of the frequently used chemotherapy agents for breast cancer, presents a major clinical challenge. Recent studies revealed that metabolic alterations of cancer cells play important roles in chemo-resistance.

Materials and methods

In this study, Human breast cancer cells, BT474, SKBR3 and MCF7 were used to study the causal relationship between the lactate exporter, MCT1 (SLC16A1)-modulated glucose metabolism and Taxol resistance of breast cancer cells. Taxol resistant breast cancer cells were established. The intracellular lactate and extracellular lactate levels as well glucose uptake and oxygen consumption were measured. MicroRNA-124 expressions were detected by qRT-PCR from both breast cancer patient samples and breast cancer cells. Target of miR-124 was predicted and verified by Western blot and luciferase assay. An xenograft mice model was established and evaluated for the in vivo tumor therapeutic effects of MCT1 inhibitor plus microRNA-124 treatments.

Results

Low toxic Taxol treatments promoted cellular glucose metabolism and intracellular lactate accumulation with upregulated lactate dehydrogenase-A (LDHA) and MCT1 expressions. By establishing Taxol resistant breast cancer cell line, we found Taxol resistant cells exhibit upregulated LDHA and MCT1 expressions. Furthermore, glucose consumption, lactate production and intracellular ATP were elevated in Taxol resistant MCF7 cells compared with their parental cells. The miR-124, a tumor suppressive miRNA, was significantly downregulated in Taxol resistant cells. Luciferase assay and q-RT-PCR showed MCT1 is a direct target of miR-124 in both breast cancer cell lines and patient specimens. Moreover, co-treatment of breast cancer cells with either MCT1 inhibitor or miR-124 plus Taxol led to synergistically cytotoxic effects. Importantly, based on in vitro and in vivo results, inhibition of MCT1 significantly sensitized Taxol resistant cells. Finally, rescue experiments showed restoration of MCT1 in miR-124 overexpressing cells promoted Taxol resistance.

Conclusions

This study reveals a possible role of miRNA-214-mediated Taxol resistance, contributing to identify novel therapeutic targets against chemoresistant breast cancers.

NEAT1/miR‑124/STAT3 feedback loop promotes breast cancer progression

The long non‑coding RNA nuclear enriched abundant transcript 1 (NEAT1) has important roles in the regulation of multiple cell functions, such as proliferation, apoptosis and migration. However, the mechanism by which NEAT1 regulates breast cancer progression is not well elucidated. In the present study, NEAT1 and microRNA‑124 (miR‑124) levels were detected by reverse transcription‑quantitative PCR in breast cancer tissues and cell lines. STAT3 protein levels were detected by western blot analysis. Cell proliferation and cell cycle distribution were determined using MTT and colony formation assays, and flow cytometry, respectively. The results demonstrated that NEAT1 and STAT3 expression levels were increased in breast cancer tissues compared with normal breast tissues, whereas miR‑124 expression was significantly decreased. Functional analyses revealed that NEAT1 promoted cell proliferation and cell cycle progression in breast cancer cells. Additionally, NEAT1 and STAT3 expression levels were negatively correlated with miR‑124 levels in breast cancer tissues. A direct interaction between miR‑124, and NEAT1 and STAT3, was predicted by bioinformatics analysis and confirmed using a luciferase activity assay. NEAT1 overexpression markedly increased STAT3 protein expression levels, and this effect was reversed by miR‑124 overexpression in breast cancer cells. Furthermore, miR‑124 overexpression partially attenuated the effects of NEAT1 on breast cancer cell proliferation and cell cycle progression. The inhibitory effects of miR‑124 overexpression on the proliferation rate and cell cycle progression were abolished by STAT3 overexpression. In turn, STAT3 silencing inhibited NEAT1 transcription in breast cancer cells. In summary, the present findings revealed that NEAT1 and STAT3 formed a feedback loop via sponging miR‑124 to promote breast cancer progression.

MicroRNA-410-3p upregulation suppresses proliferation, invasion and migration, and promotes apoptosis in rhabdomyosarcoma cells

Rhabdomyosarcoma (RMS) is one of the most common types of soft tissue sarcoma in children; however, the pathogenesis of RMS is unclear. MicroRNAs (miRs) are involved in the development and progression of RMS. The role of miR-410-3p in RMS cell invasion, migration, proliferation and apoptosis, and its possible mechanism were investigated in the current study. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were performed to detect the expression of miR-410-3p in RMS tissues and cells. In addition, the present study investigated the expression levels of molecules associated with the epithelial-mesenchymal transition (EMT), including E-cadherin, N-cadherin, Slug and Snail, and apoptotic factors, including Bcl-2-associated X protein (bax), cleaved-caspase 3, cleaved poly (ADP-ribose) polymerase (PARP), p53 and Bcl-2. Cell Counting Kit-8, terminal deoxynucleotidyl transferase dUTP nick end labeling and Transwell assays were conducted to determine the functional roles of miR-410-3p. Exogenous expression of miR-410-3p inhibited RMS cell invasion, migration and proliferation, induced apoptosis, suppressed the expression of Snail, Slug, N-cadherin and Bcl-2, and increased the expression of E-cadherin, bax, cleaved-caspase 3, cleaved PARP and p53. In summary, it was proposed that miR-410-3p overexpression suppressed invasion, migration and proliferation, downregulated the expression of EMT-associated molecules, and promoted apoptosis and the expression of apoptotic factors in RMS cells. Therefore, miR-410-3p may serve as a novel tumor suppressor gene in RMS, and could possess diagnostic and therapeutic potentials for the treatment of RMS.

Non-Coding RNAs as New Therapeutic Targets in the Context of Renal Fibrosis

Fibrosis, or tissue scarring, is defined as the excessive, persistent and destructive accumulation of extracellular matrix components in response to chronic tissue injury. Renal fibrosis represents the final stage of most chronic kidney diseases and contributes to the progressive and irreversible decline in kidney function. Limited therapeutic options are available and the molecular mechanisms governing the renal fibrosis process are complex and remain poorly understood. Recently, the role of non-coding RNAs, and in particular microRNAs (miRNAs), has been described in kidney fibrosis. Seminal studies have highlighted their potential importance as new therapeutic targets and innovative diagnostic and/or prognostic biomarkers. This review will summarize recent scientific advances and will discuss potential clinical applications as well as future research directions.

Exosomal transfer of miR-124 inhibits normal fibroblasts to cancer-associated fibroblasts transition by targeting sphingosine kinase 1 in ovarian cancer

OBJECTIVE

The interaction between tumor microenvironment and tumor cells plays a key role in tumor progression. However, the mechanisms by which this interaction promotes the transdifferentiation of normal fibroblasts (NFs) to cancer-associated fibroblasts (CAFs) are still unclear. The aim of this study was to investigate whether ovarian cancer (OvCa) cells-derived microRNAs were involved in the transition of resident fibroblasts to CAFs, and in promoting tumorigenesis.

METHODS

CAFs and NFs were isolated from the same ovarian site in OvCa and noncancerous prophylactic oophorectomy specimens. The effect of exosomes on the motility of CAFs or NFs was analyzed by wound healing and Transwell assays. The expression of CAFs marker α-smooth muscle actin (α-SMA) and fibroblast activated protein (FAP) were determined by quantitative real-time PCR and Western blotting. A luciferase reporter assay was used to test the interaction between miR-124 and sphingosine kinase 1 (SPHK1).

RESULTS

NFs with downregulated miR-124 displayed the characteristics of CAFs, including overexpression of α-SMA and FAP and increased migratory and invasive ability. Overexpression of miR-124 in CAFs reversed some traits of NFs. Human ovarian surface epithelial cells-secreted miR-124 could be transferred via exosomes to CAFs and resulted in decreased α-SMA and FAP expression and attenuated cell motility. Moreover, our finding showed that the expression of SPHK1, a potential target of miR-124, was significantly elevated in CAFs.

CONCLUSIONS

The present study provides important and novel perspective into OvCa CAF differentiation and extracellular matrix remodeling, which trigger the tumor progression.