MiR-124 inhibits the migration and invasion of human hepatocellular carcinoma cells by suppressing integrin αV expression

MicroRNA as Key Players in Hepatocellular Carcinoma: Insights into Their Role in Metastasis

Liver cancer or hepatocellular carcinoma (HCC) remains the most common cancer in global epidemiology. Both the frequency and fatality of this malignancy have shown an upward trend over recent decades. Liver cancer is a significant concern due to its propensity for both intrahepatic and extrahepatic metastasis. Liver cancer metastasis is a multifaceted process characterized by cell detachment from the bulk tumor, modulation of cellular motility and invasiveness, enhanced proliferation, avoidance of the immune system, and spread either via lymphatic or blood vessels. MicroRNAs (miRNAs) are small non-coding ribonucleic acids (RNAs) playing a crucial function in the intricate mechanisms of tumor metastasis. A number of miRNAs can either increase or reduce metastasis via several mechanisms, such as control of motility, proliferation, attack by the immune system, cancer stem cell properties, altering the microenvironment, and the epithelial-mesenchymal transition (EMT). Besides, two other types of non-coding RNAs, such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) can competitively bind to endogenous miRNAs. This competition results in the impaired ability of the miRNAs to inhibit the expression of the specific messenger RNAs (mRNAs) that are targeted. Increasing evidence has shown that the regulatory axis comprising circRNA/lncRNA-miRNA-mRNA is correlated with the regulation of HCC metastasis. This review seeks to present a thorough summary of recent research on miRNAs in HCC, and their roles in the cellular processes of EMT, invasion and migration, as well as the metastasis of malignant cells. Finally, we discuss the function of the lncRNA/circRNA-miRNA-mRNA network as a crucial modulator of carcinogenesis and the regulation of signaling pathways or genes that are relevant to the metastasis of HCC. These findings have the potential to offer valuable insight into the discovery of novel therapeutic approaches for management of liver cancer metastasis.

The Role of MicroRNA-124-3p in Breast Cancer Stem Cell Inhibition by Benzyl Isothiocyanate

PURPOSE

We have shown previously that benzyl isothiocyanate (BITC) derived from cruciferous vegetables inhibits self-renewal of breast cancer stem-like cells (bCSC). The current study provides insights into the mechanism of bCSC inhibition by BITC.

METHODS

Quantitative real time-polymerase chain reaction and western blot analysis were performed to detect microRNAs (miRNAs) and Forkhead box Q1 (FoxQ1) protein expression, respectively. The bCSC were characterized by aldehyde dehydrogenase 1 activity and flow cytometric analysis of CD49f high/CD133high fraction.

RESULTS

BITC treatment resulted in induction of miR-124-3p expression in MDA-MB-231 and MCF-7 cells. miR-124-3p did not affect BITC-mediated inhibition of cell migration or cell proliferation but it significantly regulated bCSC in response to BITC. We also found that miR-124-3p directly targets the 3'untranslated regions (UTR) of FoxQ1 and negatively regulates its expression. The BITC-mediated inhibition of bCSC was partially attenuated by miR-124-3p inhibitor.

CONCLUSIONS

These findings indicate that miR-124-3p plays an important role in BITC-mediated inhibition of bCSC.

MicroRNAs in Hepatocellular Carcinoma Pathogenesis: Insights into Mechanisms and Therapeutic Opportunities

Hepatocellular carcinoma (HCC) presents a significant global health burden, with alarming statistics revealing its rising incidence and high mortality rates. Despite advances in medical care, HCC treatment remains challenging due to late-stage diagnosis, limited effective therapeutic options, tumor heterogeneity, and drug resistance. MicroRNAs (miRNAs) have attracted substantial attention as key regulators of HCC pathogenesis. These small non-coding RNA molecules play pivotal roles in modulating gene expression, implicated in various cellular processes relevant to cancer development. Understanding the intricate network of miRNA-mediated molecular pathways in HCC is essential for unraveling the complex mechanisms underlying hepatocarcinogenesis and developing novel therapeutic approaches. This manuscript aims to provide a comprehensive review of recent experimental and clinical discoveries regarding the complex role of miRNAs in influencing the key hallmarks of HCC, as well as their promising clinical utility as potential therapeutic targets.

MicroRNA (miR)-124: A Promising Therapeutic Gateway for Oncology

MicroRNA (miR) are a class of small non-coding RNA that are involved in post-transcriptional gene regulation. Altered expression of miR has been associated with several pathological conditions. MicroRNA-124 (miR-124) is an abundantly expressed miR in the brain as well as the thymus, lymph nodes, bone marrow, and peripheral blood mono-nuclear cells. It plays a key role in the regulation of the host immune system. Emerging studies show that dysregulated expression of miR-124 is a hallmark in several cancer types and it has been attributed to the progression of these malignancies. In this review, we present a comprehensive summary of the role of miR-124 as a promising therapeutic gateway in oncology.

Integrins in human hepatocellular carcinoma tumorigenesis and therapy

ABSTRACT

Integrins are a family of transmembrane receptors that connect the extracellular matrix and actin skeleton, which mediate cell adhesion, migration, signal transduction, and gene transcription. As a bi-directional signaling molecule, integrins can modulate many aspects of tumorigenesis, including tumor growth, invasion, angiogenesis, metastasis, and therapeutic resistance. Therefore, integrins have a great potential as antitumor therapeutic targets. In this review, we summarize the recent reports of integrins in human hepatocellular carcinoma (HCC), focusing on the abnormal expression, activation, and signaling of integrins in cancer cells as well as their roles in other cells in the tumor microenvironment. We also discuss the regulation and functions of integrins in hepatitis B virus-related HCC. Finally, we update the clinical and preclinical studies of integrin-related drugs in the treatment of HCC.

MicroRNA-29a and MicroRNA-124 as novel biomarkers for hepatocellular carcinoma

BACKGROUND

Numerous microRNAs (miRNAs) have been observed to be abnormally expressed in cancer. Therefore, miRNA signatures could be potential noninvasive diagnostic and prognostic biomarkers for hepatocellular carcinoma (HCC).

AIMS

To correlate miRNA-29a and miRNA-124 expression levels with the clinical features and survival rates of HCC patients.

METHODS

Serum miRNA expression in 150 samples (50 patients with HCC, 50 patients with liver cirrhosis, and 50 healthy controls) were quantified using real-time qRT-PCR.

RESULTS

The expression levels of serum miRNA-29a were higher and the levels of miRNA-124 were lower in patients with HCC than in patients with liver cirrhosis and controls. ROC curve analysis showed promising accuracy for both miRNAs in distinguishing patients with HCC from those with liver cirrhosis. Levels of miRNA-29a were related to tumor number, size, stage, and outcome, whereas levels of miRNA-124 were related to vascular invasion. The overall survival rate of patients with low miRNA-29a expression was significantly higher than that of patients with high expression. Additionally, the multivariate analysis identified miRNA-29a as an independent prognostic variable.

CONCLUSIONS

The investigated miRNAs showed acceptable accuracy in the diagnosis of HCC; therefore, both could be utilized as diagnostic biomarkers. Additionally, miRNA-29a could be used as a prognostic biomarker.

Aberrant methylation of miR-124 upregulates DNMT3B in colorectal cancer to accelerate invasion and migration

The dysregulation of microRNA expression is significantly associated with the initiation and development of CRC. miR-124 is markedly downregulated in colorectal cancer. In the present study, the effects of methylation, over expression and downregulation of miR-124 and its target gene DNMT3B on the proliferation, migration and invasion of colorectal cell line were investigated. The promoter methylation status of miR-124 in the CRC was investigated by methylation specific PCR (MSP). The potential role of miR-124 expression in CRC cells was investigated using the demethylation reagent 5-Aza-CdR and transfection of miR-124 mimic/antimir. MSP revealed that miR-124 promoter region was hypermethylated, result in its significant downregulation in tumour tissues. We showed miR-124 expression was upregulated following 5-AZA-CdR treatment. Transfected Hct-116 cell line with miR-124 leads to decreased DNMT3B expression, cell proliferation, migration and invasion of HCT-116. In conclusion, our data indicate that miR-124 suppress colorectal cancer proliferation, migration and invasion through downregulating DNMT3B level.

Immune-related biomarkers shared by inflammatory bowel disease and liver cancer

It has been indicated that there is an association between inflammatory bowel disease (IBD) and hepatocellular carcinoma (HCC). However, the molecular mechanism underlying the risk of developing HCC among patients with IBD is not well understood. The current study aimed to identify shared genes and potential pathways and regulators between IBD and HCC using a system biology approach. By performing the different gene expression analyses, we identified 871 common differentially expressed genes (DEGs) between IBD and HCC. Of these, 112 genes overlapped with immune genes were subjected to subsequent bioinformatics analyses. The results revealed four hub genes (CXCL2, MMP9, SPP1 and SRC) and several other key regulators including six transcription factors (FOXC1, FOXL1, GATA2, YY1, ZNF354C and TP53) and five microRNAs (miR-124-3p, miR-34a-5p, miR-1-3p, miR-7-5p and miR-99b-5p) for these disease networks. Protein-drug interaction analysis discovered the interaction of the hub genes with 46 SRC-related and 11 MMP9- related drugs that may have a therapeutic effect on IBD and HCC. In conclusion, this study sheds light on the potential connecting mechanisms of HCC and IBD.

Gene methylation of CADM1 and MAL identified as a biomarker of high grade anal intraepithelial neoplasia

Human papillomavirus (HPV) is detected in up to 96% of anal squamous cell cancers, where screening programs needed. However, the best methodology is still undetermined. Host DNA methylation markers CADM1, MAL and miR124 have been identified in cervical disease, but not anal disease. Anal swabs varying by disease grade were assessed for DNA methylation of CADM1, MAL and miR124-2. Each marker was compared across disease grades, stratified by HPV and HIV status. Receiver operating characteristic curves identified the predictive value of significant gene candidates. CADM1 methylation was significantly higher in high-grade squamous intraepithelial lesions (HSIL) compared with low-grade (LSIL) (p = 0.005) or normal (p < 0.001) samples with 67.2% correctly identified as HSIL. MAL methylation was significantly (p = 0.002) increased in HSIL compared with LSIL in HIV positive participants with 79.8% correctly indicated as HSIL. Gene miR124-2, showed no difference between disease grades. Biomarkers with established diagnostic value in cervical disease have limited utility in the prediction of anal disease, with CADM1 identified as a marker with screening potential in a gay and bisexual men (GBM) population and MAL in HIV positive GBM population. New markers specific to the anal mucosa are required to improve triage of high-risk individuals.

Changes in Methylation across Structural and MicroRNA Genes Relevant for Progression and Metastasis in Colorectal Cancer

MiRs are important players in cancer and primarily genetic/transcriptional means of regulating their gene expression are known. However, epigenetic changes modify gene expression significantly. Here, we evaluated genome-wide methylation changes focusing on miR genes from primary CRC and corresponding normal tissues. Differentially methylated CpGs spanning CpG islands, open seas, and north and south shore regions were evaluated, with the largest number of changes observed within open seas and islands. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed several of these miRs to act in important cancer-related pathways, including phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt) and mitogen-activated protein kinase (MAPK) pathways. We found 18 miR genes to be significantly differentially methylated, with MIR124-2, MIR124-3, MIR129-2, MIR137, MIR34B, MIR34C, MIR548G, MIR762, and MIR9-3 hypermethylated and MIR1204, MIR17, MIR17HG, MIR18A, MIR19A, MIR19B1, MIR20A, MIR548F5, and MIR548I4 hypomethylated in CRC tumor compared with normal tissue, most of these miRs having been shown to regulate steps of metastasis. Generally, methylation changes were distributed evenly across all chromosomes with predominance for chromosomes 1/2 and protein-coding genes. Interestingly, chromosomes abundantly affected by methylation changes globally were rarely affected by methylation changes within miR genes. Our findings support additional mechanisms of methylation changes affecting (miR) genes that orchestrate CRC progression and metastasis.

Extracellular vesicles from tonsil‑derived mesenchymal stromal cells show anti‑tumor effect via miR‑199a‑3p

Mesenchymal stem cells (MSCs) are mesoderm‑originated adult SCs that possess multidirectional differentiation potential. MSCs migrate to injured tissue and secrete a range of paracrine factors that induce regeneration in damaged tissue and exert immune modulation. Because tumor progression is dependent on cross‑talk between the tumor and its microenvironment, MSCs also produce extracellular vesicles (EVs) that mediate information transfer in the tumor microenvironment. However, the effect of MSC‑derived EVs on tumor development and progression is still controversial. To date, tonsil‑derived MSCs (T‑MSCs) have been shown to possess all the defined characteristics of MSCs and show distinctive features of differential potential and immune modulation. To observe the effect of soluble mediators from T‑MSCs on tumor growth, human liver cancer cell line (HepG2) cells were injected into nude mice and HepG2 cell scratch migration assay was performed using conditioned medium (CM) of T‑MSCs. T‑MSC CM inhibited tumor growth and progression and it was hypothesized that EVs from T‑MSCs could inhibit tumor progression. microRNA (miRNA or miR) sequencing using five different origins of T‑MSC‑derived EVs was performed and highly expressed miRNAs, such as miR‑199a‑3p, miR‑214‑3p, miR‑199a‑5p and miR‑199b‑5p, were selected. T‑MSCs inhibited tumor growth and HepG2 cell migration, potentially via miR‑199a‑3p targeting CD151, integrin α3 and 6 in HepG2 cells.

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.

miR-124-3p Suppresses the Invasiveness and Metastasis of Hepatocarcinoma Cells via Targeting CRKL

Abnormal expressions of microRNAs are involved in growth and progression of human cancers including hepatocellular carcinoma (HCC). An adaptor protein CRKL plays a pivotal role in HCC growth, whereas miR-124-3p downregulation is associated with clinical stage and the poor survival of patients. However, the relationship between miR-124-3p and CRKL and the molecular mechanisms through which they regulate HCC metastasis remains unclear. In the current work, we explored miR-124-3p and its correlation with CRKL expression in HCC patient tissues. We found that miR-124-3p deficiency is inversely co-related with CRKL overexpression in tumorous tissues of HCC patients, which was also consistent in HCCLM3 and Huh7 HCC cell lines. Target validation data shows that miR-124-3p directly targets CRKL. The overexpression of miR-124-3p reverses the CRKL expression at both mRNA and protein levels and inhibits the cell development, migration, and invasion. Mechanistic investigations showed that CRKL downregulation suppresses the ERK pathway and EMT process, and concomitant decrease in invasion and metastasis of HCC cells. The expressions of key molecules in the ERK pathway such as RAF, MEK, ERK1/2, and pERK1/2 and key promoters of EMT such as N-cadherin and vimentin were downregulated, whereas E-cadherin, a key suppression indicator of EMT, was upregulated. MiR-124-3p-mediated CRKL suppression led to BAX/BCL-2 increase and C-JUN downregulation, which inhibited the cell proliferation and promoted the apoptosis in HCC cells. Collectively, our data illustrates that miR-124-3p acts as an important tumor-suppressive miRNA to suppress HCC carcinogenesis through targeting CRKL. The miR-124-3p-CRKL axial regulated pathway may offer valuable indications for cancer research, diagnosis, and treatment.

Rab27A promotes cellular apoptosis and ROS production by regulating the miRNA-124-3p/STAT3/RelA signalling pathway in ulcerative colitis

Ulcerative colitis (UC) is a multifactorial inflammatory disease, and increasing evidence has demonstrated that the mechanism of UC pathogenesis is associated with excessive cellular apoptosis and reactive oxygen species (ROS) production. However, their function and molecular mechanisms related to UC remain unknown. In this study, Rab27A mRNA and protein were proven to be overexpressed in intestinal epithelial cells of UC patients and DSS‐induced colitis mice, compared with control (P < 0.05). And Rab27A silencing inhibits inflammatory process in DSS‐induced colitis mice (P < 0.05). Then, it was shown that knockdown of Rab27A suppressed apoptosis and ROS production through modulation of miR‐124‐3p, whereas overexpression of Rab27A promoted apoptosis and ROS production in LPS‑induced colonic cells. In addition, enhanced expression of miR‐124‐3p attenuated apoptosis and ROS production by targeting regulation of STAT3 in LPS‑induced colonic cells. Mechanistically, we found Rab27A reduced the expression and activity of miR‐124‐3p to activate STAT3/RelA signalling pathway and promote apoptosis and ROS production in LPS‑induced colonic cells, whereas overexpression of miR‐124‐3p abrogated these effects of Rab27A. More importantly, animal experiments illustrated that ectopic expression of Rab27A promoted the inflammatory process, whereas overexpression of miR‐124‐3p might interfere with the inflammatory effect in DSS‐induced colitis mice. In summary, Rab27A might modulate the miR‐124‐3p/STAT3/RelA axis to promote apoptosis and ROS production in inflammatory colonic cells, suggesting that Rab27A as a novel therapeutic target for the prevention and treatment of UC patients.

MiR-124a Regulates Extracellular Vesicle Release by Targeting GTPase Rabs in Lung Cancer

Lung cancer is the leading cause of cancer mortality worldwide. Increased understanding of the molecular mechanisms of the disease has led to the development of novel therapies and improving outcomes. Recently, extracellular vesicles (EVs) have emerged as vehicles for the transfer of genetic information between tumors and their microenvironment and have been implicated in lung cancer initiation, progression, and response to therapy. However, the mechanisms that drive the biogenesis and selective packaging of EVs remain poorly understood. Rab family guanosine triphosphates (GTPases) and their regulators are important membrane trafficking organizers. In this study, we investigated the role of select Rab GTPases on the regulation of EV release. We found that microRNAs target Rab GTPases to regulate EV release from lung cancer cell lines. In particular, Rab32 is a target of miR-124a, and siRNA and miRNA mediated inhibition of Rab32 leads to impaired EV secretion. The downstream implications for microRNA-based regulation of EV release are currently under investigation.

ZKSCAN3 drives tumor metastasis via integrin β4/FAK/AKT mediated epithelial-mesenchymal transition in hepatocellular carcinoma

BACKGROUND

ZKSCAN3, a zinc-finger transcription factor containing KRAB and SCAN domains, has been reported to be regulated in several human cancers. However, its expression and function in hepatocellular carcinoma (HCC) remains unknown.

METHODS

Expression of ZKSCAN3 in HCC was analyzed by western blotting, immunohistochemistry, and real time PCR. Its correlation with the clinicopathological characteristics and prognosis of HCC patients was analyzed. The effects of ZKSCAN3 on the migration and invasion were determined by Transwell assays. The potential downstream targets of ZKSCAN3 and related molecular mechanisms were clarified by Western blot and dual luciferase reporter assay.

RESULTS

In this study, we demonstrated for the first time that ZKSCAN3 mRNA and protein was up-regulated in HCC tissues and cell lines. High ZKSCAN3 expression was significantly associated with poor prognostic features, including advanced TNM stage and vascular invasion. For 5-year survival, ZKSCAN3 served as a potential prognostic marker of HCC patients. Functionally, ZKSCAN3 promoted migration, invasion and EMT progress via directly binding to integrin β4 (ITGB4) promoter and enhanced its expression. Further investigation proved that ITGB4 triggers the focal adhesion kinase (FAK) to activate the AKT signaling pathway. Inactivation of FAK and AKT by their specific inhibitors respectively reversed the effects of ZKSCAN3 on HCC cells. In addition, we demonstrated that ZKSCAN3 expression was regulated by miR-124. In HCC tissues. MiR-124 has an inverse correlation with ZKSCAN3 expression.

CONCLUSION

We demonstrate for the first time that ZKSCAN3 is overexpressed in HCC tissues and promotes migration, invasion and EMT process through ITGB4-dependent FAK/AKT activation, which was regulated by miR-124, suggesting the potential therapeutic value for HCC.

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.

PRAS40 hyperexpression promotes hepatocarcinogenesis

Background

Hepatocellular carcinoma (HCC) is one of the most common cancers, whereas the molecular mechanism remains largely unknown. PRAS40 (encoded by AKT1S1) phosphorylation was increased in human melanoma, prostate cancer and lung cancer specimens, which was considered as the results of Akt activation. However the mechanism in detail and its role in HCC stay elusive.

Methods

PRAS40 expression and phosphorylation were analyzed in HCC specimens, and the survival rates of patients were investigated. Functional analyses of PRAS40 in HCC were performed in vivo and in vitro. The miR-124-3p binding sites in PRAS40 were investigated using luciferase assay. MiR-124-3p expression in HCC specimens was examined by In Situ hybridization, and the correlation to PRAS40 level was evaluated.

Findings

The phosphorylation, protein and mRNA levels of PRAS40 were increased significantly in HCC specimens from our cohorts and TCGA database, which was positively correlated to the poor prognosis of HCC patients. Compared to Akt1s1^+/+ mice, hepatocarcinogenesis was suppressed in Akt1s1^−/− mice, and the activation of Akt was impaired. PRAS40 depletion resulted in the inhibition of HCC cellular proliferation. Tumor suppressor miR-124-3p was found to downregulate PRAS40 expression by targeting its 3′UTR. MiR-124-3p levels were inversely correlated to PRAS40 protein and phosphorylation levels in HCC specimens. The proliferation inhibition by miR-124-3p mimics was partially reversed by exogenous PRAS40 introduction in HCC cells.

Interpretation

PRAS40 hyperexpression induced by loss of miR-124-3p contributes to PRAS40 hyperphosphorylation and hepatocarcinogenesis. These results could be expected to offer novel clues for understanding hepatocarcinogenesis and developing approaches.

TAZ target gene ITGAV regulates invasion and feeds back positively on YAP and TAZ in liver cancer cells

The Hippo pathway effectors yes-associated protein (YAP) and WW domain containing transcription regulator 1 (TAZ/WWTR1) support tumor initiation and progression in various cancer entities including hepatocellular carcinoma (HCC). However, to which extent YAP and TAZ contribute to liver tumorigenesis via common and exclusive molecular mechanisms is poorly understood. RNAinterference (RNAi) experiments illustrate that YAP and TAZ individually support HCC cell viability and migration, while for invasion additive effects were observed. Comprehensive expression profiling revealed partly overlapping YAP/TAZ target genes as well as exclusively regulated genes. Integrin-αV (ITGAV) is a novel TAZ-specific target gene, whose overexpression in human HCC patients correlates with poor clinical outcome, TAZ expression in HCCs, and the abundance of YAP/TAZ target genes. Functionally, ITGAV contributes to actin stress fiber assembly, tumor cell migration and invasion. Perturbation of ITGAV diminishes actin fiber formation and nuclear YAP/TAZ protein levels. We describe a novel Hippo downstream mechanism in HCC cells, which is regulated by TAZ and ITGAV and that feedbacks on YAP/TAZ activity. This mechanism may represent a therapeutic target structure since it contributes to signal amplification of oncogenic YAP/TAZ in hepatocarcinogenesis.

SO2 derivatives and As co-exposure promote liver cancer metastasis through integrin αvβ3 activation

Arsenic (As) and sulfur dioxide (SO₂) are two environmental pollutants that have been shown to promote the development of human cancer. In recent years, due to increased pollution, humans are often exposed to SO₂, in addition to As. Despite the development and implementation of standards for environment and air quality, cases of disease caused by As or SO₂ continue to rise alarmingly. It is currently unknown whether simultaneous exposure to As and SO₂ results in increased cancer promoting activity. In this study, concentrations of As and SO₂ below the limits established by the world health organization (WHO) in force environmental standards (concentrations of As should be lower than 1×10^-2 mg/L and SO₂ should be lower than 50 μg/m³), were employed to investigate possible, long-term, synergistic effects of As and SO₂, by using cell-based assays. We found that co-exposure to these pollutants significantly promotes HepG2 cancer cell migration, while As or SO₂ alone have no remarkable effects. Integrins αvβ3 play a key role in this process, as cilengitide, an integrin αvβ3 inhibitor, substantially prevented As and SO₂-induced cell migration. MMPs, IL-8, and TGF-β were also involved in the induced cell migration. In summary, combined exposure to As and SO₂ promotes integrin-dependent cell migration and may be of relevance for the activation of mechanisms underlying liver cancer progression.

Automatic discovery of 100-miRNA signature for cancer classification using ensemble feature selection

Background

MicroRNAs (miRNAs) are noncoding RNA molecules heavily involved in human tumors, in which few of them circulating the human body. Finding a tumor-associated signature of miRNA, that is, the minimum miRNA entities to be measured for discriminating both different types of cancer and normal tissues, is of utmost importance. Feature selection techniques applied in machine learning can help however they often provide naive or biased results.

Results

An ensemble feature selection strategy for miRNA signatures is proposed. miRNAs are chosen based on consensus on feature relevance from high-accuracy classifiers of different typologies. This methodology aims to identify signatures that are considerably more robust and reliable when used in clinically relevant prediction tasks. Using the proposed method, a 100-miRNA signature is identified in a dataset of 8023 samples, extracted from TCGA. When running eight-state-of-the-art classifiers along with the 100-miRNA signature against the original 1046 features, it could be detected that global accuracy differs only by 1.4%. Importantly, this 100-miRNA signature is sufficient to distinguish between tumor and normal tissues. The approach is then compared against other feature selection methods, such as UFS, RFE, EN, LASSO, Genetic Algorithms, and EFS-CLA. The proposed approach provides better accuracy when tested on a 10-fold cross-validation with different classifiers and it is applied to several GEO datasets across different platforms with some classifiers showing more than 90% classification accuracy, which proves its cross-platform applicability.

Conclusions

The 100-miRNA signature is sufficiently stable to provide almost the same classification accuracy as the complete TCGA dataset, and it is further validated on several GEO datasets, across different types of cancer and platforms. Furthermore, a bibliographic analysis confirms that 77 out of the 100 miRNAs in the signature appear in lists of circulating miRNAs used in cancer studies, in stem-loop or mature-sequence form. The remaining 23 miRNAs offer potentially promising avenues for future research.

Electronic supplementary material

The online version of this article (10.1186/s12859-019-3050-8) contains supplementary material, which is available to authorized users.

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.

The Identification and Analysis of mRNA-lncRNA-miRNA Cliques From the Integrative Network of Ovarian Cancer

Ovarian cancer is one of the leading causes of cancer mortality in women. Since little clinical symptoms were shown in the early period of ovarian cancer, most patients were found in phases III-IV or with abdominal metastasis when diagnosed. The lack of effective early diagnosis biomarkers makes ovarian cancer difficult to screen. However, in essence, the fundamental problem is we know very little about the regulatory mechanisms during tumorigenesis of ovarian cancer. There are emerging regulatory factors, such as long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), which have played important roles in cancers. Therefore, we analyzed the RNA-seq profiles of 407 ovarian cancer patients. An integrative network of 20,424 coding RNAs (mRNAs), 10,412 lncRNAs, and 742 miRNAs were construed with variance inflation factor (VIF) regression method. The mRNA-lncRNA-miRNA cliques were identified from the network and analyzed. Such promising cliques showed significant correlations with survival and stage of ovarian cancer and characterized the complex sponge regulatory mechanism, suggesting their contributions to tumorigenicity. Our results provided novel insights of the regulatory mechanisms among mRNAs, lncRNAs, and miRNAs and highlighted several promising regulators for ovarian cancer detection and treatment.

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.

Upregulation of MiR-212 Inhibits Migration and Tumorigenicity and Inactivates Wnt/β-Catenin Signaling in Human Hepatocellular Carcinoma

BACKGROUND

MicroRNAs are involved in hepatocellular carcinoma metastasis, a principal cause of hepatocellular carcinoma-related death in patients worldwide. MiR-212 is a microRNA that has been identified in several types of cancers and is postulated to influence cell signaling and subsequent malignant pathogenesis. Despite emerging reports suggesting that miR-212 plays a significant role in the onset, progression, and migration of these types of malignant tumors, its involvement in the development of hepatocellular carcinoma has not been fully elucidated.

MATERIALS AND METHODS

Quantitative reverse transcription polymerase chain reaction, wound healing, transwell migration and invasion assays, Western blotting, and xenograft tumor growth models were performed to test the expression levels and functions of miR-212 in hepatocellular carcinoma. Luciferase reporter assay, quantitative reverse transcription polymerase chain reaction, Western blotting, and immunohistochemistry were used to identify and verify the target of miR-212.

RESULTS

In this study, we identify significant repression of miR-212 in hepatocellular carcinoma and demonstrate that overexpression of miR-212 inhibits the migration of hepatocellular carcinoma cells in vitro and in vivo. Furthermore, we identify forkhead box M1, whose expression is inversely related to that of miR-212, as a direct target of miR-212. Additionally, reexpression of forkhead box M1 rescues the miR-212-mediated inhibition of cell migration. We observed that inhibition of miR-212 activates forkhead box M1 but inhibits the Wnt/β-catenin pathway by suppressing Wnt, LEF-1, c-Myc, and nuclear β-catenin. Finally, in vivo studies confirmed the inhibitory effect of miR-212 on hepatocellular carcinoma growth.

CONCLUSION

Our present findings indicate that miR-212 is a potential prognostic biomarker of hepatocellular carcinoma and that the miR-212/forkhead box M1 regulatory axis may represent a new therapeutic objective for hepatocellular carcinoma treatment.

Involvement of anti-tumor miR-124-3p and its targets in the pathogenesis of pancreatic ductal adenocarcinoma: direct regulation of ITGA3 and ITGB1 by miR-124-3p

MicroRNAs (miRNAs) are unique in that a single miRNA molecule regulates a vast number of RNA transcripts. Thus, aberrantly expressed miRNAs disrupt tightly controlled RNA networks in cancer cells. Our functional screening showed that expression of miR-124-3p was downregulated in pancreatic ductal adenocarcinoma (PDAC) tissues. Here, we aimed to investigate the anti-tumor roles of miR-124-3p in PDAC cells and to identify miR-124-3p-mediated oncogenic signaling in this disease. Ectopic expression of miR-124-3p inhibited cancer cell migration and invasion in PDAC cells. Moreover, restoration of miR-124-3p suppressed oncogenic signaling, as demonstrated by reduced phosphorylation of focal adhesion kinase, AKT, and extracellular signal-regulated kinase, in PDAC cells. Our in silico database analyses and luciferase reporter assays showed that two cell-surface matrix receptors, integrin α3 (ITGA3) and integrin β1 (ITGB1), were directly regulated by miR-124-3p in PDAC cells. Overexpression of ITGA3 and ITGB1 was confirmed in PDAC clinical specimens. Interestingly, a large number of cohort analyses from TCGA database showed that high expressions of ITGA3 and ITGB1 were significantly associated with poor prognosis of patients with PDAC. Knockdown of ITGA3 and ITGB1 by siRNAs markedly suppressed the migration and invasion abilities of PDAC cells. Moreover, downstream oncogenic signaling was inhibited by ectopic expression of miR-124-3p or knockdown of the two integrins. The discovery of anti-tumor miRNAs and miRNA-mediated oncogenic signaling may provide novel therapeutic targets for the treatment of PDAC.

Blockade of ITGA2 Induces Apoptosis and Inhibits Cell Migration in Gastric Cancer

Background

Gastric cancer is currently the fourth leading cause of cancer-related death worldwide. Gastric cancer is often diagnosed at advanced stages and the outcome of the treatment is often poor. Therefore, identifying new therapeutic targets for this cancer is urgently needed. Integrin alpha 2 (ITGA2) subunit and the beta 1 subunit form a heterodimer for a transmembrane receptor for extracellular matrix, is an important molecule involved in tumor cell proliferation, survival and migration. Integrin α2β1 is over-expressed on a variety of cancer cells, but is low or absent in most normal organs and resting endothelial cells.

Results

In this report, we assessed the ITGA2 as the potential therapeutic target with the bioinformatics tools from the TCGA dataset in which composed of 375 gastric cancer tissues and 32 gastric normal tissues. According to the information from the Cancer Cell Line Encyclopedia (CCLE) database, the AGS cell line with ITGA2 high expression and the SUN-1 cell line with low expression were chosen for the further investigation. Interestingly, the anti-ITGA2 antibody (at 3 μg/ml) inhibited approximately 50% survival of the AGS cells (over-expressed ITGA2), but had no effect in SNU-1 cells (ITGA2 negative). The extents of antibody-mediated cancer inhibition positively correlated with the expression levels of the ITGA2. We further showed that the anti-ITGA2 antibody induced apoptosis by up-regulating the RhoA-p38 MAPK signaling to promote the expressions of Bim, Apaf-1 and Caspase-9, whereas the expressions of Ras and Bax/Bcl-2 were not affected. Moreover, blocking ITGA2 by the specific antibody at lower doses also inhibited cell migration of gastric cancer cells. Blockade of ITGA2 by a specific antibody down-regulated the expression of N-WASP, PAK and LIMK to impede actin organization and cell migration of gastric cancer cells.

Conclusions

Here, we showed that the mRNA expression levels of ITGA2 comparing to normal tissues significantly increased. In addition, the results revealed that targeting integrin alpha 2 subunit by antibodies did not only inhibit cell migration, but also induce apoptosis effect on gastric cancer cells. Interestingly, higher expression level of ITGA2 led to significant effects on apoptosis progression during anti-ITGA2 antibody treatment, which indicated that ITGA2 expression levels directly correlate with their functionality. Our findings suggest that ITGA2 is a potential therapeutic target for gastric cancer.

MicroRNA-124 acts as a tumor-suppressive miRNA by inhibiting the expression of Snail2 in osteosarcoma

The aim of the present study was to investigate the clinical significance of hsa-microRNA-124-3p (miR-124) in osteosarcoma (OS), and examine its role in cell growth and invasion. Using a microRNA chip array, the expression of miR-124 was detected in samples of surgically resected OS and matched against the levels of expression in tumor-adjacent normal tissues. The levels of miR-124 were upregulated in the OS cells through the transfection of miR-124 mimics. Cell proliferation and Transwell assays were performed to determine cell proliferation and invasion; Reverse transcription-quantitative polymerase chain reaction, western blot and luciferase assays were then used to detect the expression of the target gene snail family zinc finger 2 (Snail2). The expression of miR-124 was significantly lower in the OS tissues, compared with that in the tumor-adjacent normal tissues; and the expression of miR-124 in the tumor tissues was significantly associated with tumor size. miR-124 directly repressed the expression of Snail2, and resulted in a significant inhibition of cell proliferation and invasion. In a mouse model, the overexpression of miR-124 significantly inhibited U2OS cell proliferation and invasion. Taken together, miR-124 was associated with the adverse clinical and pathological features observed in OS. It acted as a tumor suppressor to regulate the proliferation and invasion of OS cells by targeting Snail2, suggesting that miR-124 may be key in the progression of OS.

Retracted Article: PVT1 knockdown alleviates vancomycin-induced acute kidney injury by targeting miR-124 via inactivation of NF-κB signaling

Acute kidney injury (AKI) is a serious threat for human health and life. High dose of vancomycin (VAN) can give rise to AKI. The roles and molecular basis of long noncoding RNA plasmacytoma variant translocation 1 (PVT1) in VAN-induced AKI have been poorly defined till now. Protein levels of p65, phosphorylated p65 (p-p65), NF-κB inhibitor alpha (IκBα), phosphorylated IκBα (p-IκBα), Bcl-2 and Bax were measured by western blot assay. RNA levels of PVT1 and microRNA-124 (miR-124) were determined by RT-qPCR assay. HK-2 cell apoptosis was detected by an Annexin V-FITC apoptosis detection assay. Kidney functions were assessed by blood urea nitrogen (BUN) level, serum creatinine (Scr) level, histopathologic analysis, and TUNEL assay. Bioinformatical analysis, luciferase reporter assay, RIP and RNA pull down assays were performed to explore whether PVT1 could interact with miR-124. PVT1 was highly expressed in VAN-induced AKI models. Functional analysis revealed that PVT1 knockdown ameliorated VAN-induced AKI in vivo. Further exploration manifested that PVT1 directly interacted with miR-124. Moreover, the silencing of PVT1 abated VAN-induced HK-2 cell apoptosis in vitro, while this effect was reversed by the miR-124 inhibitor. Also, VAN treatment resulted in the reduction of miR-124 expression and the activation of NF-κB signaling in HK-2 cells. The inhibition of NF-κB alleviated VAN-induced HK-2 cell apoptosis. PVT1 activated NF-κB signaling by targeting miR-124 in VAN-induced HK-2 cells. PVT1 knockdown lessened VAN-induced AKI by targeting miR-124 via inactivating the NF-κB signaling, elucidating the critical roles and molecular basis of PVT1 in VAN-induced AKI and highlighting the diagnostic and therapeutic values of PVT1 in AKI.

PVT1 was highly expressed in the kidneys of VAN-induced AKI mice.

MicroRNA-124a inhibits cell proliferation and migration in liver cancer by regulating interleukin-11

Liver cancer is the sixth most common malignant tumour and ranks in the top three cancers with regard to mortality due to metastasis and postsurgical recurrence. It is significant to understand the mechanisms underlying liver cancer for diagnosis and treatment. Cumulative evidence suggests that the abnormal regulation of microRNAs (miRNAs/miRs) may contribute to the development and metastasis of cancer. miR‑124a acts as a tumour suppressor in osteosarcoma, endometrial carcinoma, prostate cancer, and glioblastoma. However, the effects of miR‑124a in liver cancer and its biological mechanism are not fully understood. It has been demonstrated that miR‑124a is downregulated and interleukin (IL)‑11 is upregulated in the liver cancer tissues. In the present study, miR‑124a upregulation inhibited cell proliferation, migration and promoted cell apoptosis. Through a dual‑luciferase reporter assay, it was verified that IL‑11 is a direct target of miR‑124a. Furthermore, the overexpression of miR‑124a repressed the secretion of IL‑11 from hepatoma cells. Finally, it was identified that mimics of miR‑124a increased the expression of tissue inhibitor of matrix metalloproteinase‑2 (TIMP‑2) and Caspase‑3 and decreased the expression levels of matrix metalloproteinase 2 (MMP2), MMP9, B‑cell lymphoma 2, signal transducer and activator of transcription 3 (STAT3), and phosphorylated‑STAT3. In conclusion, the results indicated that miR‑124a has an important role as a tumour suppressor gene by targeting IL‑11. These findings may provide novel insights for clinical treatments to prevent the development of liver cancer.

LncRNA HOXA11-AS promotes proliferation and invasion by targeting miR-124 in human non-small cell lung cancer cells

Long non-coding RNAs have been implicated in human cancer but their mechanisms of action are mainly undocumented. In this study, we found that HOXA11-AS expression was upregulated in non-small cell lung cancer tissues and cell lines. High levels of HOXA11-AS expression were correlated with larger tumor size and lymph node metastasis. Functional analysis revealed that HOXA11-AS promotes non-small cell lung cancer cell proliferation and invasion. In particular, HOXA11-AS functions as a competing endogenous RNA to regulate transcriptional factor Sp1 expression via sponging miR-124. Collectively, our findings reveal an oncogenic role for HOXA11-AS in non-small cell lung cancer tumorigenesis.

MicroRNA-326 inhibits cell proliferation and invasion, activating apoptosis in hepatocellular carcinoma by directly targeting LIM and SH3 protein 1

Hepatocellular carcinoma (HCC) is the fifth-most common cancer and third leading cause of cancer-related deaths worldwide. Increasing evidence indicates that dysregulation of microRNAs is often observed in HCC, and has been extensively investigated in terms of cancer formation, progression, diagnosis, therapy, and prognosis. Recently, microRNA-326 (miR-326) has been demonstrated to play important roles in multiple types of human cancer. However, the expression pattern, clinical significance, roles and regulatory mechanisms of miR-326 in HCC have yet to be elucidated. In this study, miR-326 was frequently downregulated in HCC tissues and cell lines. Low miR-326 expression was significantly associated with the TNM stage, differentiation and lymph node metastasis of HCC patients. Further functional assays demonstrated that the recovered miR-326 expression inhibited HCC cell proliferation and invasion and activated cell apoptosis in vitro. In addition, LIM and SH3 protein 1 (LASP1) was identified as a direct target gene of miR-326 in HCC. Furthermore, LASP1 was upregulated in HCC tissues and cell lines. The expression level of LASP1 mRNA was inversely correlated with that of miR-326 in HCC tissues. Moreover, LASP1 silencing elicited effects similar to miR-326 overexpression on HCC cells, and LASP1 upregulation markedly reversed the effects of miR-326 overexpression on HCC cells. These results revealed that miR-326 suppressed the progression of HCC by directly targeting LASP1. Therefore, miR-326 may be used as a potential therapeutic target for the treatment of patients with HCC.

High αv Integrin Level of Cancer Cells Is Associated with Development of Brain Metastasis in Athymic Rats

BACKGROUND/AIM

Brain metastases commonly occur in patients with malignant skin, lung and breast cancers resulting in high morbidity and poor prognosis. Integrins containing an αv subunit are cell adhesion proteins that contribute to cancer cell migration and cancer progression. We hypothesized that high expression of αv integrin cell adhesion protein promoted metastatic phenotypes in cancer cells.

MATERIALS AND METHODS

Cancer cells from different origins were used and studied regarding their metastatic ability and intetumumab, anti-αv integrin mAb, sensitivity using in vitro cell migration assay and in vivo brain metastases animal models.

RESULTS

The number of brain metastases and the rate of occurrence were positively correlated with cancer cell αv integrin levels. High αv integrin-expressing cancer cells showed significantly faster cell migration rate in vitro than low αv integrin-expressing cells. Intetumumab significantly inhibited cancer cell migration in vitro regardless of αv integrin expression level. Overexpression of αv integrin in cancer cells with low αv integrin level accelerated cell migration in vitro and increased the occurrence of brain metastases in vivo.

CONCLUSION

αv integrin promotes brain metastases in cancer cells and may mediate early steps in the metastatic cascade, such as adhesion to brain vasculature. Targeting αv integrin with intetumumab could provide clinical benefit in treating cancer patients who develop metastases.