miR-27a inhibits cervical adenocarcinoma progression by downregulating the TGF-βRI signaling pathway

Interplay between LncRNA/miRNA and TGF-β Signaling in the Tumorigenesis of Gynecological Cancer

Gynecologic cancers are among the most common malignancies with aggressive features and poor prognosis. Tumorigenesis in gynecologic cancers is a complicated process that is influenced by multiple factors, including genetic mutations that activate various oncogenic signaling pathways, including the TGF-β pathway. Aberrant activation of TGF-β signaling is correlated with tumor recurrence and metastasis. It has been shown that non-coding RNAs (ncRNAs) have crucial effects on cancer cell proliferation, migration, and metastasis. Upregulation of various ncRNAs, including long non-coding RNAs (lncRNA) and microRNAs (miRNAs), has been reported in several tumors, like cervical, ovarian, and endometrial cancers, but their cellular mechanisms remain to be investigated. Thus, recognizing the role of ncRNAs in regulating the TGF-β pathway may provide novel strategies for better treatment of cancer patients. The present study summarizes recent findings on the role of ncRNAs in regulating the TGF-β signaling involved in tumor progression and metastasis in gynecologic cancers.

miR‑27a‑3p upregulation by p65 facilitates cervical tumorigenesis by increasing TAB3 expression and is involved in the positive feedback loop of NF‑κB signaling

An altered microRNA (miRNA/miR)‑27a‑3p expression has been identified in cervical cancer, while the exact regulatory mechanisms responsible for the dysregulation of miR‑27a‑3p remain to be fully elucidated. In the present study, a NF‑κB/p65 binding site was identified upstream of the miR‑23a/27a/24‑2 cluster and p65 binding enhanced the transcription of pri‑miR‑23a/27a/24‑2, as well as the expression levels of mature miRNAs, including miR‑27a‑3p in HeLa cells. Mechanistically, using bioinformatics analyses and experimental validation, TGF‑β activated kinase 1 binding protein 3 (TAB3) was identified as a direct target of miR‑27a‑3p. By binding to the 3'UTR of TAB3, miR‑27a‑3p significantly enhanced TAB3 expression. Functionally, it was found that the overexpression of miR‑27a‑3p and TAB3 promoted the malignant potential of cervical cancer cells, as evaluated using cell growth, migration and invasion assays, and specific cell marker determinations in the epithelial mesenchymal transition progression, and vice versa. Further rescue experiments revealed that the enhanced malignant effects induced by miR‑27a‑3p were mediated via its upregulation of TAB3 expression. Moreover, miR‑27a‑3p and TAB3 also activated the NF‑κB signaling pathway and formed a positive feedback regulatory loop composing of p65/miR‑27a‑3p/TAB3/NF‑κB. On the whole, the findings presented herein may provide novel insight into the underlying cervical tumorigenesis and novel biomarker identification for clinical applications.

MiR-27a as a diagnostic biomarker and potential therapeutic target in systemic sclerosis

Systemic sclerosis (SSc) or scleroderma is a multiorgan rheumatoid disease characterized by skin tightening or organ dysfunction due to fibrosis, vascular damage, and autoimmunity. No specific cause has been discovered for this illness, and hence no effective treatment exists for it. On the other hand, due to the lack of diagnostic biomarkers capable of effectively and specifically differentiating the patients, early diagnosis has not been possible. Due to their potent regulatory roles in molecular pathways, microRNAs are among the novel candidates for the diagnosis and treatment of diseases like SSc. MiR-27a is a microRNA known for its role in the pathogenesis of fibrosis and cancer, both of which employ similar signaling pathways; hence we hypothesized that Mir-27a could be dysregulated in the blood of individuals affected by SSc and it might be useful in the diagnosis or treatment of this disease. Blood was collected from 60 SSc patients (30 limited and 30 diffuse) diagnosed by a rheumatologist according to ACR/AULAR criteria; following RNA isolation and cDNA synthesis; real-time qPCR was performed on the samples using Taq-Man probes and data were analyzed by the ΔΔCT method. Also, potential targets of miR-27a were evaluated using bioinformatics. It was revealed that miR-27a was significantly down-regulated in SSc patients in comparison to healthy individuals, but there was no difference in miR-27 expression between limited and diffused SSc patients. Besides, miR-27a was found to target several contributing factors to SSc. It seems that miR-27a has a protective role in SSc, and its downregulation could result in the disease's onset. Based on bioinformatics analyses, it is speculated that miR-27a likely targets factors contributing to the pathogenesis of SSc, which are elevated upon the downregulation of miR-27a; hence, miR-27a mimics could be considered as potential therapeutic agents for the treatment of SSc in future studies. Since no difference was observed between limited and diffuse patient groups, it is unlikely that this microRNA has a role in disease progression. According to ROC analysis of qPCR data, miR-27a could be employed as a valuable diagnostic biomarker for SSc.

MicroRNA-27a-5p Inhibits Proliferation, Migration, and Invasion and Promotes Apoptosis of Wilms' Tumor Cell by Targeting PBOV1

Wilms' tumor is the most common type of renal tumor in children. MicroRNAs (miRNAs) are small noncoding RNAs that play crucial regulatory roles in tumorigenesis. We aimed to study the expression profile and function of miR-27a-5p in Wilms' tumor. miR-27a-5p expression was downregulated in human Wilms' tumor tissues. Functionally, overexpression of miR-27a-5p promoted cell apoptosis of Wilms' tumor cells. Furthermore, upregulated miR-27a-5p delayed xenograft Wilms' tumor tumorigenesis in vivo. Bioinformatics analysis predicted that miR-27a-5p directly targeted the 3'-untranslated region (3'-UTR) of PBOV1, and luciferase reporter assay confirmed the interaction between miR-27a-5p and PBOV1. The function of PBOV1 in Wilms' tumor was evaluated in vitro, and knockdown of PBOV1 dampened cell migration. In addition, overexpression of PBOV1 antagonized the tumor-suppressive effect of miR-27a-5p in Wilms' tumor cells. Collectively, our findings reveal the regulatory axis of miR-27a-5p/PBOV1 in Wilms' tumor, and miR-27a-5p might serve as a novel therapeutic target in Wilms' tumor.

Role of miR-27a in the regulation of cellular function via the inhibition of MAP2K4 in patients with asthma

Asthma is a respiratory disease with a clinically high incidence, and repeated attacks of asthma severely affect the quality of life and even pose a threat to health, leading to severe burdens on families and even the society. A thorough understanding of the pathogenesis of asthma is essential for the prevention and treatment of asthma. This study aimed to examine the effect of the microRNA miR-27a on asthma and its relationship with mitogen activated protein kinase 4 (MAP2K4). Patients with asthma admitted to our hospital from August 2016 to August 2018 and healthy participants in the same period were included in this prospective analysis. The mRNA expression levels of miR-27a and MAP2K4 in peripheral blood were determined. Airway smooth muscle cells (ASMCs) were used to study the effects of miR-27a and MAP2K4 on cell biological behavior. The relationship between miR-27a and MAP2K4 was verified using dual-luciferase reporter assay. miR-27a expression was increased and MAP2K4 mRNA expression was decreased in asthma (P < 0.05). Increasing miR-27a expression and inhibiting MAP2K4 expression could enhance the activity of ASMCs, whereas inhibiting miR-27a expression and increasing MAP2K4 expression had the opposite effect (P < 0.05). Dual-luciferase reporter assay results showed that the fluorescence activity of MAP2K4-wild type was inhibited by increased miR-27a expression (P < 0.05). miR-27a promotes the proliferation and invasion of ASMCs by targeting MAP2K4 and is involved in the occurrence of asthma.

Data Integration Using Tensor Decomposition for The Prediction of miRNA-Disease Associations

Dysfunction of miRNAs has an important relationship with diseases by impacting their target genes. Identifying disease-related miRNAs is of great significance to prevent and treat diseases. Integrating information of genes related miRNAs and/or diseases in calculational methods for miRNA-disease association studies is meaningful because of the complexity of biological mechanisms. Therefore, in this study, we propose a novel method based on tensor decomposition, termed TDMDA, to integrate multi-type data for identifying pathogenic miRNAs. First, we construct a three-order association tensor to express the associations of miRNA-disease pairs, the associations of miRNA-gene pairs, and the associations of gene-disease pairs simultaneously. Then, a tensor decomposition-based method with auxiliary information is applied to reconstruct the association tensor for predicting miRNA-disease associations, and the auxiliary information includes biological similarity information and adjacency information. The performance of TDMDA is compared with other advanced methods under 5-fold cross-validations. The experimental results indicate the TDMDA is a competitive method.

Overexpressed miR-375-Loaded Restrains Development of Cervical Cancer Through Down-Regulation of Frizzled Class Receptor 4 (FZD4) with Liposome Nanoparticle as a Carrier

Dysregulation expression of miR-375 is noted to correlate with progression of cervical cancer. This study attempted to investigate the impact of overexpressed miR-375-loaded liposome nanoparticles on proliferation of cervical cancer (CC), to provide an insight on pathogenesis of CC disorder. CC cells were co-cultured with pure liposome nanoparticles (empty vector group), miR-375 agonist-loaded liposome nanoparticles, or transfected with miR-375 antagonist. Besides, some cells were exposed to TGF-β/Smads signaling pathway inhibitor or activator whilst cell proliferation was assessed by MTT assay, and expressions of FZD4 and miR-375 were determined. Western blot analysis was carried out to detect the expression of TGF-β pathway factors (TGF-β, Smad2, Smad7, p-Smad2) and its downstream Smads pathway. The interaction between miR-375 and FZD4 was evaluated by dual-luciferase reporter gene assay. Overexpression of miR-375 induced arrest at the G0/G1 phase of cell cycle and elevation of Smad2 protein expression (P <0.05), with lower expressions of TGF-β, Smad7, p-Smad2, and FZD4, while transfection with miR-375 inhibitor exhibited opposite activity. Presence of miR-375 agonist-loaded liposome nanoparticles induced decreased cell proliferation. There was a targeting relationship between miR-375 and FZD4, and administration with TGF-β/Smads agonist resulted in increased miR-375 and Smad2 expressions, as well as decreased TGF-β, Smad7, p-Smad2, FZD4 protein expression, and the number of S phase and G2/M phase cells (P < 0.05). The signaling inhibitor oppositely suppressed cell proliferation decreasing miR-375 expression. miR-375-loaded liposome nanoparticles activated TGF-β/Smads signaling pathway to restrain cell cycle and suppress cell division, and proliferation through targeting FZD4 in CC. Its molecular mechanism is related to activation of TGF-β/Smads signaling pathway.

miRNA Regulation of Glutathione Homeostasis in Cancer Initiation, Progression and Therapy Resistance

Glutathione (GSH) is the most abundant antioxidant that contributes to regulating the cellular production of Reactive Oxygen Species (ROS) which, maintained at physiological levels, can exert a function of second messengers in living organisms. In fact, it has been demonstrated that moderate amounts of ROS can activate the signaling pathways involved in cell growth and proliferation, while high levels of ROS induce DNA damage leading to cancer development. Therefore, GSH is a crucial player in the maintenance of redox homeostasis and its metabolism has a role in tumor initiation, progression, and therapy resistance. Our recent studies demonstrated that neuroblastoma cells resistant to etoposide, a common chemotherapeutic drug, show a partial monoallelic deletion of the locus coding for miRNA 15a and 16-1 leading to a loss of these miRNAs and the activation of GSH-dependent responses. Therefore, the aim of this review is to highlight the role of specific miRNAs in the modulation of intracellular GSH levels in order to take into consideration the use of modulators of miRNA expression as a useful strategy to better sensitize tumors to current therapies.

Lack of Conserved miRNA Deregulation in HPV-Induced Squamous Cell Carcinomas

Squamous cell carcinomas (SCCs) in the anogenital and head and neck regions are associated with high-risk types of human papillomaviruses (HR-HPV). Deregulation of miRNA expression is an important contributor to carcinogenesis. This study aimed to pinpoint commonly and uniquely deregulated miRNAs in cervical, anal, vulvar, and tonsillar tumors of viral or non-viral etiology, searching for a common set of deregulated miRNAs linked to HPV-induced carcinogenesis. RNA was extracted from tumors and nonmalignant tissues from the same locations. The miRNA expression level was determined by next-generation sequencing. Differential expression of miRNAs was calculated, and the patterns of miRNA deregulation were compared between tumors. The total of deregulated miRNAs varied between tumors of different locations by two orders of magnitude, ranging from 1 to 282. The deregulated miRNA pool was largely tumor-specific. In tumors of the same location, a low proportion of miRNAs were exclusively deregulated and no deregulated miRNA was shared by all four types of HPV-positive tumors. The most significant overlap of deregulated miRNAs was found between tumors which differed in location and HPV status (HPV-positive cervical tumors vs. HPV-negative vulvar tumors). Our results imply that HPV infection does not elicit a conserved miRNA deregulation in SCCs.

Role and clinical significance of TGF‑β1 and TGF‑βR1 in malignant tumors (Review)

The appearance and growth of malignant tumors is a complicated process that is regulated by a number of genes. In recent years, studies have revealed that the transforming growth factor-β (TGF-β) signaling pathway serves an important role in cell cycle regulation, growth and development, differentiation, extracellular matrix synthesis and immune response. Notably, two members of the TGF-β signaling pathway, TGF-β1 and TGF-β receptor 1 (TGF-βR1), are highly expressed in a variety of tumors, such as breast cancer, colon cancer, gastric cancer and hepatocellular carcinoma. Moreover, an increasing number of studies have demonstrated that TGF-β1 and TGF-βR1 promote proliferation, migration and epithelial-mesenchymal transition of tumor cells by activating other signaling pathways, signaling molecules or microRNAs (miRs), such as the NF-κB signaling pathway and miR-133b. In addition, some inhibitors targeting TGF-β1 and TGF-βR1 have exhibited positive effects in in vitro experiments. The present review discusses the association between TGF-β1 or TGF-βR1 and tumors, and the development of some inhibitors, hoping to provide more approaches to help identify novel tumor markers to restrain and cure tumors.

Dysregulated LncRNAs Act as Competitive Endogenous RNAs and Are Associated With Cervical Cancer Development in UYGHUR Women

Cervical cancer is one of the most malignant tumors in women, particularly those in rural and remote areas. Its underlying molecular mechanisms, including the functions of non-coding RNA (ncRNAs), require more extensive investigation. In this study, high throughput transcriptome sequencing (RNA-seq) was used to identify differentially expressed lncRNAs and mRNAs in normal, cervical intraepithelial neoplasia and cervical cancer tissues from Uyghur women in western China. Dysregulated lncRNAs were found to extensively participate in cervical cancer development, including viral carcinogenesis, cell cycle and cytokine-cytokine receptor signaling. Two miRNA-host lncRNAs, LINC00925 and MIR155HG, showed elevated expression in cervical cancer samples, but prolonged the survival time of cervical cancer patients. The 2 mature miRNAs of the above 2 lncRNAs, miR-9 and miR-155, also showed similar features in cervical cancer. In addition, we identified 545 lncRNAs with potential functions in regulating these 2 miRNAs as competing endogenous RNAs (ceRNAs). In summary, our study demonstrated the dysregulated lncRNAs/miRNAs, particularly LINC00925/miR-9 and MIR155HG/miR-155, regulate the development of cervical cancer by forming a interaction network with mRNAs, highlighting the importance of elucidating the underlying mechanisms of ncRNAs in cervical cancer development.

Hsa-miR-27a-3p overexpression in men with nonobstructive azoospermia: A case-control study

Background

The role of KDM3A and its downstream genes in male fertility has been approved in animal models. Additionally, the expression shrinkage of KDM3A is significantly correlated with human azoospermia phenotype. Aberrant expression of micro-RNAs could mislead spermatogenesis and mostly lead to diverse phenotypes of male infertility.

Objective

The aim of this study was to evaluate the expression level of hsa-miR-27a-3p in azoospermic men to reveal its possible association with infertility.

Materials and Methods

This case-control study was conducted on 30 azoospermic men, of whom, 19 had non obstructive azoospermia (NOA) and 11 obstructive azoospermia (OA) according to the pathological examinations. Comprehensive bioinformatics investigations were performed securely and hsa-miR-27a-3p was selected afterward. Reverse Transcriptase-quantitative polymerase chain reaction (RT-qPCR) method was used and statistical analysis was performed to compare the expression level of hsa-miR-27a-3p in both OA and NOA individuals.

Results

In silico analysis suggested hsa-miR-27a-3p, with its potential binding ability to target KDM3A transcripts. The expression analysis of candidate hsa-miR-27a-3p indicated its significant overexpression in NOA men.

Conclusion

The hsa-miR-27a-3p was overexpressed in NOA men compared to OA-control individuals. As a consequence, the overexpressed micro-RNA could downregulate directly KDM3A and indirectly TNP1 and PRM1. Therefore, spermatogenesis could be misled and male infertility could be developed.

Uncovering the expression patterns and the clinical significance of miR-182, miR-205, miR-27a and miR-369 in patients with urinary bladder cancer

BACKGROUND

Given the high recurrence and progression rates and the absence of reliable markers for early detection and prognosis prediction of patients with urothelial bladder cancer (BCa), the exploration of new biomarkers with high specificity is imperative. Mainly, microRNAs (miRNAs), which are involved in the initiation and the progression of BCa. Herein, the expression patterns of miR-182, miR-205, miR-27a and miR-369 were evaluated in patients with urothelial BCa.

METHODS AND RESULTS

The expression levels of the miRNAs were investigated in 90 FFPE tissue samples (23 LG NMIBC, 44 HG NMIBC, 23 MIBC) and 10 non tumoral bladder tissues using TaqMan based RT-qPCR. Data analysis was performed using 2^-ΔΔCT method. Correlation to clinical characteristics of the patients was performed using descriptive statistics and the receiver operating characteristic (ROC) curve was performed to evaluate the diagnostic value of all miRNAs. MiR-27a, miR-205 and miR-369 were down-regulated whereas miR-182 was up-regulated in patients compared to controls (p < 0.001). MiR-205 and miR-182 positively segregate between NMIBC and MIBC (p = 0.002 and p = 0.000 respectively) whereas the distribution of miR-27a's expression among these tumor groups was almost significant (p = 0.05) and that of miR-369's expression was irrelevant (p = 0.618). Interestingly, miR-182 was discriminative between LG NMIBC and HG NMIBC (p < 0.001) and Ta/T1 tumors (p = 0.000). Furthermore, high levels of miR-182 were potentially predictive of progression in NMIBC patients (p = 0.01).

CONCLUSION

Collectively, a selection of miRNAs was found to be aberrantly expressed in BCa suggesting a potential diagnostic value in BCa. In addition, the clinical value of miR-182 and miR-205 as potential prognosis biomarkers was highlighted. Indeed, our data provide additional insights into cancer biology. Further functional or target studies are mandatory to strengthen these findings.

Transcriptome analysis uncovers the diagnostic value of miR-192-5p/HNF1A-AS1/VIL1 panel in cervical adenocarcinoma

Despite the fact that the incidence of cervical squamous cell carcinoma has decreased, there is an increase in the incidence of cervical adenocarcinoma. However, our knowledge on cervical adenocarcinoma is largely unclear. Transcriptome sequencing was conducted to compare 4 cervical adenocarcinoma tissue samples with 4 normal cervical tissue samples. mRNA, lncRNA, and miRNA signatures were identified to discriminate cervical adenocarcinoma from normal cervix. The expression of VIL1, HNF1A-AS1, MIR194-2HG, SSTR5-AS1, miR-192-5p, and miR-194-5p in adenocarcinoma were statistically significantly higher than that in normal control samples. The Receiver Operating Characteristic (ROC) curve analysis indicated that combination of miR-192-5p, HNF1A-AS1, and VIL1 yielded a better performance (AUC = 0.911) than any single molecule -and could serve as potential biomarkers for cervical adenocarcinoma. Of note, the combination model also gave better performance than TCT test for cervical adenocarcinoma diagnosis. However, there was no correlation between miR-192-5p or HNF1A-AS1 and HPV16/18 E6 or E7. VIL1 was weakly correlated with HPV18 E7 expression. In summary, our study has identified miR-192-5p/HNF1A-AS1/VIL1 panel that accurately discriminates adenocarcinoma from normal cervix. Detection of this panel may provide considerable clinical value in the diagnosis of cervical adenocarcinoma.

Nucleic Acid-Based Approaches for Tumor Therapy

Within the last decade, the introduction of checkpoint inhibitors proposed to boost the patients' anti-tumor immune response has proven the efficacy of immunotherapeutic approaches for tumor therapy. Furthermore, especially in the context of the development of biocompatible, cell type targeting nano-carriers, nucleic acid-based drugs aimed to initiate and to enhance anti-tumor responses have come of age. This review intends to provide a comprehensive overview of the current state of the therapeutic use of nucleic acids for cancer treatment on various levels, comprising (i) mRNA and DNA-based vaccines to be expressed by antigen presenting cells evoking sustained anti-tumor T cell responses, (ii) molecular adjuvants, (iii) strategies to inhibit/reprogram tumor-induced regulatory immune cells e.g., by RNA interference (RNAi), (iv) genetically tailored T cells and natural killer cells to directly recognize tumor antigens, and (v) killing of tumor cells, and reprograming of constituents of the tumor microenvironment by gene transfer and RNAi. Aside from further improvements of individual nucleic acid-based drugs, the major perspective for successful cancer therapy will be combination treatments employing conventional regimens as well as immunotherapeutics like checkpoint inhibitors and nucleic acid-based drugs, each acting on several levels to adequately counter-act tumor immune evasion.

APE1 promotes proliferation and migration of cutaneous squamous cell carcinoma

BACKGROUND

Human Apurinic/Apyrimidinic Endonuclease 1 (APE1/REF-1/HAP1) is a multifunction protein involved in the progression of cancer. But the role of APE1 in cutaneous squamous cell carcinoma (cSCC) is unclear.

OBJECTIVE

This study is aimed to investigate the basic modulatory mechanism of APE1 in cSCC development and offer a novel potential target for clinical treatment.

METHODS

The expression of APE1 in cSCC tissues was detected by western blot and immunohistochemistry (IHC) staining. The function of APE1 and miR-27a in cSCC cells was investigated by cell counting kit-8 (CCK-8) assays, colony formation assays and transwell migration assays. Western blot was used to determine the expression of APE1 in cSCC and epithelial-mesenchymal transition (EMT) markers in HSC-1 and HSC-5 cells with APE1 knockdown or overexpression. Double luciferase reporter assays were performed to confirm the interaction of miR-27a and APE1.

RESULTS

We identified that APE1 was significantly upregulated in human cSCC tissues and cSCC cells and its overexpression promoted cell proliferation, migration and the expression of EMT markers in cSCC cells. Mechanistically, miR-27a was predicted and confirmed as the upstream of APE1. Its downregulation also enhanced the proliferation and migration of cSCC cells. Rescue experiments demonstrated that restoration of APE1 expression significantly abolished the inhibition of cell proliferation and migration mediated by miR-27a.

CONCLUSION

As a direct gene of miR-27a, APE1 improved cell proliferation and migration to promote the progression of cSCC, which could be considered as a potential therapeutic target for cSCC treatment.

Protective role of microRNA-27a upregulation and HSP90 silencing against cerebral ischemia-reperfusion injury in rats by activating PI3K/AKT/mTOR signaling pathway

OBJECTIVE

MicroRNAs (miRNAs) have been reported in cerebral ischemia-reperfusion injury, yet the function of miR-27a in it has seldom been mentioned. This study aims to assess the mechanisms of miR-27a in rats with cerebral ischemia-reperfusion injury.

METHODS

The cerebral ischemia-reperfusion models of rat pups were established by bilateral carotid artery occlusion. Rats were treated with miR-27a agomir, silenced HSP90 expression plasmids or PI3K/AKT/mTOR pathway agonist. Oxidative stress indices, inflammatory factors, brain tissue water content, cerebral infarct volume, neurological function score and neuronal apoptosis in rats with cerebral ischemia-reperfusion injury were measured. MiR-27a and HSP90 expression and PI3K/AKT/mTOR phosphorylation levels in the brain tissues of rats were also detected.

RESULTS

MiR-27a expression and PI3K/AKT/mTOR phosphorylation levels were downregulated while HSP90 expression was upregulated in cerebral ischemia-reperfusion injury rats. Elevated miR-27a or reduced HSP90 diminished water content, neuronal apoptosis and infarct volume, suppressed oxidative stress and inflammatory response, as well as improved neurological deficits and pathological damages. Moreover, elevated miR-27a or silenced HSP90 upregulated PI3K/AKT/mTOR phosphorylation levels in cerebral ischemia-reperfusion injury rats. HSP90 silencing or PI3K/AKT/mTOR pathway agonist reversed the unfavorable effects of low miR-27a expression on cerebral ischemia-reperfusion injury rats.

CONCLUSION

To conclude, our study demonstrates that elevated miR-27a or decreased HSP90 attenuates oxidative stress and inflammatory response, and improves neurological function in cerebral ischemia-reperfusion injury rats by activating PI3K/AKT/mTOR signaling pathway.

Dysregulation of Stemness Pathways in HPV Mediated Cervical Malignant Transformation Identifies Potential Oncotherapy Targets

Human papillomavirus (HPV) infection is associated with a range of malignancies that affect anogenital and oropharyngeal sites. α-HPVs dominantly infect basal epithelial cells of mucosal tissues, where they dysregulate cell division and local immunity. The cervix is one of the mucosal sites most susceptible to HPV infections. It consists of anatomically diverse regions, and the majority of cervical intraepithelial neoplasia and cancers arise within the cervical squamo-columnar junction where undifferentiated basal progenitor cells with stem cell properties are found. The cancer stem cell theory particularly associates tumorigenesis, invasion, dissemination, and metastasis with cancer cells exhibiting stem cell properties. In this perspective, we discuss evidence of a cervical cancer stem cell niche and explore the association of stemness related genes with 5-year survival using a publicly available transcriptomic dataset of a cervical cancer cohort. We report that poor prognosis in this cohort correlates with overexpression of a subset of stemness pathway genes, a majority of which regulate the central Focal Adhesion pathway, and are also found to be enriched in the HPV infection pathway. These observations support therapeutic targeting of stemness genes overexpressed by mucosal cells infected with high-risk HPVs.

Folate inhibits miR-27a-3p expression during cervical carcinoma progression and oncogenic activity in human cervical cancer cells

BACKGROUND

Folate deficiency has been long implicated in cancer development. Although the role of folate in preventing cervical cancer is still unclear, emerging evidence shows that microRNAs (miRs) have great influence on tumor cell migration and invasion.

OBJECTIVES

The purpose of this study was to conduct an integrated analysis of miR expression in squamous cell carcinoma tissues with adequate or deficient serum folate. Further, study conducted tissue validation and functional analysis of miRs to uncover novel pathogenic mechanisms on the role of folate in squamous cell carcinoma (SCC).

MATERIALS AND METHODS

miR expression profiles were obtained from five paired primary SCC tumors with sufficient or deficient serum folate levels through Affymetrix GeneChip microRNA 4.0. This was followed by an integrated bioinformatics analysis and expanded sample size to verify core miRs by molecular biological validation. HeLa and SiHa cells with different concentrations of folate were used to clarify the roles of miR-27a on cell proliferation, migration, and invasion. MiR-27a expression was measured by the quantitative real-time polymerase chain reaction. Cell counting proliferation, wound healing, and transwell invasion assays were used to determine cell survival, proliferation, migration, and invasion abilities, respectively.

RESULTS

Our study found increasing miR-27a expression in serum of normal, high-grade squamous intraepithelial lesion (HSIL), and SCC tissues (in order of magnitude), which trend was negatively correlated with serum folate content. Further, there were significant differences in cellular miR-27a expression between 200 nM and 500 nM folate concentrations, with higher folate concentrations showing lower proliferation, migration, and invasion in SCC. Finally, miR-27a promoted proliferation and invasion in HeLa cells, whereas a miR-27a inhibitor blocked cell proliferation and invasion.

CONCLUSION

There is a significant association between miR-27a expression and folate during cervical carcinoma progression. Therefore, miR-27a could be used as a new biomarker for SCC diagnosis and prediction, suggesting a new therapeutic strategy for SCC treatment.

Inhibiting miR-27a and miR-142-5p attenuate nonalcoholic fatty liver disease by regulating Nrf2 signaling pathway

The gene Nrf2 (nuclear factor-erythroid 2-related factor 2) is the most important regulator of the cellular antioxidant system and its dysregulation has a role in the etiology of nonalcoholic fatty liver disease (NAFLD). The aim of this study was to investigate the association between Nrf2 targeted miRNAs (miR-27a, miR-142-5p, miR-153, and miR-128) with lipid accumulation in vitro and in vivo models of NAFLD. We used two in vivo and in vitro models of NAFLD. The expression of the genes and miRNAs was assessed by real-time PCR and the protein level was evaluated using western blot. To investigate the potential role of miRNAs in NAFLD, the inhibitors or mimics of the miR-27a and miR-142-5p were transfected into HepG2 cells. The mRNA and protein levels of Nrf2 were significantly decreased in the liver of high fat diet-fed mice as well as in HepG2 cells treated with high glucose (HG). Reduced expression of Nrf2 was associated with increased expression levels of miR-27a and miR-142-5p in both models of NAFLD. HG-induced triglyceride accumulation was attenuated by inhibition of miR-27a or miR-142-5p in HepG2 cells. Overexpression of miR-27a or miR-142-5p suppressed the expression of Nrf2 and its downstream antioxidant genes and increased production of reactive oxygen species, whereas inhibition of miR-27a or miR-142-5p reversed these effects. In conclusion, the data of this study may suggest that miR-27a and miR-142-5p are increased in NAFLD, where they suppress Nrf2 expression and contribute to the accumulation of lipids in the hepatocytes.

Regulatory effect of hsa-miR-5590-3P on TGFβ signaling through targeting of TGFβ-R1, TGFβ-R2, SMAD3 and SMAD4 transcripts

Transforming growth factor-β (TGFβ) signaling acts as suppressor and inducer of tumor progression during the early and late stages of cancer, respectively. Some miRNAs have shown a regulatory effect on TGFβ signaling and here, we have used a combination of bioinformatics and experimental tools to show that hsa-miR-5590-3p is a regulator of multiple genes expression in the TGFβ signaling pathway. Consistent with the bioinformatics predictions, hsa-miR-5590-3p had a negative correlation of expression with TGFβ-R1, TGFβ-R2, SMAD3 and SMAD4 genes, detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Then, the dual luciferase assay supported the direct interaction between hsa-miR-5590-3p and TGFβ-R1, TGFβ-R2, SMAD3 and SMAD4-3'UTR sequences. Consistently, the TGFβ-R1 protein level was reduced following the overexpression of hsa-miR-5590-3p, detected by Western analysis. Also, hsa-miR-5590-3p overexpression brought about the downregulation of TGFβ-R1, TGFβ-R2, SMAD3 and SMAD4 expression in HCT-116 cells, detected by RT-qPCR, followed by cell cycle arrest in the sub-G1 phase, detected by flow cytometry. RT-qPCR results indicated that hsa-miR-5590-3p is significantly downregulated in breast tumor tissues (late stage) compared to their normal pairs. Altogether, data introduces hsa-miR-5590-3p as a negative regulator of the TGFβ/SMAD signaling pathway which acts through downregulation of TGFβ-R1, TGFβ-R2, SMAD3 and SMAD4 transcripts. Therefore, it can be tested as a therapy target in cancers in which the TGFβ/SMAD pathway is deregulated.

Click RNA for Rapid Capture and Identification of Intracellular MicroRNA Targets

Rapid capture and identification of the intracellular target genes of microRNAs (miRNAs) are the key to understanding miRNA functions and development of RNA-based therapeutics. However, developing biochemical tools that can fish out the target genes of miRNAs in live cells is a significant technical challenge. Here, we report a remarkably simple yet powerful technology capable of loading virtually any miRNA into Ago2 of the RNA-induced silencing complexes (RISCs). This surprising discovery enables rapid capture and identification of target mRNAs and long noncoding RNAs. It is achieved by linking dibenzocyclooctyne (DBCO), a classical chemical moiety in copper-free click chemistry, to the 3' end of miRNAs. DBCO serves as a high-affinity tag to the Ago2 protein, thus boosting the formation of RISCs with miRNA target genes in living cells. Upon cell lysing, DBCO's routine function in click chemistry allows rapid enrichment of target genes for analysis without the need of additional molecular handles. A series of miR-21 and miR-27a target genes that were previously unknown were pulled down from various cell lines and identified with qRT-PCR, demonstrating the utility of this innovative technology in both transcriptomic research and RNA-based studies.

MicroRNA-27a (miR-27a) in Solid Tumors: A Review Based on Mechanisms and Clinical Observations

MicroRNAs (miRNAs) are a family of highly conserved, non-coding single-stranded RNAs transcribed as ~70 nucleotide precursors to an 18–22 nucleotide product (1). miRNAs can silence their homologous target genes at the post-transcriptional level, and these genes have been revealed to play an important role in tumorigenesis, invasion and metastasis (2). MicroRNA-27a (miR-27a), transcripted by miR-27a gene, has proved to implicate with many kinds of solid tumors, showing potential as a useful biomarker or drug target for clinical application. However, even though miR-27a has been reported in many cancers, the mechanism and signal pathways of miR-27 in oncogenesis, invasion, and metastasis are still obscure. Moreover, recent studies show that miR-27a pays an important role in epithelial-mesenchymal-transition, regulating tumor immune response, and chemoresistance. In this review, we summarize the current literature, demonstrate the established link between miR-27a and tumorigenesis, and focus on recently identified mechanisms. The review also aims to demonstrate the potential of miR-27a as a diagnostic and/or prognostic biomarker in solid tumors and to discuss the possibilities of targeted therapy and drug design.

Human Papilloma Virus-Associated Cervical Cancer and Health Disparities

Cervical cancer develops through persistent infection with high-risk human papilloma virus (hrHPV) and is a leading cause of death among women worldwide and in the United States. Periodic surveillance through hrHPV and Pap smear-based testing has remarkably reduced cervical cancer incidence worldwide and in the USA. However, considerable discordance in the occurrence and outcome of cervical cancer in various populations exists. Lack of adequate health insurance appears to act as a major socioeconomic burden for obtaining cervical cancer preventive screening in a timely manner, which results in disparate cervical cancer incidence. On the other hand, cervical cancer is aggressive and often detected in advanced stages, including African American and Hispanic/Latina women. In this context, our knowledge of the underlying molecular mechanism and genetic basis behind the disparate cervical cancer outcome is limited. In this review, we shed light on our current understanding and knowledge of racially disparate outcomes in cervical cancer.

Overexpression of mircoRNA-137 inhibits cervical cancer cell invasion, migration and epithelial-mesenchymal transition by suppressing the TGF-β/smad pathway via binding to GREM1

Background

Accumulating evidence has highlighted the tumor suppressive roles of microRNA (miRNAs) in cervical cancer (CC). In the present study, we aim to delineate the functional relevance of microRNA-137 (miR-137) in influencing epithelial-mesenchymal transition (EMT), and other CC cell biological activities via the TGF-β/smad pathway by binding to GREM1.

Methods

Microarray analysis was initially adopted to predict the differentially expressed genes and the miRNAs related to CC, followed by the measurement of the expression patterns of GREM1, EMT-related factors in the CC tissues and the adjacent tissues. Dual luciferase reporter gene assay was conducted to determine the relationship between miR-137 and GREM1. Gain-of- and loss-of-function experiments were conducted to characterize the effects of miR-137 and GREM1 on the colony formation, proliferation, apoptosis, migration, and invasion of CC cells in vitro, and the tumorigenicity of the CC cells in nude mice. The TGF-β/smad pathway was subsequently blocked with si-TGF-β to investigate its involvement.

Results

Reduced miR-137 expression and increased GREM1 expression were predicted in CC, which was subsequently observed in the CC tissues and cells. Notably, GREM1 was a target gene of miR-137. The overexpressed miR-137 was found to inhibit EMT, cell proliferation, colony formation, invasion, migration and tumorigenesis in nude mice. In addition, miR-137 was noted to inhibit the activation of the TGF-β/smad pathway by binding to GREM1. The silencing of TGF-β1 was shown to reverse the effects induced by downregulated expression of miR-137.

Conclusions

This study suggests that upregulated miR-137 suppresses the tumor progression in CC via blocking the TGF-β/smad pathway by binding to and negatively regulating GREM1.

Retracted Article: MiR-148a agomir based targeting of c-Met and Her-3 is able to attenuate EGFR-T790M mutation driven gefitinib and erlotinib resistance in non-small cell lung cancer cells

MiR-148a inhibits NSCLC progression. Whether miR-148a would reduce EGFR tyrosine kinase inhibitor (TKI) resistance of NSCLC cells remains underexplored. In this study, 5 NSCLC patients received surgery and gefitinib treatment but developed pleural metastasis. Patients' NSCLC adopted EGFR T790M mutation. 5 naïve and 5 gefitinib-resisting NSCLC cell lines were derived from patients primary and metastatic tumor tissues, and the 5 gefitinib-resisting NSCLC cell lines were trained with erlotinib to establish the erlotinib-resisting cell lines. MiR-148a levels in cells were analyzed by qRT-PCR. miR-148a overexpression was mimicked by agomir treatment. NSCLC cell malignancy was evaluated by cell proliferation, apoptosis, colony formation and transwell invasion assays. Protein levels of c-Met, Her-3 and IGF-1R were assessed by western blotting. miRNA-mRNA interaction was investigated by luciferase reporter assay and AGO2-RIP. Transient overexpression of MET, ERBB3 or IGF1R gene was achieved by plasmid transfection. Results showed that the MiR-148a level was decreased with the development of gefitinib and erlotinib resistance and that there was an increase in malignancy in NSCLC cells in vitro. Treatment with miR-148a agomir significantly enhanced the cytotoxicity of gefitinib and erlotinib to naïve, gefitinib-resisting and erlotinib-resisting NSCLC cells in vitro while reducing their protein levels of c-Met, Her-3 and IGF-1R, the mRNAs of which were verified as direct targets of miR-148a in NSCLC cells. Restoring c-Met or Her-3 protein levels partially reduced the gefitinib and erlotinib sensitizing effect of miR-148a agomir treatment on NSCLC cells. We concluded that MiR-148a attenuated gefitinib and erlotinib resistance in non-small cell lung cancer cells with EGFR T790M mutation by targeting c-Met and Her-3 expression.

MiR-148a inhibits NSCLC progression.

Transforming growth factor-β signaling: Tumorigenesis and targeting for cancer therapy

Transforming growth factor (TGF)-β is a multitasking cytokine such that its aberrant expression is related to cancer progression and metastasis. TGF-β is produced by a variety of cells within the tumor microenvironment (TME), and it is responsible for regulation of the activity of cells within this milieu. TGF-β is a main inducer of epithelial-mesenchymal transition (EMT), immune evasion, and metastasis during cancer progression. TGF-β exerts most of its functions by acting on TβRI and TβRII receptors in canonical (Smad-dependent) or noncanonical (Smad-independent) pathways. Members of mitogen-activated protein kinase, phosphatidylinositol 3-kinase/protein kinase B, and nuclear factor κβ are involved in the non-Smad TGF-β pathway. TGF-β acts by complex signaling, and deletion in one of the effectors in this pathway may influence the outcome in a diverse way by taking even an antitumor role. The stage and the type of tumor (contextual cues from cancer cells and/or the TME) and the concentration of TGF-β are other important factors determining the fate of cancer (progression or repression). There are a number of ways for targeting TGF-β signaling in cancer, among them the special focus is on TβRII suppression.

Upregulated miR-1258 regulates cell cycle and inhibits cell proliferation by directly targeting E2F8 in CRC

OBJECTIVES

MicroRNAs (miRNAs) as small noncoding RNA molecules function by regulating their target genes negatively. MiR-1258 was widely researched in multicancers, but its role remains unclear in colorectal cancer (CRC).

METHODS

The expression of miR-1258 and its specific target gene were detected in human CRC specimens and cell lines by miRNA RT-PCR, qRT-PCR and Western blot. The effects of miR-1258 on CRC proliferation were evaluated using CCK-8 assays, EdU incorporation, colony formation assays and cell-cycle assays; in vitro and the in vivo effects were investigated using a mouse tumorigenicity model. Luciferase reporter and RIP assays were employed to identify interactions between miR-1258 and its specific target gene.

RESULTS

MiR-1258 was downregulated in CRC tissues and CRC cell lines, and upregulated miR-1258 was proved to inhibit proliferation and arrest cell cycle at G0/G1 in vitro and vivo. Luciferase reporter, RIP and western blot assays revealed E2F8 to be a direct target of miR-1258. The effects of miR-1258 in proliferation and cell cycle regulation can be abolished by E2F8 through rescue experiments. By directly targeting E2F8, miR-1258 influenced the expression of several cell-cycle factors, including cyclin D1 (CCND1) and cyclin dependent kinase inhibitor 1A (p21).

CONCLUSION

MiR-1258 may function as a suppressive factor by negatively controlling E2F8, thus, highlighting the potential role of miR-1258 as a therapeutic target for human CRC.

Integrated microarray meta-analysis identifies miRNA-27a as an oncogene in ovarian cancer by inhibiting FOXO1

AIMS

Survival of ovarian cancer patients is generally poor, partly because most of them are already at an advanced stage when diagnosed. The purpose of this study was to screen prognostic miRNAs for ovarian cancer, and to explore the underlying mechanisms.

MAIN METHODS

Integrated meta-analysis of miRNA microarrays retrieved from public repositories was employed to identify clinically significant miRNAs involved in ovarian cancer. Targets of candidate miRNA were predicted using four online databases, and validated with dual luciferase assay. Loss and gain of function were performed to investigate the role of miR27a in the growth of ovarian cancer cell lines.

KEY FINDINGS

Based on cross-validation results in multiple datasets, we recognized hsa-miR-27a as an oncogenic molecular and a prognostic factor for ovarian cancer patients. Dual luciferase assay indicated tumor suppressor FOXO1 was a direct target of miR-27a. In addition, hsa-miR-27a could stimulate SKOV3 and A2780 cell proliferation and migration by regulating the expression of FOXO1.

SIGNIFICANCE

In summary, our results indicate that miR-27a can promote progression of ovarian cancer by mediating FOXO1. To our knowledge, this is the first study focusing on the role of miR-27a/FOXO1 axis using the microarray meta-analysis in ovarian cancer. Furthermore, inhibiting miR-27a expression may be a new strategy for the treatment of ovarian cancer.

Cholesterol promotes the migration and invasion of renal carcinoma cells by regulating the KLF5/miR-27a/FBXW7 pathway

Clear cell renal cell carcinoma (ccRCC) is the most common and lethal subtype of renal cell carcinoma. Accumulation of cholesterol and cholesterol ester is a remarkable feature of ccRCC. However, the effect of cholesterol on ccRCC remains unknown. Out results showed that cholesterol treatment significantly promoted cells migration and invasion in ccRCC. Mechanism analysis indicated that cholesterol induced KLF5 expression. KLF5 positively regulated the transcription of miR-27a, increasing miR-27a expression. MiR-27a directly targeted FBXW7 by binding to its 3'UTR, reducing FBXW7 expression. FBXW7 silencing further increased the expression of KLF5 and miR-27a, and promoted cells migration and invasion. These results suggested that cholesterol accelerated ccRCC cells migration and invasion by regulating KLF5/miR-27a/FBXW7 axis.