miR-202 inhibits the progression of human cervical cancer through inhibition of cyclin D1

Antitumor Effects of Curcumin on Cervical Cancer with the Focus on Molecular Mechanisms: An Exegesis

Cervical cancer is one of the most prevalent malignancies among females and is correlated with a significant fatality rate. Chemotherapy is the most common treatment for cervical cancer; however, it has a low success rate due to significant side effects and the incidence of chemo-resistance. Curcumin, a polyphenolic natural compound derived from turmeric, acts as an antioxidant by diffusing across cell membranes into the endoplasmic reticulum, mitochondria, and nucleus, where it performs its effects. As a result, it's been promoted as a chemo-preventive, anti-metastatic, and anti-angiogenic agent. As a consequence, the main goal of the present review was to gather research information that looked at the link between curcumin and its derivatives against cervical cancer.

A microRNA Prognostic Signature in Patients with Diffuse Intrinsic Pontine Gliomas through Non-Invasive Liquid Biopsy

Simple Summary

Diffuse intrinsic pontine glioma (DIPG) is a neuro-radiologically defined tumor of the brainstem, primarily affecting children, with most diagnoses occurring between 5 and 7 years of age. Surgical removal in DIPGs is not feasible. Subsequent tumor progression is almost universal and no biomarker for predicting the course of the disease has entered into clinical practice so far. Under these premises, it is essential to develop reliable biomarkers that are able to improve outcomes and stratify patients using non-invasive methods to determine tumor profiles. We designed a study assessing circulating miRNA expression by a high-throughput platform and divided patients into training and validation phases in order to disclose a potential signature with clinical impact. Our results for the first time have proved the usefulness of blood-circulating nucleic acids as powerful, easy-to-assay molecular markers of disease status in DIPG.

Abstract

Diffuse midline gliomas (DMGs) originate in the thalamus, brainstem, cerebellum and spine. This entity includes tumors that infiltrate the pons, called diffuse intrinsic pontine gliomas (DIPGs), with a rapid onset and devastating neurological symptoms. Since surgical removal in DIPGs is not feasible, the purpose of this study was to profile circulating miRNA expression in DIPG patients in an effort to identify a non-invasive prognostic signature with clinical impact. Using a high-throughput platform, miRNA expression was profiled in serum samples collected at the time of MRI diagnosis and prior to radiation and/or systemic therapy from 47 patients enrolled in clinical studies, combining nimotuzumab and vinorelbine with concomitant radiation. With progression-free survival as the primary endpoint, a semi-supervised learning approach was used to identify a signature that was also tested taking overall survival as the clinical endpoint. A signature comprising 13 circulating miRNAs was identified in the training set (n = 23) as being able to stratify patients by risk of disease progression (log-rank p = 0.00014; HR = 7.99, 95% CI 2.38–26.87). When challenged in a separate validation set (n = 24), it confirmed its ability to predict progression (log-rank p = 0.00026; HR = 5.51, 95% CI 2.03–14.9). The value of our signature was also confirmed when overall survival was considered (log-rank p = 0.0021, HR = 4.12, 95% CI 1.57–10.8). We have identified and validated a prognostic marker based on the expression of 13 circulating miRNAs that can shed light on a patient’s risk of progression. This is the first demonstration of the usefulness of nucleic acids circulating in the blood as powerful, easy-to-assay molecular markers of disease status in DIPG. This study provides Class II evidence that a signature based on 13 circulating miRNAs is associated with the risk of disease progression.

The microRNA-202 as a Diagnostic Biomarker and a Potential Tumor Suppressor

MicroRNA-202 (miR-202) is a member of the highly conserved let-7 family that was discovered in Caenorhabditis elegans and recently reported to be involved in cell differentiation and tumor biology. In humans, miR-202 was initially identified in the testis where it was suggested to play a role in spermatogenesis. Subsequent research showed that miR-202 is one of the micro-RNAs that are dysregulated in different types of cancer. During the last decade, a large number of investigations has fortified a role for miR-202 in cancer. However, its functions can be double-edged, depending on context they may be tumor suppressive or oncogenic. In this review, we highlight miR-202 as a potential diagnostic biomarker and as a suppressor of tumorigenesis and metastasis in several types of tumors. We link miR-202 expression levels in tumor types to its involved upstream and downstream signaling molecules and highlight its potential roles in carcinogenesis. Three well-known upstream long non-coding-RNAs (lncRNAs); MALAT1, NORAD, and NEAT1 target miR-202 and inhibit its tumor suppressive function thus fueling cancer progression. Studies on the downstream targets of miR-202 revealed PTEN, AKT, and various oncogenes such as metadherin (MTDH), MYCN, Forkhead box protein R2 (FOXR2) and Kirsten rat sarcoma virus (KRAS). Interestingly, an upregulated level of miR-202 was shown by most of the studies that estimated its expression level in blood or serum of cancer patients, especially in breast cancer. Reduced expression levels of miR-202 in tumor tissues were found to be associated with progression of different types of cancer. It seems likely that miR-202 is embedded in a complex regulatory network related to the nature and the sensitivity of the tumor type and therapeutic (pre)treatments. Its variable roles in tumorigenesis are mediated in part thought its oncogene effectors. However, the currently available data suggest that the involved signaling pathways determine the anti- or pro-tumorigenic outcomes of miR-202’s dysregulation and its value as a diagnostic biomarker.

Identification of cyclin D1 as a major modulator of 3-nitropropionic acid-induced striatal neurodegeneration

Mitochondria dysfunction occurs in the aging brain as well as in several neurodegenerative disorders and predisposes neuronal cells to enhanced sensitivity to neurotoxins. 3-nitropropionic acid (3-NP) is a naturally occurring plant and fungal neurotoxin that causes neurodegeneration predominantly in the striatum by irreversibly inhibiting the tricarboxylic acid respiratory chain enzyme, succinate dehydrogenase (SDH), the main constituent of the mitochondria respiratory chain complex II. Significantly, although 3-NP-induced inhibition of SDH occurs in all brain regions, neurodegeneration occurs primarily and almost exclusively in the striatum for reasons still not understood. In rodents, 3-NP-induced striatal neurodegeneration depends on the strain background suggesting that genetic differences among genotypes modulate toxicant variability and mechanisms that underlie 3-NP-induced neuronal cell death. Using the large BXD family of recombinant inbred (RI) strains we demonstrate that variants in Ccnd1 - the gene encoding cyclin D1 - of the DBA/2 J parent underlie the resistance to 3-NP-induced striatal neurodegeneration. In contrast, the Ccnd1 variant inherited from the widely used C57BL/6 J parental strain confers sensitivity. Given that cellular stress triggers induction of cyclin D1 expression followed by cell-cycle re-entry and consequent neuronal cell death, we sought to determine if the C57BL/6 J and DBA/2 J Ccnd1 variants are differentially modulated in response to 3-NP. We confirm that 3-NP induces cyclin D1 expression in striatal neuronal cells of C57BL/6 J, but this response is blunted in the DBA/2 J. We further show that striatal-specific alternative processing of a highly conserved 3'UTR negative regulatory region of Ccnd1 co-segregates with the C57BL/6 J parental Ccnd1 allele in BXD strains and that its differential processing accounts for sensitivity or resistance to 3-NP. Our results indicate that naturally occurring Ccnd1 variants may play a role in the variability observed in neurodegenerative disorders involving mitochondria complex II dysfunction and point to cyclin D1 as a possible therapeutic target.

HPV-16/18 E6-induced APOBEC3B expression associates with proliferation of cervical cancer cells and hypomethylation of Cyclin D1

Oncogenic high-risk human papillomavirus (HR-HPV) infection causes a majority of cases of cervical cancer and pre-cancerous cervical lesions. However, the mechanisms underlying the direct evolution from HPV-16/18-infected epithelium to cervical intraepithelial neoplasia (CIN) III, which can progress to cervical cancer, remain poorly identified. Here, we performed RNA-seq after laser capture microdissection, and found that APOBEC3B was highly expressed in cervical cancer specimens compared with CIN III with HPV-16/18 infection. Furthermore, immunohistochemical analysis confirmed that high levels of APOBEC3B were correlated with lymph node metastasis in cervical cancer. Subsequent experiments revealed that HPV-16 E6 could upregulate APOBEC3B through direct binding to the promoter of APOBEC3B in cervical cancer cells. Silencing of APOBEC3B by stable short hairpin RNA-mediated knockdown reduced the proliferative capacity of Caski and HeLa cells in vitro and in vivo, but had only a small effect on the migration and invasion of two cervical cancer cell lines. Finally, we identified the changes in gene expression following APOBEC3B silencing in Caski cells by microarray, demonstrating a biological link between APOBEC3B and CCND1 in cervical cancer cells. Importantly, through methyl-capture sequencing and pyrosequencing, APOBEC3B was found to affect the levels of the downstream protein Cyclin D1 (which is encoded by the CCND1 gene) through hypomethylation of the CCND1 promoter. In conclusion, our study supports HPV-16 E6-induced APOBEC3B expression associates with proliferation of cervical cancer cells and hypomethylation of Cyclin D1. Thus, APOBEC3B may be a potential therapeutic target in human cervical cancer.

MicroRNA-202 suppresses glycolysis of pancreatic cancer by targeting hexokinase 2

Purpose: Various studies have identified miR-202 critically participated in the development of different cancers. However, the potential mechanisms underlying the carcinogenesis of pancreatic cancer (PC) still remains elusive. Methods: In the study, cell proliferation assay, colony formation assay, EdU incorporation assay, Luciferase reporter assay, lactate production, glucose consumption assay, real-time PCR and western blot were used to investigate the mechanism of hexokinase 2 (HK2) regulated by miR-202 in pancreatic cancer in vitro and in vivo. Results: Here we found that miR-202 was decreased in the PC tissues, and its low expression was correlated with a poor prognosis of PC patients. Overexpression of miR-202 in PC cells reduced cell proliferation and tumorigenesis by impairing glycolysis, while downregulation of miR-202 promoted the cells proliferative capacity. Mechanically, we demonstrated that HK2, an enzyme that catalyzes the irreversible rate-limiting step of glycolysis, as the direct target of miR-202. Overexpression of miR-202 suppressed both the mRNA and protein levels of HK2, whereas re-introduction of HK2 abrogated miR-202-mediated glycolytic inhibition. In addition, the expression of miR-202 was negatively associated with HK2 level in a cohort of PC tissues. Conclusion: Our findings validate the mechanism that miR-202 reprograms the metabolic process to promote PC progression, thus providing potential prognostic predictors for PC patients.

MicroRNA-202 inhibits cell migration and invasion through targeting FGF2 and inactivating Wnt/β-catenin signaling in endometrial carcinoma

Recently, many mircroRNAs (miRNAs) involved in the development and progression of cancer have been reported to regulate cell growth and metastasis, including microRNA-202 (miR-202). The purpose of the present study was to elucidate the effect of miR-202 on endometrial carcinoma (EC) cell migration and invasion. First, qRT-PCR showed that miR-202 was down-regulated in EC tissues, which was associated with poor prognosis in EC patients. Functionally, transwell assay indicated that miR-202 inhibited cell migration and invasion in EC cells. In addition, miR-202 also blocked epithelial-mesenchymal transition (EMT) through suppressing N-cadherin and Vimentin expressions and promoting E-cadherin expression. Moreover, the dual-luciferase reporter assay showed that fibroblast growth factor 2 (FGF2) is a direct target gene for miR-202 in EC cells. Furthermore, up-regulation of FGF2 attenuated the inhibitory effect of miR-202 on cell migration and invasion in EC. Besides that, miR-202 inactivated the Wnt/β-catenin signaling by suppressing β-catenin expression in EC. In conclusion, miR-202 inhibited cell migration and invasion by targeting FGF2 and inactivating the Wnt/β-catenin signaling in EC.

The roles of microRNA in human cervical cancer

Although a potentially preventable disease, cervical cancer (CC) is the second most commonly diagnosed gynaecological cancer with at least 530,000 new cases annually, and the prognosis with CC is still poor. Studies suggest that aberrant expression of microRNA (miRNA) contributes to the progression of CC. As a group of small non-coding RNA with 18-25 nucleotides, miRNA regulate about one-third of all human genes. They function by repressing translation or inducing mRNA cleavage or degradation, including genes involved in diverse and important cellular processes, including cell cycling, proliferation, differentiation, and apoptosis. Results showed that misexpression of miRNA is closely related to the onset and progression of CC. This review will provide an overview of the function of miRNA in CC and the mechanisms involved in cervical carcinogenesis.

miR-202 Suppresses Hepatocellular Carcinoma Progression via Downregulating BCL2 Expression

miRNAs play an important role in progression of hepatocellular carcinoma (HCC). In this work, we assessed the function of miR-202 in human HCC and identified BCL2 as its target. We found miR-202 expression was found significantly downregulated, while BCL2 expression was markedly upregulated in HCC tissues and cell lines (HepG2, Hep3B, and HCCLM3). Both miR-202 and BCL2 were closely correlated with major vascular invasion and advanced TNM stage as well as overall survival of HCC patients. Overexpression of miR-202 significantly inhibited cell proliferation, induced apoptosis and cell cycle arrest at the G₀/G₁ phase, and prevented tumor formation in a xenograft nude mouse model. Further, miR-202 dramatically inhibited migration, invasion, and epithelial–mesenchymal transition. miR-202 bound to the 3′-untranslated region (3′-UTR) of BCL2 mRNA and downregulated the expression level of BCL2 protein. Exogenous BCL2 overexpression weakened the inhibitory effects of miR-202, while inhibition of BCL2 enhanced the inhibitory effects of miR-202. In conclusion, miR-202 serves as a tumor suppressor in HCC progression by downregulating BCL2 expression, indicating miR-202 might be a potential target for HCC.

miR-202 functions as a tumor suppressor in hepatocellular carcinoma by targeting HK2

Recent evidence has suggested that microRNAs (miRNAs) can participate in metabolic reprogramming. Additionally, aerobic glycolysis is associated with tumor progression in hepatocellular carcinoma (HCC). In the present study, miRNA (miR)-202 expression levels were found to be significantly lower in HCC tissues compared with the corresponding adjacent non-cancerous tissue samples using reverse transcription-quantitative PCR analysis in 56 patients with HCC. Lower miR-202 expression levels were identified to be associated with tumor size, vascular invasion, Tumor, Node and Metastasis stages and poor overall survival rates in patients with HCC. In vitro, upregulation of miR-202 expression was revealed to significantly suppress the cell glucose uptake, lactate production and cell proliferation in liver cancer cells. In addition, dual luciferase reporter analysis and western blot assays suggested that hexokinase 2 (HK2) was a direct target of miR-202. Upregulation of miR-202 expression could inhibit cell proliferation by regulating HK2 expression in HCC. Therefore, the results from the present study suggested that miR-202 may serve as a potential target for HCC treatment.

Long non-coding RNA HOX transcript antisense RNA (HOTAIR) suppresses the angiogenesis of human placentation by inhibiting vascular endothelial growth factor A expression

HOX transcript antisense RNA (HOTAIR) is a long non-coding RNA located within the Homeobox C (HOXC) gene cluster on chromosome 12. Previous studies have revealed that HOTAIR is overexpressed in many types of cancers and is associated with metastasis and poor survival rates; however, few reports have mentioned the relationship between HOTAIR and angiogenesis of the human placenta. The aim of the present study was to investigate the correlation between HOTAIR and vascular endothelial growth factor (VEGF) A in the human placenta. HOTAIR levels decreased significantly in human placenta with increasing gestational age, and were negatively correlated with VEGFA levels. Invitro assays revealed that HOTAIR overexpression suppressed the proliferation, migration, invasion and tube formation of human umbilical vein endothelial cells (HUVECs); however, inhibition of HOTAIR had the opposite effects. Furthermore, VEGFA overexpression reversed the inhibitory effect of HOTAIR on the proliferation, migration, invasion and tube formation of HUVECs. In addition, overexpression of HOTAIR significantly inhibited VEGFA expression. Notably, a luciferase reporter assay found that HOTAIR inhibited VEGFA transcription by directly targeting the VEGFA promoter. Together, these results suggest that HOTAIR plays an important role in suppressing angiogenesis of the human placenta by inhibiting the expression of VEGFA; thus, HOTAIR may represent a potential therapeutic target for patients with human placental vascularisation abnormalities.

Expression Of Cyclin D1 Protein Isoforms And Its Prognostic Significance In Cervical Cancer

Introduction

Cyclin D1 had been associated with different clinical and pathological stages of cervical cancer; however, few studies had focused on its correlation with cervical cancer prognosis. Therefore, this study aimed to assess the expression of cyclin D1a and D1b in normal tissue, cervical cancer and cervical intraepithelial neoplasia and their effect on prognosis.

Methods

Expression of cyclin D1a and D1b was detected by immunohistochemical staining in 78 cases of primary cervical cancer, 40 cases of cervical intraepithelial neoplasia, and 40 cases of normal cervical tissue.

Results

No significant difference was observed in the expression of cyclin D1a between normal and cervical cancer tissues (P = 0.201); however, its expression was significantly higher in cervical cancer than in cervical intraepithelial neoplasia tissues (P = 0.000). Expression of cyclin D1b was higher in normal tissues than in cervical cancer tissues (P = 0.000). No significant difference was observed in the expression of cyclin D1a in cervical cancer tissues with respect to age, pathological type, clinical-stage, depth of tumor invasion, or presence of lymph node metastases (P = 0.111,0.119,0.539,0.084,0.539). COX survival analysis showed that lymph node metastasis might be an independent factor affecting postoperative recurrence (hazard risk [HR] = 0.240; 95% confidence interval [CI] = 0.968–30.156; P = 0.034).

Discussion

Cyclin D1a expression was associated with tumor tissue size and degree of differentiation. The expression of cyclin D1b in cervical cancer was associated with the presence of lymph node metastases. Cyclin D1a and D1b expression in cervical cancer tissue was significantly correlated. Cox survival analysis showed that the presence of lymph node metastases might serve as an independent factor affecting postoperative recurrence. The expression of cyclin D1a and D1b was not associated with cervical cancer prognosis.

Conclusion

Assessment of cyclin D1a and D1b expression in cervical cancer and cervical intraepithelial neoplasia revealed that cyclin D1 could not be used as a reference to assess cervical cancer patient prognosis.

Identification and performance evaluation of housekeeping genes for microRNA expression normalization by reverse transcription-quantitative PCR using liquid-based cervical cytology samples

Screening for cervical cancer by cytology has been effective in reducing the worldwide incidence and mortality rates of this disease. However, a number of studies have demonstrated that the sensitivity of conventional cervical cytology may be too low for detection of cervical intraepithelial neoplasias (CIN). Therefore, it is important to incorporate more sensitive molecular diagnostic tests that could substantially improve the detection rates and accuracy for identifying CIN lesions. MicroRNAs (miRNAs) are a class of small non-coding RNAs with the potential to provide robust non-invasive cancer biomarkers for detecting CIN lesions in liquid-based cervical cytology (LBC) samples. At present, there is no consensus on which are the best housekeeping genes for miRNA normalization in LBC. The present study aimed to identify housekeeping genes with consistent and reproducible performance for normalization of reverse transcription-quantitative PCR (RT-qPCR) expression analysis of miRNA using LBC samples. The present study firstly selected six potential candidate housekeeping genes based on a systematic literature evaluation. Subsequently, the expression levels of microRNAs U6, RNU-44, RNU-47, RNU-48, RNU-49 and hsa-miR-16 were measured in 40 LBC samples using RT-qPCR. The stability of each potential housekeeping gene was assessed using the NormFinder algorithm. The results revealed that U6 and RNU-49 were the most stable genes among all candidates requiring fewer amplification cycles and smaller variation across the sample set. However, RNU-44, RNU-47, RNU-48 and hsa-miR-16 stability exceeded the recommended housekeeping value suitable for normalization. The findings revealed that U6 may be a reliable housekeeping gene for normalization of miRNA RT-qPCR expression analysis using LBC samples.

NK cell and macrophages confer prognosis and reflect immune status in osteosarcoma

Osteosarcoma (OS) is a common primary malignant bone tumor in young adolescents. About 30% of patients with OS have a recurrence, and the overall survival after OS recurrence is not good. In this study, we aimed to analyze and identify factors that influence prognosis after OS relapse. We retrieved the Gene Expression Omnibus data set and collected a series of transcriptome data with clinical information, including microRNA (miRNA) and messenger RNA (mRNA) expression profiles in recurrent OS. Upon comparison of the dysregulated genes of survival status in the recurrent OS samples, it was found that there were 268 differential expressed (DE) mRNAs and six DE miRNAs. These genes are related to pathways in cancer. We also predicted the interaction networks of these DE mRNAs and miRNAs. Further, we applied cibersort to estimate the proportion of immune cell types and we discovered that natural killer cells and macrophages have different abundance between good prognosis and poor prognosis. Our study indicates that for recurrent OS samples, there are several differences between these two groups, including gene expression and the status of immune activation. The immunity status is a candidate signature for disease prediction, prevention, and therapy choices.

CORO1C expression is associated with poor survival rates in gastric cancer and promotes metastasis in vitro

Coronin-like actin-binding protein 1C (CORO1C) is a member of the WD repeat protein family that regulates actin-dependent processes by assembling F-actin. CORO1C was previously reported to promote metastasis in breast cancer and lung squamous cell carcinoma. Here, we investigated the role of CORO1C in gastric cancer. Higher expression levels of CORO1C were detected in gastric cancer tissues as compared with normal gastric tissues. In addition, CORO1C levels were found to be positively correlated with lymph node metastasis in gastric cancer patients. The expression levels of CORO1C were higher in stage III-IV gastric cancer patients (80.8%) than in stage I-II gastric cancer patients(57.1%). Gastric cancer patients positive for CORO1C expression showed lower relapse-free survival and overall survival rates. Knockdown of CORO1C dramatically suppressed total cell number, cell viability, cell colony formation, cell mitosis and cell metastasis, and promoted apoptosis of gastric cancer cells. Furthermore, cyclin D1 and vimentin were found to be positively regulated by CORO1C. As cyclin D1 and vimentin play an oncogenic role in gastric cancer, CORO1C may exert its tumor-promoting activity through these proteins.

microRNAs: New prognostic, diagnostic, and therapeutic biomarkers in cervical cancer

Cervical cancer is as a kind of cancer beginning from the cervix. Given that cervical cancer could be observed in women who infected with papillomavirus, regular oral contraceptives, and multiple pregnancies. Early detection of cervical cancer is one of the most important aspects of the therapy of this malignancy. Despite several efforts, finding and developing new biomarkers for cervical cancer diagnosis are required. Among various prognostic, diagnostic, and therapeutic biomarkers, miRNA have been emerged as powerful biomarkers for detection, treatment, and monitoring of response to therapy in cervical cancer. Here, we summarized various miRNAs as an employable platform for prognostic, diagnostic, and therapeutic biomarkers in the treatment of cervical cancer.

Identification of Key Genes and Pathways in Cervical Cancer by Bioinformatics Analysis

Cervical cancer is a common malignant tumour of the female reproductive system that seriously threatens the health of women. The aims of this study were to identify key genes and pathways and to illuminate new molecular mechanisms underlying cervical cancer. Altogether, 1829 DEGs were identified, including 794 significantly down-regulated DEGs and 1035 significantly up-regulated DEGs. GO analysis suggested that the up-regulated DEGs were mainly enriched in mitotic cell cycle processes, including DNA replication, organelle fission, chromosome segregation and cell cycle phase transition, and that the down-regulated DEGs were primarily enriched in development and differentiation processes, such as tissue development, epidermis development, skin development, keratinocyte differentiation, epidermal cell differentiation and epithelial cell differentiation. KEGG pathway analysis showed that the DEGs were significantly enriched in cell cycle, DNA replication, the p53 signalling pathway, pathways in cancer and oocyte meiosis. The top 9 hub genes with a high degree of connectivity (over 72 in the PPI network) were down-regulated TSPO, CCND1, and FOS and up-regulated CDK1, TOP2A, CCNB1, PCNA, BIRC5 and MAD2L1. Module analysis indicated that the top 3 modules were significantly enriched in mitotic cell cycle, DNA replication and regulation of cell cycle (P < 0.01). The heat map based on TCGA database preliminarily demonstrated the expression change of the key genes in cervical cancer. GSEA results were basically coincident with the front enrichment analysis results. By comprehensive analysis, we confirmed that cell cycle was a key biological process and a critical driver in cervical cancer. In conclusion, this study identified DEGs and screened the key genes and pathways closely related to cervical cancer by bioinformatics analysis, simultaneously deepening our understanding of the molecular mechanisms underlying the occurrence and progression of cervical cancer. These results might hold promise for finding potential therapeutic targets of cervical cancer.

miR-202-3p Regulates Sertoli Cell Proliferation, Synthesis Function, and Apoptosis by Targeting LRP6 and Cyclin D1 of Wnt/β-Catenin Signaling

MicroRNAs (miRNAs) play important roles in mammalian spermatogenesis, which is highly dependent on Sertoli cells. However, the functions and mechanisms of miRNAs in regulating human Sertoli cells remain largely unknown. Here, we report that hsa-miR-202-3p mediates the proliferation, apoptosis, and synthesis function of human Sertoli cells. miR-202-3p was upregulated in Sertoli cells of Sertoli cell-only syndrome (SCOS) patients compared with obstructive azoospermia (OA) patients with normal spermatogenesis. Overexpression of miR-202-3p induced Sertoli cell apoptosis and inhibited cell proliferation and synthesis, and the effects were opposite when miR-202-3p was knocked down. Lipoprotein receptor-related protein 6 (LRP6) and Cyclin D1 of the Wnt/β-catenin signaling pathway were identified as direct targets of miR-202-3p in Sertoli cells, which were validated by bioinformatics tools and dual-luciferase reporter assay. Differentially expressed LRP6 and Cyclin D1 between OA and SCOS Sertoli cells were also verified. LRP6 small interfering RNA (siRNA) interference not only mimicked the effects of miR-202-3p overexpression, but also antagonized the effects of miR-202-3p inhibition on Sertoli cells. Collectively, miR-202-3p controls the proliferation, apoptosis, and synthesis function of human Sertoli cells via targeting LRP6 and Cyclin D1 of the Wnt/β-catenin signaling pathway. This study thus provides a novel insight into fate determinations of human Sertoli cells and niche of human testis.

MicroRNA-217 functions as a tumor suppressor in cervical cancer cells through targeting Rho-associated protein kinase 1

The abnormal expression of microRNAs (miRNAs/miRs) has been widely reported in various tumor types. miR-217 was demonstrated to be aberrantly expressed in a number of tumors, including pancreatic adenocarcinoma and osteosarcoma; however, its specific expression pattern has never been investigated in cervical cancer cells. Compared with normal control, the level of Rho-associated protein kinase 1 (ROCK1) expression was markedly increased in cervical cancer tissues and cells compared with that in non-cancerous tissues and cells. The expression of miR-217 was significantly reduced in cervical cancer tissues and cell lines. Overexpression of miR-217 could suppress colony formation and the cell invasion capacity of SiHa and HeLa cells. Flow cytometry indicated that miR-217 significantly increased cell apoptosis in SiHa and HeLa cells. Dual-luciferase reporter assays demonstrated that ROCK1 was a target gene of miR-217. In addition, overexpression of ROCK1 also led to an increased invasion capacity in SiHa cells, even when miR-217 was inhibited, indicating that the anti-invasive effects of miR-217 were mediated through ROCK1. In summary, the results of the present study indicated that miR-217 functions as a tumor suppressor in cervical cancer cells, primarily by targeting ROCK1.

miR-202 acts as a potential tumor suppressor in breast cancer

Breast cancer affects ~10% of women worldwide and is responsible for ~12% of all cancer-associated mortalities. Breast cancer is more prone to metastasis compared with other types of cancer. Up to 5% of patients with breast cancer present with incurable metastasis and an additional 10-15% of patients develop metastases within 3 years of their initial diagnosis. MicroRNAs (miRNAs) are short RNAs, 21-25 nucleotides in length, that have been shown to significantly affect gene expression. In total >2,000 miRNAs have been identified and specific miRNAs have been revealed to be associated with cancer. In the present study, we observed that the majority of breast cancer specimens collected expressed low levels of miR-202 compared with adjacent tissues and normal cell lines. Mechanistic investigations identified KRAS as a potential target gene of miR-202 and it was demonstrated that miR-202 exerted its tumor-suppressive effects by regulating the expression of KRAS in breast cancer cells. Functional assays revealed that miR-202 significantly reduced cell proliferation, migration and invasion in vitro. In summary, these results indicate the function of miR-202 in breast cancer progression and suggest that its use within breast cancer therapy is promising.

Overexpression of miR-202 resensitizes imatinib resistant chronic myeloid leukemia cells through targetting Hexokinase 2

Chronic myeloid leukemia (CML) is a myeloproliferative disease which uniquely expresses a constitutively active tyrosine kinase, BCR/ABL. As a specific inhibitor of the BCR-ABL tyrosine kinase, imatinib becomes the first choice for the treatment of CML due to its high efficacy and low toxicity. However, the development of imatinib resistance limits the long-term treatment benefits of it in CML patients. In the present study, we aimed to investigate the roles of miR-202 in the regulation of imatinib sensitivity in CML cell lines and the possible mechanisms involved in this process. We found miR-202 was down-regulated in seven CML cell lines by quantitative reverse-transcription PCR (qRT-PCR) analysis. Overexpression of miR-202 significantly suppressed proliferation rates of CML cells. By establishing imatinib resistant cell lines originating from K562 and KU812 cells, we observed expressions of miR-202 were down-regulated by imatinib treatments and imatinib resistant CML cell lines exhibited lower level of miR-202. On the contrary, imatinib resistant CML cell lines displayed up-regulated glycolysis rate than sensitive cells with the evidence that glucose uptake, lactate production, and key glycolysis enzymes were elevated in imatinib resistant cells. Importantly, the imatinib resistant CML cell lines were more sensitive to glucose starvation and glycolysis inhibitors. In addition, we identified Hexokinase 2 (HK2) as a direct target of miR-202 in CML cell lines. Overexpression of miR-202 sensitized imatinib resistant CML through the miR-202-mediated glycolysis inhibition by targetting HK2. Finally, we provided the clinical relevance that miR-202 was down-regulated in CML patients and patients with lower miR-202 expression displayed higher HK2 expression. The present study will provide new aspects on the miRNA-modulated tyrosine kinase inhibitor (TKI) sensitivity in CML, contributing to the development of new therapeutic anticancer drugs.

MicroRNA-30e Functions as a Tumor Suppressor in Cervical Carcinoma Cells through Targeting GALNT7

Cervical cancer is the third most common cancer in women worldwide. However, the underlying mechanism of occurrence and development of cervical cancer is obscure. In this study, we observed that miR-30e was downregulated in clinical cervical cancer tissues and cervical cancer cells. Next, overexpression of miR-30e reduced the cervical cancer cell growth through MTT, colony formation, EdU, and Transwell assay in SiHa and Caski cells. Subsequently, UDP-N-acetyl-D-galactosamine: polypeptide N-acetylgalactosaminyltransferase 7 (GALNT7) was identified as a potential miR-30e target by bioinformatics analysis. Moreover, we showed that miR-30e was able to bind to the 3′UTR of GALNT7 by luciferase reporter assay. In addition, the mRNA and protein levels of GALNT7 in cervical cancer cells were downregulated by miR-30e. And we validated that downregulation of GALNT7 repressed the proliferation of SiHa and Caski cells by MTT, colony formation, and Transwell assay. We identified that the restoration of GALNT7 expression was able to counteract the effect of miR-30e on cell proliferation of cervical cancer cells. Furthermore, we found that the expression levels of GALNT7 were frequently upregulated and negatively correlative to those of miR-30e in cervical cancer tissues. In addition, we validated that restoration of GALNT7 rescued the miR-30e–suppressed growth of cervical cancer xenografts in vivo. In conclusion, the current results suggest that miR-30e may function as tumor suppressors in cervical cancer through downregulation of GALNT7. Both miR-30e and its novel target, GALNT7, may play an important role in the process of cervical cancer.

miR-202 Suppresses Cell Proliferation by Targeting FOXR2 in Endometrial Adenocarcinoma

Background

MicroRNA-202 (miR-202) has been reported to be aberrantly regulated in several cancers. The aim of this study is to explore the functional role of miR-202 in EAC tumor growth.

Material and Methods

miR-202 expression was detected by qRT-PCR. TargetScan and luciferase reporter assay were used to elucidate the candidate target gene of miR-202. The FOXR2 protein level was assessed by Western blot and immunohistochemistry. Survival analysis was explored for FOXR2 expression in EAC patients.

Results

miR-202 expression was significantly decreased in EAC tissues (P < 0.01) compared with that in control tissues. And the downregulate miR-202 was significantly associated with poor prognosis (P < 0.01). Re-expression of miR-202 dramatically suppressed cell proliferation in vitro and tumor growth in vivo. FOXR2 was identified as a direct target of miR-202. In EAC tissues, FOXR2 was upregulated and the increased FOXR2 was significantly associated with poor prognosis. In miR-202-transfected cells, the FOXR2 expression was inversely changed. The analysis of FOXR2 protein expression and miR-202 transcription in EAC tissues showed negative correlation (R = −0.429).

Conclusion

miR-202 may function as a tumor suppressor in EAC tumor growth by targeting FOXR2 oncogene, which may provide new insights into the molecular mechanism and new targets for treatment of EAC.

MicroRNA-202 inhibits cell proliferation, migration and invasion of glioma by directly targeting metadherin

Glioma is the most common and aggressive type of primary malignant brain tumour. Increasing evidence has revealed that microRNAs play important roles in multiple biological processes related to glioma occurrence, development, diagnosis, treatment and prognosis. MicroRNA-202 (miR-202) has been studied in several types of human cancer, whereas the biological roles of miR-202 in glioma remain unknown. The present study, aimed to investigate the expression, clinical significance and biological roles of miR-202 in glioma, as well as its underlying molecular mechanism. We found that miR-202 was significantly downregulated in glioma tissues and cell lines. Low miR-202 expression was associated with Karnofsky performance status (KPS) score and World Health Organization (WHO) grade of glioma patients. Functional assays revealed that ectopic expression of miR-202 inhibited cell proliferation, migration and invasion of glioma. In addition, metadherin (MTDH) was identified as a direct target gene of miR-202 in glioma through bioinformatic analysis, luciferase reporter assay, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting. Furthermore, MTDH expression was upregulated and negatively correlated with miR-202 expression in clinical glioma tissues. MTDH knockdown had similar roles to miR-202 overexpression in glioma cells. Rescue experiments revealed that upregulation of MTDH reversed the suppression of glioma cell growth and metastasis by miR-202. Moreover, miR-202 impaired the PI3K/Akt and Wnt/β-catenin pathways. These results highlight the tumour-suppressive effect of miR-202 in glioma, thereby suggesting that miR-202 may be a potential therapeutic target for the treatment of patients with this malignancy.