MiR-96 downregulates RECK to promote growth and motility of non-small cell lung cancer cells

MiR-21 Regulates Growth and Migration of Cervical Cancer Cells by RECK Signaling Pathway

Expression of miR-21 has been found to be altered in almost all types of cancers, and it has been classified as an oncogenic microRNA. In addition, the expression of tumor suppressor gene RECK is associated with miR-21 overexpression in high-grade cervical lesions. In the present study, we analyze the role of miR-21 in RECK gene regulation in cervical cancer cells. To identify the downstream cellular target genes of upstream miR-21, we silenced endogenous miR-21 expression using siRNAs. We analyzed the expression of miR-21 and RECK, as well as functional effects on cell proliferation and migration. We found that in cervical cancer cells, there was an inverse correlation between miR-21 expression and RECK mRNA and protein expression. SiRNAs to miR-21 increased luciferase reporter activity in construct plasmids containing the RECK-3'-UTR microRNA response elements MRE21-1, MRE21-2, and MRE21-3. The role of miR-21 in cell proliferation was also analyzed, and cancer cells transfected with siRNAs exhibited a markedly reduced cell proliferation and migration. Our findings indicate that miR-21 post-transcriptionally down-regulates the expression of RECK to promote cell proliferation and cell migration inhibition in cervical cancer cell survival. Therefore, miR-21 and RECK may be potential therapeutic targets in gene therapy for cervical cancer.

LIM-domain binding protein 2 was down-regulated by miRNA-96-5p inhibited the proliferation, invasion and metastasis of lung cancer H1299 cells

OBJECTIVES

Lung cancer was one of the most common malignancies around the world. It has great significance in to search for the mechanism of occurrence and development of lung cancer. LIM Domain Binding protein 2 (LDB2) belongs to the LIM-domain binding family, it can be used as a binding protein that combined with other transcription factors to form the transcription complex for regulating the expression of target genes. The expression of microRNA-96-5p (miR-96-5p) has been investigated in various tumors. The aim of this study is to investigate the potential role of LDB2 and miR-96-5p in lung cancer.

METHODS

Real-time quantitative PCR was applied to detect the expression of LDB2 and miR-96-5p. The proliferation, invasion, and metastasis of H1299 cells were analyzed by CCK8, transwell, and wound healing assay after LDB2 or miR-96-5p transfection. Luciferase activities assay and western blot were used to reveal the targeted regulation between LDB2 and miR-96-5p.

RESULTS

Here the authors found LDB2 was down-regulated in lung cancer tissues and negatively correlated with miR-96-5p expression, it could promote or inhibit the proliferation, invasion and metastasis of H1299 cells after LDB2 knockdown or overexpression and regulate the expression of cyclinD1, MMP9, Bcl-2, and Bax via ERK1/2 signaling pathway. Furthermore, miR-96-5p exerted its function by directly binding to 3'-UTR of LDB2 and regulating expression of LDB2. miR-96-5p could promote the proliferation, invasion, and metastasis of H1299 cells.

CONCLUSION

These findings demonstrate that LDB2 can act as a new regulator to inhibit cell proliferation, invasion, and metastasis via the ERK1/2 signaling pathway, and miR-96-5p may be a potential promising molecular by targeting LDB2 in lung cancer.

Identification of the Key miRNAs and Genes Associated with the Regulation of Non-Small Cell Lung Cancer: A Network-Based Approach

Lung cancer is the major cause of cancer-associated deaths across the world in both men and women. Lung cancer consists of two major clinicopathological categories, i.e., small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Lack of diagnosis of NSCLC at an early stage in addition to poor prognosis results in ineffective treatment, thus, biomarkers for appropriate diagnosis and exact prognosis of NSCLC need urgent attention. The proposed study aimed to reveal essential microRNAs (miRNAs) involved in the carcinogenesis of NSCLC that probably could act as potential biomarkers. The NSCLC-associated expression datasets revealed 12 differentially expressed miRNAs (DEMs). MiRNA-mRNA network identified key miRNAs and their associated genes, for which functional enrichment analysis was applied. Further, survival and validation analysis for key genes was performed and consequently transcription factors (TFs) were predicted. We obtained twelve miRNAs as common DEMs after assessment of all datasets. Further, four key miRNAs and nine key genes were extracted from significant modules based on the centrality approach. The key genes and miRNAs reported in our study might provide some information for potential biomarkers profitable to increased prognosis and diagnosis of lung cancer.

LncRNA HOXC-AS3 increases non-small cell lung cancer cell migration and invasion by sponging premature miR-96

BACKGROUND

HOXC cluster antisense RNA 3 (HOXC-AS3) has been characterized as a critical long noncoding RNA (lncRNA) player in breast cancer and gastric cancer, while its role in non-small cell lung cancer (NSCLC) is not clear. We hypothesized that HOXC-AS3 could interact with premature microRNA (miR)-96. This study was therefore carried out to explore the crosstalk between HOXC-AS3 and miR-96 in NSCLC.

METHODS

The expression of HOXC-AS3 and miR-96 (both mature and premature) were detected using RT-qPCR. Nuclear fractionation assay and RNA pull-down assay were performed to detect the subcellular location of HOXC-AS3 and potential interaction with premature miR-96, respectively. Overexpression assays were performed to determine the role of HOXC-AS3 in the maturation of miR-96. Transwell assays were performed to explore the role of HOXC-AS3 and miR-96 in NSCLC cell invasion and migration.

RESULTS

NSCLC tissues exhibited significantly increased expression levels of HOXC-AS3 and premature miR-96. HOXC-AS3 was localized to both nucleus and cytoplasm, and a direct interaction between HOXC-AS3 and premature miR-96 was observed. In NSCLC cells, HOXC-AS3 upregulated the expression of premature miR-96 but downregulated the expression of mature miR-96. Moreover, HOXC-AS3 suppressed the role of miR-96 in inhibiting NSCLC cell invasion and migration.

CONCLUSION

HOXC-AS3 may increase NSCLC cell growth and invasion by sponging premature miR-96 to suppress its maturation.

Identification of microRNA-96-5p as a postoperative, prognostic microRNA predictor in nonviral hepatocellular carcinoma

AIM

The microRNA (miR) clusters miR-183/96/182 and miR-217/216a/216b are significantly upregulated in nonviral hepatocellular carcinoma (NBNC-HCC). Here, we investigate the impact of each member of these clusters on the clinical outcome of NBNC-HCC and analyze the antitumor effects of miR-96-5p.

METHODS

The association between recurrence-free survival of 111 NBNC-HCC patients and the levels of miR-183-5p, miR-96-5p, miR-182-5p, miR-217-5p, miR-216a-5p, and miR-216b-5p in tumor and adjacent tissues was investigated. The impact of miR-96-5p on apoptosis and invasion of a hepatoma cell line, HepG2, was investigated by cell counting, Transwell assay, and flow cytometry, respectively.

RESULTS

MicroRNA-183-5p, miR-96-5p, miR-182-5p, miR-217-5p, and miR-216b-5p were significantly upregulated in tumor tissues compared to the adjacent tissues (p = 0.0005, p = 0.0030, p = 0.0002, p = 0.0011, and p = 0.0288, respectively). By multivariate Cox regression analysis, high tumor/adjacent ratios of miR-182-5p (p = 0.007) and miR-217-5p (p = 0.008) were associated with poor recurrence-free survival. In contrast, a low tumor/adjacent ratio of miR-96-5p (p < 0.001) was associated with poor recurrence-free survival. It suggested that further upregulation of miR-96-5p in tumors might have an inhibitory effect on recurrence. Transfection of miR-96-5p mimic significantly induced apoptosis of HepG2 cells, in association with downregulation of Nucleophosmin 1 (NPM1) and a decrease of phosphorylated AKT protein. Interestingly, simultaneous knockdown of the NPM1 and AKT genes induced apoptosis. MicroRNA-96-5p also suppressed proliferation and invasion, which inhibited epithelial-to-mesenchymal transition of HCC cells.

CONCLUSION

MicroRNA-96-5p as a tumor suppressor would be valuable to stratify NBNC-HCC patients at high risk of recurrence.

MicroRNA-96: A therapeutic and diagnostic tumor marker

Cancer has been always considered as one of the main human health challenges worldwide. One of the main causes of cancer-related mortality is late diagnosis in the advanced stages of the disease, which reduces the therapeutic efficiency. Therefore, novel non-invasive diagnostic methods are required for the early detection of tumors and improving the quality of life and survival in cancer patients. MicroRNAs (miRNAs) have pivotal roles in various cellular processes such as cell proliferation, motility, and neoplastic transformation. Since circulating miRNAs have high stability in body fluids, they can be suggested as efficient noninvasive tumor markers. MiR-96 belongs to the miR-183-96-182 cluster that regulates cell migration and tumor progression as an oncogene or tumor suppressor by targeting various genes in solid tumors. In the present review, we have summarized all of the studies that assessed the role of miR-96 during tumor progression. This review clarifies the molecular mechanisms and target genes recruited by miR-96 to regulate tumor progression and metastasis. It was observed that miR-96 mainly affects tumorigenesis by targeting the structural proteins and FOXO transcription factors.

MicroRNAs as a Suitable Biomarker to Detect the Effects of Long-Term Exposures to Nanomaterials. Studies on TiO2NP and MWCNT

The presence of nanomaterials (NMs) in the environment may represent a serious risk to human health, especially in a scenario of chronic exposure. To evaluate the potential relationship between NM-induced epigenetic alterations and carcinogenesis, the present study analyzed a panel of 33 miRNAs related to the cell transformation process in BEAS-2B cells transformed by TiO₂NP and long-term MWCNT exposure. Our battery revealed a large impact on miRNA expression profiling in cells exposed to both NMs. From this analysis, a small set of five miRNAs (miR-23a, miR-25, miR-96, miR-210, and miR-502) were identified as informative biomarkers of the transforming effects induced by NM exposures. The usefulness of this reduced miRNA battery was further validated in other previously generated transformed cell systems by long-term exposure to other NMs (CoNP, ZnONP, MSiNP, and CeO₂NP). Interestingly, the five selected miRNAs were consistently overexpressed in all cell lines and NMs tested. These results confirm the suitability of the proposed set of mRNAs to identify the potential transforming ability of NMs. Particular attention should be paid to the epigenome and especially to miRNAs for hazard assessment of NMs, as wells as for the study of the underlying mechanisms of action.

The role of non-coding RNAs in chemotherapy for gastrointestinal cancers

Gastrointestinal (GI) cancers, including colorectal, gastric, hepatic, esophageal, and pancreatic tumors, are responsible for large numbers of deaths around the world. Chemotherapy is the most common approach used to treat advanced GI cancer. However, chemoresistance has emerged as a critical challenge that prevents successful tumor elimination, leading to metastasis and recurrence. Chemoresistance mechanisms are complex, and many factors and pathways are involved. Among these factors, non-coding RNAs (ncRNAs) are critical regulators of GI tumor development and subsequently can induce resistance to chemotherapy. This occurs because ncRNAs can target multiple signaling pathways, affect downstream genes, and modulate proliferation, apoptosis, tumor cell migration, and autophagy. ncRNAs can also induce cancer stem cell features and affect the epithelial-mesenchymal transition. Thus, ncRNAs could possibly act as new targets in chemotherapy combinations to treat GI cancer and to predict treatment response.

Reversion inducing cysteine rich protein with Kazal motifs and cardiovascular diseases: The RECKlessness of adverse remodeling

The Reversion Inducing Cysteine Rich Protein With Kazal Motifs (RECK) is a glycosylphosphatidylinositol (GPI) anchored membrane-bound regulator of matrix metalloproteinases (MMPs). It is expressed throughout the body and plays a role in extracellular matrix (ECM) homeostasis and inflammation. In initial studies, RECK expression was found to be downregulated in various invasive cancers and associated with poor prognostic outcome. Restoring RECK, however, has been shown to reverse the metastatic phenotype. Downregulation of RECK expression is also reported in non-malignant diseases, such as periodontal disease, renal fibrosis, and myocardial fibrosis. As such, RECK induction has therapeutic potential in several chronic diseases. Mechanistically, RECK negatively regulates various matrixins involved in cell migration, proliferation, and adverse remodeling by targeting the expression and/or activation of multiple MMPs, A Disintegrin And Metalloproteinase Domain-Containing Proteins (ADAMs), and A Disintegrin And Metalloproteinase With Thrombospondin Motifs (ADAMTS). Outside of its role in remodeling, RECK has also been reported to exert anti-inflammatory effects. In cardiac diseases, for example, it has been shown to counteract several downstream effectors of Angiotensin II (Ang-II) that play a role in adverse cardiac and vascular remodeling, such as Interleukin-6 (IL-6)/IL-6 receptor (IL-6R)/glycoprotein 130 (IL-6 signal transducer) signaling and Epidermal Growth Factor Receptor (EGFR) transactivation. This review article focuses on the current understanding of the multifunctional effects of RECK and how its downregulation may contribute to adverse cardiovascular remodeling.

AIMP3 inhibits cell growth and metastasis of lung adenocarcinoma through activating a miR-96-5p-AIMP3-p53 axis

Aminoacyl‐tRNA synthetase‐interacting multifunctional protein‐3 (AIMP3) is a tumour suppressor, however, the roles of AIMP3 in non‐small cell lung cancer (NSCLC) are not explored yet. Here, we reported that AIMP3 significantly inhibited the cell growth and metastasis of NSCLC (lung adenocarcinoma) in vitro and in vivo. We have firstly identified that AIMP3 was down‐regulated in human NSCLC tissues compared with adjacent normal lung tissues using immunohistochemistry and western blot assays. Overexpression of AIMP3 markedly suppressed the proliferation and migration of cancer cells in a p53‐dependent manner. Furthermore, we observed that AIMP3 significantly suppressed tumour growth and metastasis of A549 cells in xenograft nude mice. Mechanically, we identified that AIMP3 was a direct target of miR‐96‐5p, and we also observed that there was a negative correlation between AIMP3 and miR‐96‐5p expression in paired NSCLC clinic samples. Ectopic miR‐96‐5p expression promoted the proliferation and migration of cancer cells in vitro and tumour growth and metastasis in vivo which partially depended on AIMP3. Taken together, our results demonstrated that the axis of miR‐96‐5p‐AIMP3‐p53 played an important role in lung adenocarcinoma, which may provide a new strategy for the diagnosis and treatment of NSCLC.

Nanoceria, alone or in combination with cigarette-smoke condensate, induce transforming and epigenetic cancer-like features in vitro

Aim: To detect cell transformation effects of nanoceria after long-term exposure (up to 6 weeks) and to determine their potential interactions with cigarette smoke condensate, as a model of environmental carcinogenic pollutant. Materials & methods: Human bronchial epithelial BEAS-2 cells were used to determine transformation effects (invasion and tumorspheres induction), as well as changes in the expression of a battery of miRNAs related to the carcinogenesis process. Results: Nanoceria- and co-exposed cells exhibit cell transforming potential, with significantly increased invasion and tumorsphere formation abilities. Likewise, these exposures produced a high impact on the battery of miRNAs used. Conclusion: Nanoceria exposure induces cell-transformation and shows a positive interaction with the cell-transforming effects of cigarette smoke condensate. Besides, cerium dioxide nanoparticles and the co-exposure produced potential toxicity at the transcriptome level, which is related to tumorigenesis.

LncRNA MAGI2-AS3 is downregulated in non-small cell lung cancer and may be a sponge of miR-25

BACKGROUND

This study aimed to investigate the role of lncRNA MAGI2-AS3 in non-small cell lung cancer (NSCLC).

METHODS

Expression levels of MAGI2-AS3 and RECK mRNA in two types of tissues (non-tumor and NCSLC) were measured by qPCR. To further investigate the interaction between MAGI2-AS3 and RECK, MAGI2-AS3 and RECK expression vectors were transfected into H1993 cells.

RESULTS

We found that MAGI2-AS3 and RECK were upregulated and positively correlated in NSCLC. In NSCLC cells, MAGI2-AS3 overexpression led to upregulated RECK. Bioinformatics analysis showed that MAGI2-AS3 may bind miR-25, which can directly target RECK. In NSCLC cells, miR-25 overexpression led to downregulated RECK and attenuated the effects of MAGI2-AS3 overexpression, while MAGI2-AS3 and miR-25 failed to affect each other. Cell invasion and migration analysis showed decreased NSCLC cell invasion and migration rates after MAGI2-AS3 and RECK overexpression. MiR-25 showed opposite role and reduced the effects of MAGI2-AS3 overexpression.

CONCLUSION

Therefore, MAGI2-AS3 may sponge miR-25 to upregulate RECK, thereby inhibiting NSCLC cell invasion and migration.

TRIAL REGISTRATION

HLJCM20163358592, registered by First Affiliated Hospital, Heilongjiang University of Chinese Medicine at March 3, 2016, prospectively.

miR-96 enhances the proliferation of cervical cancer cells by targeting FOXO1

MiRNAs affect various biological pathways associated with the development, progression, clinical outcome and treatment response improvement in cervical cancer. This study was performed to evaluate the effects of miRNA 96 on cervical cancer and to clarify the mechanism. Vivo and vitro experiments were conducted in our trial. MiR-96 is upregulated in cervical cancer cell lines and cervical cancer tissues and is correlated with clinical features in cervical cancer patients. Overexpression of miR-96 enhances proliferation of cervical cancer cells, while inhibiting miR-96 reduces the proliferation of cervical cancer cells. Inhibition of miR-96 significantly decreased the percentage of cells in the S phase and increased the percentage of cells in G1/G0 peak in both SiHa and CaSki cells compared with NC cells and decreased the expressions of p21, p27 and cyclin D1. FOXO1 3'-UTR was sub cloned into a luciferase reporter vector and the putative miR-96 binding site in the FOXO1 3'-UTR was mutated. Treated with miR-96 inhibitor consistently enhanced the luciferase activity of the FOXO1 3'-UTR luciferase reporter plasmids in both SiHa and CaSki cells, whereas mutations in the miR-96-binding site abolished the effect. Vivo experiment also support these results. Therefore, inhibition of miR-96 might suppress growth, proliferation of CC cells and promote apoptosis of CC cells both in vitro and in vivo.

MicroRNA-96 is a potential tumor repressor by inhibiting NPTX2 in renal cell carcinoma

MicroRNA-96 (miR-96) is a vertebrate conserved microRNA which plays important roles in various cancers including renal cell carcinoma (RCC). However, its function and mechanism in RCC are still unclear. In this study, miR-96 was found to be downregulated in RCC based on The Cancer Genome Atlas datasets analyses, and its target genes, which predicted by TargetScan, were investigated. Among these target genes, neuronal pentraxin 2 (NPTX2) was upregulated more than 15-fold in RCC, and moreover, closely related to patient survival. To validate its targeting of NPTX2 experimentally, reverse transcription polymerase chain reaction, Western blot analysis, and dual-luciferase assays were performed, and results of these assays demonstrated that miR-96 inhibited expression of NPTX2 through a single 3'-untranslated region targeting site. Furthermore, transfection assays in RenCa and 786-O cells showed miR-96 and small interfering RNA of NPTX2 inhibited cell proliferation, migration, and invasion and overexpression of NPTX2 recovered the inhibition of miR-96. In conclusion, the present study reveals a novel regulatory mechanism of miR-96 on NPTX2 expression in RCC, and the potential of miR-96 as a RCC tumor repressor deserves further investigation.

Topologically inferring active miRNA-mediated subpathways toward precise cancer classification by directed random walk

Accurate predictions of classification biomarkers and disease status are indispensable for clinical cancer diagnosis and research. However, the robustness of conventional gene biomarkers is limited by issues with reproducibility across different measurement platforms and cohorts of patients. In this study, we collected 4775 samples from 12 different cancer datasets, which contained 4636 TCGA samples and 139 GEO samples. A new method was developed to detect miRNA‐mediated subpathway activities by using directed random walk (miDRW). To calculate the activity of each miRNA‐mediated subpathway, we constructed a global directed pathway network (GDPN) with genes as nodes. We then identified miRNAs with expression levels which were strongly inversely correlated with differentially expressed target genes in the GDPN. Finally, each miRNA‐mediated subpathway activity was integrated with the topological information, differential levels of miRNAs and genes, expression levels of genes, and target relationships between miRNAs and genes. The results showed that the proposed method yielded a more robust and accurate overall performance compared with other existing pathway‐based, miRNA‐based, and gene‐based classification methods. The high‐frequency miRNA‐mediated subpathways are more reliable in classifying samples and for selecting therapeutic strategies.

MALAT1 knockdown inhibits proliferation and enhances cytarabine chemosensitivity by upregulating miR-96 in acute myeloid leukemia cells

Drug resistance remains a major cause of relapse and therapeutic failure in acute myeloid leukemia (AML). Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been documented to act as an oncogene and is frequently highly expressed in human cancers including AML. However, the function and molecular mechanism of MALAT1 in regulating cytarabine (Ara-C) resistance of AML are largely unknown. The expressions of MALAT1 and miR-96 in AML patients and healthy controls were examined by qRT-PCR. CCK-8 and flow cytometry assay were performed to assess the proliferation and apoptosis of AML cells. The interaction between MALAT1 and miR-96 was investigated by luciferase reporter assay. We found that MALAT1 was upregulated while miR-96 was downregulated in AML patients compared with healthy controls. A negative correlation between MALAT1 and miR-96 expressions was observed in AML patients. Knockdown of MALAT1 inhibited the proliferation, induced apoptosis, and enhanced Ara-C sensitivity of AML cells. Additionally, MALAT1 suppressed miR-96 expression by acting as a molecular sponge of miR-96 in AML cells. miR-96 downregulation abolished the effects of MALAT1 knockdown on the proliferation, apoptosis, Ara-C sensitivity in AML cells. In conclusion, MALAT1 knockdown inhibited proliferation, promoted apoptosis and enhanced Ara-C sensitivity in AML cells by upregulating miR-96, providing novel insights into the critical role of MALAT1 as a miRNA sponge in AML.

Long non-coding RNA MEG3 suppresses the development of bladder urothelial carcinoma by regulating miR-96 and TPM1

We aimed at investigating effects of long non-coding RNA maternally expressed 3 (MEG3) on the proliferation, cell cycle and apoptosis of bladder urothelial carcinoma cells and regulatory relationships among lncRNA MEG3, miR-96 and α-tropomyosin 1 (TPM1). Human clinical data from The Cancer Genome Atlas (TCGA) which contains bladder urothelial carcinoma tissues and adjacent tissues were used for analysis. The expression profiles of MEG3, miR-96, TPM1, cell cycle-related genes and apoptosis-related genes were examined by real-time quantitative polymerase chain reaction (RT-qPCR) and western blot. Regulating relationship among MEG3, miR-96 and TPM1 was confirmed by dual luciferase reporter assay. MTT assay and flow cytometry were performed to observe cell proliferation, cell cycle and apoptosis. The effects of lncRNA MEG3 on bladder urothelial carcinoma were confirmed both in vivo and in vitro. The mRNA expression and protein expression of MEG3, TPM1 were down-regulated in carcinoma tissues, whereas miR-96 expression was up-regulated. MEG3 overexpression resulted in miR-96 downregulation along with TPM1 upregulation, which inhibited cell proliferation and cell cycle but promoted cell apoptosis of bladder urothelial carcinoma cells in vitro, and at the same time inhibited tumor growth in vivo. In this process, expressions of apoptosis-related protein BCL2 associated X (Bax), cleaved-caspase 3 was up-regulated, whereas apoptosis regulator protein (Bcl-2) expression was suppressed when MEG3 was overexpressed, and cell cycle-related protein Cyclin D1 was down-regulated. LncRNA MEG3 low-expression promotes the proliferation and inhibits apoptosis of bladder urothelial carcinoma cells by regulating miR-96 along with TPM1.

Functional validation of miRNAs targeting genes of DNA double-strand break repair to radiosensitize non-small lung cancer cells

DNA-Double strand breaks (DSBs) generated by radiation therapy represent the most efficient lesions to kill tumor cells, however, the inherent DSB repair efficiency of tumor cells can cause cellular radioresistance and impact on therapeutic outcome. Genes of DSB repair represent a target for cancer therapy since their down-regulation can impair the repair process making the cells more sensitive to radiation. In this study, we analyzed the combination of ionizing radiation (IR) along with microRNA-mediated targeting of genes involved in DSB repair to sensitize human non-small cell lung cancer (NSCLC) cells. MicroRNAs are natural occurring modulators of gene expression and therefore represent an attractive strategy to affect the expression of DSB repair genes. As possible IR-sensitizing targets genes we selected genes of homologous recombination (HR) and non-homologous end joining (NHEJ) pathway (i.e. RAD51, BRCA2, PRKDC, XRCC5, LIG1). We examined these genes to determine whether they may be real targets of selected miRNAs by functional and biological validation. The in vivo effectiveness of miRNA treatments has been examined in cells over-expressing miRNAs and treated with IR. Taken together, our results show that hsa-miR-96-5p and hsa-miR-874-3p can directly regulate the expression of target genes. When these miRNAs are combined with IR can decrease the survival of NSCLC cells to a higher extent than that exerted by radiation alone, and similarly to radiation combined with specific chemical inhibitors of HR and NHEJ repair pathway.

Stabilization of miRNAs in esophageal cancer contributes to radioresistance and limits efficacy of therapy

The five-year survival rate of esophageal cancer patients is less than 20%. This may be due to increased resistance (acquired or intrinsic) of tumor cells to chemo/radiotherapies, often caused by aberrant cell cycle, deregulated apoptosis, increases in growth factor signaling pathways, and/or changes in the proteome network. In addition, deregulation in non-coding RNA-mediated signaling pathways may contribute to resistance to therapies. At the molecular level, these resistance factors have now been linked to various microRNA (miRNAs), which have recently been shown to control cell development, differentiation and neoplasia. The increased stability and dysregulated expression of miRNAs have been associated with increased resistance to various therapies in several cancers, including esophageal cancer. Therefore, miRNAs represent the next generation of molecules with tremendous potential as biomarkers and therapeutic targets. However, detailed studies on miRNA-based therapeutic interventions are still in their infancy. Hence, in this review, we have summarized the current status of microRNAs in dictating the resistance/sensitivity of tumor cells to chemotherapy and radiotherapy. In addition, we have discussed various strategies to increase radiosensitivity, including targeted therapy, and the use of miRNAs as radiosensitive/radioresistance biomarkers for esophageal cancer in the clinical setting.

MicroRNA-96 expression induced by low-dose cisplatin or doxorubicin regulates chemosensitivity, cell death and proliferation in gastric cancer SGC7901 cells by targeting FOXO1

MicroRNA-96 (miR-96) is transcriptionally associated with the induction of chemoresistance following chemotherapy by targeting to FOXO1 mRNA at one of two predicted binding sites in its 3'-untranslated region sequence. The upregulation of miR-96 is associated with a high risk of chemoresistance. Nevertheless, the mechanism by which miR-96 is upregulated remains largely undefined. In the present study, the gastric cancer SGC7901 cell line was treated with different doses of the chemotherapeutic agents cisplatin and doxorubicin. miR-96 expression was analyzed by reverse transcription-quantitative polymerase chain reaction at different time points. Western blot and chromatin immunoprecipitation were performed to analyze the expression levels of the target gene. The effects of miR-96 on chemosensitivity were assessed by a carboxyfluorescein succinimidyl ester/propidium iodide labeling assay, and its effects on proliferation were assessed by Cell Counting Kit-8 or EdU staining assays. The results demonstrated that treatment with a low dose of either chemotherapeutic agent induced miR-96 expression. Upregulation of miR-96 caused the post-transcriptional repression of FOXO1 expression. Decreases in FOXO1 protein levels led to a decrease in the transcriptional activity of the cyclin-dependent kinase inhibitor 1A (CDKN1A, also known as p21) promoter region, and thus the expression of p21 was downregulated in a tumor protein p53-independent manner. As a result, induction of miR-96 expression caused chemoresistance and promoted proliferation in SGC7901 cells. Taken together, the results of the present study revealed that treatment with cisplatin or doxorubicin could induce expression of miR-96 at certain doses. Upregulation of miR-96 is partially associated with chemoresistance and miR-96 can also promote cell proliferation by repressing p21.

Construction of a specific SVM classifier and identification of molecular markers for lung adenocarcinoma based on lncRNA-miRNA-mRNA network

Background

Novel diagnostic predictors and drug targets are needed for LUAD (lung adenocarcinoma). We aimed to build a specific SVM (support vector machine) classifier for diagnosis of LUAD and identify molecular markers with prognostic value for LUAD.

Methods

The expression differences of miRNAs, lncRNAs and mRNAs between LUAD and normal samples were compared using data from TCGA (The Cancer Genome Atlas) database. A LUAD related miRNA-lncRNA-mRNA network was constructed, based on which feature genes were selected for the construction of LUAD specific SVM classifier. The robustness and transferability of SVM classifier were validated using gene expression profile datasets GSE43458 and GSE10072. Prognostic markers were identified from the network. A set of LUAD-related differentially expressed miRNAs, lncRNAs and miRNAs were identified and a LUAD related miRNA-lncRNA-mRNA network was obtained. The LUAD specific SVM classifier constructed on the basis of the network was robust and efficient for classification of samples from TCGA dataset and two independent validation datasets.

Results

Eight RNAs with prognostic value were identified, including hsa-miR-96, hsa-miR-204, PGM5P2 (phosphoglucomutase 5 pseudogene 2), SFTA1P (surfactant associated 1), RGS20 (regulator of G protein signaling 20), RGS9BP (RGS9-binding protein), FGB (fibrinogen beta chain) and INA (alpha-internexin). Among them, RGS20 and INA were regulated by hsa-miR-96. RGS20 was also regulated by hsa-miR-204, which was a potential target of SFTA1P.

Conclusion

The LUAD specific SVM classifier may serve as a novel diagnostic predictor. hsa-miR-96, hsa-miR-204, PGM5P2, SFTA1P, RGS20, RGS9BP, FGB and INA may serve as prognostic markers in clinical practice.

miR-96 promotes invasion and metastasis by targeting GPC3 in non-small cell lung cancer cells

Lung cancer is a major cause of death worldwide, and non-small cell lung cancer (NSCLC) is the most common type of lung cancer. The aim of this study was to investigate whether miR-96 mediated the invasion and metastasis of NSCLC by targeting glypican-3 (GPC3). Reverse transcription-quantitative PCR (RT-qPCR) was employed to detect the level of miR-96 and GPC3 mRNA. We applied western blot analysis to measure the protein expression level of GPC3 gene. The luciferase reporter assay was employed to confirm that GPC3 was a target gene of miR-96. The Transwell assay was used to detect migration and invasion. The results revealed that miR-96 was upregulated in NSCLC tissues and lung cancer cells (A549 and H460) compared with corresponding paracancerous tissues and normal epidermic MRC-5 cells. Overexpression of miR-96 promoted invasion and migration in A549 cells. GPC3 was a direct target of miR-96 and regulated by miR-96. GPC3 could reverse partial fuction of miR-96 on proliferation. In conclusion, miR-96 was able to promote the migration and invasion of lung cancer cells by targeting GPC3 gene. The newly identified miR-96/GPC3 axis may provide a therapeutic method for the treatment of NSCLC.

MiR-96 regulates bone metabolism by targeting osterix

MicroRNAs (miRNAs) play important roles in bone metabolism and aging. Here we show that miR-96 was markedly up-regulated in serum of elderly patients with osteoporosis by miRNA microarray analysis and qRT-PCR. Moreover miR-96 was also up-regulated in bone marrow mesenchymal stem cells (BMSCs) of aged humans and mice. Our results show that the over-expression of miR-96 reduced osteogenic differentiation of BMSCs, whereas the inhibition of miR-96 increased osteogenic differentiation of BMSCs. At the molecular level, miR-96 regulated osteogenesis by targeting osterix. Interestingly, over-expression of miR-96 in young mice by intravenous injection of agomiR-96 developed a low bone mass due to impaired osteogenesis. However, inhibition of miR-96 in aged mice attenuated the age-related bone loss. Thus, our data suggest that miR-96 regulates osteogenesis and may represent a potential diagnostic marker or therapeutic target for age-related bone loss.

MiR-96 enhances cellular proliferation and tumorigenicity of human cervical carcinoma cells through PTPN9

Up to date, the cervical cancer remains to be one of the leading gynecological malignancies worldwide. MicroRNAs (miRNAs) play critical roles in the process of tumor initiation and progression. However, miR-96 has rarely been investigated in human cervical carcinoma. We aimed to investigate the biological function and underlying molecular mechanism of miR-96 in human cervical carcinoma. MiR-96 levels were determined by qRT-PCR. Protein tyrosine phosphatase, non-receptor type 9 (PTPN9) mRNA and protein levels were investigated by qRT-PCR and western blotting. The cellular proliferation in cervical cells was monitored by CyQuant assay. Soft agar assay was employed to determine the tumorigenicity. 3' UTR luciferase assay was used to validate the target gene of miR-96. SPSS was used to analyze statistical significance in different treatment. MiR-96 was dramatically upregulated in human cervical tumor tissues. Overexpression of miR-96 was found to significantly promote the cellular proliferation and tumorigenicity of cervical cells. Furthermore, we showed that PTPN9 was a direct target gene of miR-96 and had opposite effect to those of miR-96 on cervical cells. MiR-96 may promote the cellular proliferation and tumorigenicity of cervical cells by silencing PTPN9. Our study highlights an importantly regulatory role of miR-96 and suggests that an appropriate manipulation of miR-96 may be a new treatment of human cervical carcinoma in the future.

miR-15b-5p facilitates the tumorigenicity by targeting RECK and predicts tumour recurrence in prostate cancer

MicroRNAs (miRNAs) have been reported to participate in many biological behaviours of multiple malignancies. Recent studies have shown that miR‐15b‐5p (miR‐15b) exhibits dual roles by accelerating or blocking tumour progression. However, the molecular mechanisms by which miR‐15b contributes to prostate cancer (PCa) are still elusive. Here, miR‐15b expression was found significantly up‐regulated in PCa in comparison with the normal samples and was positively correlated with age and Gleason score in patients with PCa. Notably, PCa patients with miR‐15b high expression displayed a higher recurrence rate than those with miR‐15b low expression (P = 0.0058). Knockdown of miR‐15b suppressed cell growth and invasiveness in 22RV1 and PC3 cells, while overexpression of miR‐15b reversed these effects. Then, we validated that RECK acted as a direct target of miR‐15b by dual‐luciferase assay and revealed the negative correlation of RECK with miR‐15b expression in PCa tissues. Ectopic expression of RECK reduced cell proliferation and invasive potential and partially abrogated the tumour‐promoting effects caused by miR‐15b overexpression. Additionally, miR‐15b knockdown inhibited tumour growth activity in a mouse PCa xenograft model. Taken together, our findings indicate that miR‐15b promotes the progression of PCa cells by targeting RECK and represents a potential marker for patients with PCa.

Dysregulation and functional roles of miR-183-96-182 cluster in cancer cell proliferation, invasion and metastasis

Previous studies have reported aberrant expression of the miR-183-96-182 cluster in a variety of tumors, which indicates its' diagnostic or prognostic value. However, a key characteristic of the miR-183-96-182 cluster is its varied expression levels, and pleomorphic functional roles in different tumors or under different conditions. In most tumor types, the cluster is highly expressed and promotes tumorigenesis, cancer progression and metastasis; yet tumor suppressive effects have also been reported in some tumors. In the present study, we discuss the upstream regulators and the downstream target genes of miR-183-96-182 cluster, and highlight the dysregulation and functional roles of this cluster in various tumor cells. Newer insights summarized in this review will help readers understand the different facets of the miR-183-96-182 cluster in cancer development and progression.

Anticancer effect of miR-96 inhibitor in bladder cancer cell lines

The present study aimed to investigate the role of microRNA-96 (miR-96) in the proliferation, invasion and apoptosis of bladder cancer cell lines, and the associated mechanisms. The expression of miR-96 and human ether-à-go-go-related (HERG1) potassium channel in the normal uroepithelium SV-HUC-1 cell line, and bladder cancer T24 and 5637 cell lines were examined using reverse transcription-polymerase chain reaction or/and western blotting. Transfection with miR-96 inhibitor or scrambled control (SC) was used to study the biological activities of miR-96 in bladder cancer cell lines. MTT, flow cytometric and Transwell assays were applied to detect cell viability, apoptosis and invasion, respectively. A dual-luciferase reporter assay was applied to determine the association between miR-96 and HERG1 expression. As demonstrated, miR-96 was highly expressed in the two bladder cancer cell lines, particularly in T24 cells. Following transfection with miR-96 inhibitor, miR-96 expression was significantly reduced in the T24 cell line, compared with SC. The miR-96 inhibitor suppressed cell proliferation and invasion, promoted apoptosis and arrested the cell cycle at the G₁ phase. Consistently, HERG1 was also highly expressed in the two bladder cancer cell lines at the mRNA and protein level, but not in the normal uroepithelium cell line. The miR-96 inhibitor also significantly decreased HERG1 expression compared with SC. The results of the dual-luciferase reporter assay indicated that miR-96 directly targeted wild-type HERG1. In conclusion, miR-96 inhibitor exhibited anticancer effects on bladder cancer cells by inhibiting proliferation and invasion of cells, and promoting their apoptosis. HERG1 was an important target of miR-96. These results provided experimental evidence supporting miR-96 as a therapeutic target for patients with bladder cancer.

miR-96-5p prevents hepatic stellate cell activation by inhibiting autophagy via ATG7

Activation of hepatic stellate cell (HSC), which is the main source of extracellular matrix, plays a pivotal role in liver fibrogenesis. Autophagy of hepatic stellate cell has been recently implicated in liver fibrosis, but the regulation of hepatic stellate cell autophagy during this process remains poorly understood. Here, we first identified miR-96-5p as an aberrantly expressed miRNA in fibrotic liver tissues. Next, we transfected miR-96-5p mimic into human hepatic stellate cell line LX-2 and observed decreased protein and mRNA levels of α-SMA and Col1A1. In addition, transfection of miR-96-5p mimic significantly reduced autophagy activity of LX-2 cells, while transfection of miR-96-5p inhibitor promoted LX-2 cell autophagy. Moreover, autophagy-related protein 7 (ATG7) was predicted as a potential target of miR-96-5p and luciferase assay confirmed its direct interaction with miR-96-5p. Finally, reintroduction of ATG7 into LX-2 cells reversed miR-96-5p-mediated inhibition of autophagy as well as α-SMA and Col1A1 expression. In conclusion, we demonstrated that miR-96-5p can inhibit hepatic stellate cell activation by blocking autophagy via ATG7. These findings provide new insight into the development of miRNA-based anti-fibrotic strategies.

KEY MESSAGES

• Altered miRNA expression profile is observed in fibrotic liver tissues. • miR-96-5p can inhibit HSC activation. • Autophagy of HSC is repressed by miR-96-5p during activation. • ATG7 is a direct target of miR-96-5p. • ATG7 can rescue miR-96-5p-mediated inhibition of autophagy and HSC activation.

Identification and characterization of miR-96, a potential biomarker of NSCLC, through bioinformatic analysis

Lung cancer is the leading cause of cancer-related death worldwide. The poor prognosis is partly due to lack of efficient methods for early diagnosis. MicroRNAs play roles in almost all aspects of cancer biology, and can be secreted into the circulation and serve as molecular biomarkers for the early diagnosis of cancer. In the present study, we determined the expression of miR-96 and the function of its target genes in lung cancer through bioinformatic analysis. Four microRNA expression profiles of lung cancer were downloaded from Gene Expression Omnibus and the data were analyzed using SPSS 16.0 software. Compared to the control group, expression of miR-96 was significantly increased in non-small cell lung cancer (NSCLC) (GSE51855), lung adenocarcinoma (GSE48414), stage I adenocarcinoma tissues (GSE63805) and the plasma of lung cancer patients (GSE68951). miR-96 was also elevated in six different NSCLC cell lines. However, the expression level of miR-96 was not related to the age, gender, clinical stage and histological subtype of the NSCLC patients. GO analysis of 78 predicted target genes of miR-96 showed that 42 of the obtained GO terms are highly associated with specific cellular processes including response to stimulus, signaling pathway, cell division, cell communication, cell migration and calcium signaling. KEGG results indicated that the miR-96 targets are mainly involved in the GnRH signaling pathway, long-term potentiation and insulin signaling pathway. In conclusion, miR-96, functioning as an oncogene, may play an important role in the development and progression of lung cancer. miR-96 may have the potential to serve as a molecular biomarker for the early diagnosis of NSCLC.

Circulating exosomal microRNA-96 promotes cell proliferation, migration and drug resistance by targeting LMO7

Detection and treatment of lung cancer still remain a clinical challenge. This study aims to validate exosomal microRNA-96 (miR-96) as a serum biomarker for lung cancer and understand the underlying mechanism in lung cancer progression. MiR-96 expressions in normal and lung cancer patients were characterized by qPCR analysis. Changes in cell viability, migration and cisplatin resistance were monitored after incubation with isolated miR-96-containing exosomes, anti-miR-96 and anti-miR negative control (anti-miR-NC) transfections. Dual-luciferase reporter assay was used to study interaction between miR-96 and LIM-domain only protein 7 (LMO7). Changes induced by miR-96 transfection and LMO7 overexpression were also evaluated. MiR-96 expression was positively correlated with high-grade and metastatic lung cancers. While anti-miR-96 transfection exhibited a tumour-suppressing function, exosomes isolated from H1299 enhanced cell viability, migration and cisplatin resistance. Potential miR-96 binding sites were found within the 3'-UTR of wild-type LMO7 gene, but not of mutant LMO7 gene. LMO7 expression was inversely correlated with lung cancer grades, and LMO7 overexpression reversed promoting effect of miR-96. We have identified exosomal miR-96 as a serum biomarker of malignant lung cancer. MiR-96 promotes lung cancer progression by targeting LMO7. The miR-96-LMO7 axis may be a therapeutic target for lung cancer patients, and new diagnostic or therapeutic strategies could be developed by targeting the miR-96-LMO7 axis.

miR-96 promotes cell proliferation, migration and invasion by targeting PTPN9 in breast cancer

microRNAs (miRNAs) have emerged as major regulators of the initiation and progression of human cancers, including breast cancer. The aim of this study is to determine the expression pattern of miR-96 in breast cancer and to investigate its biological role during tumorigenesis. We showed that miR-96 was significantly upregulated in breast cancer. We then investigated its function and found that miR-96 significantly promoted cell proliferation, migration and invasion in vitro and enhanced tumor growth in vivo. Furthermore, we explored the molecular mechanisms by which miR-96 contributes to breast cancer progression and identified PTPN9 (protein tyrosine phosphatase, non-receptor type 9) as a direct target gene of miR-96. Finally, we showed that PTPN9 had opposite effects to those of miR-96 on breast cancer cells, suggesting that miR-96 may promote breast tumorigenesis by silencing PTPN9. Taken together, this study highlights an important role for miR-96 in the regulation of PTPN9 in breast cancer cells and may provide insight into the molecular mechanisms of breast carcinogenesis.

Local microRNA delivery targets Palladin and prevents metastatic breast cancer

Metastasis is the primary cause for mortality in breast cancer. MicroRNAs, gene expression master regulators, constitute an attractive candidate to control metastasis. Here we show that breast cancer metastasis can be prevented by miR-96 or miR-182 treatment, and decipher the mechanism of action. We found that miR-96/miR-182 downregulate Palladin protein levels, thereby reducing breast cancer cell migration and invasion. A common SNP, rs1071738, at the miR-96/miR-182-binding site within the Palladin 3'-UTR abolishes miRNA:mRNA binding, thus diminishing Palladin regulation by these miRNAs. Regulation is successfully restored by applying complimentary miRNAs. A hydrogel-embedded, gold-nanoparticle-based delivery vehicle provides efficient local, selective, and sustained release of miR-96/miR-182, markedly suppressing metastasis in a breast cancer mouse model. Combined delivery of the miRNAs with a chemotherapy drug, cisplatin, enables significant primary tumour shrinkage and metastasis prevention. Our data corroborate the role of miRNAs in metastasis, and suggest miR-96/miR-182 delivery as a potential anti-metastatic drug.

Migration and epithelial-to-mesenchymal transition of lung cancer can be targeted via translation initiation factors eIF4E and eIF4GI

Metastasis underlies cancer morbidity and accounts for disease progression and significant death rates generally and in non-small cell lung cancer (NSCLC) particularly. Therefore, it is critically important to understand the molecular events that regulate metastasis. Accumulating data portray a central role for protein synthesis, particularly translation initiation (TI) factors eIF4E and eIF4G in tumorigenesis and patients' survival. We have published that eIF4E/eIF4GI activities and consequently NSCLC cell migration are modulated by bone-marrow mesenchymal stem cell secretomes, suggesting a role for TI in metastasis. Here, we aimed to expand our understanding of the TI factors significance to NSCLC characteristics, particularly epithelial-to-mesenchymal transition (EMT) and migration, supportive of metastasis. In a model of NSCLC cell lines (H1299, H460), we inhibited eIF4E/eIF4GI's expressions (siRNA, ribavirin) and assessed NSCLC cell lines' migration (scratch), differentiation (EMT, immunoblotting), and expression of select microRNAs (qPCR). Initially, we determined an overexpression of several TI factors (eIF4E, eIF4GI, eIF4B, and DHX29) and their respective targets in NSCLC compared with normal lung samples (70-350%↑, P<0.05). Knockdown (KD) of eIF4E/eIF4GI in NSCLC cell lines (70%↓, P<0.05) also manifested in decreased target levels (ERα, SMAD5, NFkB, CyclinD1, c-MYC, and HIF1α) (20-50%↓, P<0.05). eIF4E/eIF4GI KD also attenuated cell migration (60-75%↓, P<0.05), EMT promoters (15-90%↓, P<0.05), and enhanced EMT suppressors (30-380%↑, P<0.05). The importance of eIF4E KD to NSCLC phenotype was further corroborated with its inhibitor, ribavirin. Changes in expression of essential microRNAs implicated in NSCLC cell migration concluded the study (20-100%, P<0.05). In summary, targeting eIF4E/eIF4GI reduces migration and EMT, both essential for metastasis, thereby underscoring the potential of TI targeting in NSCLC therapy, especially the already clinically employed agents (ribavirin/4EGI). Comparison of these findings with previously reported effects of eIF4E/eIF4GI KD in multiple myeloma suggests a collective role for these TI factors in cancer progression.

MicroRNA-96 Regulates Apoptosis by Targeting PDCD4 in Human Glioma Cells

Glioblastoma multiforme, the most common and aggressive form of primary brain tumor, presents a dismal prognosis. MicroRNAs play a critical role in the initiation, progression, and metastasis of cancer; however, the potential biological role of miRNAs in glioblastoma multiforme remains largely unknown. In our study, we found that microRNA-96 is upregulated in glioma tissues than in normal human brains. Transfection of microRNA-96 mimics into glioma cells significantly decreases apoptosis by suppressing PDCD4, a well-known tumor suppressor that is involved in apoptosis. In contrast, knockdown of microRNA-96 enhanced apoptosis. In vivo, microRNA-96 overexpression inhibits the apoptosis and increases tumor growth. These data suggest that microRNA-96 is a potential molecular target for glioma treatment.

Bioinformatic Studies to Predict MicroRNAs with the Potential of Uncoupling RECK Expression from Epithelial-Mesenchymal Transition in Cancer Cells

RECK is downregulated in many tumors, and forced RECK expression in tumor cells often results in suppression of malignant phenotypes. Recent findings suggest that RECK is upregulated after epithelial-mesenchymal transition (EMT) in normal epithelium-derived cells but not in cancer cells. Since several microRNAs (miRs) are known to target RECK mRNA, we hypothesized that certain miR(s) may be involved in this suppression of RECK upregulation after EMT in cancer cells. To test this hypothesis, we used three approaches: (1) text mining to find miRs relevant to EMT in cancer cells, (2) predicting miR targets using four algorithms, and (3) comparing miR-seq data and RECK mRNA data using a novel non-parametric method. These approaches identified the miR-183-96-182 cluster as a strong candidate. We also looked for transcription factors and signaling molecules that may promote cancer EMT, miR-183-96-182 upregulation, and RECK downregulation. Here we describe our methods, findings, and a testable hypothesis on how RECK expression could be regulated in cancer cells after EMT.

RECK (reversion-inducing cysteine-rich protein with Kazal motifs) regulates migration, differentiation and Wnt/β-catenin signaling in human mesenchymal stem cells

The membrane-anchored glycoprotein RECK (reversion-inducing cysteine-rich protein with Kazal motifs) inhibits expression and activity of certain matrix metalloproteinases (MMPs), thereby suppressing tumor cell metastasis. However, RECK's role in physiological cell function is largely unknown. Human mesenchymal stem cells (hMSCs) are able to differentiate into various cell types and represent promising tools in multiple clinical applications including the regeneration of injured tissues by endogenous or transplanted hMSCs. RNA interference of RECK in hMSCs revealed that endogenous RECK suppresses the transcription and biosynthesis of tissue inhibitor of metalloproteinases (TIMP)-2 but does not influence the expression of MMP-2, MMP-9, membrane type (MT)1-MMP and TIMP-1 in these cells. Knockdown of RECK in hMSCs promoted monolayer regeneration and chemotactic migration of hMSCs, as demonstrated by scratch wound and chemotaxis assay analyses. Moreover, expression of endogenous RECK was upregulated upon osteogenic differentiation and diminished after adipogenic differentiation of hMSCs. RECK depletion in hMSCs reduced their capacity to differentiate into the osteogenic lineage whereas adipogenesis was increased, demonstrating that RECK functions as a master switch between both pathways. Furthermore, knockdown of RECK in hMSCs attenuated the Wnt/β-catenin signaling pathway as indicated by reduced stability and impaired transcriptional activity of β-catenin. The latter was determined by analysis of the β-catenin target genes Dickkopf1 (DKK1), axis inhibition protein 2 (AXIN2), runt-related transcription factor 2 (RUNX2) and a luciferase-based β-catenin-activated reporter (BAR) assay. Our findings demonstrate that RECK is a regulator of hMSC functions suggesting that modulation of RECK may improve the development of hMSC-based therapeutical approaches in regenerative medicine.

Promotion of tumour proliferation, migration and invasion by miR-92b in targeting RECK in osteosarcoma

MicroRNAs play important roles in the development of cancers. Although miR-92b has been reported to promote the tumorigenesis of some cancers, its role in osteosarcoma remains unknown. In the present study, we focused on the expression, function and mechanisms of miR-92b in osteosarcoma development. The miRNA miR-92b was up-regulated in osteosarcoma cell lines and tissues; miR-92b up-regulation correlated with poor prognosis in osteosarcoma. Overexpression of miR-92b promoted osteosarcoma cell proliferation, migration and invasion, which was abrogated by miR-92b inhibition. Reversion-inducing, cysteine-rich protein with kazal motifs (RECK) was identified as the direct and functional target of miR-92b in osteosarcoma. Importantly, restoring RECK expression abrogated increases in cell growth, motility and invasiveness induced by miR-92b RECK was down-regulated in osteosarcoma tissues, and its expression level negatively correlated with miR-92b Collectively, our results indicate that miR-92b acts as an oncogenic miRNA and may be a therapeutic target in osteosarcoma.

Upregulation of microRNA-96 and its oncogenic functions by targeting CDKN1A in bladder cancer

Background

Genome-wide miRNA expression profile has identified microRNA (miR)-96 as one of upregulated miRNAs in clinical bladder cancer (BC) tissues compared to normal bladder tissues. The aim of this study was to confirm the expression pattern of miR-96 in BC tissues and to investigate its involvement in carcinogenesis.

Methods

Quantitative real-time PCR was performed to detect the expression levels of miR-96 in 60 BC and 40 normal control tissues. Bioinformatics prediction combined with luciferase reporter assay were used to verify whether the cyclin-dependent kinase inhibitor CDKN1A was a potential target gene of miR-96. Cell counting kit-8 and apoptosis assays were further performed to evaluate the effects of miR-96-CDKN1A axis on cell proliferation and apoptosis of BC cell lines.

Results

We validated that miR-96 was significantly increased in both human BC tissues and cell lines. According to the data of miRTarBase, CDKN1A might be a candidate target gene of miR-96. In addition, luciferase reporter and Western blot assays respectively demonstrated that miR-96 could bind to the putative seed region in CDKN1A mRNA 3′UTR, and significantly reduce the expression level of CDKN1A protein. Moreover, we found that the inhibition of miR-96 expression remarkably decreased cell proliferation and promoted cell apoptosis of BC cell lines, which was consistent with the findings observed following the introduction of CDKN1A cDNA without 3′UTR restored miR-96.

Conclusions

Our data reveal that miR-96 may function as an onco-miRNA in BC. Upregulation of miR-96 may contribute to aggressive malignancy partly through suppressing CDKN1A protein expression in BC cells.

miR-96 suppresses renal cell carcinoma invasion via downregulation of Ezrin expression

BACKGROUND

The present study examined the role of microRNA (miR)-96 in renal cell carcinoma (RCC) invasion.

METHODS

The expression of miR-96 was detected by quantitative reverse transcription-polymerase chain reaction in human RCC cell lines with high (Caki-1) and low (786-O) metastatic potential. Invasive ability and Ezrin expression were assessed in Caki-1 and 786-O cells transfected with a miR-96 mimic or inhibitor using wound healing assays, Transwell assays and western blotting. Expression of miR-96 and Ezrin was also examined in primary RCC samples from 17 patients with metastatic disease and 46 patients who maintained remission during a follow-up period of 37 months.

RESULTS

miR-96 expression was significantly lower in Caki-1compared to786-O cells. The invasive ability of Caki-1 and 786-O cells increased following transfection of cells with miR-96 inhibitor, whereas it decreased following transfection with miR-96 mimic. Ezrin levels were negatively correlated with miR-96 in RCC, and inhibition of Ezrin expression suppressed the miR-96-induced change in invasive ability. The negative correlation between miR-96 and metastasis/Ezrin expression was also observed in human RCC specimens.

CONCLUSIONS

These results suggest that miR-96 suppresses RCC invasion by modulating Ezrin expression.

The microRNA-183 cluster: the family that plays together stays together

The microRNA (miR)183 cluster, which is comprised of miRs-183, -96 and -182, is also a miR family with sequence homology. Despite the strong similarity in the sequences of these miRs, minute differences in their seed sequences result in both overlapping and distinct messenger RNA targets, which are often within the same pathway. These miRs have tightly synchronized expression during development and are required for maturation of sensory organs. In comparison to their defined role in normal development, the miR-183 family is frequently highly expressed in a variety of non-sensory diseases, including cancer, neurological and auto-immune disorders. Here, we discuss the conservation of the miR-183 cluster and the functional role of this miR family in normal development and diseases. We also describe the regulation of vital cellular pathways by coordinated expression of these miR siblings. This comprehensive review sheds light on the likely reasons why the genomic organization and seeming redundancy of the miR-183 family cluster was conserved through 600 million years of evolution.

Identification and Functional Validation of Reciprocal microRNA-mRNA Pairings in African American Prostate Cancer Disparities

PURPOSE

African Americans (AA) exhibit higher rates of prostate cancer incidence and mortality compared with European American (EA) men. In addition to socioeconomic influences, biologic factors are believed to play a critical role in prostate cancer disparities. We investigated whether population-specific and -enriched miRNA-mRNA interactions might contribute to prostate cancer disparities.

EXPERIMENTAL DESIGN

Integrative genomics was used, combining miRNA and mRNA profiling, miRNA target prediction, pathway analysis, and functional validation, to map miRNA-mRNA interactions associated with prostate cancer disparities.

RESULTS

We identified 22 AA-specific and 18 EA-specific miRNAs in prostate cancer versus patient-matched normal prostate, and 10 "AA-enriched/-depleted" miRNAs in AA prostate cancer versus EA prostate cancer comparisons. Many of these population-specific/-enriched miRNAs could be paired with target mRNAs that exhibited an inverse pattern of differential expression. Pathway analysis revealed EGFR (or ERBB) signaling as a critical pathway significantly regulated by AA-specific/-enriched mRNAs and miRNA-mRNA pairings. Novel miRNA-mRNA pairings were validated by qRT-PCR, Western blot, and/or IHC analyses in prostate cancer specimens. Loss/gain of function assays performed in population-specific prostate cancer cell lines confirmed miR-133a/MCL1, miR-513c/STAT1, miR-96/FOXO3A, miR-145/ITPR2, and miR-34a/PPP2R2A as critical miRNA-mRNA pairings driving oncogenesis. Manipulating the balance of these pairings resulted in decreased proliferation and invasion, and enhanced sensitization to docetaxel-induced cytotoxicity in AA prostate cancer cells.

CONCLUSIONS

Our data suggest that AA-specific/-enriched miRNA-mRNA pairings may play a critical role in the activation of oncogenic pathways in AA prostate cancer. Our findings also suggest that miR-133a/MCL1, miR-513c/STAT1, and miR-96/FOXO3A may have clinical significance in the development of novel strategies for treating aggressive prostate cancer.

MicroRNA-575 targets BLID to promote growth and invasion of non-small cell lung cancer cells

This study was designed to detect miR-575 expression and function in non-small cell lung cancer (NSCLC). A higher expression of miR-575 in NSCLC tissues was observed compared with adjacent non-neoplastic tissues. Furthermore, re-introduction of miR-575 significantly promoted cell proliferation, migration, and invasion in the NSCLC line. Moreover, we showed that BLID is negatively regulated by miR-575 at the posttranscriptional level, via a specific target site within the 3'UTR. Overexpression of BLID counteracted miR-575-induced proliferation and invasion in NSCLC cells. The expression of BLID is frequently downregulated in NSCLC tumors and cell lines and inversely correlates with miR-575 expression. The findings of this study contribute to the current understanding of the functions of miR-575 in NSCLC.

miR-96 promotes osteogenic differentiation by suppressing HBEGF-EGFR signaling in osteoblastic cells

MicroRNAs (miRNAs) are a class of small non-coding RNAs with important roles in various biological and pathological processes, including osteoblast differentiation. Here, we identified miR-96 as a positive regulator of osteogenic differentiation in a mouse osteoblastic cell line (MC3T3-E1) and in mouse bone marrow-derived mesenchymal stem cells. Moreover, we found that miR-96 down-regulates post-transcriptional expression of heparin-binding EGF-like growth factor (HB-EGF) by specifically binding to the 3'untranslated region of HB-EGF mRNA. Furthermore, in MC3T3-E1 cells, miR-96-induced HB-EGF down-regulation suppressed the phosphorylation of epidermal growth factor receptor (EGFR) and of extracellular signal-regulated kinase 1 (ERK1) and AKT, which both lie downstream of EGFR activation. Taken together, miR-96 promotes osteogenic differentiation by inhibiting HB-EGF and by blocking the HB-EGF-EGFR signaling pathway in osteoblastic cells.

MiR-96 promotes proliferation and chemo- or radioresistance by down-regulating RECK in esophageal cancer

The involvement of miR-96 in esophageal cancer (EC) remains unclear. The aim of this study is to explore the functional role of miR-96 and determine whether miR-96 could be a potential therapeutic target for human esophageal cancer. MiR-96 up-regulation was demonstrated in 145 EC samples and RECK down-regulation was validated in EC cell lines. Moreover, ectopic overexpression of miR-96 in TE-1 or ECa-109 contributed to tumor growth in xenograft mouse models. Furthermore, up-regulation of miR-96 could reduce the susceptibilities of EC cells to chemotherapy or radiotherapy. RECK was identified as a target of miR-96 and RECK overexpressing could abrogate the growth of EC cells induced by miR-96. Taken together, miR-96 serves as an oncogene role in EC cells through downregulating RECK.

MicroRNA-27b suppresses growth and invasion of NSCLC cells by targeting Sp1

Non-small cell lung cancer (NSCLC) is the major cause of cancer death worldwide. Increasing evidence shows that microRNAs (miRNAs), evolutionally conserved non-coding RNAs, are widely involved in the development and progression of NSCLC. Aberrant alteration of miRNAs expression has been implicated in NSCLC initiation and progression. Herein, we studied the role of miR-27b in NSCLC cells. We found that miR-27b was significantly decreased in several NSCLC cell lines. Forced overexpression of miR-27 inhibited both the growth and invasion of NSCLC cells. Furthermore, we identified Sp1 transcription factor (Sp1) as a target of miR-27b in NSCLC cells. Moreover, we found that miR-27 suppressed growth and invasion of NSCLC cells partially by targeting Sp1. Our data indicate that miR-27b may play a critical role in the development of NSCLC.

miR-143 inhibits NSCLC cell growth and metastasis by targeting Limk1

MicroRNAs (miRNAs) have essential roles in carcinogenesis and tumor progression. Here, we investigated the roles and mechanisms of miR-143 in non-small cell lung cancer (NSCLC). miR-143 was significantly decreased in NSCLC tissues and cell lines. Overexpression of miR-143 suppressed NSCLC cell proliferation, induced apoptosis, and inhibited migration and invasion in vitro. Integrated analysis identified LIM domain kinase 1 (Limk1) as a direct and functional target of miR-143. Overexpression of Limk1 attenuated the tumor suppressive effects of miR-143 in NSCLC cells. Moreover, miR-143 was inversely correlated with Limk1 expression in NSCLC tissues. Together, our results highlight the significance of miR-143 and Limk1 in the development and progression of NSCLC.

miR-96/HBP1/Wnt/β-catenin regulatory circuitry promotes glioma growth

We found that miR-96 is overexpressed in glioma, and its level inversely correlates with the survival of patients. The reduction in miR-96 abundance suppresses the proliferation and colony formation of glioma cells. The tumorigenicity of U-87 MG cells is reduced by miR-96 silencing. miR-96 contributes to the activation of Wnt/β-catenin pathway in glioma cells. HMG-box transcription factor 1 (HBP-1), a Wnt/β-catenin pathway inhibitor, is suppressed by miR-96. The reactivation of Wnt/β-catenin signaling causes an increase in the proliferation of glioma cells, and a decrease in miR-96 expression. On the other hand, HBP1 silencing promotes miR-96 expression. Collectively, miR-96 contributes to the progression of glioma by enhancing the activation of the Wnt/β-catenin pathway, and the miR-96/HBP1/Wnt/β-catenin regulatory circuitry promotes the proliferation of glioma cells.