MiRNA-15a mediates cell cycle arrest and potentiates apoptosis in breast cancer cells by targeting synuclein-γ

Correlation of PTEN signaling pathway and miRNA in breast cancer

Breast cancer (BC) is one of the most common cancers among women and can be fatal if not diagnosed and treated on time. Various genetic and environmental factors play a significant role in the development and progression of BC. Within the body, different signaling pathways have been identified that contribute to cancer progression, or conversely, cancer prevention. Phosphatase and tensin homolog (PTEN) is one of the proteins that prevent cancer by inhibiting the oncogenic PI3K/Akt/mTOR signaling pathway. MicroRNAs (miRNAs) are molecules with about 18 to 28 base pairs, which regulate about 30% of human genes after transcription. miRNAs play a key role in the progression or prevention of cancer through different signaling pathway and mechanisms, e.g., apoptosis, angiogenesis, and proliferation. miRNAs, which are upstream mediators of PTEN, can reinforce or suppress the effect of PTEN signaling on BC cells, and suppressing the PTEN signaling, linked to weakness of the cancer cells to chemotherapeutic drugs. However, the precise mechanism and function of miRNAs on PTEN in BC are not yet fully understood. Therefore, in the present study, has been focused on miRNAs regulating PTEN function in BC.

The Herbal Combination Shu Gan Jie Yu Regulates the SNCG/ER-a/AKT-ERK Pathway in DMBA-Induced Breast Cancer and Breast Cancer Cell Lines Based on RNA-Seq and IPA Analysis

BACKGROUND

Soothing the liver (called Shu Gan Jie Yu in Chinese, SGJY) is a significant therapeutic method for breast cancer in TCM. In this study, 3 liver-soothing herbs, including Cyperus rotundus L., Citrus medica L. var. sarcodactylis Swingle and Rosa rugosa Thunb. were selected and combined to form a SGJY herbal combinatory.

THE AIM OF THE STUDY

To investigate the inhibiting effect of SGJY on breast cancer in vivo and vitro, and to explore the potential mechanisms.

MATERIALS AND METHODS

SGJY herbal combination was extracted using water. A breast cancer rat model was developed by chemical DMBA by gavage, then treated with SGJY for 11 weeks. The tumor tissue was preserved for RNA sequencing and analyzed by IPA software. The inhibition effects of SGJY on MCF-7 and T47D breast cancer cells were investigated by SRB assay and cell apoptosis analysis, and the protein expression levels of SNCG, ER-α, p-AKT and p-ERK were measured by western blotting.

RESULTS

SGJY significantly reduced the tumor weight and volume, and the level of estradiol in serum. The results of IPA analysis reveal SGJY upregulated 7 canonical pathways and downregulated 16 canonical pathways. Estrogen receptor signaling was the key canonical pathway with 9 genes downregulated. The results of upstream regulator analysis reveal beta-estradiol was the central target; the upstream regulator network scheme showed that 86 genes could affect the expression of the beta-estradiol, including SNCG, CCL21 and MB. Additionally, SGJY was verified to significantly alter the expression of SNCG mRNA, CCL21 mRNA and MB mRNA which was consistent with the data of RNA-Seq. The inhibition effects of SGJY exhibited a dose-dependent response. The apoptosis rates of MCF7 and T47D cells were upregulated. The protein expression of SNCG, ER-α, p-AKT and p-ERK were all significantly decreased by SGJY on MCF-7 and T47D cells.

CONCLUSION

The results demonstrate that SGJY may inhibit the growth of breast cancer. The mechanism might involve downregulating the level of serum estradiol, and suppressing the protein expression in the SNCG/ER-α/AKT-ERK pathway.

MicroRNA-146a-5p induces cell cycle arrest and enhances apoptosis in gastric cancer via targeting CDC14A

Objective: The present study was designed to investigate the expression of miRNA-146a-5p in gastric cancer (GC) tissues and the paired nonmalignant counterparts, to explore the influences of miRNA-146a-5p on the cell biological behavior of MKN-28 cells (highly metastatic human gastric cancer cells), and to identify the function of abnormal expression of its target gene cell division cycle 14 homolog A (CDC14A) in GC. Methods: We detected the expression of miRNA-146a-5p in formalin-fixed and paraffin-embedded (FFPE) GC tissues through microarray and quantitative real-time polymerase chain reaction (qRT-PCR). Then, we employed cell counting kit-8 (CCK-8) assays, cell cycle assays, and apoptosis analysis to uncover the latent function of miRNA-146a-5p in MKN-28 human GC cells. We also validated the target of miRNA-146a-5p via luciferase reporter assays. Results: miRNA-146a-5p levels were examined in the majority of primary GC tissues and several GC cell lines. As a result, miRNA-146a-5p levels were significantly declined in the GC tissues and cells. In addition, miRNA-146a-5p demonstrated a straight act on its 3'-untranslated region (3'-UTR) of CDC14A mRNA, accordingly decreasing the contents of CDC14A mRNA as well as its protein expression. An inverse correlation between CDC14A and miRNA-146a-5p was observed. Conclusion: The data suggest miRNA-146a-5p may contribute to inducing cell cycle arrest as well as prompting GC cell apoptosis via directly targeting CDC14A. Therefore, miRNA-146a-5p may be a potential indicator of the occurrence and development of GC.

Expression of lncRNAs AK058003 and APOC1P1 in breast cancer patients

In the current study, the expression levels of two important lncRNAs, i.e., AK058003 and APOC1P1, in breast tumors were compared with adjacent non-tumor tissues to evaluate their diagnostic potential in a panel of 121 patients. Total RNA was extracted, cDNA was synthesized and expression of AK058003 and APOC1P1 was assessed using qRT-PCR. A significant overexpression and positive correlation between these two lncRNAs were observed in tumor tissues compared to marginal healthy tissues. In conclusion, the examined lncRNAs were overexpressed in tumor tissues, suggesting their significant diagnostic value in breast cancer.

Pro- and anti-apoptotic microRNAs are differentially regulated during estivation in Xenopus laevis

Xenopus laevis, the African clawed frog, undergoes seasonal estivation to survive periods of drought when its lake-bed habitats dry up. The frog can lose ∼30% of its total body water, leading to conditions of impaired blood flow and ischemia which risk cellular survival under these harsh conditions. MicroRNAs are short, noncoding, single-stranded RNAs 21-24 nt long that have been widely implicated in hypometabolic responses, and serve functions including apoptosis survival. The levels of three pro-apoptotic and four anti-apoptotic miRNAs were measured in liver and skeletal muscle of estivating X. laevis, and bioinformatic analysis was performed to verify potential mRNA targets of these miRNAs. Members of pro-apoptotic miRNAs miR-15a, miR-16, and miR-101 showed upregulation as a result of dehydration stress, while anti-apoptotic miRNAs miR-19b, miR-21, miR-92a, and miR-155 showed differential regulation between the two tissues. Together, these miRNAs act in a more diverse fashion than arbitrarily pro- or anti-apoptotic, and encompass functions ranging from the inhibition of cell proliferation through cell cycle arrest to the prevention of skeletal muscle atrophy.

Construction of miRNA-mRNA Regulatory Network and Prognostic Signature in Endometrial Cancer

Introduction

This bioinformatic study confirmed a new miRNA-mRNA regulatory network and a prognostic signature in endometrial cancer (EC).

Materials and Methods

We downloaded RNA-seq and miRNA-seq data of EC from the TCGA database, then used EdegR package to screen differentially expressed miRNAs and mRNAs (DE-miRNAs and DE-mRNAs). Then, we constructed a regulatory network of EC-associated miRNAs and hub genes by Cytoscape, and determined the expression of unexplored miRNAs in EC tissues and normal adjacent tissues by quantitative Real-Time PCR (qRT-PCR). A prognostic signature model and a predictive nomogram were constructed. Finally, we explored the association between the prognostic model and the immune cell infiltration.

Results

A total of 11,531 DE-mRNAs and 236 DE-miRNAs, as well as 275 and 118 candidate DEGs for upregulated and downregulated DE-miRNAs were screened out. The miRNA-mRNA network included 5 downregulated and 13 upregulated DE-miRNAs. qRT-PCR proved that the expression levels of miRNA-18a-5p, miRNA-18b-5p, miRNA-449c-5p and miRNA-1224-5p and their target genes (NR3C1, CTGF, MYC, and TNS1) were consistent with our predictions. Univariate and multivariate Cox proportional hazards regression analyses of the hub genes revealed a significant prognostic value of NR3C1, EZH2, AND GATA4, and these genes were closely related to eight types of immune infiltration cells.

Conclusion

We identified three genes as candidate biomarkers for EC, which may provide a theoretical basis for targeted therapy.

The role of tumor suppressor short non-coding RNAs on breast cancer

Characterized by remarkable levels of aggression and malignancy, BC remains one of the leading causes of death in females world wide. Accordingly, significant efforts have been made to develop early diagnostic tools, increase treatment efficacy, and improve patient prognosis. Hopefully, many of the molecular mechanisms underlying BC have been detected and show promising targeting potential. In particular, short and long non-coding RNAs (ncRNAs) are a class of endogenous BC controllers and include a number of different species including microRNAs, Piwi-interacting RNAs, small nucleolar RNA, short interfering RNAs, and tRNA-derivatives. In this review, we discuss the tumor suppressing roles of ncRNAs in the context of BC, and the mechanisms by which ncRNAs target tumor hallmarks, including apoptosis, proliferation, invasion, metastasis, epithelial-mesenchymal transition, angiogenesis, and cell cycle progression, in addition to their diagnostic and prognostic significance in cancer treatment.

SOI-Nanowire Biosensor for the Detection of Glioma-Associated miRNAs in Plasma

Herein, we report the development of a highly sensitive nanotechnology-based system—silicon-on-insulator nanowire biosensor for the revelation of microRNAs (miRNAs), associated with the development of glioma in the human. In this system, a sensor chip, bearing an array of silicon nanowire structures, is employed. The sensor chip is fabricated using a top-down technology. In our experiments reported herein, we demonstrated the detection of DNA oligonucleotide (oDNA), which represents a synthetic analogue of microRNA-363 associated with the development of glioma. To provide biospecific detection of the target oligonucleotides, the surface of the nanowire structures is modified with oligonucleotide probes; the latter are complementary to the target ones. The concentration limit of the target oligonucleotide detection, attained using our nanowire biosensor, is at the level of DL~10−17 M. The revelation of the elevated level of glioma-associated miRNA in plasma is also demonstrated.

Evaluation of MiR-1908-3p as a novel serum biomarker for breast cancer and analysis its oncogenic function and target genes

Background

Breast cancer is one of the most common tumors for women globally. Various miRNAs have been reported to play a crucial role in breast cancer, however the clinical significance of miR-1908-3p in breast cancer remains unclear. The present study aimed to explore the role of miR-1908-3p in breast cancer.

Methods

The expression of miR-1908-3p was detected in 50 pairs of breast cancer tissues and adjacent normal tissues, 60 breast cancer patient serum and 60 healthy volunteer serum. The functional roles of miR-1908-3p in breast cancer cells such as proliferation, migration and invasion were evaluated using CCK8, SRB, wound healing and transwell chambers. In addition, bioinformatics tools were used to identify potential targets of miR-1908-3p.

Results

The results showed that the expression of miR-1908-3p were increased in breast cancer tissues and serum compared with normal breast tissues and serum of healthy volunteers respectively. Furthermore, the young breast cancer patients and HER2-positive patients had a higher level of tissues’ miR-1908-3p than elder breast cancer patients and HER2-negative patients, respectively. The young breast cancer patients had a higher level of serum miR-1908-3p than elder breast cancer patients, ROC analysis suggested that miR-1908-3p had the potential as a promising serum diagnostic biomarker of breast cancer. Up-regulation of miR-1908-3p promoted the cells proliferation, migration and invasion while knockdown of miR-1908-3p inhibited these processes in breast cancer cell MCF-7 and MDA-MB-231. The potential target genes of miR-1908-3p in breast cancer included ID4, LTBP4, GPM6B, RGMA, EFCAB1, ALX4, OSR1 and PPARA. Higher expression of these eight genes correlated with a better prognosis for breast cancer patients.

Conclusions

These results suggest that miR-1908-3p may exert its oncogenic functions via suppression of these eight genes in breast cancer.

Therapeutic effects of oligo-single-stranded DNA mimicking of hsa-miR-15a-5p on multiple myeloma

Despite the fact that a few novel agents improve the outcome of patients, MM remains incurable. Hence, developing a novel treatment strategy may prove to be promising for the clinical management of MM. Noncoding small RNAs, a cluster of RNAs that do not encode functional proteins, have been underlined that play a pivotal role in the pathogenesis of MM. Our previous study indicated that miR-15a acted as a tumor suppressor, which inhibited the cell proliferation and promoted the apoptosis of MM cells. The level of miR-15a was downregulated in MM cells and correlated with inferior outcome of MM patients. In the present study, we first developed an oligo-single-stranded DNA mimicking the sequence of hsa-miR-15a-5p (OMM-15a) and modified with locked nucleic acid (LNA-15a) to evaluate its anti-MM effects. Our results indicated that the LNA-15a presented an exciting anti-MM effect that showed notable cell growth suppression and apoptosis promotion in MM and other cancer cell lines through downregulating the expression level of target genes BCL-2, VEGF-A, and PHF19. Moreover, LNA-15a treatment significantly improved the anti-MM activity of bortezomib with the synergism effect in OCI-My5 MM cells. In our in vivo study, LNA-15a treatment significantly suppressed the tumor growth, and prolonged the survival of mice compared with the control group. However, our results indicated that the native form of oligo-single-stranded DNA mimic of hsa-miR-15a-5p (OMM-15a) without any modification had no effective inhibition on cell growth, even after increasing the dosage of OMM-15a in the treatment. Altogether, our finding provides the preclinical rationale to support the oligo-single-stranded DNA mimic of hsa-miR-15a with LNA modification, which is a promising tool for the therapy of both MM and other tumors with miR-15a downregulation.

Aberrant expression and mechanism of miR-130b-3p/phosphatase and tensin homolog in nephroblastoma in children

Nephroblastoma is the most common renal tumor in children. Abnormal expression of microRNAs (miRs) has been reported to be involved in the progression of various types of cancers. However, the role and underlying mechanism of miR-130b-3p in nephroblastoma remains unknown. Therefore, the present study aimed to explore the role and possible mechanism of miR-130b-3p in nephroblastoma in children. The present study identified that miR-130b-3p was highly expressed in nephroblastoma tissues obtained from children with nephroblastoma. To better understand the functions and the molecular mechanisms of miR-130b-3p in nephroblastoma, TargetScan was used to identify the potential targets of miR-130b-3p. Phosphatase and tensin homolog (PTEN), was identified as a target gene of miR-130b-3p, and it was observed to be downregulated in nephroblastoma. Further analysis indicated that miR-130b-3p inhibitor could significantly reduce cell proliferation, induce apoptosis and suppress the Akt/nuclear factor-κB/survivin signaling pathway in nephroblastoma cells. Notably, all these effects of miR-130b-3p on nephroblastoma cells were reversed by PTEN-small interfering RNA. In summary, the present study suggested that the miR-130b-3p/PTEN axis could serve a critical role in the progression and development of nephroblastoma. It also suggests that miR-130b-3p might be a valuable clinical biomarker and therapeutic target for nephroblastoma in children.

MiR-202-5p/PTEN mediates doxorubicin-resistance of breast cancer cells via PI3K/Akt signaling pathway

We intended to explore the effect of miR-202-5p and phosphatase and tensin homolog (PTEN) on doxorubicin (DOX) resistance of breast cancer cells. The result of quantitative reverse transcription-polymerase chain reaction (qRT-PCR) reveals that miR-202-5p was highly expressed in drug-resistant breast cancer tissues, while PTEN was expressed less. MiR-202-5p directly targeted PTEN. Further, it was found that the overexpression of miR-202-5p promoted the DOX resistance and proliferation as well as decreased apoptosis of MCF-7 cells. The lower expression of miR-202-5p inhibited DOX resistance and proliferation as well as increased the apoptosis of MCF-7/DOX cells. In vivo experiments showed that mice with downregulated miR-202-5p had smaller tumor volume and lower Ki67 level. The overexpression of PTEN declined the proliferation of MCF7 cells, while miR-202-5p's overexpression could offset the function of overexpression of PTEN. The knockdown of PTEN promoted MCF7/DOX cell proliferation that could be counteracted by miR-202-5p silence. Moreover, we also revealed that downregulated miR-202-5p expression inhibited PI3k/Akt signaling pathway-related protein by regulating expression of PTEN.

Construction of Potential Glioblastoma Multiforme-Related miRNA-mRNA Regulatory Network

Background: Glioblastoma multiforme (GBM), the most common and aggressive human malignant brain tumor, is notorious for its limited treatment options and poor prognosis. MicroRNAs (miRNAs) are found to be involved in tumorigenesis of GBM. However, a comprehensive miRNA-mRNA regulatory network has still not been established.

Methods: A miRNA microarray dataset (GSE90603) was obtained from GEO database. Then, we employed GEO2R tool to perform differential expression analysis. Potential transcription factors and target genes of screened differentially expressed miRNAs (DE-miRNAs) were predicted. The GBM mRNA dataset were downloaded from TCGA database for identifying differentially expressed genes (DEGs). Next, GO annotation and KEGG pathway enrichment analysis was conducted. PPI network was then established, and hub genes were identified via Cytoscape software. The expression and prognostic roles of hub genes was further evaluated.

Results: Total 33 DE-miRNAs, consisting of 10 upregulated DE-miRNAs and 23 downregulated DE-miRNAs, were screened. SP1 was predicted to potentially regulate most of screened DE-miRNAs. Three thousand and twenty seven and 3,879 predicted target genes were obtained for upregulated and downregulated DE-miRNAs, respectively. Subsequently, 1,715 upregulated DEGs and 1,259 downregulated DEGs were identified. Then, 149 and 295 potential downregulated and upregulated genes commonly appeared in target genes of DE-miRNAs and DEGs were selected for GO annotation and KEGG pathway enrichment analysis. The downregulated genes were significantly enriched in cGMP-PKG signaling pathway and calcium signaling pathway whereas the upregulated genes were enriched in pathways in cancer and PI3K-Akt signaling pathway. Construction and analysis of PPI network showed that STXBP1 and TP53 were recognized as hub genes with the highest connectivity degrees. Expression analytic result of the top 20 hub genes in GBM using GEPIA database was generally identical with previous differential expression analysis for TCGA data. EGFR, PPP3CB, and MYO5A expression was significantly associated with patients' OS.

Conclusions: In this study, we established a potential GBM-related miRNA-mRNA regulatory network, which explores a comprehensive understanding of the molecular mechanisms and provides key clues in seeking novel therapeutic targets for GBM. In the future, more experiments need to be performed to validate our current findings.

Long non-coding RNA AK058003, as a precursor of miR-15a, interacts with HuR to inhibit the expression of γ-synuclein in hepatocellular carcinoma cells

Long non-coding RNAs (lncRNAs) have been identified as critical players in multiple cancers and lncRNAs are tightly linked to cancer progression. However, only little amount of lncRNAs have been identified to participate in the molecular mechanisms of the progression of hepatocellular carcinoma. In this study, we found that lncRNA-AK058003 is down-regulated in hepatocellular carcinoma tissues and it is associated with the relapse and metastasis of the cancer. Furthermore, lncRNA-AK058003 acts as a tumor suppressor, suppressing hepatocellular carcinoma cell proliferation and metastasis in vitro and in vivo. lncRNA-AK058003 can reduce mRNA stabilizing protein HuR, which results in the inhibition of the expression of γ-synuclein. In addition, a bioinformatics study indicated that γ-synuclein is a target of miR-15a. To verify whether lncRNA-AK058003 plays a role in miR-15a-mediated inhibition of γ-synuclein, we demonstrated that lncRNA-AK058003 is very likely to be a precursor of miR-15a. Collectively, lncRNA-AK058003 can reduce the expression of mRNA stabilizing protein HuR and act as a precursor of miR-15a to suppress γ-synuclein-mediated cell proliferation and the metastasis of hepatocellular carcinoma.

MicroRNA expression patterns in human anterior cingulate and motor cortex: A study of dementia with Lewy bodies cases and controls

OVERVIEW

MicroRNAs (miRNAs) have been implicated in neurodegenerative diseases including Parkinson's disease and Alzheimer's disease (AD). Here, we evaluated the expression of miRNAs in anterior cingulate (AC; Brodmann area [BA] 24) and primary motor (MO; BA 4) cortical tissue from aged human brains in the University of Kentucky AD Center autopsy cohort, with a focus on dementia with Lewy bodies (DLB).

METHODS

RNA was isolated from gray matter of brain samples with pathology-defined DLB, AD, AD + DLB, and low-pathology controls, with n = 52 cases initially included (n  = 23 with DLB), all with low (<4 h) postmortem intervals. RNA was profiled using Exiqon miRNA microarrays. Quantitative PCR for post hoc replication was performed on separate cases (n = 6 controls) and included RNA isolated from gray matter of MO, AC, primary somatosensory (BA 3), and dorsolateral prefrontal (BA 9) cortical regions.

RESULTS

The miRNA expression patterns differed substantially according to anatomic location: of the relatively highly-expressed miRNAs, 150/481 (31%) showed expression that was different between AC versus MO (at p < .05 following correction for multiple comparisons), most (79%) with higher expression in MO. A subset of these results were confirmed in qPCR validation focusing on miR-7, miR-153, miR-133b, miR-137, and miR-34a. No significant variation in miRNA expression was detected in association with either neuropathology or sex after correction for multiple comparisons.

CONCLUSION

A subset of miRNAs (some previously associated with α-synucleinopathy and/or directly targeting α-synuclein mRNA) were differentially expressed in AC and MO, which may help explain why these brain regions show differences in vulnerability to Lewy body pathology.

Clinicopathological features associated to MiRNA-195 expression in patients with breast cancer: Evidence of a potential biomarker

BACKGROUND & OBJECTIVE

MiRNAs are a systematic class of small non-coding RNAs with impending role as tumor biomarkers. Our objective was to identify the level of expression of Mir-195 in patients with breast cancer along with its correlation with clinicopathologic features.

METHODS

A total of 209 females in which 139 histologically diagnosed breast cancer (BC) cases and 70 healthy controls matched for age, their relative clinical and histopathological findings were recorded from their laboratory reports and hospital record of the patients. Plasma was used for extraction of total RNA and cDNA was prepared by using both miR-195 stem loop RT primers and gene specific antisense primers while U6 IT was used as control. Quantitative real-time PCR (qRT-PCR) for miR-195 expression status was performed and amplification (down regulation) was recorded.

RESULTS

Of 139 samples the expression of miR-195 was down regulated in 72.6% cases and the remaining 27.3% cases behaved same as 70 healthy or normal controls. Significant correlation of low miR-195 expression with higher differentiation grade, lymph node metastasis and clinical stage was found.

CONCLUSION

Significant correlation between miR-195 expression and some clinicopathological features were recognized. MiR-195 could be used as potential non-invasive, molecular biomarker for early detection of breast cancer.

Downregulation of microRNA-15a suppresses the proliferation and invasion of renal cell carcinoma via direct targeting of eIF4E

The downregulation of microRNA-15a has been reported in several human tumors. However, its expression and functional importance in renal cell carcinoma (RCC) remain unknown. The aim of the present study was to investigate its expression, biological functions and underlying mechanisms in RCC tumorigenesis. The expression levels of miR-15a were examined by qRT-PCR in 40 RCC specimens and adjacent‑paired normal tissues. Cell Counting Kit-8 (CCK-8), colony formation, flow cytometry and Transwell assays were used to explore the potential influence of miR-15a transfection on RCC cell proliferation, the cell cycle, cell apoptosis, and cell invasion. Luciferase reporter assays were performed to confirm the potential target of miR-15a, in combination with qRT-PCR, western blotting and immunohistochemical assays. We found that miR-15a was significantly downregulated in most RCC specimens compared with adjacent normal tissues (P<0.01). Overexpression of miR-15a inhibited cellular growth, suppressed invasion and arrested cells at the G1/G0 phase, and induced cell apoptosis in RCC cells. Luciferase assays revealed that miR-15a directly targeted the binding site of the 3'-untranslated region (3'-UTR) of eIF4E, and inhibited its expression at both mRNA and protein levels. eIF4E expression was negatively associated with miR-15a expression in RCC tissues. eIF4E overexpression treatment partially abrogated the inhibitory effect of miR-15a on cell proliferation and invasion, as well as inactivated P13K/AKT/mTOR signaling in RCC cells. In conclusion, the present study indicated that miR-15a downregulation was associated with cell proliferation and invasion by directly targeting eIF4E during RCC progression. Thus, it may serve as a potential tumor suppressor and therapeutic target for the treatment of RCC.

microRNA-130a is an oncomir suppressing the expression of CRMP4 in gastric cancer

Gastric cancer is one of the most common causes of death worldwide, although its incidence has steadily declined in recent years. There is strong evidence that aberrantly expressed microRNAs (miRNAs) are involved in gastric cancer tumorigenesis. Furthermore, CRMP4 is closely associated with the occurrence and development of gastric cancer, and our predictions suggest that miR-130a, which can promote gastric cancer tumorigenesis, is a potential CRMP4 regulator. In this study, we investigated the expression of CRMP4 and miR-130a in human gastric cancer cell lines by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot (WB) examination and direct interactions between miR-130a and CRMP4 by dual-luciferase reporter assay. We also evaluated the biological roles of miR-130a and CRMP4 in gastric cancer cells by flow cytometry, MTT assay, soft agar colony formation assay, and Transwell tests and confirmed CRMP4 function in vivo, using a tumor xenograft model. Our results demonstrated that CRMP4 expression was significantly decreased at both the gene and protein levels, while miR-130a expression was notably increased, in five human gastric cancer cell lines compared with human gastric epithelial cells. Dual-luciferase reporter assays indicated that CRMP4 was the direct target of miR-130a. Moreover, an inverse regulatory relationship between miR-130a and CRMP4 was verified by qRT-PCR and WB, and overexpression of miR-130a in BGC823 cells enhanced apoptosis and cell proliferation, arrested the cell cycle in G0/G1, and facilitated cell colony formation, invasion, migration, and adhesion, while upregulation of CRMP4 had opposite effects. Finally, the growth and weight of transplanted tumors derived from BGC823 cells in which CRMP4 was knocked down were remarkably reduced. These data indicate that miR-130a is an oncomir targeting CRMP4 and could be developed as a potential prognostic factor and a novel therapeutic target in gastric cancer.

Serum microRNA-15a level acts as a potential diagnostic and prognostic biomarker for human esophageal squamous cell carcinoma

BACKGROUND

Clinical significance of microRNA (miR)-15a in human esophageal squamous cell carcinoma (ESCC) remains unclear.

OBJECTIVE

To evaluate the expression level of miR-15a and to determine its potential for diagnosis and prognosis in ESCC.

METHODS

Quantitative reverse transcription polymerase chain reaction was performed to examine the expression levels of miR-15a in ESCC tissues and patients' sera. The diagnostic and prognostic implications of serum miR-15a level in human ESCC were further evaluated.

RESULTS

Expression levels of miR-15a in ESCC tissues and patients' sera were significantly decreased (both P< 0.001). Additionally, serum miR-15a had an optimal diagnostic cut-off point (2.29) for ESCC with sensitivity of 86.36% and specificity of 100.00%. Moreover, low serum miR-15a level more frequently occurred in ESCC patients with advanced tumor-node-metastasis, T and N stages (all P= 0.01) and poor tumor differentiation (P= 0.03). The Kaplan-Meier curve showed that low miR-15a expression was significantly associated with shorter overall survival (OS) and disease-free survival (DFS) of ESCC patients (both P< 0.001). Further multivariate analysis identified miR-15a as an independent prognostic factor for both OS and DFS (both P= 0.01).

CONCLUSION

Decreased expression of miR-15a may play a crucial role in ESCC development and progression. Serum miR-15a level could be used as a potential diagnostic and prognostic marker in clinics.

MicroRNA-130b targets PTEN to mediate drug resistance and proliferation of breast cancer cells via the PI3K/Akt signaling pathway

Multidrug resistance (MDR) correlates with treatment failure and poor prognosis among breast cancer patients. This study was aimed to investigate the possible mechanism by which microRNA-130b-3p (miR-130b) mediates the chemoresistance and proliferation of breast cancer. MiR-130b was found to be up-regulated in tumor tissues versus adjacent tissues of breast cancer, as well as in adriamycin (ADR) resistant breast cancer cell line (MCF-7/ADR) versus its parental line (MCF-7) and the non-malignant breast epithelial cell line (MCF-10A), demonstrating its crucial relevance for breast cancer biology. We identified that PTEN was a direct target of miR-130b and inversely correlated with miR-130b expression in breast cancer. Moreover, over-expression of miR-130b promoted drug resistance, proliferation and decreased apoptosis of MCF-7 cells, while suppression of miR-130b enhanced drug cytotoxicity and apoptosis, as well as reduced proliferation of MCF-7/ADR cells in vitro and in vivo. Particularly, miR-130b mediated the activity of phosphoinositide-3 kinase (PI3K)/Akt signaling pathway as well as the chemoresistance and proliferation of breast cancer cell lines, which was partially blocked following knockdown of PTEN. Altogether, miR-130b targets PTEN to induce MDR, proliferation, and apoptosis via PI3K/Akt signaling pathway. This provides a novel promising candidate for breast cancer therapy.

miR‑15a‑5p acts as an oncogene in renal cell carcinoma

miRNAs have been reported to be involved in multiple cellular processes and the tumorigenesis of various cancers. miR‑15a‑5p (also termed miR‑15a) has previously been determined to be upregulated in renal cell carcinoma (RCC) by microarray profile. However, the expression and function of miR‑15a‑5p in RCC remain to be validated. In the present study, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was performed to detect the expression levels of miR‑15a‑5p in RCC tissues and cells. The expression level of miR‑15a‑5p was upregulated or downregulated by transfecting synthesized miR‑15a‑5p mimics or inhibitors. The MTT assay, CCK‑8 assay, Transwell assay, wound healing assay, Hoechest 33342 staining and flow cytometry were conducted to investigate the role of miR‑15a‑5p in RCC. The results of the RT‑qPCR demonstrated that miR‑15a‑5p was upregulated in RCC tissues and ACHN, 786‑O and 769P RCC cells compared with paired normal tissues and HEK‑293T cells. miR‑15a‑5p was observed to be associated with RCC cell proliferation, migration, invasion and apoptosis. The results demonstrated that miR‑15a‑5p may be important as a tumor promoter in RCC. To the best of our knowledge, the present study is the first to describe miR‑15a‑5p as a tumor promoter in RCC. Further research will be performed to investigate the underlying signaling pathway of miR‑15a‑5p and the potential role of miR‑15a‑5p as a biomarker for early detection, prognosis prediction and a therapeutic target of RCC.

Downregulation of microRNA-497 is associated with upregulation of synuclein γ in patients with osteosarcoma

The present study aimed to investigate the effects of microRNA (miRNA/miR)-497 expression levels on the expression levels of synuclein γ (SNCG) in serum samples, as well as osteosarcoma and lung-metastatic tissue samples, from patients with osteosarcoma. Between December 2010 and August 2013, fasting peripheral blood was collected from 36 patients with osteosarcoma for serum separation. In addition, osteosarcoma and lung metastatic tissues were resected from 15 osteosarcoma patients with lung metastasis by surgery. Bioinformatics was employed to predict the amount miRNA that binds to SNCG. Reverse transcription-quantitative polymerase chain reaction was used to determine the expression levels of SNCG and miR-497, and western blotting was performed to determine protein expression levels. It was observed that SNCG mRNA and protein expression levels were significantly upregulated in osteosarcoma tissues (P<0.01). Additionally, SNCG mRNA (P<0.01) and protein (P<0.05) expression levels were significantly upregulated in the blood of patients with osteosarcoma. SNCG mRNA and protein expression levels were also significantly upregulated in lung metastatic tissues (P<0.01). miR-497 was significantly downregulated in all three samples; therefore downregulation of miR-497 may lead to the occurrence, development and metastasis of osteosarcoma through the upregulation of SNCG mRNA. In summary, the upregulation of SNCG in blood, osteosarcoma tissue and lung metastatic tissue samples is associated with the dowregulation of miR-497, suggesting that miR-497 may be a potential marker and therapeutic target for the treatment of osteosarcoma.

MicroRNA-15a inhibits the growth and invasiveness of malignant melanoma and directly targets on CDCA4 gene

MicroRNAs can affect behaviors of tumor cells by modulating the expression of the target genes that involve tumor growth, invasiveness, and death. The goal of this research is to examine the effects of miR-15a on the proliferation and invasiveness of malignant melanoma cells in vitro, as well as the therapeutic effect of miR-15a in a mouse melanoma model. miR-15a displayed inhibitory effects on proliferation and invasiveness of several malignant melanoma cell lines. miR-15a also caused cell cycle arrest at G1/G0 phase. miRNA 15a downregulated the expressions of CDCA4 and AKT-3 in melanoma cell lines. In vivo, experiment showed that miRNA 15a significantly retarded the growth of melanoma tumors in the mouse model. The luciferase reporter assay demonstrated that miR15a can suppress gene expression through the binding site in the 3 'UTR of CACD4, which is a bona fide target of miRNA 15a. In conclusion, miRNA 15a suppressed the growth and invasiveness of melanoma cells, suggesting that miRNA 15a may represent a viable microRNA-based therapy against melanoma.

MicroRNA-490 inhibits tumorigenesis and progression in breast cancer

MicroRNAs are consistently reported to regulate gene expression in all cancer cell types by modulating a wide range of biological processes, including cell proliferation, differentiation, and apoptosis, which are associated with tumor development and progression. Previous studies have revealed that miR-490-3p regulates cell proliferation and apoptosis in cancers, such as hepatocellular carcinoma, lung cancer, bladder cancer, and ovarian carcinoma. In this study, we explored the hitherto unrevealed role of miR-490-3p in breast cancer. We tested miR-490-3p expression in breast cancer tissue and paracarcinoma tissue using reverse transcription-polymerase chain reaction. We also transfected the human breast cancer cell lines MCF-7 and T47D with miR-490-3p; subsequently, we determined the cell phenotype and the expression of Ras homolog gene family member A (RhoA), Bcl-xL, matrix metalloproteinase-9, and P70S6K (P70S6 kinase). Dual-luciferase reporter assay and a xenograft mouse model were used to reveal the roles of miR-490-3p and its target gene RHOA. We found that the levels of miR-490-3p were lower in the breast cancer tissue than in the paracarcinoma tissues. The overexpression of miR-490-3p suppressed breast cancer cell proliferation and promoted early stage apoptosis. Western blotting results revealed that the miR-490-3p overexpression reduced RhoA, Bcl-XL, matrix metalloproteinase-9, and P70S6K protein expression. The dual-luciferase reporter assay confirmed that RhoA is a target of miR-490-3p. The xenograft mouse model confirmed that miR-490-3p overexpression suppressed tumor growth and reduced RhoA expression. Our results indicate that miR-490-3p acts as oncosuppressive microRNA to inhibit breast cancer tumorigenesis and progression by targeting RhoA directly. It may contribute to breast cancer diagnosis and treatment.

miR‑365 overexpression promotes cell proliferation and invasion by targeting ADAMTS-1 in breast cancer

MicroRNAs (miRNAs) have important roles in the initiation and progression of human cancer, including breast cancer. We evaluated miR‑365 expression in breast cancer tissues, and investigated its effects on cell growth, cell cycle, cell invasion, and expression of its target gene ADAMTS-1. miR‑365 expression levels were analyzed in breast cancer tissues and adjacent normal tissues using qRT-PCR. CCK-8, cell cycle, and invasion assays were used to explore the role of miR‑365 expression in breast cancer cells. We conducted luciferase reporter and western blot assays to test whether ADAMTS-1 is a direct target of miR‑365. We found that miR‑365 expression levels were significantly higher in breast cancer tissues compared with adjacent non-tumor tissues (P<0.05). These relatively high expression levels were significantly associated with advanced clinical stages (P<0.05). In breast cancer cell lines, transfection with miR‑365 inhibitor suppressed proliferation and invasion, and resulted in cell cycle arrest. Subsequent experiments indicated that miR‑365 bound the 3'-UTR of ADAMTS-1 and downregulated its expression. Our findings indicated that the inhibition of miR‑365 reduced cell proliferation and cell invasion. Additionally, miR‑365 may function as a novel oncogene in breast cancer through targeting ADAMTS-1. These findings provide insight into the mechanism of breast cancer pathogenesis.

MiR-492 contributes to cell proliferation and cell cycle of human breast cancer cells by suppressing SOX7 expression

MicroRNAs (miRNAs) have emerged as important regulators that potentially play critical roles in cancer cell biological processes. Previous studies have shown that miR-492 plays an important role in cell tumorigenesis in multiple kinds of human cancer cells. However, the underlying mechanisms of this microRNA in breast cancer remain largely unknown. In the present study, we investigated miR-492's role in cell proliferation of breast cancer. MiR-492 expression was markedly upregulated in breast cancer tissues and breast cancer cells. Overexpression of miR-492 promoted the proliferation and anchorage-independent growth of breast cancer cells. Bioinformatics analysis further revealed sex-determining region Y-box 7 (SOX7), a putative tumor suppressor, as a potential target of miR-492. Data from luciferase reporter assays showed that miR-492 directly binds to the 3'-untranslated region (3'-UTR) of SOX7 messenger RNA (mRNA) and repressed expression at both transcriptional and translational levels. Ectopic expression of miR-492 led to downregulation of SOX7 protein, which resulted in the upregulation of cyclin D1 and c-Myc. In functional assays, SOX7 silenced in miR-492-in-transfected ZR-75-30 cells has positive effect to promote cell proliferation, suggesting that direct SOX7 downregulation is required for miR-492-induced cell proliferation and cell cycle of breast cancer. In sum, these results suggest that miR-492 represents a potential onco-miR and participates in breast cancer carcinogenesis by suppressing SOX7 expression.