Target Of miR-200c Research Articles

MicroRNA-34c-3p target inhibiting NOTCH1 suppresses chemosensitivity and metastasis of non-small cell lung cancer.

BackgroundChemotherapy is the standard treatment for non-small cell lung cancer (NSCLC). However, chemoresistance frequently occurs, making the treatment of NSCLC more difficult.MethodWe combined clinical and experimental studies to establish the role of microRNA (miR)-34c in NSCLC metastasis and chemoresistance.ResultsMiR-34c expression was significantly decreased in patients with NSCLC who showed a poor chemoresponse and metastasis. Overexpression of miR-34c sensitized NSCLC cells to paclitaxel and cisplatin both in vitro and in vivo. Furthermore, we found that NOTCH1 was target of miR-34c in NSCLC cells and played a key role in the effects of miR-34c on NSCLC.ConclusionNSCLC metastasis and chemoresistance are suppressed though the miR-34c/NOTCH1 axis. MiR-34c has important implications in the development of therapeutic strategies for metastasis and chemoresistance in NSCLC.

A Network-Based Approach for Identification of Subtype-Specific Master Regulators in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC), the predominant subtype of pancreatic cancer, has been reported with equal mortality and incidence for decades. The lethality of PDAC is largely due to its late presentation, when surgical resection is no longer an option. Similar to other major malignancies, it is now clear that PDAC is not a single disease, posing a great challenge to precise selection of patients for optimized adjuvant therapy. A representative study found that PDAC comprises four distinct molecular subtypes: squamous, pancreatic progenitor, immunogenic, and aberrantly differentiated endocrine exocrine (ADEX). However, little is known about the molecular mechanisms underlying specific PDAC subtypes, hampering the design of novel targeted agents. In this study we performed network inference that integrates miRNA expression and gene expression profiles to dissect the miRNA regulatory mechanism specific to the most aggressive squamous subtype of PDAC. Master regulatory analysis revealed that the particular subtype of PDAC is predominantly influenced by miR-29c and miR-192. Further integrative analysis found miR-29c target genes LOXL2, ADAM12 and SERPINH1, which all showed strong association with prognosis. Furthermore, we have preliminarily revealed that the PDAC cell lines with high expression of these miRNA target genes showed significantly lower sensitivities to multiple anti-tumor drugs. Together, our integrative analysis elucidated the squamous subtype-specific regulatory mechanism, and identified master regulatory miRNAs and their downstream genes, which are potential prognostic and predictive biomarkers.

Cross-talk between miR-29c and transforming growth factor-β3 is mediated by an epigenetic mechanism in leiomyoma

To determine the expression of miR-29c and its target gene transforming growth factor-β3 (TGF-β3) in leiomyoma and the mechanisms of their reciprocal regulation. Experimental study. Academic research laboratory. Women undergoing hysterectomy for leiomyoma. Overexpression and underexpression of miR-29c; blockade of DNA methyltransferase 1 (DNMT1). The miR-29c and its target gene TGF-β3 in leiomyoma and the effects of TGF-β3 and blockade of DNMT1 on miR-29c expression. Leiomyoma expressed significantly lower levels of miR-29c, but higher expression of TGF-β3 compared with matched myometrium. The expression of TGF-β3 and miR-29c were independent of race/ethnicity. Using 3' untranslated region luciferase reporter assay we confirmed that TGF-β3 is a direct target of miR-29c in leiomyoma smooth muscle cells (LSMCs). Gain-of-function of miR-29c in LSMCs inhibited the expression of TGF-β3 at protein and messenger RNA levels, whereas loss-of-function of miR-29c had the opposite effect. Treatment of LSMCs with TGF-β3 inhibited the expression of miR-29c, whereas it stimulated DNMT1 expression. Knockdown of DNMT1 through transfection with small interfering RNA significantly decreased the expression of TGF-β3, and induced miR-29c expression. Knockdown of DNMT1 also attenuated the inhibitory effect of TGF-β3 on miR-29c expression. Furthermore, we demonstrated that TGF-β3 increased the methylation level of miR-29c promoter in LSMCs. There is an inverse relationship in the expression of TGF-β3 and miR-29c in leiomyoma. The TGF-β3 is a direct target of miR-29c and inhibits the expression of miR-29c through an epigenetic mechanism. The cross-talk between miR-29c and TGF-β3 provides a feed forward mechanism of fibrosis in leiomyoma.

Circ_016719 plays a critical role in neuron cell apoptosis induced by I/R via targeting miR-29c/Map2k6

BackgroundStroke is a leading cause of mortality worldwide. Rac-MAPK kinase 6 (Map2k6) plays important roles in cell proliferation and apoptosis. However, the role played by Map2k6 in stroke injury and the underlying mechanism of action remain unknown. MethodsMice received cerebral ischemia/reperfusion (I/R) injuries by transient middle cerebral artery occlusion. HT22 cells were subjected to oxygen glucose deprivation and reoxygenation (OGD/R) to simulate an I/R injury. Subsequently, the levels of circ_016719, miR-29c and Map2k6 expression were determined, and their interactions were examined by luciferase assays. Circ_016719 knockdown, miR-29c inhibition or Map2k6 overexpression was induced in HT22 cells; after which, the cells were examined for their viability, apoptosis, autophagy and proliferation, as well their levels of Map2k6, p38, p53, LC3B–I, LC3B-II, Beclin 1, and p62 expression. ResultsSignificantly increased levels of circ_016719 and Map2k6, and decreased levels of miR-29c were observed in both in vivo and in vitro I/R injury models. In HT22 cells, circ_016719 knockdown significantly increased miR-29c expression and cell proliferation, but decreased Map2k6 expression and cell apoptosis. Additionally, significant increases in LC3B–I and p62 levels and decreased LC3B-II levels were observed, indicating that circ_016719 knockdown had significantly inhibited autophagy. Furthermore, additional inhibition of miR-29c markedly suppressed the effects of circ_016719 knockdown; however, that suppression was significantly attenuated by Map2k6 overexpression. Additionally, Map2k6 was identified as a direct target of miR-29c, which in turn, might be sponged by circ_016719. ConclusionsOur results suggest that circ_016719 directly targets miR-29c, and thereby regulates the expression and functions of Map2k6, which significantly contributes to the pro-apoptotic role of circ_016719.

Long noncoding RNA LINC02582 acts downstream of miR-200c to promote radioresistance through CHK1 in breast cancer cells

Radiotherapy is essential to treat breast cancer and microRNA (miRNA) miR-200c is considered as a radiosensitizer of breast cancer. However, the molecular mechanisms by which miR-200c regulates radiosensitivity remain largely unknown. In the present study, we showed that induction of miR-200c led to widespread alteration in long noncoding RNA (lncRNA) expression in breast cancer cells. We identified lncRNA LINC02582 as a target of miR-200c. Inhibition of LINC02582 expression increased radiosensitvity, while overexpression of LINC02582 promoted radioresistance. Mechanistically, LINC02582 interacts with deubiquitinating enzyme ubiquitin specific peptidase 7 (USP7) to deubiquitinate and stabilize checkpoint kinase 1 (CHK1), a critical effector kinase in DNA damage response, thus promoting radioresistance. Furthermore, we detected an inverse correlation between the expression of miR-200c vs. LINC02582 and CHK1 in breast cancer samples. These findings identified LINC02582 as a downstream target of miR-200c linking miR-200c to CHK1, in which miR-200c increases radiosensitivity by downregulation of CHK1.

MiR-29c suppresses cell invasion and migration by directly targeting CDK6 in gastric carcinoma.

Gastric carcinoma (GC) is one common malignant tumor with high morbidity and mortality rates all over the world. Recently, numerous studies have showed that the microRNAs (miRNAs) dysregulation was implicated in GC carcinogenesis. This research aimed to explore the potential associations between miR-29c and cyclin-dependent kinase 6 (CDK6) in GC. GC tissues and corresponding normal tissues were collected from 54 GC patients who underwent surgery at the Second Hospital of Anhui Medical University between 2015 and 2017. We measured the expressions of CDK6 and miR-29c in GC tissues using quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). We next investigated the functions of miR-29c in GC cells by performing transwell assays. To further determine the correlation between miR-29c and CDK6 in GC cell invasion and migration, the rescue experiments were performed by co-transfecting miR-29c inhibitor and CDK6 siRNA into AGS cells. MiR-29c expressions were significantly declined in GC tissues and cells. Additionally, functional assays showed that the miR-29c over-expression suppressed the invasion and migration capacities of GC cells. According to TargetScan and dual-luciferase reporter assays, CDK6 was identified as a new miR-29c target. Moreover, the knockout of CDK6 had similar effects as the miR-29c over-expression in GC cells. The current research indicated that miR-29c over-expression could inhibit tumor behaviors in GC partially via down-regulating CDK6. We revealed that miR-29c down-regulated in GC tissues and cells. MiR-29c over-expression effectively suppressed the GC cell invasion and migration. Moreover, CDK6 was identified as a direct functional target of miR-29c in GC. The current study provides new insights for the GC treatment and suggests that miR-29c/CDK6 axis is a therapeutic candidate target for GC patients.

MicroRNA-200b and microRNA-200c are up-regulated in PCOS granulosa cell and inhibit KGN cell proliferation via targeting PTEN

BackgroundPolycystic ovary syndrome (PCOS) is one of the most common endocrine metabolic disorders characterized by hyperandrogenism, polycystic ovaries and ovulatory dysfunction. Several studies have reported that the aberrant expression of miRNAs contributes a lot to disordered folliculogenesis in PCOS, though the role and underlying mechanism of microRNA-200b (miR-200b) and microRNA-200c (miR-200c) in the development of PCOS remain unclear.MethodsThe expression of miR-200b in granulosa cells (GCs) derived from 90 PCOS patients and 70 controls was analyzed by using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Granulosa-like tumor cell line (KGN) was cultured for cell counting kit-8 (CCK-8) assays after over-expression of miR-200b, miR-200c or knockdown phosphatase and tensin homolog (PTEN). TargetScan was used to identify the potential targets of miR-200b and miR-200c, which was further verified by qRT-PCR, western blot and luciferase assays.ResultsSignificantly increased expression of miR-200b was observed in PCOS patients compared with the controls. Moreover, over-expression of miR-200b and miR-200c inhibited the proliferation of KGN cells. In addition, our results verified that miR-200b and miR-200c directly targeted PTEN, knockdown of which suppressed KGN cells proliferation.ConclusionOur findings demonstrate that miR-200b and miR-200c suppress the proliferation of KGN cells by targeting PTEN, and this might provide new evidence for abnormal proliferation of GCs in PCOS.

Restoration of microRNA-29c in type I endometrioid cancer reduced endometrial cancer cell growth.

Endometrial cancer is the most common gynaecological cancer worldwide, and the prognosis of patients with advanced disease remains poor. MicroRNAs (miRs) are dysregulated in endometrial cancer. miRs-29-a, -b and -c expression levels are downregulated in endometrial cancer; however, a specific role for miR-29c and its target genes remain to be elucidated. The aim of the present study was to determine the functional effect of restoring miR-29c expression in endometrial cancer cell lines and to identify miR-29c targets involved in cancer progression. miR-29c expression in human endometrial tumour grades 1-3 and benign tissue as well as in the endometrial cancer cell lines Ishikawa, HEC1A and AN3CA were analysed using reverse transcriptase-quantitative PCR (RT-qPCR). The cell lines were transfected with miR-29c mimic, miR-29c inhibitor or scrambled control. xCELLigence real-time cell monitoring analysed proliferation and migration, and flow cytometry was used to analyse apoptosis and cell cycle. The expression of miR-29c target genes in transfected cell lines was analysed using RT-qPCR. miR-29c was downregulated in grade 1-3 endometrial cancer samples compared with benign endometrium. miR-29c was reduced in Ishikawa and AN3CA cells, but not in HEC1A cell lines compared with non-cancerous primary human endometrial epithelial cells. Overexpression of miR-29c variably reduced proliferation, increased apoptosis and reduced the expression levels of miR-29c target genes, including cell division cycle 42, HMG-box transcription factor 1, integrin subunit β 1, MCL1 apoptosis regulator BCL2 family member, MDM2 proto-oncogene, serum/glucocorticoid regulated kinase 1, sirtuin 1 and vascular endothelial growth factor A, across the three cell lines investigated. Inhibition of miR-29c in HEC1A cells increased proliferation and collagen type IV α 1 chain expression. The re-introduction of miR-29c to endometrial cancer cell lines reduced proliferation, increased apoptosis and reduced miR-29c target gene expression in vitro. The present results suggested that miR-29c may be a potential therapeutic target for endometrial cancer.

The effect of combined miR-200c replacement and cisplatin on apoptosis induction and inhibition of gastric cancer cell line migration.

One of the major obstacles in the treatment of cancer is resistance to standard chemotherapeutic drugs. According to the numerous reports, miR-200c is involved in many cancers, especially gastric cancer, and also miR-200c has been known as an effective factor in the elimination of chemotherapy resistance. The purpose of this study was to explore the potential function and mechanism of miR-200c and cisplatin in the inhibition of migration and induction of apoptosis in gastric cancer cells. In this study, first, miR-200c mimics and LNA-anti-miR-200c were transfected into KATOIII cells. Moreover, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay results revealed that increased miR-200c expression and cisplatin can more inhibited the proliferation of KATOIII cells. MiR-200c overexpression inhibited the movement of KATOIII cells in wound healing assay. Subsequently, miR-200c/cisplatin could suppress colony formation in KATOIII cells. To identify a potential miR-200c target, we investigated the effect of miR-200c modulation on RhoE, PTEN, VEGFR, and MMP9 expression levels. Increased miR-200c expression caused a reduction in VEGFR and MMP9 mRNA and protein, suggesting that VEGFR and MMP9 are targets of miR-200c. In addition, reverse-transcription polymerase chain reaction assays showed that RhoE is target gene of miR-200c and LNA-anti-miR-200c suppressed the expression of PTEN. Flow cytometry and 4',6-diamidino-2-phenylindole staining analysis indicated that miR-200c increased the cisplatin-induced apoptosis which may be associated with suppression of RhoE expression in KATOIII cells, also cell-cycle analysis showed the arrest of cell-cycle progression at the G2 phase. These data demonstrated that miR-200c functioned as a suppressor gene in KATOIII cells. Also, miR-200c can be a potential therapeutic approach to overcome chemoresistance during cisplatin chemotherapy.

The role of miR-29c/B7-H3/Th17 axis in children with Mycoplasma pneumoniae pneumonia

BackgroundMycoplasma pneumoniae (M. pneumoniae) is one of the most common causes of community-acquired pneumonia in children. Recent studies demonstrated that the incidence of severe or fatal M. pneumoniae was gradually increasing, which may be related to the excessive inflammation. However, the exact pathogenesis of excessive inflammation in Mycoplasma pneumoniae pneumonia(MPP) is still unclear. This study aimed to reveal the role of miR-29c/B7-H3/Th17 axis in children with MPP.MethodsChildren hospitalized in Respiratory Department during Jan. 2014 to Dec. 2015 were enrolled. All children enrolled was confirmed with MP infection using real-time PCR and ELISA. Children were excluded if they were co-infected with other pathogens. A total of 52 children with MPP and 26 controls were enrolled. miR-29c expression in monocytes of children with MPP was determined by real-time PCR and soluble B7-H3 (sB7-H3) and IL-17 were determined by ELISA, and explore their clinical significance. miR-29c overexpression and silencing technology and luciferase reporter assay were performed to confirm whether B7-H3 is the direct target of miR-29c. The levels of transcription factor ROR-γt in CD4+ T cells and cytokine IL-17A in supernatant were detected after stimulated by different concentrations of B7-H3 fusion protein in vitro.ResultsOf all 52 children with MPP, the mean age of the children were 77 ± 33 months, and 23 cases were male accounting for 44.2%. Nineteen cases had pleural effusion accounting for 36.5%. Children with MPP had significantly lower level of miR-29c and higher level of sB7-H3 and IL-17 compared to controls (both P < 0.05). The level of miR-29c significantly increased during convalescent phase compared to that of acute phase while sB7-H3 and IL-17 significantly decreased during convalescent phase (both P < 0.05). There was a positive correlation between the level of sB7-H3 and IL-17 in children with MPP during acute-stage (r = 0.361,P = 0.009). Children with MPP combined with pleural effusion had significantly higher level of sB7-H3 compared to those without pleural effusion (9952.3 ± 3065.3 vs. 7449.7 ± 2231.5, pg/ml), and the levels of sB7-H3 was positively correlated with the number of days of fever. The level of miR-29c was negatively correlated with M. pneumoniae specific IgG, IgM level. High concentrations of B7-H3(15μg/ml) could enhance ROR-γt expression and increase IL-17A. Functional studies based on luciferase reporter assay and immunofluorescence staining suggested that B7-H3 is the direct target of miR-29c, and miR-29c silencing or overexpression could up- or down-regulate the expression of B7-H3 in THP-1 cells.ConclusionsThe axis of miR-29c/B7-H3/Th17 plays a vital role in children with MPP through excessive inflammation. miR-29c and B7-H3 may be the new target for the prevention and treatment of MPP, and may be the novel and potential biomarkers for the assessment of prognosis.

Interactions between microRNA-200 family and Sestrin proteins in endometrial cancer cell lines and their significance to anoikis

In the present study, we intend to determine whether Sestrin proteins 1, 2, and 3 (SESN1-3) are targets of microRNA-200 family (miR-200) in endometrial cancer (EC) Ishikawa, AN3CA, KLE, and RL 95-2 cell lines and to investigate how these potential interactions influence anoikis resistance of EC cell lines. The luciferase reporter assay, qRT-PCR, and western blotting assays were used to verify whether SESN1-3 are direct targets of miR-200. Moreover, the anoikis assay and transient transfections of miR-200 mimics or inhibitors into EC cell lines were performed to evaluate the modulatory role of miR-200 and SESN proteins on anoikis resistance. We demonstrated that SESN2 protein is a direct target of mir-141 in KLE and RL-95-2 EC cell lines and the functional interaction of miR-141 and SESN2 protein has a downstream effect on anoikis resistance and SESN2 expression level in Ishikawa and AN3CA cell lines. Moreover, we have shown that SESN3 protein is a direct target of miR-200b, miR-200c, and miR-429 in Ishikawa, AN3CA, and KLE cell lines. Our results show that manipulation of miR-200b, miR-200c, and miR-429 expression patterns also has an influence on anoikis resistance in EC cell lines. In conclusion, we identified new interactions between miR-200 and the oxidative stress response SESN proteins that affect anoikis resistance in human EC cells.

LINC00511 knockdown enhances paclitaxel cytotoxicity in breast cancer via regulating miR-29c/CDK6 axis

AimsDrug resistance is becoming a major clinical challenge to the success of breast cancer treatment. Compelling evidence has shown the association between the deregulated long non-coding RNAs (lncRNAs) and drug resistance in various malignancies. However, the effects of long intergenic noncoding RNA 00511 (LINC00511), a newly identified oncogenic lncRNA, on the drug resistance of breast cancer cells remain unknown. Main methodsRT-qPCR was performed to detect the expressions of LINC00511, miR-29c, and cyclin dependent kinase 6 (CDK6) in breast cancer tissues and cells. Pearson correlation analysis was used to analyze the correlation between miR-29c, CDK6 and LINC00511 expression in breast cancer tissues. The interactions between LINC00511, CDK6 and miR-29c were explored by luciferase reporter assay, RT-qPCR and western blot. MTT assay and flow cytometry analysis were applied to evaluate paclitaxel cytotoxicity. Key findingsLINC00511 and CDK6 were upregulated while miR-29c was downregulated in breast cancer tissues and cells. miR-29c was negatively correlated with LINC00511 and CDK6 expression while LINC00511 was positively correlated with CDK6 expression in breast cancer tissues. LINC0051 directly interacted with miR-29c to suppress its expression. LINC00511 knockdown enhanced paclitaxel cytotoxicity in breast cancer cells by upregulating miR-29c. CDK6 was identified as a target of miR-29c. CDK6 knockdown attenuated the effects of miR-29c inhibition on paclitaxel cytotoxicity in breast cancer cells. LINC00511 positively regulated CDK6 expression in breast cancer cells. SignificanceLINC00511 knockdown enhanced paclitaxel cytotoxicity in breast cancer cells via regulating miR-29c/CDK6 axis.

Metastasis-associated protein 1, modulated by miR-30c, promotes endometrial cancer progression through AKT/mTOR/4E-BP1 pathway

ObjectiveThough metastasis-associated protein 1 (MTA1) is widely overexpressed in human cancers and is associated with advanced clinicopathological characteristics and survival in related diseases, the association between MTA1 and endometrial cancer (EC) is little known and needs to be studied. MethodsWestern blot and immunohistochemistry were used to analyze protein expression level of cells and tissues, while real-time PCR was used for RNA detection. Bioinformatics tool analysis revealed the relationship between MTA1 and clinicopathological characteristics and survival. CCK-8 assay, colony-formation assay, cell scratch assay, and Transwell assay were performed to determine cell proliferation, migration and invasion abilities, respectively. ResultsThe expression level of MTA1 was significantly higher in human EC tissues than in normal endometrium. MTA1 expression was correlated positively with lymph nodes metastasis and poor survival rate in EC. Experimentally overexpressed MTA1 could promote cell proliferation, migration and invasion abilities of EC cell lines Ishikawa, HEC-1B, and RL-952, while reduction of MTA1 inhibited these cell biological behaviors. Moreover, MTA1 could also reverse the negative effect of miR-30c, a direct modulator of MTA1, on EC cells. Our research also revealed that overexpression of MTA1 contributed to EC tumor growth, while knockdown of MTA1 resulted in tumor growth inhibition. Additionally, the phosphorylation levels of mTOR (S2448) and 4E-BP1 (T37/46) changed significantly along with AKT (T308) under regulation of MTA1, both in vivo and vitro. ConclusionOur results showed that MTA1, as a downstream target of miR-30c, might promote EC progression via AKT/mTOR/4E-BP1 pathway, which indicated the potential therapy target of MTA1 in EC.

MiR-30c exerts tumor suppressive functions in colorectal carcinoma by directly targeting BCL9.

Colorectal carcinoma (CRC) remains a leading health threat worldwide due to its high mortality. MicroRNA (miR-30c) is an important tumor suppressor in various cancers. B cell lymphoma 9 (BCL9) is one of the candidate genes for cancers. The synergistic effects of miR-30c and BCL9 in CRC progression remain to be carefully elucidated. Fifty pairs of CRC samples and matched adjacent non-tumor tissues were collected from Yantai Yuhuangding Hospital between 2015 and 2017. MiR-30c and BCL9 expression levels were measured by quantitative Real-time polymerase chain reaction (qRT-PCR) in CRC tissues and cell lines. The 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to determine the influence of miR-30c on the proliferation ability of CRC cells. Target Scan was used to predict the potential target of miR-30c. Then, luciferase assay was performed to confirm the prediction. In addition, we also investigated the biological influence of BCL9 on miR-30c-mediated functions in CRC. We found that miR-30c was significantly decreased in CRC tissues and cell lines while the BCL9 expression level was prominently increased in CRC tissues and cells. Additionally, the miR-30c expression was negatively correlated with BCL9 expressions in CRC tissues. Furthermore, the findings of this study also showed that BCL9 was a direct target of miR-30c in CRC and miR-30c could inhibit the CRC proliferation by binding to its 3'-UTR. This study showed that miR-30c overexpression inhibited CRC proliferation via the regulation of BCL9, suggesting that miR-30c may be a new molecular therapeutic target for CRC.

Autocrine TGF-β1/miR-200s/miR-221/DNMT3B regulatory loop maintains CAF status to fuel breast cancer cell proliferation.

Cancer-associated fibroblasts (CAFs) remain active even in the absence of cancer cells. However, the molecular mechanism underlying the sustained active status of CAFs is largely unrevealed. We found that in CAFs, DNMT3B was not only a target of miR-200b, miR-200c and miR-221, but was able to induce DNA methylation of miR-200s promoters. DNMT3B eventually reached a stably high level by the counteracting effect of decreasing miR-200b/c and increasing miR-221 in normal fibroblasts (NFs) with long-term exogenous TGF-β1 treatment, and DNMT3B further led to a low level of miR-200s which established CAF activation. Meanwhile, miR-200s/miR-221/DNMT3B signaling sustained autocrine TGF-β1 maintaining active CAF status. Destruction of the autocrine TGF-β1/miR-200s/miR-221/DNMT3B signaling led to demethylation of miR-200s promoters and further restored the NF phenotypes. Moreover, we confirmed that TCF12, the target of miR-141, stimulated c-Myc/Cyclin D1 axis in breast cancer cells to promote cancer growth by enhancing CXCL12 of CAFs. The current study reveals that the TGF-β1/miR-200s/miR-221/DNMT3B regulatory loop is responsible for the maintenance of CAFs status and is also necessary for CAF function in promoting malignance of breast cancer, which provides a potential target for CAF-driven therapeutic strategy.

MicroRNA-200c promotes tumor cell proliferation and migration by directly targeting dachshund family transcription factor 1 by the Wnt/β-catenin signaling pathway in nasopharyngeal carcinoma.

The purpose of the present study was to determine the crucial role of microRNAs (miRNAs/miRs) involved in the proliferation and migration of nasopharyngeal carcinoma (NPC) and to investigate their underlying mechanisms. In this study, we focused on the expression and function of miR-200c in NPC. First, we found the expression level of miR-200c in NPC cells and tissues was upregulated, and it was suggested that the high expression of miR-200c accelerated the proliferation and migration of NPC cells in vitro. Notably, a result of the present study was that the cell fate determination factor dachshund family transcription factor 1 (DACH1) was identified as a direct target of miR-200c. Suppression of miR-200c expression in NPC cells increased endogenous DACH1 mRNA and protein levels, which was negatively correlated with miR-200c. Meanwhile, DACH1 was shown to regulate the Wnt/β-catenin signaling pathway. Accordingly, it was concluded that miR-200c exerted a tumor-promoting role in NPC development by targeting DACH1, which may contribute to the increase in the rates of NPC proliferation and migration. miR-200c may be a potential diagnostic and prognostic biomarker for NPC.

MiR-29c regulates resistance to paclitaxel in nasopharyngeal cancer by targeting ITGB1

Paclitaxel (Taxol) is an anticancer taxane drug commonly used in the treatment of nasopharyngeal carcinoma (NPC). However, resistance to paclitaxel is a major difficulty in developing an effective therapy against NPC. MicroRNAs (miRNAs) are known to regulate genes that are involved in drug resistance. We assessed the effects of miR-29c, an miRNA identified in a genome-wide study of Taxol resistance, on genes associated with resistance in NPC cells. We established Taxol resistance in two human NPC cell lines, SUNE-1 and C666-1 (SUNE-1-Taxol and C666-1-Taxol) and found that miR-29c was downregulated and integrin beta-1 (ITGB1) was upregulated in Taxol-resistant NPC cells compared with parental NPC cells. Further investigations using a TUNEL assay and BAX/BCL-2 ratio, found that overexpression of miR-29c and knockdown of ITGB1 can resensitize drug-resistant NPC cells to Taxol and promote apoptosis. In addition, a dual-luciferase reporter assay indicated that ITGB1 is the target of miR-29c. Furthermore, silencing miR-29c markedly increased Taxol-resistant NPC tumor growth in a nude mouse xenograft model while knockdown of ITGB1 reversed this result. Overall, these data demonstrate that miR-29c regulates resistance to Taxol in NPC by targeting ITGB1. Our research indicates that miR-29c may have potential use in Taxol-resistant NPC therapy.

MiR-30c Impedes Glioblastoma Cell Proliferation and Migration by Targeting SOX9.

miR-30c has been acknowledged as a tumor suppressor in various human cancers, such as ovarian cancer, gastric cancer, and prostate cancer. However, the role of miR-30c in glioblastoma (GBM) needs to be investigated. In our study, we found that the expression of miR-30c was significantly downregulated in GBM tissues and cell lines. We found that overexpression of miR-30c inhibited cellular proliferation of GBM cells in vitro and in vivo. More GBM cells were arrested in the G0 phase after miR-30c overexpression. Moreover, we showed that miR-30c overexpression suppressed the migration and invasion of GBM cells. Mechanistically, we found that SOX9 was a direct target of miR-30c in GBM cells. Overexpression of miR-30c inhibited the mRNA and protein levels of SOX9 in GBM cells. Moreover, there was a negative correlation between the expression of miR-30c and SOX9 in GBM tissues. Finally, we showed that restoration of SOX9 in GBM cells reversed the proliferation, migration, and invasion of GBM cells transfected with miR-30c mimic. Collectively, our results demonstrated that miR-30c suppressed the proliferation, migration, and invasion of GBM cells via targeting SOX9.

Regulation of Cell Cycle Regulatory Proteins by MicroRNAs in Uterine Leiomyoma.

The objective of this study was to determine whether miR-93, miR-29c, and miR-200c, which we previously reported to be downregulated in leiomyomas, target cell cycle regulatory proteins that influence cell proliferation. Based on TargetScan algorithm 3 cell cycle regulatory proteins namely, E2F transcription factor 1 (E2F1), Cyclin D1 (CCND1) and CDK2 which were predicted to be targets of these miRNAs were further analyzed. In 30 hysterectomy specimens, we found the expression of E2F1 and CCND1 messenger RNA (mRNA) was increased in leiomyoma as compared to matched myometrium, with no significant changes in CDK2 mRNA levels. There was a significant increase in the abundance of all 3 proteins in leiomyoma in comparison with matched myometrium. Using luciferase reporter assay, we demonstrated E2F1 and CCND1 are targets of miR-93 and CDK2 is a target of miR-29c and miR-200c. We confirmed these findings through transfection studies in which transfection of primary leiomyoma cells with miR-93 resulted in a significant decrease in the expression of E2F1 and CCND1 mRNA and protein levels, whereas knockdown of miR-93 had the opposite effect. Similarly, overexpression of miR-29c and miR-200c in leiomyoma cells inhibited the expression of CDK2 protein and mRNA, whereas knockdown of this microRNAs (miRNA) had the opposite effect. Transfection of miR-29c, miR-200c, and miR-93 in primary leiomyoma cells resulted in a time-dependent inhibition of cell proliferation and cell motility. These results collectively indicate that the 3 miRNAs known to be downregulated in fibroid tumors are critical in regulation of cell proliferation because of their effects on 3 key cell cycle regulatory proteins, which are overexpressed in uterine leiomyomas.

Identification of miR-29c and its Target FBXO31 as a Key Regulatory Mechanism in Esophageal Cancer Chemoresistance: Functional Validation and Clinical Significance.

Rationale: Dysregulated microRNA (miRNA) expressions in cancer can contribute to chemoresistance. This study aims to identify miRNAs that are associated with fluorouracil (5-FU) chemoresistance in esophageal squamous cell carcinoma (ESCC). The potential of miR-29c as a novel diagnostic, prognostic and treatment-predictive marker in ESCC, and its mechanisms and therapeutic implication in overcoming 5-FU chemoresistance were explored.Methods: The miRNA profiles of an ESCC cell model with acquired chemoresistance to 5-FU were analyzed using a Taqman miRNA microarray to identify novel miRNAs associated with 5-FU chemoresistance. Quantitative real-time PCR was used to determine miR-29c expression in tissue and serum samples of patients. Bioinformatics, gain- and loss-of-function experiments, and luciferase reporter assay were performed to validate F-box only protein 31 (FBXO31) as a direct target of miR-29c, and to identify potential transcription factor binding events that control miR-29c expression. The potential of systemic miR-29c oligonucleotide-based therapy in overcoming 5-FU chemoresistance was evaluated in tumor xenograft model.Results: MiR-29c, under the regulatory control of STAT5A, was frequently downregulated in tumor and serum samples of patients with ESCC, and the expression level was correlated with overall survival. Functional studies showed that miR-29c could override 5-FU chemoresistance in vitro and in vivo by directly interacting with the 3'UTR of FBXO31, leading to repression of FBXO31 expression and downstream activation of p38 MAPK. Systemically administered miR-29c dramatically improved response of 5-FU chemoresistant ESCC xenografts in vivo.Conclusions: MiR-29c modulates chemoresistance by interacting with FBXO31, and is a promising non-invasive biomarker and therapeutic target in ESCC.