LncRNA SNHG15 promotes hepatocellular carcinoma progression by sponging miR-141-3p

Small nucleolar RNA host gene 15 (SNHG15) is a long noncoding RNA (lncRNA), which promotes progression of multiple cancers. Its specific function in hepatocellular carcinoma (HCC), however, is uncertain. The aims of our study were, therefore, to explore the role of SNHG15 in HCC. SNHG15 and miR-141-3p expression were assessed via quantitative real-time PCR (qRT-PCR) in 58 paired HCC samples and adjacent matched adjacent normal tissues. CCK-8 assay, flow cytometric examination, and wound healing/invasion assays were used to respectively assess how SNHG15 influences cell proliferation, the cell cycle, and the migratory and invasive potential of HCC cells. MicroRNA (miRNAs) that targeted SNHG15 was screened by Starbase2.0 and identified by RNA immunoprecipitation and luciferase reporter assays. SNHG15 expression was markedly increased, whereas miR-141-3p expression was substantially reduced in HCC cells and tissue samples relative to normal controls. When SNHG15 was knocked down, this resulted in a significant disruption to the proliferation, as well as the invasive and migratory ability of these HCC cells. miR-141-3p was also found to be an SNHG15 target in HCC cells. Furthermore, miR-141-3p inhibitor partially reversed the observed SNHG15 depletion-mediated reduction in HCC proliferation, migration, and invasion. By repressing miR-141-3p, SNHG15 could modulate zinc finger E-box binding homeobox 2 (ZEB2) and E2F transcription factor 3 (E2F3) expression, both of which are miR-141-3p targets. These finding suggested that SNHG15 promoted HCC progression via negative regulation of miR-141-3p, thus identifying a potential novel HCC treatment pathway.

LncRNA XIST enhanced TGF-β2 expression by targeting miR-141-3p to promote pancreatic cancer cells invasion

The level of expression of long non-coding RNA (LncRNA) X-inactive specific transcript (XIST) is up-regulated in pancreatic cancer (PC). However, the role of XIST in PC and the underlying mechanism are still unknown. The present study aimed to elucidate how XIST participates in PC and its potential target, miR-141-3p. We detected the XIST expression in PC tissues and cells by qRT-PCR. Cell proliferation was measured using a CCK8 kit, and the migration and invasion of cells was measured by Transwell assay. Silencing XIST and miR-141-3p was performed with transfection by Lipofectamine kit. Binding assay was conducted by luciferase reporter assay. Protein expression was examined by Western blot. These results indicate that (i) XIST is highly expressed in tumor tissues while miR-141-3p is down-regulated. (ii) Silencing XIST inhibits the pancreatic cell proliferation, migration and invasion. (iii) MiR-141-3p inhibitor alleviates the inhibitory effect by siXIST in PC cell lines. (iv) MiR-141-3p directly interacts with XIST and also negatively regulates transforming growth factor-β 2 (TGF-β2) expression. (v) Overexpression of XIST attenuates the inhibition of TGF-β2 expression by miR-141-3p. The conclusion, is that XIST could promote proliferation, migration and invasion of PC cells via miR-141-5p/TGF-β2 axis.

The microRNA-141-3p/ CDK8 pathway regulates the chemosensitivity of breast cancer cells to trastuzumab

AIMS

This study was conducted to explore the function of microRNA-141-3p/cyclin-dependent kinase 8 (miR-141-3p/CDK8) in regulating trastuzumab resistance of breast cancer cells.

MATERIALS AND METHODS

Microarray analysis was performed to screen microRNAs that are differentially expressed in wild type and trastuzumab-resistant (TR) breast cancer cell lines. TargetScan helped predict the target gene of miR-141-3p. The regulatory relationship was confirmed through a luciferase reporter assay, quantitative reverse transcriptase polymerase chain reaction, and Western blot analysis. The MTT assay, transwell invasion assay, and wound scratch assay were performed to measure the proliferative, invasive, and migratory ability of breast cancer cells, respectively. Tumor cell xenografts in nude mice were conducted to observe the effect of miR-141-3p on trastuzumab resistance in breast cancer cells in vivo. The enzyme-linked immunosorbent assay was used to detect protein secretion.

RESULTS

miR-141-3p was downregulated in the drug-resistant cell lines. CDK8 was proved to be a target gene of miR-141-3p. Transfection of miR-141-3p or CDK8 small interfering RNA (siRNA) reversed the resistance to trastuzumab in TR cell lines and suppressed cell invasion and migration. Dysregulation of transforming growth factor beta (TGF-β) was detected when the expression of CDK8 was silenced by CDK8 siRNA, and downregulation of TGF-β had a notable effect on reducing the phosphorylation of SMAD2/SMAD3.

CONCLUSION

miR-141-3p could restore the sensitivity to trastuzumab in breast cancer cells by repressing CDK8, which might regulate the phosphorylation levels of SMAD2/SMAD3 via TGF-β.

Role of microRNA-141-3p in the progression and metastasis of hepatocellular carcinoma cell

Hepatocellular carcinoma (HCC) is a leading cause of cancer related death worldwide. However, the mechanisms underlying HCC progression and metastasis are still in obscure. Here, we used bioinformatic analysis to identify miRNAs that regulate GP73, a specific marker for HCC diagnosis and prognosis. The correlations between miR-141-3p and clinic-pathological factors were analyzed in HCC patient samples; proliferation, migration, invasion, and colony formation were studied using established HCC cell lines. Expression levels of target genes (miR-141-3p, GP73, E-cadherin, N-cadherin, occludin, vimentin, and cytokeratin 18) were detected by either Western blot or qRT-PCR analysis. Xenograft models were established to evaluate tumor growth and metastasis. MiR-141-3p was significantly reduced in HCC tumors and cell lines, highly correlated with tumor progression. In contrast, GP73 was negatively correlated with miR-141-3p in HCC tumors. MiR-141-3p overexpression significantly decreased HCC cell proliferation, migration, and invasion by inhibiting epithelial-mesenchymal transition (EMT). GP73 overexpression partially restored the inhibitory effects of miR-141-3p, while miR-141-3p overexpression markedly inhibited tumor growth and pulmonary metastasis, which were partially reversed by GP73 overexpression. Our findings suggest that miR-141-3p targets GP73 to reverse EMT, subsequently inhibiting HCC progression and metastasis. Thus, overexpression of miR-141-3p could serve as a therapeutic strategy to arrest HCC.

miR-21-5p, miR-141-3p, and miR-205-5p levels in urine-promising biomarkers for the identification of prostate and bladder cancer

BACKGROUND

Early detection of cancers improves patients' survival and decreases the treatment cost. Unfortunately, the current methods for diagnosis of bladder and prostate cancers, two most common urothelial malignancies, suffer from a low sensitivity and specificity. MicroRNAs, as a group of endogenously produced non-coding RNAs, regulate gene expression and their expression is observed to be altered in many cancers and cancer progression phenomena. The remarkable stability of microRNAs in biofluids and their unique expression pattern in different pathological conditions make them an appealing, noninvasive diagnostic method in cancer diagnosis. Our objective is to identify microRNAs as biomarkers in urine samples of bladder and prostate cancers to improve the existing diagnostic methods in this field.

MATERIALS AND METHODS

In this study, urine samples from 110 men with either bladder (n = 45) or prostate (n = 23) cancer, benign prostatic hyperplasia (n = 22) and healthy controls (n = 20) were collected. qPCR was used to evaluate the expression level of miR-21-5p, miR-141-3p, and miR-205-5p in these samples. The sensitivity and specificity of these microRNAs were determined using ROC curve analysis.

RESULTS

The analysis of the data revealed that miR-21-5p, miR-141-3p, and miR-205-5p are differentially expressed in urine of bladder and prostate cancer patients. All these three microRNAs were upregulated in these samples and they were also able to differentiate benign prostatic hyperplasia from malignant cases. The statistical analyses revealed a good specificity for each individual microRNA.

CONCLUSION

The results show that these three urine-based microRNAs might be a good choice to implement a specific and non-invasive diagnostic tool for bladder and prostate cancer. The expression pattern of all three microRNAs was particularly useful to distinguish benign and invasive tumors in prostate cases. From the patients' perspective the improvement of the diagnostic situation is awaited eagerly.

Exosomal transfer of obesity adipose tissue for decreased miR-141-3p mediate insulin resistance of hepatocytes

Exosomes, the nano-vesicles released from living cells, were the important mediator for cell-to-cell communication. In order to clarify whether the exosomes derived from obesity adipose tissue mediate insulin resistance of hepatocytes, we extract the exosomes from the adipose tissue of different mice models. Exosomes derived from ob/ob mice (Ob-exosomes), B6 mice fed with a high-fat diet (HFD-exosomes) and normal B6 mice (WT-exosomes) displayed similar size and molecular makers, but their effect on the insulin sensitivity of hepatocytes were obviously different or opposite. Abundant exosomal miRNAs in Ob-, HFD- and WT-exosomes were detected by the Next Generation Sequencing. The levels of miR-141-3p in Ob- and HFD-exosomes were significantly lower than WT-exosomes. MiR-141-3p can be effectively delivered into AML12 cells accompanied by the absorption of exosomes, but the absorption of miR-141-3p into AML12 cells could be blocked by GW4869, an inhibitor of exosome biogenesis and release. Importantly, the Ob-exosomes or miR-141-3p knockdown in WT--exosomes obviously inhibited the insulin response and glucose uptake of AML12 cells, however, the inhibitory effects on insulin function disappeared after the overexpression of miR-141-3p in Ob-exosomes or AML12 cells. The effects of miR-141-3p on insulin function could be achieved by improving the level of phosphorylation of AKT and enhancing insulin signal transduction. Therefore, the absorption of hepatocytes for exosomes released from obesity adipose tissue containing less miR-141-3p than healthy adipose tissue can significantly inhibit the insulin sensitivity and glucose uptake. Our study may certify a novel mechanism that the secretion of "harmful" exosomes from obesity adipose tissues cause insulin resistance.

Elevated microRNA-141-3p in placenta of non-diabetic macrosomia regulate trophoblast proliferation

BACKGROUND

Several studies have reported microRNAs (miRNAs) could regulate the placental development, though the role and mechanism of miRNAs in the development of non-diabetic macrosomia (NDFMS) remains unclear.

METHODS

To identify the aberrantly expressed key miRNAs in placenta of NDFMS, we employed a strategy consisting of initial screening with miRNA microarray and further validation with quantitative RT-PCR assay (qRT-PCR). In vitro cellular model and a mouse pregnancy model were used to delineate the functional effects of key miRNA on proliferation, invasion, and migration.

FINDINGS

miR-141-3p was identified as the key miRNA with expression level significantly higher in placentas of NDFMS compared with those from normal controls. Overexpressed miR-141-3p in HTR-8/SVneo cells contributed to increased cell proliferation, invasion, and migration. miR-141-3p inhibition in HTR-8/SVneo cells resulted in decreased cell proliferation and invasion. Significantly increased infant birth weight was observed in late pregnancy of C57BL/6J mice treated with miR-141-3p agomir. However, no significant difference was found in early pregnancy of C57BL/6J mice treated with miR-141-3p agomir.

INTERPRETATION

miR-141-3p could stimulate placental cell proliferation to participate in the occurrence and development of NDFMS.

MiR-141-3p suppresses gastric cancer induced transition of normal fibroblast and BMSC to cancer-associated fibroblasts via targeting STAT4

BACKGROUND

Cancer associated fibroblasts (CAFs) are known to be crucial constituents of cancer microenvironment (CME) and play an important role in initiation, progression and metastasis of various types of cancer, such as oral cancer, pancreatic cancer, and gastric cancer. CAFs are usually derived from normal fibroblasts (NFs), but the mechanism of the transition in gastric cancer has not yet been fully elucidated.

METHODS

qRT-PCR and western blot were employed to investigate differences of miR-141 and STAT4 expression respectively. The CAF-like features and wnt/β-catenin pathway related proteins in NF or BMSC were assessed by qRT-PCR or western blot after treated with the conditioned medium from different indicated groups of gastric cancer cells. The invasion and migration ability of AGS cells after transfection were analyzed by Transwell assay and wound healing assay. Dual-luciferase report assay was employed to determine the direct binding of miR-141 to STAT4 3' UTR.

RESULTS

For the first time, the present study found that STAT4 over-expression in gastric cancer cells induced NFs to obtain CAF-like features via activating wnt/β-catenin pathway. Further gain-of-function and loss-of-function analysis revealed that miR-141 not only limited the migration and invasion of the gastric cancer cells, but also inhibited the transition of NFs and BMSC to CAFs. The luciferase assay indicated that miR-141 directly targeted the 3'-UTR predictive sequence of STAT4.

CONCLUSION

Our data showed that miR-141 inhibited migration and invasion of gastric cancer cells and inhibited transition from NFs to CAFs via targeting STAT4/wnt/β-catenin pathway.

Co-expression profiling of plasma miRNAs and long noncoding RNAs in gastric cancer patients

PURPOSE

The recent researches indicate that differential non-coding RNAs expression signatures could be associated with the pathogenesis of gastric cancer (GC). However, there are few studies focused on lncRNA-miRNAs co-expression profiling in GC patients. Therefore, in the present study the expression of H19 and MEG3 and their related miRNAs including miR-148a-3p, miR-181a-5p, miR-675-5p and miR-141-3p were determined in the plasma samples of GC patients and controls.

MATERIALS AND METHODS

This case-control study included 62 GC patients and 40 age- sex matched controls. The non-coding RNA levels were assessed by real-time PCR. Further, using in silico analysis, we identified shared targets of studied miRNAs and performed GC-associated pathway enrichment analysis.

RESULTS

Our results showed that the H19 level was significantly (P = 0.008) elevated and MEG3 expression was significantly (P = 0.002) down-regulated in GC patients compared to healthy participants. Furthermore, it was revealed that the miR-675-5p level was increased, while miR-141-3p plasma levels were significantly reduced in GC patients (P < 0.05). We did not observe a significant difference for miR-148a-3p (P = 0.682) and miR-181a-5p (P = 0.098) expression between groups. In addition, the expression levels of H19, MEG3 and miR-148a-3p were associated with some clinicopathological features of patients (P < 0.05). ROC analysis revealed that a combination of H19, MEG3 and miR-675-5p levels able to discriminate controls and GC subjects with 88.87% sensitivity and 85% specificity (AUC, 0.927; 0.85-0.96 CI, P < 0.0001).

CONCLUSION

The results of current study demonstrated that combination of H19, MEG3 and miR-675-5p expression levels could provide a potential diagnostic panel for GC.

MiR-141-3p Suppresses Tumor Growth and Metastasis in Papillary Thyroid Cancer via Targeting Yin Yang 1

MicroR-141-3p has been found to be downregulated in papillary thyroid carcinoma (PTC), while little is known about the cellular functions and precise signals elicited by miR-141-3p in PTC. The results of this study indicated that the expression of miR-141-3p was aberrantly down-regulated in PTC tissues and cell lines, compared with the adjacent normal tissues and normal thyroid epithelial cells. Furthermore, the miR-141-3p expression level was negatively associated with TNM stage and lymph node metastasis in PTC. Expression of miR-141-3p effectively inhibited cell growth, promoted apoptosis, and suppressed invasion in PTC cells. Meanwhile, miR-141-3p knockdown with miR-141-3p inhibitor reversed these effects. Consistent with the in vitro study, miR-141-3p also exhibited anti-neoplastic activity in vivo. Moreover, the results revealed that miR-141-3p directly recognized the 3' untranslated region (3'UTR) of Yin Yang 1 (YY1) and negatively regulated the expression of YY1 at both protein and mRNA levels. Ectopic expression of YY1 could effectively abrogate the anti-metastatic and proapoptotic effects of miR-141-3p. In summary, the findings suggested that miR-141-3p can act as a tumor suppressor in PTC and may be a potential therapeutic target for PTC treatment. Anat Rec, 302:258-268, 2019. © 2018 Wiley Periodicals, Inc.

Decreased c-Myc mRNA Stability via the MicroRNA 141-3p/AUF1 Axis Is Crucial for p63α Inhibition of Cyclin D1 Gene Transcription and Bladder Cancer Cell Tumorigenicity

Bladder cancer (BC) ranks as the sixth most common cancer in the United States and is the leading cause of death in patients with urinary malignancies. p63 is a member of the p53 family and is believed to function as a tumor suppressor in human BCs. Our most recent studies revealed a previously unknown function of the RING of XIAP in promoting microRNA 4295 (miR-4295) transcription, thereby reducing p63α protein translation and enhancing normal urothelial transformation, whereas p63α upregulates hsp70 transcription, subsequently activating the HSP70/Wasf3/Wave3/matrix metalloproteinase 9 (MMP-9) axis and promoting BC cell invasion via initiating the transcription factor E2F1. In this study, we found that p63α inhibited cyclin D1 protein expression, subsequently decreasing the ability of BC cell anchorage-independent growth in vitro and tumorigenicity in vivo Mechanistic studies demonstrated that p63α expression is able to downregulate cyclin D1 gene transcription through attenuation of c-Myc mRNA stability. We further show that the reduction of miR-141-3p expression by p63α directly releases its inhibition of 3' untranslated region (UTR) activity of AU-rich element RNA-binding factor 1 (AUF1) mRNA, thereby increasing AUF1 protein translation and further resulting in degradation of c-Myc mRNA, which, in turn, reduces cyclin D1 gene transcription and BC cell anchorage-independent growth. Collectively, our results demonstrate that p63α is a negative regulator of BC cell tumorigenic growth, a distinctly different function than its promotion of BC invasion, thus providing further new insight into the "two faces" of p63α in regulation of BC cell tumorigenic growth and progression/invasion.

Down-regulation of lncRNA-ATB inhibits epithelial-mesenchymal transition of breast cancer cells by increasing miR-141-3p expression

Long noncoding RNA activated by transforming growth factor-beta (lnc-ATB) is abnormally expressed in a number of tumor types. The aim of this study was to investigate the expression of lnc-ATB and miR-141-3p, and to determine whether lnc-ATB can regulate epithelial-mesenchymal transition (EMT) by miR-141-3p in breast cancer. Here, we found that lnc-ATB was highly expressed, whereas there was low expression of miR-141-3p in breast cancer tissues and cells. Knockdown of lnc-ATB in two breast cancer cell lines (MDA-MB-231 and BT549) significantly increased miR-141-3p expression. Down-regulation of lnc-ATB resulted in a morphological change of breast cancer cells from spindle-like to a round shape, and in a remarkable inhibition of cell migration and invasion, which were reversed by miR-141-3p inhibitor. Furthermore, we demonstrated that lnc-ATB knockdown decreased ZEB1, ZEB2, N-cadherin, and vimentin expression, and promoted E-cadherin expression, while miR-141-3p inhibitor could reverse those effects. Moreover, we proved that miR-141-3p directly bound to the 3' untranslated region (UTR) of ZEB1 and ZEB2 and negatively regulated ZEB1 and ZEB2 expression. Taken together, our results show that knockdown of lnc-ATB significantly inhibits the EMT process of breast cancer cells by increasing the expression of miR-141-3p, indicating that lnc-ATB might serve as a novel therapeutic target for breast cancer.

microRNA-141-3p fosters the growth, invasion, and tumorigenesis of cervical cancer cells by targeting FOXA2

microRNA (miR)-141-3p has context-dependent effects on tumor progression. In this study, we attempted to explore the expression and function of miR-141-3p in cervical cancer. We found that miR-141-3p expression was significantly increased in cervical cancer specimens relative to normal cervical tissues. Moreover, miR-141-3p levels were associated with tumor size and lymph node metastasis status. Ectopic expression of miR-141-3p significantly increased cervical cancer cell proliferation, colony formation, invasion, and epithelial to mesenchymal transition, whereas depletion of miR-141-3p suppressed cervical cancer cell proliferation and invasion. FOXA2 was identified to be a target of miR-141-3p. Overexpression of miR-141-3p led to a marked inhibition of endogenous FOXA2 in cervical cancer cells. FOXA2 silencing phenocopied the effects of miR-141-3p overexpression on cervical cancer cell proliferation and invasion. Enforced expression of FOXA2 blocked the effects of miR-141-3p on cervical cancer cell proliferation and invasion. miR-141-3p overexpression significantly accelerated the growth of xenograft tumors, which was accompanied by a striking reduction in FOXA2 expression. miR-141-3p acts as an oncogene in cervical cancer largely through repression of FOXA2. Targeting miR-141-3p may represent a potential therapeutic strategy for cervical cancer.

Age-Related Changes in MicroRNA in the Rat Pituitary and Potential Role in GH Regulation

The growth hormone/insulin-like growth factor 1 (GH/IGF-1) axis has recently been recognized as an important factor related to the longevity of many organisms. MicroRNAs (miRNAs or miRs) could also participate in diverse biological processes. However, the role of miRNAs in the decline of pituitary GH during the growth process remains unclear. To better characterize the effects of miRNAs on the pituitary, we used a miRNA microarray to investigate the miRNA profile in the rat pituitary from postnatal development throughout the growth process. Then, in vitro experiments were conducted to analyze the miRNAs' potential roles related to GH regulation. Taken together, the microarray results indicated that there were 22 miRNAs differentially expressed during pituitary development. The bioinformatics analysis suggested that the most differentially expressed miRNAs may participate in multiple pathways associated with the pituitary function. Furthermore, the in vitro findings demonstrated that miR-141-3p was involved in GH regulation.

LncRNA MIR22HG negatively regulates miR-141-3p to enhance DAPK1 expression and inhibits endometrial carcinoma cells proliferation

Emerging evidence has indicated that long non-coding RNAs (lncRNAs) play critical roles in tumor development and progression. Recent studies reported that lncRNA MIR22HG could play important roles in hepatocellular carcinoma and lung cancer progression. However, the expression and underlying mechanism of MIR22HG in endometrial cancer (EC) remain unclear. In the present study, qRT-PCR showed that MIR22HG expression was significantly downregulated in EC tissues. In vitro function assays showed that increased MIR22HG expression significantly inhibited EC cells proliferation, induced EC cells apoptosis, and arrested EC cells in G0/G1 phase. Furthermore, miR-141-3p was identified and confirmed to be the target of MIR22HG. Subsequently, DAPK1 was confirmed to be regulated by MIR22HG and miR-141-3p, and could play a positive role in inhibiting EC cells proliferation. Collectively, these data demonstrated that lncRNA MIR22HG could act as a tumor suppressor and inhibited EC cells proliferation through regulating miR-141-3p/DAPK1 axis, which provides a new therapeutic target for EC treatment.

Transplantation of endothelial progenitor cells attenuated paraquat-induced acute lung injury via miR-141-3p-Notch-Nrf2 axis

Background

Paraquat (PQ) presents with high toxicity for humans and animals, and the lungs become the main target organ by the poisoning of PQ leading to acute lung injury. Endothelial progenitor cells (EPCs) were proved to have the repair function on acute lung injury (ALI). We aimed to invatigate the underlying mechanism of EPCs in PQ-induced ALI involving miR-141-3p.

Methods

Endothelial progenitor cells were isolated from peripheral blood of C57BL/6J mice and identified by flow cytometry. Lung wet-to-dry (W/D) weight ratios, lung injury score and the number of total leukocyte and the number of neutrophils in BALF were used to analyze the degree of lung injury. The transfection was performed with Lipofectamine 2000. The levels of miRNA and mRNA were determined by qRT-PCR, and the protein levels were detected by Western blot assay.

Results

Endothelial progenitor cells alleviated lung wet-to-dry (W/D) weight ratios, lung injury score and the number of total leukocyte and the number of neutrophils in BALF in PQ-induced ALI mice. EPCs inhibited miR-141-3p expression, and enhanced the levels of Notch-Nrf2 axis in PQ-induced ALI mice. MiR-141-3p knockdown reversed the PQ induced-inhibition on Notch-1 and Hesr1 expression. MiR-141-3p over-expression could inhibit the expression of Notch-1 pathway significantly in the pulmonary epithelial cell line MLE-12. Both miR-141-3p over-expression and si-Notch-1 abolished the protection effect of EPCs on lung injury induced by PQ in vivo.

Conclusions

Endothelial progenitor cells could provide therapeutic effect on PQ-induced ALI via miR-141-3p-Notch-Nrf2 Axis.

Downregulation of miR-141-3p promotes bone metastasis via activating NF-κB signaling in prostate cancer

Background

Clinically, prostate cancer (PCa) exhibits a high avidity to metastasize to bone. miR-141-3p is an extensively studied miRNA in cancers and downregulation of miR-141-3p has been widely reported to be involved in the progression and metastasis of several human cancer types. However, the clinical significance and biological roles of miR-141-3p in bone metastasis of PCa are still unclear.

Methods

miR-141-3p expression was examined in 89 non-bone metastatic and 52 bone metastatic PCa tissues by real-time PCR. Statistical analysis was performed to investigate the clinical correlation between miR-141-3p expression levels and clinicopathological characteristics in PCa patients. The biological roles of miR-141-3p in bone metastasis of PCa were evaluated both in vitro and a mouse intracardial model in vivo. Bioinformatics analysis, Western blot, luciferase reporter and miRNA immunoprecipitation assays were performed to explore and examine the relationship between miR-141-3p and its potential targets. Clinical correlation of miR-141-3p with its targets was examined in clinical PCa tissues.

Results

miR-141-3p expression is reduced in bone metastatic PCa tissues compared with non-bone metastatic PCa tissues. Low expression of miR-141-3p positively correlates with serum PSA levels, Gleason grade and bone metastasis status in PCa patients. Furthermore, upregulating miR-141-3p suppresses the EMT, invasion and migration of PCa cells in vitro. Conversely, silencing miR-141-3p yields an opposite effect. Importantly, upregulating miR-141-3p dramatically reduces bone metastasis of PC-3 cells in vivo. Our results further show that miR-141-3p inhibits the activation of NF-κB signaling via directly targeting tumor necrosis factor receptor-associated factor 5(TRAF5) and 6 (TRAF6), which further suppresses invasion, migration and bone metastasis of PCa cells. The clinical negative correlation of miR-141-3p expression with TRAF5, TRAF6 and NF-κB signaling activity is demonstrated in PCa tissues.

Conclusion

Our findings unravel a novel mechanism underlying the bone metastasis of PCa, suggesting that miR-141-3p mimics might represent a potential therapeutic avenue for the treatment of PCa bone metastasis.

Electronic supplementary material

The online version of this article (10.1186/s13046-017-0645-7) contains supplementary material, which is available to authorized users.

Exosomal miR-141-3p regulates osteoblast activity to promote the osteoblastic metastasis of prostate cancer

Exosomes from cancer cells, which contain microRNA and reach metastasis loci prior to cancer cells, stimulate the formation of a metastatic microenvironment. Previous studies have shown that exosomal miR-141-3p is associated with metastatic prostate cancer (PCa). However, the role and regulatory mechanism of miR-141-3p in the microenvironment of bone metastases require further study. In this study, we performed a series of experiments in vivo and in vitro to determine whether exosomal miR-141-3p from MDA PCa 2b cells regulates osteoblast activity to promote osteoblastic metastasis. We demonstrate that extracts obtained from cell culture supernatants contained exosomes and that miR-141-3p levels were significantly higher in MDA PCa 2b cell exosomes. Via confocal imaging, numerous MDA PCa 2b exosomes were observed to enter osteoblasts, and miR-141-3p was transferred to osteoblasts through MDA PCa 2b exosomes in vitro. Exosomal miR-141-3p from MDA PCa 2b promoted osteoblast activity and increased osteoprotegerin OPG expression. miR-141-3p suppressed the protein levels of the target gene DLC1, indicating its functional significance in activating the p38MAPK pathway. In animal experiments, exosomal miR-141-3p had bone-target specificity and promoted osteoblast activity. Mice injected with miR-141-3p-mimics exosomes developed apparent osteoblastic bone metastasis. Exosomal miR-141-3p from MDA PCa 2b cells promoted osteoblast activity and regulated the microenvironment of bone metastases, which plays an important role in the formation of bone metastases and osteogenesis damage in PCa. Clarifying the specific mechanism of bone metastasis will help generate new possibilities for the treatment of PCa.

miR-141-3p functions as a tumor suppressor modulating activating transcription factor 5 in glioma

Glioma is the most common malignant primary brain tumor which arises from the central nervous system. Our studies reported that an anti-apoptotic factor, activating transcription factor 5 (ATF5), is highly expressed in malignant glioma specimens and cell lines. Downregulation by dominant-negetive ATF5 could repress glioma cell proliferation and accelerate apoptosis. Here, we further investigate the upstream factor which regulates ATF5 expression. Bioinformatic analysis showed that ATF5 was a potential target of miR-141-3p. Luciferase reporter assay verified that miR-141-3p specifically targeted the ATF5 3'-UTR in glioma cells. Functional studied suggested that miR-141-3p overexpression inhibited proliferation and promoted apoptosis of glioma cells (U87MG and U251). Xenograft experiments proved the inhibition of miR-141-3p on glioma growth in vivo. Moreover, exogenous ATF5 without 3'-UTR restored the cell proliferation inhibition triggered by miR-141-3p. Taken together, we put forward that miR-141-3p is a new upstream target towards ATF5. It can serve as a crucial tumor suppressor in regulating the ATF5-regulated growth of malignant glioma.

MicroRNA-141-3p targets DAPK1 and inhibits apoptosis in rat ovarian granulosa cells

The polycystic ovary syndrome (PCOS) is a complex and heterogeneous endocrine disorder. MicroRNAs negatively regulate the expression of target genes at posttranscriptional level by binding to the 3' untranslated region of target genes. Our previous study showed that miR-141-3p was dramatically decreased in the ovaries of rat PCOS models. In this study, we aimed to characterize the target of miR-141-3p in rat ovarian granulosa cells. 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay showed that cell viability was dramatically increased when miR-141-3p was overexpressed but was decreased when miR-141-3p was interfered. Flow cytometry showed that cell apoptotic rate was dramatically decreased when miR-141-3p was overexpressed but was increased when miR-141-3p was interfered. Bioinformatics analysis predicted that death-associated protein kinase 1 (DAPK1) might be the target gene of miR-141-3p because the 3' untranslated region of DAPK1 contains sequences complementary to microRNA-141-3p. Transfection with miR-141-3p mimics and inhibitor into granulosa cells showed that both DAPK1 mRNA and protein levels were negatively correlated with miR-141-3p level. Dual-luciferase reporter assay established that DAPK1 was the target of miR-141-3p. Taken together, our data indicate that miR-141-3p may inhibit ovarian granulosa cell apoptosis via targeting DAPK1 and is involved in the etiology of PCOS.

A qRT-PCR and Gene Functional Enrichment Study Focused on Downregulation of miR-141-3p in Hepatocellular Carcinoma and Its Clinicopathological Significance

BACKGROUND

The clinical significance of miR-141-3p in hepatocellular carcinoma has not been verified. Therefore, we conducted this study to examine miR-141-3p expression and its clinical significance in hepatocellular carcinoma and to investigate the functions of its potential targets.

METHODS

The Cancer Genome Atlas database and the Gene Expression Omnibus database were used to explore the aberrant expression of miR-141-3p in hepatocellular carcinoma. Furthermore, we assessed the miR-141-3p levels in 95 hepatocellular carcinoma tissues with 95 matched adjacent tissues using real-time quantitative polymerase chain reaction. Moreover, a target gene prediction analysis of miR-141-3p, a natural language processing analysis for hepatocellular carcinoma using PubMed, and a gene functional enrichment analysis were conducted to search the potential function of miR-141-3p in the pathogenesis of hepatocellular carcinoma.

RESULTS

Regarding The Cancer Genome Atlas data, miR-141-3p levels were markedly downregulated in hepatocellular carcinoma tissue compared to para- or nontumor tissue (4.6112 [1.7096] vs 5.3053 [1.4254], P = .045). MiR-141-3p expression was reduced in patients with hepatocellular carcinoma with a low pathologic T stage (P = .006), a low grade (P = .01), elderly hepatocellular carcinoma patients (P = .001), and male patients with hepatocellular carcinoma (P = .01) compared with that in patients with hepatocellular carcinoma with high pathologic T stages, high grades, young patients with hepatocellular carcinoma, and female patients with hepatocellular carcinoma. However, according to the Gene Expression Omnibus database, no significant differences in the expression of miR-141-3p were observed between hepatocellular carcinoma tissue and normal liver tissue (P = .984). Real-time quantitative polymerase chain reaction confirmed a similar trend of decreased miR-141-3p in hepatocellular carcinoma tissue (1.7542 [0.8663] vs 2.5562 [1.7913], P = .001) as observed in The Cancer Genome Atlas. In addition, decreased miR-141-3p levels were detected in the multiple tumor nodes group (P = .004), the metastasis group (P < .001), and the advanced TNM stage group (P = .01), compared to the single tumor nodes group, the nonmetastasis group, and the early TNM stage group. Two hundred eighty-two genes were identified from the overlap between the predicted targets and the natural language processing analysis. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed several significant biological functions and pathways related to the pathogenesis of cancers, including hepatocellular carcinoma.

CONCLUSION

Downregulation of miR-141-3p might be responsible for the carcinogenesis and aggressiveness of hepatocellular carcinoma. MiR-141-3p may act as an antitumor microRNA, which is essential for hepatocellular carcinoma progression through the regulation of various signaling pathways. Thus, interactions with miR-141-3p may provide a novel strategy for hepatocellular carcinoma treatment in the future.

Lnc-ATB contributes to gastric cancer growth through a MiR-141-3p/TGFβ2 feedback loop

The long noncoding RNA (lncRNA) ATB is an important regulator in human tumors. Here, we aimed to investigate the potential molecular mechanisms of lnc-ATB in gastric cancer (GC) tumorigenesis. RT-qPCR analysis was used to detect lnc-ATB expression level in 20 pairs of gastric cancer tissues and adjacent normal gastric mucosa tissues (ANTs). Moreover, the biological role of lnc-ATB was determined in vitro. We found that lnc-ATB was significantly upregulated in GC tissues compared to lnc-ATB expression in ANTs. These high lnc-ATB expression levels predicted poor prognosis in GC patients. Low levels of lnc-ATB inhibited GC cell proliferation and cell cycle arrest in vitro. Lnc-ATB was found to directly bind miR-141-3p. Moreover, TGF-β actives lnc-ATB and TGF-β2 directly binds mir-141-3p. Finally, we demonstrated that lnc-ATB fulfilled its oncogenic roles in a ceRNA-mediated manner. Our study suggests that lnc-ATB promotes tumor progression by interacting with miR-141-3p and that Lnc-ATB may be a valuable prognostic predictor for GC. In conclusion, the positive feedback loop of lnc-ATB/miR-141-3p/TGF-β2 may be a potential therapeutic target for the treatment of GC.