miR-429 inhibits migration and invasion of breast cancer cells in vitro

miR-429 is involved in regulation of NF-κBactivity by targeting IKKβ and suppresses oncogenic activity in cervical cancer cells

Dysregulation of microRNAs (miRNAs) can contribute to tumorigenesis in cancers. In this study, we found that miR-429 was downregulated in cervical cancer (CC) tissues and suppressed cell viability and proliferation while promoting apoptosis in CC cells. IKKβ was a novel target gene of miR-429 and ectopic expression of IKKβ abrogated the phenotypes induced by miR-429. When IKKβ was downregulated by miR-429, nuclear factor κB (NF-κB) pathway activation, interleukin-6 (IL-6), and interferon-β (IFN-β) production were decreased in CC cells. These findings indicate that miR-429 is involved in regulation of the NF-κB pathway by targeting IKKβ and functions as a tumor suppressor in cervical carcinogenesis.

Profiling of the Predicted Circular RNAs in Ductal In Situ and Invasive Breast Cancer: A Pilot Study

The recent advantage obtained by next generation sequencing allows a depth investigation of a new “old” kind of noncoding transcript, the circular RNAs. Circular RNAs are nontranslated RNAs, typically nonpolyadenylated, with a resistance to exonucleases that gives them the ability to be more stable than the common linear RNA isoforms. We used a bioinformatic detection tool (CIRCexplorer) to research predictive circRNAs from the next generation sequenced data of five samples of ductal in situ carcinoma (DCIS) and matched adjacent invasive ductal carcinoma (IDC). Furthermore, we also investigated the circular RNAs expressed in MCF7, an invasive breast ductal carcinoma cell line. We described the genomic context of the predicted circular RNAs and we address the hypothetical possible functional roles. This study showed a perspective of a panel of predictive circRNAs identified and the function that circRNAs could exert.

MicroRNA Exert Macro Effects on Cancer Bone Metastasis

Bone metastasis is a deadly complication of cancers arising from many different primary tumor locations. Cross talk between cancer and bone cells is a well-established driver of bone metastasis, and recent work reveals microRNA (miRNA) as key players in this communication. Functional significance of miRNA was first demonstrated in cancer cells and has now also been documented in bone cell differentiation and skeletal remodeling. Review of recent literature highlights how different miRNAs can impact each step of the metastatic process by acting in both tumor and the metastatic niche to exert pleiotropic effects. Additionally, whether a miRNA is ultimately pro- or anti-metastatic dependents on the context-varied or even opposite outcomes can be conferred by the same miRNA in different cancer/cell types. In spite of this complexity, emerging research has provided a wealth of knowledge to uncover the exciting potential of miRNA as new diagnostic tools and therapeutic treatments for cancer bone metastasis.

KIAA0101, a target gene of miR-429, enhances migration and chemoresistance of epithelial ovarian cancer cells

Background

Ovarian cancer is a common type of gynecological malignancies, and is the fifth leading cause of cancer-related death in women in the United States. MiR-429 and KIAA0101 have been found to be involved in several human malignancies, respectively. However, the role of miR-429 and KIAA0101, and the correlation between them during development of epithelial ovarian cancer (EOC) remain to be investigated.

Methods

The expression of KIAA0101 in EOC tissues and cells was measured by Quantitative real-time PCR, western blot, and immunochemistry. Cell proliferation assay, colony formation assay, and transwell assay was performed to assess the role of miR-429 and KIAA0101 in regulation of proliferation, migration, and chemoresistance of EOC cells. Luciferase assay was used to test the Wnt/β-catenin signaling activity in response to depletion of KIAA0101 and overexpression of miR-429.

Results

We found that KIAA0101 was upregulated in metastatic EOC tissues, compared to primary EOC tissues, and KIAA0101 was required for the migration activity and chemoresistance of EOC cells by enhancing Wnt/β-catenin signaling. Furthermore, we revealed KIAA0101 is direct target of miR-429. Similar to knockdown of KIAA0101, overexpression of miR-429 reduced invasion and chemoresistance of EOC cells. Co-transfection of KIAA0101 partially abrogates the inhibitory effects on invasion and chemoresistance in EOC cells.

Conclusions

KIAA0101, a target gene of miR-429, was upregulated in the metastatic EOC tissues, and enhanced the migration activity and chemoresistance of EOC cells. Both miR-429 and KIAA0101 may represent the potential therapeutic targets of EOC.

Tumor-suppressing effects of microRNA-429 in human renal cell carcinoma via the downregulation of Sp1

MicroRNA (miR)-429 has been frequently reported to be downregulated in various tumors, including renal cell carcinoma (RCC), nasopharyngeal carcinoma, Ehrlich ascites tumor cells, gastric cancer, non-small cell lung cancer and endometrial endometrioid carcinoma. The present study investigated the effects of miR-429 on human RCC A498 and 786-O cells. Following transfection of cells with miR-429 mimics and scrambled control, MTT, cell migration, cell invasion and luciferase assays were performed. In addition, western blotting was performed in order to assess the expression of specificity protein 1 (Sp1), which was predicted to be a target of miR-429 by TargetScan. The present results revealed that miR-429 inhibited cell proliferation, migration and invasion of 786-O and A498 cells. In addition, the present results demonstrated that miR-429 overexpression downregulated Sp1 protein expression, which provides evidence that miR-429 may directly target Sp1 in RCC. These results suggest that miR-429 may be investigated for use as a predictive marker for early detection of tumor metastasis and blocking RCC cells from becoming invasive.

miR-429 promotes the proliferation of non-small cell lung cancer cells via targeting DLC-1

The microRNA (miR)-200 family has been demonstrated to be associated with the tumorigenesis and progression of multiple types of human cancer, including non-small cell lung cancer (NSCLC). As a member of the miR-200 family, miR-429 was recently identified to have an oncogenic role in NSCLC. However, the role of miR-429 in NSCLC growth as well as the underlying mechanism remains to be fully elucidated. In the present study, NSCLC cell line H1229 was transfected with miR-429 mimic or inhibitor, respectively. It was observed that overexpression of miR-429 led to a significant increase in NSCLC cell proliferation, while knockdown of miR-429 suppressed the proliferation of H1229 cells. Bioinformatic prediction suggested that deleted in liver cancer 1 (DLC-1), a tumor suppressor in NSCLC, was a putative target gene of miR-429. Therefore, a luciferase reporter assay was performed and confirmed that miR-429 was able to bind the 3'-untranslated region of DLC-1 mRNA in H1229 cells. Furthermore, overexpression of miR-429 inhibited the protein expression of DLC-1, while knockdown of miR-429 promoted the protein expression of DLC-1 in NSCLC H1229 cells. In addition, overexpression of DLC-1 not only inhibited H1229 cell proliferation, but also additionally reversed the promoting effect of miR-429 overexpression on H1229 cell proliferation. Based on these findings, the present study suggests that miR-429 may have an oncogenic role in the regulation of cell proliferation via direct inhibition of DLC-1 protein expression in NSCLC cells. Therefore, miR-429 may present a putative therapeutic target for the treatment of NSCLC growth.

The EMT-activator ZEB1 induces bone metastasis associated genes including BMP-inhibitors

Tumor cell invasion, dissemination and metastasis is triggered by an aberrant activation of epithelial-to-mesenchymal transition (EMT), often mediated by the transcription factor ZEB1. Disseminating tumor cells must acquire specific features that allow them to colonize at different organ sites. Here we identify a set of genes that is highly expressed in breast cancer bone metastasis and activated by ZEB1. This gene set includes various secreted factors, e.g. the BMP-inhibitor FST, that are described to reorganize the bone microenvironment. By inactivating BMP-signaling, BMP-inhibitors are well-known to induce osteolysis in development and disease. We here demonstrate that the expression of ZEB1 and BMP-inhibitors is correlated with bone metastasis, but not with brain or lung metastasis of breast cancer patients. In addition, we show that this correlated expression pattern is causally linked, as ZEB1 induces the expression of the BMP-inhibitors NOG, FST and CHRDL1 both by directly increasing their gene transcription, as well as by indirectly suppressing their reduction via miR-200 family members. Consequently, ZEB1 stimulates BMP-inhibitor mediated osteoclast differentiation. These findings suggest that ZEB1 is not only driving EMT, but also contributes to the formation of osteolytic bone metastases in breast cancer.

Downregulation of microRNA-429 protects cardiomyocytes against hypoxia-induced apoptosis by increasing Notch1 expression

Myocardial ischemia is a commonly encountered symptom, chiefly as a result of coronary artery and heart diseases in middle-aged and elderly individuals, with a sudden occurrence and a high morbidity. In some cases, myocardial ischemia may lead to the injury and subsequent death of cardiomyocytes, and may finally culminate in myocardial infarction (MI). MI is the leading cause of sudden death and is associated with a high mortality rate. In this study, we focused on the role of microRNA-429 (miR‑429) in protecting the cardiomyocytes against apoptosis induced by myocardial ischemia. The culture of human cardiomyocytes under hypoxic conditions was employed to mimic myocardial ischemia. miR‑429 expression was upregulated following culture under hypoxic conditions. Subsequently, miR‑429 was artificially overexpressed and silenced by transfection with miRNA-mimics and miRNA-inhibitor, respectively. The results revealed that the downregulation of miR-429 expression exerts protective effects against hypoxia-induced apoptosis. Moreover, Notch1 was also proven to be involved in these protective effects. The downregulation of miR‑429 was accompanied by the activation of Notch1, as indicated by the significant increase in the protein expression of Notch1. The ectopic expression of Notch1 also inhibited the apoptosis induced by culture under hypoxic conditions. In conclusion, and to the best of our knowledge, our results demonstrate for the first time that the downregulation of miR‑429 protects cardiomyocytes against hypoxia-induced apoptosis through Notch1; this may provide the experimental basis for an underlying therapeutic target for myocardial ischemia and consequent MI, as well as the basis for an effective preventive treatment against sudden death.

Construction of an initial microRNA regulation network in breast invasive carcinoma by bioinformatics analysis

INTRODUCTION

microRNAs (miRNA) are involved in many biological processes. They repress target gene expression and play a vital role in breast invasive carcinoma (BRCA). Although many miRNAs are identified to be aberrantly expressed in BRCA and deemed as tumor markers, only sporadic individual studies report their target genes and the pathways involved.

METHODS

miRNA and mRNA expression data were collected from the Cancer Genome Atlas (TCGA) pilot project. Aberrantly expressed miRNAs and mRNAs in BRCA were identified by comparing tumor samples with normal adjacent tissues. Differentially expressed miRNAs and mRNAs in different breast cancer subtypes were also analyzed. miRNA/target correlations were predicted by calculating the spearman correlation coefficients between miRNA and mRNA, and validated by luciferase assay.

RESULTS

31 up-regulated miRNAs, 37 down-regulated miRNAs, 1105 up-regulated mRNAs and 1222 down-regulated mRNAs were identified in BRCA; 125 miRNA/target correlations were predicted, 6 of them were validated. In addition, we also found 9 miRNAs and 143 mRNAs differently expressed between estrogen receptor positive and negative breast cancers, and 4 miRNAs and 46 mRNAs differently expressed between progesterone receptor positive and negative breast cancers. Twelve miRNA/target correlations determined the breast cancer subtypes.

CONCLUSION

We developed a new systematic analytic method for analyzing TCGA database, which took into account both miRNA and mRNA data to dissect the miRNA regulation network in BRCA.

miR-429 functions as a tumor suppressor by targeting FSCN1 in gastric cancer cells

It has been previously reported that the deregulation of microRNAs in gastric cancer (GC) was correlated with the progression and prognosis. miR-429, a member of the miR-200 family, was previously shown to play an important role in human carcinomas. Our study shows that miR-429 is significantly downregulated in GC tissues compared with matched nontumor tissues. Overexpression of miR-429 in GC cells suppressed cell proliferation. Fascin-1 (FSCN1) was identified as one of the targets of miR-429 and knockdown of FSCN1 mimics the function of miR-429 overexpression. In conclusion, miR-429 acts as a tumor suppressor by targeting FSCN1, suggesting that miR-429 and FSCN1 can both be potential therapeutic targets of GC.

Downregulation of miR‑429 and inhibition of cell migration and invasion in nasopharyngeal carcinoma

Viral, dietary and genetic factors have been implicated in nasopharyngeal carcinoma (NPC), however, the molecular mechanism underlying its pathogenesis remains to be fully elucidated. MicroRNAs (miRNAs) have been reported to be important in NPC tumorigenesis, with a previous miRNA microarray study showing the downregulation of miRNA (miR)‑429 in NPC cells. However, the possible mechanisms of action of miR‑429 have not been examined. In the present study, the expression profiles of miR‑429 were detected using reverse transcription‑quantitative polymerase chain reaction analysis in CNE‑1 and CNE‑2 cells, which are two generally used NPC cells with different degrees of differentiation. Subsequently, cell proliferation, invasion and migration were analyzed in miR‑429‑overexpressing CNE‑2 cells, and the modulatory function of miR‑429 was also investigated using two target genes, zinc finger E‑Box‑binding homeobox 1 (ZEB1) and CRK‑like (CRKL), by transfection with miR‑429 mimic or anti‑miR‑429. Significant changes in the expression of miR‑429 were detected, particularly in low‑differentiated CNE‑2 cells, with higher levels of epidemicity and malignancy. Additional results revealed that miR‑429 inhibited the invasion and migration of the CNE‑2 cells, whereas no significant effect on cell growth was observed. In addition, the mRNA and protein expression levels of the two target genes, ZEB1 and CRKL, were negatively regulated by miR‑429, demonstrated through gain‑of‑function and loss‑of‑function investigations, indicating that these two functional downstream targets may be involved in the inhibitory effects of miR‑429 on NPC migration and invasion. miR‑429 may act as a negative regulatory factor of NPC tumorigenesis, involving the functions of its downstream targets, ZEB1 and CRKL. The results suggested miR‑429 as a potential candidate for miRNA‑based prognosis or therapy against NPC.

Metastatic breast cancer: the potential of miRNA for diagnosis and treatment monitoring

Breast cancer affects approximately 12 % women worldwide and results in 14 % of all cancer-related fatalities. Breast cancer is commonly categorized into one of four main subtypes (luminal A, luminal B, human epidermal growth factor receptor 2 (HER2) positive and basal), indicating molecular characteristics and informing treatment regimes. The most severe form of breast cancer is metastasis, when the tumour spreads from the breast tissue to other parts of the body. Significantly, the primary tumour subtype affects rates and sites of metastasis. Currently, up to 5 % of patients present with incurable metastasis, with an additional 10–15 % of patients going on to develop metastasis within 3 years of diagnosis. MicroRNAs (miRNAs) are short 21–25 long nucleotides that have been shown to significantly affect gene expression. Currently, >2000 miRNAs have been identified and significantly, specific miRNAs have been found associated with diseases states. Importantly, miRNAs are found circulating in the blood, presenting an opportunity to use these circulating disease-related miRNAs as biomarkers. Clearly, the identification of circulating miRNA specific to metastatic breast cancer presents a unique opportunity for early disease identification and for monitoring disease burden. Currently however, few groups have identified miRNA associated with metastatic breast cancer. Here, we review the literature surrounding the identification of metastatic miRNA in breast cancer patients, highlighting key areas where miRNA biomarker discovery could be beneficial, identifying key concepts, recognizing critical areas requiring further research and discussing potential problems.

Diagnostic and prognostic potential of serum miR-7, miR-16, miR-25, miR-93, miR-182, miR-376a and miR-429 in ovarian cancer patients

Background:

Owing to late diagnosis in advanced disease stages, prognosis of patients with epithelial ovarian cancer (EOC) is poor. The quantification of deregulated levels of microRNAs could facilitate earlier diagnosis and improve prognosis of EOC.

Methods:

Seven microRNAs (miR-7, miR-16, miR-25, miR-93, miR-182, miR-376a and miR-429) were quantified in the serum of 180 EOC patients and 66 healthy women by TaqMan PCR microRNA assays. Median follow-up time was 21 months. The effects of miR-7 and miR-429 on apoptosis, cell proliferation, migration and invasion were investigated in two (EOC) cell lines.

Results:

Serum levels of miR-25 (P=0.0001) and miR-93 (P=0.0001) were downregulated, whereas those of miR-7 (P=0.001) and miR-429 (P=0.0001) were upregulated in EOC patients compared with healthy women. The four microRNAs discriminated EOC patients from healthy women with a sensitivity of 93% and a specificity of 92%. The levels of miR-429 positively correlated with CA125 values (P=0.0001) and differed between FIGO I–II and III–IV stages (P=0.001). MiR-429 was an independent predictor of overall survival (P=0.011). Overexpressed miR-429 in SKOV3 cells led to suppression of cell migration (P=0.037) and invasion (P=0.011). Increased levels of miR-7 were associated with lymph node metastases (P=0.0001) and FIGO stages III–IV (P=0.0001). Overexpressed miR-7 in SKOV3 cells resulted in increased cell migration (P=0.001) and invasion (P=0.011). Additionally, the increased levels of miR-376a correlated with FIGO stages III–IV (P=0.02).

Conclusions:

Our data indicate the diagnostic potential of miR-7, miR-25, miR-93 and miR-429 in EOC and the prognostic potential of miR-429. This microRNA panel may be promising molecules to be targeted in the treatment of EOC.

The role of CRKL in breast cancer metastasis: insights from systems biology

Breast cancer metastasis is a complex and still weakly understood process that involves diverse cellular pathways. It accounts for the majority of deaths from breast cancer. Recently, microRNAs (miRNAs), small non-coding RNAs that regulate gene expression post-transcriptionally, have been shown to be involved in breast cancer metastasis. In particular, in a recent work it has been found that miR-429 may have a role in the inhibition of migration and invasion of breast cancer cells. Its target gene CRKL has been identified as a potential candidate. In this paper, by using systems biology tools we have shown that CRKL is involved in positive regulation of ERK1/2 signaling pathway and contribute to the regulation of LYN through a topological generalization of feed forward loop.

MicroRNA-429 suppresses cell proliferation, epithelial-mesenchymal transition, and metastasis by direct targeting of BMI1 and E2F3 in renal cell carcinoma

BACKGROUND

MicroRNA-429 (miR-429), a short noncoding RNA belonging to the miR-200 superfamily, plays a crucial role in tumorigenesis and tumor progression. It also acts as a modulator of epithelial-to-mesenchymal transition, a cell development regulating process that affects tumor development and metastasis. The aim of this study was to investigate the potential role of miR-429 in regulating growth and metastasis of renal cell carcinoma.

METHODS

miR-429 expression was stably up-regulated or down-regulated in the renal cell carcinoma ACHN and A498 cell lines, and cell proliferation and metastasis were assessed.

RESULTS

miR-429 overexpression inhibited cell proliferation, colony formation, migration, and invasion. Suppression of endogenous miR-429 promoted cell growth and metastasis. miR-429 was shown to directly target the 3' untranslated regions of B-cell-specific Moloney murine leukemia virus insertion site 1 (BMI1) and E2F transcription factor 3 (E2F3) transcripts, regulating their expression, as well as that of the downstream epithelial-to-mesenchymal transition markers E-cadherin, N-cadherin, vimentin, p14, and p16.

CONCLUSIONS

These results revealed a tumor suppressive role for miR-429 in renal cell carcinoma through directly targeting BMI1 and E2F3.

microRNA-214 enhances the invasion ability of breast cancer cells by targeting p53

Breast cancer (BC) is the foremost cause of cancer-related mortality in women worldwide. An increasing number of studies has confirmed that microRNAs (miRNAs or miRs) play an important role in the development and progression of BC. microRNA-214 (miR-214), a member of the miRNA family, has been demonstrated to function as both a tumor suppressor and oncogene in various types of human cancer. However, the biological function of miR-214 in BC remains unclear. The present study was designed to investigate the potential role of miR-214 in the development and progression of BC. Our results revealed that miR-214 expression was significantly increased in the BC tissues compared with the adjacent benign tissues, and that the upregulation of miR-214 was significantly associated with the invasion ability of the BC cells. Furthermore, p53, which has been reported to be downregulated in BC, was predicted to be the target gene of miR-214 using bioinformatics software programs. Moreover, luciferase reporter vectors were constructed and it was confirmed that p53 is a target of miR-214. Following the transfection of miR-214 into BC cells, we found that the overexpression of miR-214 markedly enhanced cell invasion through the downregulation of p53 expression. By contrast, the overexpression of p53 abrogated the effects of miR-214. In conclusion, this study demonstrates that miR-214 functions as an oncogene in BC, at least partly by promoting cell invasion through the downregulation of p53. Therefore, miR-214 may be a potential therapeutic target for the treatment of BC.