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

Low-dose Lipopolysaccharide Alleviates Spinal Cord Injury-induced Neuronal Inflammation by Inhibiting microRNA-429-mediated Suppression of PI3K/AKT/Nrf2 Signaling

This study investigated the impact of low-dose lipopolysaccharide (LPS) on spinal cord injury (SCI) and the potential molecular mechanism. Rats were randomly assigned to four groups: Sham, SCI, SCI + LPS, and SCI + LPS + agomir. Allen's weight-drop method was used to establish an in vivo SCI model. The Basso Bcattie Bresnahan rating scale was employed to monitor locomotor function. An in vitro SCI model was constructed by subjecting PC12 cells to oxygen and glucose deprivation/ reoxygenation (OGD/R). Enzyme-linked immunosorbent assay (ELISA) was applied for the determination interleukin (IL)-1β and IL-6. The dual luciferase reporter assay was used to validate the targeting of microRNA (miR)-429 with PI3K. Immunohistochemical staining was used to assess the expression of PI3K, phosphorylated AKT and Nrf2 proteins. The Nrf2-downstream anti-oxidative stress proteins, OH-1 and NQO1, were detected by western blot assay. MiR-429 expression was detected by fluorescence in situ hybridization and real-time quantitative reverse transcription PCR. In vitro, low-dose LPS decreased miR-429 expression, activated PI3K/AKT/Nrf2, inhibited oxidative stress and inflammation, and attenuated SCI. MiR-429 was found to target and negatively regulate PI3K. Inhibition of miR-429 suppressed low-dose LPS-mediated oxidative stress and inflammation via activation of the PI3K/AKT/Nrf2 pathway. In vivo, miR-429 was detectable in neurons. Inhibition of miR-429 blocked low-dose LPS-mediated oxidative stress and inflammation via activation of the PI3K/AKT/Nrf2 pathway. Overall, low-dose LPS was found to alleviate SCI-induced neuronal oxidative stress and inflammatory response by down-regulating miR-429 to activate the PI3K/AKT/Nrf2 pathway.

miR-429 Suppresses Endometrial Cancer Progression and Drug Resistance via DDX53

(1) Background: To examine miR-429-meditated DEAD (Asp-Glu-Ala-Asp) box polypeptide 53 (DDX53) function in endometrial cancer (EC). (2) Methods: DDX53 and miR-429 levels were measured using quantitative real-time polymerase chain reaction and western blotting assays, cell invasion and migration using Transwell invasion and wound healing assays, and cell proliferation using colony-forming/proliferation assays. A murine xenograft model was also generated to examine miR-429 and DDX53 functions in vivo. (3) Results: DDX53 overexpression (OE) promoted key cancer phenotypes (proliferation, migration, and invasion) in EC, while in vivo, DDX53 OE hindered tumor growth in the murine xenograft model. Moreover, miR-429 was identified as a novel miRNA-targeting DDX53, which suppressed EC proliferation and invasion. (4) Conclusions: DDX53 and miR-429 regulatory mechanisms could provide novel molecular therapies for EC.

Long noncoding RNA ZEB1-AS1 attenuates ferroptosis of gastric cancer cells through modulating miR-429/BGN axis

Gastric cancer (GC) is the fifth utmost common malignant cancer type globally, in which ferroptosis acts a critical function in the progress of GC. Long noncoding RNA ZEB1-AS1 has been recognized in numerous cancers, but the role of ZEB1-AS1 in ferroptosis remains obscure. Hence, we investigated the efficacy of ZEB1-AS1 on ferroptosis of GC cells. The cell growth and viability were analyzed via cell counting kit assay and xenograft tumor model in vivo and in vitro, respectively. The RNA and protein expression were measured by qRT-PCR and western blot analysis assay, respectively. The levels of Fe2+ , malondialdehyde (MDA), and lipid reactive oxygen species (ROS) were tested to determine ferroptosis. The erastin and RSL3 were used to induce ferroptosis. The mechanism was analyzed via luciferase reporter gene and RIP assays. The treatment of ferroptosis inducer Erastin and RSL3 suppressed the viability of GC cells and the ZEB1-AS1 overexpression rescued the phenotype in the cells. The levels of Fe2+ , MDA, and ROS were enhanced through the depletion of ZEB1-AS1 in Erastin/RSL3 treated GC cells. ZEB1-AS1 directly sponged miR-429 in GC cells and miR-429 targeted BGN in GC cells, and the inhibition of miR-429 rescued ZEB1-AS1 depletion-inhibited BGN expression. We validated that miR-429 induced and BGN-repressed ferroptosis in cancer cells. The BGN overexpression and miR-429 suppression could reverse the efficacy of ZEB1-AS1 on proliferation and ferroptosis in cancer cells. The expression of ZEB1-AS1 and BGN was enhanced and miR-429 expression was decreased in clinical GC tissues. ZEB1-AS1 attenuated ferroptosis of cancer cells by modulating miR-429/BGN axis.

Exosomal miRNAs as novel avenues for breast cancer treatment

Breast cancer is the most commonly diagnosed cancer and a leading cause of death in women worldwide. It is a heterogeneous disease, as shown by the gene expression profiles of breast cancer samples. It begins in milk-producing ducts, with a high degree of diversity between and within tumors, as well as among cancer-bearing individuals. The enhanced prevalence of breast cancer is influenced by various hormonal, lifestyle, and environmental factors, and very early onset of the disease correlates strongly with the risk of local and distant recurrence. Many subtypes are difficult to treat with conventional therapeutic modalities, and therefore, optimal management and early diagnosis are the first steps to minimizing the mortality linked with breast cancer. The use of newer methods of nanotechnology extends beyond the concept of synthesizing drug delivery mechanisms into the creation of new therapeutics, such as delivering chemotherapeutics with nanomaterial properties. Exosomes, a class of nanovesicles, are emerging as novel tools for deciphering the patient-specific proteins and biomarkers across different disease models, including breast cancer. In this review, we address the role of exosomal miRNA in breast cancer diagnosis and treatment.

Meso-Hannokinol inhibits breast cancer bone metastasis via the ROS/JNK/ZEB1 axis

Distal metastases from breast cancer, especially bone metastases, are extremely common in the late stages of the disease and are associated with a poor prognosis. EMT is a biomarker of the early process of bone metastasis, and MMP-9 and MMP-13 are important osteoclastic activators. Previously, we found that meso-Hannokinol (HA) could significantly inhibit EMT and MMP-9 and MMP-13 expressions in breast cancer cells. On this basis, we further explored the role of HA in breast cancer bone metastasis. In vivo, we established a breast cancer bone metastasis model by intracardially injecting breast cancer cells. Intraperitoneal injections of HA significantly reduced breast cancer cell metastasis to the leg bone in mice and osteolytic lesions caused by breast cancer. In vitro, HA inhibited the migration and invasion of breast cancer cells and suppressed the expressions of EMT, MMP-9, MMP-13, and other osteoclastic activators. HA inhibited EMT and MMP-9 by activating the ROS/JNK pathway as demonstrated by siJNK and SP600125 inhibition of JNK phosphorylation and NAC scavenging of ROS accumulation. Moreover, HA promoted bone formation and inhibited bone resorption in vitro. In conclusion, our findings suggest that HA may be an excellent candidate for treating breast cancer bone metastasis.

CircLIFR Inhibits Non-small Cell Lung Cancer Progression by Acting as a miR-429 Sponge to Enhance CELF2 Expression

Lung cancer is the most commonly diagnosed cancer and the leading reason for tumor-related mortality, while non-small cell lung cancer (NSCLC) is the most usual type of lung cancer. Circular RNAs (circRNAs) have emerged as vital regulators in the development of human cancers, including NSCLC. We aimed to explore the functions of circRNA leukemia inhibitory factor receptor (circLIFR) in NSCLC progression. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to quantify the expression of circLIFR, microRNA-429 (miR-429), and Elav-like family member 2 (CELF2) in NSCLC tissues and cells. Cell proliferation capability of NSCLC cells was determined by Cell Counting Kit-8 (CCK-8) and colony formation assays. The flow cytometry assay was performed to evaluate cell-cycle distribution and apoptosis of NSCLC cells. The abilities of migration and invasion were measured by transwell assay. In addition, the activities of caspase 3 and caspase 9 were measured by the assay kits. The interaction relationship between miR-429 and circLIFR or CELF2 was analyzed by dual-luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays. The expression levels of related proteins were examined by Western Blot assay. The xenograft experiment was established to explore the role of circLIFR in vivo. CircLIFR, circular, and stable transcript in NSCLC cells, was decreased more than 2 folds in NSCLC tissues and cells than controls (P < 0.0001). Importantly, overexpression of circLIFR impeded cell proliferation, migration, invasion, and inactivated protein kinase B (AKT)/phosphatase and tensin homolog (PTEN)-signaling pathways while enhanced apoptosis and cell-cycle arrest in NSCLC cells, which was overturned by upregulation of miR-429 or silencing of CELF2. Furthermore, the upregulation of circLIFR inhibited NSCLC tumor growth in vivo. Overexpression of circLIFR could suppress NSCLC progress by acting as a sponge of miR-429 to regulate the expression of CELF2 and PTEN/AKT-signaling pathways in NSCLC.

MicroRNAs as therapeutic targets in breast cancer metastasis

Breast cancer is a complex disease with multiple risk factors involved in its pathogenesis. Among these factors, microRNAs are considered for playing a fundamental role in the development and progression of malignant breast tumors. In recent years, various studies have demonstrated that several microRNAs exhibit increased or decreased expression in metastatic breast cancer, acting as indicators of metastatic potential in body fluids and tissue samples. The identification of these microRNA expression patterns could prove instrumental for the development of novel therapeutic molecules that either mimic or inhibit microRNA action. Additionally, an efficient delivery system mediated by viral vectors, nonviral carriers, or scaffold biomaterials is a prerequisite for implementing microRNA-based therapies; therefore, this review attempts to highlight essential microRNA molecules involved in the metastatic process of breast cancer and discuss recent advances in microRNA-based therapeutic approaches with potential future applications to the treatment sequence of breast cancer.

MAPKAPK5-AS1 drives the progression of hepatocellular carcinoma via regulating miR-429/ZEB1 axis

Background

Hepatocellular carcinoma (HCC) is a common malignancy. Long non-coding RNAs (lncRNAs) partake in the progression of HCC. However, the role of lncRNA MAPKAPK5-AS1 in the development of HCC has not been fully clarified.

Methods

RNA sequencing data and quantitative real-time polymerase chain reaction (qRT-PCR) were adopted to analyze MAPKAPK5-AS1, miR-429 and ZEB1 mRNA expressions in HCC tissues and cell lines. Western blot was used to detect ZEB1, E-cadherin and N-cadherin protein expressions. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Transwell and flow cytometry assays were adopted to analyze the effects of MAPKAPK5-AS1 on cell proliferation, migration, invasion and apoptosis. Besides, luciferase reporter assay was used to detect the targeting relationship between miR-429 and MAPKAPK5-AS1 or ZEB1 3’UTR. The xenograft tumor mouse models were used to explore the effect of MAPKAPK5-AS1 on lung metastasis of HCC cells.

Results

MAPKAPK5-AS1 and ZEB1 expressions were up-regulated in HCC tissues, and miR-429 expression is down-regulated in HCC tissues. MAPKAPK5-AS1 knockdown could significantly impede HCC cell proliferation, migration, invasion and epithelial-mesenchymal transition (EMT), as well as promote cell apoptosis. MAPKAPK5-AS1 overexpression could enhance L02 cell proliferation, migration, invasion and EMT, and inhibit cell apoptosis. MiR-429 was validated to be the target of MAPKAPK5-AS1, and miR-429 inhibitors could partially offset the effects of knocking down MAPKAPK5-AS1 on HCC cells. MAPKAPK5-AS1 could positively regulate ZEB1 expression through repressing miR-429. Moreover, fewer lung metastatic nodules were observed in the lung tissues of nude mice when the MAPKAPK5-AS1 was knocked down in HCC cells.

Conclusion

MAPKAPK5-AS1 can adsorb miR-429 to promote ZEB1 expression to participate in the development of HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12860-022-00420-x.

δ-tocotrienol suppresses the migration and angiogenesis of trophoblasts in preeclampsia and promotes their apoptosis via miR-429/ ZEB1 axis

Preeclampsia (PE) is a severe medical disorder during pregnancy and there has been controversy about the effects of vitamin E on PE. This research intended to explore if δ-tocotrienol (δ-TT), an isomer of vitamin E, could impact PE. Preeclamptic and normal placentas were obtained and total RNA was extracted. The expression of different genes was analyzed through quantitative real-time polymerase chain reaction (qRT-PCR) and Pearson correlation analysis was conducted. After that, HTR-8/SVneo cells (human trophoblasts) were chosen and they were subjected to δ-tocotrienol treatment and then Cell Counting Kit-8 was used to test cell viability. To assess the effects of δ-TT on trophoblasts, wound healing assay and Transwell invasion assay were performed. How miR-429 interacts with ZEB1 was examined via dual luciferase reporter assay. Also, protein expression was evaluated via Western blotting. Our results have shown that δ-TT can impair the viability of trophoblasts and induce their apoptosis. Additionally, it can repress the growth, migration, epithelial-mesenchymal transition (EMT), invasion and angiogenesis in trophoblasts. Mechanistically, δ-TT exerts these effects on trophoblasts via downregulating miR-429 and upregulating ZEB1. Furthermore, miR-429 can bind ZEB1 directly. Clinical sample analysis has revealed that miR-429 expression in preeclamptic placenta is higher than that in normal placenta, but ZEB1 expression in preeclamptic placenta is downregulated. Also, there is a negative association between miR-429 and ZEB1 expression in preeclamptic placentas. These discoveries imply that δ-TT may be hazardous to pregnancy and should not be used in preeclamptic patients. In addition, targeting miR-429 might treat PE.

RHO GTPase-Related Long Noncoding RNAs in Human Cancers

RHO GTPases are critical signal transducers that regulate cell adhesion, polarity, and migration through multiple signaling pathways. While all these cellular processes are crucial for the maintenance of normal cell homeostasis, disturbances in RHO GTPase-associated signaling pathways contribute to different human diseases, including many malignancies. Several members of the RHO GTPase family are frequently upregulated in human tumors. Abnormal gene regulation confirms the pivotal role of lncRNAs as critical gene regulators, and thus, they could potentially act as oncogenes or tumor suppressors. lncRNAs most likely act as sponges for miRNAs, which are known to be dysregulated in various cancers. In this regard, the significant role of miRNAs targeting RHO GTPases supports the view that the aberrant expression of lncRNAs may reciprocally change the intensity of RHO GTPase-associated signaling pathways. In this review article, we summarize recent advances in lncRNA research, with a specific focus on their sponge effects on RHO GTPase-targeting miRNAs to crucially mediate gene expression in different cancer cell types and tissues. We will focus in particular on five members of the RHO GTPase family, including RHOA, RHOB, RHOC, RAC1, and CDC42, to illustrate the role of lncRNAs in cancer progression. A deeper understanding of the widespread dysregulation of lncRNAs is of fundamental importance for confirmation of their contribution to RHO GTPase-dependent carcinogenesis.

ln RNA LINC01234 promotes triple-negative breast cancer progression through regulating the miR-429/SYNJ1 axis

Emerging evidence has illustrated that long noncoding RNA 01234 (LINC01234) has played a pivotal role in the development and progression of human cancer. The regulatory role and underlying mechanisms of LINC01234 in triple-negative breast cancer (TNBC) remains unknown. In this study, we analyzed the expression level of LINC01234 in several breast cancer cell lines. CCK-8, EdU, flow cytometry analysis, wound healing assay, and transwell assay were carried out to investigate the effect of LINC01234 on tumor proliferation, apoptosis, and migration. Bioinformatic analysis and luciferase reporter assays were performed to confirm the molecular binding. We found that LINC01234 was dramatically upregulated in breast cancer cell lines, especially in TNBC. The loss and gain-of functional experiments revealed that LINC01234 significantly promoted proliferation, migration, and suppressed cell apoptosis of MDA-MB-231 cells in vitro and inhibited tumorigenesis in vivo. Mechanistic investigations demonstrated that LINC01234 might act as a competing endogenous RNA (ceRNA) for miR-429 to regulate the SYNJ1 expression. The effects of miR-429 and SYNJ1 in MDA-MB-231 cells were also analyzed. Our results revealed that the novel LINC01234/miR-429/SYNJ1 axis played a critical role in progression of TNBC cell line MDA-MB-231, and it may serve as a therapeutic target for TNBC.

LINC00894 Enhances the Progression of Breast Cancer by Sponging miR-429 to Regulate ZEB1 Expression

PURPOSE

Long non-coding RNAs (lncRNAs) are known to regulate tumorigenesis. Although breast cancer tissues show a high expression of LINC00894, its specific biological role in breast cancer progression is still unknown. In this study, lncRNA microarray was used to analyze the lncRNA expression in breast cancer tissues, and LINC00894 was selected for further analysis.

MATERIALS AND METHODS

Expression of LINC00894 in 45 pairs of breast cancer tissues and normal tissues obtained from patients with breast cancer was assessed by quantitative reverse transcription-PCR, while proliferation and invasion of breast cancer cells were assessed using a Cell Counting Kit-8 (CCK-8), EdU assay, colony formation experiment, and transwell assays. A dual-luciferase reporter gene assay and bioinformatics analysis were employed to detect potential targets of LINC00894. Additionally, RNA Binding Protein Immunoprecipitation (RIP) and Western blot assays were utilized to clarify its interaction and roles in the regulation of breast cancer progression.

RESULTS

High expression of LINC00894 was observed in breast cancer cells, and its overexpression significantly expedited cell proliferation and invasion. Moreover, LINC00894 positively regulated the expression of ZEB1 by competitively binding to miR-429.

CONCLUSION

Taken together, these results suggest that LINC00894 competitively binds to miR-429 to mediate ZEB1 expression; consequently, it is implicated to play a role in the progression of breast cancer.

Exosomal transfer of miR-429 confers chemoresistance in epithelial ovarian cancer

The development of multidrug resistance during chemotherapy is the main obstacle for epithelial ovarian cancer (EOC) treatment. Exosomal transfer of carcinogenic microRNAs (miRNAs) might strengthen chemoresistance in recipient cells. Here, we identified through microarray analysis higher miR-429 expression in multidrug-resistant SKOV3 cells and their secreted exosomes (SKOV3-EXO) than in sensitive A2780 cells and their secreted exosomes. SKOV3-derived exosomes were internalized by A2780 cells, which permitted the transfer of miR-429. Exosomal miR-429 enhanced the proliferation and drug resistance of A2780 cells by targeting calcium-sensing receptor (CASR)/STAT3 pathway in vitro and in vivo. In addition, NF-κB-p65 was predicted to bind to the miR-429 promoter region, and the inhibition of NF-κB reduced the expression of miR-429 and led to the sensitivity of EOC cells. Consistently, A2780 cells co-incubated with SKOV3 pretreated with an NF-κB inhibitor or miR-429 antagomir showed sensitivity to cisplatin and exhibited attenuated cell proliferation. Based on our data, exosomal miR-429 functions as a primary regulator of the chemoresistance and malignant phenotypes of EOC by targeting CASR through a mechanism promoted by NF-κB and might be a therapeutic target for EOC.

Exosomal microRNAs: Pleiotropic Impacts on Breast Cancer Metastasis and Their Clinical Perspectives

As a major threat factor for female health, breast cancer (BC) has garnered a lot of attention for its malignancy and diverse molecules participating in its carcinogenesis process. Among these complex carcinogenesis processes, cell proliferation, epithelial-to-mesenchymal transition (EMT), mesenchymal-to-epithelial transition (MET), and angiogenesis are the major causes for the occurrence of metastasis and chemoresistance which account for cancer malignancy. MicroRNAs packaged and secreted in exosomes are termed "exosomal microRNAs (miRNAs)". Nowadays, more researches have uncovered the roles of exosomal miRNAs played in BC metastasis. In this review, we recapitulated the dual actions of exosomal miRNAs exerted in the aggressiveness of BC by influencing migration, invasion, and distant metastasis. Next, we presented how exosomal miRNAs modify angiogenesis and stemness maintenance. Clinically, several exosomal miRNAs can govern the transformation between drug sensitivity and chemoresistance. Since the balance of the number and type of exosomal miRNAs is disturbed in pathological conditions, they are able to serve as instructive biomarkers for BC diagnosis and prognosis. More efforts are needed to connect the theoretical studies and clinical traits together. This review provides an outline of the pleiotropic impacts of exosomal miRNAs on BC metastasis and their clinical implications, paving the way for future personalized drugs.

Interplay between p53 and non-coding RNAs in the regulation of EMT in breast cancer

The epithelial-mesenchymal transition (EMT) plays a pivotal role in the differentiation of vertebrates and is critically important in tumorigenesis. Using this evolutionarily conserved mechanism, cancer cells become drug-resistant and acquire the ability to escape the cytotoxic effect of anti-cancer drugs. In addition, these cells gain invasive features and increased mobility thereby promoting metastases. In this respect, the process of EMT is critical for dissemination of solid tumors including breast cancer. It has been shown that miRNAs are instrumental for the regulation of EMT, where they play both positive and negative roles often as a part of a feed-back loop. Recent studies have highlighted a novel association of p53 and EMT where the mutation status of p53 is critically important for the outcome of this process. Interestingly, p53 has been shown to mediate its effects via the miRNA-dependent mechanism that targets master-regulators of EMT, such as Zeb1/2, Snail, Slug, and Twist1. This regulation often involves interactions of miRNAs with lncRNAs. In this review, we present a detailed overview of miRNA/lncRNA-dependent mechanisms that control interplay between p53 and master-regulators of EMT and their importance for breast cancer.

Characterisation of the novel spontaneously immortalized and invasively growing human skin keratinocyte line HaSKpw

We here present the spontaneously immortalised cell line, HaSKpw, as a novel model for the multistep process of skin carcinogenesis. HaSKpw cells were established from the epidermis of normal human adult skin that, without crisis, are now growing unrestricted and feeder-independent. At passage 22, clonal populations were established and clone7 (HaSKpwC7) was further compared to the also spontaneously immortalized HaCaT cells. As important differences, the HaSKpw cells express wild-type p53, remain pseudodiploid, and show a unique chromosomal profile with numerous complex aberrations involving chromosome 20. In addition, HaSKpw cells overexpress a pattern of genes and miRNAs such as KRT34, LOX, S100A9, miR21, and miR155; all pointing to a tumorigenic status. In concordance, HaSKpw cells exhibit reduced desmosomal contacts that provide them with increased motility and a highly migratory/invasive phenotype as demonstrated in scratch- and Boyden chamber assays. In 3D organotypic cultures, both HaCaT and HaSKpw cells form disorganized epithelia but only the HaSKpw cells show tumorcell-like invasive growth. Together, HaSKpwC7 and HaCaT cells represent two spontaneous (non-genetically engineered) “premalignant” keratinocyte lines from adult human skin that display different stages of the multistep process of skin carcinogenesis and thus represent unique models for analysing skin cancer development and progression.

LncRNA OIP5-AS1 promotes the malignancy of pancreatic ductal adenocarcinoma via regulating miR-429/FOXD1/ERK pathway

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC), a subtype of pancreatic cancer, is a malignant tumor with unfavorable prognosis. Despite accumulating researches have made efforts on finding novel therapeutic methods for this disease, the underlying mechanism of long non-coding RNAs (lncRNAs) remains elusive. OIP5 antisense RNA 1 (OIP5-AS1) has been reported to play important role in the occurrence and development of multiple human cancers. This study was aimed at unveiling the regulatory role of OIP5-AS1 in PDAC.

METHODS

RT-qPCR analysis revealed the OIP5-AS1 expression in PDAC tissues and adjacent normal ones. Kaplan-Meier method was applied to analyze the overall survival of patients with high or low level of OIP5-AS1. Gain- or loss-of function assays were performed to assess the effects of OIP5-AS1 knockdown on cell functions, including proliferation, migration and EMT process. Mechanism experiments, such as luciferase reporter and RNA pull-down assays proved the interaction between OIP5-AS1 and miR-429 as well as that between miR-429 and FOXD1.

RESULTS

OIP5-AS1 was up-regulated in PDAC tissues and cell lines, and high level of OIP5-AS1 indicated poor prognosis in PDAC patients. OIP5-AS1 knockdown hindered cell proliferation, migration and epithelial-mesenchymal transition (EMT) process, while overexpression of OIP5-AS1 caused the opposite results. OIP5-AS1 activated ERK pathway through up-regulating forkhead box D1 (FOXD1) expression by sponging miR-429. Furthermore, OIP5-AS1 facilitated cell growth in vivo.

CONCLUSION

OIP5-AS1 exerted oncogenic function in PDAC cells through targeting miR-429/FOXD1/ERK pathway.

miR-429-CRKL axis regulates clear cell renal cell carcinoma malignant progression through SOS1/MEK/ERK/MMP2/MMP9 pathway

The pathogenesis and tumorigenesis of clear cell renal cell carcinoma (ccRCC) remain unclear. The deregulations of miR-429, a member of miR-200 family, and v-crk sarcoma virus CT10 oncogene homologue (avian)-like (CRKL), an adaptor protein of CRK family, are involved in the development, metastasis and prognosis of various cancers. Current study aimed to demonstrate the differential expressions of miR-429 and CRKL with their correlationship and molecular regulation mechanism in ccRCC malignancy. miR-429 and CRKL separately showed suppressing and promoting effects in ccRCC. Lower miR-429 expression and higher CRKL expression were negatively correlated in surgical cancerous tissues by promoting the advance of ccRCC. By binding to the 3'-UTR of CRKL, miR-429 reversely regulated CRKL for its functionalities in ccRCC cells. CRKL knockdown and overexpression separately decreased and increased the in vitro migration and invasion of 786-O cells, which were consistent with the influences of miR-429 overexpression and knockdown on 786-O through respectively downregulating and upregulating CRKL via SOS1/MEK/ERK/MMP2/MMP9 pathway. The enhancements of CRKL expression, migration and invasion abilities and SOS1/MEK/ ERK/MMP2/MMP9 activation induced by TGF-β stimulation in 786-O cells could be antagonized by miR-429 overexpression. Exogenous re-expression of CRKL abrogated miR-429 suppression on the migration and invasion of 786-O cells. Collectively, miR-429 deficiency negatively correlated with CRKL overexpression promoted the aggressiveness of cancer cells and advanced the clinical progression of ccRCC patients. miR-429-CRKL axial regulation provides new clues to the fundamental research, diagnosis and treatment of ccRCC.

A novel ETV6-miR-429-CRKL regulatory circuitry contributes to aggressiveness of hepatocellular carcinoma

BACKGROUND

Tumor metastasis is one of the main causes of the high mortality of hepatocellular carcinoma (HCC). E-Twenty Six variant gene 6 (ETV6) is a strong transcriptional repressor, associated with the development and progression of tumors. However, the exact role and underlying mechanism of ETV6 in HCC remain unclear.

METHODS

Western blotting, quantitative real-time PCR and immunohistochemistry were used to detect the expression levels of ETV6, CRKL (v-crk sarcoma virus CT10 oncogene homologue (avian)-like) and miR-429 in HCC tissues and cells; Transwell chamber and F-actin cytoskeleton staining assay to examine the effects of ETV6 and CRKL deregulation on the migration, invasion and cytoskeleton of HCC cells; Co-immunoprecipitation assay to determine the interaction between CRKL and ETV6; Chromatin immunoprecipitation assay to investigate the interaction between ETV6 and miR-429.

RESULTS

We established a novel ETV6-miR-429-CRKL regulatory circuitry contributes to HCC metastasis. ETV6 and CRKL were frequently increased, while miR-429 was downregulated in both hepatocarcinoma tissues and hepatocarcinoma cells. Moreover, ETV6 upregulation was positively correlated with CRKL upregulation, and two negative correlations were also established for ETV6 and CRKL upregulation with miR-429 downregulation in both hepatocarcinoma patients' tumorous tissues and hepatocarcinoma cells. Functional investigations revealed that overexpression and knockdown of ETV6 was remarkably effective in promoting and suppressing HCC cell migration, invasion, cytoskeleton F-actin expression and arrangement, whereas, CRKL overexpression exhibited similar effects to the overexpression of ETV6. Mechanistically, ETV6 negatively regulates miR-429 expression by directly binding to the promoter region of miR-429; miR-429 negatively regulates CRKL expression by selectively targeting CRKL-3'-UTR; ETV6 directly binds to CRKL and positively regulates its expression, which in turn CRKL positively regulates ETV6 expression.

CONCLUSIONS

Our data demonstrated that ETV6 promotes migration and invasion of HCC cells by directly binding to promoter region of miR-429 via modulating CRKL expression. The newly identified ETV6-miR-429-CRKL regulatory circuitry contributes to the aggressiveness of HCC, which provides new clues for fundamental research on diagnosis and treatment parameters for HCC.

MicroRNA-429 inhibits neuroblastoma cell proliferation, migration and invasion via the NF-κB pathway

Background

MicroRNAs (miRNAs or miRs) can participate in the development and progression of neuroblastoma. Many studies have indicated that miR-429 can participate in tumor development. However, the mechanism underlying miR-429-mediated progression of neuroblastoma remains largely unclear.

Methods

Colony formation and apoptosis assays were used to determine the effect of miR-429 on cell proliferation. Its impact on cell migration was determined using the wound-healing and Transwell assays. The target gene of miR-429 was confirmed via western blotting and luciferase reporter assays. A nude mouse xenograft model with miR-429 overexpression was used to assess the effect on tumor growth.

Results

Our findings indicate that miR-429 is downregulated in neuroblastoma cell lines. We also found that it can induce apoptosis and inhibit proliferation in cells of those lines. MiR-429 can bind to the 3′-UTR of IKKβ mRNA and overexpression of IKKβ can reverse cell proliferation, blocking the effect of miR-429. Furthermore, miR-429 overexpression inhibited neuroblastoma growth in our nude mouse xenograft model.

Conclusion

We provide important insight into miR-429 as a tumor suppressor through interaction with IKKβ, which is a catalytic subunit of the IKK complex that activates NF-κB nuclear transport. Our results demonstrate that miR-429 may be a new target for the treatment of neuroblastoma.

MicroRNA-429 inhibits bone metastasis in breast cancer by regulating CrkL and MMP-9

Bone metastasis is common in late-stage breast cancer patients and leads to skeletal-related events that affect the quality of life and decrease survival. Numerous miRNAs have been confirmed to be involved in metastatic breast cancer, such as the miR200 family. Our previous study identified microRNA-429 (miR-429) as a regulatory molecule in breast cancer bone metastasis. However, the effects of miR-429 and its regulatory axis in the metastatic breast cancer bone microenvironment have not been thoroughly investigated. We observed a positive correlation between miR-429 expression in clinical tissues and the bone metastasis-free interval and a negative correlation between miR-429 expression and the degree of bone metastasis. We cultured bone metastatic MDA-MB-231 cells and used conditioned medium (CM) to detect the effect of miR-429 on osteoblast and osteoclast cells in vitro. We constructed an orthotopic bone destruction model and a left ventricle implantation model to examine the effect of miR-429 on the metastatic bone environment in vivo. The transfection experiments showed that the expression levels of V-crk sarcoma virus CT10 oncogene homolog-like (CrkL) and MMP-9 were negatively regulated by miR-429. The in vitro coculture experiments showed that miR-429 promoted osteoblast differentiation and that CrkL promoted osteoclast differentiation. The two animal models showed that miR-429 diminished local bone destruction and distant bone metastasis but CrkL enhanced these effects. Furthermore, CrkL and MMP-9 expression decreased simultaneously in response to increased miR-429 expression. These findings further reveal the possible mechanism and effect of the miR-429/CrkL/MMP-9 regulatory axis in the bone microenvironment in breast cancer bone metastasis.

Theranostic application of miR-429 in HER2+ breast cancer

Human epidermal growth factor receptor 2 (HER2) is overexpressed/amplified in one third of breast cancers (BCs), and is associated with the poorer prognosis and the higher metastatic potential in BC. Emerging evidences highlight the role of microRNAs (miRNAs) in the regulation of several cellular processes, including BC.

Methods: Here we identified, by in silico approach, a group of three miRNAs with central biological role (high degree centrality) in HER2+ BC. We validated their dysregulation in HER2+ BC and we analysed their functional role by in vitro approaches on selected cell lines and by in vivo experiments in an animal model.

Results: We found that their expression is dysregulated in both HER2+ BC cell lines and human samples. Focusing our study on the only upregulated miRNA, miR-429, we discovered that it acts as an oncogene and its upregulation is required for HER2+ cell proliferation. It controls the metastatic potential of HER2+ BC subtype by regulating migration and invasion of the cell.

Conclusions: In HER2+ BC oncogenic miR-429 is able to regulate HIF1α pathway by directly targeting VHL mRNA, a molecule important for the degradation of HIF1α. The overexpression of miR-429, observed in HER2+ BC, causes increased proliferation and migration of the BC cells. More important, silencing miR-429 succeeds in delaying tumor growth, thus miR-429 could be proposed as a therapeutic probe in HER2+ BC tumors.

Sterol-O acyltransferase 1 is inhibited by gga-miR-181a-5p and gga-miR-429-3p through the TGFβ pathway in endodermal epithelial cells of Japanese quail

Nutrients are utilized and re-constructed by endodermal epithelial cells (EECs) of yolk sac membrane (YSM) in avian species during embryonic development. Sterol O-acyltransferase 1 (SOAT1) is the key enzyme to convert cholesterol to cholesteryl ester for delivery to growing embryos. During embryonic development, yolk absorption is concomitant with significant changes of SOAT1 mRNA concentration and enzyme activity in YSM. Presence of microRNAs (miRNAs) are observed in the embryonic liver and muscle during avian embryogenesis. However, the expression of miRNAs in YSM during embryogenesis and the involvement of miRNAs in lipid utilization are not known. Using a miRNA sequencing technique, we found several miRNA candidates and confirmed their expression patterns individually by real time PCR. MiRNA candidates were selected based on the expression pattern and their possible roles in inhibiting transforming growth factor beta receptor type 1 (TGFBR1) that would regulate the function of SOAT1. Similar to SOAT1 mRNA, the gga-miR-181a-5p expression was gradually elevated during embryonic development. However, the expression of gga-miR-429-3p in YSM was gradually decreased during embryonic development. The inhibitory effects of gga-miR-181a-5p or gga-miR-429-3p on the potential targets (SOAT1 and TGFBR1) were demonstrated by transient miRNA transfections in EECs. We also found that mutated TGFBR1 3'UTR prevented the direct pairings of gga-miR-181a-5p and gga-miR-429-3p. Treatment of TGFBR1 inhibitor, LY364947, further decreased SOAT1 transcription. Similar results were also observed by the miRNA transfection studies. The results showed the vital participations of gga-miR-181a-5p and gga-miR-429-3p in regulating TGFβ pathway, and affecting downstream SOAT1 expression and function in the YSM. This is indicative of possible regulation of avian yolk lipid utilization by changing YSM miRNA expressions.

Molecular Links between Central Obesity and Breast Cancer

Worldwide, breast cancer (BC) is the most common malignancy in women, in regard to incidence and mortality. In recent years, the negative role of obesity during BC development and progression has been made abundantly clear in several studies. However, the distribution of body fat may be more important to analyze than the overall body weight. In our review of literature, we reported some key findings regarding the role of obesity in BC development, but focused more on central adiposity. Firstly, the adipose microenvironment in obese people bears many similarities with the tumor microenvironment, in respect to associated cellular composition, chronic low-grade inflammation, and high ratio of reactive oxygen species to antioxidants. Secondly, the adipose tissue functions as an endocrine organ, which in obese people produces a high level of tumor-promoting hormones, such as leptin and estrogen, and a low level of the tumor suppressor hormone, adiponectin. As follows, in BC this leads to the activation of oncogenic signaling pathways: NFκB, JAK, STAT3, AKT. Moreover, overall obesity, but especially central obesity, promotes a systemic and local low grade chronic inflammation that further stimulates the increase of tumor-promoting oxidative stress. Lastly, there is a constant exchange of information between BC cells and adipocytes, mediated especially by extracellular vesicles, and which changes the transcription profile of both cell types to an oncogenic one with the help of regulatory non-coding RNAs.

An eight-lncRNA signature predicts survival of breast cancer patients: a comprehensive study based on weighted gene co-expression network analysis and competing endogenous RNA network

PURPOSE

To identify a lncRNA signature to predict survival of breast cancer (BRCA) patients.

METHODS

A total of 1222 BRCA case and control datasets were downloaded from the TCGA database. The weighted gene co-expression network analysis of differentially expressed mRNAs was performed to generate the modules associated with BRCA overall survival status and further construct a hub on competing endogenous RNA (ceRNA) network. LncRNA signatures for predicting survival of BRCA patients were generated using univariate survival analyses and a multivariate Cox hazard model analysis and validated and characterized for prognostic performance measured using receiver operating characteristic (ROC) curves.

RESULTS

A prognostic score model of eight lncRNAs signature was identified as Prognostic score = (0.121 × EXP_AC007731.1) + (0.108 × EXP_AL513123.1) + (0.105 × EXP_C10orf126) + (0.065 × EXP_WT1-AS) + (- 0.126 × EXP_ADAMTS9-AS1) + (- 0.130 × EXP_SRGAP3-AS2) + (0.116 × EXP_TLR8-AS1) + (0.060 × EXP_HOTAIR) with median score 1.088. Higher scores predicted higher risk. The lncRNAs signature was an independent prognostic factor associated with overall survival. The area under the ROC curves (AUC) of the signature was 0.979, 0.844, 0.99 and 0.997 by logistic regression, support vector machine, decision tree and random forest models, respectively, and the AUCs in predicting 1- to 10-year survival were between 0.656 and 0.748 in the test dataset from TCGA database.

CONCLUSIONS

The eight-lncRNA signature could serve as an independent biomarker for prediction of overall survival of BRCA. The lncRNA-miRNA-mRNA ceRNA network is a good tool to identify lncRNAs that is correlated with overall survival of BRCA.

Long non-coding RNA MALAT1 interaction with miR-429 regulates the proliferation and EMT of lung adenocarcinoma cells through RhoA

Homo sapiens metastasis associated lung adenocarcinoma transcript 1 (LncRNA MALAT1) plays an important role in many types of cancer, but its role in human lung adenocarcinoma (LAC) is still unclear. In this paper, we found that LncRNA MALAT1 had high expression in human LAC tissues (vs. paracancerous normal tissue) and human lung adenocarcinoma cells (vs. human normal lung tissue cells). The expression of lncRNA MALAT1 was significantly associated with human lung adenocarcinoma tumor size, lymph node metastasis, and TNM staging, and was negatively correlated with miR-429 expression in lung adenocarcinoma tissues. In vitro, LncRNA MALAT1 could block human LAC cells in the G1 phase to inhibit proliferation by reducing the expression of cyclin D1 protein. LncRNA MALAT1 could inhibit the invasion and migration of human LAC cells by decreasing the expression of MMP-9 and vimentin and increasing the expression of E-cadherin. We also found that Malat1 functions as a competing endogenous RNA (ceRNA) for miR-429 and directly suppressed the expression of RhoA protein. RhoA knockout and transfection of miR-429-mimic could play the same function which is to decrease the expression of cyclin D1, MMP-9, and vimentin proteins and increased E-cadherin protein expression. These results suggested that LncRNA Malat1 could promote the proliferation and EMT of human lung adenocarcinoma cells by competing with RhoA for binding to miR-429.

MicroRNA‑181 serves an oncogenic role in breast cancer via the inhibition of SPRY4

Numerous microRNAs (miRs) have been implicated in breast cancer; however, the molecular mechanism is not fully understood. The present study examined the function and regulatory mechanism of miR‑181 in breast cancer. Reverse transcription‑quantitative polymerase chain reaction and western blot analysis were used to examine the RNA and protein expression. MTT assay, wound healing assay and transwell assay were conducted to study cell proliferation, migration and invasion. Luciferase reporter gene assay was used to confirm targeting relationship. The results suggested that the miR‑181 expression levels were significantly higher in breast cancer cell lines and clinical tissue samples. The increased expression of miR‑181 was markedly associated with higher clinical stage and lymph node metastasis. The patients with high miR‑181 expression demonstrated worse prognosis compared with those with a low expression of miR‑181. Small interfering RNA‑induced miR‑181 downregulation significantly inhibited breast cancer cell proliferation, migration and invasion in vitro, and tumor growth in vivo. Protein sprouty homolog 4 (SPRY4), downregulated in breast cancer tissues and cell lines, was observed to be a novel target gene of miR‑181. Downregulation of SPRY4 was significantly associated with breast cancer progression in addition to poor prognosis. Knockdown of SPRY4 rescued the inhibitory effects of miR‑181 downregulation on the malignant phenotypes of breast cancer cells. Thus, the present study demonstrated that miR‑181 serves a promoting role in breast cancer at least in part through the inhibition of SPRY4 expression. The present results expand the understanding of the miR‑181/SPRY4 axis' function during for the malignant progression of breast cancer.

KM-express: an integrated online patient survival and gene expression analysis tool for the identification and functional characterization of prognostic markers in breast and prostate cancers

The identification and functional characterization of novel biomarkers in cancer requires survival analysis and gene expression analysis of both patient samples and cell line models. To help facilitate this process, we have developed KM-Express. KM-Express holds an extensive manually curated transcriptomic profile of 45 different datasets for prostate and breast cancer with phenotype and pathoclinical information, spanning from clinical samples to cell lines. KM-Express also contains The Cancer Genome Atlas datasets for 30 other cancer types with matching cell line expression data for 23 of them. We present KM-Express as a hypothesis generation tool for researchers to identify potential new prognostic RNA biomarkers as well as targets for further downstream functional cell-based studies. Specifically, KM-Express allows users to compare the expression level of genes in different groups of patients based on molecular, genetic, clinical and pathological status. Moreover, KM-Express aids the design of biological experiments based on the expression profile of the genes in different cell lines. Thus, KM-Express provides a one-stop analysis from bench work to clinical prospects. We have used this tool to successfully evaluate the prognostic potential of previously published biomarkers for prostate cancer and breast cancer. We believe KM-Express will accelerate the translation of biomedical research from bench to bed.

Database URL: http://ec2-52-201-246-161.compute-1.amazonaws.com/kmexpress/index.php

Circular RNAs: Crucial regulators in the human body (Review)

Circular RNAs (circRNAs) belong to a new type of endogenous non‑coding RNAs (ncRNAs) that are derived from exons and/or introns, and are widely distributed in mammals. The majority of circRNAs have a specific expression profile in cells or tissues, as well as during different stages of development. CircRNAs were originally thought to be the products of mis‑splicing. However, with the assistance of bioinformatics tools and the rapid development of high‑throughput sequencing, an increasing body of evidence has suggested that circRNAs bind micro(mi)RNAs, and have a role as miRNA sponges, thereby regulating target mRNA splicing and transcription. Human diseases are closely associated with circRNAs, especially in cancer as their expression is typically altered during the progression of cancer; this may provide a novel type of biomarker for cancer diagnosis and prognosis. CircRNAs are becoming a key area of interest within the field of cancer research. In the present review, we summarize the known molecular mechanisms and biological origin of circRNAs, as well as their functions, especially those related to human tumors.

miRNA in a multiomic context for diagnosis, treatment monitoring and personalized management of metastatic breast cancer

Metastatic breast cancer is characterized by aggressive spreading to distant organs. Despite huge multilevel research, there are still several important challenges that have to be clarified in the management of this disease. Therefore, recent investigations have implemented a modern, multiomic approach with the aim of identifying specific biomarkers for not only early detection but also to predict treatment responses and metastatic spread. Specific attention is paid to short miRNAs, which regulate gene expression at the post-transcriptional level. Aberrant miRNA expression could initiate cancer development, cell proliferation, invasion, migration, metastatic spread or drug resistance. An miRNA signature is, therefore, believed to be a promising biomarker and prediction tool that could be utilized in all phases of carcinogenesis. This article offers comprehensive information about miRNA profiles useful for diagnostic and treatment purposes that may sufficiently advance breast cancer management and improve individual outcomes in the near future.

Polymorphism rs7521584 in miR‑429 is associated with the severity of atrophic gastritis in patients with Helicobacter pylori infection

The aim of the present study was to investigate an association of genetic polymorphism (rs7521584) located in miR‑200a‑200b‑429 cluster, which has tumor suppressor and pro‑inflammatory function, with the development of gastric mucosal atrophy and metaplasia as a pre‑malignant condition. Gastric mucosa samples were obtained from the antrum of 393 patients with no malignancies. The rs7521584 genotype was determined using the polymerase chain reaction‑single‑strand conformation polymorphism analysis method. The degree of gastritis was assessed histologically in all subjects and serum levels of pepsinogen (PG) I/II were quantified in 123 out of 393 patients. Patients with an atrophy score ≥1 and metaplasia score ≥1 were classified into the atrophic gastritis group (AG group). The rs7521584 TT genotype was significantly associated with the development of atrophic gastritis [odds ratio (OR), 2.41; 95% confidence interval (CI), 1.10‑5.25; P=0.027), particularly in patients with H. pylori infection (OR, 3.31; 95% CI, 1.35‑8.12; P=0.0089). In addition, in patients younger than 60 years of age, this genotype was associated with atrophic gastritis (OR, 3.15; 95% CI 1.03‑9.61; P=0.044)]. In patients with H. pylori infection, the metaplasia score was significantly higher in the TT homozygote compared with the GG+GT genotype. In the rs7521584 TT homozygote, serum PG I/II ratio was significantly reduced with increasing age (P=0.0084). No significant trend was identified between the GG+GT genotype and age. The results of the current study indicated that the rs7521584 minor allele homozygote was associated with the development of chronic gastritis under the influence of H. pylori‑induced inflammation, particularly with the severity of metaplastic alterations.

NEAT1 contributes to breast cancer progression through modulating miR-448 and ZEB1

Breast cancer is a kind of common female cancers. Increasing evidence has exhibited that lncRNAs exert a crucial role in breast cancer. So far, the mechanism of lncRNAs in breast cancer is still not well established. In our current study, we focused on the biological role of lncRNA Nuclear Enriched Abundant Transcript 1 (NEAT1) in breast cancer. We observed that NEAT1 levels were significantly increased in human breast cancer cells including MCF-7, MDA-MB-453, MDA-MB-231, and SKBR3 cells compared to normal mammary epithelial cells MCF-10A while miR-448 was decreased. We found that downregulation of NEAT1 was able to inhibit the growth of breast cancer cells and miR-448 mimic exerted the similar function. Bioinformatics analysis and dual luciferase reporter assays confirmed the negative correlation between NEAT1 and miR-448 in vitro. In addition, ZEB1 was predicted as a novel mRNA target of miR-448. Overexpression of NEAT1 can induce breast cancer cell growth, migration, and invasion by inhibiting miR-448 and upregulating ZEB1. It was demonstrated that NEAT1 can increase ZEB1 levels while miR-448 mimic can repress ZEB1. It was speculated in our study that NEAT1 can serve as a competing endogenous lncRNA (ceRNA) to modulate ZEB1 by sponging miR-448 in breast cancer. To conclude, we uncovered that NEAT1 participated in breast cancer progression by regulating miR-448 and ZEB1. NEAT1 can be provided as a vital biomarker in breast cancer diagnosis and treatment therapy.

Identification of cancer-related miRNA-lncRNA biomarkers using a basic miRNA-lncRNA network

LncRNAs are regulatory noncoding RNAs that play crucial roles in many biological processes. The dysregulation of lncRNA is thought to be involved in many complex diseases; lncRNAs are often the targets of miRNAs in the indirect regulation of gene expression. Numerous studies have indicated that miRNA-lncRNA interactions are closely related to the occurrence and development of cancers. Thus, it is important to develop an effective method for the identification of cancer-related miRNA-lncRNA interactions. In this study, we compiled 155653 experimentally validated and predicted miRNA-lncRNA associations, which we defined as basic interactions. We next constructed an individual-specific miRNA-lncRNA network (ISMLN) for each cancer sample and a basic miRNA-lncRNA network (BMLN) for each type of cancer by examining the expression profiles of miRNAs and lncRNAs in the TCGA (The Cancer Genome Atlas) database. We then selected potential miRNA-lncRNA biomarkers based on the BLMN. Using this method, we identified cancer-related miRNA-lncRNA biomarkers and modules specific to a certain cancer. This method of profiling will contribute to the diagnosis and treatment of cancers at the level of gene regulatory networks.

Downregulation of hsa_circ_0011946 suppresses the migration and invasion of the breast cancer cell line MCF-7 by targeting RFC3

Introduction

Although some circRNAs have been found to regulate the progression of malignancies, their functions and coupled molecular mechanisms are still unclear. In our study, we sought to assess the underlying molecular mechanisms of circRNAs in breast cancer and therefore explored the differentially expressed circRNAs and co-expression networks, followed by in vitro experiments.

Materials and methods

High-throughput RNA sequencing was performed to obtain an unbiased profile of circRNA expression. CircRNA-miRNA-mRNA co-expression networks were predicted, and sequence analyses were carried out. The MTT, transwell migration and invasion assay was conducted in Michigan Cancer Foundation-7 cells that had been transfected with si-circRNA and si-negative control (si-NC).

Results

A total of 152 circRNAs were differentially expressed in breast cancer tissues, among which 85 were upregulated and 67 downregulated. Out of these, hsa_circ_0011946 was selected and the subsequent bioinformatics analysis predicted that hsa_circ_0011946 sponging miR-26a/b directly targeted replication factor C subunit 3 (RFC3) and that its knockdown could inhibit RFC3 mRNA and protein expression. Furthermore, hsa_circ_0011946 loss-of-function significantly suppressed the migration and invasion of Michigan Cancer Foundation-7 cells.

Conclusion

Together, these results indicate that hsa_circ_0011946 and RFC3 comprise a novel pathway involved in the progression of breast cancer.

miR-429 expression in bladder cancer and its correlation with tumor behavior and clinical outcome

We previously showed that microRNA-429 (miR-429) played an important role in epithelial-mesenchymal transition (EMT) of urothelial cell carcinoma of the bladder. We herein evaluated the expression of miR-429 in bladder cancer and its potential relevance to clinicopathological characteristics and patient survival. Relative expression levels of miR-429 in surgical bladder cancer tissue specimens obtained from 76 patients with bladder cancer were measured by chromogenic in situ hybridization. miR-429 expression was significantly higher in specimens from alive patients than expired patients in both of 5-year overall survival (OS) (0.59 ± 0.09 vs. 0.27 ± 0.12; p < 0.05) and 5-year recurrence-free survival (RFS) (0.63 ± 0.10 vs. 0.33 ± 0.10; p < 0.05). The univariate Cox proportional hazards analysis revealed that tumor grade, stage, and miR-429 expression were significantly associated with patient survival. In multivariate analysis, tumor stage and miR-429 expression were significantly associated with 5-year OS (hazard ratio [HR] 4.70, p < 0.001) and 5-year-RFS (HR 2.20, p < 0.05). The Kaplan-Meier analysis showed that patients with miR-429 expression had significantly better 5-year OS and 5-year RFS rates than those without miR-429 expression (84.4% vs. 61.4%, p < 0.05 and 71.9% vs. 45.5%, p < 0.05, respectively). miR-429 may be considered as an adjunctive prognostic marker in addition to tumor grade and stage in bladder cancer.

Differential Expression of MicroRNAs in Uterine Cervical Cancer and Its Implications in Carcinogenesis; An Integrative Approach

Objectives

Cervical cancer is the second most common cancer in women in developing countries, including India. Recently, microRNAs (miRNAs) are gaining importance in cancer biology because of their involvement in various cellular processes. The present study aimed to profile miRNA expression pattern in cervical cancer, identify their target genes, and understand their role in carcinogenesis.

Methods

Human papillomavirus (HPV) infection statuses in samples were assessed by heminested polymerase chain reaction followed by direct DNA sequencing. Next-generation sequencing and miRNA microarray were used for miRNA profiling in cervical cancer cell lines and tissue samples, respectively. MicroRNA signature was validated by quantitative real-time PCR, and biological significance was elucidated using various in silico analyses.

Results

Cervical cancer tissues samples were mostly infected by HPV type 16 (93%). MicroRNA profiling showed that the pattern of miRNA expression differed with respect to HPV positivity in cervical cancer cell lines. However, target and pathway analyses indicated identical involvement of these significantly deregulated miRNAs in HPV-positive cervical cancer cell lines irrespective of type of HPV infected. Microarray profiling identified a set of miRNAs that are differentially deregulated in cervical cancer tissue samples which were validated using quantitative real-time PCR. In silico analyses revealed that the signature miRNAs are mainly involved in PI3K-Akt and mTOR pathways.

Conclusions

The study identified that high-risk HPV induces similar carcinogenic mechanism irrespective of HPV type. The miRNA signature of cervical cancer and their target genes were also elucidated, thereby providing a better insight into the molecular mechanism underlying cervical cancer development.

miR-429 suppresses tumor migration and invasion by targeting CRKL in hepatocellular carcinoma via inhibiting Raf/MEK/ERK pathway and epithelial-mesenchymal transition

Tumor metastasis is one of the main causes of hepatocellular carcinoma (HCC) high mortality. CRKL (v-crk sarcoma virus CT10 oncogene homologue (avian)-like) play important roles in tumor metastasis, however, the exact role and underlying mechanism of CRKL in HCC is still unknown. In our study, we demonstrated miR-429 negatively regulated CRKL expression via selectively binding to CRKL-3'-UTR at 3728-3735 bp site by post-transcriptionally mediating its functionality. Re-expression and silencing of miR-429 was remarkably effective in suppressing and promoting HepG2 cell migration and invasion in vitro. Knockdown or overexpression of CRKL exhibited similar effects as the overexpression or silencing of miR-429, whereas, CRKL overexpression (without the 3'-UTR) abrogated miR-429-induced inhibition on HepG2 migration and invasion. Moreover, miR-429-CRKL axis affected HepG2 migration and invasion potentials by regulating the adhesion ability, cytoskeleton F-actin expression and arrangement of HepG2. Furthermore, interference of Raf/MEK/ERK pathway and EMT contributed to miR-429-CRKL axis mediated metastasis inhibition. Nevertheless, miR-429 could not inhibit HepG2 proliferation through CRKL/c-Jun pathway. Taken together, our data demonstrated that miR-429 might function as an antimetastatic miRNA to regulate HCC metastasis by directly targeting CRKL via modulating Raf/MEK/ERK-EMT pathway. The newly identified miR-429-CRKL axis represents a novel potential therapeutic target for HCC treatment.

MiR-378 and MiR-1827 Regulate Tumor Invasion, Migration and Angiogenesis in Human Lung Adenocarcinoma by Targeting RBX1 and CRKL, Respectively

MicroRNAs (miRNAs) have been extensively studied over the decades and have been proposed as potential molecular targets for cancer treatment. Studies have shown that miR-378 participates in numerous biological processes in various cancers; whereas miR-1827 has only been reported in pediatric glioma. The mechanism of how miRNAs modulate lung cancer metastasis remains unclear. Our previous study demonstrated that miR-378 is up-regulated while miR-1827 is down-regulated in high invasive lung cancer sub-cell lines, and their biological functions have been described. Here, we report that miR-378 and miR-1827 modulate lung cancer cell invasion and migration via epithelial-mesenchymal transition (EMT). We also demonstrated that cells treated with miR-378 inhibitors or miR-1827 mimics had reduced number of metastases and ectopic vessels in the zebrafish embryo model. We then showed that miR-378 promoted invasion and miR-1827 suppressed migration by targeting RBX1 and CRKL, respectively. Restored protein expression in miRNA-overexpressed/ miRNA-suppressed cells attenuated the inhibitory/ inducing effect of the miRNA on lung cancer cells. Collectively, our findings highlight that miR-378 and miR-1827 could serve as novel therapeutic targets in lung cancer.

miRNAs in bone metastasis

Bone metastasis is one of the most common forms of metastasis from a number of different primary carcinomas. MicroRNAs (miRNAs) are short, endogenous RNAs that negatively regulate gene expression to control essential pathways, including those involved in bone organogenesis and homeostasis. As these pathways are often hijacked during bone metastasis, it is not surprising that miRNAs can also influence bone metastasis formation. Areas covered: In this review, we first summarize the major signalling pathways involved in normal bone development and bone metastasis. We will then discuss the overall roles of miRNAs in cancer metastasis and highlight the recent findings on the effects of miRNAs in bone metastasis. To this aim, we have performed a literature search in PubMed by using the search words 'miRNAs' and 'bone metastasis', selecting relevant scientific articles published between 2010 and 2016. Seminal publications before 2010 on the metastatic role of miRNAs have also been considered. Expert commentary: With the lack of current diagnostic biomarkers and effective targeted therapies for bone metastasis, the significant role of miRNAs in the regulation of bone homeostasis and bone metastasis may support the future use of miRNAs as diagnostic biomarkers and therapeutic targets.

MiR-429 suppresses glioblastoma multiforme by targeting SOX2

Accumulating evidence has shown that miR-429 plays an important role in the development and progression of tumour. However, the role of miR-429 in glioblastoma multiforme (GBM) remains largely unknown. The present study is designed to investigate the function of miR-429 in GBM and to explore the molecular mechanism underlying its function. The expression level of miR-429 was detected in GBM tissues and cell lines by quantitative real-time polymerase chain reaction. The effect of overexpression of miR-429 on in vitro cell proliferation, apoptosis and invasion was examined. Western blot analysis was used to detect the influence of miR-429 on the expression of target gene, and Pearson analysis was used to calculate the correlation between the expression of targets gene and the miR-429 in GBM tissues. Our study shows that miR-429 is downregulated in GBM tissues compared with noncancerous tissues (P < .01). In addition, the expression of miR-429 in GBM cell lines is also significantly lower (P < .01). Enforced expression of miR-429 inhibits GBM cells proliferation, induces apoptosis and suppresses invasion and leads to the downregulation of the SOX2 protein. Moreover, the expression level of miR-429 in GBM tissues shows inverse relationship with the expression level of SOX2 protein. Our findings suggest that miR-429 represents a potential tumour-suppressive miRNA and plays an important role in GBM progression by directly targeting SOX2.

Regulation of microRNAs function by circular RNAs in human cancer

Circular RNAs (circRNAs) are a newly validated class of endogenous non-coding RNA, generated from the ligation of exons, introns, or both, which arise via a diverse number of cellular mechanisms. Due to rapid advances in the development of combined high-throughput sequencing and bioinformatics analyzing tools, many circRNAs have recently been discovered, revealing an expansive number of ubiquitously expressed mammalian circRNAs. Interestingly, it has recently been confirmed that circRNAs bind to microRNAs (miRs), as miR “sponges”, acting to suppress miR function. As miRs are known to alter the development and progression of cancer, circRNAs may offer a novel diagnostic and prognostic biomarker for cancer. Indeed, recent evidence has shown that circRNAs are associated with many human cancers. Herein, we review the molecular characteristics and biogenesis of circRNAs, with a focus on newly identified circRNAs that may play an important role in human cancer, through their regulation of miR expression.

Recent progress on the effects of microRNAs and natural products on tumor epithelial-mesenchymal transition

Epithelial–mesenchymal transition (EMT) is a biological process of phenotypic transition of epithelial cells that can promote physiological development as well as tissue healing and repair. In recent years, cancer researchers have noted that EMT is closely related to the occurrence and development of tumors. When tumor cells undergo EMT, they can develop enhanced migration and local tissue invasion abilities, which can lead to metastatic growth. Nevertheless, two researches in NATURE deny its necessity in specific tumors and that is discussed in this review. The degree of EMT and the detection of EMT-associated marker molecules can also be used to judge the risk of metastasis and to evaluate patients’ prognosis. MicroRNAs (miRNAs) are noncoding small RNAs, which can inhibit gene expression and protein translation through specific binding with the 3′ untranslated region of mRNA. In this review, we summarize the miRNAs that are reported to influence EMT through transcription factors such as ZEB, SNAIL, and TWIST, as well as some natural products that regulate EMT in tumors. Moreover, mutual inhibition occurs between some transcription factors and miRNAs, and these effects appear to occur in a complex regulatory network. Thus, understanding the role of miRNAs in EMT and tumor growth may lead to new treatments for malignancies. Natural products can also be combined with conventional chemotherapy to enhance curative effects.

The microRNAs miR-200b-3p and miR-429-5p target the LIMK1/CFL1 pathway to inhibit growth and motility of breast cancer cells

Triple-negative breast cancer (TNBC) has the worst prognosis of all subtypes of breast cancer (BC), with limited options for conventional therapy and no targeted therapies. MicroRNAs (miRNAs) are small noncoding RNAs that negatively regulate gene expression. In this study, we aimed to determine whether two members of the miR-200 family, miR-200b-3p and miR-429-5p, are involved in BC cell proliferation and motility and to elucidate their target genes and pathways. We performed a meta-analysis that reveals down-regulated expression of miR-200b-3p and miR-429-5p in BC tissues and cell lines, consistent with a lower expression of miR-200b-3p and miR-429-5p in MDA-MB-231 and HCC1937 cells than in MCF-7 and MCF-10 cells. Overexpression of miR-200b-3p and miR-429-5p significantly inhibited the proliferation, migration, and invasion of TNBC cells; suppressed the expression of markers for proliferation and metastasis in TNBC cells. We next demonstrated that LIM domain kinase 1 (LIMK1) is a direct target gene of miR-200b-3p and miR-429-5p. Inhibition of LIMK1 reduced the expression and phosphorylation of cofilin 1 (CFL1), which polymerizes and depolymerizes F-actin and G-actin to reorganize cellular actin cytoskeleton. In addition, transfection with mimics for miR-200b-3p and miR-429-5p arrested G2/M and G0/G1 cell cycles respectively, suppressed the expression of the cell cycle–related complexes, cyclin D1/CDK4/CDK6 and cyclin E1/CDK2, in TNBC cells. In conclusion, miR-200b-3p and miR-429-5p suppress proliferation, migration, and invasion in TNBC cells, via the LIMK1/CFL1 pathway. These results provide insight into how specific miRNAs regulate TNBC progression and suggest that the LIMK1/CFL1 pathway is a therapeutic target for treating TNBC.

MicroRNA-22 inhibits cell growth and metastasis in breast cancer via targeting of SIRT1

MicroRNAs (miRs), which are a class of small non-coding RNAs, are key regulators of gene expression via induction of translational repression or mRNA degradation. However, the molecular mechanism of miR-22 underlying the malignant progression of breast cancer, remains to be elucidated. The present study aimed to explore the regulatory mechanism of miR-22 in breast cancer cell growth and metastasis. Reverse transcription-quantitative polymerase chain reaction data revealed that miR-22 was significantly downregulated in breast cancer tissues, compared with adjacent non-tumor tissues. Furthermore, the miR-22 levels were further decreased in stage III–IV, compared with stage I–II breast cancer. In addition, low miR-22 levels were significantly associated with the poor differentiation, metastasis and advanced clinical stages of breast cancer. Sirtuin1 (SIRT1) was demonstrated to act as a direct target gene of miR-22 and its protein expression negatively regulated by miR-22 in the MCF-7 breast cancer cell line. Furthermore, SIRT1 expression levels were significantly upregulated in breast cancer tissues, compared with adjacent non-tumor tissues. SIRT1 levels were observed to be increased in stage III–IV when compared with stage I–II breast cancer. miR-22 overexpression decreased the proliferation, migration and invasion of MCF-7 cells, whereas overexpression of SIRT1 eliminated the suppressive effects of the miR-22 overexpression on the malignant phenotype of MCF-7 cells. The results of the present study therefore suggested that miR-22 demonstrated suppressive effects on breast cancer growth and metastasis via targeting SIRT1, and thus the miR-22/SIRT1 axis may be used as a novel and potential therapeutic target for breast cancer in the future.

MiR-429 suppresses the progression and metastasis of osteosarcoma by targeting ZEB1

MiR-429 functions as a tumor suppressor and has been observed in multiple types of cancer, but the effects and mechanisms of miR-429 in osteosarcoma are poorly understood. This study is performed to evaluate the functions of miR-429 in the progression of osteosarcoma. Firstly, the miR-429 expression in osteosarcoma tissues and osteosarcoma cells was detected using real time PCR, and the relationship between miR-429 expression and overall survival of osteosarcoma was analyzed. Secondly, the effects of miR-429 on the migration, invasion, proliferation and apoptosis of osteosarcoma cells were evaluated using transwell assay, wound-healing assay, CCK-8 assay and flow cytometry, respectively. Proteins related to epithelial-mesenchymal transition (EMT), E-cadherin, Vimentin, N-cadherin and Snail, were also detected using Western blot. Finally, the target gene of miR-429 in osteosarcoma was predicted and verified using dual luciferase assay and the expression correlation between them was analyzed using Pearson's correlation. MiR-429 was down-regulated in osteosarcoma tissues and osteosarcoma cells; the expression level of miR-429 was associated with the prognosis of osteosarcoma. High level of miR-429 in osteosarcoma cells significantly suppressed the migration, invasion and proliferation of cells but induced cells apoptosis. Furthermore, high level of miR-429 in osteosarcoma cells obviously increased the expression of E-cadherin protein but decreased the expression of Vimentin, N-Cadherin and Snail proteins. EMT inducer ZEB1 was the target gene of miR-429 and the expression of ZEB1 was negatively related to the miR-429 expression in osteosarcoma. In conclusion, miR-429 may functions as a tumor suppressor and be down-regulated in osteosarcoma. MiR-429 may suppress the progression and metastasis of osteosarcoma by down-regulating the ZEB1 expression.

MicroRNA-429 inhibits gastric cancer migration and invasion through the downregulation of specificity protein 1

microRNAs (miRs) have been reported to have an important role in tumorigenesis and tumor progression. Although miR-429 has been shown to be downregulated in gastric cancer (GC), the function of miR-429 in the metastasis of GC has yet to be investigated. In the present study, GC cells were transfected with miR-429, and reverse transcription-quantitative polymerase chain reaction, cell migration assays, cell invasion assays, western blot analysis and luciferase assays were conducted to investigate the role of miR-429 in GC cells. It was demonstrated that miR-429 expression was markedly increased following transfection of the cells with miR-429. Furthermore, miR-429 was shown to inhibit the migration and invasion of GC cell lines. In addition, this study provided evidence that miR-429 directly targets specificity protein 1 in GC cells. The results of the present study may enhance current knowledge regarding the molecular basis of cancer metastasis and provide a potential therapeutic strategy for GC.

Upregulated microRNA-429 inhibits the migration of HCC cells by targeting TRAF6 through the NF-κB pathway

Increasing evidence indicates that miR-429 is involved in tumor suppression in various human cancers. however, its role in hepatocellular carcinoma (HCC) remains unclear. In the present study, we found that miR-429 was significantly downregulated in HCC tissue samples and cell lines. Upregulation of miR-429 markedly suppressed proliferation and migration of HCC cells. Moreover, we identified TRAF6 as a direct target of miR-429. Downregulation of TRAF6 partially attenuated the oncogenic effect of anti‑miR-429 on HCC cells. Ectopic expression of miR-429 in HCC cells inhibited TCF-4 activity as well as nuclear accumulation of P65 and expression of the NF-κB targets c-Myc and phosphorylation of TAK1. In a nude xenograft model, miR-429 upregulation significantly decreased HCC growth. In conclusion, by targeting TRAF6, miR-429 is downregulated in HCC and inhibits HCC cell proliferation and motility. Our data suggest that miR-429 may serve as a potential anticancer target for the treatment of HCC.

miR-429 mediates tumor growth and metastasis in colorectal cancer

Colorectal cancer (CRC), presenting the third most common malignancy worldwide. In recent years, the aberrantly upregulation or downregulation of miRNAs in CRC have been evidenced in a number of studies. In this study, our results showed that the expression of miR-429 was significantly higher in CRC tissue compared with adjacent non-tumor tissue. In addition, our findings showed that miR-429 level was significantly associated with clinicoplathological features and prognosis of patients with CRC. Moreover, our findings showed that miR-429 exerted oncogenic effect by directly targeting HOXA5, a transcription factor of HOX families that is involved in the development and progression of CRC.