MiR-539 inhibits thyroid cancer cell migration and invasion by directly targeting CARMA1

MiR-138-5p Inhibits Thyroid Cancer Cell Growth and Stemness by Targeting TRPC5/Wnt/β-Catenin Pathway

MicroRNAs play a key role in the pathogenesis of many types of cancer, including thyroid cancer (TC). MiR-138-5p has been confirmed to be abnormally expressed in TC tissues. However, the role of miR-138-5p in TC progression and its potential molecular mechanism need to be further explored. In this study, quantitative real-time PCR was used to examine miR-138-5p and TRPC5 expression, and western blot analysis was performed to examine the protein levels of TRPC5, stemness-related markers, and Wnt pathway-related markers. Dual-luciferase reporter assay was used to assess the interaction between miR-138-5p and TRPC5. Cell proliferation, stemness, and apoptosis were examined using colony formation assay, sphere formation assay, and flow cytometry. Our data showed that miR-138-5p could target TRPC5 and its expression was negatively correlated with TRPC5 expression in TC tumor tissues. MiR-138-5p decreased proliferation, stemness, and promoted gemcitabine-induced apoptosis in TC cells, and this effect could be reversed by TRPC5 overexpression. Moreover, TRPC5 overexpression abolished the inhibitory effect of miR-138-5p on the activity of Wnt/β-catenin pathway. In conclusion, our data showed that miR-138-5p suppressed TC cell growth and stemness via the regulation of TRPC5/Wnt/β-catenin pathway, which provided some guidance for studying the potential function of miR-138-5p in TC progression.

Selective inhibition of DNA ligase IV provides additional efficacy to the treatment of anaplastic thyroid cancer

Background

Although the incidence of anaplastic thyroid carcinoma (ATC) is low (2.5% of thyroid cancer cases), this cancer has a very poor prognosis (survival rates < 5 months) and accounts for 14-39% of deaths. Conventional therapies based on surgery in combination with radiotherapy or chemotherapy showed limited effectiveness primarily due to the robust and protective DNA damage response in thyroid cancer cells.

Methods

We used single-cell transcriptomic data from patients with different subtypes of thyroid cancer to study expression of genes involved in homologous recombination (HR) and non-homologous end joining (NHEJ) pathways. Then, we investigated the mechanisms of DNA damage and repair in anaplastic (C643 and Hth74) and papillary (TPC-1) thyroid cancer cell lines. The effect of caffeine (inhibitor of ATM and ATR) and UCN-01 (CHK1 inhibitor) was evaluated in cell cycle progression of thyroid cancer cells after γ-radiation or doxorubicin treatment. The DNA damage response was monitored after staining of phosphorylated γ-H2AX and 53BP1. Reporter plasmids were used to determine the efficacy of double-strand DNA breaks (DSBs) repair by HR and NHEJ in thyroid cancer cells. We evaluated the combination of selective inhibition of the DNA ligase IV by SCR7 and doxorubicin on cellular apoptosis and tumor growth in xenograft murine models of anaplastic thyroid cancer.

Results

Single-cell RNA-Seq showed that NHEJ- and HR-related genes are expressed in ATC and PTC patients. We showed that ATC cells undergo mitosis in the presence of unrepaired DNA damage caused by γ-radiation and doxorubicin treatment. To proliferate and survive, these cells efficiently repair DNA lesions using homologous recombination (HR) and non-homologous end joining (NHEJ). The combination of SCR7 with doxorubicin, significantly increased apoptosis and impaired ATC tumor growth in a xenograft mouse model compared to doxorubicin monotherapy.

Conclusion

This study shows the therapeutic value of the combination of a DNA ligase IV inhibitor and DNA-damaging agents (doxorubicin and/or γ-radiation) for the treatment of anaplastic thyroid cancer.

LncRNA ATP1A1-AS1 inhibits cell proliferation and promotes cell apoptosis in thyroid carcinoma by regulating the miR-620/IRF2BP2 axis

BACKGROUND

Thyroid carcinoma (THCA) is a common malignancy of the endocrine system. Further understanding of the molecular mechanism underlying THCA is crucial to develop effective diagnostic therapy and improve its treatments. In this study, we intended to provide novel direction for THCA targeted therapy from the aspect of lncRNA-miRNA-mRNA interaction. We aimed to investigate the function and molecular mechanism of lncRNA ATP1A1-AS1 in THCA.

METHODS

Gene expression was assessed by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Cell growth was detected by CCK-8 and EdU assays. Flow cytometry was applied for analyzing cell apoptosis. The binding of ATP1A1-AS1 or IRF2BP2 to miR-620 was validated by RNA pulldown and luciferase reporter assays. The protein levels were examined by western blotting.

RESULTS

ATP1A1-AS1 was decreased in THCA cells and tissues. ATP1A1-AS1 overexpression attenuated cell growth and promoted apoptosis. MiR-620, which was upregulated in THCA, was identified as a direct target of ATP1A1-AS1. Furthermore, IRF2BP2 was discovered to be a target of miR-620, which displayed low expression in THCA cells and tissues. Importantly, IRF2BP2 knockdown reversed the influence of ATP1A1-AS1 overexpression on THCA cell proliferation and apoptosis.

CONCLUSIONS

LncRNA ATP1A1-AS1 inhibited cell growth and promotes apoptosis in THCA via the miR-620/IRF2BP2 axis.

MicroRNAs as the critical regulators of cell migration and invasion in thyroid cancer

Thyroid cancer (TC) is one of the most frequent endocrine malignancies that is more common among females. Tumor recurrence is one of the most important clinical manifestations in differentiated TC which is associated with different factors including age, tumor size, and histological features. Various molecular processes such as genetic or epigenetic modifications and non-coding RNAs are also involved in TC progression and metastasis. The epithelial-to-mesenchymal transition (EMT) is an important biological process during tumor invasion and migration that affects the initiation and transformation of early-stage tumors into invasive malignancies. A combination of transcription factors, growth factors, signaling pathways, and epigenetic regulations affect the thyroid cell migration and EMT process. MicroRNAs (miRNAs) are important molecular factors involved in tumor metastasis by regulation of EMT-activating signaling pathways. Various miRNAs are involved in the signaling pathways associated with TC metastasis which can be used as diagnostic and therapeutic biomarkers. Since, the miRNAs are sensitive, specific, and non-invasive, they can be suggested as efficient and optimal biomarkers of tumor invasion and metastasis. In the present review, we have summarized all of the miRNAs which have been significantly involved in thyroid tumor cells migration and invasion. We also categorized all of the reported miRNAs based on their cellular processes to clarify the molecular role of miRNAs during thyroid tumor cell migration and invasion. This review paves the way of introducing a non-invasive diagnostic and prognostic panel of miRNAs in aggressive and metastatic TC patients.

MiR-200c promotes papillary thyroid cancer cell proliferation, migration, and invasion by downregulating PTEN

MiR-200c has been reported in several types of human cancer. Nevertheless, the expression profile and biological functions of miR-200c remain uncovered papillary thyroid cancer (PTC). The expression level of miR-200c was evaluated in PTC tissues using RT-qPCR. Survival analysis was performed in a cohort of 88 PTC patients. The effects of miR-200c on cell proliferation, migration, and invasion capacities were analyzed using CCK-8 and transwell assays. Target genes of miR-200c were assessed using luciferase reporter assay, RT-qPCR, Western blot and rescue experiments. MiR-200c was found to be upregulated in human PTC tissues and closely associated with pN stage and distant metastasis. High expression of miR-200c was associated with poor clinical prognosis in PTC patients. Whilst overexpression of miR-200c was demonstrated to promote the proliferation, migration, and invasion of PTC cells; knockdown of miR-200c showed an opposite inhibitory effect. Bioinformatics analysis and luciferase reporter assays confirmed that PTEN is a downstream target of miR-200c. Functional assays demonstrated that PTC cell proliferation, migration, and invasion were promoted by miR-200c via negative regulation of PTEN. Finally, overexpression of PTEN was shown to partially reverse the tumor promoting effect of miR-200c. In conclusion, this study indicates that miR-200c is a crucial prognostic biomarker of PTC, and that targeting of miR-200c/ PTEN axis may be of therapeutic significance in PTC patients.

Circular RNA Circ_0067934 Attenuates Ferroptosis of Thyroid Cancer Cells by miR-545-3p/SLC7A11 Signaling

Ferroptosis is an emerging programmed cell death distinguished from apoptosis and autophagy and plays essential roles in tumorigenesis. Thyroid cancer is a prevalent endocrine tumor, but the molecular mechanism of ferroptosis during thyroid cancer development remains unclear. Here, we identified the critical function of circular RNA circ_0067934 in repressing ferroptosis of thyroid cancer cells. Our data showed that the ferroptosis activator erastin decreased thyroid cancer cell viabilities, while the circ_0067934 shRNA further attenuated erastin-inhibited cell viabilities. The silencing of circ_0067934 enhanced the levels of ferroptosis-related markers, including Fe2+, iron, and ROS in the cells. The knockdown of circ_0067934 induced thyroid cancer cell apoptosis and repressed thyroid cancer cell proliferation in vitro and in vivo. Circ_0067934 upregulated the expression of the ferroptosis-negative regulator SLC7A11 by sponging and inhibiting miR-545-3p in thyroid cancer cells. The overexpression of SLC7A11 or the inhibitor of miR-545-3p reversed circ_0067934 silencing-regulated thyroid cancer cell proliferation. Therefore, we concluded that Circ_0067934 attenuated ferroptosis of thyroid cancer cells by miR-545-3p/SLC7A11 signaling. Circ_0067934 may serve as a potential therapeutic target by regulating ferroptosis for the treatment of thyroid cancer.

The effect of miR-539 regulating TRIAP1 on the apoptosis, proliferation, migration and invasion of osteosarcoma cells

Objective

The purpose of this study is to explore the effect of miRNA-539 on osteosarcoma (OS) and the underlying mechanism, so as to find a new method for early diagnosis and treatment of osteosarcoma.

Method

miRNA-539 mimics was transfected into osteosarcoma cells 143b and MG-63 and upregulated the expression of miR-539. QT-PCR was used to detect transfection efficacy. CCK-8 method was used to detect proliferation of 143b and MG-63 osteosarcoma cells and flow cytometry was used to detect the apoptosis of osteosarcoma cells 143b and MG-63. Wound-healing test and Transwell test were used to detect the migration and invasion ability of osteosarcoma cells. TRIAP1 was found to be the potential target gene of miRNA-539 by online bioinformatics software and the expression level of TRIAP1 in osteosarcoma cells overexpressing miRNA-539 was detected by qT-PCR. Western blot was used to detect the level of expression of TRIAP1 and its downstream genes (p53, p21, apaf1 and caspase9) in osteosarcoma cells 143b and MG63 transfected with miR-539 mimics or miR-539 mimics-NC. A model of osteosarcoma subcutaneously transplanted in nude mice was constructed to observe the effect of miRNA-539 on the growth rate of osteosarcoma in vivo.

Results

After transfection of miRNA-539 mimics in osteosarcoma cells 143b and MG63, the proliferation level, migration ability, and invasion ability of the osteosarcoma cells were significantly lower than that in the control group, and the apoptosis level was significantly higher than that in the control group (P < 0.01). The dual luciferase reporter confirmed that TRIAP1 was the target of miR-539, and the expression level of TRIAP1 in 143b and MG63 transfected with miRNA-539 mimics was proved to be significantly lower than that in the control group (P < 0.01).The western blot showed the expression of genes targeted by TRIAP1 was upregulated when the expression of TRIAP1 was downregulated. In vivo, the osteosarcoma growth rate in the miRNA-539 mimics group was significantly slower than that in the control group (P < 0.01).

Conclusions

MiRNA-539 may inhibit the cell proliferation, migration and invasion of osteosarcoma cells and promote the apoptosis of osteosarcoma cells by targeting on TRIAP1.

Microbial regulation of a lincRNA-miRNA-mRNA network in the mouse hippocampus

Aim: To comprehensively understand microbiota-regulated lincRNA-miRNA-mRNA networks in psychiatric disorders. Materials & methods: Integrated analyses of lincRNAs, mRNAs and miRNAs, obtained by microarray analysis of hippocampus from specific pathogen-free, germ-free and colonized germ-free mice, were performed. Results: Expression of 139 mRNAs, seven miRNAs and one lincRNA was restored following colonization. The restored transcripts were mainly involved in CREB and Ras/MAPK signaling pathways. RNA transcription and post-transcriptional regulation were the primary perturbed functions. Finally, 12 lincRNAs, six miRNAs and 47 mRNAs were included in a lincRNA-miRNA-mRNA network, and lincRNA0926-miR-190a-5p-Celf4 interactions may play a pivotal role in this regulatory network. Conclusion: This study provides clues for understanding the molecular basis of gut microbiota-brain interactions in depressive- and anxiety-like behaviors.

MiR-539 inhibits the malignant behavior of breast cancer cells by targeting SP1

The aberrant expression of microRNAs (miRNAs) is involved in the initiation and progression of human cancers. In our study, we found that miR-539 was down-regulated in breast cancer tissues and cell lines. Decreased expression of miR-539 was significantly associated with lymph node metastasis in patients with breast cancer. Overexpression of miR-539 inhibited the proliferation and promoted apoptosis of breast cancer cells. Moreover, highly expressed miR-539 significantly suppressed the epithelial-mesenchymal transition (EMT) and sensitized cells to cisplatin treatment. Mechanistically, miR-539 was found to target the specificity protein 1 (SP1) and down-regulated the expression of SP1 in breast cancer cells. Knockdown of miR-539 consistently increased the expression of SP1. The expression of miR-539 in breast cancer tissues was negatively correlated with the expression of SP1. Restoration of SP1 significantly attenuated the inhibitory effect of miR-539 on the proliferation of breast cancer cells. Taken together, our results indicate that miR-539 has a tumor suppressive role in breast cancer via targeting SP1, suggesting miR-539 as a promising target for the diagnosis of breast cancer.

Long noncoding RNA LINC00339 promotes the oncogenicity of gastric cancer by regulating SRY-box 9 expression via sponging of microRNA-539

Differential expression of LINC00339 is involved in the malignancy of multiple human cancer types. Nonetheless, the expression profile, functions, and potential mechanisms of action of LINC00339 in gastric cancer are yet to be fully elucidated. This study aimed at measuring LINC00339 expression in gastric cancer and examining the prognostic significance of LINC00339 in patients with gastric cancer. The detailed functions of LINC00339 with regard to the aggressive characteristics of gastric cancer cells and the underlying molecular mechanisms were investigated. Here, we found that LINC00339 expression was aberrantly high in gastric cancer and significantly associated with lymph node metastasis, invasive depth, and TNM stage. Patients with gastric cancer in a LINC00339 high-expression group showed shorter overall survival than patients in a LINC00339 low-expression group. A knockdown of LINC00339 suppressed gastric cancer cell proliferation, migration, and invasion and induced apoptosis in vitro and slowed tumor growth in vivo. In terms of the mechanism, LINC00339 was found to act as a molecular sponge on microRNA-539 (miR-539). SRY-box 9 (SOX9) was confirmed as a direct target gene of miR-539 in gastric cancer cells. An miR-539 knockdown attenuated the effects of the LINC00339 knockdown on the malignant characteristics of gastric cancer cells. Overall, LINC00339 plays a critical role in the malignancy of gastric cancer by regulating SOX9 via sponging of miR‑539. Our findings highlight the importance of the LINC00339-miR-539-SOX9 pathway in gastric cancer pathogenesis and may point to novel targets for the diagnosis, prognosis, and/or treatment of gastric cancer.

A comprehensive analysis for associations between multiple microRNAs and prognosis of osteosarcoma patients

Background

Osteosarcoma (OS) is the most common malignant primary bone tumor occurring in children and young adults, which occupies the second important cause of tumor-associated deaths among children and young adults. Recent studies have demonstrated that many microRNAs (miRNAs) have abnormal expression in OS, and can function as prognostic factors of OS patients. However, no previous studies have comprehensively analyzed the relationship between multiple miRNAs and prognosis of OS patients.

Methods

A total of 63 OS patients were retrospectively enrolled. The clinical characteristics were collected, and the expression levels of miRNA-21, miRNA-30c, miRNA-34a, miRNA-101, miRNA-133a, miRNA-214, miRNA-218, miRNA-433 and miRNA-539 in tumor tissues were measured through quantitative real-time polymerasechain reaction. Kaplan–Meier analysis was used to perform univariate survival analysis, and Cox regression model was used to perform multivariate survival analysis which included the variables with P < 0.1 in univariate survival analysis.

Results

The cumulative survival for 1, 2 and 5 years was 90.48%, 68.25% and 38.10%, respectively, and mean survival time was (45.39 ± 3.60) months (95% CI [38.34–52.45]). Kaplan–Meier analysis demonstrated that TNM stage, metastasis or recurrence, miRNA-21, miRNA-214, miRNA-34a, miRNA-133a and miRNA-539 were correlated with cum survival, but gender, age, tumor diameter, differentiation, miRNA-30c, miRNA-433, miRNA-101 and miRNA-218 were not. Multivariate survival analysis demonstrated that miRNA-21 (hazard ratio (HR): 3.457, 95% CI [2.165–11.518]), miRNA (HR: 3.138, 95% CI [2.014–10.259]), miRNA-34a (HR: 0.452, 95% CI [0.202–0.915]), miRNA-133a (HR: 0.307, 95% CI [0.113–0.874]) and miRNA-539 (HR: 0.358, 95% CI [0.155–0.896]) were independent prognostic markers of OS patients after adjusting for TNM stage (HR: 2.893, 95% CI [1.496–8.125]), metastasis or recurrence (HR: 3.628, 95% CI [2.217–12.316]) and miRNA-30c (HR: 0.689, 95% CI [0.445–1.828]).

Conclusions

High expression of miRNA-21 and miRNA-214 and low expression of miRNA-34a, miRNA-133a and miRNA-539 were associated with poor prognosis of OS patients after adjusting for TNM stage, metastasis or recurrence and miRNA-30c.

LncRNA LUCAT1 contributes to cell proliferation and migration in human pancreatic ductal adenocarcinoma via sponging miR-539

Pancreatic ductal adenocarcinoma is one of the most aggressive and dreadful malignancies worldwide. Long noncoding RNAs (lncRNAs) have emerged as vital regulators in the development of human malignancies and other disorders. This study aimed to characterize the role of lncRNA lung cancer-associated transcript 1 (lncRNA LUCAT1), a novel cancer-related lncRNA, in human PDAC. Here we initially analyzed the expression patterns of lncRNA LUCAT1 and evaluated its clinical significance. The qRT-PCR analysis and in situ hybridization staining showed that lncRNA LUCAT1 expression was significantly increased in tumorous tissues compared with adjacent normal tissues. Additionally, we found that increased lncRNA LUCAT1 expression was linked to larger tumor size and lymphatic invasion. Consistently, lncRNA LUCAT1 was remarkably up-regulated in PDAC cell lines. To better understand the biological role of lncRNA LUCAT1, we evaluated the effects of lncRNA LUCAT1 knockdown on PDAC cell proliferation, cell cycle progression, migration, and invasion using MTT assays, flow cytometry, Transwell migration, and invasion assays, respectively. Functional studies demonstrated that lncRNA LUCAT1 knockdown dramatically suppressed PDAC cell proliferation, induced cell cycle arrest and inhibited cell migration and invasion. Tumor xenograft in vivo assays displayed that lncRNA LUCAT1 inhibited tumorigenecity of PDAC cells. Mechanistic studies uncovered that lncRNA LUCAT1 acted as a molecular sponge of miR-539 and that miR-539 mediated the effects of lncRNA LUCAT1 on PDAC cell proliferation, cell cycle progression, and motility. Collectively, our findings may offer some novel insights into understanding lncRNA LUCAT1 in PDAC.

Nuclear Factor κB Signaling and Its Related Non-coding RNAs in Cancer Therapy

Nuclear factor κB (NF-κB) acts as a nuclear factor that is composed of five main subunits. It is a pluripotent and crucial dimer transcription factor that has a close relationship with many serious illnesses, especially its influences on cell proliferation, inflammation, and cancer initiation and progression. NF-κB acts as part of the signaling pathway and determines its effect on the expression of several other genes, such as epidermal growth factor receptor (EGFR), p53, signal transducer and activator of transcription 3 (STAT3), and non-coding RNA (ncRNA). Continuous activation of the NF-κB signaling pathway has been seen in many cancer types. While the NF-κB signaling pathway is tightly regulated in physiological settings, quite frequently it is constitutively activated in cancer, and the molecular biology mechanism underlying the deregulated activation of NF-κB signaling remains unclear. In this review, we discuss the regulatory role and possible clinical significance of ncRNA (microRNA [miRNA] and long non-coding RNA [lncRNA]) in NF-κB signaling in cancer, including in the conversion of inflammation to carcinogenesis. Non-coding RNA plays an essential and complex role in the NF-κB signaling pathway. NF-κB activation can also induce the ncRNA status. Targeting NF-κB signaling by ncRNA is becoming a promising strategy of drug development and cancer treatment.

MicroRNA-539 functions as a tumour suppressor in prostate cancer via the TGF-β/Smad4 signalling pathway by down-regulating DLX1

Prostate cancer (PCa) is the second leading cause of cancer‐related death in males, primarily due to its metastatic potential. The present study aims to identify the expression of microRNA‐539 (miR‐539) in PCa and further investigate its functional relevance in PCa progression both in vitro and in vivo. Initially, microarray analysis was conducted to obtain the differentially expressed gene candidates and the regulatory miRNAs, after which the possible interaction between the two was determined. Next, ectopic expression and knock‐down of the levels of miR‐539 were performed in PCa cells to identify the functional role of miR‐539 in PCa pathogenesis, followed by the measurement of E‐cadherin, vimentin, Smad4, c‐Myc, Snail1 and SLUG expression, as well as proliferation, migration and invasion of PCa cells. Finally, tumour growth was evaluated in nude mice through in vivo experiments. The results found that miR‐539 was down‐regulated and DLX1 was up‐regulated in PCa tissues and cells. miR‐539 was also found to target and negatively regulate DLX1 expression, which resulted in the inhibition of the TGF‐β/Smad4 signalling pathway. Moreover, the up‐regulation of miR‐539 or DLX1 gene silencing led to the inhibition of PCa cell proliferation, migration, invasion, EMT and tumour growth, accompanied by increased E‐cadherin expression and decreased expression of vimentin, Smad4, c‐Myc, Snail1 and SLUG. In conclusion, the overexpression of miR‐539‐mediated DLX1 inhibition could potentially impede EMT, proliferation, migration and invasion of PCa cells through the blockade of the TGF‐β/Smad4 signalling pathway, highlighting a potential miR‐539/DLX1/TGF‐β/Smad4 regulatory axis in the treatment of PCa.

MicroRNA‑539 inhibits the proliferation and migration of gastric cancer cells by targeting SRY‑box 5 gene

The aim of the present study was to investigate the effect of microRNA (miR)‑539 on the proliferation and migration of gastric cancer cells, and explore the underlying mechanism. Gastric cancer cell lines with high or low miR‑539 and SRY‑box 5 (SOX5) expression levels were constructed by transfection. The proliferation of gastric cancer cells was then detected by Cell Counting Kit‑8 assay and cell migration was tested by transwell assay. The results revealed low expression of miR‑539 and high expression of SOX5 in gastric cancer tissues and cells as compared with the levels in normal tissues and cells, suggesting that there was a negative correlation between miR‑539 and SOX5. Dual‑luciferase reporter experiments demonstrated that miR‑539 directly targeted SOX5. The proliferation and migration of gastric cancer cells were negatively regulated by the overexpression of miR‑539, while positively regulated by the overexpression of SOX5. Notably, SOX5 overexpression attenuated the inhibitory effect of miR‑539 on gastric cancer cells. The results suggested that SOX5 is a target gene of miR‑539, and that miR‑539 inhibits the proliferation and migration of gastric cancer cells by targeting SOX5.

microRNA-539 functions as a tumor suppressor in papillary thyroid carcinoma via the transforming growth factor β1/Smads signaling pathway by targeting secretory leukocyte protease inhibitor

Papillary thyroid carcinoma (PTC) is the most common type of thyroid malignancy, with growing incidence every year. microRNAs (miRs) are known to regulate the physiological and pathological processes of cancers, such as proliferation, migration, invasion, survival, and epithelial-mesenchymal transition (EMT). Herein, this study aimed to investigate the effect of miR-539 on cell proliferation, apoptosis, and EMT by targeting secretory leukocyte protease inhibitor (SLPI) via the transforming growth factor β1 (TGF-β1)/Smads signaling pathway in PTC. First, PTC-related differentially expressed genes and regulatory miR were screened using bioinformatics analysis, dual luciferase reporter gene assay, and ribonucleoprotein immunoprecipitation, which identified the SLPI gene and the regulatory miR-539 for this study. We identified SLPI as a highly expressed gene in PTC tissues, and SLPI was targeted and negatively regulated by miR-539. Then, we introduced a series of miR-539 mimics, miR-539 inhibitors, and small interfering RNA against SLPI plasmids into CGTHW-3 cells to examine the effects of miR-539 and SLPI on the expression of TGF-β1/Smads signaling pathway-, EMT-, and apoptosis-related factors, as well as cell proliferation, migration, invasion, and apoptosis. The obtained results indicated that CGTHW-3 cells treated with silenced SLPI or overexpressed miR-539 suppressed the cell proliferation, migration, invasion abilities, and resistance to apoptosis of PTC cells, corresponding to increased expression of Bcl-2-associated X protein, TGF-β1, Sekelsky mothers against dpp 4, and epithelial cadherin, and decreased B cell lymphoma 2, Vimentin, and N-cadherin. Altogether, we concluded that overexpressed miR-539 could inhibit the PTC cell proliferation and promote apoptosis and EMT by targeting SPLI via activation of the TGF-β1/Smads signaling pathway.

Down-regulation of MiR-539 Indicates Poor Prognosis in Patients with Pancreatic Cancer

It has been demonstrated that miR-539 plays an important role in the development and progression of tumors. The purpose of this study was to analyze the correlation between the expression level of miR-539 and the clinicopathological features and prognosis of patients with pancreatic cancer. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the expression level of miR-539 in 60 patients with pancreatic cancer. It was found that miR-539 gene expression was down-regulated in pancreatic cancer compared with that in paracancerous tissues. In addition, the expression level of miR-539 was inversely correlated with tumor differentiation (poorly to moderately differentiated vs. well differentiated, P=0.006), lymph node metastasis (positive vs. negative, P=0.006), clinical stage (III-IV vs. I-II, P=0.002), CA199 (≥200 vs. <200, P=0.019) and distant metastasis (positive vs. negative, P=0.035). The survival time of pancreatic cancer patients with low expression of miR-539 was significantly shorter than that of patients with high expression of miR-539. Multivariate analysis suggested that miR-539 expression level was an independent prognostic indicator for patients with pancreatic cancer (P=0.025). Down-regulation of miR-539 may be a potentially unfavorable prognostic factor for patients with pancreatic cancer, and further studies are needed to confirm our conclusion in the future.

RETRACTED: miR-539 enhances chemosensitivity to cisplatin in non-small cell lung cancer by targeting DCLK1

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. An Expression of Concern for this article was previously published while an investigation was conducted (see related editorial: https://doi.org/10.1016/j.biopha.2022.113812). This retraction notice supersedes the Expression of Concern published earlier. Concern was raised about the reliability of the flow cytometry data in Figures 2C, 3C and 6C, which appear to contain similar features as found in other publications, as detailed here: https://pubpeer.com/publications/96CACC6C7EAE327217D2319DC364C5; and here: https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. Examples of suspected image duplication were also identified in Figures 4A+B, 6E+F, 7C. The journal requested the corresponding author comment on these concerns and provide the associated raw data. The authors did not respond to this request and therefore the Editor-in-Chief decided to retract the article.

MicroRNA‑539 inhibits cell proliferation, colony formation and invasion in pancreatic ductal adenocarcinoma by directly targeting IGF‑1R

MicroRNAs (miRNAs) possess oncogenic and tumour‑suppressive roles in the carcinogenesis and progression of pancreatic ductal adenocarcinoma (PDAC) by regulating the expression of numerous cancer‑related genes. Thus, the investigation on the expression and roles of miRNAs in PDAC may facilitate the identification of novel and effective targets for the clinical diagnosis and treatment of patients with PDAC. miRNA‑539 (miR‑539) has been studied in multiple types of human cancer. However, its expression and potential biological function in PDAC remain unclear. In the current study, the expression level, clinical significance, roles and underlying molecular mechanism of miR‑539 in PDAC. The present results demonstrated that miR‑539 expression was downregulated in PDAC tissues and cell lines. A low miR‑539 level was associated with TNM stage and lymph node metastasis of patients with PDAC. miR‑539 overexpression induced a significant reduction in the proliferation, colony formation and invasion of PDAC cells. Insulin‑like growth factor 1 receptor (IGF‑1R) was confirmed as a direct target gene of miR‑539 in PDAC. Further analysis indicated that IGF‑1R was overexpressed in PDAC tissues. Notably, the mRNA expression of IGF‑1R was negatively correlated with miR‑539 levels in PDAC tissues. In addition, the recovered IGF‑1R expression also partially counteracted the suppressive roles of miR‑539 overexpression in PDAC cells. Overall, miR‑539 may inhibit the aggressive behaviour of PDAC by directly targeting IGF‑1R and may serve as a novel therapeutic target for patients with this disease.

MicroRNA-539 promotes osteoblast proliferation and differentiation and osteoclast apoptosis through the AXNA-dependent Wnt signaling pathway in osteoporotic rats

This study aims to explore the effects of miR-539 on osteoblast proliferation and differentiation and osteoclast apoptosis in a rat model of osteoporosis, and its mechanism involving the regulation of the AXIN1-mediated wingless-Int (Wnt) signaling pathway. A rat model of osteoporosis was successfully established by ovariectomy. With osteoblasts and osteoclasts of rats not receiving ovariectomy in the sham group as control, those of osteoporotic rats were treated with miR-539 inhibitor, miR-539 mimic, and AXIN1 shRNA. The expression of miR-53, AXIN1, the Wnt pathway related-genes, apoptosis related-genes, and osteogenic markers were measured by RT-qPCR and Western blot analysis, respectively. Alkaline phosphatase (ALP) activity in osteoblast and tartrate-resistant acid phosphatase (TRAP) activity in osteoclasts were determined after cell transfection. Osteoblast and osteoclast viability was assayed by CCK-8 assay. Cell cycle and apoptosis of osteoblasts and osteoclasts were detected by flow cytometry. Lastly, alizarin red S staining was used to detect mineralized nodules of osteoblasts. Firstly, we determined that miR-539 was down-regulated in osteoblast and osteoclast of osteoporotic rats and AXIN1 was negatively regulated by miR-539. Additionally, overexpression of miR-539 increased the expressions of β-catenin, LEF1, c-myc, cyclin D1, RUNX2, BGP, BMP-2 in osteoblast as well as β-catenin, RhoA, caspase-3, and Bcl-2 in osteoclasts. Finally, overexpression of miR-539 elevated ALP activity, proliferation, and mineralized nodules in osteoblast and osteoclast apoptosis, with reduced TRAP activity in osteoclasts. Our results demonstrate that miR-539 promotes osteoblast proliferation and differentiation as well as osteoclast apoptosis through the AXIN1-dependent Wnt signaling pathway in osteoporotic rats.

MicroRNA-539 inhibits colorectal cancer progression by directly targeting SOX4

Colorectal cancer (CRC) is the third most prevalent cancer and the fourth most common cause of cancer-associated mortality in males and females globally. Aberrant expression of microRNA-539 (miR-539) has been reported in multiple types of cancer. However, miR-539 expression, function and underlying mechanisms have not been clearly elucidated in CRC. In the present study, miR-539 expression was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in CRC tissues and cell lines. The effects of miR-539 on CRC cells were further examined in in vitro studies. In addition, the direct targets of miR-539 in CRC were investigated using bioinformatics, luciferase reporter assays, RT-qPCR and western blotting. miR-539 was revealed to be significantly downregulated in CRC cell lines and tissues. Decreased miR-539 expression was associated with lymph node metastasis and tumor-node-metastasis stage in patients with CRC. Functional assays revealed that the rescue of miR-539 expression attenuated CRC cell proliferation and invasion in vitro. Additionally, SRY-box 4 (SOX4) was validated as a direct target gene of miR-539 in CRC. Furthermore, SOX4 was revealed to be upregulated in CRC tissues at the mRNA and protein level. A significant negative correlation between miR-539 and SOX4 mRNA expression levels was observed in CRC tissues. Furthermore, upregulation of SOX4 partially restored the tumor suppressive effects of miR-539 on CRC cell proliferation and invasion. Taken together, this suggests that miR-539 may serve tumor-suppressive functions in CRC during the process of malignant transformation, by directly targeting SOX4. miR-539/SOX4-based targeted therapy may represent a potential novel treatment for patients with CRC.

MicroRNA‑539 inhibits the proliferation and invasion of bladder cancer cells by regulating IGF‑1R

Bladder cancer is the most frequent malignancy of the urinary tract and the seventh most common cancer worldwide. The abnormal expression of microRNAs has been frequently observed in various types of human cancers, including bladder cancer. In addition, an increasing body of evidence has demonstrated that microRNAs are potential targets for cancer diagnosis, treatments and prognosis. The aim of the present study was to investigate the expression patterns and potential roles of microRNA‑539 (miR‑539) in bladder cancer and its underlying mechanism. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was performed to detect miR‑539 expression in the bladder cancer tissues and cell lines. Following transfection, MTT and cell invasion assays were used to investigate the effects of miR‑539 overexpression or IGF1R underexpression on bladder cancer cell proliferation and invasion. Bioinformatics analysis, a luciferase reporter assay, RT‑qPCR and western blot analysis were utilized to determine the potential targets of miR‑539 in bladder cancer. The results revealed that miR‑539 levels were relatively decreased in bladder cancer tissues and cell lines when compared with those observed in the matched adjacent normal bladder tissues and normal bladder epithelial cell line. miR‑539 expression was associated with the tumor stage and lymph node metastasis of patients with bladder cancer. In addition, the expression of miR‑539 suppressed bladder cancer cell proliferation and invasion. Insulin like growth factor 1 receptor (IGF‑1R) was identified as a direct target of miR‑539, and miR‑539 was also observed to regulate the protein kinase B and extracellular signal‑regulated kinases signaling pathways. IGF‑1R was markedly upregulated in bladder cancer tissues and negatively associated with miR‑539 expression levels. Furthermore, IGF‑1R knockdown in bladder cancer cells significantly inhibited cell proliferation and invasion. To the best of our knowledge, these results demonstrated for the first time that miR‑539 may act as a tumor suppressor and serve important roles in tumorigenesis and progression of bladder cancer. Thus, miR‑539/IGF‑1R may be a potential therapeutic target for the treatment of bladder cancer.

miR-539 acts as a tumor suppressor by targeting epidermal growth factor receptor in breast cancer

Breast cancer is the most frequently diagnosed malignancy and the leading cause of cancer-associated death in women worldwide. microRNAs (miRNAs) play critical roles in the cellular processes of breast cancer. However, the crucial roles and underlying mechanisms of miR-539 in breast cancer remain unclear. By RT-qPCR, we found that expression of miR-539 was markedly down-regulated in breast cancer tissues and cell lines compared with that in paired adjacent normal tissues and normal cell lines. The low level of miR-539 expression was positively associated with lymph node metastasis. Furthermore, forced expression of miR-539 inhibited proliferation and migration of breast cancer MDA-MB-231 and MCF7 cells in vitro and suppressed tumor growth in vivo. Moreover, bioinformatics analysis and luciferase reporter assays indicated that epidermal growth factor receptor (EGFR) was a direct target of miR-539. Over-expression of miR-539 decreased the EGFR mRNA and protein levels in MDA-MB-231 and MCF7 cells. In addition, ectopic over-expression of EGFR partly reversed miR-539-inhibited proliferation as well as migration of MDA-MB-231 and MCF7 cells. Taken together, our results demonstrate that miR-539 functions as a tumor suppressor in breast cancer by downregulating EGFR, supporting the targeting of the novel miR-539/EGFR axis as a potentially effective therapeutic approach for breast cancer.

Long Non-coding RNA LINC00339 Stimulates Glioma Vasculogenic Mimicry Formation by Regulating the miR-539-5p/TWIST1/MMPs Axis

Glioma is recognized as a highly angiogenic malignant brain tumor. Vasculogenic mimicry (VM) greatly restricts the therapeutic effect of anti-angiogenic tumor therapy for glioma patients. However, the molecular mechanisms of VM formation in glioma remain unclear. Here, we demonstrated that LINC00339 was upregulated in glioma tissue as well as in glioma cell lines. The expression of LINC00339 in glioma tissues was positively correlated with glioma VM formation. Knockdown of LINC00339 inhibited glioma cell proliferation, migration, invasion, and tube formation, meanwhile downregulating the expression of VM-related molecular MMP-2 and MMP-14. Furthermore, knockdown of LINC00339 significantly increased the expression of miR-539-5p. Both bioinformatics and luciferase reporter assay revealed that LINC00339 regulated the above effects via binding to miR-539-5p. Besides, overexpression of miR-539-5p resulted in decreased expression of TWIST1, a transcription factor known to play an oncogenic role in glioma and identified as a direct target of miR-539-5p. TWIST1 upregulated the promoter activities of MMP-2 and MMP-14. The in vivo study showed that nude mice carrying tumors with knockdown of LINC00339 and overexpression of miR-539-5p exhibited the smallest tumor volume through inhibiting VM formation. In conclusion, LINC00339 may be used as a novel therapeutic target for VM formation in glioma.

Role of microRNAs in endocrine cancer metastasis

The deregulation of transcription and processing of microRNAs (miRNAs), as well as their function, has been involved in the pathogenesis of several human diseases, including cancer. Despite advances in therapeutic approaches, cancer still represents one of the major health problems worldwide. Cancer metastasis is an aggravating factor in tumor progression, related to increased treatment complexity and a worse prognosis. After more than one decade of extensive studies of miRNAs, the fundamental role of these molecules in cancer progression and metastasis is beginning to be elucidated. Recent evidences have demonstrated a significant role of miRNAs on the metastatic cascade, acting either as pro-metastatic or anti-metastatic. They are involved in distinct steps of metastasis including epithelial-to-mesenchymal transition, migration/invasion, anoikis survival, and distant organ colonization. Studies on the roles of miRNAs in cancer have focused mainly on two fronts: the establishment of a miRNA signature for different tumors, which may aid in early diagnosis using these miRNAs as markers, and functional studies of specific miRNAs, determining their targets, function and regulation. Functional miRNA studies on endocrine cancers are still scarce and represent an important area of research, since some tumors, although not frequent, present a high mortality rate. Among the endocrine tumors, thyroid cancer is the most common and best studied. Several miRNAs show lowered expression in endocrine cancers (i.e. miR-200s, miR-126, miR-7, miR-29a, miR-30a, miR-137, miR-206, miR-101, miR-613, miR-539, miR-205, miR-9, miR-195), while others are commonly overexpressed (i.e. miR-21, miR-183, miR-31, miR-let7b, miR-584, miR-146b, miR-221, miR-222, miR-25, miR-595). Additionally, some miRNAs were found in serum exosomes (miR-151, miR-145, miR-31), potentially serving as diagnostic tools. In this review, we summarize studies concerning the discovery and functions of miRNAs and their regulatory roles in endocrine cancer metastasis, which may contribute for the finding of novel therapeutic targets. The review focus on miRNAs with at least some identified targets, with established functions and, if possible, upstream regulation.

Long non-coding RNA LOC100129148 functions as an oncogene in human nasopharyngeal carcinoma by targeting miR-539-5p

Emerging studies have shown that long noncoding RNAs (lncRNAs) play critical roles in carcinogenesis and progression, including human nasopharyngeal carcinoma (NPC). The correlation between lncRNAs expression and NPC development has not been well identified in the recent literature. Recently, high-through put analysis reveals that LOC100129148 is highly expressed in NPC. However, whether the aberrant expression of LOC100129148 in NPC is corrected with tumorigenesis or prognosis has not been investigated. Herein, we identified that LOC100129148 was up-regulated in NPC tissues and cell lines, and higher expression of LOC100129148 resulted in a markedly poorer survival time. Over-expressed LOC100129148 favored, but silenced LOC100129148 hampered cell proliferation in NPC cells. Additionally, LOC100129148 enhanced the KLF12 expression through functioning as a competitive 'sponge' for miR-539-5p. Thus, our study reports a novel mechanism underlying NPC carcinogenesis, and provides a potential novel diagnosis and treatment biomarker for NPC.

miR-539 inhibits human colorectal cancer progression by targeting RUNX2

Emerging evidence has shown that microRNAs (miRNAs) such as miR-539 play critical roles in carcinogenesis and progression in many types of cancer, including human colorectal cancer (CRC). However, the roles and underlying mechanism of miR-539 in CRC have not been well identified. The aims of this study were, therefore, to investigate the regulatory role and potential mechanism of miR-539 in human CRC. Here, we show that miR-539 expression is downregulated in CRC tissues and cell lines. The expression level of miR-539 is inversely associated with advanced clinical stage and lymph node metastasis. In vitro studies reveal that overexpression of miR-539 inhibits CRC cell proliferation and colony formation as well as migration and invasion; in vivo results demonstrate that overexpression of miR-539 dramatically reduces CRC xenograft tumor growth. Moreover, runt-related transcription factor 2 (RUNX2), a known oncogene, was identified as a target transcript of miR-539 in CRC by bioinformatic analysis, luciferase reporter assay, qPCR, and western blotting. RUNX2 expression levels were upregulated and inversely correlated with miR-539 expression in CRC tissues. Importantly, overexpression of RUNX2 without the 3'-untranslated region that is targeted by miR-539 partially reversed the inhibitory effect of miR-539 on CRC cell proliferation, migration, and invasion. Collectively, these findings demonstrate that miR-539 functions as a tumor suppressor in CRC, at least in part, by targeting RUNX2, supporting the targeting of the novel miR-539 as a potentially effective therapeutic approach for treatment of CRC.

miR-539 mediates osteoblast mineralization by regulating Distal-less genes 2 in MC3T3-E1 cell line

microRNAs (miRNAs) play an important role in osteoblast differentiation. However, the mechanisms of miRNAs regulating osteoblast mineralization still needs to be further cleared. Distal-less genes 2 (Dlx2) plays an important role in osteoblast differentiation. We have found that miR-539 was significantly downregulated and Dlx2 was found to be inversely correlated with miR-539 in MC3T3-E1 cell line during osteoblast mineralization. The overexpression of miR-539 significantly decreased the expression level of Dlx2 and suppressed the osteogenic marker gene expression level, alkaline phosphatase activity and matrix mineralization. Our study showed that miR-539 was a negative regulator in osteoblast mineralization and that the targeting of Dlx2 gene partly contributes to this inhibitory effect exerted by miR-539.

[ARTICLE WITHDRAWN] MicroRNA-539 Inhibits the Epithelial-Mesenchymal Transition of Esophageal Cancer Cells by Twist-Related Protein 1-Mediated Modulation of Melanoma-Associated Antigen A4

This article has been withdrawn at the request of the publisher in December 2020.

miR-539 inhibits FSCN1 expression and suppresses hepatocellular carcinoma migration and invasion

Increasing evidence indicates that the dysregulation of miRNAs that act as tumor suppressors or oncogenes is involved in tumorigenesis. However, the role of miR-539 in hepatocellular carcinoma (HCC) has not been well investigated. Quantitative RT-PCR (qRT-PCR), proliferation assay, colony formation assay, migration and invasion assays, western blotting, and xenograft tumor growth models were performed to assess the expression levels and functions of miR-539 in HCC. Luciferase reporter assays, qRT-PCR, western blotting, and immunohistochemistry were used to identify and verify the targets of miR-539. miR-539 was significantly downregulated in HCC cell lines and tissue samples. Ectopic expression of miR-539 inhibited cell viability, proliferation, migration, and invasion in vitro and suppressed xenograft tumor growth in vivo. Fascin homologue 1 (FSCN1) was verified as a direct target of miR-539, and overexpression of FSCN1 promoted HCC cell migration and invasion. miR-539 acts as a novel tumor suppressor in the development and progression of HCC by targeting FSCN1, providing new insight into the mechanisms of HCC carcinogenesis and suggesting that miR-539 may be a therapeutic target.

miRNA dysregulation and the risk of metastasis and invasion in papillary thyroid cancer: a systematic review and meta-analysis

Thyroid cancer (TC) is the most common endocrine malignancy, with an incidence continuing to grow every year. Although thyroid cancer as a whole is generally indolent and relatively easy to treat, some subtypes carry a higher rate of metastasis and cancer-related mortality. A growing number of studies have focused on the dysregulation of miRNAs in TC. However, differences in methods make comparison of gene profiling data difficult. A meta-analysis of published studies comparing miRNA expression data of invasive thyroid carcinoma with paired non-invasive tumors or normal tissues was performed by searching the literature for “invasion”, “thyroid cancer”, and “miRNA”. This revealed 29 dysregulated miRNAs associated with TC in 16 articles; the presence of invasion was confirmed in each respective article by laboratory research or patient follow-up. Among these miRNAs, miRNA-146b, miRNA-221, and miRNA-222 were analyzed further due to their higher frequencies across multiple studies. Of these studies, 6 were included in the meta-analysis, as they compared invasive PTC with paired normal tissues or non-invasive PTC.

MicroRNA-463-3p/ABCG4: A new axis in glucose-stimulated insulin secretion

OBJECTIVE

Glucose-stimulated insulin secretion (GSIS) is known to be essential in the control of metabolic fuel homeostasis, though the molecular mechanisms involved remain unclear.

METHODS

MicroRNA (miRNA)-463-3p and ATP-binding cassette A4 (ABCG4) expression was analyzed by real-time PCR, and the potential role of miRNA-463-3p or ABCG4 was evaluated by overexpressing or silencing such miRNA or genes.

RESULTS

The miRNA-463-3p inhibited GSIS without affecting cell viability. Further, mechanistic studies demonstrated that ABCG4 was a direct target of microRNA-463-3p and, to this effect, that ABCG4 played an important role in GSIS. The targeting was relevant in pancreatic islet β-cells, where GSIS through the miRNA-463-3p/ABCG4 axis was observed. Interestingly, in type 2 diabetes human pancreatic islets, expression of miRNA-463-3p and insulin was upregulated and ABCG4 downregulated compared with nondiabetic controls, and their expression levels were closely correlated.

CONCLUSIONS

The findings collectively establish a link between GSIS and the miRNA-463-3p/ABCG4 axis and represent a promising target for future diabetes mellitus treatments.

microRNA-539 suppresses tumor growth and tumorigenesis and overcomes arsenic trioxide resistance in hepatocellular carcinoma

AIMS

Dysregulation of microRNAs (miRNAs) plays a critical role in tumor growth and progression. In this study, we sought to explore the expression and biological roles of miR-539 in hepatocellular carcinoma (HCC).

MAIN METHODS

The expression of miR-539 in human HCC tissues and cell lines was examined. The effects of miR-539 overexpression on cell growth, tumorigenicity, arsenic trioxide resistance of HCC cells were determined. The signaling pathways involved in the action of miR-539 in HCC were also investigated.

KEY FINDINGS

miR-539 was downregulated in HCC tissues and cells, relative to corresponding controls. Overexpression of miR-539 inhibited HCC cell viability and colony formation in vitro and impaired tumorigenesis of HCC cells in vivo. Transfection with miR-539 mimic significantly induced apoptosis in HepG2 cells, which was coupled with reduced expression of anti-apoptotic proteins Bcl-2 and Bcl-xL and decreased phosphorylation of Stat3. Overexpression of a constitutively active form of Stat3 partially blocked miR-539-mediated apoptosis. Enforced expression of miR-539 resensitized arsenic trioxide-resistant HCC cells to arsenic trioxide. Intratumoral delivery of miR-539 mimic significantly retarded the growth of xenograft tumors from arsenic trioxide-resistant HCC cells by about 35%, compared to delivery of control miRNA (P<0.05). In combination with arsenic trioxide, miR-539 mimic yielded about 80% decrease in tumor burden.

SIGNIFICANCE

miR-539 functions as a tumor suppressor in HCC and reexpression of this miRNA offers a potential therapeutic strategy for this disease.

miR-539 inhibits prostate cancer progression by directly targeting SPAG5

Background

We conducted multiple microarray datasets analyses from clinical and xenograft tumor tissues to search for disease progression-driving oncogenes in prostate cancer (PCa). Sperm-associated antigen 5 (SPAG5) attracted our attention. SPAG5 was recently identified as an oncogene participating in lung cancer and cervical cancer progression. However, the roles of SPAG5 in PCa progression remain unknown.

Methods

SPAG5 expression level in clinical primary PCa, metastatic PCa, castration resistant PCa, neuroendocrine PCa, and normal prostate tissues was investigated. We established multiple in vivo xenografts models using patient-derived tissues and investigated SPAG5 expression trend in these models. We also investigated the functions of SPAG5 in vivo and in vitro studies. Luciferase reporter assays were performed to investigate potential miRNAs that can regulate SPAG5.

Results

We identified that SPAG5 expression was gradually increased in PCa progression and its level was significantly associated with lymph node metastasis, clinical stage, Gleason score, and biochemical recurrence. Our results indicated that SPAG5 knockdown can drastically inhibit PCa cell proliferation, migration, and invasion in vitro and supress tumor growth and metastasis in vivo. We identified that miR-539 can directly target SPAG5. Ectopic overexpression of miR-539 can drastically inhibit SPAG5 expression and the restoration of SPAG5 expression can reverse the inhibitory effects of miR-539 on PCa cell proliferation and metastasis.

Conclusion

Our results collectively showed a progression-driving role of SPAG5 in PCa which can be regulated by miR-539, suggesting that miR-539/SPAG5 can serve as a potential therapeutic target for PCa.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0337-8) contains supplementary material, which is available to authorized users.

Down-regulation of miR-133a and miR-539 are associated with unfavorable prognosis in patients suffering from osteosarcoma

Background

MicroRNAs (miRNAs) play key roles in cancer development and progression. The purpose of the present study was to determine the expression levels of miR-133a and miR-539 in osteosarcoma patients and to further investigate the clinicopathological, and prognostic value of these miRNAs.

Methods

The expression levels of miR-133a and miR-539 were determined by qRT-PCR. Associations between miRNAs expressions and various clinicopathological characteristics were analyzed. Survival rate was determined with Kaplan–Meier and statistically analyzed with the log-rank method between groups. Survival data were evaluated through multivariate Cox regression analysis

Results

Our findings revealed that the miR-133a expression was significantly decreased in clinical osteosarcoma tissues compared to adjacent normal bone tissues. The expression level of miR-539 was decreased in clinical osteosarcoma tissues as compared to those adjacent normal tissues. Low expressions of miR-133a and miR-539 were significantly association with advanced TNM stage (P = 0.002; P = 0.001), and metastasis or recurrence (P = 0.001; P = 0.01). Furthermore, Kaplan–Meier survival analysis and log-rank test showed that the low expressions of miR-133a and miR-539 were correlated with the reduced overall survival of osteosarcoma patients. Multivariate Cox proportional hazards model showed that decreased expressions of miR-133a and miR-539 (P = 0.007; P = 0.02), TNM stage (P = 0.001; P = 0.002), and metastasis or recurrence (P = 0.005; P = 0.026) were independent prognostic markers of overall survival of patients.

Conclusion

These results suggest that decreased miR-133a and miR-539 expressions may participate in the progression of osteosarcoma. Together, these results showed that miR-133a and miR-539 may have their role in both progression and prognosis of osteosarcoma.