Investigating changes in the post-transcriptional pattern of VEGF and CD146 genes carrying miR-573 in breast cancer cells treated with tamoxifen.

BACKGROUND: Recent developments regarding the contribution of microRNAs (miRNAs) to tumor angiogenesis and the oncogenic effects of miRNAs point to their potential role in breast cancer angiogenesis. Tumor-derived exosomes are considered a rich source of miRNAs that can regulate the function of other cells in the tumor microenvironment, including vascular endothelial cells. This study analyzes the effect of tamoxifen chemotherapy on the expression of a key miRNA, miR-573, involved in the angiogenesis of the tumor exosomes and introduces a regulatory link between this miRNA and the CD146 gene associated with the vascular endothelial growth factor (VEGF) messaging pathway. MATERIALS AND METHODS: MCF-7 breast cancer cells were purchased and cultured in a complete culture medium. These cells were treated with tamoxifen and then their exosomes were extracted from the culture medium. The RNAs of the exosomes were isolated and the expression of miR-573, VEGF, and CD146 genes in the exosomes was investigated using the real-time polymerase chain reaction (PCR) method. RESULTS: The results of this study showed that tamoxifen treatment increased the expression of miR-573 in exosomes derived from MCF-7 cancer cells. The expression of CD146 and VEGF genes in drug-treated cell exosomes had a downward pattern. CONCLUSION: The results of this experiment demonstrated that the treatment of breast cancer cells with tamoxifen reduces the expression of VEGF and CD146 by increasing miR-573. Thus, angiogenesis is reduced and, therefore, its anti-tumor effects are applied.

MicroRNA 573 Rescues Endothelial Dysfunction during Dengue Virus Infection under PPARγ Regulation.

Early prognosis of abnormal vasculopathy is essential for effective clinical management of patients with severe dengue. An exaggerated interferon (IFN) response and release of vasoactive factors from endothelial cells cause vasculopathy. This study shows that dengue virus 2 (DENV2) infection of human umbilical vein endothelial cells (HUVEC) results in differentially regulated microRNAs (miRNAs) important for endothelial function. miR-573 was significantly downregulated in DENV2-infected HUVEC due to decreased peroxisome proliferator activator receptor gamma (PPARγ) activity. Restoring miR-573 expression decreased endothelial permeability by suppressing the expression of vasoactive angiopoietin 2 (ANGPT2). We also found that miR-573 suppressed the proinflammatory IFN response through direct downregulation of Toll-like receptor 2 (TLR2) expression. Our study provides a novel insight into miR-573-mediated regulation of endothelial function during DENV2 infection, which can be further translated into a potential therapeutic and prognostic agent for severe dengue patients. IMPORTANCE We need to identify molecular factors that can predict the onset of endothelial dysfunction in dengue patients. Increase in endothelial permeability during severe dengue infections is poorly understood. In this study, we focus on factors that regulate endothelial function and are dysregulated during DENV2 infection. We show that miR-573 rescues endothelial permeability and is downregulated during DENV2 infection in endothelial cells. This finding can have both diagnostic and therapeutic applications.

MiR-573 suppresses cell proliferation, migration and invasion via regulation of E2F3 in pancreatic cancer.

Background: Pancreatic cancer is among the most lethal malignancies worldwide. In this study, we aimed to determine whether miR-573 could suppress pancreatic cancer cell proliferation, migration, and invasion by targeting E2F3. Materials and Methods: MiR-573 expression in pancreatic cancer tissues and cell lines was measured using real-time PCR. Target genes of miR-573 were screened using bioinformatics tools and confirmed using dual-luciferase reporter assay and real-time PCR. Pancreatic cancer cells were transfected using an miR-573 mimic or siRNA E2F3. Furthermore, cell proliferation, migration, and invasion were assessed using CCK-8, Edu staining, colony-forming assay, wound healing assay, and transwell assay in vitro. The in vivo effects of miR-573 were verified using tumor xenografts. Differential expression and prognostic analyses of miR-573 and E2F3 were visualized using the Kaplan­Meier plotter and GEPIA. Results: We found that the expression of miR-573 was significantly reduced in pancreatic cancer tissues and cell lines. Overexpression of miR-573 obviously suppressed the proliferation, migration, and invasion of pancreatic cancer cells. The Dual-luciferase assay showed that miR-573 could specifically target E2F3. Furthermore, E2F3 was up-regulated in pancreatic cancer tissues and cell lines and E2F3 down-regulation inhibited the proliferation, migration, and invasion of pancreatic cancer cells. The ectopic expression of miR-573 inhibited xenograft tumor growth in vivo. Results from the Kaplan-Meier analysis and GEPIA showed that patients with a high level of miR-573 had a significantly reduced risk of death while those with a high level of E2F3 displayed significant correlation with the tumor stage and suffered worse prognosis. Conclusions: MiR-573 could suppress the proliferation, migration, and invasion of pancreatic cancer cells by targeting E2F3, thereby establishing miR-573 as a novel regulator of E2F3 and indicating its critical role in tumorigenesis, especially in pancreatic cancer.

Circular RNA circ_0079593 enhances malignant melanoma progression by the regulation of the miR-573/ABHD2 axis.

BACKGROUND: Malignant melanoma is the most fatal type of skin tumor. Circular RNAs (circRNAs) have been implicated in the malignant progression of melanoma. OBJECTIVE: The main purpose of this paper was to identify the precise parts of circ_0079593 in the malignant progression of melanoma. METHODS: The levels of circ_0079593, miR-573 and abhydrolase domain containing 2 (ABHD2) were determined by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Cell proliferation, colony formation, cell cycle progression, apoptosis, migration, and invasion were evaluated using the Cell Counting Kit-8 (CCK-8), colony formation, flow cytometry, and transwell assays, respectively. Targeted correlations among circ_0079593, miR-573 and ABHD2 were confirmed by dual-luciferase reporter, RNA immunoprecipitation (RIP) and RNA pull-down assays. Animal studies were performed to assess the role of circ_0079593 in vivo. RESULTS: Our data showed that circ_0079593 level was up-regulated in melanoma tissues and cells. The knockdown of circ_0079593 suppressed cell proliferation, cell cycle progression, migration, invasion, and enhanced apoptosis in vitro and inhibited tumor growth in vivo. Mechanistically, circ_0079593 directly targeted miR-573, and circ_0079593 controlled ABHD2 expression by miR-573. MiR-573 mediated the regulation of circ_0079593 on melanoma cell progression in vitro. Moreover, ABHD2 was a functional target of miR-573 in regulating melanoma cell progression in vitro. CONCLUSION: Our findings identified that the knockdown of circ_0079593 suppressed melanoma progression at least partially through targeting the miR-573/ABHD2 axis, providing evidence for developing circ_0079593 as a promising therapeutic target for melanoma treatment.

miR-573 suppresses pancreatic cancer cell proliferation, migration, and invasion through targeting TSPAN1.

PURPOSE: To explore whether miR-573 can suppress pancreatic cancer cell proliferation, migration, and invasion by targeting TSPAN1. METHODS: The expression of miR-573 and TSPAN1 in pancreatic cancer tissues and cells lines was analyzed using RT-qPCR. The human pancreatic cancer cell line PANC­1 was transfected with miR-573 mimic, pcDNA3.1-TSPAN1, or genOFFTM st-h-TSPAN1. The effects of miR-573 and TSPAN1 on cell proliferation, colony formation, migration, and invasion were analyzed by CCK­8, colony formation, transwell migration, and invasion assay, respectively. Target genes of miR-573 were screened using bioinformatics tools and confirmed by dual-luciferase reporter assay and real-time PCR. The effects of miR-573 in vivo were observed using tumor xenografts. RESULTS: We found that miR-573 is downregulated and TSPAN1 is upregulated in pancreatic cancer tissues and cells lines. Function assays demonstrated that overexpression of miR-573 inhibited cell proliferation, colony formation, migration, and invasion of pancreatic cancer cells, as well as suppressing tumor growth in vivo. Target genes of miR-573 were predicted using bioinformatics tools and confirmed by dual-luciferase reporter assay and RT-qPCR or western blotting. Downregulation of TSPAN1 also inhibited cell proliferation, colony formation, migration, and invasion of pancreatic cancer cells. Furthermore, overexpression of TSPAN1 attenuated miR-573-induced inhibition of pancreatic cancer cell proliferation and migration. CONCLUSION: Our findings indicated that miR-573 suppresses pancreatic cancer cell proliferation, migration, and invasion through targeting TSPAN1. TSPAN1 targeted by miR-573 might be a potential therapeutic target for clinical treatment of pancreatic cancer.

miR-573 regulates cell proliferation and apoptosis by targeting Bax in nucleus pulposus cells.

BACKGROUND: MicroRNA (miRNA) plays a vital role in the pathogenesis of intervertebral disc degeneration (IDD). The expression and potential mechanism of miR-573 in human nucleus pulposus (NP) remains to be elucidated. In this study, we aimed to investigate the role of miR-573 in IDD. METHODS: Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis was applied to examine the expression of miR-573 and Bax in idiopathic scoliosis tissues and IDD tissues. Human NP cells were employed for analysis. Moreover, the proliferation and apoptosis of NP cells were detected using MTT and flow cytometry assay respectively. The expression levels of Bcl-2, cleaved caspase-3, cleaved caspase-9, caspase-3 and caspase-9 in degenerative NP cells were measured by Western blotting assay. Furthermore, a luciferase reporter assay was used to verify the relationship between miR-573 and Bax. RESULTS: The results revealed that the mRNA expression level of miR-573 was down-regulated whereas Bax was up-regulated notably in degenerative NP cells. In addition, overexpression of miR-573 increased cell viability remarkably, coupled with inhibition of cell apoptosis. The expression level of Bcl-2 was increased while cleaved caspase-3 and cleaved caspase-9 expression levels were decreased in miR-573 overexpression NP cells. Additionally, the bioinformatics analysis underscored that Bax was a direct target gene of miR-573. CONCLUSION: These results suggest that overexpression of miR-573 inhibited NP cell apoptosis by down-regulating Bax, which proved to be a novel effective strategy for IDD therapies.

Long non-coding RNA FLVCR1-AS1 contributes to the proliferation and invasion of lung cancer by sponging miR-573 to upregulate the expression of E2F transcription factor 3.

Lung cancer is one of the most common causes of cancer-related death all over the world. In recent years, long non-coding RNAs (lncRNAs) have been reported to play critical roles in the development and progression of human malignancies. In the present study, we aimed to study the role and mechanism of FLVCR1-AS1 in human non-small cell lung cancer (NSCLC). Results revealed that FLVCR1-AS1 was markedly upregulated in NSCLC tissues and cell lines. Knockdown of FLVCR1-AS1 significantly inhibited the proliferation, migration, invasion and promoted apoptosis of NSCLC cells, and suppressed tumor growth of NSCLC in vivo. Moreover, we explored regulatory mechanism, and found that FLVCR1-AS1 functioned as a competing endogenous RNA (ceRNA) by directly binding to miRNA-573, and E2F transcription factor 3 (E2F3) was identified as a down-stream target of miR-573. FLVCR1-AS1 positively regulated E2F3 expression through inhibiting miR-573 in NSCLC cells. Our findings suggested that FLVCR1-AS1/miR-573/E2F3 axis was an important signaling pathway in mediating tumorigenesis and progression of NSCLC, and further indicated that FLVCR1-AS1 could be a novel diagnostic biomarker and therapeutic target for NSCLC.

Long non-coding RNA TTN-AS1 promotes cell growth and metastasis in cervical cancer via miR-573/E2F3.

Long non-coding RNAs (lncRNAs) are a crucial member of non-coding RNA family, and increasing evidence demonstrates that lncRNAs participate in the initiation and progression of cancers. Our study aimed to explore the role of lncRNA TTN-AS1 in cervical cancer (CC) development. In the present study, our results showed that TTN-AS1 was substantially increased in CC tissues and cell lines, high expression of TTN-AS1 was correlated with advanced FIGO stage, poor differentiation, lymph node metastasis, and poor overall survival of CC patients. Function assays showed that TTN-AS1 inhibition decreased the proliferation and invasion of CC cells both in vitro and in vivo. Mechanistically, we revealed that TTN-AS1 could positively modulate E2F3 expression via sponging miR-573 in CC cells. Together, our study revealed that lncRNA TTN-AS1 was involved in the progression of CC cells by regulation of miR-573-E2F3 axis, which offered a new insight into the treatment strategies of CC.

MiR-573 inhibits prostate cancer metastasis by regulating epithelial-mesenchymal transition.

The metastastic cascade is a complex process that is regulated at multiple levels in prostate cancer (PCa). Recent evidence suggests that microRNAs (miRNAs) are involved in PCa metastasis and hold great promise as therapeutic targets. In this study, we found that miR-573 expression is significantly lower in metastatic tissues than matched primary PCa. Its downregulation is correlated with high Gleason score and cancer-related mortality of PCa patients (P = 0.041, Kaplan-Meier analysis). Through gain- and loss-of function experiments, we demonstrated that miR-573 inhibits PCa cell migration, invasion and TGF-ß1-induced epithelial-mesenchymal transition (EMT) in vitro and lung metastasis in vivo. Mechanistically, miR573 directly targets the fibroblast growth factor receptor 1 (FGFR1) gene. Knockdown of FGFR1 phenocopies the effects of miR-573 expression on PCa cell invasion, whereas overexpression of FGFR1 partially attenuates the functions of miR-573. Consequently, miR-573 modulates the activation of FGFR1-downstream signaling in response to fibroblast growth factor 2 (FGF2). Importantly, we showed that GATA3 directly increases miR-573 expression, and thus down-regulates FGFR1 expression, EMT and invasion of PCa cells in a miR-573-dependent manner, supporting the involvement of GATA3, miR-573 and FGFR1 in controlling the EMT process during PCa metastasis. Altogether, our findings demonstrate a novel mechanism by which miR-573 modulates EMT and metastasis of PCa cells, and suggest miR-573 as a potential biomarker and/or therapeutic target for PCa management.

TSPAN1 functions as an oncogene in gastric cancer and is downregulated by miR-573.

Tetraspanin 1 (TSPAN1) has been reported to be upregulated in gastric cancer (GC). However, whilst TSPAN1 is positively correlated with clinical stage and negatively correlated with survival rates, its function in GC remains elusive. Here we show that expression of TSPAN1 is significantly higher in GC tissues compared to non-cancerous tissues. Furthermore, we demonstrate that RNAi-mediated down-regulation of TSPAN1 expression markedly blocks GC cell proliferation, cell cycle progression and invasive activity. We identified TSPAN1 as a novel target gene of miR-573. Overexpression of miR-573 suppressed proliferation and invasion of GC cells by down-regulation of TSPAN1 expression. Restoration of TSPAN1 rescued the effects of miR-573 overexpression. Therefore, our findings suggest that the miR-573/TSPAN1 axis is important in the control of gastric carcinogenesis.

ADAR1 regulates ARHGAP26 gene expression through RNA editing by disrupting miR-30b-3p and miR-573 binding.

Rho GTPase activating protein 26 (ARHGAP26) is a negative regulator of the Rho family that converts the small G proteins RhoA and Cdc42 to their inactive GDP-bound forms. It is essential for the CLIC/GEEC endocytic pathway, cell spreading, and muscle development. The present study shows that ARHGAP26 mRNA undergoes extensive A-to-I RNA editing in the 3' UTR that is specifically catalyzed by ADAR1. Furthermore, the mRNA and protein levels of ARHGAP26 were decreased in cells in which ADAR1 was knocked down. Conversely, ADAR1 overexpression increased the abundance of ARHGAP26 mRNA and protein. In addition, we found that both miR-30b-3p and miR-573 target the ARHGAP26 gene and that RNA editing of ARHGAP26 mediated by ADAR1 abolished the repression of its expression by miR-30b-3p or miR-573. When ADAR1 was overexpressed, the reduced abundance of ARHGAP26 protein mediated by miR-30b-3p or miR-573 was rescued. Importantly, we also found that knocking down ADAR1 elevated RhoA activity, which was consistent with the reduced level of ARHGAP26. Conversely, when ADAR1 was overexpressed, the amount of RhoA-GTP decreased. The similar expression patterns of ARHGAP26 and ADAR1 in human tissue samples further confirmed our findings. Taken together, our results suggest that ADAR1 regulates the expression of ARHGAP26 through A-to-I RNA editing by disrupting the binding of miR-30b-3p and miR-573 within the 3' UTR of ARHGAP26. This study provides a novel insight into the mechanism by which ADAR1 and its RNA editing function regulate microRNA-mediated modulation of target genes.