MicroRNA-543 promotes cell invasion and impedes apoptosis in pituitary adenoma via activating the Wnt/ß-catenin pathway by negative regulation of Smad7.

Pituitary adenomas (PA) are commonly occurring benign neoplasms. Identification of molecular pathway resulting in pituitary tumorigenesis remains challenges in endocrine oncology. The present study was conducted with aim of investigating the role of microRNA-543 (miR-543) in PA development. Up-regulated miR-543 and downregulated Smad7 were observed in PA tissues. Afterwards, the specific mechanism of miR-543 and Smad7 in PA were determined with the use of ectopic expression, depletion and reporter assay experiments. Smad7 was confirmed as a target gene of miR-543. HP75 cells treated with overexpressed miR-543 exhibited increased cell proliferation, migration and invasion, while decreased cell apoptosis as well as expression of Cleaved caspase-3 and Cleaved caspase-8 were observed. Suppression of miR-543 contributed to an opposite trend to the above findings. Based on the findings, the inhibition of miR-543 was found to play a tumor suppressive role in PA through the down-regulation of Wnt/ß-catenin pathway by negatively regulating Smad7.

MicroRNA-543 functions as an osteogenesis promoter in human periodontal ligament-derived stem cells by inhibiting transducer of ERBB2, 2.

BACKGROUND AND OBJECTIVE: Previous research has indicated that altered expression of microRNAs (miRNAs) is in connection with osteogenesis of human periodontal ligament-derived stem cells (hPDLSCs). We investigated the mechanisms by which miR-543 promotes osteogenic differentiation of hPDLSCs. MATERIAL AND METHODS: First, the expression of miR-543 in hPDLSCs cultured with or without an osteogenic inductive cocktail was explored. Then, the function of miR-543 during osteogenesis of hPDLSCs was investigated by overexpressing and inhibiting miR-543. Next, 3 databases were used to predict target genes of miR-543 and a luciferase report was used to validate the direct regulation of miR-543 on the target gene. Further, a rescue experiment using co-transfection of miR-543 mimic and target mimic was performed to evaluate whether overexpressing the target gene could partly rescue the efficiency of overexpressing miR-543 on osteogenesis in hPDLSCs. RESULTS: miR-543 was upregulated during osteogenic differentiation of hPDLSCs. Functional experiments showed that overexpressing miR-543 could enhance osteogenesis, while inhibiting miR-543 resulted in reduced formation of mineralized nodules. The transducer of ERBB2, 2 (TOB2) was identified as a target gene of miR-543 and luciferase report revealed that miR-543 interacts directly with the 3'-untranslated repeat sequence of TOB2 mRNA. Overexpression of miR-543 inhibited the expression of TOB2 in both mRNA and protein levels while inhibiting miR-543 increased. Furthermore, the rescue experiment confirmed the promotional role of miR-543 TOB2 expression could be abrogated by overexpressing TOB2, which also had the effect of reducing osteogenic differentiation. CONCLUSION: Our research confirmed that miR-543 is a promoter of osteogenesis in hPDLSCs, acting by inhibiting its target gene TOB2, which suggests that miR-543 may be a potential therapy for bone loss in periodontitis.

MicroRNA-543 acts as a prognostic marker and promotes the cell proliferation in cervical cancer by BRCA1-interacting protein 1.

Human cervical cancer is one of the most common malignancies worldwide. Recent studies have focused on microRNAs that play crucial roles in cancer development and progression of cervical cancer. In this study, we aimed to analyse the biological function of microRNA-543 in cervical cancer. Samples of human cervical cancer and matched adjacent normal cervical tissues were collected, and expression level of microRNA-543 and the clinical characteristics of cervical cancer were investigated. We found that microRNA-543 expression was significantly elevated in cervical cancer and its aberrant expression levels were positively correlated with tumour size ( p = 0.0315), differentiation ( p = 0.0134), clinical stage ( p = 0.0315) and overall ( p = 0.0426) and disease-free survival ( p = 0.0396) of cervical cancer. Overexpression of microRNA-543 in cancer-derived HeLa and SiHa facilitated cell growth and suppressed cell apoptosis, while down-regulation of microRNA-543 exerted a reverse effect on cell growth and apoptosis. In addition, we demonstrated that BRCA1-interacting protein 1 was directly regulated by microRNA-543 and the restoration of BRCA1-interacting protein 1 expression reversed the effects of microRNA-543 on cell proliferation. Taken together, these findings collectively demonstrate that microRNA-543 exerts its oncogene function by directly targeting BRCA1-interacting protein 1 in cervical cancer, indicating a potential novel potential prognostic biomarker and therapeutic target for cervical cancer.

MicroRNA-543 controls pancreatic cancer development by LINC00847-microRNA-543-STK31 axis.

Background: Pancreatic cancer (PC) is one of the most malignant cancers of the gastrointestinal tract. However, the study of targeted therapy research in PC is not very thorough. Therefore, targeted molecular markers are needed to aid in the diagnosis and treatment of PC. Methods: In our research, we investigated the biological functions and molecular mechanism of microRNA-543 in PC. Western blotting (WB) and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to analyze the transcription and protein expression of microRNA-543, Serine/threonine kinase 31 (STK31), and LINC00847 in BxPC-3 and PANC-1 cells. Subsequently, Cell Counting Kit-8 (CCK-8), Transwell, colony formation, and flow cytometry (FCM) assays were utilized to evaluate cell growth, migration, invasion, and apoptosis. WB and fluorescence in-situ hybridization (FISH) were used to evaluate the epithelial-mesenchymal transition (EMT) process and subcellular localization. RNA immunoprecipitation (RIP), double luciferase reporter, and RNA-pull down assays were performed to determine the targeting relationship between microRNA-543 and STK31 or microRNA-543 and LINC00847. Results: While microRNA-543 expression was discovered to be low in PC, LINC00847 and STK31 were overexpressed at significant levels. MicroRNA-543 knockdown dramatically increased PC cell growth, invasion, metastasis, and EMT, as well as decreased apoptosis in functional studies. Furthermore, microRNA-543 and STK31 were found to be mutual targets. LINC00847 acted as a molecular sponge for microRNA-543 and a competitive endogenous RNA (ceRNA) for STK31, thereby increasing STK-31 transcription. Conclusions: Our results suggest that microRNA-543, through the LINC00847/microRNA-543/STK31 axis, plays a role in the development of PC as a tumor suppressor. As a result, microRNA-543 may prove to be an effective diagnostic and therapeutic target for PC.

MicroRNA-543 inhibits the proliferation, migration, invasion, and epithelial-mesenchymal transition of triple-negative breast cancer cells via down-regulation of ACTL6A gene.

PURPOSE: To investigate the effect of microRNA-543 (miR-543) on the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of triple-negative breast cancer (TNBC) cells, and the associated mechanism. METHODS: Human breast cancer cells (MDA-MB-231, HCC1937, and MCF-7, ZR-75-1) and normal human breast epithelial cell line (MCF10A) were transfected with miR-543 mimics or inhibitor using lipofectamine 2000. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting were used to determine the mRNA and protein expression levels of miR-543, actin-like protein 6A (ACTL6A), vimentin, Snail, and E-cadherin in breast cancer cells/tissue. Cell counting kit-8 (CCK-8), wound-healing, and Transwell assays were used to measure the effect of miR-543 on TNBC cell proliferation, invasion, and migration. Overall survival was determined using data from Gene Expression Omnibus (GEO) and Cancer Genome Atlas (TCGA) databases. Bioinformatics analysis and luciferase reporter gene assay were used to determine the regulatory effect of miR-543 on ACTL6A. RESULTS: The level of expression of miR-543 was significantly lower in breast cancer cells/tissue than in normal human breast epithelial cell/tissue (p < 0.05). MicroRNA-543 expression level was significantly reduced in TNBC cells/tissue, relative to the other breast cancer cells/normal breast tissue (p < 0.05). MicroRNA-543 significantly suppressed tumor growth and the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of TNBC cells, in mouse xenograft model (p < 0.05). CONCLUSIONS: miR-543 influences the biological behavior of TNBC cells by directly targeting ACTL6A gene. miR-543 could serve as a novel diagnostic and therapeutic target for TNBC.

Identification of the tumor­suppressive role of circular RNA­FOXO3 in colorectal cancer via regulation of miR­543/LATS1 axis.

Colorectal cancer (CRC) is a common malignancy with significant prevalence and mortality rates. Circular RNA FOXO3 (circ­FOXO3; hsa_circ_0006404) has been reported to be involved in cancer regulation; however, its role in CRC is yet to be fully elucidated. Therefore, the aim of the present study was to investigate the effect of circ­FOXO3 on CRC progression and identify its underlying mechanism. In the present study, the expression of circ­FOXO3 was investigated in CRC tissues and cells via reverse transcription­quantitative PCR. A Cell Counting Kit­8 and colony formation assays were used to assess cell proliferation. The cell migratory and invasive abilities were detected using the Transwell migration and invasion assays. The luciferase assay and RNA pull­down assay were conducted to verify the relationship of circ­FOXO3, microRNA (miR)­543 and Large tumor suppressor kinase 1 (LATS1). The results demonstrated that circ­FOXO3 expression was downregulated in CRC tissues and cells, and was associated with poor overall survival of patients with CRC. Moreover, circ­FOXO3 was associated with tumor size, distant metastasis, differentiation, lymph node metastasis and TMN stages of patients with CRC. circ­FOXO3 overexpression suppressed CRC cell proliferation, migration and invasion. Luciferase assay and RNA pull­down assay results indicated that circ­FOXO3 functioned as a sponge for miR­543. In addition, circ­FOXO3 increased the expression of LATS1 via sponging miR­543, thus inhibiting CRC cell aggressive features. Collectively, the present results suggested that circ­FOXO3 inhibited CRC metastasis and progression via elevated LATS1 expression by sponging miR­543. Therefore, circ­FOXO3 may be a promising target for CRC therapy.

Circular RNA FOXO3 accelerates glycolysis and improves cisplatin sensitivity in lung cancer cells via the miR-543/Foxo3 axis.

Non-small cell lung cancer (NSCLC) is the most common cause of cancer-associated mortality worldwide. Our previous study revealed that circular RNA (circRNA)-FOXO3 is highly expressed in lung cancer and inhibits cell proliferation. However, to the best of our knowledge, at present, no study has focused on the specific mechanism of circRNA-FOXO3 in drug resistance. Therefore, the present study aimed to provide novel perspectives on the role of circRNA-FOXO3 in cisplatin (DDP) resistance in NSCLC. A Cell Counting Kit-8 assay was used to determine the viability of cells overexpressed with circRNA-FOXO3 and under DDP treatment. Glycolysis was analyzed by measuring glucose consumption and lactate production. The interaction of circRNA-FOXO3, microRNA 543 (miR-543) and Foxo3 was confirmed using a dual-luciferase reporter assay. It was revealed that circRNA-FOXO3 improved cell sensitivity to DDP and repressed glycolysis in DDP-sensitive and DDP-resistant NSCLC cells. Bioinformatics analysis, luciferase reporter assays, quantitative PCR and RNA pull-down assays were employed to verify the binding of circRNA-FOXO3 to miR-543. Functionally, inhibition of miR-543 could sensitize NSCLC cells to DDP, and overexpression of miR-543 at least partially abolished the circRNA-FOXO3-induced decrease in chemoresistance. Furthermore, it was revealed that Foxo3 was a direct target of miR-543. Notably, the inhibitory action of miR-543 silencing on DDP resistance and glycolysis was reversed by overexpression of Foxo3 in DDP-sensitive and DDP-resistant NSCLC cells. In conclusion, the present study demonstrated that circRNA-FOXO3 promoted DDP sensitivity in NSCLC cells by regulating the miR-543/Foxo3 axis-mediated glycolysis balance. The present findings may provide novel perspectives for the treatment of patients with NSCLC resistant to DDP.

miR­217 and miR­543 downregulation mitigates inflammatory response and myocardial injury in children with viral myocarditis by regulating the SIRT1/AMPK/NF­κB signaling pathway.

The aim of the present study was to investigate the expression levels and roles of microRNA (miR)­217 and miR­543 in viral myocarditis, and to examine their underlying mechanisms. Coxsackievirus B3 (CVB3) was used to establish in vivo and in vitro models of viral myocarditis. The levels of miR­217 and miR­543 were detected using reverse transcription­quantitative PCR. The association between miR­217 and miR­543 and sirtuin­1 (SIRT1) was predicted and confirmed by TargetScan and dual­luciferase reporter assay. Cell viability was detected using Cell Counting Kit­8 assay, and cell apoptosis was measured by analyzing the expression levels of Bcl­2 and Bax, and by flow cytometry. In addition, the synthesis of various pro­inflammatory factors was determined by ELISA. In addition, superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels were measured in cardiomyocytes following transfection and CVB infection. miR­217 and miR­543 were found to be highly expressed in the peripheral blood of pediatric patients with viral myocarditis, in the peripheral blood and myocardial tissues of viral myocarditis mice and in CVB3­infected cardiomyocytes. SIRT1 was found to be a target of both miR­217 and miR­543, and SIRT1 expression level was downregulated in viral myocarditis. Further analysis indicated that the reduced cell viability, increased cell apoptosis, enhanced synthesis of inflammatory factors, increased MDA content and decreased SOD activity associated with myocarditis were significantly reversed after inhibition of miR­217 or miR­543. Importantly, the present results showed that all the effects of miR­217 and miR­543 inhibition on cardiomyocytes were significantly suppressed following SIRT1 knockdown. Collectively, the present data indicated that miR­217 and miR­543 were significantly upregulated in viral myocarditis, and downregulation of miR­217 and miR­543 attenuated CVB3 infection­induced cardiomyocyte injury by targeting SIRT1. miR­217 and miR­543 may be potential therapeutic targets for developing novel viral myocarditis treatments in the future.

Long Noncoding RNA ST7-AS1 Upregulates TRPM7 Expression by Sponging microRNA-543 to Promote Cervical Cancer Progression.

PURPOSE: ST7 antisense RNA 1 (ST7-AS1) is a long noncoding RNA that affects the progression of gastric cancer and laryngeal squamous cell carcinoma. Herein, ST7-AS1 expression was detected in cervical cancer tissues and cell lines. In addition, its biological roles in inducing the aggressive phenotype of cervical cancer and its associated mechanisms of action were illustrated. PATIENTS AND METHODS: ST7-AS1 expression in cervical cancer tissues and cell lines was detected using quantitative real-time polymerase chain reaction (qRT-PCR). Malignancy was determined using Cell Counting Kit-8 assay, flow cytometry, transwell migration and invasion assays, and xenograft experiments. Bioinformatics analysis was performed to predict the interaction between ST7-AS1 and microRNA-543 (miR-543). Luciferase reporter assay, RNA immunoprecipitation assay, Western blotting, qRT-PCR, and rescue experiments were performed to further identify the interactions among ST7-AS1, miR-543, and transient receptor potential melastatin 7 (TRPM7). RESULTS: ST7-AS1 was upregulated in cervical cancer tissues and cell lines. ST7-AS1 overexpression was correlated with a high International Federation of Gynecology and Obstetrics stage, frequent lymph node metastasis, deep cervical invasion, and short overall survival in patients with cervical cancer. ST7-AS1 inhibition hindered cervical cancer cell proliferation, migration, and invasion; ST7-AS1 downregulation resulted in marked cell apoptosis. Additionally, ST7-AS1 deficiency restricted cervical tumor growth in vivo. Mechanistically, ST7-AS1 functioned as competing endogenous RNA to increase TRPM7 expression by sponging miR-543. Intriguingly, rescue experiments revealed that miR-543 downregulation or TRPM7 overexpression abrogated the inhibitory actions of ST7-AS1 knockdown in the aggressive phenotype of cervical cancer cells. CONCLUSION: The newly identified ST7-AS1/miR-543/TRPM7 axis promoted the oncogenicity of cervical cancer cells both in vitro and in vivo. Our study highlighted the importance of this novel axis in cervical cancer progression, suggesting that this pathway can serve as a promising therapeutic target for cervical cancer.

Knockdown of long non-coding RNA PVT1 induces apoptosis of fibroblast-like synoviocytes through modulating miR-543-dependent SCUBE2 in rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA), a kind of autoimmune disorder, is featured by many physical symptoms and proliferation of fibroblast-like synoviocytes (FLSs). The relevance of long non-coding RNAs (lncRNAs) in the progression of RA has been probed. Hence, the goal of this report was to investigate the action of plasmacytoma variant translocation 1 (PVT1), a lncRNA, in FLSs and the basic mechanism. METHODS: Initially, RA rats were developed to evaluate the expression of PVT1, microRNA-543 (miR-543), and signal peptide-CUB-EGF-like containing protein 2 (SCUBE2) in synovial tissues. Enhancement or loss of PVT1 or miR-543 was achieved to explore their effects on proliferation, cell cycle, and apoptosis of FLSs. The interaction between PVT1 and miR-543 and between miR-543 and its putative target SCUBE2 was examined to elucidate the correlations. Finally, the protein expression of proliferation- and apoptosis-associated genes were assessed by western blot assays. RESULTS: PVT1 was overexpressed in synovial tissues from RA patients through microarray expression profiles. The PVT1 and SCUBE2 expression was boosted, and miR-543 was reduced in synovial tissues of rats with RA. PVT1 specifically bound to miR-543, and miR-543 negatively regulated SCUBE2 expression. Overexpression of PVT1 or silencing of miR-543 enhanced SCUBE2 expression, thereby promoting proliferation and interleukin-1ß (IL-1ß) secretion, while inhibiting apoptosis rate of FLSs. Conversely, si-SCUBE2 reversed the role of miR-543 inhibitor. CONCLUSION: The key findings support that PVT1 knockdown has the potency to hinder RA progression by inhibiting SCUBE2 expression to sponge miR-543.

Down-regulation of miR-543 expression increases the sensitivity of colorectal cancer cells to 5-Fluorouracil through the PTEN/PI3K/AKT pathway.

Resistance to chemotherapy is one of main obstacles in the treatment of colorectal cancer (CRC). However, the mechanisms are still unclear, and the treatment options are still limited. miR-543 has been indicated to act as an oncogene in some cancers, but its function in regulating chemoresistance has not been considered in CRC cells. This study investigated whether the down-regulation of miR-543 expression enhanced 5-fluorouracil (5-FU)-induced apoptosis in HCT8/FU colon cancer cells. In our study, qRT-PCR revealed that miR-543 expression was up-regulated in the HCT8/FU colon cancer cell line compared with that of HCT8 colon cancer cell line. An miR-543 inhibitor or mimic was transfected, followed by MTT assay to detect 5-FU sensitivity in HCT8 and HCT8/FU cell lines, which showed that IC50 of 5-FU was positively correlated with miR-543 expression. Further studies showed that miR-543 enhanced drug resistance by down-regulating the expression of phosphatase and tensin homolog (PTEN), which negatively regulates protein kinase B (AKT) activation. Additionally, an elevated expression of PTEN reversed the chemoresistance of miR-543-overexpressing HCT8 cells to 5-FU. These results indicate that miR-543 might be a target to increase the sensitivity of CRC cells to 5-FU through the PTEN/PI3K/AKT pathway.

MicroRNA-543 suppresses liver cancer growth and induces apoptosis via the JAK2/STAT3 signaling pathway.

The aim of the present study was to investigate the function of microRNA-543 on liver cancer cell proliferation and apoptosis, and also to identify whether the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway was a direct target of microRNA-543. When compared with paracarcinoma tissue, microRNA-543 expression in tissue samples from patients with liver cancer was identified to be decreased. Furthermore, overall survival of patients with high microRNA-543 expression was increased compared with patients with low microRNA-543 expression. Inhibition of microRNA-543 expression increased cell proliferation and decreased apoptosis of liver cancer cells. It also activated the protein expression of phosphorylated JAK2, phosphorylated STAT3, c-Myc and B-cell lymphoma 2 (Bcl-2) in liver cancer cells. However, activation of microRNA-543 expression in turn decreased cell proliferation and increased apoptosis of liver cancer cells. The results of the present study highlight the pivotal function of microRNA-543 as an inhibitor in liver cancer cell proliferation by observing JAK2/STAT3/c-Myc/Bcl-2 in liver cancer.

MicroRNA 543 suppresses breast cancer cell proliferation, blocks cell cycle and induces cell apoptosis via direct targeting of ERK/MAPK.

BACKGROUND: Breast cancer affects millions of people with a high mortality rate throughout the world; microRNA 543 (miR-543) has been reported to suppress progression in some kinds of cancers, but has not been reported in breast cancer. Thus, the purpose of this study is to investigate the function of miR-543 in breast cancer cells. METHODS: Two cell lines, MCF-7 and MDA-MB-231, were selected to be the research objects; the miR-543 overexpression and knockdown models were established in the study by transforming miR-543 mimics and miR-543 inhibitor. Real-time polymerase chain reaction, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, Western blot, clone formation and cell flow cytometer assay were used to test the miR-543's function. Dual-luciferase assay was used for the detection of miR-543 and ERK2 targeting relationship. RESULTS: The results showed that the cell proliferation and cell cycle were inhibited, and the capability of cell apoptosis was upregulated when miR-543 was overexpressed; we found that there was a target relationship between ERK2 and miR-543. Furthermore, downstream factors of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase-2 (ERK2) pathway, including RSK2 and MSK1, were decreased in miR-543 overexpression model. CONCLUSION: This study provides series evidences to support that breast cancer progression was inhibited by miR-543 via direct targeting of ERK2 in MAPK/ERK signal pathway, which may provide a molecular basis for better treatment for patients.