Retracted: In vivo and in vitro effects of microRNA-221 on hepatocellular carcinoma development and progression through the JAK–STAT3 signaling pathway by targeting SOCS3

Hepatocellular carcinoma (HCC), as the third leading cancer-caused deaths, prevails with high mortality, and affects more than half a million individuals per year worldwide. A former study revealed that microRNA-221 (miR-221) was involved in cell proliferation of liver cancer and HCC development. The current study aims to evaluate whether miR-221 targeting SOCS3 affects HCC through JAK–STAT3 signaling pathway. A series of miR-221 mimic, miR-221 inhibitor, siRNA against SOCS3, and SOCS3 plasmids were introduced to SMMC7721 cells with the highest miR-221 expression assessed. The expression of JAK–STAT3 signaling pathway–related genes and proteins was determined by Western blot analysis. Cell apoptosis, viability, migration, and invasion were evaluated by means of flow cytometry, 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide, and transwell assays, respectively. HCC xenograft in nude mice was performed to measure HCC tumor growth. miR-221 was found to be highly expressed but SOCS3 was poorly expressed in HCC tissues. miR-221 expression was correlated with lymph node metastasis (LNM) and tumor node metastasis (TNM) of HCC, and SOCS3 expression was correlated with LNM, differentiation and TNM of HCC. SOCS3 is a target gene of miR-221. MiR-221 mimic or si-SOCS3 exposure was found to induce cell viability, migration, and invasion, and reduce apoptosis. MiR-221 inhibitor was observed to have inhibitory effects on HCC cell proliferation, migration, and invasion. Moreover, the expression of JAK–STAT3 signaling pathway was suppressed by miR-221 inhibitor. Downregulated miR-221 expression could promote its target gene SOCS3 to inhibit the proliferation, invasion and migration of HCC cells by repressing JAK–STAT3 signaling pathway.     

Overexpression of microRNA-190 inhibits migration,invasion, epithelial-mesenchymal transition,and angiogenesis through suppression of protein kinase B-extracellular signal-regulated kinase signaling pathway via binding to stanniocalicin 2 in breast cancer

Breast cancer (BC) is known as the most deadly cancer among females, worldwide. Despite the research advances in this regard, effective diagnosis and treatment still have a long way to go. In this study, our stance was to investigate the regulatory mechanism of miR-190 on epithelial-mesenchymal transition (EMT) and angiogenesis via mediation of protein kinase B (AKT)-extracellular signal-regulated kinase (ERK) signaling pathway by targeting stanniocalicin 2 (STC2) in BC. The BC gene chip was retrieved with differentially expressed genes (DEGs) obtained. MDA-MB-231 and T47D cell lines were selected and separately introduced with miR-190 inhibitors, activators, and small interfering RNAs with the intent of exploring the regulatory functions that miR-190 has shown while governing STC2 in BC. The regulatory effect of miR-190 on cell proliferation, migration, invasion, and angiogenesis was evaluated, followed by determination of AKT-ERK signaling pathway-related factors, EMT-related factors, and angiogenesis-related factors. The xenograft tumor of nude mice was also implemented for determining the change of tumor after transfection. The GSE26910 gene chip was obtained with STC2 being selected as the potential DEG. STC2 was the target gene of miR-190. The results showed that cells introduced with the miR-190 activators along with small interfering RNA-STC2 inhibited proliferation, invasion, migration, angiogenesis, as well as EMT. Moreover, the in vivo experiment also went on to confirm that the tumor volume had significantly increased in the nude mice along with an elevated expression of miR-190. Collectively, the findings suggested that overexpression of miR-190 inhibited EMT and angiogenesis by inactivating AKT-ERK signaling pathway via STC2 in BC.     

Retracted: Targeting of SPP1 by microRNA-340 inhibits gastric cancer cell epithelial–mesenchymal transition through inhibition of the PI3K/AKT signaling pathway

Gastric cancer (GC) is a common heterogeneous disease. The critical roles of microRNA-340 (miR-340) in the development and progression of GC were emphasized in accumulating studies. This study aims to examine the regulatory mechanism of miR-340 in GC cellular processes. Initially, microarray technology was used to identify differentially expressed genes and regulatory miRs in GC. After that, the potential role of miR-340 in GC was determined via ectopic expression, depletion, and reporter assay experiments. Expression of secreted phosphoprotein 1 (SPP1), miR-340, phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway, and epithelial–mesenchymal transition (EMT)-related genes was measured. Moreover, to further explore the function of miR-340 in vivo and in vitro, proliferation, apoptosis, migration, invasion, and tumorigenic capacity were evaluated. SPP1 was a target gene of miR-340 which could then mediate the PI3K/AKT signaling pathway by targeting SPP1 in GC. Furthermore, miR-340 levels were reduced and SPP1 was enriched in GC tissues and cells, with the PI3K/AKT signaling pathway being activated. Inhibitory effects of upregulated miR-340 on SPP1 and the PI3K/AKT signaling pathway were confirmed in vivo and in vitro. Overexpression of miR-340 or the silencing of SPP1 inhibited GC cell proliferation, invasion, migration, and EMT process, but promoted apoptosis of GC cells. Typically, targeting of SPP1 by miR-340 may contribute to the inhibition of proliferation, migration, invasion, and EMT of GC cells via suppression of PI3K/AKT signaling pathway.     

Retracted: Upregulation of microRNA-140-3p inhibits epithelial-mesenchymal transition,invasion, and metastasis of hepatocellular carcinoma through inactivation of the MAPK signaling pathway by targeting GRN

Invasion and metastasis in hepatocellular carcinoma (HCC) results in poor prognosis. Human intervention in these pathological processes may benefit the treatment of HCC. The aim of the present study is to elucidate the mechanism of miR-140-3p affecting epithelial-mesenchymal transition (EMT), invasion, and metastasis in HCC. Microarray analysis was performed for differentially expressed genes screening. The target relationship between miR-140-3p and GRN was analyzed. Small interfering RNA (siRNA) against granulin (GRN) was synthesized. EMT markers were detected, and invasion and migration were evaluated in HCC cells introduced with a miR-140-3p inhibitor or mimic, or siRNA against GRN. A mechanistic investigation was conducted for the determination of mitogen-activated protein kinase (MAPK) signaling pathway-related genes and EMT markers (E-cadherin, N-cadherin, and Vimentin). GRN was highlighted as an upregulated gene in HCC. GRN was a target gene of miR-140-3p. Elevation of miR-140-3p or inhibition of GRN restrained the EMT process and suppressed the HCC cell migration and invasion. HCC cells treated with the miR-140-3p mimic or siRNA-GRN exhibited decreased GRN expression and downregulated the expressions of the MAPK signaling pathway-related genes, N-cadherin, and Vimentin but upregulated the expression of E-cadherin. GRN silencing can reverse the activation of the MAPK signaling pathway and induction of EMT mediated by miR-140-3p inhibition. Taken together, the results show that miR-140-3p confers suppression of the MAPK signaling pathway by targeting GRN, thus inhibiting EMT, invasion, and metastasis in HCC.     

Upregulation of microRNA-141 suppresses epithelial-mesenchymal transition and lymph node metastasis in laryngeal cancer through HOXC6-dependent TGF-β signaling pathway

Laryngeal cancer is one of the most malignant cancers among the head and neck malignant tumors. Abnormal expression of microRNAs (miRNAs) contributes to cancer development through regulating proliferation and apoptosis of cancer cells. In this study, we aim to explore the roles of microRNA-141 (miR-141), Homeobox C6 (HOXC6) and TGF-β signaling pathway in epithelial-mesenchymal transition (EMT) and lymph node metastasis in laryngeal cancer. Initially, we identified differentially expressed genes in laryngeal cancer, among which HOXC6 was identified. Then the target miRNA of HOXC6 was predicted and verified. Next, expression of miR-141, HOXC6, TGF-β1, Smad3, Vimentin and Snail in cancer tissues was detected. Then, AMC-HN-8 cells were transfected with miR-141 mimic, miR-141 inhibitor and HOXC6-siRNA to investigate specific role of miR-141, HOXC6 and TGF-β signaling pathway in laryngeal cancer in vivo and in vitro. Our results showed that HOXC6 was a target gene of miR-141, which was downregulated in laryngeal cancer. Besides, overexpression of miR-141 could downregulate HOXC6 and inhibit the TGF-β signaling pathway. Upregulation of miR-141 or silencing of HOXC6 can repress EMT, viability, migration and invasion abilities of laryngeal cancer cells. In addition, upregulation of miR-141 inhibited the tumor growth and lymph node metastasis in vivo. In summary, our findings demonstrated that upregulated miR-141 decreased HOXC6 expression, and inhibited the TGF-β signaling pathway, EMT and lymph node metastasis in laryngeal cancer, which is of clinical significance in the treatment of laryngeal cancer.     

Retracted: 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.     

MicroRNA-216b targets HK2 to potentiate autophagy and apoptosis of breast cancer cells via the mTOR signaling pathway

Patients suffering from breast cancer (BC) still have a poor response to treatments, even though early detection and improved therapy have contributed to a reduced mortality. Recent studies have been inspired on the association between microRNAs (miRs) and therapies of BC. The current study set out to investigate the role of miR-216b in BC, and further analyze the underlining mechanism. Firstly, hexokinase 2 (HK2) and miR-216b were characterized in BC tissues and cells by RT-qPCR and Western blot assay. In addition, the interaction between HK2 and miR-216b was analyzed using dual luciferase reporter assay. BC cells were further transfected with a series of miR-216b mimic or inhibitor, or siRNA targeting HK2, so as to analyze the regulatory mechanism of miR-216b, HK2 and mammalian target of rapamycin (mTOR) signaling pathway, and to further explore their regulation in BC cellular behaviors. The results demonstrated that HK2 was highly expressed and miR-216b was poorly expressed in BC cells and tissues. HK2 was also verified as a target of miR-216b with online databases and dual luciferase reporter assay. Functionally, miR-216b was found to be closely associated with BC progression via inactivating mTOR signaling pathway by targeting HK2. Moreover, cell viability, migration and invasion were reduced as a result of miR-216b upregulation or HK2 silencing, while autophagy, cell cycle arrest and apoptosis were induced. Taken together, our findings indicated that miR-216b down-regulates HK2 to inactivate the mTOR signaling pathway, thus inhibiting the progression of BC. Hence, this study highlighted a novel target for BC treatment.     

Retracted: Downregulated microRNA-135a ameliorates rheumatoid arthritis by inactivation of the phosphatidylinositol 3-kinase/AKT signaling pathway via phosphatidylinositol 3-kinase regulatory subunit 2

Synovial fibroblasts (SFs) of rheumatoid arthritis (RA) are phenotypically aggressive, typically progressing into arthritic cartilage degradation. Throughout our study, we made explorations into the effects of microRNA-135a (miR-135a) on the SFs involved in RA by mediating the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway via regulation of phosphatidylinositol 3-kinase regulatory subunit 2 (PIK3R2). The expression of PI3K was higher, the expression of PIK3R2 was lower, and AKT was phosphorylated in the RA synovial tissues, relative to the levels found in the normal synovial tissues. We predicted miR-135a to be a candidate miR targeting PIK3R2 using an online website, microRNA.org, which was verified with a dual-luciferase reporter gene assay. Subsequently, high miR-135a expression was observed in RA synovial tissues. To study the effect of the interaction between miR-135a and PIK3R2 in RA, the SFs isolated from RA samples were cultured and transfected with mimic, inhibitor, and small interfering RNA. The proliferation, invasion, and apoptosis of the SFs were detected after the transfection. The cells transfected with miR-135a inhibitor showed inhibited cell proliferation, migration, and invasion, while also displaying promoted cell apoptosis, G0/G1 cell ratio, and decreased S cell ratio, through upregulation of PIK3R2 and inactivation of the PI3K/AKT signaling pathway. These findings provided evidence that downregulation of miR-135a inhibits proliferation, migration, and invasion and promotes apoptosis of SFs in RA by upregulating the PIK3R2 coupled with inactivating the PI3K/AKT signaling pathway. The downregulation of miR-135a might be a potential target in the treatment of RA.     

MicroRNA-329 upregulation impairs the HMGB2/β-catenin pathway and regulates cell biological behaviors in melanoma

Melanoma is responsible for the majority of deaths caused by skin cancer. Antitumor activity of microRNA-329 (miR-329) has been seen in several human cancers. In this study, we identify whether miR-329 serves as a candidate regulator in melanoma. Melanoma-related differentially expressed genes were screened with its potential molecular mechanism predicted. Melanoma tissues and pigmented nevus tissues were collected, where the levels of miR-329 and high-mobility group box 2 (HMGB2) were determined. To characterize the regulatory role of miR-329 on HMGB2 and the β-catenin pathway in melanoma cell activities, miR-329 mimics, miR-329 inhibitors, and siRNA-HMGB2 were transfected into melanoma cells. Cell viability, migration, invasion, cell cycle, and apoptosis were assessed. miR-329 was predicted to influence melanoma by targeting HMGB2 via the β-catenin pathway. High level of HMGB2 and low miR-329 expression were observed in melanoma tissues. HMGB2 was targeted and negatively regulated by miR-329. In melanoma cells transfected with miR-329 mimics or siRNA-HMGB2, cell proliferation, migration, and invasion were impeded, yet cell cycle arrest and apoptosis were promoted, corresponding to decreased levels of β-catenin, cyclin D1, and vimentin and increased levels of GSK3β and E-cadherin. Collectively, our results show that miR-329 can suppress the melanoma progression by downregulating HMGB2 via the β-catenin pathway.     

Inhibitory role of miR-203 in the angiogenesis of mice with pathological retinal neovascularization disease through downregulation of SNAI2

BackgroundPathological retinal neovascularization is a disease characterized by abnormal angiogenesis in retina that is a major cause of blindness in humans. Previous reports have highlighted the involvement of microRNAs (miRNAs) in retinal angiogenesis. Therefore, we aimed at exploring the mechanism underlying miR-203 regulating the progression of pathological retinal neovascularization.MethodsInitially, the mouse model of pathological retinal neovascularization disease was established and the hypoxia-induced human retinal microvascular endothelial cells (HRMECs) were generated. Then, miR-203 and SNAI2 expression in HRMECs and retinal tissues was examined. Subsequently, the effects of miR-203 and SNAI2 on viability, migration, apoptosis and angiogenesis of HRMECs were investigated, with the expression of Bax, Ki-67, MMP-2, MMP-9, VEGF and CD34 measured. Finally, the regulation of miR-203 or SNAI2 on GSK-3β/β-catenin pathway was determined through examining the levels of phosphorylated p-GSK-3β and β-catenin.ResultsPoorly expressed miR-203 and highly expressed SNAI2 were found in HRMECs and retinal tissues of pathological retinal neovascularization. Importantly, overexpressed miR-203 or silencing SNAI2 inhibited viability, migration and angiogenesis but promoted apoptosis of HRMECs, evidenced by elevated Bax expression but reduced expression of Ki-67, MMP-2, MMP-9, VEGF and CD34. Moreover, overexpression of miR-203 was found to repress the GSK-3β/β-catenin pathway by downregulating SNAI2.ConclusionCollectively, this study demonstrated that overexpression of miR-203 suppressed the angiogenesis in mice with pathological retinal neovascularization disease via the inactivation of GSK-3β/β-catenin pathway by inhibiting SNAI2, which provided a novel therapeutic insight for pathological retinal neovascularization disease.     

MicroRNA-10a promotes epithelial-to-mesenchymal transition and stemness maintenance of pancreatic cancer stem cells via upregulating the Hippo signaling pathway through WWC2 inhibition

MicroRNAs (miRNAs)-mediated cancer stem cells (CSCs) have drawn wide attention. This study aimed to probe the role of miR-10a in epithelial–mesenchymal transition (EMT) and stemness maintenance of pancreatic CSCs (PCSCs). Differentially expressed miRs and genes in pancreatic cancer (PC) were predicted via an online database, and the miR-10a and WW and C2 domain containing 2 (WWC2) expression were identified via a comparative study in PC and pancreatitis tissues. PCNCs were isolated and identified, and then the functional roles of miR-10a and WWC2 in proliferation, invasion, migration, self-renewal, colony formation abilities, EMT, and stemness maintenance of PCNCs were determined. The effects of miR-10a on tumor growth in vivo were studied by performing a xenograft tumor in nude mice. Consequently, miR-10a was highly expressed while WWC2 was lowly expressed in PC tissues. miR-10a could target WWC2 expression. miR-10a inhibition reduced EMT and stemness maintenance of PCSCs via enhancing WWC2 expression. The in vitro results were reproduced in in vivo studies. miR-10a promoted EMT and stemness maintenance of PCSCs via activating the Hippo signaling pathway. Our study provided evidence that miR-10a inhibition reduced EMT and stemness maintenance of PCSCs via upregulating WWC2 expression and inhibiting the Hippo signaling pathway.     

Retracted: Effects of microRNA-494 on proliferation,migration, invasion,and apoptosis of medulloblastoma cells by mediating c-myc through the p38 MAPK signaling pathway

Medulloblastoma (MB) is the most prevalent brain tumor that occurs during childhood and originates from cerebellar granule cell precursors. Based on recent studies, the differential expression of several microRNAs is involved in MB, while the role of microRNA-494 (miR-494) in MB remains unclear. Therefore, we conducted this study to investigate the regulative role of miR-494 in MB cells via the p38 mitogen-activated protein kinase (MAPK) signaling pathway by mediating c-myc. In the current study, MB cells were collected and transfected with miR-494 mimic, miR-494 inhibitor, siRNA- c-myc, and miR-494 inhibitor + siRNA-c-myc. The expressions of miR-494, c-myc, p38 MAPK, B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), interleukin-6 (IL-6), metadherin (MTDH), phosphatase and tensin homolog (PTEN) and survivin were determined. Cell proliferation, cell-cycle distribution, apoptosis, migration, and invasion were evaluated. The results revealed that there was a poor expression of miR-494 and high expression of c-myc in MB tissues. C-myc was determined as the target gene of miR-494. In response to miR-494 mimic, MB cells were found to have increased Bax and PTEN expressions, as well as cell number in G1 phase and cell apoptosis and decreased c-myc, p38 MAPK, Bcl-2, MTDH, IL-6, and survivin expression and cell number count in the S phase, cell proliferation, migration, and invasion. In conclusion, the results demonstrated that the upregulation of miR-494 results in the suppression of cell proliferation, migration, and invasion, while it promotes apoptosis of MB cells through the negative mediation of c-myc, which in turn inactivates the p38 MAPK pathway.     

Downregulation of microRNA-205 inhibits cell invasion and angiogenesis of cervical cancer through TSLC1-mediated Akt signaling pathway

Cervical cancer (CC) is a common gynecological cancer and a leading cause of cancer-related deaths in women globally. Therefore, this study explores the action of microRNA-205 (miR-205) in the invasion, migration, and angiogenesis of CC through binding to tumor suppressor lung cancer 1 (TSLC1). Initially, the microarray analysis was used to select the candidate gene and the regulatory microRNA. Then, the target relationship between miR-205 and TSLC1 as well as the expression of miR-205, TSLC1, and p-Akt/total Akt in CC cells were determined. Afterwards, CC cell invasion and migration were detected after the treatment of miR-205 mimics/inhibitors and short hairpin RNA against TSLC1. After coculture of cancer cells and vascular endothelial cells, cell proliferation, tube formation, and microvessel density (MVD) were detected to determine the roles of miR-205 in angiogenesis. Finally, tumor growth in nude mice was measured in vivo. TSLC1 was determined as the candidate gene, which was found to be targeted and negatively regulated by miR-205. Then, downregulated miR-205 or forced TSLC1 expression inhibited invasion, migration, and angiogenesis in CC, corresponding to suppressed cell proliferation, tube formation, and expression of IL-8, VEGF, and bFGF, as well as the inhibited activation of the Akt signaling pathway. Furthermore, downregulation of miR-205 was found to exert an inhibitory role in tumor formation and MVD by elevating TSLC1 in CC in vivo. This study demonstrated that downregulated miR-205 inhibited cell invasion, migration, and angiogenesis in CC by inactivating the Akt signaling pathway via TSLC1 upregulation.     

MicroRNA-1271 functions as a potential tumor suppressor in hepatitis B virus–associated hepatocellular carcinoma through the AMPK signaling pathway by binding to CCNA1

Hepatocellular carcinoma (HCC) is mainly associated with hepatitis B virus (HBV) infection and characterized by metastasizing and infiltrating adjacent and distant tissues. Notably, microRNA-1271 (miR-1271) is a tumor suppressor in various cancers. Therefore, we evaluate the ability of miR-1271 to influence cell proliferation, migration, invasion, and apoptosis in HBV-associated HCC through the Adenosine monophosphate–activated protein kinase (AMPK) signaling pathway via targeting CCNA1. HBV-associated HCC and adjacent normal tissues were collected to identify the expression of miR-1271 and CCNA1. To verify the relationship between miR-1271 and CCNA1, we used bioinformatics prediction and the dual-luciferase reporter gene assay. The effects of miR-1271 on HBV-associated HCC cell behaviors were investigated by treatment of the miR-1271 mimic, the miR-1271 inhibitor, or small interfering RNA against CCNA1. The HBV-DNA quantitative assay, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromid assay, scratch test, transwell assay, and flow cytometry were used to detect HBV-DNA replication, cell proliferation, invasion, migration, and apoptosis. MiR-1271 showed a low expression, whereas CCNA1 showed a high expression in HBV-associated HCC tissues. We identified that miR-1271 targeted and negatively regulated CCNA1. Upregulated miR-1271 and downregulated CCNA1 inhibited the HBV-associated HCC cell HBV-DNA replication, proliferation, migration, and invasion, while accelerating apoptosis by activating the AMPK signaling pathway. MiR-1271 promotes the activation of the AMPK signaling pathway by binding to CCNA1, whereby miR-1271 suppresses HBV-associated HCC progression. This study points to a potential therapeutic approach of downregulation of miR-1271 in HBV-associated HCC treatment.