Low expression of miR-381 is a favorite prognosis factor and enhances the chemosensitivity of osteosarcoma

18β-glycyrrhetinic acid promotes gastric cancer cell autophagy and inhibits proliferation by regulating miR-328-3p/signal transducer and activator of transcription 3

BACKGROUND

Gastric cancer (GC) is one of the most common cancer types worldwide, and its prevention and treatment methods have garnered much attention. As the active ingredient of licorice, 18β-glycyrrhetinic acid (18β-GRA) has a variety of pharmacological effects. The aim of this study was to explore the effective target of 18β-GRA in the treatment of GC, in order to provide effective ideas for the clinical prevention and treatment of GC.

AIM

To investigate the mechanism of 18β-GRA in inhibiting cell proliferation and promoting autophagy flux in GC cells.

METHODS

Whole transcriptomic analyses were used to analyze and screen differentially expressed microRNAs (miRNAs) in GC cells after 18β-GRA intervention. Lentivirus-transfected GC cells and the Cell Counting Kit-8 were used to detect cell proliferation ability, cell colony formation ability was detected by the clone formation assay, and flow cytometry was used to detect the cell cycle and apoptosis. A nude mouse transplantation tumor model of GC cells was constructed to verify the effect of miR-328-3p overexpression on the tumorigenicity of GC cells. Tumor tissue morphology was observed by hematoxylin and eosin staining, and microtubule-associated protein light chain 3 (LC3) expression was detected by immunohistochemistry. TransmiR, STRING, and miRWalk databases were used to predict the relationship between miR-328-3p and signal transducer and activator of transcription 3 (STAT3)-related information. Expression of STAT3 mRNA and miR-328-3p was detected by quantitative polymerase chain reaction (qPCR) and the expression levels of STAT3, phosphorylated STAT3 (p-STAT3), and LC3 were detected by western blot analysis. The targeted relationship between miR-328-3p and STAT3 was detected using the dual-luciferase reporter gene system. AGS cells were infected with monomeric red fluorescent protein-green fluorescent protein-LC3 adenovirus double label. LC3 was labeled and autophagy flow was observed under a confocal laser microscope.

RESULTS

The expression of miR-328-3p was significantly upregulated after 18β-GRA intervention in AGS cells (P = 4.51E-06). Overexpression of miR-328-3p inhibited GC cell proliferation and colony formation ability, arrested the cell cycle in the G0/G1 phase, promoted cell apoptosis, and inhibited the growth of subcutaneous tumors in BALB/c nude mice (P < 0.01). No obvious necrosis was observed in the tumor tissue in the negative control group (no drug intervention or lentivirus transfection) and vector group (the blank vector for lentivirus transfection), and more cells were loose and necrotic in the miR-328-3p group. Bioinformatics tools predicted that miR-328-3p has a targeting relationship with STAT3, and STAT3 was closely related to autophagy markers such as p62. After overexpressing miR-328-3p, the expression level of STAT3 mRNA was significantly decreased (P < 0.01) and p-STAT3 was downregulated (P < 0.05). The dual-luciferase reporter gene assay showed that the luciferase activity of miR-328-3p and STAT3 3' untranslated regions of the wild-type reporter vector group was significantly decreased (P < 0.001). Overexpressed miR-328-3p combined with bafilomycin A1 (Baf A1) was used to detect the expression of LC3 II. Compared with the vector group, the expression level of LC3 II in the overexpressed miR-328-3p group was downregulated (P < 0.05), and compared with the Baf A1 group, the expression level of LC3 II in the overexpressed miR-328-3p + Baf A1 group was upregulated (P < 0.01). The expression of LC3 II was detected after intervention of 18β-GRA in GC cells, and the results were consistent with the results of miR-328-3p overexpression (P < 0.05). Additional studies showed that 18β-GRA promoted autophagy flow by promoting autophagosome synthesis (P < 0.001). qPCR showed that the expression of STAT3 mRNA was downregulated after drug intervention (P < 0.05). Western blot analysis showed that the expression levels of STAT3 and p-STAT3 were significantly downregulated after drug intervention (P < 0.05).

CONCLUSION

18β-GRA promotes the synthesis of autophagosomes and inhibits GC cell proliferation by regulating the miR-328-3p/STAT3 signaling pathway.

A five ferroptosis-related genes risk score for prognostic prediction of osteosarcoma

BACKGROUND

Osteosarcoma (OS) is the most common bone cancer in adolescents, and has a high propensity to metastasize. Ferroptosis is a unique modality of cell death, driving the metastasis of cancer cells. Identifying ferroptosis-related genes (FRGs) as prognostic factors will be critical to predict the outcomes of OS. This study aimed to explore the prognostic value of FRGs in OS and build a prognostic model to indirectly improve OS patients' outcomes.

METHODS

OS data were downloaded from the TARGET database and 2 Gene Expression Omnibus datasets. Univariate Cox regression was conducted to assess FRGs. A risk score model basing on 5 FRGs was constructed via LASSO-Cox regression. Multivariate Cox regression analysis was used to determine the independent prognostic factors. The Nomogram model was built using independent prognostic factors. The relationship between the risk score and the immune cell infiltration was estimated by CIBERSORT, and the correlation between the risk score and immune checkpoints was also analyzed.

RESULTS

Based on the prognosis-related FRGs, we built a regression model: Risk score = (-0.01382853 × ACSL4) - (0.05371778 × HMOX1) - (0.02434655 × GPX4) - (0.16432810 × PRNP) - (0.15567120 × ATG7). OS patients with high risk score tended to suffer from poor prognosis, validated in 2 Gene Expression Omnibus datasets. The Nomogram model showed the combination of the risk score and the tumour-node-metastasis stage improved predictive effectiveness. The risk score was also related to immune cell infiltration and immune checkpoint expression.

CONCLUSION

The risk score model based on 5 FRGs was a reliable prognostic predictive indicator for OS patients.

The Roles of Exosomes upon Metallic Ions Stimulation in Bone Regeneration

Metallic ions have been widely investigated and incorporated into bone substitutes for bone regeneration owing to their superior capacity to induce angiogenesis and osteogenesis. Exosomes are key paracrine mediators that play a crucial role in cell-to-cell communication. However, the role of exosomes in metallic ion-induced bone formation and their underlying mechanisms remain unclear. Thus, this review systematically analyzes the effects of metallic ions and metallic ion-incorporated biomaterials on exosome secretion from mesenchymal stem cells (MSCs) and macrophages, as well as the effects of secreted exosomes on inflammation, angiogenesis, and osteogenesis. In addition, possible signaling pathways involved in metallic ion-mediated exosomes, followed by bone regeneration, are discussed. Despite limited investigation, metallic ions have been confirmed to regulate exosome production and function, affecting immune response, angiogenesis, and osteogenesis. Although the underlying mechanism is not yet clear, these insights enrich our understanding of the mechanisms of the metallic ion-induced microenvironment for bone regeneration, benefiting the design of metallic ion-incorporated implants.

Mg2+ -mediated autophagy-dependent polarization of macrophages mediates the osteogenesis of bone marrow stromal stem cells by interfering with macrophage-derived exosomes containing miR-381

Magnesium ion (Mg²⁺ ) has received increased attention due to the roles it plays in promoting osteogenesis and preventing inflammation. This study was designed to investigate the mechanism by which Mg²⁺ influences the osteoblastic differentiation of bone marrow stromal stem cells (BMSCs). The polarization of Mø (macrophages) was measured after treatment with Mg²⁺ . Meanwhile, autophagy in Mø was measured by detecting LC3B expression. Mø-derived exosomes were isolated and cocultured with BMSCs; after which, osteogenic differentiation was evaluated by Alizarin Red staining and detection of alkaline phosphatase (ALP). Our results showed that Mg²⁺ could induce autophagy in macrophages and modulate the M1/M2 polarization of macrophages. Mg²⁺ -mediated macrophages could facilitate the osteogenic differentiation of BMSCs by regulating autophagy, and this facilitation by Mg²⁺ -mediated macrophages was closely related to macrophage-derived exosomes, and especially exosomes containing miR-381. However, miR-381 in macrophages did not influence autophagy or the polarization of Mg²⁺ -mediated macrophages. Furthermore, macrophage-derived exosomes containing miR-381 mainly determined the osteogenic differentiation of BMSCs. Mg²⁺ -mediated macrophages were shown to promote the osteogenic differentiation of BMSCs via autophagy through reducing miR-381 in macrophage-derived exosomes. In conclusion, our results suggest Mg²⁺ -mediated macrophage-derived exosomes containing miR-381 as novel vehicles for promoting the osteogenic differentiation of BMSCs.

Identification and Validation of miRNA-TF-mRNA Regulatory Networks in Uterine Fibroids

Uterine fibroids (UF) are the most common benign gynecologic tumors and lead to heavy menstrual bleeding, severe anemia, abdominal pain, and infertility, which seriously harm a women’s health. Unfortunately, the regulatory mechanisms of UF have not been elucidated. Recent studies have demonstrated that miRNAs play a vital role in the development of uterine fibroids. As a high-throughput technology, microarray is utilized to identify differentially expressed genes (DEGs) and miRNAs (DEMs) between UF and myometrium. We identified 373 candidate DEGs and the top 100 DEMs. Function enrichment analysis showed that candidate DEGs were mainly enriched in biological adhesion, locomotion and cell migration, and collagen-containing extracellular matrix. Subsequently, protein-protein interaction (PPI) networks are constructed to analyze the functional interaction between DEGs and screen hub DEGs. Subsequently, the expression levels of hub DEGs were validated by real-time PCR of clinical UF samples. The DGIdb database was used to select candidate drugs for hub DEGs. Molecular docking was applied to test the affinity between proteins and drugs. Furthermore, target genes for 100 candidate DEMs were predicted by miRwalk3.0. After overlapping with 373 candidate DEGs, 28 differentially expressed target genes (DEGTs) were obtained. A miRNA-mRNA network was constructed to investigate the interactions between miRNA and mRNA. Additionally, two miRNAs (hsa-miR-381-3p and hsa-miR-181b-5p) were identified as hub DEMs and validated through RT-PCR. In order to better elucidate the pathogenesis of UF and the synergistic effect between miRNA and transcription factor (TF), we constructed a miRNA-TF-mRNA regulatory network. Meanwhile, in vitro results suggested that dysregulated hub DEMs were associated with the proliferation, migration, and apoptosis of UF cells. Our findings provided a novel horizon to reveal the internal mechanism and novel targets for the diagnosis and treatment of UF.

MicroRNA-381 in human cancer: Its involvement in tumour biology and clinical applications potential

MicroRNAs (miRNAs) are small non‐coding RNAs that regulate gene expression at the post‐transcriptional level. MiRNAs are involved in the development and progression of a wide range of cancers. Among such cancer‐associated miRNAs, miR‐381 has been a major focus of research. The expression pattern and role of miR‐381 vary among different cancer types. MiR‐381 modulates various cellular behaviours in cancer, including proliferation, apoptosis, cell cycle progression, migration and invasion. MiR‐381 is also involved in angiogenesis and lymphangiogenesis, as well as in the resistance to chemotherapy and radiotherapy. MiR‐381 itself is regulated by several factors, such as long noncoding RNAs, circular RNAs and cytokines. Aberrant expression of miR‐381 in blood samples indicates that it can be used as a diagnostic marker in cancer. Tissue miR‐381 expression may serve as a prognostic factor for the clinicopathological characteristics of cancers and survival of patients. Metformin and icaritin regulate miR‐381 expression and present anticancer properties. This review comprehensively summarizes the effect of miR‐381 on tumour biological behaviours, as well as the clinical application potential of miR‐381 for the treatment of cancer.

Effect of lncRNA XLOC_005950 knockout by CRISPR/Cas9 gene editing on energy metabolism and proliferation in osteosarcoma MG63 cells mediated by hsa-miR-542-3p

Cancer cells use glucose via glycolysis to maintain tumor cell proliferation. However, the effect of long non-coding RNAs (lncRNAs) on glycolysis in osteosarcoma (OS) cells remains unclear. The present study aimed to investigate the involvement of the lncRNA XLOC_005950/hsa-microRNA (miR)-542-3p/phosphofructokinase, muscle (PFKM) axis in the regulation of glucose metabolism, cell proliferation and apoptosis in the progression of OS. lncRNA XLOC_005950, hsa-miR-542-3p and PFKM expression in OS tissues and cells was detected via reverse transcription-quantitative PCR analysis. CRISPR/Cas9 gene editing was used to knockout lncRNA XLOC_005950 expression in MG63 cells. Cell Counting Kit-8 assay, flow cytometry, PFKM activity, and glucose and lactic acid content determination were performed to assess the effects of lncRNA XLOC_005950 knockout and overexpression of hsa-miR-542-3p on the phenotypes of OS cells. The dual-luciferase reporter assay was performed to confirm the targeting associations between lncRNA XLOC_005950, hsa-miR-542-3p and PFKM. The results demonstrated that lncRNA XLOC_005950 expression was upregulated in OS tissues and cells. Functional experiments indicated that lncRNA XLOC_005950 knockout decreased PFKM activity, the intracellular glucose and lactic acid content, and cell proliferation, while increasing apoptosis of OS cells. Furthermore, lncRNA XLOC_005950 knockout upregulated hsa-miR-542-3p expression and downregulated PFKM expression. Overexpression of hsa-miR-542-3p suppressed PFKM expression. Furthermore, lncRNA XLOC_005950, as the molecular sponge of miR-542-3p in OS, modulated the downstream target gene, PFKM. Taken together, the results of the present study suggest that lncRNA XLOC_005950 knockout may inhibit the progression of OS via hsa-miR-542-3p-mediated regulation of PFKM expression.

Overexpression of Long Noncoding RNA LBX2-AS1 Promotes the Proliferation of Colorectal Cancer

Background:

LBX2 antisense RNA 1 (LBX2-AS1), a long noncoding RNA, has been identified to be closely associated with the progression of various cancers. However, the role of LBX2-AS1 in colorectal cancer (CRC) is still poorly understood. In this study, we aimed to investigate the expression and function of LBX2-AS1 in CRC.

Material and Methods:

Expression data from the Gene Expression Omnibus (GEO) and Gene Expression Profiling Interactive Analysis (GEPIA) databases and results obtained from clinical samples/patients were used to determine the correlation between LBX2-AS1 expression and pathological stages, overall survival (OS). Furthermore, knockdown of LBX2-AS1 in CRC cells using the short interfering RNA (siRNA) technique, and observed its biological functions using western blotting, quantitative reverse transcription-polymerase chain reaction (qRT-PCR), cell counting kit-8 (CCK-8) and flow cytometry assay in the CRC cell line.

Results:

Our study demonstrated that the expression levels of LBX2-AS1 were higher in CRC cell lines than in normal colon mucosal cell lines. Bioinformatics analysis revealed that CRC patients with high LBX2-AS1 expression levels had poor OS. Furthermore, knockdown of LBX2-AS1 in CRC cells could attenuate the proliferative ability of CRC cells in vitro, which is associated with decreased expression of cyclin-dependent kinase (CDK) 3, CDK6, and CCND1 and enhanced expression of cyclin-dependent kinase inhibitor 1A.

Conclusions:

LBX2-AS1 plays a crucial role in the tumorigenesis of CRC, providing a potential therapeutic target for CRC patients.

MicroRNA-381 targets G protein-Coupled receptor 34 (GPR34) to regulate the growth, migration and invasion of human cervical cancer cells

MicroRNAs (miRNAs) have emerged as the vital post-transcriptional regulators and control the growth and progression of different cancers types. The current study aimed at exploration of the role of microRNA-381 (miRNA-381) in human cervical cancer with emphasis on the evaluation of the underlying molecular mechanism. The results revealed a significant (P < 0.05) downregulation of miRNA-381 was found in cervical cancer tissues and cancer cell lines. Overexpression of miRNA-381 in cervical cancer cells significantly (P < 0.05) inhibited their proliferation through the induction of cell apoptosis which was accompanied by depletion of Bcl-2 and increase in Bax expression. Additionally, the cleavage of caspase-3 and 9 was also activated upon miRNA-381 overexpression. The Overexpression of miRNA-381 further inhibited the migration and invasion of cervical cancer cells. In silico analysis together with dual luciferase assay revealed G protein-Coupled receptor 34 (GPR34) to be the target of miRNA-381. The expression of GPR34 was significantly (P < 0.05) upregulated in the cervical cancer tissues and cell lines. Nonetheless, miRNA-381 overexpression caused a remarkable decrease in the expression of GPR34. The GPR34 knockdown and overexpression proved that the tumor-suppressive effects of miRNA-381 are mediated via GPR34. The study elucidated the essence of miRNA-381/GPR34 molecular regulatory axis in cervical cancer and unraveled the possibility of targeting this molecular axis as an important therapeutic approach against human cervical cancer.

Long noncoding RNA DLEU2 affects the proliferative and invasive ability of colorectal cancer cells

Emerging evidence indicates that long noncoding RNAs (lncRNAs) are closely associated with colorectal cancer (CRC) tumorigenesis. One example is lncRNA Deleted in Lymphocytic Leukemia 2 (DLEU2). However, how DLEU2 contributes to CRC is still poorly understood. This study sought to investigate the effects of DLEU2 on CRC pathogenesis, and the underlying mechanism involved. Using a quantitative real-time polymerase chain reaction (qRT-PCR) assay, we demonstrated that the expression levels of DLEU2 in 45 pairs of CRC tissues were higher than those in the corresponding normal colon mucosal tissues. In addition, CRC patients with high DLEU2 expression levels exhibited poor overall survival (OS) and recurrence-free survival (RFS), as determined by analyses and measurements from the GEO and GEPIA databases. When DLEU2 was silenced using short interfering RNA (siRNA) in CRC cell line, the results demonstrated that DLEU2 silencing suppressed CRC cell tumorigenesis in vitro, which was associated with decreased expression of cyclin dependent kinase 6(CDK6), ZEB1, and ZEB2 as well as enhancing the expression of Cyclin-dependent kinase inhibitor 1A (CDKN1A). Taken together, the results of this study suggested that DLEU2 may play critical roles in the progression of CRC and may serve as a prognostic biomarker for CRC.

MicroRNA-381-A Key Transcriptional Regulator: Its Biological Function and Clinical Application Prospects in Cancer

MicroRNAs (miRNAs) are small non-coding RNA molecules that function by regulating messenger RNAs. Recent studies have shown that miRNAs play important roles in multiple processes of cancer development. MiR-381 is one of the most important miRNAs in cancer progression. MiR-381 is downregulated in some cancers and upregulated in other cancers, including glioma, epithelial sarcoma, and osteosarcoma. MiR-381 regulates epithelial-mesenchymal transition (EMT), chemotherapeutic resistance, radioresistance, and immune responses. Thus, miR-381 participates in tumor initiation, progression, and metastasis. Moreover, miR-381 functions in various oncogenic pathways, including the Wnt/β-catenin, AKT, and p53 pathways. Clinical studies have shown that miR-381 could be considered a biomarker or a novel prognostic factor. Here, we summarize the present studies on the role of miR-381 in cancer development, including its biogenesis and various affected signaling pathways, and its clinical application prospects. MiR-381 expression is associated with tumor stage and survival time, making miR-381 a novel prognostic factor.

Clinical significance of dysregulation of miR-381 in pediatric acute myeloid leukemia

Background

microRNA-381 is dysregulated in a variety of cancers. However, its clinical significance in pediatric acute myeloid leukemia (AML) is still unclear. The purpose of this study was to detect the expression level of miR-381 in pediatric AML patients and to explore its potential clinical significance.

Methods

The levels of miR-381 in bone marrow and serum of 102 pediatric AML patients were measured by quantitative real-time polymorperase chain reaction (qRT-PCR). The diagnostic value of serum miR-381 in pediatric AML patients was evaluated by the receiver operating characteristic (ROC) curve. A Chi square test was used to analyze the relationship between serum miR-381 and the clinical characteristics of patients. Cox regression analysis and Kaplan–Meier evaluated the prognostic value of serum miR-381 in patients. Finally, the proliferation of the cells was analyzed by the CCK-8 assay.

Results

Compared with healthy controls, the levels of miR-381 in serum and bone marrow of pediatric AML patients were significantly decreased (P < 0.001). ROC curve showed that miR-381 could distinguish pediatric AML cases from normal controls. At the same time, the downregulation of miR-381 was associated with M7 in the French–American–British (FAB) classifications and unfavorable cytogenetic risks (P < 0.05). Low serum miR-381 levels were associated with poor overall survival of pediatric AML (log-rank test, P = 0.011) and poor relapse-free survival (log-rank test, P = 0.004). Cox regression analysis confirmed that reduced serum miR-381 was an independent predictor of poor prognosis in AML (HR = 3.794, 95% CI 1.3633–10.559, P = 0.011). In addition, low expression of miR-381 significantly reduced the proliferation of cells (P < 0.05).

Conclusion

All experimental results confirm that miR-381 has reduced bone marrow and serum expression in pediatric AML, and low levels of serum miR-381 have certain diagnostic and prognostic value in pediatric AML and may be a potential therapeutic target for AML.

MicroRNA-381-3p Functions as a Dual Suppressor of Apoptosis and Necroptosis and Promotes Proliferation of Renal Cancer Cells

Renal cell carcinoma (RCC) is the most common type of kidney cancer. It has a poor prognosis, with approximately 20-30% of patients developing recurrent and/or metastatic diseases that is relatively high resistant to conventional therapy. Resisting cell death is a hallmark of cancer cells. Apoptosis is a form of programmed cell death mediated by the activation of caspases. Necroptosis is a form of regulated necrosis that relies on the activation of receptor-interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain-like protein (MLKL), the substrate of RIPK3. Cancer cells often display apoptosis resistance via upregulation of anti-apoptotic genes and defective necroptosis due to the epigenetic silence of Ripk3. MicroRNAs (miRNAs) are non-coding small RNAs that are involved in numerous biological processes including cell proliferation, differentiation and death. In this study, we screened a set of ∼120 miRNAs for apoptosis-regulating miRNAs and identified miR-381-3p as a suppressor of TNF-induced apoptosis in various cancer cells. Ectopic expression of miR-381-3p inhibits the activation of caspase-8 and caspase-3. The expression level of miR-381-3p inversely correlates with the sensitivity of cancer cells to TNF-induced apoptosis. Moreover, we found that overexpression of miR-381-3p blocks TNF-induced necroptosis by inhibiting the activation of RIPK3 and MLKL. Of note, Kaplan-Meier Plotter analysis demonstrates that papillary RCC patients with high miR-381-3p expression have a lower overall survival than those with low expression level of miR-381-3p. Importantly, miR-381-3p overexpression promotes colony formation in human renal cancer cells. Thus, miR-381-3p acts as an oncogenic miRNA that counteracts both apoptotic and necroptotic signaling pathways. Our findings highlight miR-381-3p as a biomarker for predicting sensitivity to apoptosis and necroptosis, and as a possible therapeutic target for RCC.

Protective effect of microRNA‑381 against inflammatory damage of endothelial cells during coronary heart disease by targeting CXCR4

Coronary heart disease (CHD) is the leading cause of human morbidity and mortality worldwide. MicroRNA (miRNA) profiling is an innovative method of identifying biomarkers for many diseases and may be a powerful tool in the diagnosis and treatment of CHD. The present study aimed to analyze the effects of miRNA (miR)‑381 on the inflammatory damage of endothelial cells during CHD. A total of 21 patients with CHD and 21 healthy control patients were enrolled in this study. Reverse transcription‑quantitative PCR, western blotting and immunofluorescence assays were conducted to examine the expression levels of miR‑381, C‑X‑C chemokine receptor type 4 (CXCR4), Bcl‑2, Bax, Cleaved‑Caspases‑3 and ‑9, p38, ERK1/2 and JNK. Cell Counting Kit‑8, EdU and flow cytometry experiments were performed to evaluate cell proliferation and apoptosis. An ELISA was adopted to determine the expressions of inflammatory factors (interleukins‑8, ‑6 and ‑1β, and tumor necrosis factor‑α). In addition, a dual‑luciferase reporter assay was used to determine the relationship between miR‑381 and CXCR4. Decreased miR‑381 expression and increased CXCR4 expression in the plasma were observed in the CHD group compared with the normal group, which indicated a negative relationship between miR‑381 and CXCR4. Overexpression of miR‑381 significantly promoted the proliferation and inhibited the apoptosis of oxidized low‑density lipoprotein (OX‑LDL)‑induced human umbilical vein endothelial cells (HUVECs) through mitogen‑activated protein kinase pathway by targeting and inhibiting CXCR4. Furthermore, overexpression of miR‑381 reduced the release of inflammatory factors in OX‑LDL‑induced HUVECs. By contrast, reduced expression of miR‑381 exerted the opposite effects, which were subsequently reversed by silencing CXCR4 expression. Results from the present study indicated that miR‑381 was a CHD‑related factor that may serve as a potential molecular target for CHD treatment.

SNHG15 Contributes To Cisplatin Resistance In Breast Cancer Through Sponging miR-381

Background

Increasing evidence implies the participation of long non-coding RNAs (lncRNAs) in chemoresistance to cancer treatment. Their role and molecular mechanisms in breast cancer chemoresistance, nevertheless, are yet not considerably elucidated. In this work, we research the function of small nucleolar RNA host gene 15 (SNHG15) in cisplatin (DDP) resistance of breast cancer and uncover the underlying molecular mechanism.

Methods

SNHG15 and miR-381 expression levels were detected using Quantitative real-time PCR (qRT-PCR) analysis. The functional roles of SNHG15 and miR-381 in breast cancer were determined using MTT assay and flow cytometry analysis. The effect of SNHG15 on miR-381 expression was determined using Luciferase reporter assay, RNA immunoprecipitation (RIP) assay and qRT-PCR analysis.

Results

SNHG15 was found to be up-regulated in cisplatin resistant breast cancer tissues and cell lines. Breast cancer patients with high SNHG15 expression had a poor prognosis. SNHG15 silencing enhanced cisplatin sensitivity of MCF-7/DDP and MDA-MB-231/DDP cells. Additionally, SNHG15 could function as a miR-381 sponge. miR-381 overexpression could overcome cisplatin resistance. miR-381 knockdown countered SNHG15 knockdown-mediated enhancement of cisplatin sensitivity in MCF-7/DDP and MDA-MB-231/DDP cells. Besides, SNHG15 knockdown facilitated cisplatin sensitivity of cisplatin resistant breast cancer cells in vivo.

Conclusion

In summary, SNHG15 knockdown overcame cisplatin resistance of breast cancer by sponging miR-381, providing a novel therapeutic target for breast cancer.

miRNA signatures in childhood sarcomas and their clinical implications

Progresses in multimodal treatments have significantly improved the outcomes for childhood cancer. Nonetheless, for about one-third of patients with Ewing sarcoma, rhabdomyosarcoma, or osteosarcoma steady remission has remained intangible. Thus, new biomarkers to improve early diagnosis and the development of precision-targeted medicine remain imperative. Over the last decade, remarkable progress has been made in the basic understanding of miRNAs function and in interpreting the contribution of their dysregulation to cancer development and progression. On this basis, this review focuses on what has been learned about the pivotal roles of miRNAs in the regulation of key genes implicated in childhood sarcomas.

EZH2 Contributes To Cisplatin Resistance In Breast Cancer By Epigenetically Suppressing miR-381 Expression

BACKGROUND

Emerging evidence reveals the vital role of enhancer of zeste homolog 2 (EZH2) in cancer chemoresistance. However, its function and molecular mechanisms in breast cancer chemoresistance remain largely unknown.

METHODS

Gene expression was evaluated using quantitative real-time PCR (qRT-PCR) and Western blot analysis. The functional roles of EZH2 and miR-381 in breast cancer were explored using cell MTT assay and flow cytometry analysis. The effect of EZH2 on miR-381 expression in transcriptional level was determined using Chromatin immunoprecipitation (ChIP) assay and Luciferase reporter assay.

RESULTS

In this study, we found that EZH2 was up-regulated in CDDP-resistant breast cancer tissues and cell lines. Breast cancer patients with high EZH2 expression had a poor prognosis. EZH2 silencing improved the sensitivity of MCF-7/CDDP and MDA-MB-231/CDDP cells towards CDDP. Moreover, EZH2 could epigenetically silence miR-381. miR-381 overexpression could overcome CDDP resistance in CDDP-resistant breast cancer cells. miR-381 knockdown weakened the inductive effect of EZH2 silencing on CDDP sensitivity of MCF-7/CDDP and MDA-MB-231/CDDP cells. Furthermore, EZH2 knockdown facilitated CDDP sensitivity of CDDP-resistant breast cancer cells in vivo.

CONCLUSIONS

Collectively, EZH2 depletion overcame CDDP resistance of breast cancer through epigenetically silencing miR-381, providing a novel therapeutic target for breast cancer chemoresistance.

Up-regulation of LINC00467 promotes the tumourigenesis in colorectal cancer

Recent studies have reported that long non-coding RNAs (lncRNAs) are associated with the tumourigenesis of colorectal cancer (CRC); however, several of these are yet to be identified and characterised. In this study, we report a novel lncRNA, LINC00467, which was significantly up-regulated in CRC; we investigated its function and mechanism in CRC. Our study demonstrated that LINC00467 levels in 45 pairs of CRC tissues were higher than those in the corresponding normal colon mucosal tissues. We used the Gene Expression Omnibus (GEO) and Gene Expression Profiling Interactive Analysis (GEPIA) databases for the analysis and measurement of clinical samples, and observed that the CRC patients with high LINC00467 expression levels showed poor overall survival (OS) and recurrent-free survival (RFS) rates. Furthermore, following the short interfering RNA (siRNA) knockdown of LINC00467 in the CRC cell line, the results demonstrated that LINC00467 suppresses the proliferation, invasion and metastasis of CRC cells in vitro. Moreover, its molecular mechanism of LINC00467 decreased the expression of Cyclin D1, Cyclin A1, CDK2, CDK4 and Twist1 as well as enhanced the expression of E‑cadherin. Collectively, these findings suggest that LINC00467 may be crucial in the progression and development of CRC, and may serve as a potential therapeutic target for CRC patients.

Serum microRNA-381: A Potential Marker for Early Diagnosis of Gastric Cancer

PURPOSE

The purpose of this study was to explore the potential early diagnostic value of serum microRNA-381(miRNA-381) in patients with gastric cancer (GC).

MATERIALS AND METHODS

Patients with advanced gastric cancer (AGC) and early gastric cancer (EGC), as well as healthy individuals, were enrolled in this study. Expression of miRNA-381 in serum was detected using real-time quantitative PCR. Electrochemiluminescence analysis was used to investigate the expression of classic tumor markers, including carbohydrate antigen (CA) 199, CA724, and carcinoembryonic antigen. Finally, receiver operating characteristic curve and Kaplan-Meier analysis were used to determine the value of miRNA-381 in clinical diagnosis of GC.

RESULTS

miRNA-381 was differentially expressed among the study groups. AUC analysis showed that the sensitivity and specificity of serum miRNA-381 in the diagnosis of GC were superior to those of other tumor markers. Furthermore, low levels of miRNA-381 expression were positively correlated with lymph node metastasis and AGC. Finally, Kaplan-Meier survival analysis showed that down-regulation of miRNA-381 was associated with lymph node metastasis and the development of GC.

CONCLUSION

miRNA381, which was down-regulated in GC, might be a novel early diagnosis marker for patients with GC.

miR‑381 functions as a tumor suppressor by targeting ETS1 in pancreatic cancer

Increasing evidence shows that microRNA (miR)-381 is involved in the carcinogenesis and biologic progression of various types of cancer in humans. However, its potential biologic role and mechanism in pancreatic cancer remain to be elucidated. In the present study, the expression and functional role of miR-381 in pancreatic cancer were investigated. It was found that miR-381 was significantly downregulated in pancreatic cancer tissues and cell lines. The biological functions of miR-381 were examined by measuring cell proliferation, migration, invasion and apoptosis in vitro and in vivo. The miR-381 target gene and signaling pathway were identified by luciferase activity assay and western blot assay. In vitro experiments confirmed that the enforced expression of miR-381 markedly suppressed cell proliferation, migration and invasion, and induced apoptosis in pancreatic cancer cells. By contrast, silencing the expression of miR-381 had the opposite effect. In addition, miR-381 inhibited xenograft tumor growth in vivo. Furthermore, ETS1 was identified as a direct target of miR-381, and western blot analysis showed that miR-381 negatively modulated the expression of ETS1. It was also demonstrated that miR-381 serves a key role in pancreatic cancer cells through regulating the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway. In conclusion, the data obtained suggested that miR-381 mediated cell proliferation, migration and invasion by targeting ETS1, partly through PI3K/AKT/mTOR signaling pathway. These results provide novel insights into understanding the potential effects and molecular mechanism of miR-381 on pancreatic cancer. miR-381 may serve as a novel potential marker for pancreatic cancer treatment in the future.

miR-381 overcomes cisplatin resistance in breast cancer by targeting MDR1

Increasing evidence suggests the involvement of microRNA-381 (miR-381) in chemoresistance of cancer treatment. However, its function and molecular mechanisms in breast cancer chemoresistance are still not well elucidated. In the present study, we aimed to investigate the functional role of miR-381 in cisplatin (DDP) resistance of breast cancer and discover the underlying molecular mechanism. The expression levels of miR-381 and MDR1 were detected by quantitative real-time PCR (qRT-PCR) and Western blot analysis in breast cancer tissues and cell lines. The DDP sensitivity and cell apoptosis of breast cancer cells were determined by MTT assay and flow cytometric analysis, respectively. The relationship between miR-381 and MDR1 was explored by target prediction and luciferase reporter analysis. miR-381 was decreased in DDP-resistant breast cancer tissues and cell lines. Low miR-381 expression was correlated with poor prognosis of breast cancer patients. miR-381 overexpression improved DDP sensitivity of MCF-7/DDP and MDA-MB-231/DDP cells. Conversely, miR-381 inhibition lowered the response of MCF-7 and MDA-MB-231 to DPP. Moreover, miR-381 could directly suppress multidrug resistance 1 (MDR1) expression. MDR1 knockdown could overcome DDP resistance in MCF-7/DDP and MDA-MB-231/DDP cells, while MDR1 overexpression led to DDP resistance in MCF-7 and MDA-MB-231 cells. Notably, MDR1 overexpression counteracted the inductive effect of miR-381 mimics on DDP sensitivity of MCF-7/DDP and MDA-MB-231/DDP cells. On the contrary, miR-381 inhibition-mediated DDP resistance in MCF-7 and MDA-MB-231 cells was reversed by MDR1 knockdown. In summary, miR-381 could overcome DDP resistance of breast cancer by directly targeting MDR1, providing a novel therapeutic target for breast cancer chemoresistance.

miR‑381 and miR‑489 suppress cell proliferation and invasion by targeting CUL4B via the Wnt/β‑catenin pathway in gastric cancer

Accumulating evidence has highlighted the critical role of cullin 4B (CUL4B) in driving tumourigenesis in several malignancies, including gastric cancer (GC); however, the mechanisms underlying CUL4B upregulation remain unclear. The dysregulation of microRNAs (miRNAs or miRs) is known to be involved in tumourigenesis. In this study, we report that the expression of miR‑381 and miR‑489 is downregulated and is negatively correlated with that of CUL4B in GC tissues and cell lines. Further analysis verified that miR‑381 and miR‑489 directly targeted CUL4B. CUL4B silencing inhibited cell proliferation, migration and invasion by inactivating the Wnt/β‑catenin pathway. miR‑381/miR‑489 overexpression recapitulated the effects of CUL4B silencing, while CUL4B restoration negated the suppressive effects induced by the ectopic expression of miR‑381/miR‑489. Furthermore, miR‑381/miR‑489 exerted tumour suppressive functions by inactivating the Wnt/β‑catenin pathway through the targeting of CUL4B. Taken together, the findings of this study suggest that the miR‑381/miR‑489‑mediated expression of CUL4B modulates the proliferation and invasion of GC cells via the Wnt/β‑catenin pathway, which indicates that the miR‑381/miR‑489‑CUL4B axis is critical in the control of GC tumourigenesis.

miR-381 induces sensitivity of breast cancer cells to doxorubicin by inactivation of MAPK signaling via FYN

The emergence of drug resistance is still a daunting challenge for the effective therapy of cancer patients. miRNAs have been elucidated as an important regulator in chemoresistance of anti-cancer drugs. miR-381 is found to exert tumor-suppressive effect in breast cancer. However, its role in modulating the sensitivity of doxorubicin (DOX) remains unknown. In this study, we found that miR-381 expression was down-regulated in DOX-resistant breast cancer cells. miR-381 overexpression increased DOX sensitivity and enhanced DOX-induced apoptosis in breast cancer cells. Moreover, miR-381 could directly target FYN to suppress its expression. Additionally, FYN knockdown displayed similar effect on DOX sensitivity as miR-381 up-regulation. Furthermore, FYN overexpression partly reversed miR-381-induced sensitivity to DOX. Finally, enforced expression of miR-381 also improved DOX sensitivity of breast cancer cells in vivo. In summary, miR-381 inactivated MAPK signaling by down-regulating FYN, thereby promoting the chemosensitization of breast cancer cells to DOX. Therefore, miR-381/FYN/MAPK pathway may be applied as a novel target to overcome DOX resistance in breast cancer patients.

miR-381-3p restrains cervical cancer progression by downregulating FGF7

This study aimed at elucidating the molecular mechanism of miR-381-3p in cervical cancer progression, which may provide a novel therapeutic target for patients with cervical cancer. The expression of miR-381-3p was confirmed by quantitative reverse transcription polymerase chain reaction. Microarray analysis was conducted to screen out differentially expressed genes, and the target gene of microRNA (miRNA) was predicted on TargetScan. Dual-luciferase reporter assay then verified the targeting relationship between miR-381-3p and FGF7. The protein expression of FGF7 was examined via Western blot assay. Colony formation assay was used to detect the cell proliferation, while flow cytometry was used to analyze cell cycle and apoptosis. The influence of miR-381-3p and FGF7 on cell migration and invasion was confirmed by transwell migration/invasion assay. Finally, we demonstrated that miR-381-3p was lowly expressed, while FGF7 was highly expressed in cervical cancer cells. There was a direct target relationship and a negative correlation between miR-381-3p and FGF7. miR-381-3p could downregulate FGF7 expression, inhibiting cell proliferation and metastasis, and inducing cell cycle arrest and apoptosis in cervical cancer.

Overexpression of miR-381 relieves neuropathic pain development via targeting HMGB1 and CXCR4

MicroRNA are significant regulators of neuropathic pain development. Neuroinflammation contributes a lot to the progression of neuropathic pain. miR-381 is involved in various pathological processes. However, the role of miR-381 in neuropathic pain development remains barely understood. Therefore, in our study, we aimed to investigate the effects of miR-381 on the process of neuropathic pain progression by establishing a rat model using chronic sciatic nerve injury (CCI). Here, we observed that miR-381 was dramatically decreased in CCI rats. Up-regulation of miR-381 strongly reduced neuropathic pain behaviors including mechanical and thermal hyperalgesia. In addition, inflammatory cytokine expression, including IL-6, IL-10 and TNF-α were significantly repressed by overexpression of miR-381. High mobility group box 1 protein (HMGB1) and Chemokine CXC receptor 4 (CXCR4) participate in neuropathic pain development. In our present study, HMGB1 and CXCR4 were predicted as direct targets of miR-381 by employing bioinformatics analysis. Overexpression of miR-381 was able to restrain the expression of HMGB1 and CXCR4 greatly. The direct correlation between HMGB1 and CXCR4 and miR-381 was confirmed in our research. Furthermore, we found that HMGB1 and CXCR4 were increased in CCI rats time-dependently. Moreover, it was demonstrated that silence of HMGB1 and CXCR4 in CCI rats depressed neuropathic pain progression greatly. In conclusion, it was indicated that miR-381could inhibit neuropathic pain development through targeting HMGB1 and CXCR4.

Deep RNA sequencing reveals the dynamic regulation of miRNA, lncRNAs, and mRNAs in osteosarcoma tumorigenesis and pulmonary metastasis

Osteosarcoma (OS) is the most common pediatric malignant bone tumor, and occurrence of pulmonary metastasis generally causes a rapid and fatal outcome. Here we aimed to provide clues for exploring the mechanism of tumorigenesis and pulmonary metastasis for OS by comprehensive analysis of microRNA (miRNA), long non-coding RNA (lncRNA), and mRNA expression in primary OS and OS pulmonary metastasis. In this study, deep sequencing with samples from primary OS (n = 3), pulmonary metastatic OS (n = 3), and normal controls (n = 3) was conducted and differentially expressed miRNAs (DEmiRNAs), lncRNAs (DElncRNAs), and mRNAs (DEmRNAs) between primary OS and normal controls as well as pulmonary metastatic and primary OS were identified. A total of 65 DEmiRNAs, 233 DElncRNAs, and 1405 DEmRNAs were obtained between primary OS and normal controls; 48 DEmiRNAs, 50 DElncRNAs, and 307 DEmRNAs were obtained between pulmonary metastatic and primary OS. Then, the target DEmRNAs and DElncRNAs regulated by the same DEmiRNAs were searched and the OS tumorigenesis-related and OS pulmonary metastasis-related competing endogenous RNA (ceRNA) networks were constructed, respectively. Based on these ceRNA networks and Venn diagram analysis, we obtained 3 DEmiRNAs, 15 DElncRNAs, and 100 DEmRNAs, and eight target pairs including miR-223-5p/(CLSTN2, AC009951.1, LINC01705, AC090673.1), miR-378b/(ALX4, IGSF3, SULF1), and miR-323b-3p/TGFBR3 were involved in both tumorigenesis and pulmonary metastasis of OS. The TGF-β superfamily co-receptor TGFBR3, which is regulated by miR-323b-3p, acts as a tumor suppressor in OS tumorigenesis and acts as a tumor promoter in pulmonary metastatic OS via activation of the epithelial-mesenchymal transition (EMT) program.In conclusion, the OS transcriptome (miRNA, lncRNA, and mRNA) is dynamically regulated. These analyses might provide new clues to uncover the molecular mechanisms and signaling networks that contribute to OS progression, toward patient-tailored and novel-targeted treatments.

Coagulation Factor X Regulated by CASC2c Recruited Macrophages and Induced M2 Polarization in Glioblastoma Multiforme

Tumor-associated macrophages (TAMs) constitute a major component of inflammatory cells in the glioblastoma multiforme (GBM) tumor microenvironment. TAMs have been implicated in GBM angiogenesis, invasion, local tumor recurrence, and immunosuppression. Coagulation factor X (FX) is a vitamin K-dependent plasma protein that plays a role in the regulation of blood coagulation. In this study, we first found that FX was highly expressed and positively correlated with TAM density in human GBM. FX exhibited a potent chemotactic capacity to recruit macrophages and promoted macrophages toward M2 subtype polarization, accelerating GBM growth. FX bound to extracellular signal-related kinase (ERK)1/2 and inhibited p-ERK1/2 in GBM cells. FX was secreted in the tumor microenvironment and increased the phosphorylation and activation of ERK1/2 and AKT in macrophages, which may have been responsible for the M2 subtype macrophage polarization. Moreover, although the lncRNA CASC2c has been verified to function as a miR-101 competing endogenous RNA (ceRNA) to promote miR-101 target genes in GBM cells, we first confirmed that CASC2c did not function as a miR-338-3p ceRNA to promote FX expression, and that FX was a target gene of miR-338-3p. CASC2c interacted with and reciprocally repressed miR-338-3p. Both CASC2c and miR-388-3p bound to FX and commonly inhibited its expression and secretion. CASC2c repressed M2 subtype macrophage polarization. Taken together, our findings revealed a novel mechanism highlighting CASC2c and FX as potential therapeutic targets to improve GBM patients by altering the GBM microenvironment.

CXCR4-mediated osteosarcoma growth and pulmonary metastasis is suppressed by MicroRNA-613

Osteosarcoma is the most common primary bone malignancy. Recently, studies showed chemokine receptor 4 (CXCR4) played a critical role in osteosarcoma. However, the regulation of CXCR4 is not fully understood. microRNAs are short, non‐coding RNAs that play an important roles in post‐transcriptional regulation of gene expression in a variety of diseases including osteosarcoma. miR‐613 is a newly discovered miRNA and has been reported to function as a tumor suppressor in many cancers. In this study, we confirmed that both Stromal Cell‐Derived Factor (SDF‐1) and CXCR4 could be prognostic markers for osteosarcoma. Meanwhile this study found that SDF‐1/CXCR4 pathway regulated osteosarcoma cells proliferation, migration and reduced apoptosis. Besides, we demonstrated that miR‐613 was significantly downregulated in osteosarcoma patients. Elevated expression of miR‐613 directly suppressed CXCR4 expression and then decreased the proliferation, migration and induced apoptosis of osteosarcoma cells. Moreover, our study found that CXCR4 promoted the development of lung metastases and inhibition of CXCR4 by miR‐613 reduced lung metastases. These data indicated that CXCR4 mediated osteosarcoma cell growth and lung metastases and this effect can be suppressed by miR‐613 through directly downregulating CXCR4.

MicroRNA-381 inhibits cell proliferation and invasion in endometrial carcinoma by targeting the IGF-1R

Endometrial carcinoma (EC) is the sixth most common type of malignant tumor occurring in females. MicroRNAs (miRNAs) serve as oncogenes or tumor suppressors in human cancer and play important roles in tumorigenesis, and tumor development by regulating various processes. Thus, further investigation into miRNAs involved in EC formation and progression may aid in developing effective therapeutic strategies for patients with this disease. miRNA‑381 (miR‑381) is aberrantly expressed in multiple types of human cancer. However, the expression pattern, biological roles and underlying mechanisms of miR‑381 in EC are poorly understood. In the present study, the results showed that miR‑381 was downregulated in EC tissues and cell lines. Decreased miR‑381 expression correlated with the International Federation of Gynecology and Obstetrics stage, lymph nodes metastasis and myometrial invasion of EC. The ectopic expression of miR‑381 significantly inhibited the proliferation and invasion of EC cells. Through a series of experiments, the insulin‑like growth factor receptor 1 (IGF‑1R) was identified as a novel direct target of miR‑381 in EC. Furthermore, IGF‑1R was highly expressed in EC tissues and inversely correlated with miR‑381 levels. IGF‑1R overexpression partially abrogated the tumor‑suppressive effects of miR‑381 on the proliferation and invasion of EC cells. miR‑381 targeted IGF‑1R to inactivate the protein kinase B (AKT) and extracellular signal‑regulated kinase (ERK) signaling pathways in EC. These results suggest that miR‑381 acts as a tumor suppressor in EC by directly targeting IGF‑1R, and indirectly regulating the AKT and ERK signaling pathways. Thus, miR‑381 should be investigated as a prognostic biomarker and novel therapeutic target for the treatment of patients with EC.

Downregulation of miR-381 is associated with poor prognosis in papillary thyroid carcinoma

Circulating microRNAs (miRNAs) are potential biomarkers for papillary thyroid carcinoma (PTC). The aim of this study was to evaluate the diagnostic and prognostic value of serum miR-381 in PTC. A total of 87 patients with PTC, 50 cases with benign thyroid nodules (BTN) and 50 healthy volunteers were enrolled. The expression levels of serum miR-381 were measured using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The results indicated that serum miR-381 expression was significantly decreased in PTC patients compared to that of BTN patients or healthy controls. Moreover, serum miR-381 showed good performance to differentiate PTC cases from controls. Next, reduced serum miR-381 expression was positively correlated with aggressive clinical features and shorter overall survival. Furthermore, serum miR-381 levels were greatly elevated in 21 patients with advanced-stage (stage III/IV) PTC after surgery. Finally, univariate and multivariate Cox regression analysis confirmed that miR-381 in serum was an independent prognostic indicator for OS in PTC patients. Collectively, serum miR-381 might serve as a non-invasive biomarker for the diagnosis and prognosis of PTC.

MicroRNA-381 serves as a prognostic factor and inhibits migration and invasion in non-small cell lung cancer by targeting LRH-1

Accumulating evidence has demonstrated that aberrant miRNAs were involved in carcinogenesis and tumor progression by regulating oncogenes or tumor suppressor expression. Dysregulation of miR-381 has been reported in different tumors. However, the clinical roles and underlying mechanism in non-small cell lung cancer (NSCLC) remains to be elucidated. We found the expression of miR-381 was significantly downregulated in both NSCLC tissues and cell lines. Clinical analysis revealed the reduced miR-381 was obviously associated with advanced TNM stage and lymph node metastasis. Moreover, we disclosed that miR-381 was a novel independent prognostic marker for predicting 5-year survival of NSCLC patients. The ectopic overexpression of miR-381 inhibited cell migration and invasion in vitro and in vivo. Notably, miR-381 could modulate LRH-1 by directly binding to its 3'-UTR. In clinical samples of NSCLC, miR-381 inversely correlated with LRH-1 expression, which performed positive roles in NSCLC migration and invasion. Alteration of LRH-1 expression at least partially abolished the migration and invasion of miR-381 on NSCLC cells. Here, we identified LRH-1 as a functional target of miR-381 in NSCLC. In conclusion, our data indicated that miR-381 inhibited migration and invasion of NSCLC by targeting LRH-1, and may represent a novel potential therapeutic target and prognostic marker for NSCLC.

MiR-381 inhibits migration and invasion in human gastric carcinoma through downregulatedting SOX4

Aberrant expression of microRNAs (miRs) serves essential roles in the generation and progression of various types of human cancer. In the present study, the expression and biological functions of miR-381 in human gastric carcinoma (GC) were focused upon. The results of reverse transcription-quantitative polymerase chain reaction analysis revealed that the expression of miR-381 was significantly downregulated in GC tissue samples. Furthermore, low expression of miR-381 was identified to be associated with lymphatic metastasis and advanced tumor-node-metastasis stage (III+IV). Upregulation of miR-381 inhibited the migration and invasion of GC SGC-7901 cells through SRY-Box 4 (SOX4)-mediated epithelial-mesenchymal transition. Finally, long non-coding (lnc) RNA-taurine upregulatedted 1 (non-protein coding) (TUG1) was confirmed as a negatively regulator of miR-381 expression in SGC-7901 cells. Taken together, the results of the current study indicate that the downregulation of miR-381 by lncRNA-TUG1 promoted the metastasis of GC cells by inhibiting SOX4. Thus, targeting miR-381 may be a novel therapeutic option for the treatment of patients with GC.

Macrophage migration inhibitory factor promotes osteosarcoma growth and lung metastasis through activating the RAS/MAPK pathway

Emerging evidence suggests that the tumour microenvironment plays a critical role in osteosarcoma (OS) development. Thus, cytokine immunotherapy could be a novel strategy for OS treatment. In this study, we explored the role of macrophage migration inhibitory factor (MIF), an important cytokine in OS progression, and investigated the anti-tumour effects of targeting MIF in OS. The results showed that MIF significantly increased in the tissue and serum samples of OS patients and was associated with tumour size, pulmonary metastasis and the survival rate of OS patients. We verified a positive correlation between MIF and p-ERK1/2 in OS patients. The in vitro results indicated that MIF could activate the RAS/MAPK pathway in a time- and dose-dependent manner, thereby promoting cell proliferation and migration. Furthermore, shRNA targeting MIF significantly inhibited tumour growth and lung metastasis in a mouse xenograft model and orthotopic model of OS. Additionally, inhibition of MIF significantly enhanced the sensitivity of OS cells to cisplatin and doxorubicin. Our findings suggest that immunotherapy targeting MIF to block the RAS/MAPK kinase cascade may represent a feasible and promising approach for OS treatment.

SIX3, a tumor suppressor, inhibits astrocytoma tumorigenesis by transcriptional repression of AURKA/B

BACKGROUND

SIX homeobox 3 (SIX3) is a member of the sine oculis homeobox transcription factor family. It plays a vital role in the nervous system development. Our previous study showed that the SIX3 gene is hypermethylated, and its expression is decreased in astrocytoma, but the role of SIX3 remains unknown.

METHODS

Chromatin-immunoprecipitation (ChIP) and luciferase reporter assay were used to confirm the binding of SIX3 to the promoter regions of aurora kinase A (AURKA) and aurora kinase B (AURKB). Confocal imaging and co-immunoprecipitation (Co-IP) were used to detect the interaction between AURKA and AURKB. Flow cytometry was performed to assess the effect of SIX3 on cell cycle distribution. Colony formation, EdU incorporation, transwell, and intracranial xenograft assays were performed to demonstrate the effect of SIX3 on the malignant phenotype of astrocytoma cells.

RESULTS

SIX3 is identified as a novel negative transcriptional regulator of AURKA and AURKB, and it decreases the expression of AURKA and AURKB in a dose-dependent manner in astrocytoma cells. Importantly, interactions between AURKA and AURKB stabilize and protect AURKA/B from degradation, and overexpression of SIX3 does not affect these interactions; SIX3 also acts as a tumor suppressor, and it increases p53 activity and expression at the post-translational level by the negative regulation of AURKA or AURKB, reduces the events of numerical centrosomal aberrations and misaligned chromosomes, and significantly inhibits the proliferation, invasion, and tumorigenesis of astrocytoma in vitro and in vivo. Moreover, experiments using primary cultured astrocytoma cells indicate that astrocytoma patients with a low expression of SIX3 and mutant p53 are more sensitive to treatment with aurora kinase inhibitors.

CONCLUSION

SIX3 is a novel negative transcriptional regulator and acts as a tumor suppressor that directly represses the transcription of AURKA and AURKB in astrocytoma. For the first time, the functional interaction of AURKA and AURKB has been found, which aids in the protection of their stability, and partially explains their constant high expression and activity in cancers. SIX3 is a potential biomarker that could be used to predict the response of astrocytoma patients to aurora kinase inhibitors.

miR-381-3p suppresses the proliferation of oral squamous cell carcinoma cells by directly targeting FGFR2

Mutiple microRNAs are implicated in oral squamous cell carcinoma (OSCC), which is characterized by a high rate of proliferation and nodal metastasis. Data from the present study showed that miR-381-3p is significantly underexpressed in both OSCC tissues and cell lines. Overexpression of miR-381-3p led to marked suppression of proliferation and cell cycle progression of OSCC cells and promotion of apoptosis. Notably, fibroblast growth factor receptor 2 (FGFR2) was downregulated by miR-381-3p through direct interactions with its 3' untranslated region. Knockdown of FGFR2 recapitulated the growth suppressive effect of miR-381-3p. Conversely, restoring FGFR2 expression attenuated miR-381-3p-induced effects in OSCC cells. Expression patterns of miR-381-3p and FGFR2 were inversely correlated in OSCC tissues. Our collective results provide novel evidence that miR-381-3p acts as a tumor suppressor in OSCC by directly targeting FGFR2, thereby presenting a promising therapeutic target.

MicroRNA-381 inhibits the metastasis of gastric cancer by targeting TMEM16A expression

Background

MicroRNA-381 (miR-381) has been reported to play suppressive or promoting roles in different malignancies. However, the expression level, biological function, and underlying mechanisms of miR-381 in gastric cancer remain poorly understood. Our previous study indicated that transmembrane protein 16A (TMEM16A) contributed to migration and invasion of gastric cancer and predicted poor prognosis. In this study, we found that miR-381 inhibited the metastasis of gastric cancer through targeting TMEM16A expression.

Methods

MiR-381 expression was analyzed using bioinformatic software on open microarray datasets from the Gene Expression Omnibus (GEO) and confirmed by quantitative RT-PCR (qRT-PCR) in human gastric cancer tissues and cell lines. Cell proliferation was investigated using MTT and cell count assays, and cell migration and invasion abilities were evaluated by transwell assay. Xenograft nude mouse models were used to observe tumor growth and pulmonary metastasis. Luciferase reporter assay, western blot, enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry were employed to explore the mechanisms of the effect of miR-381 on gastric cancer cells.

Results

MiR-381 was significantly down-regulated in gastric cancer tissues and cell lines. Low expression of miR-381 was negatively related to lymph node metastasis, advanced tumor stage and poor prognosis. MiR-381 decreased gastric cancer cell proliferation, migration and invasion in vitro and in vivo. TMEM16A was identified as a direct target of miR-381 and the expression of miR-381 was inversely correlated with TMEM16A expression in gastric cancer tissues. Combination analysis of miR-381 and TMEM16A revealed the improved prognostic accuracy for gastric cancer patients. Moreover, miR-381 inhibited TGF-β signaling pathway and down-regulated epithelial–mesenchymal transition (EMT) phenotype partially by mediating TMEM16A.

Conclusions

MiR-381 may function as a tumor suppressor by directly targeting TMEM16A and regulating TGF-β pathway and EMT process in the development of progression of gastric cancer. MiR-381/TMEM16A may be a novel therapeutic candidate target in gastric cancer treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-017-0499-z) contains supplementary material, which is available to authorized users.