MicroRNA-126 inhibits osteosarcoma cells proliferation by targeting Sirt1

Numerous studies have recently suggested that miRNAs contribute to the development of various types of human cancer as well as to their proliferation and metastasis. The aim of this study was to investigate the functional significance of miR-126 and to identify its possible target genes in osteosarcoma (OS) cells. Here, we found that expression level of miR-126 was reduced in osteosarcoma cells in comparison with the adjacent normal tissues. The enforced expression of miR-126 was able to inhibit cell proliferation in U2OS and MG62 cells, while miR-126 antisense oligonucleotides (antisense miR-126) promoted cell proliferation. At the molecular level, our results further revealed that expression of Sirt1, a member of histone deacetylase, was negatively regulated by miR-126. Therefore, the data reported here demonstrate that miR-126 is an important regulator in osteosarcoma, which will contribute to better understanding of the important misregulated miRNAs in osteosarcoma cells.     

MicroRNA-32 inhibits osteosarcoma cell proliferation and invasion by targeting Sox9

Increasing reports suggest that discovery of microRNAs (miRNAs) might provide a novel therapeutical target for human cancers, including osteosarcoma. Previous studies have shown that miR-32 was dysregulated in breast and endometrial cancer. However, its biological roles in osteosarcoma remain unclear. In the current study, we found that miR-32 was significantly down-regulated in osteosarcoma tissues, compared with the adjacent normal tissues. In vitro studies further demonstrated that miR-32 mimics were able to suppress, while its antisense oligos promoted cell proliferation in Saos-2 and U2OS cells. At the molecular level, our data further revealed that expression of Sox9 was negatively regulated by miR-32. Therefore, our results identify an important role for miR-32 in the osteosarcoma through regulating Sox9 expression.     

MicroRNA-128 promotes proliferation in osteosarcoma cells by downregulating PTEN

MicroRNAs are a class of small noncoding RNAs that function as critical gene regulators through targeting mRNAs for translational repression or degradation. Several studies have indicated that abnormal expression of miRNAs occurs frequently in human osteosarcoma. In the present study, we found that miR-128 expression was significantly increased in osteosarcoma tissues compared to adjacent normal tissues. Ectopic overexpression of miR-128 significantly promoted while suppression of miR-128 by its antisense inhibited the proliferation of MG63 and U2OS cells. At the molecular level, our results demonstrated that miR-128 overexpression could repress expression of PTEN by directly targeting PTEN 3'-untranslated region. Consistently, downstream AKT signaling was altered by miR-128 overexpression or knockdown. Therefore, our results suggest that miR-128 plays an important role in the proliferation of human osteosarcoma cells by directly regulation of PTEN/AKT signaling.     

MicroRNA-802 Promotes Osteosarcoma Cell Proliferation by Targeting p27

MicroRNAs have been demonstrated to regulate proliferation and apoptosis in many types of cancers, butbiological functions in osteosarcomas remain relatively unknown. Here, we found expression of miR-802 to beup-regulated in osteosarcoma tissues in comparison with adjacent normal tissues. Enforced expression of miR-802was able to promote cell proliferation in U2OS and MG63 cells, while miR-802 antisense oligonucleotides (antisensemiR-802) inhibited cell proliferation. At the molecular level, our results further revealed that expression of p27,a negative cell-cycle regulator, was negatively regulated by miR-802. Therefore, the data reported here indicatethat miR-802 is an important regulator in osteosarcoma, our findings contributing to a better understanding ofimportant mis-regulated miRNAs in this tumour type.     

MicroRNA-320 inhibits osteosarcoma cells proliferation by directly targeting fatty acid synthase

Increasing evidence has demonstrated that small noncoding microRNAs (miRNAs) could contribute to cancer development and progression. Besides, they are differentially expressed in human tumor tissues. In the current study, we found that miR-320 was significantly downregulated in human osteosarcoma tissues, compared with adjacent normal tissues. Introduction of miR-320 mimics into U2OS and MG63 cells inhibited cell proliferation, while cell apoptosis rate remained unaltered. Additionally, miR-320 overexpression could also suppress tumor growth in the nude mice. At the molecular level, our results further revealed that the expression of fatty acid synthase (FASN), a key enzyme for de novo biosynthesis of fatty acids, was negatively regulated by miR-320. Therefore, our results suggest that miR-320 may act as a tumor suppressor for osteosarcoma.     

MicroRNA-16 Inhibits Bladder Cancer Proliferation by Targeting Cyclin D1

MicroRNA-16 (miR-16) has been demonstrated to regulate proliferation and apoptosis in many types ofcancers, but its biological function in bladder cancer remains unknown. Here, we found expression of miR-16 tobe downregulated in bladder cancer in comparison with the adjacent normal tissues. Enforced expression of miR-16 was able to inhibit cell proliferation in TCHu-1 cells, in line with results for miR-16 antisense oligonucleotides(antisense miR-16). At the molecular level, our results further revealed that cyclin D1 expression was negativelyregulated by miR-16. Therefore, the data reported here demonstrate that miR-16 is an important regulator inbladder cancer, which will contribute to better understanding of important mis-regulated miRNAs.     

miR-145 inhibits osteosarcoma cells proliferation and invasion by targeting ROCK1

MicroRNAs (miRNAs) contribute to the development and progression of various types of human cancers. The aim of this study was to study the role of miR-145 and to identify its functional target gene in osteosarcoma (OS) cells. We found that miR-145 was reduced in OS tissues and cell lines. Enforced expression of miR-145 inhibited cell proliferation, migration, and invasion abilities of MG-63 cells. Furthermore, we revealed that Rho-associated protein kinase 1 (ROCK1) was a target of miR-145 in OS. Finally, we found that silencing of ROCK1 performed similar effects with miR-145 in MG-63 cells, and ROCK1 was inversely correlated with miR-145 in OS tissues. Collectively, these data indicate that miR-145 may act as a tumor suppressor and contributes to the progression of OS through targeting ROCK1.     

Mir-150 Up-Regulates Glut1 and Increases Glycolysis in Osteosarcoma Cells

Objective: Osteosarcoma (OS) is the most common malignant bone tumor in children and young adults. Many studies have shown that microRNAs play a critical role in proliferation and metastasis with this tumour type. However, whether aberrant expression might contribute to a metabolism switch in osteosarcoma cases is not clearly understood. In this study, we explored expression and function of miR-150 in osteosarcoma cells. Materials and methods: Expression of miR-150 was assessed by real-time PCR in cell lines and human patient tissues. Scramble siRNA, miR-150 inhibitor, and miR-150 mimics were transfected into osteosarcoma cells to determine their effects on proliferation rate, glucose uptake and lactate secretion. Finally, the relationship between Glut1 and the miR-150 level was explored by luciferase reporter assay and western blotting. Result: miR-150 was consistently decreased in cell lines and osteosarcoma tissues as compared to osteoblast cells and normal bone. Ectopic overexpression of miR-150 inhibited osteosarcoma cell proliferation and suppressed glucose uptake and lactate secretion. Loss of function of miR-150, on the other hand, enhanced osteosarcoma cell proliferation and increased glucose uptake and lactate secretion. Western blot and luciferase reporter assays showed that miR-150 may function by regulating Glut1 expression. Conclusion: These data suggest that miR-150 is involved in regulation of glycolysis in osteosarcoma cells by influencing Glut1 expression.     

MiR-542-5p is a negative prognostic factor and promotes osteosarcoma tumorigenesis by targeting HUWE1

Recent evidence has demonstrated that microRNAs (miRNAs) are involved in the proliferation and metastasis of osteosarcoma. Using miRNA microarray and functional screening methods to compare miRNA expression profiles in osteosarcoma cell lines treated with Trichostatin A (TSA), overexpression of miR-542-5p was determined to be involved in the proliferation of osteosarcoma. We used isobaric tags for relative and absolute quantitation (iTRAQ) and nanoscale liquid chromatography-mass spectrometry (NanoLC−MS/MS) to identify differentially expressed proteins in MNNG/HOS and U2OS osteosarcoma cell lines transfected with miR-542-5p; in both cell lines, seven proteins were downregulated, and nine were upregulated. HUWE1 was found to be a direct target of miR-542-5p in both osteosarcoma cell lines, and was negatively correlated with miR-542-5p levels in human osteosarcoma tissues. Moreover, the expression of miR-542-5p was upregulated in human osteosarcoma tissue compared with non-tumor adjacent tissue. Kaplan-Meier analysis revealed that overexpression of miR-542-5p predicted poor prognosis for osteosarcoma patients. Taken together, our results indicated that miR-542-5p plays a critical role in the proliferation of osteosarcoma and targets HUWE1.     

miR-132 targeting cyclin E1 suppresses cell proliferation in osteosarcoma cells

In this study, we investigated the roles of miR-132 in tumor growth of osteosarcoma. We found that overexpression of miR-132 significantly suppressed in vitro cell proliferation and in vivo tumor growth. In addition, miR-132 overexpression induced G1/S cell cycle arrest of osteosarcoma cells. Further study showed that miR-132 could interact with the 3′-untranslated region of cyclin E1 (CCNE1) gene and repress its expression. Re-expression of CCNE1 (without the 3′UTR) could partially abrogate the miR-132-induced cell proliferation inhibition. Of significance, contrary to CCNE1, expression level of miR-132 was significantly lower in osteosarcoma tissues than in the adjacent normal tissues. Taken together, these results indicate that miR-132 functions as a tumor suppressor in osteosarcoma and that its suppressive effects are mediated chiefly by repressing CCNE1 expression.     

miRNA-218 Inhibits Osteosarcoma Cell Migration and Invasion by Down-regulating of TIAM1, MMP2 and MMP9

Deregulated miRNAs participate in osteosarcoma genesis. In this study, the expression of miRNA-218 inhuman osteosarcomas, adjacent normal tissues and Saos-2 human osteosarcoma cells was first assessed. Then theprecise role of miRNA-218 in osteosarcoma cells was investigated. Upon transfection with a miR-218 expressionvector, the proliferation of Saos-2 human osteosarcoma cells determined using the ATPlite assay was significantlysuppressed, whilw migration of Saos-2 cells detected by wound healing and invasion determined using transwellswere dramatically inhibited. Potential target genes of miR-218 were predicted and T-cell lymphoma invasionand metastasis 1 (TIAM1) and matrix metalloproteinase 2 (MMP2) and 9 (MMP9) were identified. This wasconfirmed by western blotting, which showed that miR-218 expression inhibited TIAM1, MMP2 and MMP9protein expression. Collectively, these data suggest that miR-218 acts as a tumor suppressor in osteosarcomasby down-regulating TIAM1, MMP2 and MMP9 expression.     

MicroRNA-1226-3p has a tumor-promoting role in osteosarcoma

Osteosarcoma is a malignant bone tumor that commonly occurs in young individuals. It accounts for 10% of solid tumors in those who are 15–19 years old. MicroRNA (miRNA/miR) dysregulation serves a crucial role in the molecular mechanism of osteosarcoma. The present study reported a novel miRNA (miR-1226-3p) and investigated its function in osteosarcoma. miR-1226-3p mimics and miR-1226-3p antisense oligonucleotides were transfected into human osteosarcoma SaOS-2 cells to alter miR-1226-3 expression, while the hFOB 1.19 cell line was used as the control. The apoptosis rate was analyzed using a dead cell apoptosis kit. TNF receptor-associated factor 3 (TRAF3) protein expression was assayed by western blotting. The results of bioinformatics and clinical specimen analyses revealed that higher expression levels of miR-1226-3p were associated with lower survival rates. Additionally, the results of experiments on cultured cells revealed that miR-1226-3p promoted the proliferation of SaOS-2 cells, while miR-1226-3p inhibition decreased cell proliferation and increased apoptosis. Furthermore, it was revealed that miR-1226-3p targeted TRAF3 in SaOS-2 cells. In conclusion, the present study suggested that miR-1226-3p promoted the proliferation of osteosarcoma cells.     

Clinical significance of miR-155 expression in breast cancer and effects of miR-155 ASO on cell viability and apoptosis

Accumulating evidence shows that mircroRNAs (miRNAs) play a vital role in tumorigenesis. miR-155 is one of the most multifunctional miRNAs whose overexpression has been found to be associated with different types of cancer including breast cancer. To further determine the potential involvement of miR-155 in breast cancer, we evaluated the expression levels of miR-155 by real-time PCR and correlated the results with clinicopathological features. Matched non-tumor and tumor tissues of 42 infiltrating ductal carcinomas and 3 infiltrating lobular carcinomas were analyzed for miR-155 expression by real-time PCR. Further, we used an antisense technique to inhibit miR-155 expression in vitro. WST-8 test was performed to evaluate cell viability and apoptosis assay was used to investigate the effect of the miR-155 antisense oligonucleotide (miR-155 ASO) on HS578T cell death. The expression levels of miR-155 were significantly higher in tumor tissues than the levels in matched non-tumor tissues (P<0.001). Up-regulated miR-155 expression was associated with lymph node positivity (P=0.034), higher proliferation index (Ki-67 >10%) (P=0.019) and advanced breast cancer TNM clinical stage (P=0.002). Interestingly, we next found that miR-155 expression levels had close relations with ER status (P=0.041) and PR status (P=0.029). Transfection efficiency detected by flow cytometry was higher than 70%, the WST-8 test showed that viability of HS578T cells was greatly reduced after transfection with miR-155 ASO compared with the scramble (SCR) group or the liposome group. The Annexin V-FITC/PI assay also indicated that transfection with miR-155 ASO promoted apoptosis.     

miR-199a-3p在乳腺癌中的表达及其作用

背景与目的：多种微小RNA(microRNA,miRNA)在乳腺癌中异常表达,在乳腺癌的发生、发展中起重要作用。miRNA可能是治疗乳腺癌的新靶点。该研究旨在探讨miR-199a-3p在乳腺癌中的表达水平,及其对乳腺癌癌细胞增殖和凋亡的影响。方法：运用实时定量聚合酶链式反应(quantitative real-time polymerase chain reaction,QRT-PCR)检测乳腺癌患者癌组织、癌旁正常组织、人乳腺癌细胞和人乳腺细胞中miRNA-199a-3p的表达水平,miR-199a-3p mimic(或inhibitor)转染乳腺癌细胞MDA-MB-231过表达(或沉默)miR-199a-3p的表达后,通过MTT法检测细胞增殖能力,Hoechst染色法和caspase-3活力测试检测细胞凋亡情况。结果：相对癌旁正常组织和人正常乳腺细胞,miR-199a-3p在乳腺癌患者癌组织和人乳腺癌细胞中表达下调。在MDA-MB-231中转染miR-199a-3p mimic过表达miR-199a-3p可抑制细胞增殖,促进其凋亡;在MDA-MB-231中转染miR-199a-3p inhibitor沉默miR-199a-3p可促进细胞增殖,抑制其凋亡。结论：miR-199a-3p在乳腺癌中表达下调,并通过调节乳腺癌细胞增殖和凋亡发挥抑癌作用。