PAI-1, a target gene of miR-143, regulates invasion and metastasis by upregulating MMP-13 expression of human osteosarcoma.
ABSTRACT: Despite recent improvements in the therapy for osteosarcoma, 30-40% of osteosarcoma patients die of this disease, mainly due to its lung metastasis. We have previously reported that intravenous injection of miR-143 significantly suppresses lung metastasis of human osteosarcoma cells (143B) in a mouse model. In this study, we examined the biological role and mechanism of miR-143 in the metastasis of human osteosarcoma cells. We identified plasminogen activator inhibitor-1 (PAI-1) as a direct target gene of miR-143. To determine the role of PAI-1 in human osteosarcoma cells, siRNA was transfected into 143B cells for knockdown of PAI-1 expression. An in vitro study showed that downregulation of PAI-1 suppressed cell invasion activity, but not proliferation. Moreover, injection of PAI-1 siRNA into a primary lesion in the osteosarcoma mouse model inhibited lung metastasis compared to control siRNA-injected mice, without influencing the proliferative activity of the tumor cells. Subsequent examination using 143B cells revealed that knockdown of PAI-1 expression resulted in downregulation of the expression and secretion of matrix metalloproteinase-13 (MMP-13), which is also a target gene of miR-143 and a proteolytic enzyme that regulates tumor-induced osteolysis. Immunohistochemical analysis using clinical samples showed that higher miR-143 expressing cases showed poor expression of PAI-1 in the primary tumor cells. All such cases belonged to the lung metastasis-negative group. Moreover, the frequency of lung metastasis-positive cases was significantly higher in PAI-1 and MMP-13 double-positive cases than in PAI-1 or MMP-13 single-positive or double-negative cases (P < 0.05). These results indicated that PAI-1, a target gene of miR-143, regulates invasion and lung metastasis via enhancement of MMP-13 expression and secretion in human osteosarcoma cells, suggesting that these molecules could be potential therapeutic target genes for preventing lung metastasis in osteosarcoma patients.
Project description:Pulmonary metastases are the main cause of death in patients with osteosarcoma, however, the molecular mechanisms of metastasis are not well understood. To detect lung metastasis-related microRNA (miRNA) in human osteosarcoma, we compared parental (HOS) and its subclone (143B) human osteosarcoma cell lines showing lung metastasis in a mouse model. miR-143 was the most downregulated miRNA (P < 0.01), and transfection of miR-143 into 143B significantly decreased its invasiveness, but not cell proliferation. Noninvasive optical imaging technologies revealed that intravenous injection of miR-143, but not negative control miRNA, significantly suppressed lung metastasis of 143B (P < 0.01). To search for miR-143 target mRNA in 143B, microarray analyses were performed using an independent RNA pool extracted by two different comprehensive miR-143-target mRNA collecting systems. Western blot analyses revealed that MMP-13 was mostly protein downregulated by miR-143. Immunohistochemistry using clinical samples clearly revealed MMP-13-positive cells in lung metastasis-positive cases, but not in at least three cases showing higher miR-143 expression in the no metastasis group. Taken together, these data indicated that the downregulation of miR-143 correlates with the lung metastasis of human osteosarcoma cells by promoting cellular invasion, probably via MMP-13 upregulation, suggesting that miRNA could be used to develop new molecular targets for osteosarcoma metastasis.
Project description:Lung metastasis constitutes the leading cause of the death in patients with osteosarcoma. We have previously reported that plasminogen activator inhibitor-1 (PAI-1) regulates the invasion and lung metastasis of osteosarcoma cells in a mouse model and as well as in clinical samples. In the present study, we examined the anti-metastatic effect of SK-216, a small compound PAI-1 inhibitor, in human 143B osteosarcoma cells. An in vitro study showed that SK-216 treatment suppressed invasion activity by inhibiting PAI-1 expression in 143B cells, but had no influence on their proliferation or migration. 143B cells treated with SK-216 exhibited reduced matrix metalloproteinase-13 (MMP-13) secretion in a dose-dependent manner. Moreover, intraperitoneal injection of SK-216 into mouse models resulted in downregulation of PAI-1 expression levels in the primary tumors and showed suppression of lung metastases without influencing the proliferative activity of the tumor cells in the primary lesions. These results indicate that SK-216, a PAI-1 inhibitor, may serve as a novel drug to prevent lung metastasis in human osteosarcoma.
Project description:More effective treatment of metastasizing osteosarcoma with a current mean 5-year survival rate of less than 20% requires more detailed knowledge on mechanisms and key regulatory molecules of the complex metastatic process. CXCR4, the receptor of the chemokine CXCL12, has been reported to promote tumor progression and metastasis in osteosarcoma. CXCR7 is a recently deorphanized CXCL12-scavenging receptor with so far not well-defined functions in tumor biology. The present study focused on a potential malignancy enhancing function of CXCR7 in interaction with CXCR4 in osteosarcoma, which was investigated in an intratibial osteosarcoma model in SCID mice, making use of the human 143B osteosarcoma cell line that spontaneously metastasizes to the lung and expresses endogenous CXCR4. 143B osteosarcoma cells stably expressing LacZ (143B-LacZ cells) were retrovirally transduced with a gene encoding HA-tagged CXCR7 (143B-LacZ-X7-HA cells). 143B-LacZ-X7-HA cells co-expressing CXCR7 and CXCR4 exhibited CXCL12 scavenging and enhanced adhesion to IL-1?-activated HUVEC cells compared to 143B-LacZ cells expressing CXCR4 alone. SCID mice intratibially injected with 143B-LacZ-X7-HA cells had significantly (p<0.05) smaller primary tumors, but significantly (p<0.05) higher numbers of lung metastases than mice injected with 143B-LacZ cells. Unexpectedly, 143B-LacZ-X7-HA cells, unlike 143B-LacZ cells, also metastasized with high incidence to the auriculum cordis. In conclusion, expression of the CXCL12 scavenging receptor CXCR7 in the CXCR4-expressing human 143B osteosarcoma cell line enhances its metastatic activity in intratibial primary tumors in SCID mice that predominantly metastasize to the lung and thereby closely mimic the human disease. These findings point to CXCR7 as a target, complementary to previously proposed CXCR4, for more effective metastasis-suppressive treatment in osteosarcoma.
Project description:Osteosarcoma is the most common primary malignant bone tumour. Patients often develop lung metastasis and have a poor prognosis despite extensive chemotherapy and surgical resections. Tissue Factor is associated with poor clinical outcome in a wide range of cancer types, and promotes angiogenesis and metastasis. The role of Tissue Factor in OS tumourigenesis is unknown. Fifty-three osteosarcoma pre-treatment biopsies and four osteosarcoma cell lines were evaluated for Tissue Factor expression, and a possible association with clinical parameters was investigated. Tissue Factor function was inhibited in an osteosarcoma cell line (143B) by shRNA knockdown or specific antibodies, and pro-tumourigenic gene expression, proliferation, matrigel invasion and transwell migration was examined. 143B cells were implanted in mice in the presence of Tissue Factor-blocking antibodies, and tumour volume, micro-vessel density and metastases in the lung were evaluated. Tissue Factor was highly expressed in 73.6?% of osteosarcoma biopsies, and expression associated significantly with disease-free survival. Tissue Factor was expressed in all four investigated cell lines. Tissue Factor was knocked down in 143B cells, which led to reduced expression of IL-8, CXCL-1, SNAIL and MMP2, but not MMP9. Tissue Factor knockdown or inhibition with antibodies reduced matrigel invasion. Tissue Factor antibodies limited 143B tumour growth in vivo, and resulted in decreased intra-tumoural micro-vessel density. Furthermore, lung metastasis from the primary tumour was significantly reduced. Thus, Tissue Factor expression in osteosarcoma reduces metastasis-free survival in patients, and increases pro-tumourigenic behaviour both in vitro and in vivo.
Project description:The plant extract piperine is used as a traditional Chinese medicine due to its anti?inflammatory effects and efficacy against numerous types of cancer. The aim of the present study was to investigate the antitumor mechanism of piperine in human osteosarcoma U2OS and 143B cell lines. The effects of piperine on cell apoptosis and invasion of human osteosarcoma cells were assessed using flow cytometry and Transwell assays. Moreover, western blotting was used to measure the effects of piperine on the protein expression levels of the metastasis markers matrix metalloproteinase?2 (MMP?2) and vascular endothelial growth factor (VEGF). In addition, the involvement of the Wnt/??catenin signaling pathway in modulating the effects of piperine was examined via western blot analysis. The results of MTT and Transwell invasion assays indicated that piperine treatment dose?dependently reduced U2OS and 143B cell viability and invasion. Furthermore, a significant reduction was identified in MMP?2, VEGF, glycogen synthase kinase?3? and ??catenin protein expression levels, as well as the expression levels of their target proteins cyclooxygenase?2, cyclin D1 and c?myc, in U2OS cells after piperine treatment. In addition, similar results were observed in 143B cells. Therefore, the present study demonstrated the efficacy of piperine in osteosarcoma, and identified that the Wnt/??catenin signaling pathway may modulate the antitumor effects of piperine on human U2OS and 143B cells.
Project description:Osteosarcomas, the most common malignant bone tumors, show a potent capacity for local invasion and pulmonary metastasis. Resveratrol (RESV), a phytochemical, exhibits multiple tumor-suppressing activities and has been tested in clinical trials. However, the antitumor activities of RESV in osteosarcomas are not yet completely defined. In osteosarcoma cells, we found that RESV inhibited the migration/invasion in vitro and lung metastasis in vivo by suppressing matrix metalloproteinase (MMP)-2. We identified that RESV exhibited a transcriptional inhibitory effect on MMP-2 through reducing CREB-DNA-binding activity. Moreover, a microRNA (miR) analysis showed that miR-328 was predominantly upregulated after RESV treatment. Inhibition of miR-328 significantly relieved MMP-2 and motility suppression imposed by RESV treatment. Furthermore, ectopic miR-328 expression in highly invasive cells decreased MMP-2 expression and invasive abilities. Mechanistic investigations found that JNK and p38 MAPK signaling pathways were involved in RESV-regulated CREB-DNA-binding activity, miR328 expression, and cell motility. Clinical samples indicated inverse expression between MMP-2 and miR-328 in normal bone and osteosarcoma tissues. The inverse correlation of MMP-2 and miR-328 was also observed in tumor specimens, and MMP-2 expression was linked to tumor metastasis. Taken together, our results provide new insights into the role of RESV-induced molecular and epigenetic regulation in suppressing tumor metastasis.
Project description:Osteosarcoma, the most common primary malignant bone tumor, shows potent capacity for local invasion and distant metastasis. Connective tissue growth factor (CTGF/CCN2), a secreted protein, binds to integrins, modulates invasive behavior of certain human cancer cells. Effect of CTGF in metastasis of human osteosarcoma is unknown. We found overexpression of CTGF increasing matrix metalloproteinases (MMPs)-2 and MMP-3 expression as well as promoting cell migration. MicroRNA (miRNA) analysis of CTGF-overexpressed osteosarcoma versus control cells probed mechanisms of CTGF-mediated promotion of migration. Among miRNAs regulated by CTGF, miR-519d was most downregulated after CTGF treatment. Co-transfection with miR-519d mimic reversed CTGF-mediated MMPs expression and cell migration. Also, MEK and ERK inhibitors or mutants reduced CTGF-increased cell migration and miR-519d suppression. By contrast, knockdown of CTGF diminished lung metastasis in vivo. Clinical samples indicate CTGF expression as linked with clinical stage and tumor metastasis. Taken together, data show CTGF elevating MMPs expression and subsequently promoting tumor metastasis in human osteosarcoma, down-regulating miR-519d via MEK and ERK pathways, making CTGF a new molecular therapeutic target in osteosarcoma metastasis.
Project description:Osteosarcoma is the most common primary bone tumor during childhood and adolescence. Several reports have presented data on serum biomarkers for osteosarcoma, but few reports have analyzed circulating microRNAs (miRNAs). In this study, we used next generation miRNA sequencing to examine miRNAs isolated from microvesicle-depleted extracellular vesicles (EVs) derived from six different human osteosarcoma or osteoblastic cell lines with different degrees of metastatic potential (i.e., SAOS2, MG63, HOS, 143B, U2OS and hFOB1.19). EVs from each cell line contain on average ~300 miRNAs, and ~70 of these miRNAs are present at very high levels (i.e., >1000 reads per million). The most prominent miRNAs are miR-21-5p, miR-143-3p, miR-148a-3p and 181a-5p, which are enriched between 3 and 100 fold and relatively abundant in EVs derived from metastatic SAOS2 cells compared to non-metastatic MG63 cells. Gene ontology analysis of predicted targets reveals that miRNAs present in EVs may regulate the metastatic potential of osteosarcoma cell lines by potentially inhibiting a network of genes (e.g., MAPK1, NRAS, FRS2, PRCKE, BCL2 and QKI) involved in apoptosis and/or cell adhesion. Our data indicate that osteosarcoma cell lines may selectively package miRNAs as molecular cargo of EVs that could function as paracrine agents to modulate the tumor micro-environment.
Project description:Osteosarcoma (OS) is the most common primary pediatric malignancy of the bone having poor prognosis and long-term survival rates of less than 30% in patients with metastasis. MicroRNA-509 was reported to be downregulated in OS. We and others previously published that miR-509-3p can strongly attenuate cellular migration/invasion and sensitize ovarian cancer to cisplatin. Here, we show that overexpression of miR-509-3p inhibited migration of primary OS cell lines U2OS, HOS, and SaOS2 as well as metastatic derivatives 143B and LM7. miR-509-3p overexpression also inhibited proliferation and invasion of HOS and 143B cells and sensitized cells to cisplatin. Luciferase reporter assays using 3'-UTRs of predicted miR-509-3p targets associated with metastatic phenotypes revealed ARHGAP1 could be one of the downstream effectors of miR-509-3p in HOS. To find the global impact of miR-509-3p overexpression and cisplatin treatment we performed Reverse Phase Protein Analysis (RPPA). AXL, which has been reported to play a critical role in cisplatin resistance and confirmed as direct target of miR-509-3p was downregulated upon miR-509-3p treatment and further down-regulated upon miR-509-3p + cisplatin treatment. We propose that the miR-509-3p/AXL and miR-509-3p/ARHGAP1 axes have the potential to uncover new druggable targets for the treatment of drug resistant metastatic osteosarcoma.
Project description:The membrane-anchored matrix metalloprotease MT1-MMP is a potent collagenolytic enzyme with a well-established role in extracellular matrix turnover and cellular invasion into collagen-rich tissues. MT1-MMP is highly expressed in various types of cancer and has been demonstrated to be directly involved in several stages of tumor progression, including primary tumor growth, angiogenesis, invasion and metastasis. Osteosarcoma is the most common type of primary bone cancer. This disease is characterized by invasive tumor growth, leading to extensive bone destruction, and metastasis to the lungs. The tumor cells in human osteosarcoma display a strong expression of MT1-MMP, but the role of MT1-MMP in osteosarcoma progression is currently unknown. In this study, we investigated the role of MT1-MMP during various stages of osteosarcoma development. We utilized an optimized orthotopic murine osteosarcoma model and human osteosarcoma cells in which the MT1-MMP gene was knocked out using CRISPR/Cas9. We observed a strong expression of MT1-MMP in wildtype cells of both primary tumors and lung metastases, but, surprisingly, MT1-MMP deficiency did not affect primary tumor growth, bone degradation or the formation and growth of lung metastases. We therefore propose that, unlike findings reported in other cancers, tumor-expressed MT1-MMP is dispensable for all stages of osteosarcoma progression.