Project description:SaOS2 osteosarcoma cells were cultured with or without atorvastatin (10 µM) for 6, 15 or 24h (2 biological replcates). RNA were isolated and hybridized to RNG microarrays. Background Osteosarcoma is the most common primary tumor of bone. The rapid development of metastatic lesions and resistance to chemotherapy remain major mechanisms responsible for the failure of treatments and poor survival rate for patients. Methods We previously showed that the HMGCoA reductase inhibitors statins exhibit anti-tumoral effects on osteosarcoma cells. Here, using microarray analysis, we identify cyr61/CCN1 as a new target of statins. Modulations of expression of cyr61 were performed in human and murine osteosarcoma cell lines to investigate in vitro cell viability, migratory potential and invasiveness. Cyr61 expression was evaluated in 231 tissue cores from osteosarcoma patients using tissue microarray. Tumor behavior and metastases occurence were analysed by IM injection of modified osteosarcoma cells to BALB/c mice. Results Transcriptome comparisons revealed that statins down-regulate cyr61 expression in SaOS2 cells. Cyr61 silencing in human and murine osteosarcoma cell lines enhanced cell death, but reduced cell migration and cell invasion compared to parental cells whereas cyr61 overexpression had opposite effects. Tissue microarray analysis demonstrated that cyr61 protein expression is higher in human osteosarcoma compared to normal bone tissue and is further increased in metastatic tissues. In vivo, cyr61 overexpression in osteosarcoma cells enhanced lung metastases development whereas cyr61 silencing strongly reduced metastases in mice. Conclusion The results reveal that cyr61 expression increases with tumor grade in human osteosarcoma and demonstrate that cyr61 silencing inhibits in vitro osteosarcoma cell invasion and migration as well as in vivo lung metastases in mice. These data provide a novel molecular target for therapeutic intervention in metastatic osteosarcoma.
Project description:SaOS2 osteosarcoma cells were cultured with or without atorvastatin (10 µM) for 6, 15 or 24h (2 biological replcates). RNA were isolated and hybridized to RNG microarrays. Background Osteosarcoma is the most common primary tumor of bone. The rapid development of metastatic lesions and resistance to chemotherapy remain major mechanisms responsible for the failure of treatments and poor survival rate for patients. Methods We previously showed that the HMGCoA reductase inhibitors statins exhibit anti-tumoral effects on osteosarcoma cells. Here, using microarray analysis, we identify cyr61/CCN1 as a new target of statins. Modulations of expression of cyr61 were performed in human and murine osteosarcoma cell lines to investigate in vitro cell viability, migratory potential and invasiveness. Cyr61 expression was evaluated in 231 tissue cores from osteosarcoma patients using tissue microarray. Tumor behavior and metastases occurence were analysed by IM injection of modified osteosarcoma cells to BALB/c mice. Results Transcriptome comparisons revealed that statins down-regulate cyr61 expression in SaOS2 cells. Cyr61 silencing in human and murine osteosarcoma cell lines enhanced cell death, but reduced cell migration and cell invasion compared to parental cells whereas cyr61 overexpression had opposite effects. Tissue microarray analysis demonstrated that cyr61 protein expression is higher in human osteosarcoma compared to normal bone tissue and is further increased in metastatic tissues. In vivo, cyr61 overexpression in osteosarcoma cells enhanced lung metastases development whereas cyr61 silencing strongly reduced metastases in mice. Conclusion The results reveal that cyr61 expression increases with tumor grade in human osteosarcoma and demonstrate that cyr61 silencing inhibits in vitro osteosarcoma cell invasion and migration as well as in vivo lung metastases in mice. These data provide a novel molecular target for therapeutic intervention in metastatic osteosarcoma. Dye balance-experiment comparing atorvastatin versus untreated cells at 6, 15 and 24 hours using 2 biological replicates.
Project description:Ror2 is a member of the Ror-family of receptor tyrosine kinases acting as a receptor for Wnt5a. Wnt5a/Ror2 signaling activates primarily the ß-catenin-independent pathway, which involves various signal mediators, such as Dishevelled, c-Jun N-terminal kinase (JNK), filamin A, c-Src, and Ca2+. Wnt5a/Ror2 signaling has also been shown to inhibit the ß-catenin-dependent pathway. Wnt5a and Ror2 are overexpressed in various types of tumor cells, including osteosarcoma and melanoma cells, resulting in constitutive activation of Wnt5a/Ror2 signaling in a cell-autonomous manner. Constitutively activated Wnt5a/Ror2 signaling has been shown to play important roles in promoting invadopodia formation and invasiveness of tumor cells. However, little is known about the mechanisms underlying these processes. As an attempt to understand the mechanism by which Wnt5a/Ror2 signaling, activated constitutively in osteosarcoma cells, contributes to their highly invasive properties, we performed DNA microarray analysis using a human osteosarcoma cell line, SaOS2.
Project description:Osteoblasts represent an important cell type playing a role in not only bone formation but also regulate hematopoiesis by secreting factor as well as via contact with hematopoietic stem cells in the bone marrow. Since Wnt signalling plays an important role in osteoblast differentiation, we were interested in looking at how canonical Wnt signalling activation in osteoblastic cells is likely to affect hematopoietic cell adhesion and regulate their fate. Endogenous Wnt signaling activation in osteoblastic SaOS2 cells was achieved by generating doxycycline (DOX) inducible antisense-APC expressing SaOS2 cells. Gene expression profiling was performed on SaOS2 cells induced with DOX (1μg/ml) for 3 days and further on DOX treated cells allowed to recover for 3 days. The results reveal changes in expression of a number of cell adhesion and extracellular matrix protein genes as well as genes involved in osteoblast differentiation.
Project description:RNA was extracted from SaOS2 cells harboring a tet-inducible p21 expression vector. 3 replicates from untreated and 3 replicates from 24h doxycycline-treated cells.
Project description:Osteoblasts represent an important cell type playing a role in not only bone formation but also regulate hematopoiesis by secreting factor as well as via contact with hematopoietic stem cells in the bone marrow. Since Wnt signalling plays an important role in osteoblast differentiation, we were interested in looking at how canonical Wnt signalling activation in osteoblastic cells is likely to affect hematopoietic cell adhesion and regulate their fate. Endogenous Wnt signaling activation in osteoblastic SaOS2 cells was achieved by generating doxycycline (DOX) inducible antisense-APC expressing SaOS2 cells. Gene expression profiling was performed on SaOS2 cells induced with DOX (1μg/ml) for 3 days and further on DOX treated cells allowed to recover for 3 days. The results reveal changes in expression of a number of cell adhesion and extracellular matrix protein genes as well as genes involved in osteoblast differentiation. Doxycycline inducible antisense APC expressing SaOS2 cells were treated with DOX for 3 days and compared with control (untreated) cells. In addition, a set of DOX induced cells was further cultured for 3 days in absence of Dox to allow for the cells to recover and see the change in gene expression compared to Dox treated and control cells. All experiments were done in triplicates (in total 9 samples).