| Malignancy is one of the serious diseases that do great harm to health. With the development of modern medical science, there are some means to deal with it, such as surgical treatment, and adjuvant chemotherapy, radiotherapy and immunotherapy. Some encouraging results have been obtained from all of these therapy, but it is very limited, and far from cure. For example, it is still an unsolved problem to prevent the tumor cells from metastasis. In clinic, metastasis of a tumor means the failure of treatment for majority of cases. And there is not an efficient method to diagnosis metastasis in early stage. Therefore, many researches focused on the molecular mechanism of tumor metastasis, and try to develop methods of diagnosis and treatment.Osteosarcoma is the most common primary malignant tumor of bone. It is very difficult to treat it with the current therapeutic methods. About 20-30% patients died of early metastasis. To study the genes associated with genesis and progression of osteosarcoma will be helpful to understand the molecular mechanism of tumor metastasis.Two cell lines named SOSP-9607 and SOSP-M were cultured and their total RNA were extracted by Trizol respectively. The first strand of cDNA was reversely transcripted from RNA. The cDNA of SOSP-9607 was labeled by Cy3-dUTP, and the cDNA of SOSP-M was labeled by Cy5-dUTP. The cDNAs were dissoluted in 5 SSC+0.2% SDS respectively after precipitation of ethanol. After 5 minutes incubation at 95 , the labeled probes were applied onto the cDNA microarray. The slides were covered, and then put in an airproof cabin at 60 for 15-17 hours. After hybridization the slides were uncovered, washed by 2 SSC+0.2% SDS, 0.1% SSC+0.2% SDS, 0.1% SSC orderly, and then given an airing.The cDNA microarray was scanned by ScanArray 3000 to obtain the fluorescence signal intensity of genes expression. The original signals wereequipoised and modified according to inner contrasts, and then analyzed by software ImaGene 3.0. The Cy5/Cy3 ratio of all genes on microarray was calculated from standardized data. There were 101 data which ratio>2.0 or <0.5, and there were 22 data represented 11 genes differentially expressed among them. Some genes related to metastasis were preliminarily scanned, which would contribute to disclose the molecular mechanism of metastasis and provide new targets for therapeutic intervention. It suggested that there are many genes differentially expressed on various extent, some are associated with cell growth and differentiation, cell cycle and signal transduction.Some ASODNs were designed based on screen results of microarrayn and applied to study the relation of gene expression and cell growth in vitro. It showed that the cell growth of SOSP-9607 could be enhanced by BRCAl-ASODNs or by BLCAP-ASODNs. There was prominent difference since the 4th day of test.Compared with colony formation of control group (51 5), the colony formation of BRCAl-ASODNs (85 8) was prominently increased, and the colony formation of BLCAP-ASODNs (90 7) was prominently increased too. There is no prominently difference between BRCAl-ASODNs and BLCAP-ASODNs groups.Compared with control group, the ratio of PI and S were up-regulated, and the cell proliferation activity of test group was improved. It seemed that the ASODNs of the two genes have similar effects on cell proliferation.The result of SABC staining showed that the BRCA1 protein located in plasm of osteosarcoma cell, and the expression of the protein was down-regulated on the effect of BRCAl-ASODNs.The BLCAP gene was found by Denmark scientists when they studied highly invasive bladder cancer. It coded a 10KD protein with its function unknown. The pilot study indicated that it was associated with tumor invasive, might be a new tumor suppressor gene. In our screen of metastasis associatedgenes of osteosarcoma, the BLCAP gene was found expressed in osteosarcoma, and its expression in metastasis tumor was much lower than that in primary tumor. Then we planned to clone the new gene to stu...
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