The Impact Of UHRF1 On Invasion Of Osteosarcoma Cell And Its And Its Mechanism Of Regulation

Objective:1. To examine the effect of UHRF1 on the invasion of osteosarcoma cells.2. To explored the related mechanismsMethods:1.We examine the levels of UHRF1 in four human osteosarcoma cell lines MG-63, Saos-2, U2 OS and HOS. Then,we determine the effect of UHRF1 on the proliferation of human osteosarcoma cells by CCK-8 assay.2.In order to investigate the function of UHRF1 to the invasion of osteosarcoma cells, transwell invasion assays were used with human osteosarcoma cell lines in vitro.3.We first examined the expression levels of Rb1 in the osteosarcoma cell lines by Western blot. To further investigate the mechanism of UHRF1 to regulate the invasion of osteosarcoma cells, we stably knock-down the expression of Rb1 gene in MG-63 cells。4.We exmine the effect of overexpression of UHRF1 on the expression of Rb1 and E-cadherin in MG-63 and U2 OS cells.5.We exmine the effect of overexpression of UHRF1 on EMT.Results:1.We found the expression of UHRF1 was detectable in all of the cell lines. And UHRF1 overexpression increases cells proliferation.2.UHRF1 promotes the invasion of MG-63 and U2 OS human osteosarcoma cells but not Saos-2 cells with homozygous deletion of Rb13.Overexpression of UHRF1 could not affect the invasion in Rb1 stably knock-down MG-63 cells4.UHRF1 inhibited the expression of E-cadherin through the repression of Rb1.5.UHRF1 promoted epithelial-mesenchymal transition of Rb1 positve cells.Conclusion:1. UHRF1 increases the cell proliferation/invasion and promoted epithelial-mesenchymal transition in osteosarcoma cells.2. UHRF1 promotes osteosarcoma cells invasion in Rb1-dependent manner.3. UHRF1 promotes osteosarcoma cells invasion by down-regulating E-cadherin and increasing EMT in Rb1-dependent manner.MTX and docetaxel is thought as useful for osteosarcoma in past research. But chemoresistance is main obstacle to hampering efficacy of chemotherapy. Here, we tested the anti-apoptosis pathway in U2 OS and MG63 cell lines. CXCL12 was found to down-regulate dramatically in progression of chemoresistance in U2 OS and MG63. We found down-regulation of Bcl-xl was induced in anti-apoptosis pathway.Objective:1.To examine the effect of CXCL12 in chemoresistance of osteosarcoma.2.To explored the related mechanisms.Methods:1.To obtain the cell line which could represent progressive chemoresistance in vitro.2. In order to investigate causes which lead to anti-apoptosis. RNA assay was applied to explore genomics of U2OS-MTX, U2OS-Docetaxel, MG63-MTX and MG63-Docetaxel cell line in vitro.3.To determine whether Bcl-2, Bcl-xl, Noxa and Bax involved in chemoresistant pathway.Results:1.We got the cell line which could represent progressive chemoresistance.2.CXCL12 is the crossing spot in assay with enormous difference in RNA assay.3.We found Bcl-xl decreased enormously in all cell lines in contrast with parent cell lines.Conclusions:1. CXCL12 take a pivotal role in chemoresistance of osteosarcoma2. We found down-regulation of Bcl-xl was induced in anti-apoptosis pathway.