The Experimental Study On The Effectand The Mechanism Of RCN1 Onosteosarcoma Cell In Vivo And In Vitro

[Background and Objective]Osteosarcoma(OSA)is the most common primary malignant tumor of the bone in humans,accounting for about 30% of all malignant tumors of the skeletal system.The five-year survival rate of patients without metastasis is 75-77%.However,the metastasis of OSA usually happens at an early stage,in which the lung is the most common site.The 5-year survival rate of the patients with metastasis is only 20%.Moreover,there was little development in the treatment of osteosarcoma in recent decades.By analyzing the database of patients with osteosarcoma,we found that the overall survival rate of patients with high reticulocalbin-1(RCN1)expression was significantly lower than those with low RCN1 expression.The purpose of this study was to explore the mechanism of RCN1 in the development of osteosarcoma and explore a new treatment method for osteosarcoma.[Methods]By integrating and analyzing the database of osteosarcoma patients,we found the relationship of the overall survival rate of OSA patients and the expression level of RCN1.To further investigate the role of RCN1 in osteosarcoma,we cultured osteosarcoma cell lines(MG63,HOS,U2 OS and 143 B were all from ATCC)in vitro and transfected them with lentivirus to reduce their expression of RCN1.By clone formation experiment,we determined the effect of RCN1 on the proliferation of osteosarcoma cells.By transwell invasion and metastasis assay,we determined the effect of RCN1 on the migration and invasion ability of osteosarcoma cells in vitro.By WB and Q-pcr,we determined the effect of RCN1 on the expression of EMT pathway in osteosarcoma in vitro.By flow cytometry,we studied the effect of RCN1 on the apoptosis of osteosarcoma cells with different treatments.The effects of RCN1 on proliferation,invasion and metastasis ability of tumor cells in vivo were studied by subcutaneous tumor implantation and intravenous injection of tumor cells.[Results]The cloning experiment showed that RCN1 could promote the proliferation of osteosarcoma cells in vitro.Transwell invasion and metastasis experiment showed that RCN1 could promote the invasion and metastasis ability of osteosarcoma cells in vitro.Q-pcr and WB assay showed that RCN1 enhanced the expression of EMT pathway in osteosarcoma cells.Flow cytometry experiments showed that RCN1 inhibits the lethality of cisplatin on osteosarcoma cells.Animal studies show RCN1 promotes the proliferation and metastasis ability of osteosarcoma in vivo.[Conclusions]The database of osteosarcoma patients showed a negative correlation between RCN1 expression and prognosis.We found that RCN1 can promote the proliferation and invasion ability of OSA cell in vivo and vitro.Morever,the expression of RCN1 maybe relates to cisplatin resistance in osteosarcoma patients and the mechanism of drug resistance is still unclear.This is the primary task of our following experiment.