| Objective:Giant cell tumor of bone(GCTB)is one of the common primary tumors,the pathogenesis is not clear,and the recurrence rate is high.A large number of studies have confirmed that RANK/RANKL/OPG signal pathway plays an important role in osteolytic destruction of GCTB,and MicroRNA-217 may participate in the occurrence and development of GCTB by regulating this signal pathway,but the exact regulation mechanism is not clear.In this study,Patient-Derived tumor Xenograft(PDX)model was used to explore the relationship between MicroRNA-217 and the occurrence and development of GCTB,and its effect on RANK/RANKL/OPG signal pathway in subcutaneous tumors.Method:After the giant cell tumor cells of bone were cultured in vitro,the GCTB cell lines stably overexpressing and interfering with miR-217 were transplanted into nude mice subcutaneously by PDX model to form subcutaneous nodules in nude mice.Thirty 8-week-old nude mice were randomly divided into 6 groups with 5 mice in each group.5×106 GCTB cells(100μL/mouse)cultured in vitro were inoculated subcutaneously in the right armpit.The nude mice were normally raised for 6 weeks.The growth of subcutaneous tumors in each group was observed,the volume and weight of subcutaneous tumors were measured,and the effects of different expression of miR-217 on the growth,volume and weight of subcutaneous tumors in nude mice were analyzed.The expression of OPG,RANK and RANKL in subcutaneous tumors was detected by immunohistochemistry,quantitative PCR and Western blot,and the effect of miR-217 on the expression of RANK/RANKL/OPG signal pathway in subcutaneous tumors was analyzed.The data of each group were analyzed by statistical method,and whether the difference between each group at each time point was statistically significant.Results:(1)the growth of subcutaneous tumor was slower in miR-217 mimics group and faster in miR-217 inhibitor group.(2)the subcutaneous nodulation volume and weight of nude mice in miR-217 mimics group were significantly lower than those in control group and NC group,while those in miR-217 inhibitor group were significantly higher than those in control group and NC group.(3)Immunohistochemical results:the protein expression of OPG and RANK was significantly decreased and the protein expression of RANKL was significantly increased in miR-217 mimic group,while the protein expression of OPG and RANK was significantly increased and the protein expression of RANKL was significantly decreased in miR-217 inhibitor group.(4)quantitative PCR results:the mRNA expression level of OPG was significantly decreased and the mRNA expression level of RANKL was significantly increased in miR-217 mimic group.In miR-217inhibitor group,the mRNA expression level of OPG was significantly increased,while the mRNA expression level of RANKL was significantly decreased.(5)Western blot results:in miR-217 mimic group,the protein expression level of OPG and RANK was significantly decreased,while the protein expression level of RANKL was significantly increased.In miR-217 inhibitor group,the protein expression levels of OPG and RANK were significantly increased,while the protein expression levels of RANKL were significantly decreased.Conclusions:(1)there is a certain relationship between miR-217 and the occurrence and development of GCTB.Overexpression of miR-217 can delay the growth of GCTB and inhibit the volume and weight of subcutaneous tumor in nude mice.(2)RANK/RANKL/OPG signal pathway is involved in the growth of subcutaneous tumor in GCTB nude mice.The high expression of OPG protein and mRNA may promote the growth of subcutaneous tumor.The low expression of RANKL protein and mRNA may promote the growth of subcutaneous tumor.(3)in the process of subcutaneous nodulation in GCTB nude mice,MicroRNA-217 can regulate RANK/RANKL/OPG signal pathway and change the expression of related proteins and mRNA,so as to delay tumor growth and prevent tumor recurrence. |
