RESUMO
Objective To investigate the effects of knockdown of miR-449a on breast cancer xenograft in nude mice.Methods In this study,we established a model of breast cancer xenograft in nude mice with breast cancer MCF-7 cell line,then stably transfected MCF-7 cells with plasmids containing shRNA-miR-449a precursors;the stable transfected cells were injected subcutaneously into the nude mice by multi-point injection.We used negative plasmid as negative control and PBS as blank control.We detected tumor volume after the treatment of nude mice and tumor growth inhibition rate was calculated.The expressions of miR-449a and Notch1 in xenograft in nude mice were detected by real-time PCR;the levels of Notch 1,β-catenin and E-cadherin in the xenograft tumor tissues were detected by Western blot; and the expression of E-cadherin in tumor tissues was detected by immunohistochemistry.Results In the process of xenograft tumor formation,no nude mice died.Knockdown of miR-449a could significantly inhibit the growth of tumor volume after tumor detection (P <0.05 ).miR-449a was significantly down-regulated in xenograft tumor tissues,and the expressions of Notch 1 and β-catenin were also down-regulated,while the level of E-cadherin was increased.The results of immunohistochemistry showed that the expression of Notch1 protein was decreased and that of E-cadherin protein was increased (P <0.05).Conclusion Knockdown of miR-449a inhibited the normal growth of breast cancer xenografts in nude mice by down-regulating the expressions of Notch 1 andβ-catenin and promoting the expression of E-cadherin.
RESUMO
Objective To investigate the effects of knockdown of miR-449a on breast cancer xenograft in nude mice.Methods In this study,we established a model of breast cancer xenograft in nude mice with breast cancer MCF-7 cell line,then stably transfected MCF-7 cells with plasmids containing shRNA-miR-449a precursors;the stable transfected cells were injected subcutaneously into the nude mice by multi-point injection.We used negative plasmid as negative control and PBS as blank control.We detected tumor volume after the treatment of nude mice and tumor growth inhibition rate was calculated.The expressions of miR-449a and Notch1 in xenograft in nude mice were detected by real-time PCR;the levels of Notch 1,β-catenin and E-cadherin in the xenograft tumor tissues were detected by Western blot; and the expression of E-cadherin in tumor tissues was detected by immunohistochemistry.Results In the process of xenograft tumor formation,no nude mice died.Knockdown of miR-449a could significantly inhibit the growth of tumor volume after tumor detection (P <0.05 ).miR-449a was significantly down-regulated in xenograft tumor tissues,and the expressions of Notch 1 and β-catenin were also down-regulated,while the level of E-cadherin was increased.The results of immunohistochemistry showed that the expression of Notch1 protein was decreased and that of E-cadherin protein was increased (P <0.05).Conclusion Knockdown of miR-449a inhibited the normal growth of breast cancer xenografts in nude mice by down-regulating the expressions of Notch 1 andβ-catenin and promoting the expression of E-cadherin.