[Effects of metformin on papillary thyroid carcinoma in nude rats model]

Objective:To establish an subcutaneous xenotransplanted tumor model of papillary thyroid carcinoma (PTC) and investigate the role of metformin in apoptosis of PTC.Method:Model rats were randomly divided into four groups: control group, Met group and Met+DM group. The tumor volumes were recorded each week. Flow cytometry was used to detect the apoptosis rate of tumor. Immunohistochemistry was used to detect CyclinD1 and the cellular proliferative activity index PCNA and Ki-67.Result:Compared to the control group,there were a significant decrease in tumor volume and antitumor effect in Met and Met+DM groups. The apoptosis rate increased in Met and Met+DM groups. While compared with the control group, the expressions of PCNA,CyclinD1 and Ki-67 significantly decreased in Met and Met+DM groups. There was no difference between Met and Met+DM group.Conclusion:The effect of Metformin on inhibiting tumor growth were related with the imbalance of cell proliferation and apoptosis.