Total alkaloids of Coptidis Rhizoma combined with exercise inhibits tumor growth of orthotopically transplanted 4T1 breast cancer mice by blocking cell cycle G_1/S transformation

Abstract

Breast cancer is one of the leading causes for cancer-related death among women worldwide. Coptidis Rhizoma has antibacterial,anti-inflammatory,anti-tumor and other pharmacological activities,but whether exercise could synergistically promote the role of RC in the treatment of breast cancer has not been reported. In this experiment,the effects and mechanism of total alkaloids of Coptidis Rhizoma combined with exercise on the tumor growth of orthotopically transplanted 4 T1 breast cancer were systemically studied in mice. Balb/C mice transplanted with 4 T1 cells in situ were used as models. The total alkaloids of RC(145 mg·kg-1·d-1) alone or in combination with exercise(10 m·min-1,30 min/time,5 times/week) were given for 28 days,and then the changes in body weight and tumor volume,tumor weight,interleukin-1β(IL-1β),serum estradiol(E2) content,and expression levels of estrogen receptor α(ERα),cell cycle related proteins CDK4,CDK6,cyclin D1,CDK2,and cyclin E in tumor tissues. The results showed that total alkaloids of Coptidis Rhizoma could significantly inhibit the growth of 4 T1 breast cancer in mice(P< 0. 01),and exercise significantly promoted the anti-tumor activity of total alkaloids of Coptidis Rhizoma(P<0. 01),and reduced E2 and IL-1β levels in mice. Western blot and flow cytometry showed that the total alkaloids of Coptidis Rhizoma combined with exercise could down-regulate the protein expression levels of ERα,CDK4,CDK6,cyclin D1,CDK2 and cyclin E in cancer cells,block the transformation of G1/S in 4 T1 cell cycle,and inhibit DNA synthesis in breast cancer cells. The total alkaloids of Coptidis Rhizoma combined with exercise showed synergistic effect in inhibition of tumor growth in mice with orthotopically transplanted 4 T1 breast cancer.