Effects of Jiazhu decoction in combination with cyclophosphamide on breast cancer in mice

To investigate the therapeutic effects of Jiazhu decoction (JZD) in combination with cyclophosphamide (CTX) on the growth of breast cancer in mice and to explore the possible molecular mechanisms of action.

BALB/c mice were randomly divided into four groups of 10 (untreated model group, JZD group, CTX group, and JZD + CTX group) and subcutaneously injected with 4T1 mouse breast cancer cells. Tumors were allowed to establish for ~7 d before initiation of treatment with CTX (100 mg/kg every week by intraperitoneal injection) and/or JZD (0.015 mL of 1.65 g/mL crude drug, administered daily by gavage). The model group received equivalent volumes of vehicle on the same schedules. Tumor volumes were measured every 3 d. Mice were sacrificed after 3 weeks of treatment, and tumors were excised and subjected to RT-qPCR and western blot analysis to evaluate expression of the Wnt/β-catenin signaling pathway components β-catenin, c-Myc, and cyclin D1 at the mRNA and protein levels.

The mean tumor volume was smaller and the growth rate was slower in the CTX and JZD + CTX groups compared with the model group (P < 0.05), and in the JZD + CTX group compared with the CTX and JZD groups (P < 0.05). Tumor growth was inhibited by 35.4% and 48.1% by CTX and JZD + CTX treatment, respectively (P < 0.001). The expression of β-catenin, c-Myc, and cyclin D1 mRNA and protein in tumors was significantly lower in mice treated with JZD or JZD + CTX compared with the untreated mice (P < 0.05), and was significantly lower in mice treated with JZD + CTX compared with either JZD or CTX alone (P < 0.05).

JZD inhibited the growth of mouse breast cancer cells in vivo, possibly by reducing the expression of β-catenin, c-Myc, and cyclin D1. Combination therapy with JZD plus CTX had a more potent inhibitory effect on breast cancer growth compared with either agent alone.