OBJECTIVETo study the inhibitory effect and mechanism of Ganoderma lipsiense extract (GLE) on the growth of triple-negative breast cancer (TNBC) cell line MDA-MB-231-HM in a mouse model.

METHODSThe mouse model of TNBC was established by subcutaneous injection of 1.5 x 10(6) of MDA-MB-231-HM cells into BALB/c-nu mouse. Twenty successfully modeled mice were divided into the GLE group and the negative control group according to random digit table, 10 in each group. GLE (0.2 mL 100 mg/mL) was peritoneally injected to mice in the GLE group, while equal dose of normal saline was peritoneally injected to mice in the negative control group. The medication was administered once per 3 days and discontinued after 45 days. The CD34 expression was detected using immunohistochemical assay for counting microvessels. Meanwhile, expressions of thrombospondin 1 (TSP-1) and cyclin D1 were detected using immunohistochemical assay.

RESULTSThe average weight was obviously lower in the GLE group than in the negative control group [(0.33 ± 0.16) g vs (0.68 ± 0.37)g, P < 0.05]. The tumor inhibition rate was 51.4% in the GLE group. The volume of transplanted tumor was obviously lesser in the GLE group than in the negative control group (P < 0.05). Results of immunohistochemical staining showed, the microvessel density (MVD) under every field was (20.7 ± 2.1), TSP-1 positive cell count was (66.2 ± 9.2), cyclin D1 positive cell count was (33.8 ± 16.4) in the GLE group, and they were 34.0 ± 2.0, 24.0 ± 6.6, and 168.2 ± 32.6, respectively in the negative control group. There was statistical difference in all indices between the two groups (P < 0.05).

CONCLUSIONGLE could inhibit malignant proliferation of tumor cells by suppressing angiogenesis of blood vessels in tumor tissues and regulating cell cycles, thereby inhibiting TNBC.