Silibinin inhibits accumulation of myeloid‐derived suppressor cells and tumor growth of murine breast cancer

Cancer Medicine

Parvin Forghani¹  Mohammad R. Khorramizadeh² 

[1] Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran;School of Public Health, Department of Medical Biotechnology, School of Advanced Medical Technologies Tehran University of Medical Sciences, Tehran, Iran

关键词: 4T1;    breast cancer;    mice;    myeloid‐derived suppressor cells;    SCID;    silibinin;   

DOI  :  10.1002/cam4.186

来源: Wiley

【 摘 要 】

Abstract

Myeloid-derived suppressor cells (MDSC)s increase in blood and accumulate in the tumor microenvironment of tumor-bearing animals, contributing to immune suppression in cancer. Silibinin, a natural flavonoid from the seeds of milk thistle, has been developed as an anti-inflammatory agent and supportive care agent to reduce the toxicity of cancer chemotherapy. The goals of this study were to evaluate the effect of silibinin on MDSCs in tumor-bearing mice and antitumor activity of silibinin in a mouse model of breast cancer. 4T1 luciferase-transfected mammary carcinoma cells were injected into in the mammary fat pad female BALB/c mice, and female CB17-Prkdc Scid/J mice. Silibinin treatment started on day 4 or day 14 after tumor inoculation continued every other day. Tumor growth was monitored by bioluminescent imaging (BLI) measuring total photon flux. Flow cytometry measured total leukocytes, CD11b⁺ Gr-1⁺ MDSC, and T cells in the blood and tumors of tumor-bearing mice. The effects of silibinin on 4T1 cell viability in vitro were measured by BLI. Treatment with silibinin increased overall survival in mice harboring tumors derived from the 4T1-luciferase breast cancer cell line, and reduced tumor volumes and numbers of CD11b⁺Gr-1⁺ MDSCs in the blood and tumor, and increased the content of T cells in the tumor microenvironment. Silibinin failed to inhibit tumor growth in immunocompromised severe combined immunodeficiency mice, supporting the hypothesis that anticancer effect of silibinin is immune-mediated. The antitumor activity of silibinin requires an intact host immune system and is associated with decreased accumulation of blood and tumor-associated MDSCs.

【 授权许可】

CC BY   
© 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.