A positive feedback loop between mesenchymal-like cancer cells and macrophages is essential to breast cancer metastasis.
The close vicinity of cancer cells undergoing epithelial-mesenchymal transition (EMT) and tumor-associated macrophages (TAMs) at the invasive front of tumors suggests that these two cell type may mutually interact. We show that mesenchymal-like breast cancer cells activate macrophages to a TAM-like phenotype by GM-CSF. Reciprocally, CCL18 from TAMs induces cancer cell EMT, forming a positive feedback loop, in coculture systems and humanized mice. Inhibition of GM-CSF or CCL18 breaks this loop and reduces cancer metastasis. High GM-CSF expression in breast cancer samples is associated with more CCL18(+) macrophages, cancer cell EMT, enhanced metastasis, and reduced patient survival. These findings suggest that a positive feedback loop between GM-CSF and CCL18 is important in breast cancer metastasis.
Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China; Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
Shicheng
S
Su
Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China; Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
Qiang
Q
Liu
Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China; Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China; Department of Medical Oncology, No. 2 Affiliated Hospital, Guangzhou Medical College, Guangzhou 510260, China.
Jingqi
J
Chen
Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China; Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
Jianing
J
Chen
Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China; Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
Fei
F
Chen
Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China; Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
Chonghua
C
He
Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China; Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
Di
D
Huang
Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China; Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
Wei
W
Wu
Department of Internal Medicine, The First Affiliated Hospital, Shantou University Medical College, Shantou 515041, China.
Ling
L
Lin
Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
Wei
W
Huang
Department of Breast Surgery, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China.
Jin
J
Zhang
Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
Xiuying
X
Cui
Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
Fang
F
Zheng
Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China; Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
Haiyan
H
Li
Department of Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
Herui
H
Yao
Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China; Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
Fengxi
F
Su
Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China; Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China. Electronic address: songew@mail.sysu.edu.cn.
Erwei
E
Song
D000818:Animals; D001943:Breast Neoplasms / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D045744:Cell Line, Tumor; D019742:Chemokines, CC / Q000037:antagonists & inhibitors / Q000097:blood / Q000378:metabolism*; D058750:Epithelial-Mesenchymal Transition; D025461:Feedback, Physiological; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000037:antagonists & inhibitors / Q000097:blood / Q000378:metabolism*; D006801:Humans; D061986:MCF-7 Cells; D008264:Macrophages / Q000276:immunology / Q000473:pathology*; D008648:Mesoderm / Q000166:cytology; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009362:Neoplasm Metastasis; D009368:Neoplasm Transplantation
C111792:CCL18 protein, human; D019742:Chemokines, CC; D016178:Granulocyte-Macrophage Colony-Stimulating Factor