一篇发表在PLoS ONE杂志上的文章研究人员通过分析老鼠的乳腺癌细胞的运动，发现有一类特殊的巨噬细胞(macrophages)能够使恶性肿瘤细胞在身体内发生转移。该研究发现的这类巨噬细胞或许能提供一种治疗癌症有用的靶标，通过药物治疗的方法或许能够阻断癌变的过程。
在这篇研究报告中，研究人员通过三种不同的方法表明，一旦这种特殊的巨噬细胞被杀死，那么就能够抑制转移性肿瘤的生长。他们还表明，即使动物的肺中已出现乳腺癌细胞，并在该位点开始生长，通过杀死这种特殊的巨噬细胞也可以显著地减缓转移性肿瘤细胞的生长。研究人员Pollard说，这些试验表明，即使对于那些已发生肿瘤转移的患者来说，这种抗巨噬细胞疗法也能发挥重要作用。这项发现是基于Pollard及其同事之前的研究：巨噬细胞能在肿瘤原发位点促进肿瘤发展和恶化。而本项研究则表明：巨噬细胞还能促进转移性肿瘤细胞的生长。（生物谷Bioon.com）
生物谷推荐原始出处：
PLoS ONE 4(8): e6562. doi:10.1371/journal.pone.0006562
A Distinct Macrophage Population Mediates Metastatic Breast Cancer Cell Extravasation, Establishment and Growth
Binzhi Qian1, Yan Deng1¤, Jae Hong Im2, Ruth J. Muschel2, Yiyu Zou3, Jiufeng Li1, Richard A. Lang4, Jeffrey W. Pollard1*
1 Department of Developmental and Molecular Biology and the Department of Obstetrics/Gynecology and Woman's Health, Center for the Study of Reproductive Biology and Woman's Health, Albert Einstein College of Medicine, Bronx, New York, United States of America, 2 Radiation Oncology & Biology, University of Oxford Churchill Hospital, Headington, United Kingdom, 3 Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, United States of America, 4 Division of Developmental Biology, Department of Ophthalmology, The Children's Hospital Research Foundation, Cincinnati, Ohio, United States of America
Background
The stromal microenvironment and particularly the macrophage component of primary tumors influence their malignant potential. However, at the metastatic site the role of these cells and their mechanism of actions for establishment and growth of metastases remain largely unknown.
Methodology/Principal Findings
Using animal models of breast cancer metastasis, we show that a population of host macrophages displaying a distinct phenotype is recruited to extravasating pulmonary metastatic cells regardless of species of origin. Ablation of this macrophage population through three independent means (genetic and chemical) showed that these macrophages are required for efficient metastatic seeding and growth. Importantly, even after metastatic growth is established, ablation of this macrophage population inhibited subsequent growth. Furthermore, imaging of intact lungs revealed that macrophages are required for efficient tumor cell extravasation.
Conclusion/Significance
These data indicate a direct enhancement of metastatic growth by macrophages through their effects on tumor cell extravasation, survival and subsequent growth and identifies these cells as a new therapeutic target for treatment of metastatic disease.
