Author Affiliations
Abstract
1 Department of Chemistry, Fudan University, Shanghai, P. R. China
2 Institutes of Biomedical Sciences, Fudan University, Shanghai, P. R. China
3 Department of Urology, Xinhua Hospital Shanghai Jiao Tong University 1665, Kongjiang Road, Shanghai 200092, P. R. China
4 Med-X Research Institute, Shanghai Jiao Tong University 1954, Huashan Road, Shanghai 200240, P. R. China
5 School of Biomedical Engineering Shanghai Jiao Tong University, Shanghai, P. R. China
Metastasis is a very complicated multi-step process and accounts for the low survival rate of the cancerous patients. To metastasize, the malignant cells must detach from the primary tumor and migrate to secondary sites in the body through either blood or lymph circulation. Macrophages appear to be directly involved in tumor progression and metastasis. However, the role of macrophages in affecting cancer metastasis has not been fully elucidated. Here, we have utilized an emerging technique, namely in vivo flow cytometry (IVFC) to study the depletion kinetics of circulating prostate cancer cells in mice and determine how depletion of macrophages by the liposome-encapsulated clodronate affects the depletion kinetics. Our results show different depletion kinetics of PC-3 cells between the macrophage-deficient group and the control group. The number of circulating tumor cells (CTCs) in the macrophage-deficient group decreases in a slower manner compared to the control mice group. The differences in depletion kinetics indicate that the absence of macrophages facilitates the stay of prostate cancer cells in circulation. In addition, our imaging data suggest that macrophages might be able to arrest, phagocytose and digest PC-3 cells. Therefore, phagocytosis may mainly contribute to the depletion kinetic differences. The developed methods elaborated here would be useful to study the relationship between macrophages and tumor metastasis in small animal cancer models.
Prostate cancer macrophages liposome-encapsulated clodronate in vivo flow cytometer circulating tumor cells Journal of Innovative Optical Health Sciences
2012, 5(4): 1250027