Adipocyte-derived monocyte chemotactic protein-1 (MCP-1) promotes prostate cancer progression through the induction of MMP-2 activity.
BACKGROUND
Obesity is known to be associated with prostate cancer development and progression, but the detailed mechanism is not clear. Monocyte chemotactic protein-1 (MCP-1) is secreted from cancer cells, stromal cells, and adipocytes, and it is involved in prostate cancer progression. Here we investigated the biological role of MCP-1 secreted from adipocytes for prostate cancer cells.


METHODS
Human pre-adipocytes (HPAds) were cultured and differentiated to mature adipocytes. Conditioned medium (CM) from HPAd cells was obtained using phenol red-free RPMI1640 medium. We performed a cytokine membrane array analysis to detect cytokines in the CM. To characterize the physiological function of MCP-1 in the CM, we performed an MTT-assay, a wound-healing and invasion assay with anti-MCP-1 antibody using three prostate cancer cell lines: DU145, LNCaP, and PC-3. Matrix metalloproteinase (MMP)-2 and MMP-9 activities were evaluated by gelatin zymography. A qPCR and Western blotting were used to examine the mRNA and protein expression levels of MMP-2.


RESULTS
The cytokine membrane array of the CM showed a strong signal of MCP-1compared to the control medium, and we thus focused our attention on MCP-1 in the CM. The CM up-regulated the cancer cell proliferation, and the neutralization by anti-MCP-1 antibody inhibited the proliferative effect of the prostate cancer cell lines. The CM greatly increased the invasive activity in the prostate cancer cell lines, and anti-MCP-1 antibody decreased the invasiveness. Gelatin zymography revealed that the CM markedly enhanced the enzymatic activity of MMP-2, and anti-MCP-1 antibody down-regulated its effect. MMP-2 mRNA expression was undetected and the MMP-2 protein level was unchanged between the control medium and CM in DU145 cells.


CONCLUSIONS
MCP-1 from adipocytes enhances the growth and invasion activity of prostate cancer cells. The inhibition of MCP-1 derived from adipocytes might be an effective treatment for prostate cancer.
Department of Urology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
Yusuke
Y
Ito
Department of Urology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.|Photocatalyst Group, Kanagawa Academy of Science and Technology, Kawasaki, Japan.
Hitoshi
H
Ishiguro
Department of Urology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
Naohito
N
Kobayashi
Department of Urology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
Hisashi
H
Hasumi
Laboratory for Medical Engineering, Division of Materials, Science and Chemical Engineering, Graduate School of Engineering, Yokohama National University, Yokohama, Japan.
Masatoshi
M
Watanabe
Department of Urology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
Masahiro
M
Yao
Department of Urology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
Hiroji
H
Uemura
D017667:Adipocytes / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000502:physiology*; D017077:Culture Media, Conditioned / Q000737:chemistry; D016207:Cytokines / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000032:analysis; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D011471:Prostatic Neoplasms / Q000201:enzymology / Q000473:pathology*; D012333:RNA, Messenger / Q000032:analysis; D054390:Receptors, CCR2 / Q000235:genetics
C111835:CCL2 protein, human; C515334:CCR2 protein, human; D018932:Chemokine CCL2; D017077:Culture Media, Conditioned; D016207:Cytokines; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D054390:Receptors, CCR2; D020778:Matrix Metalloproteinase 2
MCP-1; MMP-2; adipocyte; invasion; prostate cancer