Thrombospondin 2 inhibits metastasis of human malignant melanoma through microenvironment-modification in NOD/SCID/gammaCnull (NOG) mice.
Thrombospondin (TSP) 2 interacts with matrix metalloproteinases (MMPs) and matrix serine proteases such as plasminogen activator (PA). Malignant melanoma is an aggressive human neoplasm showing aggressive metastatic features. We examined the effects of TSP2 gene introduction in the human malignant melanoma cell line A375. We established three clones transfected with human TSP2 (A375/TSP2). The in vitro invasiveness was remarkably suppressed (42-61%) in the TSP2-transfectants, while growth properties were preserved. The A375/TSP2 showed significantly decreased liver metastatic potential (liver weight: 3.88+/-0.30 g in A375/TSP2, 7.07+/-0.67 g in vector-transfectant (A375/V), p<0.01, Mann-Whitney U test) in super immuno-deficient mice (NOD/SCID/gammacnull, NOG). The PA inhibitor-1 (PAI-1) and PAI-2 mRNAs were significantly overexpressed in A375/TSP2. The increased activities of PAI-1 and PAI-2 were confirmed by reverse zymography. The vascularity of metastatic lesions was significantly decreased in A375/TSP2 (vascular density: 0.62+/-0.15% in A375/TSP2, 4.96+/-0.61% in A375/V, p<0.01, Welch test). These results suggest that TSP2 suppresses hematogenous metastasis through microenvironment-modification including PAI up-regulation and anti-vascularization in human malignant melanoma.
Chijiwa
Tsuyoshi
T
Department of Pathology, Tokai University School of Medicine, Shimokasuya, Isehara, Kanagawa 259-1193, Japan.
Abe
Yoshiyuki
Y
Ikoma
Norihiro
N
Yamazaki
Hitoshi
H
Tsukamoto
Hideo
H
Suemizu
Hiroshi
H
Kawai
Kenji
K
Wakui
Masatoshi
M
Nishime
Chiyoko
C
Matsumoto
Hozumi
H
Matsuyama
Masahiro
M
Mukai
Masaya
M
Ueyama
Yoshito
Y
Nakamura
Masato
M
D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002465:Cell Movement; D004797:Enzyme-Linked Immunosorbent Assay; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D008114:Liver Neoplasms, Experimental / Q000235:genetics / Q000517:prevention & control*; D008297:Male; D008546:Melanoma, Experimental / Q000235:genetics / Q000517:prevention & control*; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009361:Neoplasm Invasiveness; D009389:Neovascularization, Pathologic; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics; D017396:Plasminogen Activator Inhibitor 2 / Q000235:genetics; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019699:Thrombospondins / Q000235:genetics*; D014162:Transfection; D000099262:Thrombospondin 2
D017395:Plasminogen Activator Inhibitor 1; D017396:Plasminogen Activator Inhibitor 2; D012333:RNA, Messenger; D019699:Thrombospondins; D000099262:Thrombospondin 2