Elevated cell migration, invasion and tumorigenicity in human KB carcinoma cells transfected with COX-2 cDNA.
In order to investigate the involvement of cyclooxygenase (COX)-2 in cell growth and invasion of oral cancer, a human epidermoid carcinoma cell line KB minimally expressing COX-2 protein was transfected with COX-2 cDNA and these activities were compared with mock-transfected KB in vitro and in vivo. KB/COX-2 clones showed a similar growth rate in vitro compared to KB/neo clones, but demonstrated significantly increased PGE2 production, cell migration and invasion. These KB/COX-2 clones markedly expressed MMP-9, pro-MMP-2 and activated-MMP-2 as compared to KB/neo clones in gelatin zymography. Western blot analysis showed that expression of MT1-MMP, Rho and Rac 1 in KB/COX-2 clones were stronger than that in KB/neo clones, but expression of TIMP-1 and TIMP-2 were weaker in KB/COX-2 clones than in KB/neo clones. When these cells were inoculated subcutaneously into nude mice, tumorigenicity and tumor growth were significantly elevated in KB/COX-2 tumors than in KB/neo tumors, and the gelatinase activity was much stronger in KB/COX-2 tumor tissues than in KB/neo tumor tissues in film in situ zymography. The orthotopic inoculation of cells to the oral floor showed that local invasion was pronounced in KB/COX-2 tumors. These results indicated that overexpression of COX-2 elevated tumorigenicity, tumor growth and invasion of human KB carcinoma cells via up-regulated MMP and Rho family small GTPases and down-regulated TIMP activities.
Takaoka
Kazuki
K
Department of Oral and Maxillofacial Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan.
Kishimoto
Hiromitsu
H
Segawa
Emi
E
Hashitani
Susumu
S
Zushi
Yusuke
Y
Noguchi
Kazuma
K
Sakurai
Kazunari
K
Urade
Masahiro
M
D000818:Animals; D002277:Carcinoma / Q000201:enzymology* / Q000235:genetics / Q000473:pathology*; D002465:Cell Movement / Q000235:genetics; D051545:Cyclooxygenase 1 / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D015536:Down-Regulation; D006801:Humans; D007624:KB Cells; D008565:Membrane Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D045726:Metalloproteases / Q000032:analysis / Q000378:metabolism; D051379:Mice; D009361:Neoplasm Invasiveness; D019714:Tissue Inhibitor of Metalloproteinases / Q000032:analysis / Q000378:metabolism; D015533:Transcriptional Activation; D014162:Transfection; D015854:Up-Regulation; D020741:rho GTP-Binding Proteins / Q000032:analysis / Q000378:metabolism
D018076:DNA, Complementary; D008565:Membrane Proteins; D019714:Tissue Inhibitor of Metalloproteinases; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D045726:Metalloproteases; D020741:rho GTP-Binding Proteins