Sequence-specific silencing of MT1-MMP expression suppresses tumor cell migration and invasion: importance of MT1-MMP as a therapeutic target for invasive tumors.
Membrane-type 1 matrix metalloproteinase (MT1-MMP/MMP-14) has been believed a key enzyme in tumor invasion, because it is expressed in a variety of malignant human tumors, and overexpression of the enzyme enhances the ability of cellular invasiveness. However, it has not necessarily been clarified whether the endogenously expressed MT1-MMP in human tumors plays a critical role in their invasiveness. We used RNA silencing technology to downregulate the endogenous MT1-MMP expression in human tumor cells (fibrosarcoma HT1080 and gastric carcinoma MKN-28 cell lines), and evaluated the effect on the invasion of a reconstituted basement membrane (Matrigel). Transfection of a double-stranded RNA targeted to the MT1-MMP gene decreased the level of the enzyme to less than 10-20% without affecting production of other MMPs. According to the degree of silencing, activation of proMMP-2 was inhibited. CD44 shedding was also inhibited, but only in part. Decreased MT1-MMP levels were also reflected in reduced cell motility on hyaluronan (HA) and invasion in Matrigel. Thus, specific downregulation of MT1-MMP expression was sufficient to cause significant inhibition of the migration and invasion of tumor cells, even though other MMPs continued to be expressed.
Ueda
Junko
J
Division of Cancer Cell Research, Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, Japan.
Kajita
Masahiro
M
Suenaga
Naoko
N
Fujii
Katsuyuki
K
Seiki
Motoharu
M
D045744:Cell Line, Tumor; D002465:Cell Movement; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000378:metabolism; D018093:Gelatinases / Q000378:metabolism; D020868:Gene Silencing; D006801:Humans; D018960:Hyaluronan Receptors / Q000502:physiology; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D009361:Neoplasm Invasiveness; D009369:Neoplasms / Q000628:therapy*; D012330:RNA, Double-Stranded / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis; D013274:Stomach Neoplasms / Q000473:pathology
D004792:Enzyme Precursors; D018960:Hyaluronan Receptors; D012330:RNA, Double-Stranded; D012333:RNA, Messenger; D018093:Gelatinases; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; C069860:progelatinase