Differential regulation of TIMP-1 and TIMP-2 mRNA expression in normal and Ha-ras-transformed murine fibroblasts.
A cDNA containing the complete coding region of the murine tissue inhibitor of metalloproteinases-2 (TIMP-2) was isolated using reverse transcription-polymerase chain reaction amplification. The predicted murine TIMP-2 amino acid sequence shows 96% identity with human TIMP-2, but only 42% identity with murine TIMP-1. This high degree of evolutionary conservation between the human and mouse proteins suggests that TIMP-2 performs an essential biological function. The expression of the TIMP-1 and TIMP-2 mRNAs was examined in normal and ras-transformed murine fibroblasts. While TIMP-1 transcription was highly serum-inducible in normal murine C3H10T1/2 fibroblasts, TIMP-2 mRNA expression was largely constitutive. A series of ras-transformed derivatives of C3H10T1/2 fibroblasts showed great variability in TIMP-1 expression: some lines retained serum inducibility, others displayed constitutive expression at either high or low levels. In contrast, TIMP-2 expression was insensitive to transformation. Neither TIMP-1 nor TIMP-2 expression at the RNA level, or total TIMP activity in conditioned media could be correlated with the metastatic potential of the ras-transformed lines. Our data demonstrate that the mechanisms that regulate murine TIMP-1 and TIMP-2 expression are distinct arguing for different physiological roles for the two TIMPs.
Leco
K J
KJ
Department of Pharmacology and Therapeutics, University of Calgary, Alberta, Canada.
Hayden
L J
LJ
Sharma
R R
RR
Rocheleau
H
H
Greenberg
A H
AH
Edwards
D R
DR
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics*; D002461:Cell Line, Transformed; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D011905:Genes, ras / Q000235:genetics; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics*; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics*; D016133:Polymerase Chain Reaction; D019716:Tissue Inhibitor of Metalloproteinase-2; D019714:Tissue Inhibitor of Metalloproteinases
D002352:Carrier Proteins; D006023:Glycoproteins; D009363:Neoplasm Proteins; D019714:Tissue Inhibitor of Metalloproteinases; D019716:Tissue Inhibitor of Metalloproteinase-2; D008666:Metalloendopeptidases