Tissue inhibitor of metalloproteinases-1 stimulates gene expression in MDA-MB-435 human breast cancer cells by means of its ability to inhibit metalloproteinases.
Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a widely expressed, secreted protein that functions primarily to inhibit members of a large family of metalloproteinases (MPs). Because of the ability of TIMP-1 to inhibit MPs, it functions in many of the same pathophysiological processes as these enzymes, e.g. wound healing, ovulation, angiogenesis, and cancer cell metastasis. TIMP-1 can also stimulate proliferation ([3H]thymidine incorporation) and cellular anabolic processes (Alamar Blue reduction). This stimulation has been shown to be dependent on the MP-inhibitory ability of TIMP-1 in the human breast cancer cell line MDA-MB-435 (Porter et al., Br J Cancer 90: 463, 2004). To shed light on the mechanism by which TIMP-1 stimulates cellular anabolic processes, an oligonucleotide microarray analysis was performed over a time course of TIMP-1 treatment of MDA-MB-435 cells. Fifteen genes whose mRNAs were differentially regulated were identified. Six (Importin-7, MGC10471, FOXC1, subunit p20 of Arp2/3 complex, mitochondrial ribosomal protein L32, and the serine/threonine kinase-4 (MST1)) of these genes were confirmed by quantitative real time PCR. These same mRNAs were shown to be regulated by the synthetic hydroxamate MP-inhibitor GM6001 but not by its inactive derivative GM6001*, suggesting that the differential regulation occurs through the MP-inhibitory ability of TIMP-1. These results suggest a complex action of TIMP-1 on cancer cells mediated by constitutively active cell surface metalloproteinases that release factors regulating cell signaling pathways; they may account for the paradoxical observation that elevated levels of TIMP-1 in tumors can correlate with an adverse prognosis.
Porter
Joseph F
JF
The Graduate Program in Microbiology and Molecular Genetics, Nelson Laboratories, Rutgers University, Piscataway, NJ 08854, USA.
Sharma
Shashi
S
Wilson
Donna L
DL
Kappil
Maya A
MA
Hart
Ronald P
RP
Denhardt
David T
DT
D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor / Q000187:drug effects; D017931:DNA Primers; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D045726:Metalloproteases / Q000037:antagonists & inhibitors* / Q000235:genetics; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000008:administration & dosage / Q000494:pharmacology*
D000970:Antineoplastic Agents; D017931:DNA Primers; D012333:RNA, Messenger; D019715:Tissue Inhibitor of Metalloproteinase-1; D045726:Metalloproteases