Expression cloning of novel regulators of 92 kDa type IV collagenase expression

2005 ◽  
Vol 33 (5) ◽  
pp. 1135 ◽  
Author(s):  
D.D. Boyd ◽  
R.R. Nair
Keyword(s):  
Expression Cloning ◽  
Type Iv Collagenase ◽  
Type Iv

Expression cloning of novel regulators of 92 kDa type IV collagenase expression

2005 ◽  
Vol 33 (5) ◽  
pp. 1135-1136 ◽  
Author(s):  
R.R. Nair ◽  
D.D. Boyd
Keyword(s):  
Dna Sequencing ◽  
Cancer Progression ◽  
Luciferase Reporter ◽  
Expression Cloning ◽  
Cdna Expression Library ◽  
Cdna Clones ◽  
Type Iv Collagenase ◽  
Expression Library ◽  
Type Iv ◽  
Ht1080 Cells

Overexpression of the 92 kDa type IV collagenase (MMP-9) contributes to cancer progression. However, to date, there are few known regulators of expression of this metalloproteinase. We employed an expression library comprising 500000 cDNA clones to screen for novel regulators of MMP-9 expression. HT1080 cells were transiently co-transfected with an MMP-9 promoter-luciferase reporter and pools of the cDNA expression library. Positive-scoring pools were subdivided in secondary and tertiary screens, after which the regulatory cDNAs were identified by DNA sequencing. This brief review illustrates the utility of expression cloning in identifying specific regulators of MMP-9 expression.

Induction of tissue-type plasminogen activator and 72-kDa type-IV collagenase by ionizing radiation in rat astrocytes

1994 ◽  
Vol 56 (2) ◽  
pp. 214-218 ◽  
Author(s):  
Raymond Sawaya ◽  
Philip J. Tofion ◽  
Sanjeeva Mohanam ◽  
Francis Ali-Oosman ◽  
Lance A. Liotta ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Plasminogen Activator ◽  
Tissue Type ◽  
Type Iv Collagenase ◽  
Tissue Type Plasminogen Activator ◽  
Type Iv ◽  
Type Plasminogen Activator ◽  
Rat Astrocytes

Positive and negative transcriptional elements of the human type IV collagenase gene

1990 ◽  
Vol 10 (12) ◽  
pp. 6524-6532
Author(s):  
S M Frisch ◽  
J H Morisaki
Keyword(s):  
Core Promoter ◽  
Type Iv Collagenase ◽  
Mobility Shift ◽  
Specific Expression ◽  
Enhancer Element ◽  
Type Iv ◽  
Dnase I Footprinting ◽  
Gel Mobility Shift ◽  
Transcriptional Elements ◽  
Mcf 7

Proteolysis by type IV collagenase (T4) has been implicated in the process of tumor metastasis. The T4 gene is expressed in fibroblasts, but not in normal epithelial cells, and its expression is specifically repressed by the E1A oncogene of adenovirus. We present an investigation of the transcriptional elements responsible for basal, E1A-repressible, and tissue-specific expression. 5'-Deletion analysis, DNase I footprinting, and gel mobility shift assays revealed a strong, E1A-repressible enhancer element, r2, located about 1,650 bp upstream of the start site. This enhancer bound a protein with binding specificity very similar to that of the transcription factor AP-2. A potent silencer sequence was found 2 to 5 bp downstream of this enhancer. The silencer repressed transcription from either r2 or AP-1 enhancer elements and in the context of either type IV collagenase or thymidine kinase (tk) gene core promoters; enhancerless transcription from the latter core promoter was also repressed. Comprising the silencer were two contiguous, autonomously functioning silencer elements. Negative regulation of T4 transcription by at least two factors was demonstrated. mcf-7 proteins specifically binding both elements were detected by gel mobility shift assays; a protein of approximately 185 kDa that bound to one of these elements was detected by DNA-protein cross-linking. The silencer repressed transcription, in an r2 enhancer-tk promoter context, much more efficiently in T4-nonproducing cells (mcf-7 or HeLa) than in T4-producing cells (HT1080), suggesting that cell type-specific silencing may contribute to the regulation of this gene.

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