Silencing cAMP-response element-binding protein (CREB) identifies CYR61 as a tumor suppressor gene in melanoma.
J Biol Chem
; 284(38): 26194-206, 2009 Sep 18.
Article
em En
| MEDLINE
| ID: mdl-19632997
ABSTRACT
Metastatic progression of melanoma is associated with overexpression and activity of cAMP-response element-binding protein (CREB). However, the mechanism by which CREB contributes to tumor progression and metastasis remains unclear. Here, we demonstrate that stably silencing CREB expression in two human metastatic melanoma cell lines, A375SM and C8161-c9, suppresses tumor growth and experimental metastasis. Analysis of cDNA microarrays revealed that CREB silencing leads to increased expression of cysteine-rich protein 61 (CCN1/CYR61) known to mediate adhesion, chemostasis, survival, and angiogenesis. Promoter analysis and chromatin immunoprecipitation assays demonstrated that CREB acts as a negative regulator of CCN1/CYR61 transcription by directly binding to its promoter. Re-expression of CREB in CREB-silenced cells rescued the low CCN1/CYR61 expression phenotype. CCN1/CYR61 overexpression resulted in reduced tumor growth and metastasis and inhibited the activity of matrix metalloproteinase-2. Furthermore, its overexpression decreased melanoma cell motility and invasion through Matrigel, which was abrogated by silencing CCN1/CYR61 in low metastatic melanoma cells. Moreover, a significant decrease in angiogenesis as well as an increase in apoptosis was seen in tumors overexpressing CCN1/CYR61. Our results demonstrate that CREB promotes melanoma growth and metastasis by down-regulating CCN1/CYR61 expression, which acts as a suppressor of melanoma cell motility, invasion and angiogenesis.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Regulação Neoplásica da Expressão Gênica
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Genes Supressores de Tumor
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Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico
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Inativação Gênica
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Proteína Rica em Cisteína 61
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Melanoma
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article