Reconstitution of TIMP-2 expression in SH-SY5Y neuroblastoma cells by 5-azacytidine is mediated transcriptionally by NF-Y through an inverted CCAAT site
Articolo
Data di Pubblicazione:
2003
Citazione:
Reconstitution of TIMP-2 expression in SH-SY5Y neuroblastoma cells by 5-azacytidine is mediated transcriptionally by NF-Y through an inverted CCAAT site / L. Cappabianca, A.R. Farina, A. Tacconelli, R. Mantovani, A. Gulino, A.R. MacKay. - In: EXPERIMENTAL CELL RESEARCH. - ISSN 0014-4827. - 286:2(2003), pp. 209-218.
Abstract:
Advanced stage neuroblastomas (NB) exhibit a tissue inhibitor of metalloproteinase (TIMP)-2/matrix metalloproteinase (MMP) imbalance, considered a prerequisite for MMP involvement in tumor progression in vivo. Human SH-SY5Y NB cells exhibit a similar TIMP-2/MMP imbalance that promotes in vitro invasive behavior that is inhibited by exogenous TIMP-2. The DNA methyltransferase inhibitor 5-azacytidine (5-AzaC) redresses this TIMP-2/MMP imbalance, reconstituting TIMP-2 expression, without effecting that of MMP-2, by stimulating TIMP-2 transcription and inhibiting in vitro invasivity of SH-SY5Y cells. 5-AzaC stimulated transcription from a nonmethylated TIMP-2 promoter reporter gene construct consistent with regulation of a TIMP-2 transactivator. Promoter deletion and point-mutation analysis localized this effect to an inverted CCAAT element at position −73. This element bound specific complexes containing NF-YA and NF-YB proteins in SH-SY5Y nuclear extracts, the binding of which was augmented by 5-AzaC in association with enhanced levels of NF-YB protein and the function of which was confirmed by inhibition using dominant-negative NF-YA. The data highlight a novel indirect methylation-mediated mechanism for regulating the TIMP/MMP equilibrium in NB cells, involving repression of TIMP-2 relative to MMP-2 expression, dependent upon suboptimal NF-Y transcription factor function, which can be reversed by methyltransferase inhibition.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
5-Azacytidine; Invasion; Inverted CCAAT element; Methylation; MMP-2; Neuroblastoma; NF-Y; TIMP-2
Elenco autori:
L. Cappabianca, A.R. Farina, A. Tacconelli, R. Mantovani, A. Gulino, A.R. MacKay
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