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(Referência obtida automaticamente do SciELO, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Alternagin-C binding to α2β1 integrin controls matrix metalloprotease-9 and matrix metalloprotease-2 in breast tumor cells and endothelial cells

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Autor(es):
Milene Nóbrega de Oliveira Moritz ; Lívia Mara Santos Eustáquio ; Kelli Cristina Micocci ; Ana Carolina Caetano Nunes ; Patty Karina dos Santos ; Tamires de Castro Vieira ; Heloísa Sobreiro Selistre-de-Araujo
Número total de Autores: 7
Tipo de documento: Artigo Científico
Fonte: Journal of Venomous Animals and Toxins including Tropical Diseases; v. 24, p. -, 2018.
Resumo

Abstract Background Matrix metalloproteinases (MMPs) are key players in tumor progression, helping tumor cells to modify their microenvironment, which allows cell migration to secondary sites. The role of integrins, adhesion receptors that connect cells to the extracellular matrix, in MMP expression and activity has been previously suggested. However, the mechanisms by which integrins control MMP expression are not completely understood. Particularly, the role of α2β1 integrin, one of the major collagen I receptors, in MMP activity and expression has not been studied. Alternagin-C (ALT-C), a glutamate-cysteine-aspartate-disintegrin from Bothrops alternatus venom, has high affinity for an α2β1 integrin. Herein, we used ALT-C as a α2β1 integrin ligand to study the effect of ALT-C on MMP-9 and MMP-2 expression as well as on tumor cells, fibroblats and endothelial cell migration. Methods ALT-C was purified by two steps of gel filtration followed by anion exchange chromatography. The α2β1, integrin binding properties of ALT-C, its dissociation constant (Kd) relative to this integrin and to collagen I (Col I) were determined by surface plasmon resonance. The effects of ALT-C (10, 40, 100 and 1000 nM) in migration assays were studied using three human cell lines: human fibroblasts, breast tumor cell line MDA-MB-231, and microvascular endothelial cells HMEC-1, considering cells found in the tumor microenvironment. ALT-C effects on MMP-9 and MMP-2 expression and activity were analyzed by quantitative PCR and gelatin zymography, respectively. Focal adhesion kinase activation was determined by western blotting. Results Our data demonstrate that ALT-C, after binding to α2β1 integrin, acts by two distinct mechanisms against tumor progression, depending on the cell type: in tumor cells, ALT-C decreases MMP-9 and MMP-2 contents and activity, but increases focal adhesion kinase phosphorylation and transmigration; and in endothelial cells, ALT-C inhibits MMP-2, which is necessary for tumor angiogenesis. ALT-C also upregulates c-Myc mRNA level, which is related to tumor suppression. Conclusion These results demonstrate that α2β1 integrin controls MMP expression and reveal this integrin as a target for the development of antiangiogenic and antimetastatic therapies. (AU)

Processo FAPESP: 14/17651-7 - A integrina alfa2beta1 na progressão tumoral mamária: papel no microambiente tumoral e na metástase
Beneficiário:Milene Nóbrega de Oliveira Moritz
Linha de fomento: Bolsas no Brasil - Doutorado
Processo FAPESP: 13/00798-2 - A matriz extracelular no envelhecimento, no exercício e no microambiente tumoral
Beneficiário:Heloisa Sobreiro Selistre de Araújo
Linha de fomento: Auxílio à Pesquisa - Temático