title: Decreased expression of ADAMTS-1 in human breast tumors stimulates migration and invasion.
abstract: BACKGROUND
  ADAMTS-1 (a disintegrin and metalloprotease with thrombospondin motifs) is a member of the ADAMTS family of metalloproteases. Here, we investigated mRNA and protein levels of ADAMTS-1 in normal and neoplastic tissues using qPCR, immunohistochemistry and immunoblot analyses, and we addressed the role of ADAMTS-1 in regulating migration, invasion and invadopodia formation in breast tumor cell lines.
  
  
  RESULTS
  In a series of primary breast tumors, we observed variable levels of ADAMTS-1 mRNA expression but lower levels of ADAMTS-1 protein expression in human breast cancers as compared to normal tissue, with a striking decrease observed in high-malignancy cases (triple-negative for estrogen, progesterone and Her-2). This result prompted us to analyze the effect of ADAMTS-1 knockdown in breast cancer cells in vitro. MDA-MB-231 cells with depleted ADAMTS-1 expression demonstrated increased migration, invasion and invadopodia formation. The regulatory mechanisms underlying the effects of ADAMTS-1 may be related to VEGF, a growth factor involved in migration and invasion. MDA-MB-231 cells with depleted ADAMTS-1 showed increased VEGF concentrations in conditioned medium capable of inducing human endothelial cells (HUVEC) tubulogenesis. Furthermore, expression of the VEGF receptor (VEGFR2) was increased in MDA-MB-231 cells as compared to MCF7 cells. To further determine the relationship between ADAMTS-1 and VEGF regulating breast cancer cells, MDA-MB-231 cells with reduced expression of ADAMTS-1 were pretreated with a function-blocking antibody against VEGF and then tested in migration and invasion assays; both were partially rescued to control levels.
  
  
  CONCLUSIONS
  ADAMTS-1 expression was decreased in human breast tumors, and ADAMTS-1 knockdown stimulated migration, invasion and invadopodia formation in breast cancer cells in vitro. Therefore, this series of experiments suggests that VEGF is involved in the effects mediated by ADAMTS-1 in breast cancer cells.
authors.affiliation: Departamento de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av, Prof, Lineu Prestes 1524, Ed Biomédicas 1 sala 428, São Paulo, SP, 05508-000, Brazil. vfreitas@usp.br
authors.forename: Vanessa M
authors.initials: VM
authors.lastname: Freitas
authors.forename: Jônatas Bussador
authors.initials: JB
authors.lastname: do Amaral
authors.forename: Thaiomara A
authors.initials: TA
authors.lastname: Silva
authors.forename: Emerson S
authors.initials: ES
authors.lastname: Santos
authors.forename: Flávia R
authors.initials: FR
authors.lastname: Mangone
authors.forename: João de Jesus
authors.initials: Jde J
authors.lastname: Pinheiro
authors.forename: Ruy G
authors.initials: RG
authors.lastname: Jaeger
authors.forename: Maria A
authors.initials: MA
authors.lastname: Nagai
authors.forename: Gláucia Maria
authors.initials: GM
authors.lastname: Machado-Santelli
mesh_terms: D051722:ADAM Proteins / Q000235:genetics / Q000378:metabolism*; D000071097:ADAMTS1 Protein; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000201:enzymology* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000201:enzymology* / Q000556:secondary; D002465:Cell Movement; D022081:Cell Surface Extensions / Q000201:enzymology; D005260:Female; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D006801:Humans; D008207:Lymphatic Metastasis; D061986:MCF-7 Cells; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D034741:RNA, Small Interfering / Q000235:genetics; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D059008:Time-Lapse Imaging; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism; D055815:Young Adult
chemical_list: D051722:ADAM Proteins; D000071097:ADAMTS1 Protein; D034741:RNA, Small Interfering; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D042461:Vascular Endothelial Growth Factor A; D040301:Vascular Endothelial Growth Factor Receptor-2; C467484:VEGFA protein, human; C508053:ERBB2 protein, human; C103859:ADAMTS1 protein, human