Role of COX-2 in tumorospheres derived from a breast cancer cell line.
J Surg Res
; 168(1): e39-49, 2011 Jun 01.
Article
em En
| MEDLINE
| ID: mdl-20462604
ABSTRACT
BACKGROUND:
Cyclooxygenase-2 (COX-2) expression in primary breast cancer predicts tumor cell dissemination to bone marrow, which is a risk factor for recurrence and distant metastasis. "Stem-like" phenotype may be important in cancer metastasis.METHODS:
To investigate the role of COX-2 protein in breast cancer stem-like cells, we analyzed it by co-immunofluorescence in tumorospheres derived from the MCF7 estrogen receptor-positive breast cancer cell line. To evaluate COX-2 function we utilized a COX-2 inhibitor in a clonogenicity assay performed with tumorospheres-derived cells.RESULTS:
We detected rare cells in tumorospheres (one cell per tumorosphere) with very high COX-2 expression (COX-2(high)). COX-2 transfected MCF7 cells were able to generate long-term tumorospheres culture, even though transfection efficiency was only one in a million cells. We detected expression of OCT4 in some COX-2(high) cells, supporting the hypothesis that these cells could be cancer stem-like cells. It is important that COX-2(high) cells showed less expression of Ki-67 than did neighboring cells, indicating that COX-2(high) cells may be progenitors of tumorospheres. Celecoxib inhibited the growth of tumorosphere cultures and the ability of tumorosphere-derived cells to form colonies in vitro, indicating an active role of COX-2 in these processes. However, 2 µM celecoxib failed to eradicate tumorosphere-initiating cells. Finally, we detected rare COX-2(high) cells among SUM149 inflammatory breast cancer cells growing on plastic in serum-containing medium; the SUM149 cell line produces a very high level of COX-2 protein.CONCLUSION:
Our results support a role for COX-2 in stem-like breast cancer cells and suggest a mechanism behind a role for COX-2 in disseminated tumor cells, which are known to exhibit characteristic biomarkers and functional properties of stem-like cells.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Células-Tronco Neoplásicas
/
Neoplasias da Mama
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Ciclo-Oxigenase 2
Tipo de estudo:
Prognostic_studies
/
Risk_factors_studies
Limite:
Female
/
Humans
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article