TY - JOUR
T1 - COX-2 overexpression increases motility and invasion of breast cancer cells.
AU - Singh, Balraj
AU - Berry, Jacob A.
AU - Shoher, Angela
AU - Ramakrishnan, Vijay
AU - Lucci, Anthony
N1 - Copyright:
This record is sourced from MEDLINE/PubMed, a database of the U.S. National Library of Medicine
PY - 2005/5
Y1 - 2005/5
N2 - Cyclooxygenase-2 (COX-2), an inducible enzyme involved in prostaglandin (including PGE(2)) biosynthesis, is overexpressed in several epithelial malignancies including breast cancer. We tested the hypothesis that COX-2 overexpression in breast cancer cells results in increased cell motility and invasion. COX-2 overproducing cells were generated by stable transfection of several human breast cancer cells with pSG5-COX2 vector. We confirmed the overexpression of COX-2 protein by western blotting, and by measuring PGE(2) in the medium with an immunoassay. We measured cell motility by counting the number of cells crossing an 8-micron pore size PET membrane, and cell invasion by counting the number of cells invading through a Matrigel-coated membrane that simulates basement membrane. COX-2 transfected MDA-231 cells produced 30-43-fold more PGE2 as compared to parental cells. COX-2 overexpression increased cell migration approximately 2.2-fold and cell invasion through Matrigel approximately 5.1-fold. Addition of 50 microM NS-398, a COX-2 inhibitor, inhibited Matrigel invasion of MDA-231 cells by 54% as compared to solvent confirming the role of COX-2 in cell invasion. It is known that an increase in cell migration and invasion can be brought about by cytoskeletal alterations and basement membrane degradation due to increased expression of pro-urokinase plasminogen activator (pro-uPA). To investigate the mechanism of our observed increase in cell invasion by COX-2, we found by western blotting that the level of pro-uPA was significantly higher (approximately 5-fold) in COX-2 transfected MDA-231 cells than untransfected MDA-231 cells. Similar to our observations in cell culture, we found evidence that increased COX-2 activity correlates with uPA in a mouse model of breast cancer metastasis to bone. In this study, we conclude that COX-2 overexpression in human breast cancer cells enhances cell motility and invasiveness thus suggesting a mechanism of COX-2 mediated metastasis.
AB - Cyclooxygenase-2 (COX-2), an inducible enzyme involved in prostaglandin (including PGE(2)) biosynthesis, is overexpressed in several epithelial malignancies including breast cancer. We tested the hypothesis that COX-2 overexpression in breast cancer cells results in increased cell motility and invasion. COX-2 overproducing cells were generated by stable transfection of several human breast cancer cells with pSG5-COX2 vector. We confirmed the overexpression of COX-2 protein by western blotting, and by measuring PGE(2) in the medium with an immunoassay. We measured cell motility by counting the number of cells crossing an 8-micron pore size PET membrane, and cell invasion by counting the number of cells invading through a Matrigel-coated membrane that simulates basement membrane. COX-2 transfected MDA-231 cells produced 30-43-fold more PGE2 as compared to parental cells. COX-2 overexpression increased cell migration approximately 2.2-fold and cell invasion through Matrigel approximately 5.1-fold. Addition of 50 microM NS-398, a COX-2 inhibitor, inhibited Matrigel invasion of MDA-231 cells by 54% as compared to solvent confirming the role of COX-2 in cell invasion. It is known that an increase in cell migration and invasion can be brought about by cytoskeletal alterations and basement membrane degradation due to increased expression of pro-urokinase plasminogen activator (pro-uPA). To investigate the mechanism of our observed increase in cell invasion by COX-2, we found by western blotting that the level of pro-uPA was significantly higher (approximately 5-fold) in COX-2 transfected MDA-231 cells than untransfected MDA-231 cells. Similar to our observations in cell culture, we found evidence that increased COX-2 activity correlates with uPA in a mouse model of breast cancer metastasis to bone. In this study, we conclude that COX-2 overexpression in human breast cancer cells enhances cell motility and invasiveness thus suggesting a mechanism of COX-2 mediated metastasis.
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U2 - 10.3892/ijo.26.5.1393
DO - 10.3892/ijo.26.5.1393
M3 - Article
C2 - 15809733
AN - SCOPUS:21444441914
SN - 1019-6439
VL - 26
SP - 1393
EP - 1399
JO - International journal of oncology
JF - International journal of oncology
IS - 5
ER -