The mRNA expression of cyclo-oxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in human breast cancer.
OBJECTIVE
There is a growing body of evidence that cyclo-oxygenase 2 (COX-2) plays an important role in carcinogenesis and angiogenesis of human tumours. The present study aims to compare COX-2 expression in human breast cancer and adjacent non-cancerous tissue (ANCT), and to identify any correlation between COX-2 and VEGF expression.


METHODS
Total cellular RNA was extracted from frozen breast tissue samples according to standard methodology. The mRNA copy numbers for COX-2 and vascular endothelial growth factor 189 (VEGF-189) were determined 40 infiltrating carcinomas and 40 matched ANCT specimens using quantitative RT-PCR and TaqMan methodology.


RESULTS
The COX-2 mRNA copy number per microg of RNA was two-fold higher in ANCT compared with the cancerous tissue (p = 0.01). Median mRNA copy number was 5.44 x 10(6) for ANCT and 2.30 x 10(6) for tumour, (ANCT range: 1 x 10(6) to 4.12x 10(7)) (tumour range: 1.29 x 10(5) to 1.07 x 10(7)). There was a significant correlation between COX-2 and VEGF-189 mRNA copy numbers in the cancer specimens (correlation coefficient = 0.5528, p = 0.0076).


CONCLUSIONS
COX-2 mRNA is overexpressed in both human breast cancer and ANCT. We found higher levels in the matched ANCT which suggests that paracrine effects may be important in the role of COX-2 in mammary carcinogenesis. Furthermore, our results indicate that in human breast cancers COX-2 overexpression is linked to VEGF-189 overexpression and therefore tumour angiogenesis.
St George's Hospital and Medical School, London, UK.
Katharine
K
Kirkpatrick
William
W
Ogunkolade
A
A
Elkak
Stephen
S
Bustin
Paul
P
Jenkins
Margaret
M
Ghilchik
Kefah
K
Mokbel
D001943:Breast Neoplasms / Q000378:metabolism*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism*; D051546:Cyclooxygenase 2; D016228:Endothelial Growth Factors / Q000378:metabolism*; D005260:Female; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism*; D008222:Lymphokines / Q000378:metabolism*; D008565:Membrane Proteins; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D036341:Intercellular Signaling Peptides and Proteins; D007527:Isoenzymes; D008222:Lymphokines; D008565:Membrane Proteins; D012333:RNA, Messenger; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases