Expression of cyclooxygenase-2 and 12-lipoxygenase in human breast cancer and their relationship with HER-2/neu and hormonal receptors: impact on prognosis and therapy.
BACKGROUND
A number of studies have shown over-expression of cox-2 in breast cancer. Also it has been recorded that human breast cancer expresses high level of cox-2 and 12-lipoxygenase which may be beneficial in future therapy plan for those patients.


OBJECTIVE
The present study aims to examine the level of transcripts of cox-2 and 12-lipoxygenase in Egyptian breast cancer patients and to compare between the expressions of both enzymes and TNM staging, hormone receptors status (including estrogen and progesterone) and HER2/neu expression.


METHODS
Total cellular RNA was extracted from 64 frozen tissue samples of breast carcinoma and their corresponding normal adjacent tissues. Cox-2 and 12-lipooxygenase expressions were detected using RT-PCR. Hormonal receptors as well as HER2/neu were detected immuno-histochemically for each patient.


RESULTS
About 47 and 62.5% of carcinoma samples showed over-expression of cox-2 and 12-lipooxygenase respectively as compared to their corresponding normal tissues. The results revealed that cox-2 significantly associated with TNM staging (P = 0.0047) and hormonal receptors status (P = 0.0201). The relationship between cox-2 and HER2/neu expression was close to a significant value (P = 0.0747). 12-lipooxygenase showed only significant association with TNM staging (P = 0.0076). Neither hormonal receptors nor HER2/neu showed significant association with this enzyme.


CONCLUSIONS
Elevated levels of cox-2 and 12-lipoxygenase expression were detected in human breast cancer. Also, the results revealed that cox-2 and 12-lipooxygenase mRNA expressions are associated with TNM staging in human breast cancer. Furthermore, there is an inverse association between cox-2 expression and hormonal receptor status. This observation may drive us to the possible role of those two enzymes in determining the plan of therapy of breast cancer patients.
Mohammad
A M
AM
Biochemistry and Molecular Biology Unit, Department of Cancer Biology, NCI, Cairo University, Egypt. mamnci@yahoo.com
Abdel
H A
HA
Abdel
W
W
Ahmed
A M
AM
Wael
T
T
Eiman
G
G
D000328:Adult; D000368:Aged; D001092:Arachidonate 12-Lipoxygenase / Q000235:genetics / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000032:analysis; D001940:Breast / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D018275:Carcinoma, Lobular / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D001092:Arachidonate 12-Lipoxygenase; D014408:Biomarkers, Tumor; D051546:Cyclooxygenase 2; D008565:Membrane Proteins; D012333:RNA, Messenger; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C496540:PTGS2 protein, human