Expression of cyclooxygenase-2 in prostate carcinoma.
BACKGROUND
Nonsteroidal antiinflammatory drugs inhibiting cyclooxygenase (COX) enzyme activity in both its constitutive (COX-1) and inducible (COX-2) isoforms were shown also to inhibit the development of colon carcinoma in animal models. COX-2 is an inducer of angiogenesis of new blood vessels. The expression of COX-1 and COX-2 in prostate tissues from patients with prostate carcinoma was investigated using reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry.


METHODS
Tumor specimens were obtained from 28 prostate carcinoma (PC) patients, 8 benign prostatic hyperplasia (BPH) patients, 1 prostatic intraepithelial neoplasia (PIN) patient, and 8 specimens of normal prostate tissue (NP). Affinity-purified COX-1 and COX-2 antibodies were used in immunochemistry.


RESULTS
Very weak expression of COX-1 and marked expression of immunoreactive COX-2 in tumor cells was obtained. In contrast, expression of both isoforms was very weak in all cases of BPH and in the NP tissues. Immunoreactive COX-1 also was very weak in all cases of benign tissues. The extent and intensity of immunoreactive COX-2 polypeptides in tumor cells was statistically much greater than those of cells from BPH. Immunostaining with normal rabbit immunoglobulin G was completely negative. By RT-PCR analysis, enhanced expression of COX-2, but not COX-1, was observed in PC tissue. BPH displayed faint expression of COX-2.


CONCLUSIONS
The results of the current study demonstrated that human prostate carcinoma cells generated COX-2, and that COX-2 might play an important role in the proliferation of prostate carcinoma cells. These findings suggest that inhibition of COX-2 development may lead not only to inhibition of the proliferation and metastasis of prostate carcinoma but also to the inhibition of prostate carcinogenesis.
Yoshimura
R
R
Department of Urology, Osaka City University Medical School, Osaka, Japan.
Sano
H
H
Masuda
C
C
Kawamura
M
M
Tsubouchi
Y
Y
Chargui
J
J
Yoshimura
N
N
Hla
T
T
Wada
S
S
D000368:Aged; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism*; D011470:Prostatic Hyperplasia / Q000378:metabolism / Q000473:pathology; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction
D007527:Isoenzymes; D008565:Membrane Proteins; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases