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.
Department of Urology, Osaka City University Medical School, Osaka, Japan.
R
R
Yoshimura
H
H
Sano
C
C
Masuda
M
M
Kawamura
Y
Y
Tsubouchi
J
J
Chargui
N
N
Yoshimura
T
T
Hla
S
S
Wada
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