Purpose: Cyclooxygenase-2 is considered to have an important role in the de
velopment of metastasis in cancer due to angiogenesis function. The express
ion of cyclooxygenase-2 was found to be up-regulated in colorectal carcinom
a and other cancers. We investigated cyclooxygenase-l and 2 expressions in
patients with bladder cancer, chronic cystitis and normal bladder.
Materials and Methods: A total of 118 specimens were obtained from patients
treated at Osaka City University Hospital for bladder cancer, including 10
with chronic cystitis and 8 with normal bladder tissue. Immunohistochemist
ry, with affinity purified antibodies against human cyclooxygenase-1 and 2
that did not have cross-reactivity with each other? and reverse transcripta
se polymerase chain reaction to study the messenger RNA expression were per
formed.
Results: Although no marked expression of cyclooxygenase-2 was observed in
the normal bladder, it was slightly seen in infiltrative inflammatory cells
of chronic cystitis, and a higher expression was found in cancer cells. Th
e extent and intensity of immunoreactive cyclooxygenase-2 polypeptides in c
ancer cells was statistically much greater than these in cells fi crm norma
l bladder tissue. Moreover, correlation between cyclooxygenase-2 expression
and tissue type. or progression of bladder cancer was observed. Cyclooxyge
nase-2 expression was higher in grade 3 bladder cancer than in grade 1, and
was higher in advanced than in early stage cancer.
Conclusions: These results demonstrate that generated cyclooxygenase-2 in t
he cells of patients with bladder cancer might be significant in the prolif
eration of bladder malignant cells and development of invasions.