Expression of prostaglandin G/H synthase-1 and-2 protein in human colon cancer

SL Kargman, GP O'Neill, PJ Vickers, JF Evans… - Cancer research, 1995 - AACR
SL Kargman, GP O'Neill, PJ Vickers, JF Evans, JA Mancini, S Jothy
Cancer research, 1995AACR
Abstract Prostaglandin G/H synthase (PGHS), a key enzyme leading to the formation of
prostaglandins, is the target of nonsteroidal antiinflammatory drugs. Two forms of the
enzyme have been identified, PGHS-1 and PGHS-2. Epidemiological evidence has
suggested that aspirin and other nonsteroidal antiinflammatory drugs may reduce the risk of
colorectal cancer. We examined by immunoblot analyses the expression of human PGHS-1
and PGHS-2 protein in 25 matched colon cancer and nontumor tissues, 4 premalignant …
Abstract
Prostaglandin G/H synthase (PGHS), a key enzyme leading to the formation of prostaglandins, is the target of nonsteroidal antiinflammatory drugs. Two forms of the enzyme have been identified, PGHS-1 and PGHS-2. Epidemiological evidence has suggested that aspirin and other nonsteroidal antiinflammatory drugs may reduce the risk of colorectal cancer. We examined by immunoblot analyses the expression of human PGHS-1 and PGHS-2 protein in 25 matched colon cancer and nontumor tissues, 4 premalignant polyps, 5 control colon tissues from noncancer patients, and 3 matched normal and cancerous breast tissue samples. PGHS-1 was detected in all normal and tumor tissue. In contrast, PGHS-2 was not detected in 23 of 25 normal colon tissues but was detected in 19 of 25 colon tumors. PGHS-2 protein was not observed in four human premalignant polyp samples, control colon from noncancer patients, or matched normal or cancerous breast tissues. These results suggest that the beneficial effects of nonsteroidal antiinflammatory drugs in colon cancer may be mediated by inhibition of PGHS-2.
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