Celecoxib, an anti-inflammation pill for arthritis, is being studied for its potential in preventing and treating certain cancers. In a large percentage of tumors, the COX-2 enzyme is elevated, say Ernest T. Hawk, M.D., M.P.H., of the National Cancer Institute, and his coworkers in an accompanying editorial. They point out that past studies have shown that decreasing levels of COX-2 can suppress the growth of tumors. However, it has been unclear whether celecoxibs anticancer effects depend on COX-2 inhibition alone.
To find out, Chen and his coworkers created prostate cancer cells lacking the COX-2 enzyme. In contrast to the effects of COX-2 inhibitors such as celecoxib, which induce cell death, cells that lacked COX-2 remained alive. Exposure of these cells lacking COX-2 to various COX-2 inhibitors did lead to cell death. Whats more, derivatives of celecoxib that did not block COX-2 activity also caused cell death.
The authors note that these events were associated not with levels of COX-2 but with decreased phosphorylation of Akt and ERK2 proteins. This mode of action differs from that of conventional anticancer drugs, they point out.
In the accompanying editorial, Hawk and his colleagues note that celecoxib is being tested for the treatment and prevention of colon cancer and that newer generations of COX-2 inhibitors could prove to be safer and more effective.
However, they point out that the current findings are based on concentrations of c
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Contact: Linda Wang
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Journal of the National Cancer Institute
16-Apr-2002