COX-2 Inhibitor: NS-398 and Meloxican

Cyclooxygenase 2 (COX-2) 

is an Heme-Related Enzyme which catalyses the conversion of Arachidonic acid to a variety of Prostaglandins (including PG-E2).183

Over expression of COX-2 has been implicated in inflammation and reported in a number of human cancers including lung, breast, skin, prostate and colon cancers.183

Nimesulide is a selective

COX-2 inhibitor, and is known to inhibit proliferation

of tumor cells and induce tumor cell apoptosisin vitro,184,185

as well as prevent metastasis in vivo.186–188

Nonetheless, it has been suggested that COX-2
independent mechanisms are involved in nimesulidemediated
anti-tumor responses.189–191

Liang et al.191 reported the downregulation of B7-H1 expression in
IFN-c treated human breast cancer cells.

They showed that COX-2 inhibitors other than nimesulide
(NS-398 and meloxican) fail to inhibit B7-H1 expression.

Furthermore, addition of PG-E2 to IFN-c treated breast cancer cells did not inhibit nimesulidemediated B7-H1 downregulation, which indicated
that COX-2/PG-E2 independent mechanisms might
be involved191 (Table 1).

Inhibition of B7-H1 by Nimesulide can therefore be a potential therapeutic strategy to boost anti-tumor immune responses.