Effect of inhibition of COX2 expression and celecoxib treatment in a model of murine lung adenocarcinoma

4691 COX2 has been postulated as a key mediator in cancer development. It was shown to modulate tumor growth in patients as well as in murine models. It is supported partly by high COX2 expression in tumor tissues and abrogation of tumor progression by specific COX2 inhibitors like celecoxib (CXB). However, it has not yet been elucidated if COX2 expression is necessary for NSAIDs to inhibit tumor progression. We investigated the effects of CXB in a murine lung adenocarcinoma cell line (LP07) that expresses COX-2 protein and was stably transfected with an antisense vector for COX-2 mRNA (LP07AS). We have first assessed the effect of CXB on tumor growth in BALB/c mice inoculated sc with LP07 cells. CXB reduced tumor growth (P