RESUMEN
<p><b>OBJECTIVE</b>To investigate the expression of cyclooxygenase-2 (COX-2) in different prostate cancer (PCa) cell lines and its role in the acquisition of invasive and metastatic potentials of PCa.</p><p><b>METHODS</b>We detected the expressions of COX-2 in prostate cancer cell lines LNCaP, C4-2, IF11, IA8 and PC-3 with different metastatic potentials by Western blotting and RT-PCR, and analyzed their roles in the invasion and metastasis of different PCa cell lines.</p><p><b>RESULTS</b>Western blotting and RT-PCR showed that the expression of the COX-2 protein was high in PC-3, but absent in IF11, IA8, LNCaP and C4-2 (P < 0.05), and it was consistent with the expression of COX-2 mRNA.</p><p><b>CONCLUSION</b>COX-2 expresses differently in PCa cell lines with different metastatic potentials. The overexpression of COX-2 may be associated with the high invasion and metastasis of PC-3, but not with the metastasis of other cell lines.</p>