Cyclooxygenase inhibitors not inhibit resting lung cancer A549 cell proliferation

Cyclooxygenase (COX) inhibitors were regarded as anticarcinogenic agents for lung cancer at least partly via PGE(2); but these were based on cytokin stimulation experiment on A549 cell. In order to clarify whether COX inhibitors directly inhibit A549 cell, three COX inhibitors, NS398 (selective COX-2 inhibitor), SC560 (selective COX-1 inhibitor), and acetyl salicylic acid (ASA, non-selective COX inhibitor), were studied. NS398, and ASA(,) can inhibit PGE(2) generation via COX-2 inhibition. The viability of A549 cell was assayed by MTT. However, without cytokin stimulation, all the three inhibitors (NS398 0.2-20 mu M: SC560 1.0-100nM; ASA 0.01-1.0 mM) were not able to inhibit A549 cell proliferation, in the other way round. NS398 promoted cell growth. And arachidonic acid (AA) and lipopolysaccharide (LPS) did not disturb the property of its growth. These data suggested that without cytokin stimulation. COX and PGE(2) may not be the kernel molecules involved in A549 cell proliferation. and COX inhibitors could not inhibit A549 cell growth directly. (c) 2006 Elsevier Ltd. All rights reserved.