PTGS2 and pancreatic neoplasm: In the pancreatic cancer cell line, BxPC-3, inflammatory stimuli, such as lipopolysaccharides (LPS) or tumor necrosis factor alpha (TNF-α) significantly increase the expression of COX-2, PGE2, and MMP-9, and siRNA knockdown of COX-2 or treatment with the COX-2 selective inhibitor NS398 significantly reduces the increase in MMP-9 expression (28).