PTGS2 and cancer: An inverse relationship between E-cadherin and Cox-2 and its molecular mechanism in cancer cells was first shown in non-small cell lung cancer (NSCLC), in which Cox-2 overexpression led to decreased E-cadherin expression through the upregulation of PGE2 and transcriptional repressors of E-cadherin, whereas the inhibition of Cox-2 showed an inverse regulation of those molecules [37].