Inhibition of cancer cell epithelial mesenchymal transition by normal fibroblasts via production of 5-methoxytryptophan.

We reported previously that human fibroblasts release 5-methoxytryptophan (5-MTP) which inhibits cancer cell COX-2 overexpression and suppresses cancer cell migration and metastasis. To determine whether fibroblasts block cancer cell epithelial mesenchymal transition (EMT) via 5-MTP, we evaluated the effect of Hs68 fibroblasts (HsFb) on A549 cancer cell EMT in a two-chamber system. Co-incubation of A549 with HsFb prevented TGF-β1-induced reduction of E-cadherin and increase in Snail and N-cadherin.