The membrane bile acid receptor TGR5 drives cell growth and migration via activation of the JAK2/STAT3 signaling pathway in non-small cell lung cancer

Mounting evidence suggests that an emerging G protein-coupled receptor, TGR5, plays a crucial role ranging from metabolic diseases to cancers. However, the biological functions of TGR5 in non-small cell lung cancer (NSCLC) remain elusive. We found that TGR5 was aberrantly expressed in NSCLC and positively correlated with an advanced clinical stage in NSCLC patients. We further discovered that TGR5 knockdown prevented JAK2 and STAT3 phosphorylation and repressed the expression of STAT3 target genes, thus inhibiting cell proliferation, migration and invasion in NSCLC. Moreover, the promotive effects of TGR5 were significantly reversed by a JAK2 inhibitor or STAT3 knockdown. Additionally, we demonstrated a positive correlation between TGR5 and p-STAT3 expression in NSCLC tissue samples. Patients with both high TGR5 and p-STAT3 expression had the worst prognosis. In addition, the serum levels of deoxycholic acid (DCA), ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) in NSCLC patients were much higher than those in the healthy controls and the patients with higher serum DCA levels had stronger TGR5 expression simultaneously. Moreover, DCA markedly promoted NSCLC cell migration and invasion through a TGR5-dependent way. Taken together, these results indicate that TGR5 drives cell growth and migration through JAK2/STAT3 signaling pathway in NSCLC.