Figure 4.

Autocrine TGF-β production and activation by αvβ6 in EMT cells. (A) ELISA was performed to measure secreted TGF-β levels in serum-free media (Media), media after washing (Wash), or overnight culture media from organoid or EMT cultures of LIM 1863 cells (Org, EMT). (B) Reporter and LIM 1863 cells were cultured 16–20 hours and lysed for measurement of luciferase activity. Results are for organoids (Org) and EMT cells (EMT). Addition of function-blocking anti-β6 monoclonal (3G9, 30 μg/ml) or control antibody (Con) is shown at the bottom. Relative luciferase activity (RLU) is the measured activity divided by the activity of the coculture of organoid (control) cells in the presence of function-blocking antibody. *P < 0.001.