Figure 5. Effect of anit-DLK1 antibody on the bioactivity of PitNET cell lines. (A) Western blot assay measured the levels of DLK1 and PIT1 in GH3 cell line, MMQ cell line and ATT20 cell line. (B) Anti-DLK1 antibody inhibited the cell viability of GH3 cells in the dose- and time-dependent manner, not MMQ cells or ATT20 cells. (C) Anti-DLK1 antibody inhibited the secretion of GH/IGF-1 in GH3 cells, not PRL in MMQ cells and ACTH in ATT20 cells. (D) Clone forming experiment showed the anti-DLK1 antibody promoted the cell proliferation in GH3 cell line. (E) Confocal experiment showed DLK1 regulated the level of PIT1 in GH3 cell line. (F) Western blot experiment showed Anti-DLK1 antibody activated the mTOR pathway in GH3 cell line. *compare to control group P<0.05 **P<0.01 ***P<0.001.