The H19-overexpression cell medium can inhibit normal GH3 cell proliferation in vitro. (A) The H19-overexpression cell medium can inhibit normal GH3 cell proliferation in vitro. For 4 d, cell viability was periodically measured with an MTS assay (n = 3). **P < 0.001. (B) H19-overexpression cell medium reduced the colony formation rate of GH3 cells. GH3- and H19-overexpressing GH3 cells were seeded to six-well plates with 500 cells per well and cultured separately with the normal medium, lentivirus supernatant, and H19-overxpression supernatant for 14 d, stained with crystal violet, and counted for the number of colonies. (C) The H19 expression level in the four groups was determined, and the H19 RNA level was detected by qRT-PCR and normalized to β-actin. (D) The H19 low expression cell medium promotes GH3 cell proliferation in vitro. For 3 d, cell viability was periodically measured with an MTS assay (n = 3). *P < 0.05.