Scientists forced liver cancer cells to make more of a protein called TCF21 and saw that the cells grew slower, moved less, and died more. This was linked to higher levels of a molecule named KISS1 (related to the kisspeptin peptide) and the tumor‑suppressor p53, while a protein that helps tumors spread, MMP‑9, went down.

To explore the impact of transcription factor 21 (TCF21) gene on proliferation, migration and apoptosis in SMMC-7721 hepatocellular carcinoma cell line and the related mechanism. Using Lipofectamine™2000, we stably transfected pcDNA3.1⁺TCF21 and pcDNA3.1⁺ plasmids into SMMC-7721 cells of TCF21 over-expression group and empty vector group, respectively. The untreated cells were set as blank control group. The expression of TCF21 mRNA and protein were investigated by reverse transcription PCR and Western blotting. Cell proliferation ability was detected by MTT assay. Wound healing assay was used to observe cell migration ability. Annexin V-FITC/PI double labeling combined with flow cytometry was applied to determine cell apoptosis rate. Western blotting was performed to examine the expressions of KISS1, P53 and matrix metalloproteinase-9 (MMP-9). TCF21 was over-expressed in TCF21-transfected SMMC-7721 cells. Compared with the control groups, the TCF21 over-expression group showed relatively weakened proliferation ability and significantly inhibited migration ability as well as the increased apoptosis. Western blotting demonstrated that up-regulated TCF21 raised the expressions of KISS1 and p53, and down-regulated MMP-9 level. Tumor-suppressor gene TCF21 could inhibit the proliferation and migration of SMMC-7721 hepatocellular carcinoma cells and promote its apoptosis.