Research Paper Volume 15, Issue 10 pp 4304—4318

Figure 2. Roles of USP44 in cell proliferation and the cell cycle in hepatocellular carcinoma (HCC). (A) USP44 expression in various HCC cell lines, including Hep3B, PLC5, MHCC97L, and HepG2. USP44 expression was relatively lower in the HepG2 cell line than in other HCC cell lines. (B) Quantitative real-time PCR analysis validated the overexpression of USP44 after lentiviral infection with either USP44 vector or control vector. (C) The CCK-8 assay showed inhibition of HepG2 cell proliferation after USP44 overexpression. Dashed line = control vector HepG2 cells; solid line = USP44-overexpressing HepG2 cells. (D) Flow cytometry analysis with propidium iodide staining shows cell cycle arrest at the G0/G1 phase in USP44-overexpressing HepG2 cells. (E) USP44 overexpression was associated with reduced colony formation by HepG2 cells. Colony formation was assessed 10 days after 1000 cells were seeded onto a 6-well plate.