APLN promotes cells proliferation. (A) HKCI-2, HKCI-10, Huh7 and Miha were stably transfected with pcDNA3.1 expression vector carrying APLN cDNA or empty vector (EV). Ectopic expression of APLN was confirmed by RT-PCR (Top panel) and western blot analysis (Bottom panel). (B) PLC5 and HepG2 were transduced with lentiviral carrying APLN-specific shRNAs (shAPLN) or negative control shRNA (shCTL). Knockdown of APLN was confirmed by RT-PCR (Top panel) and western blot analysis (Bottom panel). (C) Ectopic expression of APLN significantly promoted cell viability by MTT assay and increased colony numbers compared to controls. (D) Knockdown of APLN significantly reduced cell viability by MTT assay and decreased colony numbers in PLC5 and HepG2 compared to controls. (E) Knockdown of APLN suppressed the growth of HepG2 xenografts in nude mice (N = 6) compared to controls. Representative images of HepG2 xenografts and tumor weight were shown. Error bars in C and D represent means ± sd from three independent experiments, (* P < 0.05, ** P < 0.01, *** P < 0.001).