Mechanism Investigation on Influence of MAP4K4 on Biological Activity of Hepatoma Carcinoma Cell

Objective To study the preliminary mechanism of the influence of MAP4K4 on biological activity (cell proliferation，cell clone，cell cycle and cell apoptosis) of hepatoma carcinoma cell(HCC). Methods The expressions of MAP4K4 protein in HepG2，Hep3B，Huh7 and SMMC-7721 were detected to select the highest expressed cell for RNAi experiment.siRNA targeted MAP4K4 (0-HepG2-pGCSil-U6，1-pSilMAP4K4-1 ，2-pSilMAP4K4-2，3-pSilMAP4K4-3) was transfected into hepatoma carcinoma cell and the interfering efficiency was detected through QRT-PCR and Western blot: Biological activity of HCC was analyzed by WST-8 cell proliferation test，flat plate clone formation test，cell cycle test and apoptosis test.To further explore the possible mechanism of MAP4K4 in HCC，the different expression genes between the highest-transfection group and the control group were researched by TOLL-like receptor signaling associated gene chip. Results The expression level of MAP4K4 in cell lines was: HepG2> Hep3B>Huh-7 > SMMC7721.The inhibition rate of MAP4K4 siRNA exceeded 50%.After interference，the cell proliferation and cloning efficiencies were decreased obviously compared to the control group.Cell cycle was blocked at S、G2 phase and the percentage of apoptotic was increased.The upstream genes (TLR3，TLR4，TLR5，TLR6，TLR7，TLR8，MyD88，IRAK，TRAF6，TIRAP) and downstream genes(MAP3K7 and MKK3)were down-regulated markedly. Conclusion MAP4K4 gene knockdown could arrest cell cycle and then inhibit proliferation of HCC.The mechanism might be associated with NF- κB and JNK signal pathway.