MDM2 antagonist can inhibit tumor growth in hepatocellular carcinoma with different types of p53 in vitro.
OBJECTIVE
Nutlin-3, a selective small-molecule inhibitor of the p53-MDM2 interaction, has been shown to have antitumor activities in various tumors with wild-type p53. However, its effect on hepatocellular carcinoma (HCC) with different types of p53 remains unclear. This study is designed to determine nutlin-3's antitumor efficacy and underlying mechanisms of action in human HCC cells.


METHODS
Cell viability assay, cell cycle analysis, apoptosis assay, western blot, co- immunoprecipitation and siRNA experiments were analyzed in three human HCC cells. Anti-tumoral effects of nutlin-3 targeting the p53 and p73 pathways were evaluated in HCC cell lines.


RESULTS
Nutlin-3 exerted the greatest anti-tumoral effect to three human HCC cells with wild-type p53, mutant p53 and p53-null. Nutlin-3 not only upregulated p53 in HepG2 cells, but also p73 in Huh7 and Hep3B cells, and disrupted p53-MDM2 and p73-MDM2 complexes in HCC cells. The compound inhibited cell proliferation, induced G0/G1 phase arrest, decreased the levels of CyclinD1, CyclinE, CDK2, CDK4, PCNA and E2F-1, and increased the levels of p21 and p27. It also induced apoptosis, increased the Bax/Bcl-2 ratio, then activated caspase-9 and caspase-3.


CONCLUSIONS
Nutlin-3 has significant anticancer effects against human HCC cells, regardless of p53 status, indicating that it is a promising therapy for human hepatocellular carcinoma.
Department of Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China.
Jiabei
J
Wang
Tongsen
T
Zheng
Xi
X
Chen
Xuan
X
Song
Xianzhi
X
Meng
Nishant
N
Bhatta
Shangha
S
Pan
Hongchi
H
Jiang
Lianxin
L
Liu
D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005434:Flow Cytometry; D056945:Hep G2 Cells; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology*; D047468:Immunoprecipitation; D008113:Liver Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010879:Piperazines / Q000494:pharmacology*; D051736:Proto-Oncogene Proteins c-mdm2 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D034622:RNA Interference; D013997:Time Factors; D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D007093:Imidazoles; D009687:Nuclear Proteins; D010879:Piperazines; C495901:TP53 protein, human; C000606460:TP73 protein, human; D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; C482205:nutlin 3; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2