Polo-like kinase 1,a new therapeutic target in hepatocellular carcinoma

作     者：Wei Chuen Mok Shanthi Wasser Theresa Tan Seng Gee Lim 

作者机构：Institute of Molecular and Cell BiologyAgency for ScienceTechnology and ResearchSingapore 138673Singapore Department of BiochemistryYong Loo Lin School of MedicineNational University of SingaporeSingapore 117597Singapore Department of Gastroenterology and HepatologyYong Loo Lin School of MedicineNational University Health SystemSingapore 117597Singapore Department of MedicineNational University of SingaporeSingapore 119074Singapore 

出 版 物：《World Journal of Gastroenterology》 (世界胃肠病学杂志（英文版）)

年 卷 期：2012年第18卷第27期

页      面：3527-3536页

核心收录：

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

基　　金：Supported by The National University of Singapore Grants No.R-172-000-001-731 and No.R-172-000-024-731 

主　　题：RNA Polo-like kinase 1 Apoptosis Endonu-clease G Forkhead box transcription factors Nude mice 

摘      要：AIM： To investigate the role of polo-like kinase 1 （PLK1） as a therapeutic target for hepatocellular carcinoma （HCC）. METHODS： PLK1 gene expression was evaluated in HCC tissue and HCC cell lines. Gene knockdown with short-interfering RNA （siRNA） was used to study PLK1 gene and protein expression using real-time reverse transcription polymerase chain reaction （RT-PCR） and Western blotting, and cell proliferation using 3-（4,5-dim ethylthiazol-2-yl）-5-（3-carboxymethoxyphenyl）-2（4-sulf ophenyl）-2H-tetrazolium （MTS） and bromodeoxyuridine （BrdU） assays. Apoptosis was evaluated using the terminal deoxynucleotidyl transferase dUTP nick end label- ing （TUNEL） assay, and caspase-inhibition assay. Huh-7 cells were transplanted into nude mice and co-cultured with PLK1 siRNA or control siRNA, and tumor progres- sion was compared with controls. RESULTS： RT-PCR showed that PLK1 was overexpre- ssed 12-fold in tumor samples compared with controls, and also was overexpressed in Huh-7 cells, siRNA against PLK1 showed a reduction in PLK1 gene and protein expression of up to 96% in Huh-7 cells, and a reduction in cell proliferation by 68% and 92% in MTS and BrdU cell proliferation assays, respectively. There was a 3-fold increase in apoptosis events, and TUNEL staining and caspase-3 assays suggested that this was caspase-independent. The pan-caspase inhibitor Z-VAD-FMK was unable to rescue the apoptotic cells. Immnofluorescence co-localized endonuclease-G to fragmented chromosomes, implicating it in apoptosis. Huh-7 cells transplanted subcutaneously into nude mice showed tumor regression in siPLKl-treated mice, but not in controls. CONCLUSION： Knockdown of PLK1 overexpression in HCC was shown to be a potential therapeutic target, leading to apoptosis through the endonuclease-G path- way.