RESUMO
We previously demonstrated that the enhancer of rudimentary homolog (ERH) gene is required for the expression of multiple cell cycle and DNA damage response (DDR) genes. The present study investigated the role of ERH and its target DNA damage repair genes in hepatocellular carcinoma cells. We observed positive correlation between ERH and ataxia telangiectasia and Rad3 related (ATR) expression in liver tissues. Expression of ERH, ATR as well as checkpoint kinase 1 (CHK1) were higher in HCCs than in normal liver tissues. Knocking-down ERH augmented ultraviolet light induced DNA damage in HepG2 cells. ATR protein level is reduced upon ERH depletion as a result of defect in the splicing of ATR mRNA. Consequently, the ATR effector kinase Chk1 failed to be phosphorylated upon ultraviolet light or hydroxyurea treatment in ERH knocked-down HepG2 cells. Finally, we observed Chk1 inhibitor AZD7762 enhanced the effect of doxorubicin on inhibiting growth of HCC cells in vitro and in vivo. This study suggested that ERH regulates the splicing of the DNA damage response proteins ATR in HCC cells, and targeting DNA damage response by Chk1 inhibitor augments chemotherapy to treat HCC cells.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Dano ao DNA , Reparo do DNA , Fatores de Transcrição/metabolismo , Animais , Antibióticos Antineoplásicos/farmacologia , Antibióticos Antineoplásicos/uso terapêutico , Antibióticos Antineoplásicos/toxicidade , Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/genética , Proliferação de Células/efeitos dos fármacos , Quinase 1 do Ponto de Checagem , Dano ao DNA/efeitos da radiação , Sinergismo Farmacológico , Células Hep G2 , Humanos , Fígado/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Quinases/química , Proteínas Quinases/metabolismo , Interferência de RNA , RNA Mensageiro/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Raios UltravioletaRESUMO
OBJECTIVE: Detecting hepatitis B virus large surface protein (HBLP) with serological method to filtrate the occult HBV infection and study the clinical detection strategy. METHODS: Two thousands HBsAg negative stochastic serum samples were collected from the copy tubes in daily work to detect hepatitis B Virus markers (HBVM) with national EHSA regent kits and put them -20 degrees C frostily. The 2000 samples were detected with HBLP and filtrated the positive samples. The HBsAg markers were doubly counterchecked with other two adding kinds of national ELISA regent kits (total 3 kinds) at the filtrated samples. The last samples were doubly tested again with American MONOLISA HBsAg ULTRA regents. HBV DNA levels were quantitative analyzed with fluorescence quantitative PCR (FQ-PCR) and taking the mean results. RESULTS: Fifteen HBLP positive samples were detected out from the 2000 serum samples. We educed the conform negative results from the three kinds of national regents but conform positive results from the American MONOLISA HBsAg ULTRA regents in repeating HBsAg detection at the 15 samples. The HBV DNA FQ-PCR quantitative results were all less than 500 copies/mi and divided into two cases hetween 400-500 copies/nil, three cases 300-400 copies/ml, five cases 200-300 copies/ml, four cases 100-200 copies/ml and one case was less than l00copies/ml. CONCLUSION: The false HBsAg negative results for serum samples are more generally through national regents than through importations and HBLP results mayhe are positive in these samples. Detecting HBLP marker is propitious to filtrate the occult HBV infection. This study provided a kind of serological reference for actively searching for the detecting strategy in occult HBV infection field.
