RESUMO
Objective To establish a real-time fluorescence quantitative methylation assay to investigate the methylation status of GSH-sulphur-transferase P1(GSTP1) gene promoter region in hepatocellular carcinoma(HCC) and to investigate whether which can be used as the early diagnostic indicator of HCC .Methods Ninety-five serum samples were collected from 40 patients with HCC ,30 patients with liver cirrhosis and 25 individuals with healthy physical examination as controls .The methylation level of GSTP1 gene in these serum samples were quantitatively determined by using the real-time fluorescence quantitative methylated spe-cific PCR technique .The receiver-operation characteristic(ROC) curves were adopted to evaluate its diagnostic value for HCC .Re-sults The methylation quantitative level of GSTP1 gene in HCC serum was significantly higher than that in the healthy controls (P<0 .05) .The ROC curve analysis demonstrated that the methylation quantitative analysis of GSTP1 gene could efficiently distin-guish HCC and cirrhosis from healthy controls (AUC=0 .8641) .With the methylation rate of 2% as the critical value for diagno-sing HCC ,its diagnostic specificity was 87 .5% ,the sensitivity was 69 .6% ;the combination detection of serum GSTP1 gene methy-lation and serum AFP could increase the detection rate of HCC to 75% .Conclusion The real-time fluorescence quantitative methyl-ation assay can accurately quantify the methylation level of serum GSTP1 gene ,which has certain application value for the early di-agnosis of HCC .
RESUMO
Objective To seek the specific receptors associated with hepatitis B virus (HBV) adhesion by separating the binding protein of the HBV preS1 region in HepG2 and performing the mass spectrometry .Methods The immunomagnetic bead method was adopted to separate HepG2 membrane protein combined with preS1 peptide fragment and the binding protein was separated by the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) ,then the destination strips was analyzed by LC-MS/MS mass spectrometry and retrieved by the database .Results 16 bands were separated from HepG2 membrane proteins combined with preS1 by SDS-PAGE ;14 kinds of proteins were identified from 6 bands with better repeatability separated from HepG 2 membrane proteins combined with preS1 .Conclusion Protein analyzed by the mass spectrometry is mainly related with the material transport , cellular signal transduction ,antigen presentation ,immune regulation and energy metabolism .