ABSTRACT
<p><b>OBJECTIVE</b>To establish a quantitative technique for assaying gene methylation in hepatocellular carcinoma (HCC) and evaluate its feasibility for clinical application.</p><p><b>METHODS</b>Following bisulfite modification and PCR amplification, the fragments of CDKN2A and ACTB were cloned into plasmids to generate calibration curves using SYBR Green quantitative PCR, and then these two genes were quantitatively analyzed in 41 cases of HCC specimen.</p><p><b>RESULTS</b>The amplification curve, dissociation curve, calibration curve and electrophoresis analysis showed that SYBR Green fluorescent quantitative PCR could assay 10(2)-10(8) copies/microL of recombinant plasmids with high specificity, high sensitivity and a wide detection range. The tests on 41 cases of HCC specimens further confirmed its feasibility for quantitative analysis of methylation.</p><p><b>CONCLUSION</b>SYBR Green fluorescent PCR is an easy, fast and high-throughout quantitative tool, and it can be used for methylation analysis in basic research or clinical assay.</p>
Subject(s)
Female , Humans , Male , Middle Aged , Actins , Genetics , Biopsy , Calibration , Carcinoma, Hepatocellular , Genetics , Pathology , DNA Methylation , Feasibility Studies , Fluorescence , Genes, p16 , Luminescent Measurements , Nucleic Acid Denaturation , Polymerase Chain Reaction , Methods , Sensitivity and Specificity , Transition TemperatureABSTRACT
Objective To prepare a gene chip for detecting polymorphisms on coding region of genes in hepatocellular carcinoma tissuses. Methods Genes harboring in loss regions with high frequency of hepatocellular carcinoma (HCC) were selected, the related information was inquired and the cSNP sequences were obtained in the SNP database of National Center for Biotechnology Information(NCBI).Then the appropriate primers and oligonucleotide probes were designed according to the SNP sites and the gene chip for the detection of SNPs were constructed. This chip includes 48 cSNPs of 25 hepatocellular carcinoma-related genes. The PCR products labeled by Dig-dUTP were hybridized with cSNP chip. Results The sensitivity, influence of probes and reiteration of the chip were detected. The results indicated that the chip was sensitive about 6?10~(-3) ng/?l. The signal of hybridization was down with lower concentrition of probes. By the chip, 7 of polymorphisms of caspase9 ( rs2308941) C→T and DOK2(rs2242241)T→G, 6 of polymorphisms of EGFL3(rs947345)A →G,caspase9 ( rs2308938)C→G and PHGDH(rs1801955)T→A, 5 of polymorphisms of E2F2(rs3218170) G→A,4 of polymorphisms of MUTYH(rs1140507)T→C and BNIP3L(rs1055806)G→T, 1 of polymorphism of TNFRSF1B (rs1061622)T→G were detected in the tissues of 10 HCC. Samples of caspase9 ( rs2308941G) and ( rs2308941A) were verified by PCR-SSCP and sequencing. Conclusion We prepare the cSNP chip of hepatocellular carcinoma-related genes, which can accelerate the discovery of polymorphic markers on hepatocellular carcinoma.
ABSTRACT
Objective To study the preparation of hepatitis C viruses (HCV) genotyping oligochip and its application in the detection of 76 hepatitis C patients.Methods Oligonucleotide probes and primers were designed in the 5’noncoding region and core region of HCV. The HCV typing chip was prepared by spotting the modified probes onto nylon membrane. Products of the second PCR were labeled with Dig-dUTP. Furthermore, 6 PCR products were sequenced.Results Using the chip,15 subtypes in 11 types of HCV were analyzed.Results of hybridization indicates that 76 hepatitis C patients were all positive and 20 health people were negative.Among 76 patients, 64 cases were 1b type, 11 cases were 2a type and 1 case was 3a type. Mix infection was not found. The results obtained by sequencing 6 samples and chip arraying were the same.Conclusion The HCV genotyping chip could be used in detecting serum HCV RNA and analyzing its genotypes.
ABSTRACT
Objective To detection the methylation of p16INK4A in primary hepatocellular carcinoma, a nested bisulfite sequencing and methylation-specific polymerase chain reaction (BS-MSP) protocol was designed and used.Methods Bisulfite-modified DNA were amplified to evaluate the quality of templates with a pair of bisulfite sequencing primers in the first round of PCR, then subjected to methylation assay with corresponding methylation or unmethylation specific PCR primers.Representative PCR products were sequenced to confirm its correctness.Results 3 of 40 cases (7.5%) were failed to assay due to poor quality of templates, and 29 of 37 cases (78%) were detected p16INK4A methylation.Sequencing results confirmed that templates were correctly amplified.Conclusion BS-MSP technique might be valuable for methylation study on carcinogenesis and clinical assay.