ABSTRACT
<p><b>OBJECTIVE</b>To establish a detection method for HBV drug-resistant mutations related to lamivudine, adefovir and entecavir by optimization and assessment of reverse hybridization system.</p><p><b>METHOD</b>26 degenerated probes covering 10 drug-resistant hotspots of 3 drugs were synthesized and immobilized on the same positively charged nylon membrane. PCR products labeled with digoxigenin were hybridized with corresponding probes. To improve the sensitivity and specificity, 4 reaction steps of reverse hybridization were optimized including the number of labeled digoxigenin, the energy intensity of UV cross-linking, hybridization and stringency wash conditions. To prove the feasibility, the specificity, sensitivity and accuracy of this system were assessed respectively.</p><p><b>RESULT</b>Sensitive and specific results are obtained by the optimization of the following 4 reaction steps: the primers labeled with 3 digoxigenin, energy intensity of UV cross-linking for 1500 x 0.1 mJ/cm², hybridization at 42 degrees C and stringency wash with 0.5 x SSC and 0.1% SDS solution at 44 degrees C for 30 min. In the assessment of system, the majority of probes have high specificity. The quantity of PCR product with a concentration of 10 ng/μl or above can be detected by this method. The concordant rate between reverse hybridization and direct sequencing is 93.9% in the clinical sample test.</p><p><b>CONCLUSION</b>Though the specificity of several probes needs to be improved further, it is a simple, rapid and sensitive method which can detect HBV resistant mutations related to lamivudine, adefovir and entecavir simultaneously. Due to the short distance between 180 and 181, likewise 202 and 204, the sequence of the same probe covers two codon positions, and hybridization will be interfered by each other. To avoid such interference, the possible solution is that probes are designed by arranging and combining various forms of two near codons.</p>
Subject(s)
Humans , DNA, Viral , Genetics , Drug Resistance, Viral , Genetics , Hepatitis B virus , Genetics , Hybridization, Genetic , Mutation , Nucleic Acid Hybridization , Methods , Oligonucleotide Array Sequence Analysis , Sensitivity and SpecificityABSTRACT
<p><b>OBJECTIVES</b>To establish a method for simultaneous detection of HBV resistant mutations associated with three kinds of nucleoside analogues.</p><p><b>METHODS</b>According to 981 HBV complete sequences in GenBank, two pairs of conserved primers labeled with digoxigenin were synthesized to amplify the region of HBV reverse transcriptase. To detect non-synonymous amino acid substitutions associated with lamivudine, adefovir and entecavir, 26 specific oligonucleotide probes covering ten different codon positions, I169T, V173L/G, L180M, A181T/V, T184G, S202I/G, M204V/I, Q215S, N236T and M250V/I/L were synthesized and immobilized on nylon membranes charged positively. The oligonucleotide probes immobilized on nylon membranes were then hybridized with PCR products labeled with digoxigenin to detect three drug-resistant mutations. In order to observe specificity and accuracy of probes, HBV wild-type, resistant reference strains and patients serums were assayed by reverse hybridization technique, respectively.</p><p><b>RESULTS</b>The specific probes of 10 codon positions related to HBV wild-type and resistant reference strains, including I169T, V173L, L180M, A181T, T184G, S202I, M204V, Q215S, N236T, M250V, were distinguished effectively by reverse hybridization method. The results results of 37 samples applicated the method were in accordance with that Of DNA sequencing.</p><p><b>CONCLUSION</b>Reverse hybridization technique can be applied to detect HBV resistant mutations associated with Lamivudine, Adefovir and Entecavir rapidly and accurately.</p>
Subject(s)
Humans , Amino Acid Substitution , Antiviral Agents , Pharmacology , DNA, Viral , Genetics , Drug Resistance, Viral , Genetics , Hepatitis B virus , Genetics , Hepatitis B, Chronic , Virology , Mutation , Nucleic Acid Hybridization , MethodsABSTRACT
The recombined adenovirus DNA was transfected into 293 cells for packing and amplification of replication-deficient Ad-CMV-E6/E7, Ad-K14 -E6/E7 virus was purified by CsCl density gradient centrifugation , recombined adenovirus Ad-CMV-E6/E7, Ad-K14 -E6/E7 were used as experimental group, while pAd-CMV and pAdtrack-K14 were used as control group. Four of them were injected through one main vein of nude mice tail respectively. These mice were then treated with 0.05 mg 17beta-estradiol over 12 weeks. Mice were anaesthesiaed with 2.5% Avertint and the vagina, mammary gland, ovaries and uterus were dissected and fixed in 3.75% paraformaldehyde overnight at 4 degrees C. Paraffin-embedded sections, HE staining and identification of P53 and Bcl-2 protein via immunohistochemistry were performed. The expression of E6/E7 was verified by RT-PCR in different tissue of nude mice. HE staining showed evident hyperplasy in cervix-uterus transformation zone of experimental group 2. The expression of mutant P53 and Bcl-2 were higher than control group via immunohistochemical S-P method in uterus stroma-cell. Western blotting also showed that E6 protein was expressed. The expression of E6/E7 was higher than control group by human cytokeratin promoter 14 and hyperlasy changes were detected in epithelial tissue of cervix-uterus transformation zone.
Subject(s)
Animals , Female , Humans , Mice , Adenoviridae , Genetics , Blotting, Western , Cell Line , Genital Diseases, Female , Pathology , Virology , Genitalia, Female , Pathology , Virology , Immunohistochemistry , Mammary Glands, Animal , Metabolism , Pathology , Mice, Nude , Oncogene Proteins, Viral , Genetics , Metabolism , Ovary , Metabolism , Pathology , Papillomaviridae , Metabolism , Physiology , Papillomavirus E7 Proteins , Proto-Oncogene Proteins c-bcl-2 , Metabolism , Repressor Proteins , Genetics , Metabolism , Reverse Transcriptase Polymerase Chain Reaction , Tumor Suppressor Protein p53 , Metabolism , Uterus , Metabolism , Pathology , Vagina , Metabolism , PathologyABSTRACT
To develop a reverse dot blot assay for rapid detection of HBV genotypes.Specific oligonucleotides probes were desighed and immobilized on nylon membranes.The DNA sample to be tested was PCR-amplified with DIG labeling primers and then hybridized with the immobilized probes.This procedure for detecting HBV genotypes was simple,rapid and specificity.30 specimens in Chongqing area were collected and detected by this method,and results were evaluated using direct sequencing.Results showed that: This new method was applicable to precise detection HBV genotypes for specimen with copies up to 103,and the HBV genotyping results showed that genotype B was the predominant genotype in Chongqing area.