Targeted ribonuclease can inhibit replication of hepatitis B virus

AIM: To study the effect of a novel targeted ribonuclease(TN), the fusion protein of HBVc and human eosinophil-derived neurotoxin (hEDN), on the HBV replication in vitro.METHODS: The gene encoding the targeted ribonucleasewas cloned into pcDNA3.1 (-) to form recombinant eukaryoticexpression vector p/TN. Control plasmids, including p/hEDN,p/HBVc, and p/TNmut in which a Lys113→Arg mutation wasintroduced by sequential PCR to eliminate the ribonucleaseactivity of hEDN, were also constructed. Liposome-mediatedtransfection of 2.2.15 cells by p/TN, p/TNmut, p/hEDN, p/HBVc, and pcDNA3.1 (-), or mock transfection wasperformed. After that, RT-PCR was used to verify thetransgene expression. Morphology of the transfected cellswas observed and MTT assay was performed to detect thecytotoxicity of transgene expression. Concentration of HBsAgin the supernatant of the transfected cells was measuredusing solid-phase radioimmunoassay.RESULTS: Transgenes were successfully expressed in 2.2.15cells. No obvious cytotoxic effect of transgene expressionon 2.2.15 cells was found. The HBsAg concentration in thep/TN transfected cells was reduced by 58 % compared withthat of mock transfected cells. No such an effect was foundin all other controls.CONCLUSION: The targeted ribonuclease can inhibit HBVreplication in vitro while it has no cytotoxicity on host cells.The targeted ribonuclease may be used as a novel antiviralagent for human HBV infection.

Whole Cag A Gene Amplification of Helicobacter pylori and Its Fingerprinting by Restriction Fragment Length Polymorphism

To setup a method of amplification for the whole Cag A gene of H elicobacter pylori and its fingerprinting by restriction fragm entlength polym orphism(RFL P) ,nested PCR was employed in com bination with TD- PCR to am plify the gene and Eco RΙ and Hind were used to generate the RFL P fingerprinting.Target DNA fragm ents from 13of2 0 samples were successfully amplified and the relevant RFL P fingerprintings were obtained.It is concluded thatthe m ethod can be used to amplify the whole Cag A gene and Cag A gene has apparent diversity of RFL P profile.

Expression of Matrix Metalloproteinase-7 in Serous Ovarian Tumors

Objective:To explore the expression of matrix metalloproteinase-7 in serous ovarian tumors. Methods: Expression of MMP- 1 in 6 normal ovaries, 12 serous cystadenomas of ovary, 6 borderline cystadenomas of ovary, and 22 serous cystadenocarcinomas of ovary were studied by immunohistoc/temical SP staining. Results: No expression of MMP- 1 was detected in normal ovaries. In most serous ovarian tumors, expression of MMP-7 was detected in both the cytoplasm of tumor cells and stroma, although it was reported in other tumors that MMP- 7 was mainly expressed in the cytoplasm of tumor cells. The expression level of MMP-7 in the cytoplasm of tumor cells was statistically insignificant between serous cystadenomas of ovary, borderline cystadenomas of ovary, and serous cystadenocarcinomas of ovary. But in the stroma, the expression level of MMP-7 in borderline cystadenomas of ovary and serous cystadenocarcinomas of ovary was significantly higher than that in serous cystadenomas of ovary (P<0. 05). In borderline cystadenomas and serous cystadenocarcinomas of ovary, expression of MMP-7 could also be detected in the nuclei of some tumor cells. Conclusion: MMP-7 may play an important role in the progression of serous ovarian tumors.