Recent progress on SELEX and its applications / 病毒学报

SELEX technology (Systematic Evolution of Ligand by Exponential Enrichment) is a new in vitro screening technology appeared and developed in the past 20 years. SELEX integrate library technology and screening techniques, screening a nucleic acid molecule from nucleic acid library by ligand-aptamer interaction. Similar to the antibodies, aptamers bind with the specific target substance. SELEX screening technology develops rapidly, and aptamer have been widely applied in biomedical field. This article briefly-overviewed the progress and its applications of SELEX technology in recent years.

A novel SELEX method for screening of HIV-1 P24 antigen / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To screen aptamers that can bind P24 antigen tightly and specificly, and verify its specificity and affinity.</p><p><b>METHODS</b>Polycarbonate PCR plate was coated with P24 antigen and SELEX technology was used to screen aptamer on the PCR plate. The primary and secondary structure of these aptamers was analyzed by software. Through HRP labeled streptavidin and biotin labeled aptamers, the affinity and specificity of obtained aptamers were verified by ELISA.</p><p><b>RESULTS</b>The polycarbonate PCR plate could be coated with P24 antigen. Electrophoretic analysis showed the aptamers had been enriched. Sequence aligment analysis showed that these aptamers have consensus sequence and their apatial structure was multiple; ELISA verified that aptamers had high affinity with P24 antigen.</p><p><b>CONCLUSION</b>A simple method was established for screening aptamers that can bind HIV-1 P24 antigen specificly and tightly.</p>

Expression of peroxiredoxin III in cervical lesions / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the expression feature of peroxiredoxin III in cervical lesions and to further understand the mechanism for cervical cancer development/progression.</p><p><b>METHODS</b>Expression of peroxiredoxin III was immunohistochemically detected in cervical cancer. In addition, cervical epithelia were transfected with recombinant adeno-associated virus vector containing human papillomavirus 16 E6/E7 and peroxiredoxin III expression was detected by quantitative real time PCR and Western blotting.</p><p><b>RESULTS</b>Peroxiredoxin III was significantly up-regulated in cervical cancer tissues. Nevertheless, expression of peroxiredoxin III remained unchanged in cervical epithelial cells after transfection.</p><p><b>CONCLUSION</b>It seems that Prx III is not related to cervical cancer initiation. Up-regulation of peroxiredoxin III in cervical cancer might be an active response to oxidative stress in malignant cells, which protects against oxidatiton-induced apoptosis.</p>

Improve on serological diagnosis method of nasopharyngeal carcinoma / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To improve the existing serological early diagnosis method of nasopharyngeal carcinoma by improve the detection sensitivity.</p><p><b>METHODS</b>The samples of 294 serum specimen from the prevention and treatment of nasopharyngeal cancer model base, involving 106 serum specimen from the patients suffering from nasopharyngeal cancer and 188 from the healthy testers. IgA/VCA antibody and IgA/EA antibody of the serums are tested by Streptavidin-biotin-antibody immunoenzymatic test and normal traditional enzyme methods, SPSS statistical software is used to analyse the test results with chi2 test and t test.</p><p><b>RESULTS</b>Referring to 106 patients, the sera antibody positive rate tested by Streptavidin-biotin-antibody immunoenzymatic test method is obviously higher than that tested by traditional method; and the t test result of the GMT has significant difference in the two method.</p><p><b>CONCLUSION</b>The modified method can improve the sensitivity of serology testing, ensure the specificity of test results, at the same time, improve the detection rate of nasopharyngeal carcinoma, so it can be applied to the early screen work of nasopharyngeal carcinoma.</p>

A serological survey of Epstein-Barr virus infection in children in Beijing / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To understand the prevalence of Epstein-Barr virus (EBV) infection in urban and rural areas of Beijing using the serological method.</p><p><b>METHODS</b>Totally 589 serum samples were collected from children in Beijing urban and rural areas who were 0--14 years old and tested with Viron-Seron ELISA classic EBV virus capsid antigen IgG antibody (EBV VCA IgG) kit. Optical density of serum samples was obtained at the wavelength of 405 nanometers. Sero-positive or negative samples were determined according to standard curve and cut-off attached in ELISA classic EBV VCA IgG kits. The activity of EBV VCA IgG was calculated by using special formula. The percentage and activity of EBV VCA IgG from Beijing children were compared with SPSS 13.0 between the urban and rural areas.</p><p><b>RESULTS</b>The percentage of EBV VCA IgG seropositive samples was 83.6%, and 80.8% in those from urban and 86.2% in those from rural areas. The peak value of EBV infection was 71% seen among children under the age of 3 years, and in urban area the rate was 67.7%, which was lower than that in the rural area (75.3%), and was 82.5% by the age of 6, which was lower than the data (up to 90%) reported 30 years ago. There was a significant difference in EBV infection rate and VCA IgG activities in children at different ages between urban and rural areas (P < 0.05).</p><p><b>CONCLUSION</b>The rate of EBV infection in children living in urban area was lower by the age of 6 years. The primary infection of EBV occurred late in part of children lived in urban area.</p>

Effect of Nocardia rubra cell wall skeleton (Nr-CWS) on oncogenicity of TC-1 cells and anti-human papillomavirus effect of Nr-CWS in lower genital tract of women / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To detect the effect of Nocardia rubra cell wall skeleton (Nr-CWS) on tumorigenicity induced by TC-1 cells and to clinically study anti-human papillomavirus effect of Nr-CWS in lower genital tract of women.</p><p><b>METHODS</b>Tumor model was established by injecting TC-1 cells subcutaneously in SCID mice, then divided them into 3 groups randomly and injected with isovolumetric physiological saline, 60 micrograms/ml Nr-CWS and 120 micrograms/ml Nr-CWS respectively, the growth of tumors was measured one week later. Nr-CWS was applied on 45 HPV positive women whose TCT test was normal and without cervical erosion 2-3 days after menstruation. HPV was detected again 3 months later to explore the effect of Nr-CWS on HPV infection in female lower genital tract.</p><p><b>RESULTS</b>The animal experiment showed the weight of transplanted tumors in treated group was less than that of control group (chi2=12.5, P= 0.002). The tumor inhibition rate was 59.1 percent and 84.2 percent in the groups treated with Nr-CWS 60 and 120 micrograms/ml Nr-CWS; the results of HPV detection in 23 out of the 45 cases (51.1 percent) became negative after the 3-month treatment; the viral load was reduced in 9, and there was no change in viral load in 13 cases. Significant difference was found between the rates of undetectable viral load and the natural viral disappearance rate (P less than 0.05).</p><p><b>CONCLUSION</b>Nr-CWS has an inhibitory effect to TC-1 cell tumorigenesis and clinical application of Nr-CWS may eliminate the HPV infection in lower genital tract of a considerable proportion of women with HPV infection.</p>

Molecular mechanism of metastasis inhibition of nasopharyngeal carcinoma cell CNE-2L2 induced by reduction of 6A8 alpha-mannosidase expression / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the effect of inhibition of 6A8 alpha-mannosidase expression on adhesiveness among and E-cadherin expression on CNE-2L2 cells, and on metastasis of the tumors from the cells inoculated in nude mice.</p><p><b>METHODS</b>Anchorage-independent adhesion among cells was examined in soft agar culture. E-cadherin expression was studied by immunofluorescence staining, immunohistological staining and RT-PCR. CNE-2L2 cells were subcutaneously inoculated into nude mice. Eight weeks later tumor metastasis was demonstrated by means of histological examination of lung sections.</p><p><b>RESULTS</b>CNE-2L2 cells with suppression of 6A8 alpha-mannosidase expression (AS) became aggregated. E-cadherin expression on wild type cells was very weak. In contrast, it was greatly enhanced on AS cells. The enhancement was detected on both protein and mRNA levels. Lung metastasis of the tumor from inoculated AS cells were heavily inhibited in nude mice.</p><p><b>CONCLUSION</b>Inhibition of 6A8 alpha-mannosidase expression results in enhancement of cell-cell adhesion and of E-cadherin expression on CNE-2L2 cells. Lung metastasis of the tumor grown from AS cell inoculate in nude mice is heavily suppressed.</p>