Objective To study the role of the outer membrane protein Rmp of Neisseria gonor-rhoeae strain in immunosuppression and the strategy of eliminating it .Methods The rmp gene of Neisseria gonorrhoeae strain was amplified by PCR and inserted into pMD 19-T vector .The recombinant vector pMD 19△rmp∷Kan containing Kan and the 5′-and 3′-flanking regions of rmp (△rmp∷Kan) was constructed by replacing 200 nucleotide residues of pMD 19-rmp with kanamycin resistance gene Kan and transformed into Neisseria gonorrhoeae WHO-A strain.PCR and Western blot assay were used to screen and identify the re-combinant mutant strains that could not express Rmp .Mice were immunized with mutant strains and bacteri-cidal activities of the immune sera were detected by antibody-mediated complement-dependent cytotoxicity assay.Results The mutant strains that could not encode Rmp were successfully constructed .Antibodies in-duced by mutant strains showed stronger bactericidal activity against Neisseria gonorrhoeae in comparison with those induced by wild strains .Conclusion The recombinant Neisseria gonorrhoeae strain with rmp gene de-letion might eliminate the immunosuppressive effects of Rmp expressed in wild gonococcal strains , which provides a reference for further development of novel live attenuated whole-cell vaccines of Neisseria gonor-rhoeae.

Objective To detect the clinical pathogenic bacteria and antimicrobial-resistant genes quickly and sensitively using DNA chip.Methods Based on the analysis of 23S rRNA gene se- quences and other genes sequences associated with antimicrobial resistance(SHV＜CTX_M),oligo nucleotide microarray was designed according to different bacteria and antimicrobial-resistant genes. The DNA fragments were amplified by labeling Cy5 fluorescence and detect clinical pathogenic bacte- rias and antimicrobial-resistant genes by hybridization.Results The result of detection(10~3-10~6 bac- teria/ml)was consistent with that of some documents in domestic and overseas under ideal circum- stances of detecting bacteria genomic DNA by the Reagent Box.And it was specific and reproducible when the detection system were evaluated with some clinical isolates and drug-resistant standard strain.DNA chip could identify 16 species and 7 generics including common diverse clinical pathogenic bacteria,and could detect the drug-resistant of extended spectrum?lactamase gene simultaneously. Conclusions The methods that we have established DNA chip is a sensitive,specific and reproducable tool for supplying routine methods.

Objective The invasion and metastasis of colon cancer often leads to treatment failure and mortality in patients . Our research is to investigate the influence of FoxM 1 to malignant human colon cancer line . Methods In two human colon cancer lines, the protein and mRNA expression levels of FoxM 1 were analyzed with the application of RT-PCR and Western blot , from which high-expressed HT-29 and low-expressed HCT-116 were determined.The expression of FoxM1 was down-regulated by RNA interfering in HT-29 and up-regulated by constructing overexpression transgenic line in HCT-116.The proliferation of the above cells was assayed by healing method;while the metastasis and invasion ability were examined by Transwell chamber assay . Results Two colon cancer lines were selected with high-expression or low-expression of FoxM1 separately named HT-29 and HCT-116.Application of PEX-2-FoxM1 raised after HCT-116 cells express FoxM1, cell scratches in HCT-116 experimetal group ([70.92 ±1.48]%) compared with HCT-116 control group([16.92 ±4.05]%)and HCT-116 blank control group([16.66 ±2.63]%) will markedly enhance its capabil-ity of healing (P<0.05), Transwell Chambers in membrane cells in HCT-116 experimetal group (186.0 ±6.8) compared with HCT-116 control group(42.0 ±2.0) and HCT-116 blank control grou (37.0 ± 2.2)was increased (P<0.05).On the other hand, the applied pG-PH-shFoxM1 can reduce FoxM1 expression in HT-29 cell, cell scrat-ches healing ability in HT-29 experimetal group ( [ 10 .37 ± 3.86]%) compared with HT-29 control group([34.63 ±2.35]%)and HT-29 blank control group([67.36 ±2.61]%) decreased significantly (P<0.05), Transwell Chambers in membrane cells in HT-29 experimetal group (53.0 ±1.8)compared with HT-29 control group(95.0 ±2.2)and HT-29 blank control grou(118.0 ±4.0) was also reduced (P<0.05). Conclusion The expression of FoxM1 is in close relation to the invasion and metastasis of CRC .The fact that the siRNA interfering FoxM1 could effectively inhibit the proliferation, metastasis and invasion, suggesting FoxM1 could po-tentially be a new molecular target for inhibiting the proliferation of human colon cancer line .

OBJECTIVETo study the methylation changes in promoter CpG islands induced by low-dose X-ray radiation (LDR).

METHODSTwenty male BALB/c mice were randomly divided into control and fractionated radiation group exposed to 6 MV X-ray for 10 days (0.05 Gy/day). All the mice were sacrificed 2 h after the last radiation on day 10, and blood samples were collected for detecting DNA methylation changes using Roche-NimbleGen mouse DNA methylation 3×720K Promoter Plus CpG Island Array. MeDIP-qPCR was used to further validate the methylation status of specific genes.

RESULTSA total of 811 genes were found to show specific hypermethylation in fractional radiation group as compared with the control group, involving almost all the main biological processes by GO analysis. Eight candidate genes (Rad23b, Tdg, Ccnd1, Ddit3, Llgl1, Rasl11a, Tbx2, and Slc6a15) were confirmed to be hypermethylated in LDR samples by MeDIP-qPCR, consistent with the results of the methylation chip study.

CONCLUSIONLDR induces promoter hypermethylation on specific genes, which may contribute to radiation-induced pathogenesis.

Animals ; CpG Islands ; radiation effects ; DNA Methylation ; Dose-Response Relationship, Radiation ; Genome ; Male ; Mice ; Mice, Inbred BALB C ; X-Rays