Objective To investigate the significance of K-ras gene status and ras protein expression in immunophenotypic classification of gastric signet ring cell carcinoma.Methods The expression of ras protein in 180 cases of gastric signet-ring cell carcinoma was detected by tissue microarray immunohistochemistry.Meanwhile,the mutation in codon 12,13 of K-ras gene was determined by using PCR-based DNA direct sequencing analysis.Results The rate of ras protein expression was 27.8％.The rate of ras protein expression in intestinal phenotype was significantly higher than those in gastric and gastrointestinal phenotypes(P<0.05).The rate of ras protein expression in cases with lymph node metastasis was significantly higher than those in cases without nodal involvement(P<0.05).The rate of ras protein expression was significantly higher in cases with deeper invasion(P<0.05).The frequency of K-ras gene mutation was 22(12.2％).All of them were found in codon 12.The types of mutation included GGT→AGT(1 case),GGT→TGT(1 case),GGT→GCT(2 cases),GGT→GTT(8 cases)and GGT→GAT(10 cases).K-ras mutation was significantly associated with intestinal phenotype(P<0.05).The rates of ras protein expression in cases with mutational type of K-ras gene was higher than those in cases with wild type(P<0.05).The ras protein expression was positively associated with K-ras gene mutation(r=0.61,P<0.05).Conclusion The ras protein expression is correlated with nodal involvement and invasion.K-ras gene mutation and expression of ras protein is related to phenotypic classification,and they might influence the phenotypic transformation in gastric signet ring cell carcinoma.

AIM: To study the inhibitory effects of nm23-H1 gene on proliferation and invasion of human lung adenocarcinoma A549 cell line. METHODS: Recombinant eukaryotic expression vector pcDNA3.1-nm23-H1 containing full length of human nm23-H1 cDNA was constructed and transfected into a human lung adenocarcinoma A549 cell line by lipofectamine. Cell strain that expressed nm23-H1 stably was screened out by G418 and named pcDNA-nm23-A549. Expression of nm23-H1 was identified by RT-PCR and immunohistochemistry. Growth curves were drawn to detect the inhibitory effects on cell proliferation. Cell cycle of pcDNA-nm23-A549 was examined by flow cytometry. Atomic force microscopy was used to observe the filopodia on the surface of the cells. RESULTS: Introduction of nm23-H1 obviously inhibited the proliferation of A549. Expression of nm23-H1 did not induce apotosis in A549 cells but increased the percentage of phase G_1 cells and decreased phase S cells. Meanwhile, phase G_1 to phase S transition was restrained. Filopodia in the cell surface was much fewer and its structure changed in cells transformed. CONCLUSION: nm23-H1 is capable of inhibiting A549 proliferation and decreasing its metastatic ability, probably by interfering with cell cycle and cell surface structure.

AIM: To construct E. coli expression plasmid of recombinant human NDPK-A with a 6?His tag, optimize the expression condition and identify the activity of the product. METHODS: nm23-H1 was subcloned from plasmid pBVNMH1 to pQE40 which contain 6?His purification tag. The expression condition was modulated in grades to get the optimal expression. We purified protein with the Ni+-NTA affinity chromatography column, identified the immunogenicity of the product with Western blot, and measured the kinases activity with HPLC. In addition, angiogenesis inhibition activity of rhNDPK was identified by CAM. RESULTS: The sequence of nm23-H1 subclone in pQE40 was exactly correct. The expression rate of rhNDPK-A was 49 6%. Purified rhNDPK-A specially recognized the antiserum of NDPK-A. It also inhibited angiogenesis. CONCLUSION: PQE-nm23H1 containing 6?His can express target protein at high level. This purification method is simple than other methods, and the product has the same activity as natural human NDPK-A.

Objective To investigate the effects of lanthanum chloride on proliferation and migration activity of human cervical cancer cells in vitro which may be a new anti-cervical cancer drug and provide experimental data for cervical cancer treatment. Methods HeLa cells cultured in vitro were divided into two groups: experimental group and control group. In experimental group, the cells were respectively treated with lanthanum chloride at different concentrations, 5, 50 and 100 μmol/L, while the cells in the control group were not treated with lanthanum chloride. The cell growth was observed by inverted microscope and the morphology changes of the cells were observed by the laser scanning confocal microscope (LSCM).Proliferation of HeLa cells in the two groups was detected by methyl thiazolyl tetrazolium (MTT) test;apoptosis rate was analyzed by flow cytometry (FCM). Cell migration test was applied to observe the effect of lanthanum chloride on migration. Reverse transcription (RT)-PCR was employed to evaluate the effects of lanthanum chloride on proliferation gene (cyclinD1), anti-apoptosis gene (zinc finger protein A20) and migration-related gene (matrix metalloproteinase 9, MMP-9). Results The status of cell growth was observed under the inverted microscope: with the increased of the lanthanum chloride concentrations, the cell density of reduced, the granule in cytoplasm increased, color intensifying and intercellular space enlarged; some cells became rounding and dead, floating in the culture media; the exfoliated cells increased gradually in the experimental groups. While In the control group, the cells grew adherently, with clear morphology and plump cytoplasm, and adjacent cell grew in lamellar. Observed with LSCM: the nuclear chromatin condensated and marginated with the volume of nuclear decreased in experimental groups. With the increase of the lanthanum chloride concentrations, nuclei in the experimental groups became pyknotic and then underwent karyorrhexis. However, the nuclear of the cells in control group were inact. The growth inhibition rates of lanthanum chloride groups (5, 50, 100 μmol/L) were 24%, 51% and 78%,respectively, in which each was significantly higher than that of the control group (P < 0. 05); the apoptosis rates of lanthanum chloride group were (4. 91 + 0. 39) %, (7. 30 + 0. 71) % and (13.48 + 0. 92) %,respectively, which were all significantly higher than that of the control group [(0. 89 + 0. 11) %, P <0.01]. The migration ability of the cells was also decreased by the treatment of lanthanum chloride, the number of migrated cells in lanthanum chloride groups were 22.2±4. 3, 12. 0±3.2 and 7. 8±2. 6 respectively, which were all significantly lower than that of the control group (41.2±5.4, P < 0. 01). The expression of genes of cyclinD1, A20 and MMP-9, were all decreased by the treatment of lanthanum chloride in a dose-dependent manner. Conclusion Lanthanum chloride can inhibit the proliferation and migration of cervical cancer cells, and induce apoptosis by down-regulating cyclinD1, A20, and MMP-9 expressions in vitro.

Cyanovirin-N (CVN) is an 11 kDa anti-HIV protein originally isolated from extracts of a cyanobacterium, Nostoc ellipsosporum. The protein binds with high affinity to the viral envelope glycoprotein gp120 and irreversibly inactivates diverse HIV strains. A fusion gene consisting of cvn, sumo and 6xHis tag was synthesized by PCR according to the codon bias of Escherichia coli. The fusion protein is expressed in the cytoplasm of E. coli in a soluble form and up to 28% of the total protein. The recombinant CVN was purified to homogeneity by 2 rounds of Ni-NTA affinity chromatography and one round of SUMO protease cleavage. Bioactivity assay demonstrated that SUMO-CVN and CVN bound to gp120 with nanomolar concentration. In addition, CVN showed potent anti-HSV-1 and anti-HIV-1 activities in in vitro cellular assays. Therefore, the 6xHis SUMO fusion expression and purification system provides a better approach for large scale production of CVN for further microbicide development.
Antiviral Agents ; isolation & purification ; metabolism ; pharmacology ; Bacterial Proteins ; biosynthesis ; genetics ; pharmacology ; Carrier Proteins ; biosynthesis ; genetics ; pharmacology ; Escherichia coli ; genetics ; metabolism ; HIV-1 ; drug effects ; Herpesvirus 1, Human ; drug effects ; Recombinant Proteins ; biosynthesis ; genetics ; isolation & purification ; pharmacology