XRCC4, which is inhibited by PFDA, regulates DNA damage repair and cell chemosensitivity.

The mechanism of environmental pollution promoting gastric cancer incidence and difficulty of treatment is not fully understood. In the present article, perfluorodecanoic acid (PFDA), a common persistent environmental pollutant, was used to treat the gastric cell lines and mice to test its genotoxicity. The γ-H2AX immunoblot and plasmid fragment PCR results showed that PFDA had a promotion effect on the DNA double-strand breaks (DSBs) in human and mouse cells. Subsequent results showed that PFDA significantly altered the sensitivity of cells to chemotherapy. Microarray data showed that the expressions of some important DNA repair genes were changed. Further investigation discovered that PFDA inhibition of DNA repair was mediated by X-ray repair cross complementing 4 (XRCC4). The cells deficient in XRCC4 generally exhibited reduced proliferation and premature aging in culture; however, our results indicated that PFDA induced p53 inhibition rescued cells from the apoptosis that was triggered by nonhomologous end-joining (NHEJ) inactivation, and overexpression of p53 expression in PFDA-treated cells enhanced their apoptosis. Finally, T-cell specific factor 4 was suggested by the results as an upstream regulator of XRCC4. This article revealed for the first time that perfluorinated chemicals affect chemotherapeutic sensitivity and the NHEJ pathway, and p53 reduction rescues cells from death.

MicroRNA-212 inhibits proliferation of gastric cancer by directly repressing retinoblastoma binding protein 2.

Retinoblastoma binding protein 2 (RBP2), a newly found histone demethylase, is overexpressed in gastric cancer. We examined the upstream regulatory mechanism of RBP2 at the microRNA (miRNA) level and the role in gastric carcinogenesis. We used bioinformatics to predict that microRNA-212 (miR-212) might be a direct upstream regulator of RBP2 and verified the regulation in gastric epithelial-derived cell lines. Overexpression of miR-212 significantly inhibited the expression levels of RBP2, whereas knockdown of miR-212 promoted RBP2 expression. Furthermore, we identified the putative miR-212 targeting sequence in the RBP2 3' UTR by luciferase assay. MiR-212 inhibited the colony formation ability of cells by repressing RBP2 expression and increasing that of P21(CIP1) and P27(kip1), both critical in cell cycle arrest. In addition, the expression of RBP2 and miR-212 in tumor tissue and matched normal tissue from 18 patients further supported the results in vivo. MiR-212 directly regulates the expression of RBP2 and inhibits cell growth in gastric cancer, which may provide new clues to treatment.

Optimized codon usage enhances the expression and immunogenicity of DNA vaccine encoding the HPV 6b E7 gene / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To analyze the influence of optimal codon usage on the expression levels and immunogenicity of DNA vaccines, encoding the human papillomavirus type 6b (HPV 6b) E7 gene.</p><p><b>METHODS</b>The full length E7 gene of HPV 6b was modified to substitute human preferred codon for rarely used codon, and three mutations were introduced into the pRB binding site of HPV 6b E7 to eliminate its transformation potential. The codon optimized and mutated E7 gene (hu-mE7) were cloned into the Kpn I and EcoR I site of the pcDNA3 mammalian expression vector, the in vitro expression of the hu-mE7 gene and the immunogenicity of hu-mE7 DNA vaccine were compared with the wt-E7gene.</p><p><b>RESULTS</b>The in vitro expression of pcDNA3-hu-mE7 was much higher than the classical wt-E7 plasmid in monkey COS-1 cell line. Mice immunized intramuscularly with the pcDNA3-hu-mE7 showed that the codon modified E7 gene induced a stronger IFN-gamma ratios than the wt-E7 gene.</p><p><b>CONCLUSIONS</b>These results suggest that the optimized codon usage contributes to the enhancement of gene expression and immunogenicity of HPV 6b E7 gene.</p>

Effect of tumor suppressor factor RUNX3 on the expression of apoptosis-related genes in gastric carcinoma cells / 中国病理生理杂志

AIM:To investigate the effect of tumor-suppressor RUNX3 on the transcription of apoptosis-related genes bcl-2,bax,caspase-3,caspase-8,caspase-9 in human gastric carcinoma cells BGC823,and to reveal the apoptosis molecular mechanism promoted by RUNX3. METHODS:The eukaryotic expression vector of human Runx3 gene pcDNA3.1-Runx3 was constructed. pcDNA3.1-Runx3 and blank vector pcDNA3.1 were transfected into BGC823 cells,respectively. After 48 h,the total mRNA and protein were acquired and the expression level of Runx3 was determined by RT-PCR and Western blotting. Then,the mRNA and protein expression of bcl-2,bax,caspase-3,caspase-8 and caspase-9 was determined by RT-PCR and Western blotting. ?-actin was used as a control. RESULTS:The eukaryotic expression vector pcDNA3.1-Runx3 was constructed successfully and transfected into BGC823 cells. RT-PCR and Western blotting confirmed that RUNX3 level was higher in pcDNA3.1-Runx3 transfected BGC823 cells than that in blank vector-transfected cells (P

Establishment of gastric cancerous multi-drug resistance cell stain BGC823/5-FU and its resistance mechanism / 中国病理生理杂志

AIM:To establish the gastric cancerous multidrug resistance cell stain BGC823/5-FU and investigate the relationship between the resistance and the expression of apoptosis related protein Survivin, Bcl-2, Bax and caspase-3. METHODS: Human gastric cancer cell line BGC823 was induced into MDR cell line by intermittent administration of high dose of 5-FU. MTT assay was used to detect the sensitivity of these MDR cells to some chemotherapeutic agents. Flow cytometry was used to detect the expression of P-glucoprotein and the accumulative value of intracellular daunorubicin (DNR) in these MDR cells. Western blotting was used to detect the expression of Survivin, Bcl-2, Bax and caspase-3. RESULTS: The resistance cell stain BGC823/5-FU was established, which possessed the ability of 10.82 fold resistance to 5-FU and cross-resistance to adriamycin, mitomycin C and cisplatin. The expression of P-glucoprotein was higher in BGC823/5-FU cells than that in BGC823 cells, while the accumulative value of intracellular DNR was decreased in BGC823/5-FU cells. Compared with its parent cells, expressions of Bax and caspase-3 in BGC823/5-FU cells were significantly down-regulated, surviving and Bcl-2 were upregulated in BGC823/5-FU cells. CONCLUSION: Gastric cancer cell line BGC823 has been induced into MDR cell line BGC823/5-FU. P-glucoprotein, Survivin, Bcl-2/Bax ratio and caspase-3 may play an important role in MDR of BGC823/5-FU cells.

Antitumor effect of heat-killed lactobacilli adhered to cervical carcinoma cells / 中国病理生理杂志

0.05),but enhanced the expression of CD80,CD86 significantly(P

The mechanism of apoptosis induced by homoharringtonine in HL-60 cells / 中国病理生理杂志

AIM: To study the signal transduction pathway of apoptosis initiation induced by homoharringtonine in HL-60 cells. METHODS: After establishing the model of apoptosis initiation induced by homoharringtonine in HL-60 cells, at the point of apoptosis initiation, molecular caspase-3, Bcl-2, Bax and Fas/FasL were measured with flow cytometry and transmission electron microscope. ERK2 and P38 expression in HL-60 cells were detected by using immunohistochemistry. RESULTS: The model of apoptosis initiation induced by homoharringtonine was established in HL-60 cells. At the point of apoptosis initiation, upregulation of caspase-3 and decrease in Bcl-2/Bax were observed. However, the expression of Fas/FasL did not significantly change. ERK2 expression decreased and P38 expression increased. CONCLUSIONS: Caspase-3, Bcl-2, Bax and mitogen activated protein kinase pathways were involved in signal transduction of apoptosis initiation induced by homoharringtonine in HL-60 cells. [

Gonorrhea and the L- form of Gonococcus Culture / 中华皮肤科杂志

In the paper, we used the culture medium for L-form of gonococcus and dryg sensitivity test to iso late 18 strains of L-form of gonococcus from 84 patients susoected of gonorrhea in clinical practice. Conventional culture medium for gonocuccus were used as control. The result showed that the culture of L-form of gonococcus increased foe rate of detection of gonococcus and decreased under diagnosis. It is helpful in guiding the treatment.

Effect of monocyte/macrophages activated by CpG-oligodeoxynucleotides of bacteria on K562 cells / 中国病理生理杂志

AIM: To study the effect of monocyte/macrophages treated with CpG-oligodeoxynucleotides on leukemic K562 cells. METHODS: The monocytes/macrophages from peripheral blood cells were isolated and induced. The expressions of CD14 and CD16 on monocytes/macrophages were detected by means of flow cytometry. After treated with synthetic CpG-oligodeoxynucleotides, and nonCpG-oligodeoxynucleotides for 24 hours respectively, the inhibiting effect of monocyte/macrophages on K562 cells were detected using MTT method. The secretions of TNF-? and IL-12 from monocytes/macrophages were determined using ELISA method. RESULTS: The monocytes/macrophages treated with CpG-oligodeoxynucleotides enhanced their antitumor effect on K562 cells and increased the secretion levels of TNF-? and IL-12. Whereas, there was no significant difference between antitumor effect and cytokine secretion of the monocytes/macrophages treated with nonCpG-oligodeoxynucleotide. CONCLUSION: CpG-oligodeoxynucleotides increases the cytotoxicity of macrophages on K562 cells in vitro, as well as facilitates the IL-12 and TNF-? secretion. It provides a new approach for immunologic treatment of leukemia.