Exploration and implementation for the construction of the quaternary teaching system of medical genetics including teaching, practice, research and clinical application.

Medical genetics, the connection between basic and clinical medicine, is a subject with strong applicability and plays important role in modern medical education system. Based on years of teaching experience and during the construction of state-level top quality course, our teaching team has established the quaternary teaching system of medical genetics which includes teaching, practice, research and clinical application. The four elements of the system interpenetrate, complement and reinforce each other. Specifically, classroom teaching is the basics which is further complemented by social practice, improved by research and promoted by clinical application. The quaternary teaching system provides a feasible way to integrate theoretical and clinical courses. After years of implementation, the teaching system has got great effects on the obvious improvement of research ability, social reputation and clinical service capacities of the research team.

[BiOBr promoted the photocatalytic degradation of beta-cypermethrin under visible light].

As a visible light photocatalyst, bismuth oxide bromide (BiOBr) was used to catalyze the degradation of beta-cypermethrin (beta-CP). The photocatalytic degradation of beta-CP was studied with gas chromatography. The effects of pH and catalyst dose on the photocatalytic degradation efficiency were discussed. The oxidization and mineralization of beta-CP were detected by chemical oxygen demand (COD) analyzer. The results showed that beta-CP could be effectively degraded under visible light irradiation using BiOBr as the catalyst. At given experimental conditions, the degradation rate of beta-CP reached 94. 68% after 10 h and the COD removal rate reached 67. 99% after 36 h. With the increase of catalyst dose and pH value, the degradation rate was improved. The photocatalytic oxidation species was determined by peroxidase method and terephthalic acid fluorescence method. These results suggested that the photocatalytic degradation process mainly referred to hydroxyl radical ( OH) mechanism.

[Effects of applying inorganic P and wheat straw on the microbial biomass P and microbial P concentration in a calcareous soil with low concentration available P].

In an incubation test, a calcareous soil with low concentration of available P was amended with KH2PO4 (0, 25, 50, and 100 mg P x kg(-1)) and ground wheat straw (5 g C x kg(-1)), and incubated at 25 degrees C for 90 days. The aim was to investigate the change patterns of soil microbial biomass P and microbial P concentration as well as their relationships with soil available P. The results showed that both soil microbial biomass P and microbial P concentration increased with increasing inorganic P addition, with the maximum being 71.37 and 105.34 mg x kg(-1), respectively. The combined application of inorganic P (except 100 mg P x kg(-1)) and wheat straw decreased the soil microbial biomass P and microbial P concentration, being most obvious at early incubation period. Soil microbial biomass P and microbial P concentration had significant positive correlations (P < 0.05) with soil available P (R2 = 0.26 and 0.40, n = 49, respectively). The applied P could rapidly transform into microbial biomass P. The maximum apparent contribution rate of applied P to microbial biomass P was 71%. The added wheat straw could further improve the apparent contribution rate.

Regulation of survivin and CDK4 by Epstein-Barr virus encoded latent membrane protein 1 in nasopharyngeal carcinoma cell lines.

Latent membrane protein 1 (LMP1), an important protein encoded by Epstein Barr virus (EBV), has been implied to link with the pathogenesis of nasopharyngeal carcinoma (NPC). Its dual effects of increasing cell proliferation and inhibiting cell apoptosis have been confirmed. In this study, we showed that the expression of Survivin and CDK4 protein in CNE-LMP1, a LMP1 positive NPC epithelial cell line, is higher than in LMP1 negative NPC epithelial cell line-CNE1, and the expression is LMP1 dosage-dependent. Although it was reported that Survivin specifically expressed in cell cycle G2/M phase, our studies suggested that LMP1 could promote the expression of Survivin in G0/G1, S and G2/M phase. It also showed that Survivin and CDK4 could be accumulated more in the nuclei triggered by LMP1. More interestingly, Survivin and CDK4 could form a protein complex in the nuclei of CNE-LMP1 rather than in that of CNE1, which demonstrated that the interaction between these two proteins could be promoted by LMP1. These results strongly suggested that the role of LMP1 in the regulation of Survivin and CDK4 may also shed some light on the mechanism research of LMP1 in NPC.

[Cross-talk between c-Jun/Ets1 involved in EB virus-encoded latent membrane protein 1 regulates expression of matrix metalloproteinase-9 in nasopharyngeal carcinoma].

OBJECTIVE: To investigate effect of AP-1 and Ets binding site adjacent to matrix metalloproteinase-9 (MMP-9) promoter on activation of MMP-9 transcription of nasopharyngeal carcinoma cells transfected with EBV-encoded latent membrane protein 1 (LMP1), and to ascertain if cross-talk between c-Jun and Ets1 is involved in LMP1-regulating expression of MMP-9. METHODS: Site-directed mutagenesis technique was used to establish a series of mutants, including MMP-9-CAT-Ets(-540)mt, MMP-9-CAT-AP-1(-533)mt and MMP-9-CAT-AP-1(-533)/Ets(-540)mt. After the mutants were transfected into LMP1-expressing NPC HNE2 cells regulated by Tet-on system (pTet-on-LMP1 HNE2), CAT activity of these mutants were assayed with induction of LMP1. With blockade of c-Jun or Ets1 antisense oligonucleotides, the activity of MMP-9 induced by LMP1 was assayed with gelatin zymography. RESULTS: The CAT activity of MMP-9-Ets(-540)mt-CAT, MMP-9-AP-1(-533)mt-CAT, MMP-9-AP-1(-533)/Ets(-540) mt-CAT decreased significantly compared to MMP-9-CAT wt. After blockade with c-Jun or Ets1 antisense oligonucleotides, activity of MMP-9 induced by LMP1 decreased significantly, especially with combined blockade of c-Jun and Ets1. CONCLUSION: The results suggest that transcription factor AP-1 and Ets play an crucial role in activation of MMP-9 transcription induced by LMP1, and cross-talk between c-Jun/Ets1 is involved in expression of MMP-9 mediated by LMP1.

[EB virus encoded latent membrane protein 1 mediated expression of transcription factor Ets-1 in nasopharyngeal carcinoma cells].

OBJECTIVE: To elucidate the expression of tanscription factor Ets-1 mediated by EB virus encoded latent membrane protein 1 (LMP1) in nasopharyngeal carcinoma (NPC) cells. METHODS: LMP1-expressing NPC HNE2 cells regulated by Tet-on system (pTet-on-LMP1 HNE2) were used. Expression of LMP1 and Ets-1 was observed after induction with Doxycycline (Dox). Expression of Ets-1 mRNA and protein was detected by RT-PCR and Western blot, respectively. The phosphorylation level of Ets-1 protein was examined by co-immunoprecipitation. The DNA binding activity of Ets-1 was detected by electrophoretic-mobility shift assay (EMSA). RESULTS: After induction with Dox in pTet-on-LMP1 HNE2 cells, to some extent, the expression of Ets-1 mRNA and protein, its phosphorylation level and DNA binding activity were increased with enhancement of LMP1 expression. CONCLUSION: LMP1 induces transcriptional activation and expression of Ets-1 which may contribute to the development of NPC.

[Epigallocatechin-3-gallate interferes with EBV-encoding AP-1 signal transduction pathway].

OBJECTIVE: To elucidate the interference effect of Epigallocatechin-3-Gallate (EGCG) on targets of Activator Protein-1 (AP-1) signal transduction pathway activated by EB virus encoded latent membrane protein 1 in nasopharyngeal carcinoma (NPC) cell lines. METHODS: Survival rate of cells was determined by MTT assay. AP-1 and CyclinD1 activation were analyzed by promoter luciferase reporter system. Nuclear translocation of JNK was analyzed by indirect immunofluorescence. Protein expression and phosphorylation were observed by Western blot. RESULTS: EGCG inhibited the survival of CNE1 and CNE-LMP1 cells and the activity of AP-1 caused by LMP1 in CNE-LMP1 cells. EGCG also inhibited the nuclear translocation of JNK and the phosphorylation of c-Jun. It also inhibited cyclinD1 promoter activity and cyclinD1 expression. CONCLUSION: EGCG inhibits AP-1, JNK, c-Jun and cyclinD1 which are key targets on AP-1 signal transduction pathway. The results may explain the molecular mechanism of action of EGCG against nasopharyngeal carcinoma.

Cells in G2/M phase increased in human nasopharyngeal carcinoma cell line by EBV-LMP1 through activation of NF-kappaB and AP-1.

Although previous studies showed that the principal oncoprotein encoded by Epstein-Barr virus, latent membrane protein 1(LMP1), could induce the nasopharyngeal carcinoma cells in G2/M phase increased, little is known about the target molecules and mechanisms. The present study demonstrated that LMP1 could induce the accumulation of p53 protein and upregulate its transactivity in a dose dependent manner, which resulted in the decrease of the kinase activity of cdc2/cyclin B complex and inducing arrest at G2/M phase through the activation of NF-kappaB and AP-1 signaling pathways, and the effect of NF-kappaB was more obvious than that of AP-1. This study provided some significant evidence for further elucidating the molecular mechanisms that LMP1 had effects on the surveillance mechanism of cell cycle and promoting the survival of transformed cells and tumorigenesis.

Cyclin D1 polymorphism and the susceptibility to NPC using DHPLC.

Cyclin D1 is a key cell cycle regulator and a candidate proto-oncogene, whose deregulation has been implicated in pathogenesis of several types of cancers, including NPC. A common A/G polymorphism (A870G) in exon 4 of the cyclin D1 gene, CCND1, is associated with the presence of 2 distinct mRNA transcripts for this G1/S regulatory protein, and CCND1 genotype has been related to some phenotypes of several tumors. To investigate the influence of cyclin D1 genotypes on the genetic susceptibility in humans from Southern China to sporadic nasopharyngeal carcinoma, cyclin D1 genotyping was performed by denaturing high performance liquid chromatography (DHPLC) and DNA sequencing analysis of the PCR products from 84 NPC cases and 91 normal controls. Gene frequency distribution was tested by Hardy-Weinberg equilibrium and comparison of cyclin D1 gene frequencies between the patient and control groups was performed by chi 2 test. Results showed that in NPC patients, the AA genotype of CCND1 was significantly lower (20.24%) than in normal controls (38.46%), and the GG and AG genotypes (GG + AG) were significantly higher in NPC group than in the control group (chi 2 = 6.946, P corrected = 0.016, OR = 2.463, 95% CI = 1.249-4.859). These suggest that the A/G polymorphism of CCND1 was associated with the susceptibility to NPC, and the GG and AG genotypes in NPC patients were significantly higher than those in normal controls.

The Primary Study on Expression and Function of D-Type Cyclins in Nasopharyngeal Carcinoma Cell Lines.

Previous work of the authors established the protein expression spectra of D-type cyclins, and found that there were differential expression in nasopharyngeal carcinoma (NPC) biopsies. Using Western Blotting, aberrant overexpression of the cyclinD1 protein in NPC cell lines is reported. CyclinD2 and cyclinD3, the other members of D-type cyclins, were also detected in NPC cell lines. A comparison of the expression patterns in the cell lines, positive or negative in the latent membrane protein 1 (LMP1) encoded by Epstein-Barr virus, revealed that the expression of D-Type cyclin proteins might be increased by EBV-LMP1. The abundance of these proteins showed characteristic variation consistent with a cell- cycle-dependent oscillation and the peak levels expressed in G1 as analyzed by double-parameter flow cytometry. These data suggest that cyclinD1 is essential for cell cycle progression in G1 and may play a role in NPC carcinogenesis.