The proteomics definition, investigation method and its a pplication in cancer research were simply introduced. Proteomic research is to r eveal the function of genes from an integrated, kinetic and quantitative view at the global protein level, which is an important component of post-genome proje ct. Cancer is a kind of complex disease involved by multi-genes. Proteomic rese arch will be helpful to discover the mechanism of cancer development, to find sp ecial malignant tumor markers and targets of drug treatment.

Objective It was designed to investigate the relationship between the productions of p16 and Rb genes expression and gastric carcinogenesis and evaluate the correlation between the expression of p16 and Rb genes in gastric carcinoma.Methods The expression of P16 and Rb proteins was examined in gastric carcinoma and precancerous lesion and normal gastric mucosa by streptavidin-peroxidase immunohistochemical method (S-P).Results The positive rates of P16 and Rb proteins expression showed as below: There were 96 25%(77/80) and 98 75%(79/80) in normal gastric mucosa, 92 00%(46/50) and 80 00%(40/50) in atypical hyperplasia gastric mucosa and 47 54%(58/122) and 59 84%(73/122) in gastric carcinoma respectively. The positive rates of P16 and Rb proteins expression in gastric carcinoma were significantly lower than that in normal gastric mucosa and atypical hyperplasia gastric mucosa (P

Laryngeal carcinoma related gene 1(LCRG1) is a candidate tumor suppressor gene of Laryngeal carcinoma. To further investigate its transcriptional regulation, the transcriptional start sites for LCRG1 gene have been identified by 5′ RACE (rapid amplification of cDNA ends) based on the bioinformation analysis of LCRG1. Then eleven luciferase expression vectors which contained potential human LCRG1 gene promoter were constructed. Luciferase reporter assay indicated that LCRG1 promoter region was mainly located in -169～+127 region nearby the major transcriptional start site. These results suggested that the region (-169～+127) includes an essential promoter for human LCRG1 gene transcription.

Objective To investigate the methylation status of 14-3-3σ promoter in nasopharyngeal carcinoma cell lines and the influence of de-methylation treatment on 14-3-3σ expression. Methods Methylation status of 14-3-3σ gene promoter and 14-3-3σ mRNA expression were detected by methylation specific PCR (MSP) and RT-PCR in nasopharyngeal carcinoma cell lines CNE1, CNE2,5-8F,6-10B and immortalized nonneoplastic human nasopharyngeal epithelial cell line, NP69. Four nasopharyngeal carcinoma cell lines were treated with 5-asa-2' -deoxycytidine(5-aza-2dC) in different concentration for 72 h, then 14-3-3σ promoter meth-ylation status and m RNA expression were assessed, and western-blot was performed to detect the expression of 14-3-3σ protein. Results 14-3-3σ promoter methylation was detected by MSP in all of the four nasopharyn-geal carcinoma cell lines untreated by 5-aza-2dC whereas not in the treated ones or the immortalized human na-sopharyngeal epithelial cell line, NP69. Accordingly, 14-3-3σ mRNA expression was significantly discounted in untreated nasopharyngeal carcinoma cell lines as compared with NP69. 5-aza-2dC treatment dose-depend-ently reversed 14-3-3σ promoter methylation status and consequently upregulated the expression of 14-3-3σmRNA and protein in 4 nasopharyngeal carcinoma cell lines. High-differentiated CNE1 was more sensitive to 5-aza-2dC than lowly-differentiated CNE2, 5-8F and 6-10B. Conclusion Promoter methylation directly leads to decreased 14-3-3σ gene expression in nasopharyngeal carcinoma cell lines, and 14-3-3σ promoter de-methylation perhaps indicates a new target for nasopharyngeal carcinoma treatment.

Objective To investigate the biological significance of differentially expressed proteins from human primary lung adenocarcinoma with lymph node metastasis adenocarcinoma (LNM AdC) and without metastasis (non-LNM AdC) according to clinical diagnosis of lymph node metastasis and distant metastasis,with bioinformatics approach.Methods Cytoscape software was used to analyze a functional enrichment analysis and a protein-protein interaction network from differentially expressed proteins from LNM AdC and non-LNM AdC.Results The top biological processes were related to glucose catabolic process,hexose catabolic process,monosaccharide catabolic process,alcohol catabolic process,and cellular carbohydrate catabolic process.The top molecular functions were related to phospholipase inhibitor activity,lipase inhibitor activity,calcium-dependent phospholipid binding,phosphlipase A2 inhibitor activity,and lipid binding.A protein-protein interaction network of differentially expressed proteins was generated with literature data.Conclusions This bioinformatics analysis demonstrated that glucose catabolic process,alcohol catabolic process,calcium-dependent phospholipid binding,phosphlipase A2 inhibitor activity,ACTB,ANXA1,ANXA2,ANXA3,VCP,NPM1,KRT1,and SUMO4 are significantly associated with a lung adenocarcinoma.These network data provide new insights into the metastasis mechanisms of human lung adenocarcinoma.

AIM: To investigate the effect of ethanol and chemical carcinogen N,N'-dinitrosopiperazine(DNP) on the exogenous expression of CYP2E1.METHODS: Exogenous hCYP2E1 was introduced into NIH3T3 mediated by lipofectamine. Then the integration of exogenous gene was showed by Southemrn blot. After treated with different concentration of ethanol and DNP,RT-PCR and Western blotting were used to analyze the expression change of hCYP2E1 in NIH 3T3. RESULTS: Two cell clones with integration and stable expression of exogenous hCYP2E1 were obtained. The RT-PCR and Western blotting showed that human CYP2E1 mRNA and protein expression was enhanced with increase in ethanol and DNP concentration. CONCLUSION: Exogenous expression of hCYP2E1 was steadily induced by ethanol and DNP. The mechanism may be due to the activation of its transcription. The DNP carcinogenesis might be related to its in situ activation by CYP2E1.

LCRG1(laryngeal carcinoma related gene1,LCRG1),a new candidate tumor suppressor gene of laryngeal carcinoma.However,it is known little about the possible regulatory mechanisms of LCRG1 gene expression.Restriction endonuclease digestion was used to obtain a set of the 5',or 3'deletion mutants from the region(-169～+127) of the LCRG1 gene.It has been found that the minimal promoter of the LCRG1 gene is mapped at the region from-169～-57.Linker scanning mutational analysis in the region(-169～+127) of the LCRG1 gene was used to identify the crucial cis-elements within the promoter region,The key cis-elements are within the region from-137～-122.SP1,E2F1/DP1,EKLF and ZF9 transcription factor binding site sites were predicted in the region by bioinformatics analysis.Co-transfection with each of a panel of the expression plasmids of the known transcription factors with the relevant reporter construct indicates Sp1 is potent transcription factor for enhancement of the promoter activity,SP1 can also up-regulate the endogenous expression of LCRG1 gene.Electrophoretic mobility shift assay(EMSA) was applied to verify that the key cis-elements of LCRG1 gene exist sequence of Sp1 binding sites.The findings,which showed that the key cis-elements within the region from 137～-122 play an important role in expression of the LCRG1 gene,provide a novel evidence for further study of the function of LCRG1 gene.

Objectives To establish the two-dimensional electrophoresis(2-DE)profile of cell. Secreted proteins.Difierential expression profiling of fibroblast cell secreted proteins between nasopharyngeal carcinoma and normal nasopharyngeal tissue was analyzed.Methods Five tissue specimens each from patients with nasopharyngeal carcinoma and nasal polyp were collected individually.Fibroblast eells from above-mentioned tissue were cultured in serum-free medium,and cell-secreted proteins from the cultured medium were harvested by uhrafihration concentration and desalination.Samples were analyzed by 2-DE,and the differentially expressed proteins were analyzed and identified by matrix-assisted laser desorption/ionization time of flight mass spectrometry.Galectin-1 wa8 analyzed by EUSA test.Results 2-DE diagram of fibroblast cell-secreted proteins Was constructed.1 8 protein spots displayed quantitative changes in expression,and 11 protein spots among them were identified by mass speetrometrv.3 proteins including cystatin C,complement subcomponent C1S precursor,heterogeneous nuclear ribonueleoprotein A1 were down-regulated in the cultured medium of nasopharyngeal carcinoma associated fibroblast cells(CAFs). Nevertheless,the rest cell-secreted proteins including galectin-1,14-3-3 protein sigma,eathepsin L and etc,were up-regulated.Meanwhile,the expression of galectin-1 in the cultured medium was also analyzed and Its results were compared between CAFs and the normal fibroblast cells by ELISA.There Was statistical significance difference between them,and galectin-1 was up-regulated in the cIlltured medium of CAFs.Conclusions The changes of fibroblast cell-secreted proteins during nasopharyngeal carcinogenesi8 are analyzed by 2-DE analysis.The variation of pattern of secreted proteins is involved in signal transduction,protein synthesis,degradation and other pathways.CAFs may regulate tumor microenvironment by the abeve-mentioned pathways,and influence nasopharyngeal carcinogenesis,progress,invasion and metastasis.This study provided experimental basis for the eell secreted proteomics studv in future.

Objective In order to investigate the effect of SH2B1 on leptin signal transduction JAK2/IRS2 and its biological function.Methods Vitro kinase assay and Western blot were used to analyse tyrosine phosphorylatin of key molecule JAK2 and insulin receptor substrate-2 (IRS2). ELISA was used to measure the plasma leptin levels in mice. The postnatal growth of mice was monitored over 27 weeks. Results SH2B1 dramatically enhanced the leptin-stimulated tyrosine phosphorylation of JAK2 and IRS2 in HEK293 cells stably expressing LRb (HEK239~(LRb)). Leptin-stimulated activation of hypothalamic JAK2 and phosphorylation of hyphothalamic IRS2 were significantly impaired in SH2B1~(-/-) mice. The deletion of SH2B1 led to leptin resistance,and fasting and randomly fed plasma leptin levels were respectively 3.2 times and 5.1 times higher in SH2B1~(-/-) males than wild-type littermates at 15 weeks of age. SH2B1~(-/-) males gained body weight rapidly and exceeded wild-type littermates from 5~(th) week. SH2B1(-/-) (at 21 weeks) was approximately twice heavier than wild-type littermates.Conclusion SH2B1 is an endogenous enhancer of leptin sensitivity and required for maintaining normal bodyweight in mice via leptin JAK2/IRS2 pathway.

The molecular techniques were used to analyse tyrosine phosphorylation of JAK2 and STAT3 in leptin receptor overpression cell lines and SH2-Bβ knockout (SH2-Bβ-/-) mice. The serum level of leptin in SH2-Bβ mice was measured by ELISA. The results showed that SH2-Bβ dramatically enhanced the leptin-stimulated tyrosine phosphorylation of JAK2 and STAT3 in vitro. Leptin-stimulated activation of JAK2 and phosphorylation of STAT3 were significantly impaired in hypothalamus of SH2-Bβ-/- mice. The fasting and postprandial serum levels of leptin and body weight were markedly increased in SH2-Bβ-/- mice. Therefore, SH2-Bβ is an endogenous enhancer of leptin sensitivity and regulates body weight via leptin/ JAK2/STAT3 pathway.