Objective To investigate the tumor suppressor genes of phlegm DNA in smokers, and analyze the correlation between methylation level of tumor suppressor gene promoter and chronic mucus hypersecretion (CMH). Methods The study recruited the patients who were admitted in the respiratory department during 2013-2016 in this hospital, including 700 cases of urban smokers and 380 cases of rural smokers. Eleven genes commonly silenced by promoter methylation in lung cancer and associated with cancer risk were selected. Methylation specific PCR (MSP) was used in the sputum sample of 700 individuals in the urban smokers cohort. Replication was performed in 380 individuals from the rural smokers cohort. Results CMH was significantly associated with an overall increased number of methylated genes, with SULF2 methylation demonstrating the most consistent association. The association between SULF2 methylation and CMH was significantly increased in males but not in females both in the urban and rural groups (OR=2.73, 95%CI 1.53-4.93, P=0.001; OR=2.96, 95%CI 1.47-5.94, P=0.002, respectively). Furthermore, the association between methylation and CMH was more obvious among 139 male former smokers with persistent CMH compared with current smokers (SULF2, OR=3.64, 95%CI 1.57-8.35, P=0.002). Conclusion These findings demonstrate that especially male former smokers with persistent CMH have markedly increased promoter methylation of lung cancer risk genes and potentially could be at increased risk for lung cancer.
OBJECTIVE: To investigate the effects of basic fibroblast growth factor (bFGF) on the promoter activities of human alpha 1(I) procollagen gene and the interaction between bFGF and transforming growth factor-beta 1 (TGF-beta 1). METHODS: Fibroblasts of the hypertrophic scar and normal skin from a 3-year-old patient were primarily cultured and subcultured in vitro. Both of the fibroblasts were transient transfected with phCOL 2.5, containing -2.5 kb of 5’f lank sequence of human alpha 1(I) procollagen gene and CAT reporter gene by FuGENE transfection reagent; and treated thereafter by 16 ng/ml bFGF, 2 ng/ml TGF-beta 1 and 16 ng/ml bFGF + 2 ng/ml TGF beta 1 for 24 hours. The relative CAT expression values were determined by CAT-ELISA. RESULTS: TGF-beta 1 bly induced the CAT expression level, however, bFGF not only inhibited the basal CAT expression but also reduced the CAT expression up-regulated by TGF-beta 1 in normal skin and hypertrophic scar fibroblasts (P lt; 0.05). CONCLUSION: bFGF can reduce the promoter activities of human alpha 1(I) procollagen gene and antagonize the role of TGF-beta 1 in up-regulating the promoter activities of human alpha 1(I) procollagen gene in normal skin and hyertrophic scar fibroblasts.
ObjectiveTo construct tumor specific tubercle bacillus antigen Ag85A gene lentiviral vector driven by murine telomerase catalytic subunit promoter (PmTERT), paving the way for further research in tumor targeting immuno-gene therapy. MethodsPmTERT was amplified by PCR method, with murine genomic DNA as template. Then, transcriptional activities of PmTERT in various murine and human cell strains were studied by luciferase assay. Ag85A expression lentiviral vectors driven by cytomegalo virus (CMV) promoter and PmTERT respectively (pLVX-Ag85ACMV and pLVX-Ag85A-PmTERT) were constructed with nucleic acid cloning approach. And above recombinants were verified with DNA sequencing and Western blot. ResultsLucifease assay revealed that 331 bp PmTERT cloned in present research had transcriptional activity in murine Lewis lung cancer cells, human lung adenocarcinoma cells A549, and human esophageal cancer cells EC-109, while no transcriptional activity in murine fibroblasts NIH3T3 and human embryo fibroblasts MRC-5. Western blot revealed expression of Ag85A in pLVX-Ag85A-CMV transfected Lewis and NIH3T3 cells, pLVX-Ag85A-PmTERT transfected Lewis cells, no expression in pLVX-Ag85A-PmTERT transfected NIH3T3 cells. ConclusionPmTERT has tumor specific transcriptional activity. Ag85A gene can express selectively in tumor cells, driven by PmTERT.
ObjectiveTo determine the level of CDH1 gene promoter hypermethylation in human gastric carcinoma by establishing MS-PCR method, and analyze retrospectively the possible statistical relationship between CDH1 gene promoter hypermethylation in human gastric carcinoma and HP infection, tumor differentiation, invasion, lymph nodal and distant metastasis, respectively. MethodsThe bisulfite conversion MS-PCR method was adopted to examine the level of CDH1 gene promoter hypermethylation in 40 cases of human gastric carcinoma tissue collected between January 2008 and December 2009. The statistical relationship between CDH1 gene promoter hypermethylation in human gastric carcinoma and HP infection, tumor differentiation, invasion, lymph nodal and distant metastasis were examined respectively with SPSS statistical tools. ResultsThe positive rate of CDH1 gene promoter hypermethylation in gastric carcinomas (67.5%) was higher than that in paired normal gastric mucosae (12.5%), and the difference was significant (P<0.05). In gastric carcinomas, the positive rate of CDH1 gene promoter hypermethylation in well differentiated or moderately differentiated groups (22.2%) was lower than that in poorly differentiated groups (80.6%), and the difference was significant (P<0.05). The positive rate of CDH1 gene promoter hypermethylation in HP positive groups (78.1%) was higher than that in HP negative groups (25.0%), and the difference was significant (P<0.05). ConclusionCDH1 gene promoter hypermethylation may play an important role in the process of tumor carcinogenesis in gastric carcinomas. Meanwhile, the CDH1 gene promoter hypermethylation may lead to poor differentiation in gastric carcinomas. CDH1 gene promoter hypermethylation is related to HP infection in the original gastric carcinomas, which shows that HP may get involved in the process of tumor suppressor gene methylation/inactivation and tumor development process.
Objective To detect the single nucleotide polymorphisms ( SNPs) in the upstream promoter region of chemokine like factor ( CKLF) gene and analyze their possible associations with asthma and asthma-related phenotypes. Methods Direct Sequence of the 1553bp upstream promoter region of CKLF gene was performed in 245 Chinese Han human genomic DNAs ( 119 asthmatics and 126 controls) .The frequencies of alleles, genotypes, and haplotypes were determined and the association of these SNPs with asthma were further analyzed. Results Four novel SNPs, SNP88 ( T gt; C) , SNP196 ( T gt; C) , SNP568 ( C gt;G) , and SNP1047 ( C gt; G) were found in the promoter region of CKLF. The frequency of rare allele was 0. 168 ( SNP88C) , 0. 168 ( SNP196C) , 0. 352 ( SNP568G) and 0. 167 ( SNP1047G) , respectively.Haplotypes, their frequencies and the linkage disequilibrium coefficients between SNPs were constructed.Complete linkage disequilibrium( LDs) were observed between SNP88 and SNP196, SNP88 and SNP1047,as well as SNP196 and SNP1047, respectively ( D′=1. 000, r2 = 1. 000) . SNP568 was in partial LD with the other three SNPs ( r2 = 0. 366) . No association between asthma and the SNPs was observed. Conclusions Four SNPs in the regulatory region of CKLF in Chinese Han population were firstly identified. Although no significant correlation with asthma was revealed, the SNP and haplotype information is useful for other disease association studies in the future.
ObjectiveTo construct a luciferase reporter fusion containing the human connective tissue growth factor (CTGF) gene promoter.MethodsThe promoter region of the human CTGF gene (-835/+214) was amplified by polymerase chain reaction (PCR) using specially-designed primers, and subsequently cloned into the pGL3.0-Basic vector. Following screening and verification by single colony PCR, double digestion, and sequencing, the resulting pGL3.0-Basic-CTGF was used to transfect the human embryonic kidney cells 293T, human bronchial epithelial cells HBE and human lung epithelial cells A549, and its function in each cell line was determined by luciferase assay.ResultsSequence alignment showed 99.5% identity, suggesting successful construction of the pGL3.0-Basic-CTGF reporter fusion. Promoter activities were detected 48 hours after transfection of pGL3.0-Basic-CTGF into the 293T, HBE, and A549 cells, and the promoter activities were 2.416, 0.027, and 0.121, respectively (P<0.01). Moreover, the luciferase activity in the A549 cells was statistically higher than that in the HBE cells (P<0.01).ConclusionsThe human pGL3.0-Basic-CTGF luciferase reporter fusion has been successfully constructed. The construct exhibits promoter activity in the bronchial epithelial cells HBE and the lung epithelial cells A549, and can therefore serve as a useful tool for future research in transcriptional regulation.
ObjectiveTo explore the effect of five copies hypoxia-responsive element (5HRE) and carcinoembryonic antigen promoter (CEAp) element, and to explore the inhibition effect of lentiviral vectors targeted Ras association domain family 1 isoform A (RASSF1A) gene on SGC7901 human gastric cancer cells. Methods①Expressions of carcinoembryonic antigen (CEA) mRNA and its protein, and RASSF1A protein in SGC7901, MKN28, and MCF-10A cells were detect by real time-PCR (qRT-PCR), immunocytochemistry, and Western blot, to confirm the experimental and negative control cells.②The recombinant vectors of pGL4.20-5HRE-CEAp-Luc were constructed through molecular cloning technique to transfected SGC7901, MKN28, and MCF-10A cells. Each kind of cell was divided into 2 groups:one of them didn't add CoCl2 (normoxia group), and another group added CoCl2 (hypoxia group). Comparison of the fold of activation was performed.③SGC7901 cells were infected by lentiviral vectors of pLV-5HRE-CEAp-RASSF1A (infection group) and negative virus (negative control group), SGC7901 cells without any treatment as blank control group. Then SGC7901 cells of 3 groups were divided into 2 groups:one of them didn't add CoCl2 (normoxia group), and another group added CoCl2 (hypoxia group). The expression of RASSF1A protein was tested by Western blot, and the growth inhibition rate was confirmed by cell counting kit-8 (CCK-8) assay. Comparisons of expression of RASSF1A protein and growth inhibition rate of each group were performed. Results①Results of qRT-PCR, immunocytochemistry and Western blot showed that, SGC7901 cells showed higher expression of CEA mRNA and positive expression of RASSF1A protein than corresponding index of MKN28 cells and MCF-10A cells (P < 0.05), which were assigned as experimental cells; but MKN28 cells showed lower expression of CEA mRNA and negative expression of RASSF1A protein, which were assigned as negative control cells.②In SGC7901 and MKN28 cells transfected recombinant vectors of pGL4.20-5HRECEAp-Luc, compared with normoxia group in the same kind of cell group, the folds of activation in hypoxia group were higher (P < 0.01), but there was no significant difference between the normoxia group and hypoxia group in MCF-10A cells (P > 0.05). In the condition of with or without CoCl2, compared with SGC7901 cells in the same condition, the folds of activation in MCF-10A and MKN28 cells were both lower (P < 0.05); compared with MKN28 cells, the fold of activation in MCF-10A cells was lower (P < 0.05).③Western blot results showed that, in the condition with and without CoCl2, expressions of RASSF1A protein decreased in SGC7901 cells of blank control group and negative control group; weak expressions of RASSF1A protein was observed in SGC7901 cells of infection group when in condition of without CoCl2, but increased when adding CoCl2. But RASSF1A protein didn't expressed in MKN28 cells of blank control group, negative control group, and infection group, whether adding CoCl2 or not. CCK-8 assay result showed that, in SGC7901 cells, the growth inhibition rate of infection group which added CoCl2 was higher than those of other 5 groups (P < 0.05); in MKN28 cells, the growth inhibition rates of infection group and negative group were all higher than those of blank control group, whether adding CoCl2 or not (P < 0.05), but there was no significant difference among the infection group and negative group, whether adding CoCl2 or not (P > 0.05). ConclusionsA new hypoxia inducible and cea-positive tumor-targeting transcriptional regulatory element of 5HRE-CEAp is established successfully, and lentivirus vector of pLV-5HRE-CEAp-RASSF1A can significant inhibit the growth of SGC7901 cells under hypoxia condition.
目的 肿瘤坏死因子相关凋亡诱导配体（TRAIL）能够诱导乙型肝炎病毒（HBV）感染细胞发生凋亡，但抑制病毒复制的具体机制不清楚，研究通过非凋亡浓度TRAIL对4种HBV启动子调控作用的研究，探讨HBV复制的可能调控机制。 方法 采用噻唑蓝法和末端脱氧核苷酸转移酶介导的dUTP缺口末端标记荧光法，检测不同浓度TRAIL作用后人肝癌细胞株HepG2的存活率。使用HBV的4种启动子重组质粒，4种启动子分别控制乙肝表面抗原、X抗原、核心抗原、PS1抗原基因的转录与表达。将受HBV上述4种启动子调控的荧光素酶报道基因表达质粒（SpLUC、XpLUC、CpLUC、PS1pLUC）转染HepG2细胞，6 h后按300 、30 、3 ng/mL浓度梯度加入可溶性TRAIL，采用双荧光报道基因分析系统检测细胞化学发光值，计算相对荧光素酶活性。 结果 300 ng/mL是可溶性TRAIL诱导HepG2细胞凋亡的浓度阈值。采用远低于凋亡阈值浓度（30 ng/mL）的TRAIL可明显上调对HBV的 Sp启动子活性（P＜0.001），另3种质粒的相对荧光素酶活性在加入TRAIL后改变不大。 结论 TRAIL仅对HBV的 Sp启动子活性具有上调作用，其生物学意义值得进一步研究。
ObjectiveTo lay a theoretical foundation for the research of regulation of Hyperpolarization activated cyclic nucleotide gated channel 1 (HCN1) gene expression and its involvement in the pathogenesis of Mesio-temporal lobe epilepsy (MTLE) and other related diseases, the bioinformatics methods were used to analyze sequence characteristic, transcription factors and their binding sites in the promoter region of human HCN1 gene, and the physicochemical properties, signal peptides, hydrophobicity, transmembrane regions, protein structure, interacting proteins and functions of HCN1 proteins.MethodBiological software and website, such as Protparam, Protscale, MHMM, SignalP 5.0, NetPhos 3.1, Swiss-Model, Promoter 2.0, AliBaba2.1 and EMBOSS were used to analyze and predict physicochemical properties, structural functions, localized expression, phylogenetic relationships and protein interactions with human HCN1 protein, and promoter, CpG island and transcription factor characteristics of HCN1 gene.ResultsThe evolutionary analysis of HCN1 protein showed that the genetic distance between human and Pongo abelii was the smallest, indicating the closest genetic relationship between human and Pongo abelii. Human HCN1 protein was an unstable hydrophilic protein located on the plasma membrane, which contained two transmembrane structure. However, the predicted results showed that there was no signal peptide and nuclear localization sequence in this protein. The secondary structure of HCN1 protein was mostly random coil and alpha helix, and it contained multiple potential phosphorylation sites. The ontology analysis results of HCN1 protein were showed as follows. The cellular component of HCN1 protein was located in the plasma membrane (GO:0005886); the molecular functionof HCN1 protein were cyclic adenosine monophosphate binding (GO:0030552) and voltage-gated ion channel activity (GO:0005244); the biological process of this protein were reacting to cAMP (GO:0071320) and transmembrane transport of potassium (GO:0071805). The analysis results of String database showed that the proteins that had close interaction with human HCN1 protein mainly included the ten proteins (HCN2, HCN4, PEX5L, MARCH7, KCTD3, GNAT3, SHKBP1, KCNQ2, FLNA and NEDD4L). These proteins were mainly involved in regulation of ion transport and transmembrane transport of potassium (GO:0071805). The HCN1 gene was located at 5p12 and contained 8 exons and 7 introns.There were at least three promoter regions in the nucleotide sequence of 2 000 bp from the upstream of the HCN1 gene to the 5 'flanks, and contained a 158 bp CpG island in the promoter region and one TATA boxes and one CAAT boxes in the 5' regulation region ofHCN1 gene; niceteen transcription factors, including NF-κB, NF-1, AP-1, TBP, IRF-1, c-Ets-1, Elf-1, HNF-3, HNF-1, YY1, GATA-1, RXR-α, GR, AP-2αA, ENKTF-1, C/EBPβ, C/EBPα, c-Fos and c-Jun, binding in the promoter region of the HCN1 gene were predicted by both softwares (AliBaba2.1 and PROMO2).ConclusionThe analysis results provide important information for further studies on the role of HCN1. Bioinformatics analysis of the promoter region can improve the research efficiency of gene promoters, and provide theoretical basis for subsequent experiments to construct expression vectors of HCN1 gene promoters and identify their functions.