Relationship between the expression of human telomerase reverse transcriptase gene and cell cycle regulators in gastric cancer and its significance

AIM: To investigate the expression of human telomerase reverse transcriptase gene (hTRT) in gastric cancer (GC)and its relevance with cell cycle regulators including P16INK4,cyclin and P53.METHODS: In situ hybridization (ISH) for hTRT mRNA was performed in 53 cases of gastric cancer and adjacent cancerous tissues. Immunohistochemical staining (S-Pmethod) for hTRT protein, P16INK4, cyclinD1 and P53 was performed in 53 cases of GC and adjacent cancerous tissues.RESULTS: Of 53 cases of GC, the expression of hTRT mRNA and hTRT protein was significantly higher than the expression of hTRT mRNA and hTRT protein in adjacent canerous tissues (P＜0.01), the positive rates of hTRTmRNA and hTRT protein were 79.2 % and 88.6 %. There was a stastical difference of the expression of hTRT protein among well differentiated adenocarcinoma, poorly differentiated adenocarcinoma and mucoid carcinoma. And there was a highly significant positive correlation between the expression of hTRT mRNA and hTRT protein (r=0.625, P＜0.01). However, the expression of hTRT mRNA and its protein in GC were not related with other clinicopathological parameters including gender, age, location and size of neoplasm, invasion depth, lymph node metastasis and clinical stage. There was a significant positive correlation between the expression of hTRT mRNA and cyclinD1 protein (r=0.350, P＜0.01). There was a significant positive correlation between the expression of cyclinD1 protein and hTRT protein (r=0.549, P＜0.01), so was between P53 and hTRT protein (r=0.319, P＜0.05).CONCLUSION: The expression of hTRT gene is correlated significantly to the specific defects of cell cycle on G1/S check point; telomerase activity may depend on cell cycle in gastric cancer and it is available to clarify the molecular mechanism of telomerase activity regulation. The expression of hTRT mRNA and hTRT protein in GC is significantly different from the expression of hTRT mRNA and hTRT protein in adjacent cancerous tissue which indicates that these targets are correlated closely to the occurrence of GC and can provide important morphologic index for diagnosis of GC.

Clinical phenotype and prevalence of hereditary nonpolyposis colorectal cancer syndrome in Chinese population

AIM: To descr ibe systematically the clinical characteristics and phenotype of HNPCC families and the prevalence of HNPCC in the general population of CRC patients in China.METHODS: HNPCC kindreds and CRC patients were from two sources. One was that we consecutively investigated kindreds and patients by ourselves. And the other was the published Chinese and foreign literature related to Chinese HNPCC syndrome. There were 142 HNPCC families fulfilling AC Ⅰ and/or AC Ⅱ including 57 families with detailed data, and 3874 general primary CRC patients in all. All statistical tests were two-sided.RESULTS: In AC Ⅰ families, the number of Lynch syndrome Ⅰ and Ⅱ families were 25 (47.2%) and 28 (52.8%)respectively. There were 215 patients (82.4%) with CRC,67 patients (25.7%) with extracolonic cancer and 50patients (19.2%) with multiple primary cancers. In all CRC patients, multiple primary CRC were in 41 patients (19.1%),and the first-CRC was right-sided colorectal cancer in 143 patients (66.5%) and rectal cancer in 44 patients (20.5%). 8.8% and 19.2% of the first cancer were CRC and extracolonic cancers. Among those patients whose first cancer was CRC, 66.8% and 19.9% were right-sided colorectal cancer and rectal cancer, respectively. The similar results were found in AC Ⅱ families. Normal distribution was only found in the distribution of the age of diagnosis of the first cancer in both AC Ⅰ families (coefficient of skewness: u = 0.81, 0.20＜0.40＜P＜0.50;coefficient of kurtosis: u = 1.13, 0.20＜P＜0.40, α = 0.20)and AC Ⅱ families (coefficient of skewness: u = 0.63, P＞0.5＞0.20; coefficient of kurtosis: u = 0.84, 0.20＜0.40＜P＜0.50,α = 0.20), but not found in the distribution of the age of diagnosis of the first CRC. When patients with HNPCC-associated cancer suffered from the first malignant tumor in HNPCC families diagnosed by AC Ⅰ and AC Ⅱ, the mean age and median age were 45.1±12.7 years and 44.0 years,45.2±12.7 years and 44.5 years, respectively. The median age of diagnosis of the first tumor of the patients in the later generation was younger than that in the previous generation. Many extracolonic cancers were found to be associated with HNPCC syndrome. Gastric cancer was the most frequent extracolonic cancer followed by endometrial cancer and hepatocarcinoma. In general population of CRC patients, the prevalence of HNPCC diagnosed by AC Ⅰ and AC Ⅱ were 1.3% and 2.2%, respectively.CONCLUSION: The clinical phenotype and prevalence of Chinese HNPCC syndrome are similar to those of Europeans and Americans. Gastric cancer is the most common extracolonic malignant tumor. The age of diagnosis of the first malignant tumor tends to be increasingly younger in patients with HNPCC-related tumors.

Detection of K-ras point mutation and telomerase activity during endoscopic retrograde cholangiopancreatography in diagnosis of pancreatic cancer

AIM: To study the value of monitoring K-ras point mutation at codon 12 and telomerase activity in exfoliated cells obtained from pancreatic duct brushings during endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of pancreatic cancer.METHODS: Exfoliated cells obtained from pancreatic duct brushings during ERCP were examined in 27 patients: 23 with pancreatic cancers, 4 with chronic pancreatitis. K-ras point mutation was detected with the polymerase chain reaction and restriction fragment-length polymorphism(PCR-RFLP). Telomerase activity was detected by PCR and telomeric repeat amplification protocol assay (PCR-TRAP-ELISA).RESULTS: The telomerase activities in 27 patients were measured in 21 exfoliated cell samples obtained from pancreatic duct brushings. D450 value of telomerase activities in pancreatic cancer and chronic pancreatitis were 0.446+0.27 and 0.041+0.0111, respectively. Seventy-seven point eight percent (14/18) of patients with pancreatic cancer and none of the patients with chronic pancreatitis showed telomerase activity in cells collected from pancreatic duct brushings when cutoff value of telomerase activity was set at 2.0. The K-ras gene mutation rate (72.2%) in pancreatic cancer was higher than that in chronic pancreatitis (33.3%) (P<0.05). In considering of both telomerase activities and K-ras point mutation, the total positive rate was 83.3% (15/18), and the specificity was 100%.CONCLUSION: Changes of telomerase activities and K-ras point mutation at codon 12 may be an early event of malignant progression in pancreatic cancer. Detection of telomerase activity and K-ras point mutation at codon 12 may be complementary to each other, and is useful in diagnosis of pancreatic cancer.

Cyclic Voltammetry Determination of Epinephrine with a Nano-gold Modified Glassy Carbon Electrode in the Presence of High Concentration Ascorbic Acid

Nano-gold (NG) modified glassy carbon electrodes (GCEs) were used for determination of epinephrine (EP) in the presence of high concentration ascorbic acid (AA) by cyclic voltammetry (CV). This modified electrode can not only catalytically oxidize EP and AA, but also separate the catalytic peak potentials of EP and AA by about 183.5 mV. In pH = 7.0 ogisogate byffer solution, the linear range of epinephrine was 5 106 ~ 1 ?10-4 mol/L.

The Study of Electrochemical Behavior of Dopamine at Nano-gold Modified Carbon Fiber Electrode

The electrochemical behaviors (cyclic voltammetry, CV and different pulse voltammetry, DPV) of dopamine (DA) were studied in this paper. The result indicated that the oxidation of dopamine was controlled by diffusion and adsorption simultaneously at nano-gold (NG) modified carbon fiber electrode (CFE). This modified electrode can separate the peak potentials of dopamine and ascorbic acid (AA). The peak current of DA in DPV curve was found to be linearly proportional to the concentration of DA at range of 2.0?0-6～1.5?0-5mol/L and 1.0?0-5～5.0?0-4mol/L, respectively.

Relationships of tumor inflammatory infiltration and necrosis with microsatellite instability in colorectal cancers

AIM: The relationships between microsatellite instability(MSI) and survival in colorectal cancer patients are not consistent. The favorable survival of patient with MSI has been suggested to be related to pronounced inflammatory infiltration; however, the reason for non-association of MSI with survival is unclear. Our aims were to investigate the associations of inflammatory infiltration and tumor necrosis (TN) with microsatellite status and clinicopathological factors in colorectal cancer patients in whom MSI was not related to survival.METHODS: Three hundred and one colorectal adenocarcinomas were evaluated for inflammatory infiltration and 300 for TN under light microscope.RESULTS: Low infiltration at invasive margin (χ^2 = 3.94,P = 0.047) and in whole tumor stroma (χ^2 = 3.89, P = 0.049)was associated with MSI, but TN was not (χ^2=0.10,P = 0.75). Low infiltration was related to advanced stage(χ^2= 8.67, P = 0.03), poorer differentiation (χ^2= 8.84,P = 0.03), DNA non-diploid (χ^2= 10.04, P = 0.002),higher S-phase fraction (χ^2 = 11.30, P = 0.004), positive p53 expression (χ^2= 7.94, P = 0.01), and worse survival(P = 0.03 for both univariate and multivariate analyses).Abundant TN was related to advanced stage (χ^2 = 17.74,P = 0.001) and worse survival (P = 0.02 for univariate,and P = 0.05 for multivariate analysis).CONCLUSION: The result that high inflammatory infiltration was not related to MSI might help explain the non-association of MSI with survival in colorectal cancer patients.

The Figure and Dynamical Parameters of Io Inferred from Internal Structure Models

The recent Galileo spacecraft explored Jupiter and its satellite system and provided us with new geodetic data. In order to discuss the dynamical parameters and secular tidal effect of Io, the theory of synchronous satellite is described in detail. Using the new geodetic data of Io, two sets of Io's internal structure models are constructed based on the asthenosphere assumption. The liberation parameters α,β,γ and dynamical flattening H are calculated for the models of Io. A comparison of Io with the Moon indicates that they are quite different in many characteristics in spite of the fact that they are approximately equal in mass and size and that they both orbit synchronously.

Expression of TIMP-3 Gene by Construction of a Eukaryotic Cell Expression Vector and Its Role in Reduction of Metastasis in a Human Breast Cancer Cell Line

The present study is aimed at studying the gene for TIMP-3,a mammalian tissue inhibitor,by constructing a recombinant eukaryotic cell vector for gene therapy in human breast cancer.We obtained the TIMP-3 gene from the human placent by RT-PCR.TIMP-3 gene was subcloned into pcDNA3.1 vetor from pMD18T vector by means of gene cloning to construct pcDNA3.1 recombinant vector.Human breast cancer cell line MDA-MB-453 was transfected with pcDNA3.1-TIMP3 recombinant vector using lipofectamine reagent.Then the expression of TIMP-3 and the effect on the metastasis of MDA-MB-453 were examined.The correct construction of pcDNA-TIMP3 was identified by means of restriction enzyme analysis,PCR amplication and nucleotide sequencing.Western blotting showed that the transfected cells were able to express TIMP-3, indicating that our construction of the pcDNA-TIMP3 eukaryotic expression vector was constructed successfully.Our experiments further indicated that the potential of metastasis was significantly reduced for the transfected cell line MDA-MB-453.Cellular & Molecular Immunology.2004;1(4):308-310.

Influence of Gd doping on the absolute quantum efficiency and lifetime of Eu_xGd_(1-x)(TTA)_3 phens

Absolute quantum yield （Ф） is one of the most important parameters to evaluate the potential of novel materials. Lanthanide complexes EuxGd1-x（TTA）3phens are synthesized with the ratio of Gd3＋ dopant concentration ranging from 10% to 90% to improve the absolute quantum yield. EuxGd1-x（TTA）3phens possess similar infrared and ultraviolet spectra, showing that they have similar molecular structures. The absolute emission quantum yields of EuxGd1-x（TTA）3phens are determined using a fluoromax-4 spectrofluorometer equipped with an integrating sphere. The fluorescence lifetimes of the EuxGd1-x（TTA）3phens are measured in the same experiment. It was found that both absolute quantum yields and fluorescence lifetimes of EuxGd1-x（TTA）3phens are of quasi-periodic variation with the change of the Gd3. dopant concentrations. The absolute quantum efficiency and fluorescence lifetime vary with respect to the Gd content in an opposite fashion, indicating that the rate of energy absorption by the EuxGd1-x（TTA）3phens and the conversion to light energy is critical for the absolute quantum efficiency. The radiative rate constant Kr and non-radiative rate constant Knr are calculated. The dependence of Kr and Knr on the Gd3＋ dopant concentrations is very similar to that of absolute quantum efficiency. The radiation rate constant Kr and absolute quantum efficiency have a linear relationship.

A Real-Time and Dynamic Biological Information Retrieval and Analysis System(BIRAS)

The aim of this study is to design a biological information retrieval and analysis system (BIRAS) based on the Internet. Using the specific network protocol, BIRAS system could send and receive information from the Entrez search and retrieval system maintained by National Center for Biotechnology Information (NCBI) in USA. The literatures, nucleotide sequence, protein sequences, and other resources according to the user-defined term could then be retrieved and sent to the user by pop up message or by E-mail informing automatically using BIRAS system. All the information retrieving and analyzing processes are done in real-time. As a robust system for intelligently and dynamically retrieving and analyzing on the user-defined information, it is believed that BIRAS would be extensively used to retrieve specific information from large amount of biological databases in now days. The program is available on request from the corresponding author.