The role of asymmetric dimethyl arginine and oxidant/antioxidant system in preeclampsia.

Preeclampsia is a syndrome characterized by hypertension and proteinuria. The aim of this study is to find the relationship between preeclampsia, asymmetric dimethyl arginine (ADMA), and the oxidant/antioxidant system. Twenty-one preeclamptic and 28 normal pregnant women were included in this study. In cord bloods, ADMA and oxidant/antioxidant parameters were measured. Asymmetric dimethyl arginine levels were significantly increased in preeclamptic pregnancies compared to the control group (p = 0.006). The activities of antioxidant enzymes and malondialdehyde levels were increased in the preeclamptic group compared to the control group (p < 0.001, p = 0.022, p < 0.001, p < 0.001, respectively). Development of endothelial dysfunction and oxidative stress may play a role in developing preeclampsia.

Cord blood and maternal serum neopterin concentrations in patients with pre-eclampsia.

BACKGROUND: Pre-eclampsia is a syndrome characterized by hypertension and proteinuria. The aim of this study was to investigate neopterin concentrations in cord blood and maternal serum in patients with pre-eclampsia and a control group. METHODS: Cord blood and maternal serum neopterin were measured in 21 patients with pre-eclampsia and in 27 control subjects. Neopterin concentrations were measured by high performance liquid chromatography. RESULTS: Cord blood neopterin concentrations were significantly increased in patients with pre-eclampsia compared to controls (54.3+/-16.8 vs. 43.4+/-8.5 nmol/L, p=0.011, respectively). Maternal serum neopterin (257.3+/-36.8 vs. 150.9+/-33.8 nmol/L, p<0.001) was also higher in patients with pre-eclampsia. CONCLUSIONS: Cord blood and maternal serum neopterin concentrations are higher in patients with pre-eclampsia. Maternal serum neopterin concentrations used may be used as a marker for the early diagnosis of pre-eclampsia.

In vivo and in vitro effects of a HIF-1alpha inhibitor, RX-0047.

HIF-1alpha plays a major role in activating gene transcription and is important for maintaining homeostasis under hypoxic conditions. Since tumors are often in a hypoxic state, HIF-1alpha is a potential target for the development of novel cancer therapeutics. This study was performed to determine the antitumoral efficacy of an antisense HIF-1alpha inhibitor, RX-0047 on different human cancer cell lines (MDA-MB 231, HME50-T, PC-3, Panc-1 and A549) in vitro. A549 lung cancer and PC-3 prostate cancer cells containing a luciferase gene reporter were used for in vivo xenograft animal models. Progressive tumor development was quantified using live animal BLI (bioluminescence imaging) in addition to ex vivo imaging and histology. All cell lines tested were sensitive to inhibition of cell growth with 10 nM and higher ranges of RX-0047, additionally RX-0047 sensitizes cells to ionizing radiation treatments. Finally, RX-0047 (30 mg/kg) inhibited the formation of human lung metastasis in xenograft mouse models and reduced tumor size in flank models.

Construction of recB-recD genetic fusion and functional analysis of RecBDC fusion enzyme in Escherichia coli.

BACKGROUND: recD, located between recB and argA, encodes the smallest polypeptide (60 kDa) of the heterotrimeric enzyme RecBCD in Escherichia coli. RecD is a 5'-3' helicase and is required for the nuclease activity of RecBCD and for tight binding to dsDNA ends. Here, we have tested the hypothesis that RecD regulates the structure and activities of RecBCD, including RecA loading. RESULTS: To characterize its regulatory functions, recD was genetically fused to recB through deletion and substitution mutations. The recB-recD fusion led to a decreased amount of the heterotrimer. Both fusion mutants proved to be recombination proficient, viable and resistant to DNA damaging agents, and to have DNA unwinding, ATP-dependent dsDNA exonuclease and Chi genetic activities. CONCLUSION: Our findings suggest that the recB-recD fusion may form a RecBD fusion protein and therefore affect RecD assembly, but this does not change the three-dimensional structure of the heterotrimer.

In vivo inhibition of lung cancer by GRN163L: a novel human telomerase inhibitor.

Differential regulation of telomerase activity in normal and tumor cells provides a rationale for the design of new classes of telomerase inhibitors. The telomerase enzyme complex presents multiple potential sites for the development of inhibitors. GRN163L, a telomerase enzyme antagonist, is a lipid-modified 13-mer oligonucleotide N3' --> P5'-thio-phosphoramidate, complementary to the template region of telomerase RNA (hTR). We evaluated both the in vitro and in vivo effects of GRN163L using A549-luciferase (A549-Luc) human lung cancer cells expressing a luciferase reporter. GRN163L (1 micromol/L) effectively inhibits telomerase activity of A549-Luc cells, resulting in progressive telomere shortening. GRN163L treatment also reduces colony formation in soft agar assays. Surprisingly, after only 1 week of treatment with GRN163L, A549-Luc cells were unable to form robust colonies in the clonal efficiency assay, whereas the mismatch control compound had no effect. Finally, we show that in vivo treatment with GRN163L is effective in preventing lung metastases in xenograft animal models. These in vitro and in vivo data support the development of GRN163L as a therapeutic for the treatment of cancer.

Detection of telomerase activity in bronchial lavage as an adjunct to cytological diagnosis in lung cancer.

OBJECTIVE: Definitive diagnosis of lung cancer with conventional methods may sometimes be difficult in clinical practice. Telomerase is a ribonucleoprotein DNA polymerase that maintains the telomeric region of chromosomes during successive rounds of cell division. Telomerase activity in body cavity fluids has been advocated to be a potential diagnostic marker for malignancy. We investigated the diagnostic value of telomerase activity in bronchial lavage samples of patients undergoing diagnosis of lung cancer. METHODS: A total of 29 bronchial lavage samples were collected from patients in whom the diagnosis was confirmed with cytological and/or histological examinations. Patients were classified as lung cancer patients (Group 1, n = 22) and patients with benign disease (Group 2, n = 7). Telomerase activity was determined with polymerase chain reaction-based TRAP (The telomeric repeat amplification protocol) assay. RESULTS: Cytological examination was diagnostic in 12 (54.5%) of 22 patients in Group 1, and in all seven patients of Group 2 (P = 0.063). Telomerase activity was positive in 16 (72.7%) of Group 1 patients, while it was positive in only 1 (14.3%) sample of a lung abscess in Group 2 (P = 0.011). The sensitivity rate of cytological examination when combined with telomerase activity (81.8%) was significantly greater than that of cytological examination alone (54.5%) (P = 0.031). The sensitivity and specificity of telomerase activity were 72.7 and 85.7%, respectively. Telomerase activity had a positive predictive value as 0.94 and negative predictive value as 0.50. Diagnostic accuracy of telomerase activity was 75.8%. CONCLUSION: Telomerase activity in bronchial lavage is a highly sensitive diagnostic biomarker for malignancy and a potential complementary diagnostic technique to cytological examination in the diagnosis of lung cancer.

Telomerase activity in diagnosis of bladder cancer.

OBJECTIVE: Telomerase is an enzyme that can reconstitute the ends of chromosomes after cell division and thus circumvent the damage that occurs in normal adult somatic cells during successive mitotic cycles. Immortal cells have short but stable chromosomes and increased telomerase activity. Transitional cell carcinoma (TCC) has only a few useful markers of diagnostic or prognostic importance. The objectives of this study were to determine whether there was a correlation between telomerase activities and the grade or stage of TCC and whether the activity of the enzyme could serve as a biochemical marker of this tumor. MATERIAL AND METHODS: Telomerase activity was determined by examining, using a polymerase chain reaction-based assay designed using the telomeric repeat amplification protocol (TRAP), urine cell pellets obtained from 42 bladder cancer patients, 18 patients with primary hematuria, 19 patients with benign urologic disease, 14 patients with urologic malignancies other than TCC and 20 healthy volunteers. RESULTS: Telomerase activity was found in 24/31 patients with bladder tumors (77.4% sensitivity) and in 5/77 patients without tumors (93.5% specificity). No correlation was found between telomerase activity and the grade or stage of the tumor. Although none of the urine cell pellets obtained from the 20 healthy volunteers demonstrated telomerase activity, positive telomerase activity was found in two subjects in the benign urologic disease group and in three subjects in the other urologic malignancy group. It was demonstrated that gross hematuria was the cause of false-negative results in six of the nine patients (66.7%). but washing the pellets four times and diluting them before the TRAP assay solved this problem. CONCLUSION: These results indicate that telomerase activity may be a promising marker for TCC but the technical aspects of the technique must be improved before it is used in routine clinical practice as a standard method. False-negative results obtained using gross hematuric urine should be carefully reevaluated and cell pellets should be washed again and diluted before analysis.

Lipid peroxidation and erythrocyte antioxidant enzymes in patients with Behçet's disease.

In spite of unknown etiology, it is now accepted that reactive oxygen species (ROS) produced by neutrophils may be related to the pathogenesis of Behçet's Disease (BD). The objective was to investigate whether increased production of ROS may affect erythrocyte oxidant/antioxidant system in patients with BD. The levels of malondialdehyde (MDA), one of the end products of lipid peroxidation, in plasma and erythrocyte, and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), antioxidant enzymes, in erythrocyte, also C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were measured in 22 patients in active stage of the disease and also in 30 healthy controls. Increased CRP, ESR, and MDA levels in plasma and erythrocyte and increased SOD but decreased GSH-Px activities in erythrocytes were observed in the patients, when compared to the controls. In addition, significantly positive correlations between plasma and erythrocyte MDA levels, and erythrocyte MDA-CRP, MDA-ESR, MDA-SOD, SOD-ESR and SOD-CRP levels, but negative correlation between plasma MDA and erythrocyte GSH-Px, were found in BD patients. It may be suggested that increased production of ROS in BD, as reflected by higher plasma and erythrocyte MDA levels, may impair erythrocyte membrane integrity and also may lead to the alterations in the erythrocyte antioxidant defense system, as reflected by higher SOD and lower GSH-Px activities in erythrocytes.