50 research outputs found
The rate of the founder Jewish mutations in BRCA1 and BRCA2 in prostate cancer patients in Israel
Inherited predisposition occurs in 5–10% of all prostate cancer (CaP) patients, but the genes involved in conferring genetic susceptibility remain largely unknown. Several lines of evidence indicate that germline mutations in BRCA1 and BRCA2 might be associated with an increased risk for CaP. Three mutations in these two genes (185delAG and 5382InsC (BRCA1) and 6174delT (BRCA2) occur in about 2.5% of the general Ashkenazi population, and the 185delAG BRCA1 mutation, in up to 1% of non-Ashkenazi Jews. In order to assess the contribution of these germline mutations to prostate cancer in Jewish Israeli patients, we tested 174 unselected prostate cancer patients (95 of Ashkenazi origin) for these mutations by PCR amplification and modified restriction enzyme digests. Patient’s age range was 45–81 years (median 66), and in 24 (14.4%) the disease was diagnosed prior to 55 years of age. Nineteen (11%) and 12 (6.9%) patients had a first or second degree relative with CaP or breast cancer, respectively. Overall, five mutation carriers were detected: 2/152 (1.3%) 185delAG, 2/104 (2%) 5382InsC, and 1/158 (0.6%) 6174delT. In all carriers, the disease was diagnosed after the age of 55, and only one of them had a family history of breast and CaP. In addition, no allelic losses at the BRCA1 locus were demonstrated in 17 patients with a family history of CaP, using seven microsatellite markers. We conclude that the rate of the predominant Jewish BRCA1 and BRCA2 mutations in CaP patients does not significantly differ from that of the general population, and that mutational inactivation of the BRCA1 is rare in familial CaP. Thus, germline BRCA1 and BRCA2 mutations probably contribute little to CaP occurrence, to inherited predisposition, and to early onset disease in Jewish individuals. © 2000 Cancer Research Campaig
Prostate cancer in male BRCA1 and BRCA2 mutation carriers has a more aggressive phenotype
There is a high and rising prevalence of prostate cancer (PRCA) within the male population of the United Kingdom. Although the relative risk of PRCA is higher in male BRCA2 and BRCA1 mutation carriers, the histological characteristics of this malignancy in these groups have not been clearly defined. We present the histopathological findings in the first UK series of BRCA1 and BRCA2 mutation carriers with PRCA. The archived histopathological tissue sections of 20 BRCA1/2 mutation carriers with PRCA were collected from histopathology laboratories in England, Ireland and Scotland. The cases were matched to a control group by age, stage and serum PSA level of PRCA cases diagnosed in the general population. Following histopathological evaluation and re-grading according to current conventional criteria, Gleason scores of PRCA developed by BRCA1/2 mutation carriers were identified to be significantly higher (Gleason scores 8, 9 or 10, P=0.012) than those in the control group. Since BRCA1/2 mutation carrier status is associated with more aggressive disease, it is a prognostic factor for PRCA outcome. Targeting screening to this population may detect disease at an earlier clinical stage which may therefore be beneficial
Atiprimod blocks STAT3 phosphorylation and induces apoptosis in multiple myeloma cells
Multiple myeloma (MM) accounts for 1 % of all cancer deaths. Although treated aggressively, almost all myelomas eventually recur and become resistant to treatment. Atiprimod (2-(3-Diethylaminopropyl)-8,8-dipropyl-2-azaspiro[4,5] decane dimaleate) has exerted anti-inflammatory activities and inhibited oeteoclast-induced bone resorption in animal models and been well tolerated in patients with rheumatoid arthritis in phase I clinical trials. Therefore, we investigated its activity in MM cells and its mechanism of action. We found that Atiprimod inhibited proliferation of the myeloma cell lines U266-B1, OCI-MY5, MM-1, and MM-1R in a time- and dose-dependent manner. Atiprimod blocked U266-B1 myeloma cells in the G0/G1 phase, preventing cell cycle progression. Furthermore, Atiprimod inhibited signal transducer and activator of transcription (STAT) 3 activation, blocking the signalling pathway of interleukin-6, which contributes to myeloma cell proliferation and survival, and downregulated the antiapoptotic proteins Bcl-2, Bcl-XL, and Mcl-1. Incubation of U266-B1 myeloma cells with Atiprimod induced apoptosis through the activation of caspase 3 and subsequent cleavage of the DNA repair enzyme poly(adenosine diphosphate-ribose) polymerase. Finally, Atiprimod suppressed myeloma colony-forming cell proliferation in fresh marrow cells from five patients with newly diagnosed MM in a dose-dependent fashion. These data suggest that Atiprimod has a role in future therapies for MM
Stat3 Activates the Receptor Tyrosine Kinase Like Orphan Receptor-1 Gene in Chronic Lymphocytic Leukemia Cells
BACKGROUND: The receptor tyrosine kinase like orphan receptor (ROR)-1 gene is overexpressed in chronic lymphocytic leukemia (CLL). Because Stat3 is constitutively activated in CLL and sequence analysis revealed that the ROR1 promoter harbors gamma-interferon activation sequence-like elements typically activated by Stat3, we hypothesized that Stat3 activates ROR1. METHODOLOGY/PRINCIPAL FINDINGS: Because IL-6 induced Stat3 phosphorylation and upregulated Ror1 protein levels in MM1 cells, we used these cells as a model. We transfected MM1 cells with truncated ROR1 promoter luciferase reporter constructs and found that IL-6 induced luciferase activity of ROR1-195 and upstream constructs. Co-transfection with Stat3 siRNA reduced the IL-6-induced luciferase activity, suggesting that IL-6 induced luciferase activity by activating Stat3. EMSA and the ChIP assay confirmed that Stat3 binds ROR1, and EMSA studies identified two Stat3 binding sites. In CLL cells, EMSA and ChIP studies determined that phosphorylated Stat3 bound to the ROR1 promoter at those two ROR1 promoter sites, and ChIP analysis showed that Stat3 co-immunoprecipitated DNA of STAT3, ROR1, and several Stat3-regulated genes. Finally, like STAT3-siRNA in MM1 cells, STAT3-shRNA downregulated STAT3, ROR1, and STAT3-regulated genes and Stat3 and Ror1 protein levels in CLL cells. CONCLUSION/SIGNIFICANCE: Our data suggest that constitutively activated Stat3 binds to the ROR1 promoter and activates ROR1 in CLL cells
Nanostructural Mechanism of Modifying Adaptation of Proteoglycan Systems of Biological Tissues and Mucus
Lymphadenectomy in bladder cancer: What should be the extent?
The extent of Lymh node dissection (LND) during radical cystectomy is a subject of increasing importance with several studies suggesting that an extended LND may improve staging accuracy and outcome. Significant numbers of patients have lymph node metastasis above the boundaries of standard LND. Extended LND yields higher number of lymph nodes which may result in better staging. Various retrospective studies have reported better oncological outcomes with extended LND compared to limited LND. No difference in the mortality and the incidence of lymphocele formation has been found between ‘standard’ and ‘extended’ LND. Till we have a well-designed randomized controlled trial to address these issues for level 1 evidence, it is not justified to deny our patients the advantages of ‘extended’ lymphadenectomy based on the current level of evidence
DICSI station at KCSR and NT: Determination of optimal requirements to the formation of an SR beam using cylindrical x-ray optical zoom lenses
De novo design of fibrils made of short alpha-helical coiled coil peptides
BACKGROUND: The alpha-helical coiled coil structures formed by 25-50 residues long peptides are recognized as one of Nature's favorite ways of creating an oligomerization motif. Known de novo designed and natural coiled coils use the lateral dimension for oligomerization but not the axial one. Previous attempts to design alpha-helical peptides with a potential for axial growth led to fibrous aggregates which have an unexpectedly big and irregular thickness. These facts encouraged us to design a coiled coil peptide which self-assembles into soluble oligomers with a fixed lateral dimension and whose alpha-helices associate in a staggered manner and trigger axial growth of the coiled coil. Designing the coiled coil with a large number of subunits, we also pursue the practical goal of obtaining a valuable scaffold for the construction of multivalent fusion proteins. RESULTS: The designed 34-residue peptide self-assembles into long fibrils at slightly acid pH and into spherical aggregates at neutral pH. The fibrillogenesis is completely reversible upon pH change. The fibrils were characterized using circular dichroism spectroscopy, sedimentation diffusion, electron microscopy, differential scanning calorimetry and X-ray fiber diffraction. The peptide was deliberately engineered to adopt the structure of a five-stranded coiled coil rope with adjacent alpha-helices, staggered along the fibril axis. As shown experimentally, the most likely structure matches the predicted five-stranded arrangement. CONCLUSIONS: The fact that the peptide assembles in an expected fibril arrangement demonstrates the credibility of our conception of design. The discovery of a short peptide with fibril-forming ability and stimulus-sensitive behavior opens new opportunities for a number of applications