Presymptomatic breast cancer in Egypt: role of BRCA1 and BRCA2 tumor suppressor genes mutations detection

<p>Abstract</p> <p>Background</p> <p>Breast cancer is one of the most common diseases affecting women. Inherited susceptibility genes, <it>BRCA1 </it>and <it>BRCA2</it>, are considered in breast, ovarian and other common cancers etiology. <it>BRCA1 </it>and <it>BRCA2 </it>genes have been identified that confer a high degree of breast cancer risk.</p> <p>Objective</p> <p>Our study was performed to identify germline mutations in some exons of <it>BRCA1 </it>and <it>BRCA2 </it>genes for the early detection of presymptomatic breast cancer in females.</p> <p>Methods</p> <p>This study was applied on Egyptian healthy females who first degree relatives to those, with or without a family history, infected with breast cancer. Sixty breast cancer patients, derived from 60 families, were selected for molecular genetic testing of <it>BRCA1 </it>and <it>BRCA2 </it>genes. The study also included 120 healthy first degree female relatives of the patients, either sisters and/or daughters, for early detection of presymptomatic breast cancer mutation carriers. Genomic DNA was extracted from peripheral blood lymphocytes of all the studied subjects. Universal primers were used to amplify four regions of the <it>BRCA1 </it>gene (exons 2,8,13 and 22) and one region (exon 9) of <it>BRCA2 </it>gene using specific PCR. The polymerase chain reaction was carried out. Single strand conformation polymorphism assay and heteroduplex analysis were used to screen for mutations in the studied exons. In addition, DNA sequencing of the normal and mutated exons were performed.</p> <p>Results</p> <p>Mutations in both <it>BRCA1 </it>and <it>BRCA2 </it>genes were detected in 86.7% of the families. Current study indicates that 60% of these families were attributable to <it>BRCA1 </it>mutations, while 26.7% of them were attributable to <it>BRCA2 </it>mutations. Results showed that four mutations were detected in the <it>BRCA1 </it>gene, while one mutation was detected in the <it>BRCA2 </it>gene. Asymptomatic relatives, 80(67%) out of total 120, were mutation carriers.</p> <p>Conclusions</p> <p><it>BRCA1 </it>and <it>BRCA2 </it>genes mutations are responsible for a significant proportion of breast cancer. <it>BRCA </it>mutations were found in individuals with and without family history.</p

Search for the standard model Higgs boson produced in association with a top-quark pair in pp collisions at the LHC

A search for the standard model Higgs boson produced in association with a top-quark pair is presented using data samples corresponding to an integrated luminosity of 5.0 fb(-1) (5.1 fb-1) collected in pp collisions at the center-of-mass energy of 7 TeV (8 TeV). Events are considered where the top-quark pair decays to either one lepton+jets (t (t) over bar -> l nu q (q) over bar 'b (b) over bar) or dileptons (t (t) over bar -> l(+)nu l-nu b (b) over bar), being an electron or a muon. The search is optimized for the decay mode H -> b (b) over bar. The largest background to the t (t) over barH signal is top-quark pair production with additional jets. Artificial neural networks are used to discriminate between signal and background events. Combining the results from the 7 TeV and 8 TeV samples, the observed (expected) limit on the cross section for Higgs boson production in association with top-quark pairs for a Higgs boson mass of 125 GeV is 5.8 (5.2) times the standard model expectation