127 Greek breast/ovarian cancer families were screened for germline BRCA1/2 mutations by dHPLC followed by direct sequencing. Our results indicated 16 and 5 breast/ovarian cancer families bearing deleterious mutations in the BRCA1 and BRCA2 genes, respectively. Two novel BRCA2 germline mutations (G4X and 3783del10) are reported here for the first time. Subsequent compilation of our present findings with previously reported mutation data reveals that in a total of 287 Greek breast/ovarian cancer families, 46 and 13 carry a deleterious mutation in BRCA1 and BRCA2, respectively. It should be noted that two BRCA1 mutations, 5382insC and G1738R, both located in exon 20, account for 46% of the families found to carry a mutation. Based on our mutation analysis results, we propose here a hierarchical, cost-effective BRCA1/2 mutation screening protocol for individuals of Greek ethnic origin. The suggested protocol can impact on the clinical management of breast-ovarian cancer families on a national healthcare system level.

Cationic liposomes have been suggested as possible agents for nonviral gene transfer. The interaction of plasmid DNA (pDNA) with dispersions of stable unilamellar cationic liposomes based on the binary lipid system 1,2-dimyristoyl-3-trimethyl-ammonium-propane (DMTAP):1,2-dioleoyl-3-trimethyl-ammonium-propane (DOTAP) has been studied by using isothermal titration calorimetry (ITC), high-precision differential scanning calorimetry (DSC), dynamic light scattering (DLS), and circular dichroism (CD). Systematic calorimetric and DLS exploration of the DMTAP:DOTAP binary system reveals that single-bilayer liposomes are stable at the 4:1 molar ratio, exhibiting the main lipid-phase transition temperature at approximately 25.3 degrees C, and a total enthalpy change deltaH = 8.5 +/- 0.4 kcal/mol. The interaction of pDNA with unilamellar DMTAP:DOTAP vesicles was investigated by ITC experiments, which clearly distinguished endothermic binding between the phosphate and the ammonium groups from exothermic processes, driven by slow kinetics, corresponding to interliposomal, DNA-triggered aggregation that leads to the formation of large multilamellar liposome/pDNA assemblies. Lipid-added-to-pDNA and pDNA-added-to-lipid experiments have been carried out in order to systematically explore the interaction mechanisms. Complex ITC profiles are revealed, which may be linked to packing rearrangements of the pDNA molecules bound at the outer liposomal surface, possibly due to binding to more than one liposome or due to p-DNA-enhanced heterogeneity in the local lipid concentration. DNA-mediated aggregation effects are detected at high [ammonium]/[phosphate] molar ratios in the case of lipid-added-to-pDNA interactions and at relatively low [phosphate]/[ammonium] molar ratios in the case of pDNA-added-to-lipid.

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The prevalence of FP at the anomaly scan in an unselected low-risk population is not high (1.25%). Our data suggest that the risk of aneuploidy associated with isolated FP in a low-risk, unselected population is so small that it should not be an indication for invasive prenatal karyotyping.

Hereditary breast and ovarian cancer syndromes can be caused by loss-of-function germline mutations in one of the tumour suppressor genes BRCA1 and BRCA2. In order to characterize these mutations in the Greek population we have been collecting samples from breast/ovarian cancer patients with a family history in collaboration with a large number of Greek Hospitals. Our DNA bank contains samples from more than 300 patients, corresponding to approximately 250 families. In terms of family history this group consists of three subgroups: (i) very early onset (<30 yrs) without family history (10%); (ii) moderate family history (2 members affected, < 50 yrs) (40 %) (iii) strong family history (3'7 members affected) (50 %). Screening of BRCA1 and BRCA2 genes in 150 patients has revealed deleterious mutations in 39 unrelated patients. 5382insC has been found in 11 unrelated families. In summary, the mutation spectrum of BRCA1 and BRCA2 genes in the Greek population seems to be composed by an elevated frequency of 5382insC with the rest being novel or recurrent mutations with low frequency in both genes. Screening of BRCA1 gene is also in progress in collaboration with the Institute of Oncology and Radiology of Serbia. DNA samples have been collected from 32 Serbian families with a family history of breast ovarian cancer. Direct sequencing in exons 2, 5 and 20 of all these samples revealed only one deleterious mutation (C61G) in exon 5 of BRCA1 gene. Screening of the remaining exons is in progress.