In vitro model for DNA double-strand break repair analysis in breast cancer reveals cell type-specific associations with age and prognosis.

Dysfunction of homologous recombination is a common denominator of changes associated with breast cancer-predisposing mutations. In our previous work, we identified a functional signature in peripheral blood lymphocytes from women who were predisposed that indicated a shift from homologous recombination to alternative, error-prone DNA double-strand break (DSB) repair pathways. To capture both hereditary and nonhereditary factors, we newly established a protocol for isolation and ex vivo analysis of epithelial cells, epithelial-mesenchymal transition cells (EMTs), and fibroblasts from breast cancer specimens (147 patients). By applying a fluorescence-based test system, we analyzed the error-prone DSB repair pathway microhomology-mediated end joining in these tumor-derived cell types and peripheral blood lymphocytes. In parallel, we investigated DNA lesion processing by quantitative immunofluorescence microscopy of histone H2AX phosphorylated on Ser139 focus after radiomimetic treatment. Our study reveals elevated histone H2AX phosphorylated on Ser139 damage removal in epithelial cells, not EMTs, and poly(ADP-ribose)polymerase inhibitor sensitivities, which suggested a DSB repair pathway shift with increasing patient age. Of interest, we found elevated microhomology-mediated end joining in EMTs, not epithelial cells, from patients who received a treatment recommendation of adjuvant chemotherapy, that is, those with high-risk tumors. Our discoveries of altered DSB repair activities in cells may serve as a method to further classify breast cancer to predict responsiveness to adjuvant chemotherapy and/or therapeutics that target DSB repair-dysfunctional tumors.-Deniz, M., Kaufmann, J., Stahl, A., Gundelach, T., Janni, W., Hoffmann, I., Keimling, M., Hampp, S., Ihle, M., Wiesmüller, L. In vitro model for DNA double-strand break repair analysis in breast cancer reveals cell type-specific associations with age and prognosis.

[Metformin for the treatment of polycystic ovary syndrome]. / Metformin bei polyzystischem Ovarsyndrom.

For several years there is an evidence for a relationship between the polycystic ovary syndrome (PCOS) and of insulin resistance; therefore metformin, an insulin sensitizer, is used for the treatment for more than 10 years. However, the evidence for metformin is assessed controversially. This review will give an overview about the data published on this topic.

Pre-pregnancy obesity compromises obstetric and neonatal outcomes.

OBJECTIVE: Obesity is an important issue among fertile women as it may affect obstetric and neonatal outcomes. METHODS: Obstetric and neonatal outcomes of primiparous women were retrospectively analyzed in non-obese (n=11387) and obese (n=943) women. A subgroup analysis was performed in obese women divided into three groups: Grade I obesity (Group A, n=654), Grade II obesity (Group B, n=192), and Grade III obesity (Group C, n=97). Odds ratios (OR) were expressed with the corresponding 95% confidence intervals (CI). RESULTS: The incidence of gestational diabetes (non-obese, 1.9%; obese, 7.6%; Group C, 19.6%) and preeclampsia (non-obese, 3.3%; obese, 13.5%; Group C, 17.5%) increased with rising weight. The risk of non-elective cesarean section was significantly higher in obese women than in non-obese women (21.7% vs. 13.2%). The risk of extreme preterm birth (before 28 weeks of gestation) doubled in the Grade I obesity group (OR, 2.1; 95% CI, 1.4-3.2) and nearly tripled in women with body mass index ≥35 kg/m2 (OR, 2.9; 95% CI, 1.7-4.9). CONCLUSION: Pre-pregnancy obesity is associated with higher incidences of gestational diabetes and preeclampsia. Our study shows that obese women have a higher risk of non-elective cesarean section and preterm birth.

Age-related activity of Poly (ADP-Ribose) Polymerase (PARP) in men with localized prostate cancer.

Mutations in DNA repair genes have been connected with familial prostate cancer and sensitivity to targeted drugs like PARP-inhibitors. Clinical use of this information is limited by the small fraction of prostate cancer risk gene carriers, variants of unknown pathogenicity and the focus on monogenic disease mechanisms. Functional assays capturing mono- and polygenic defects were shown to detect breast and ovarian cancer risk in blood-derived cells. Here, we comparatively analyzed lymphocytes from prostate cancer patients and controls applying a sensitive DNA double-strand break (DSB) repair assay and a flow cytometrybased assay measuring the activity of Poly(ADP-Ribose)-Polymerase, a target in treatment of metastatic prostate cancer. Contrary to breast and ovarian cancer patients, error-prone DNA double-strand break repair was not activated in prostate cancer patients. Yet, the activity of PARP discriminated between prostate cancer cases and controls. PARylation also correlated with the age of male probands, suggesting male-specific links between mutation-based and aging-associated DNA damage accumulation and PARP. Our work identifies prostate cancer-specific DNA repair phenotypes characterized by increased PARP activities and carboplatin-sensitivities, detected by functional testing of lymphocytes. This provides new insights for further investigation of PARP and carboplatin sensitivity as biomarkers in peripheral cells of men and prostate cancer patients.

Increased single-strand annealing rather than non-homologous end-joining predicts hereditary ovarian carcinoma.

Mutations in genes encoding DNA double-strand break (DSB) repair components, especially homologous recombination (HR) proteins, were found to predispose to breast and ovarian cancer. Beyond high penetrance risk gene mutations underlying monogenic defects, low risk gene mutations generate polygenic defects, enlarging the fraction of individuals with a predisposing phenotype. DSB repair dysfunction opens new options for targeted therapies; poly (ADP-ribose) polymerase (PARP) inhibitors have been approved for BRCA-mutated and platinum-responsive ovarian cancers. In this work, we performed functional analyses in peripheral blood lymphocytes (PBLs) using a case-control design. We examined 38 women with familial history of breast and/or ovarian cancer, 40 women with primary ovarian cancer and 34 healthy controls. Using a GFP-based test we analyzed error-prone DSB repair mechanisms which are known to compensate for HR defects and to generate chromosomal instabilities. While non-homologous end-joining (NHEJ) did not discriminate between cases and controls, we found increases of single-strand annealing (SSA) in women with familial risk vs. controls (P=0.016) and patients with ovarian cancer vs. controls (P=0.002). Consistent with compromised HR we also detected increased sensitivities to carboplatin in PBLs from high-risk individuals (P<0.0001) as well as patients (P=0.0011) compared to controls. Conversely, neither PARP inhibitor responses nor PARP activities were altered in PBLs from the case groups, but PARP activities increased with age in high-risk individuals, providing novel clues for differential drug mode-of-action. Our findings indicate the great potential of detecting SSA activities to deliver an estimate of ovarian cancer susceptibility and therapeutic responsiveness beyond the limitations of genotyping.