title: In vitro model for DNA double-strand break repair analysis in breast cancer reveals cell type-specific associations with age and prognosis.
abstract: 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.
authors: Department of Obstetrics and Gynecology, Ulm University, Germany; and.
authors: Miriam
authors: M
authors: Deniz
authors: Department of Obstetrics and Gynecology, Ulm University, Germany; and.
authors: Julia
authors: J
authors: Kaufmann
authors: Department of Obstetrics and Gynecology, Ulm University, Germany; and.
authors: Andreea
authors: A
authors: Stahl
authors: Department of Obstetrics and Gynecology, Ulm University, Germany; and.
authors: Theresa
authors: T
authors: Gundelach
authors: Department of Obstetrics and Gynecology, Ulm University, Germany; and.
authors: Wolfgang
authors: W
authors: Janni
authors: Institute of Medical Biostatistics, Epidemiology and Informatics, University Medical Centre, Johannes Gutenberg-University of Mainz, Germany.
authors: Isabell
authors: I
authors: Hoffmann
authors: Department of Obstetrics and Gynecology, Ulm University, Germany; and.
authors: Marlen
authors: M
authors: Keimling
authors: Department of Obstetrics and Gynecology, Ulm University, Germany; and.
authors: Stephanie
authors: S
authors: Hampp
authors: Department of Obstetrics and Gynecology, Ulm University, Germany; and.
authors: Michaela
authors: M
authors: Ihle
authors: Department of Obstetrics and Gynecology, Ulm University, Germany; and lisa.wiesmueller@uni-ulm.de.
authors: Lisa
authors: L
authors: Wiesmüller
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000235:genetics*; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001940:Breast / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics*; D045744:Cell Line, Tumor; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair / Q000502:physiology; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D059765:Homologous Recombination / Q000235:genetics; D006801:Humans; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D011379:Prognosis
chemical_list: D000246:Adenosine Diphosphate Ribose
keywords: PARP inhibition; aging; chemotherapy; epithelial-mesenchymal transition