Stem Cell Reports Resource Analysis of Induced Pluripotent Stem Cells from a BRCA1 Mutant Family Abigail A. Soyombo, 1,7 Yipin Wu, 1,7 Lauren Kolski, 1 Jonathan J. Rios, 4 Dinesh Rakheja, 2,3 Alice Chen, 5 James Kehler, 5 Heather Hampel, 6 Alanna Coughran, 1 and Theodora S. Ross 1, * 1 Department of Internal Medicine, High Risk Cancer Genetics Program 2 Department of Pediatrics 3 Department of Pathology University of Texas Southwestern Medical Center, Dallas, TX 75390, USA 4 Sarah M. and Charles E. Seay Center for Musculoskeletal Research, Texas Scottish Rite Hospital for Children, Dallas, TX 75390, USA 5 Stemgent, Inc., San Diego, CA 92037, USA 6 Division of Human Genetics, Ohio State University, Columbus, OH 43240, USA 7 These authors contributed equally to this work *Correspondence: theo.ross@utsouthwestern.edu http://dx.doi.org/10.1016/j.stemcr.2013.08.004 This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-No Derivative Works License, which permits non-commercial use, distribution, and reproduction in any medium, provided the original author and source are credited. SUMMARY Understanding BRCA1 mutant cancers is hampered by difficulties in obtaining primary cells from patients. We therefore generated and characterized 24 induced pluripotent stem cell (iPSC) lines from fibroblasts of eight individuals from a BRCA1 5382insC mutant family. All BRCA1 5382insC heterozygous fibroblasts, iPSCs, and teratomas maintained equivalent expression of both wild-type and mutant BRCA1 transcripts. Although no difference in differentiation capacity was observed between BRCA1 wild-type and mutant iPSCs, there was elevated protein kinase C-theta (PKC-theta) in BRCA1 mutant iPSCs. Cancer cell lines with BRCA1 mutations and hormone-receptor- negative breast cancers also displayed elevated PKC-theta. Genome sequencing of the 24 iPSC lines showed a similar frequency of reprog- ramming-associated de novo mutations in BRCA1 mutant and wild-type iPSCs. These data indicate that iPSC lines can be derived from BRCA1 mutant fibroblasts to study the effects of the mutation on gene expression and genome stability. INTRODUCTION BRCA1/2 mutations are autosomal-dominant mutations that dramatically increase the risk for developing breast and ovarian cancer, and to a lesser extent other malig- nancies, such as melanoma, pancreatic cancer, and pros- tate cancer (Futreal et al., 1994; Lancaster et al., 1996; Miki et al., 1994). The BRCA1 and BRCA2 tumor-suppres- sor proteins play roles in transcriptional regulation and DNA repair (Turner et al., 2004). BRCA1 also participates in cell-cycle regulation (McPherson et al., 2004), polyade- nylation of messenger RNA (mRNA) (Kleiman et al., 2005), and ubiquitinylation (Baer and Ludwig, 2002). The cancers that arise in patients with inherited BRCA1 muta- tions appear to be more aggressive than those in patients with BRCA2 mutations or sporadic breast tumors. This aggressiveness is thought to result at least in part from the fact that BRCA1-deficient tumors, but not BRCA2-defi- cient tumors, are usually estrogen receptor (ER) and proges- terone receptor (PR) negative (Turner et al., 2004) and therefore unresponsive to hormonal therapies. These observations suggest that the shared DNA repair functions of BRCA1 and BRCA2 do not solely account for differences in cancer incidence among patients with mutations in these genes. Evidence also indicates that cancer risk differs depending on the location of the mutation in the BRCA sequences (Risch et al., 2006). Examination of different BRCA1/2 mutant cells that are prone to tumor formation will identify new BRCA1 and BRCA2 tumor-suppressor functions. One BRCA2 (BRCA2 6174 delT) and two BRCA1 (BRCA1 5382insC and BRCA1 185 delAG) founder mutations account for 90% of inherited BRCA1/2 mutations in patients of Ashkenazi Jewish descent (Petrucelli et al., 2010). Because 0.1% of the Ashkenazi population carries the BRCA1 5382insC mutation, we estimate that this muta- tion is present in approximately 10,000 individuals in the United States alone. A deeper understanding of how each of the Ashkenazi BRCA mutations leads to breast cancer is important because it will improve our understanding of phenotypic variabilities due to different mutations in the same gene. Although mice genetically engineered to have either Brca1 or Brca2 deficiency have been informative models for studies of breast cancer development (Drost et al., 2011; Drost and Jonkers, 2009; Evers and Jonkers, 2006; Shakya et al., 2011), differences in underlying biology exist between humans and mice. Thus, human models are necessary to complement animal models. It has been re- ported that mutation of a single BRCA1 allele leads to genomic instability in human cells, a phenomenon not observed in mice (Konishi et al., 2011). Generation of induced pluripotent stem cells (iPSCs) (Takahashi et al., 2007) from patients carrying BRCA1/2 mutations may pro- vide a window into the cellular phenotypic differences driving their increased cancer risk. BRCA1/2 mutant iPSC 336 Stem Cell Reports j Vol. 1 j 336–349 j October 15, 2013 j ª2013 The Authors