title: Facile whole mitochondrial genome resequencing from nipple aspirate fluid using MitoChip v2.0.
abstract: BACKGROUND
  Mutations in the mitochondrial genome (mtgenome) have been associated with many disorders, including breast cancer. Nipple aspirate fluid (NAF) from symptomatic women could potentially serve as a minimally invasive sample for breast cancer screening by detecting somatic mutations in this biofluid. This study is aimed at 1) demonstrating the feasibility of NAF recovery from symptomatic women, 2) examining the feasibility of sequencing the entire mitochondrial genome from NAF samples, 3) cross validation of the Human mitochondrial resequencing array 2.0 (MCv2), and 4) assessing the somatic mtDNA mutation rate in benign breast diseases as a potential tool for monitoring early somatic mutations associated with breast cancer.
  
  
  METHODS
  NAF and blood were obtained from women with symptomatic benign breast conditions, and we successfully assessed the mutation load in the entire mitochondrial genome of 19 of these women. DNA extracts from NAF were sequenced using the mitochondrial resequencing array MCv2 and by capillary electrophoresis (CE) methods as a quality comparison. Sequencing was performed independently at two institutions and the results compared. The germline mtDNA sequence determined using DNA isolated from the patient's blood (control) was compared to the mutations present in cellular mtDNA recovered from patient's NAF.
  
  
  RESULTS
  From the cohort of 28 women recruited for this study, NAF was successfully recovered from 23 participants (82%). Twenty two (96%) of the women produced fluids from both breasts. Twenty NAF samples and corresponding blood were chosen for this study. Except for one NAF sample, the whole mtgenome was successfully amplified using a single primer pair, or three pairs of overlapping primers. Comparison of MCv2 data from the two institutions demonstrates 99.200% concordance. Moreover, MCv2 data was 99.999% identical to CE sequencing, indicating that MCv2 is a reliable method to rapidly sequence the entire mtgenome. Four NAF samples contained somatic mutations.
  
  
  CONCLUSIONS
  We have demonstrated that NAF is a suitable material for mtDNA sequence analysis using the rapid and reliable MCv2. Somatic mtDNA mutations present in NAF of women with benign breast diseases could potentially be used as risk factors for progression to breast cancer, but this will require a much larger study with clinical follow up.
authors.affiliation: Cipher Systems, Crofton, USA. johnjakupciak@verizon.net
authors.forename: John P
authors.initials: JP
authors.lastname: Jakupciak
authors.forename: Andrea
authors.initials: A
authors.lastname: Maggrah
authors.forename: Samantha
authors.initials: S
authors.lastname: Maragh
authors.forename: Jennifer
authors.initials: J
authors.lastname: Maki
authors.forename: Brian
authors.initials: B
authors.lastname: Reguly
authors.forename: Katrina
authors.initials: K
authors.lastname: Maki
authors.forename: Roy
authors.initials: R
authors.lastname: Wittock
authors.forename: Kerry
authors.initials: K
authors.lastname: Robinson
authors.forename: Paul D
authors.initials: PD
authors.lastname: Wagner
authors.forename: Robert E
authors.initials: RE
authors.lastname: Thayer
authors.forename: Ken
authors.initials: K
authors.lastname: Gehman
authors.forename: Teresa
authors.initials: T
authors.lastname: Gehman
authors.forename: Sudhir
authors.initials: S
authors.lastname: Srivastava
authors.forename: Alioune
authors.initials: A
authors.lastname: Ngom
authors.forename: Gabriel D
authors.initials: GD
authors.lastname: Dakubo
authors.forename: Ryan L
authors.initials: RL
authors.lastname: Parr
mesh_terms: D000328:Adult; D001707:Biopsy, Needle; D001826:Body Fluids / Q000737:chemistry / Q000166:cytology*; D001941:Breast Diseases / Q000097:blood / Q000235:genetics*; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000032:analysis*; D005240:Feasibility Studies; D005260:Female; D054629:Genome, Mitochondrial; D006801:Humans; D008875:Middle Aged; D008928:Mitochondria / Q000235:genetics*; D009558:Nipples / Q000473:pathology*; D020411:Oligonucleotide Array Sequence Analysis
chemical_list: D004272:DNA, Mitochondrial