title: Assessment of circulating serum DNA integrity in colorectal cancer patients.
abstract: Background /Aim: Studies evaluating the integrity of cell-fee DNA (cfDNA) in colorectal cancer (CRC) have led to inconsistent results. Herein, we analyzed the utility of two different DNA integrity indexes (ACTB(384)/ACTB(106) and ALU(247)/ALU(115)) to assess cfDNA fragmentation in Turkish CRC patients. The correlation of circulating nucleosomes (cNUC) with the fragment sizes was also evaluated.
  
  
  METHODS
  Seventy two CRC patients and 42 CRC-free control individuals were enrolled in the study. cfDNA was analyzed by quantitative polymerase chain reaction (qPCR).
  
  
  RESULTS
  While with ALU(247)/ALU(115)there was a small difference between the groups, an approximately 3-fold (median values=0.12 and 0.34) lower integrity was found in the patients using the ACTB(384)/ACTB(106) ratio (p=0.06). The correlation between cNUC and qPCR threshold cycles was much higher for shorter fragments.
  
  
  CONCLUSIONS
  Lower DNA integrity and the predominance of mononuclesomes in serum reveal high fragmentation of cfDNA in CRC patients.
authors: Department of Basic Oncology, Oncology Institute, Istanbul University, Istanbul, Turkey.
authors: Ebru E
authors: EE
authors: Yörüker
authors: Department of Basic Oncology, Oncology Institute, Istanbul University, Istanbul, Turkey.
authors: Emre
authors: E
authors: Özgür
authors: Department of General Surgery, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey.
authors: Metin
authors: M
authors: Keskin
authors: Department of Basic Oncology, Oncology Institute, Istanbul University, Istanbul, Turkey.
authors: Nejat
authors: N
authors: Dalay
authors: Institute of Clinical Chemistry and Pharmacology, University of Bonn, Bonn, Germany.
authors: Stefan
authors: S
authors: Holdenrieder
authors: Department of Basic Oncology, Oncology Institute, Istanbul University, Istanbul, Turkey ugurd@istanbul.edu.tr.
authors: Ugur
authors: U
authors: Gezer
mesh_terms: D000199:Actins / Q000235:genetics*; D000328:Adult; D000368:Aged; D020087:Alu Elements / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000097:blood* / Q000235:genetics / Q000473:pathology; D053938:DNA Fragmentation; D004273:DNA, Neoplasm / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating
chemical_list: D000199:Actins; D004273:DNA, Neoplasm
keywords: DNA integrity; circulating cell-free DNA; circulating nucleosomes; colorectal cancer