title: Circulating cell-free DNA in serum as a biomarker of colorectal cancer.
abstract: OBJECTIVE
  The aim of this study was to report circulating cell-free DNA using ALU247 and ALU247/ALU115 biomarkers in serum of operated and non-operated patients with colorectal cancer (CRC).
  
  
  METHODS
  To undertake this, 90 blood samples were collected, including 30 samples from healthy volunteers; 27 samples from CRC non-operated patients and 33 samples from CRC-operated patients. Circulating cell-free DNA was verified through quantitative real-time PCR (qPCR) using ALU115 and ALU247 primers.
  
  
  RESULTS
  With regard to the ALU115-qPCR biomarker, the increased levels of circulating cell-free DNA in serum of non-operated patients were significant when compared with control (p<0.05). Moreover, levels of ALU247-qPCR biomarker were statistically significant between non-operated versus operated and non-operated versus control groups (p=0.000). With regard to the ALU247/115-qPCR biomarker, significant differences were observed between control versus non-operated patients (p=0.019), operated versus non-operated patients (p=0.005) and control versus operated patients (p=0.043).
  
  
  CONCLUSIONS
  Thus, the ALU247 and ALU247/ALU115-qPCR biomarkers may be important in detecting and monitoring CRC patients in both early and late stages.
authors.affiliation: Departament of Genetics, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceió, Brazil.
authors.forename: Benisio Ferreira
authors.initials: BF
authors.lastname: da Silva Filho
authors.forename: Ana Pavla Almeida Diniz
authors.initials: AP
authors.lastname: Gurgel
authors.forename: Manoel Álvaro de Freitas Lins
authors.initials: MÁ
authors.lastname: Neto
authors.forename: Dalmo Almeida
authors.initials: DA
authors.lastname: de Azevedo
authors.forename: Antonio Carlos
authors.initials: AC
authors.lastname: de Freitas
authors.forename: Jacinto da Costa
authors.initials: Jda C
authors.lastname: Silva Neto
authors.forename: Luiz Antonio Ferreira
authors.initials: LA
authors.lastname: Silva
mesh_terms: D000230:Adenocarcinoma / Q000097:blood / Q000175:diagnosis*; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D015179:Colorectal Neoplasms / Q000097:blood / Q000175:diagnosis*; D004247:DNA / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged
chemical_list: D015415:Biomarkers; D004247:DNA
keywords: Colorectal Cancer; Molecular Pathology; PCR