title: [The relationship between copy number and microsatellite instability of mitochondrial DNA in colorectal cancer].
abstract: OBJECTIVE
  To study the relationship between the abnormality of mitochondrial DNA (mtDNA) copy number and the clinical parameters and microsatellite instability (MSI) in colorectal cancer.
  
  
  METHODS
  Total DNA was extracted from cancer and pericancer tissue from 50 colorectal cancer (CRC) biopsy samples. Non-coding region sequencing was done and the copy number of mtDNA was quantitated with real-time PCR in mitochondrial ND1 gene. The relationship between clinical indicators, mtMSI and mitochondrial copy number was detected.
  
  
  RESULTS
  The mean copy number of mtDNA 312 +/- 185 in the tumor tissue was significantly lower than that 525 +/- 125 of the corresponding non-tumor tissue of these patients (P < 0.001). No significant correlation was found between mtDNA copy number and other variables including age, gender, pathological type and clinical stage (P > 0.05). However, there was a significant correlation between copy number and mtMSI (P < 0.001).
  
  
  CONCLUSIONS
  There is a significant reduction of mtDNA in CRC patients, which may be caused by mtMSI.
authors.affiliation: Department of Gastroenterology, the 305 Hospital of PLA, Beijing 100017, China. hp_20050909@126.com
authors.forename: Ping
authors.initials: P
authors.lastname: Huang
authors.forename: Yun-xin
authors.initials: YX
authors.lastname: Zhang
authors.forename: Ting
authors.initials: T
authors.lastname: Zhao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D009154:Mutation; D016133:Polymerase Chain Reaction / Q000379:methods
chemical_list: D004272:DNA, Mitochondrial