Mitochondrial D-loop Mutations as Clonal Markers in Multicentric Hepatocellular Carcinoma and Plasma

Clin Cancer Res. 2002 Feb;8(2):481-7.

Abstract

Purpose: Hepatocellular carcinoma (HCC) is a highly malignant tumor prone to multicentric occurrence. Differentiation between a true relapse of HCC and a second primary tumor is of clinical importance. We sought to identify mitochondrial mutations in HCC and test their use as clonal markers in this disease.

Experimental design: Primary HCC tissue samples were obtained from 19 patients and analyzed for mutations within the mitochondrial displacement loop (D-loop). The discovered mutations were used to determine tumor clonality and provided the basis for detection of tumor DNA in corresponding plasma samples.

Results: Thirteen of 19 HCC cases (68%) were identified as having D-loop mitochondrial DNA (mtDNA) mutations in at least one tumor. In 3 of these 13 cases, the same mutation was observed in multiple tumors, indicating monoclonal origin. Remarkably, in 8 of 13 mutated cases, we detected deletion/insertion mutations in the C-tract, a recently reported hotspot and potential replication start site of the closed, circular mitochondrial genome. In addition, we detected mutant mtDNA in 8 of 10 tested paired plasma DNA samples using a highly sensitivity molecular assay.

Conclusions: mtDNA mutations within the D-loop control region are a frequent event in HCC, providing a molecular tool for the determination of clonality. In addition, detection of tumor-specific mtDNA mutations in plasma DNA needs to be explored further for monitoring patients with primary HCC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Biomarkers, Tumor*
  • Carcinoma, Hepatocellular / blood*
  • Carcinoma, Hepatocellular / genetics*
  • DNA, Mitochondrial*
  • Female
  • Humans
  • Liver Neoplasms / blood*
  • Liver Neoplasms / genetics*
  • Male
  • Middle Aged
  • Mutation*
  • Oligonucleotides / metabolism
  • Polymerase Chain Reaction

Substances

  • Biomarkers, Tumor
  • DNA, Mitochondrial
  • Oligonucleotides