Implications of Topoisomerase (TOP1 and TOP2α) Expression in Patients With Breast Cancer

In Vivo. 2020 Nov-Dec;34(6):3483-3487. doi: 10.21873/invivo.12188.

Abstract

Background/aim: We evaluated the usefulness of topoisomerases (TOPs) expression as prognostic predictors in breast cancer.

Patients and methods: We retrospectively investigated sixty cases with primary breast cancer. We evaluated the tumor and non-tumor mRNA levels of TOP1 and TOP2α using quantitative reverse-transcription polymerase chain reaction. TOP1/TOP2α positivity was defined as the ratio of the mRNA expression of cancer/normal tissue of >1 for both TOP1 and TOP2α.

Results: TOP1 and TOP2α were markedly overexpressed in breast cancer tissues compared to normal breast tissues. Of the 60 cases, 46 (76.7%) were positive for TOP1/TOP2α. The relapse-free survival was relatively shorter for patients with positive TOP1/TOP2α. There was no recurrent disease among the 14 patients who were negative for TOP1/TOP2α, whereas four of the 46 TOP1/TOP2α-positive patients had disease recurrence.

Conclusion: Negative TOP1 or TOP2α expression may be useful for predicting better prognoses in breast cancer patients.

Keywords: Topoisomerase I; breast cancer; topoisomerase II alpha.

MeSH terms

  • Breast Neoplasms* / genetics
  • DNA Topoisomerases, Type I* / genetics
  • DNA Topoisomerases, Type I* / metabolism
  • DNA Topoisomerases, Type II* / genetics
  • DNA Topoisomerases, Type II* / metabolism
  • Female
  • Humans
  • Neoplasm Recurrence, Local
  • Poly-ADP-Ribose Binding Proteins
  • Prognosis
  • Retrospective Studies

Substances

  • Poly-ADP-Ribose Binding Proteins
  • DNA Topoisomerases, Type I
  • TOP1 protein, human
  • DNA Topoisomerases, Type II
  • TOP2A protein, human