Association of Elevated Peripheral Blood Micronucleus Frequency and Bmi-1 mRNA Expression with Metastasis in Iranian Breast Cancer Patients

Document Type : Research Articles


Department of Medical Genetics, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran.


Background: In order to find cytogenetic and molecular metastasis biomarkers detectable in peripheral blood the
spontaneous genomic instability expressed as micronuclei and Bmi-1 expression in peripheral blood of breast cancer
(BC) patients were studied in different stages of the disease compared with unaffected first-degree relatives (FDRs)
and normal control. Methods: The Cytokinesis Block Micronuclei Cytome (CBMN cyt) and nested real-time Reverse
Transcription-Polymerase Chain Reaction (RT-PCR) assays, were respectively used to measure genomic instability and
Bmi-1 gene expression in 160 Iranian individuals comprised of BC patients in different stages of the disease, unaffected
FDRs and normal control groups. Result: The frequency of micronuclei and Bmi-1 expression were dramatically higher
in distant metastasis compared with non-metastatic BC. In spite of micronucleus frequency with no association with
lymph node (LN) involvement and hormone receptor status, the Bmi-1 expression level was higher in LN positive and
triple negative patients. Conclusion: Our results indicate that increased genomic instability expressed as micronuclei and
higher Bmi-1 expression in peripheral blood are associated with metastasis in breast cancer. Therefore implementation
of micronucleus assay and Bmi-1 expression analysis in blood as possible cytogenetic and molecular biomarkers in
clinical level may potentially enhance the quality of management of patients with breast cancer.


Main Subjects

Volume 19, Issue 10
October 2018
Pages 2723-2730
  • Receive Date: 28 June 2017
  • Revise Date: 04 August 2018
  • Accept Date: 06 September 2018
  • First Publish Date: 01 October 2018