Micronucleus frequency and BMI-1 expression analysis as two possible cytogenetic and molecular metastasis biomarkers in breast cancer

World Congress on Human Genetics

November 07- 08, 2016 Barcelona, Spain

Mahdieh Salimi, Elaheh Eskandari and Sepehr Sarraf Zadeh

National Institute of Genetic Engineering and Biotechnology, Iran

Posters & Accepted Abstracts: Human Genet Embryol

Abstract :

Breast cancer is a highly invasive and metastatic disease and known for its propensity to recur decades after treatment. Breast cancer cells that undergo epithelial-to-mesenchymal transition (EMT) obtain malignant characteristic, however, the molecular mechanism and/or cytogenetic characteristic underlying this transition are poorly understood. Breast cancer patients have a reduced DNA repair capacity. B-cell-specific Moloney murine leukemia virus integration site 1 (BMI-1) is a Polycomb group protein that is able to induce telomerase activity, enabling the immortalization of epithelial cells. Immortalized cells are more susceptible to double-strand breaks, which are subsequently repaired by homologous recombination. Overexpression of BMI-1 has been reported in various human cancers and proved to be associated with poor survival. Spontaneous and bleomycin-induced genomic instability and BMI-1 gene expression in peripheral blood of breast cancer patients compared with first degree relatives (FDR) and normal control were examined using the cytokinesis block micronuclei-cytome (CBMN cyt) and real-time RT-PCR assays, respectively. Possible association between these events and a series of clinical-pathological parameters of the tumors were studied. In spite of MN frequency with no association with lymph node involvement, the peripheral blood net frequency of micronuclei and BMI-1 expression were significantly higher in breast cancer patients with distant metastasis. BMI-1 expression level was higher in lymph node positive (LN+) breast cancer compared with LN negatives. 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.

Biography :

Email: salimi@nigeb.ac.ir