TOP2A gene encodes a DNA topoisomerase that participates in processes such as chromosomal concentration, chromatid separation, and release of torsional stress during DNA transcription and replication. The gene encoding this form, TOP2α, is located on chromosome 17, the beta gene located on chromosome 3, and multiple mutations in the TOP2α gene are involved in development.
TOP2A gene amplification probe uses the orange-red dye to label the TOP2A gene region, and the green dye to label the chromosome 17 centromere region (CEP17). TOP2A gene-labeled region is located at 17q21.2, and the CEP17 probe adopts an alpha satellite sequence, which has extremely high specificity and does not hybridize with other chromosome centromeres to produce noisy spots.
Patients with abnormal TOP2A gene indicates a shorter recurrence-free survival, and patients with TOP2A gene deletion have a worse prognosis. In the study of advanced breast cancer, it was found that the abnormality of TOP2A gene was significantly correlated with the protein expression and the sensitivity of tumor cells to anthracyclines. Therefore, the detection of TOP2A gene status has guiding significance for the treatment and prognosis of breast cancer.
