"BIK/NBK Gene Expression as a Possible Marker of Circulating Breast Cancer Cells in Blood"

The detection of circulating breast cancer cells in blood could be of special interest as an indicator of diagnosis and prognosis, and for the selection of treatment. In a previous report, our research group determined gene expression pro- files in samples of breast cancer tissue, identifying over-expression of the BIK/NBK mRNA gene in 90% of the analyzed samples. In this paper, we analyze the BIK/NBK gene expression as a possible biomarker of circulating breast cancer cells in blood. We demonstrate that the BIK/NBK gene expression is not a significant biomarker in the detection of circulating breast cancer cells in the blood of women with breast cancer. Several studies have evaluated the regulation of apoptosis by estrogens in breast cancer cells, demonstrating the importance of BIK/NBK protein, in estrogen-regulated breast cancer cell apoptosis, which suggests that the regulation of its expression may be an important therapeutic target or strategy in the management of cancer, and, although we did not find statistically significant differences among the patient groups to demonstrate that BIK/NBK gene expression is a biomarker of circulating breast cancer cells in blood, we consider it neces- sary to continue the study of this gene in breast cancer tissue and its role in the development and progression of breast cancer, its prognostic value, and its potential use as therapeutic target.