BORIS a novel biomarker in breast cancer (A review article)

Introduction: The brother of the regulator of imprinted sites (BORIS) is a novel member of the cancer testis antigen gene family, which are normally expressed only in spermatocytes, but abnormally activated in different malignancies. Since BORIS has been identified in leukocytes of breast cancer patients, the present review investigates its value as a screening tool in early diagnosis of women with familial breast cancer. Material and Methods (Data Extraction): In this review, English studies Published from 2000 to 2013 in MEDLINE data base were identified and recruited. Articles were searched using the combination of the terms breast cancer , biomarker and BORIS . In addition, the bibliographies of selected references were searched and utilized. Results: BORIS is highly expressed in primary spermatocytes, although it is silenced at later stages ofspermatogenesis. BORIS has either not been found in normal human tissues or cells or has been detected at very low levels. The expression of the BORIS gene is predominantly controlled by DNA-methylation, while its activation requires the demethylation of its promoter. Re-expression of BORIS in cancers is due to the hypomethylation of its promoter. High expression of BORIS protein and RNA correlates with the tumour size and grade in cancer patients. High percentages of BORIS transcripts were detected in breast, endometrial, prostatic and colon cancer patients. Conclusion: The present survey indicates that while Breast cancer is the most common cancer in women and presently there are no early predictors for the detection of breast cancer, there is an urgent need to identify biomarkers which can complement or replace currently available diagnostic tools. Given that BORIS expression is high in women with familial risk of breast cancer, it may serves as a valuable marker in early cancer detection.

Keywords:

Breast cancer , Biomarker , BORIS