Upregulation of RHOXF2 and ODF4 Expression in Breast Cancer Tissues

OBJECTIVE During the past decade, the importance of biomarker discovery has been highlighted in many aspects of cancer research. Biomarkers may have a role in early detection of cancer, prognosis and survival evaluation as well as drug response. Cancer-testis antigens (CTAs) have gained attention as cancer biomarkers because of their expression in a wide variety of tumors and restricted expression in testis. The aim of this study was to find putative biomarkers for breast cancer. MATERIALS AND METHODS In this applied-descriptive study, the expression of 4 CTAs, namely acrosin binding protein (ACRBP), outer dense fiber 4 (ODF4), Rhox homeobox family member 2 (RHOXF2) and spermatogenesis associated 19 (SPATA19) were ana- lyzed at the transcript level in two breast cancer lines (MCF-7 and MDA-MB-231), 40 invasive ductal carcinoma samples and their adjacent normal tissues as well as 10 fibroadenoma samples by means of quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). RESULTS All four genes were expressed in both cell lines. Expression of ODF4 and RH- OXF2 was detected in 62.5% and 60% of breast cancer tissues but in 22.5 and 17.5% of normal tissues examined respectively. The expression of both RHOXF2 and ODF4 was upregulated in cancerous tissues compared with their normal adjacent tissues by 3.31 and 2.96-fold respectively. The expression of both genes was correlated with HER2/neu overexpression. RHOXF2 expression but not ODF4 was correlated with higher stages of tumors. However, no significant association was seen between expression patterns and estrogen and progesterone receptors status. CONCLUSION ODF4 and RHOXF2 are proposed as putative breast cancer biomarkers at the transcript level. However, their expression at protein level should be evaluated in future studies.