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 analyzed
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 RHOXF2
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