Is SPAG9 a Candidate Diagnostic/Prognostic Biomarker in Breast Cancer

Introduction & Aim: Breast cancer is the most common malignancy in women worldwide. Latest statistics related to 2012 shows that, 1.7 million women were diagnosed with breast cancer in that year. Also, breast cancer was the fifth cause of cancer death worldwide in 2012. Statistics of breast cancer incidence and mortality among Iranian women reports that breast cancer occurrence rate is growing and there are nearly 10,000 new cases each year which 1063 cases cause to death. Cancer biomarkers can be used for estimating risk of disease, distinguishing benign from malignant, determining prognosis and prediction and monitoring status of the cancer. Either they can be applied to detect recurrence or determine response or progression to therapy. The aim of this project was to investigate the potential of SPAG9 gene as a biomarker in breast cancer.Further, we wished to find any significant association between SPAG9 expression and clinicopathologic variables.Methods: To explore SPAG9 mRNA expression, 35 breast cancer tissues together with 35 adjacent noncancerous tissues (ANCTs) were collected and examined using RT-PCR. Statistical analysis was done utilizing SPSS 22.0 software.Results: SPAG9 mRNA expression was detected in 57.1% of cancerous tissues and amazingly in 42.9% of ANCTs. Further, statistical analysis showed significant correlation between SPAG9 expression with tumor size and lymph node metastasis. Conclusion: SPAG 9 is a cancer testis antigen (CTA) which in theory must not be detected in normal tissues except testis and cancer cells. Surprisingly, the expression of this gene was detected in about 42% of normal adjacent tissues. Therefore, the role of this gene as a CTA is under question. In addition, since our data demonstrates expression of SPAG9 in both cancerous and ANCTs, this gene may not be used as a diagnostic biomarker. However, correlation between SPAG9 expression with tumor size and lymph node metastasis suggests that SPAG9 may be a suitable prognostic biomarker

Keywords:

SPAG9 , CTA , Breast Cancer , Biomarker , RT-PCR