Investigation of Exportin 5 (XPO5) mRNA expression in breast cancer patients

Background and objectives: Deregulation in the expression of microRNAs is involved in the pathogenesis of various malignancies. Impaired microRNAs processing pathway is one possible mechanism for global deregulation of the miRNAs. Exportin 5 (XPO5) is a key member of this pathway that links nuclear and cytoplasmic steps of miRNAs biogenesis together. XPO5 deregulation has been reported in some cancers but very little is known about its role in breast cancer. Therefore, this study aimed to evaluate the mRNA expression of XPO5 in breast cancer in an Iranian population. Methods: In this case-control study, 30 tumoral tissues and 30 tumor-free margins were collected from breast cancer patients. After RNA extraction and cDNA synthesis, XPO5 mRNA expression level was assessed using quantitative Real-Time PCR. Results: Our results showed that XPO5 was overexpressed in 53.3% of tumoral tissues but the difference in the gene expression level between tumoral tissues and tumor-free margins was not statistically significant (P-value=0.834). XPO5 expression level showed no statistically significant correlation and association with clinical and pathological parameters. Conclusion: Overexpression of XPO5 in large percent of patients indicates that high level of XPO5 expression may be a tumorigenic factor for breast cancer which needs to be investigated more deeply