Tehran University of Medical Sciences Basic & Clinical Cancer Research 2228-6527 10 2 2018 05 22 25 32 EN Elaheh Eskandari Department of Medical Genetics, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran. Mahdieh Salimi Department of Medical Genetics, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran. Frouzandeh Mahjoubi Department of Medical Genetics, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran. 2018 01 04 2018 05 22 Background: Colorectal cancer (CRC) is one of the most common cancers worldwide and can be caused by a variety of genetic and acquired/environmental factors. Bax-interacting factor-1 (Bif-1) is an apoptosis inducer gene that interacts with the Bcl2 protein family and triggers apoptosis via direct contact or by changing into the Bax protein conformation using the phosphorylation mechanism. Bif-1 also interacts with Beclin-1, a protein that plays a central role in autophagy through mediation of UVRAG (ultraviolet irradiation resistant-associated gene), a positive regulator of phosphatidylinositol 3-kinase complex 3 (PI3KC3), thereby inducing autophagy in mammalian cells. Considering the dual role of Bif-1 in many tumors of different origins, in this study we assessed Bif-1 gene expression to investigate its potential role as a possible prognostic biomarker in Iranian colorectal cancer patients. Methods: Bif-1 gene expression in tumors and normal adjacent tissues in 50 colorectal cancer patients were quantified using Real-time RT-PCR. Also, the association between Bif-1 gene expression levels with the histopathological characteristics of patients was assessed. Results: The results indicated an overall upregulation of the Bif-1 gene in colorectal tumors compared with normal adjacent tissues (p < 0.0001). Also, Bif-1expression was significantly elevated in stages II and III compared with stage I, and down-regulated in stage IV patients with distant metastasis. A positive association was also observed between lymph node involvement and tumor size ≥ 5 centimeters with Bif-1 overexpression (P < 0.001). Conclusion: In conclusion, up-regulation of the Bif-1 gene could be considered as a possible prognostic candidate in colorectal cancers associated with nodal metastasis and greater tumor size. Further validation of these results are recommended in studies with larger sample sizes. https://bccr.tums.ac.ir/index.php/bccrj/article/view/268 https://bccr.tums.ac.ir/index.php/bccrj/article/download/268/04