en زیست شناسی مولکولی Molecular biology پژوهشي Research <div style="text-align: justify;"><strong>Background:</strong> Lactoferrin is a glycoprotein with antimicrobial, antioxidant, immune-modulating, antiviral, and most importantly anticancer properties. In the present study, the effect of lactoferrin on breast cancer cell growth and the expression of <em>Bax</em> and <em>Bak</em> genes are evaluated.<br> <strong>Materials and Methods:</strong> MCF7 cells were cultured in a 96-well plate with 1&times;10⁵ cells in each well. Different lactoferrin concentrations of 0, 50, 300, 600, and 800 &mu;g/mL were added to each well in three replicates and the well was incubated for 24 hours. After treatment, cell survival was measured using the MTT assay. To determine the level of expression of <em>Bax</em> and <em>Bak</em> genes, the cells were treated with lactoferrin concentrations of 0, 50, and 800 &mu;g/mL in 2 replicates for 24 hours. Then RNA extraction was performed and cDNA was synthesized immediately and the expression of the genes in the presence of beta-actin reference gene and cyber-green fluorescence color was investigated with real-time reactions.<br> <strong>&nbsp;Results:</strong> The cells viability in lactoferrin concentrations of 0, 50, 300, 500 and 800 &mu;g/&mu;L were 100%, 94%, 83%, 62%, and 32%, respectively. The expression level of the <em>Bax</em> gene at a concentration of 50 &mu;g increased by 2.71 times and in 800 &mu;g concentration decreased by 0.88 times. Also, the expression level of the <em>Bak</em> gene at concentrations of 50 and 800 &mu;g increased by 1.23 and 1.0 fold, respectively. Statistical analysis of the data indicated that the expression levels of two genes at a concentration of 50 &mu;g/mL of lactoferrin significantly increased (P<0.01), compared to the control. The significance level in this study was set at < 0.05.<br> <strong>&nbsp;Conclusion:</strong> In this study, lactoferrin showed a growth inhibitory effect on breast cancer cells and increased the expression of <em>Bax </em>and <em>Bak</em> genes involved in apoptosis at a concentration of 50 &micro;g/mL.</div> : Anti‌cancer, Breast cancer, Bak gene, Bax gene, Lctoferrin 107 116 http://rmm.mazums.ac.ir/browse.php?a_code=A-10-726-3&slc_lang=en&sid=1 Amir Khalafi amir_khalafi1998@yahoo.com 10031947532846009063 10031947532846009063 Yes Department of Basic Sciences, Sari Agricultural Sciences and Natural Resources University, Sari, Iran. Fatemeh Moradian f.moradian@sanru.ac.ir 10031947532846009064 10031947532846009064 No Department of Basic Sciences, Sari Agricultural Sciences and Natural Resources University, Sari, Iran. Alireza Rafiei rafiei1710@gmail.com 10031947532846009065 10031947532846009065 No Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.