Mohsen Omrani - Cellular and Molecular Research Center, Zahedan University of Medical Sciences, Zahedan, Iran. Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences,Zahedan, Iran
Mohammad Hashemi - Cellular and Molecular Research Center, Zahedan University of Medical Sciences, Zahedan, Iran. Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences,Zahedan, Iran
Ebrahim Eskandari-Nasab - Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences,Zahedan, Iran

Background: MDM2 (Murine Double Minute-2) is an oncoprotein that inhibits the P53 activity.Overexpression of MDM2 gene has been reported in several human tumors. In the present study we aimed to evaluate the impact of 40-bp insertion/deletion (ins/del) polymorphism in the promoter ofMDM2 and susceptibility to breast cancer in a sample of Iranian population. Methods: This case-control study was done on 236 patients with breast cancer and 203 healthy individuals. The 40-bp ins/del polymorphism was determined by using polymerase chain reaction method.Results: The findings indicated that MDM2 ins/del variant increased the risk of breast cancer in codominant (OR=2.09, 95%CI=1.14-3.85, P=0.018, del/del vs ins/ins), dominant (OR=1.49, 95%CI=1.02-2.18, P=0.038, ins/del+del/del vs ins/ins) and recessive (OR=1.86, 95%CI=1.03-3.34, P=0.038, del/del vs ins/ins+ins/del) tested inheritance models. The del allele increased the risk of breast cancer (OR= 1.48, 95% CI=1.11-1.98, P=0.008) compared with ins allele.Conclusions: Our result revealed that 40-bp ins/del polymorphism in the promoter of MDM2 increased the risk of breast cancer in an Iranian population. Further investigations with larger sample sizes and diverse ethnicities are needed to verify our findings.

Breast cancer, MDM2, insertion ، deletion, polymorphism