Qian Geng ¹, Haoyu Peng ¹, Rongcheng Luo ¹,Fengsheng Chen ¹, Rong Li ²

¹ Department of Oncology, TCM-Integrated Cancer Center of SouthernMedical University, Guangzhou. ² Department of Oncology, Southern Medical University NanfangHospital, Guangzhou.

Objective：Sirt7,as one of the seven Sirtuin family members,which plays distinct roles in cancerprogression,is bringing emerging attention due to its oncogenic characteristic.The expression of Sirt7 in breast cancer remained unclear,and the aim of thisstudy was to elucidate its role in breast cancer. Method：Atotal of 188 casesincluded in this study were immunohistochemically evaluatedfor Sirt7, and western blot assay was used to assessits expression in breastcell lines as well as 36 breast cancer tissues and 36 paired non-canceroustissues. Result：Results：Upregulationof Sirt7 was found in breast cancer cell lines and breast cancer tissues (P<0.001) by western blotanalysis.Sirt7 was highly expressed in breast cancer tissue samples (67.8%) compared toadjacent normal breasttissues (31.8%) by immunohistochemical assay. It was alsoobserved that the high expression level of Sirt7 wassignifiantly correlatedwith high histological grade (P=0.039) and negatively related to overallsurvival (P=0.006).Sirt7 proved to be an independent prognostic factor (P=0.007)in breast cancer. Conclusion：Sirt7expression wasimplicated with high histological grade and independentlypredicted poor clinical outcome in patients with breastcancer, suggesting thatSirt7 might play a role in the malignant progression of breast cancer.

Key words：Breastcancer   immunohistochemistry    oncogenes tumor