Tamoxifen Prefabricated Beige Adipose Tissue Improves Fat Graft Survival in Mice

Background: Fat grafting has become an important tool for breast reconstruction in breast cancer patients. Tamoxifen is the hormone therapy agent most frequently used for breast cancer. Moreover, tamoxifen can affect adipose metabolism and cause browning of adipose tissue. This study hypothesized that tamoxifen could increase fat graft survival by altering adipose metabolism. Methods: C57/BL6 mice were divided into three groups receiving different treatments before and after fat grafting. The Tam-Graft-Tam group was pre-treated with daily tamoxifen for 8 weeks, received fat grafting, and was treated with daily tamoxifen. The Graft-Tam group was pre-treated with daily PBS for 8 weeks, received fat grafting, and was treated with daily tamoxifen. The Control group was pre-treated with daily PBS for 8 weeks, received fat grafting, and was treated with daily PBS. The inguinal fat used for transplantation and the transferred fat at Weeks 4 and 12 post-transplantation was harvested and analyzed. Results: Inguinal fat pre-treated with tamoxifen showed beige fat features, with smaller adipocyte size, up-regulated UCP-1 expression, and improved vascularization. The retention rate of transferred fat was significantly higher in the Tam-Graft-Tam than in the Control group (69±12 % vs. 36±13 %, p0.05). Improved angiogenesis and increased VEGF expression were found in Tam-Graft-Tam group, but not in the Graft-Tam group. Conclusion: Tamoxifen treatment before fat grafting resulted in prefabricated vascularized beige fat with small-sized adipocytes, which greatly improve fat graft survival. However, tamoxifen administration after fat grafting did not affect fat graft evolution. 1 These authors made an equal contribution to the manuscript. >2 Feng Lu and Yunjun Liao should be co-corresponding author Financial Disclosure This work was supported by the National Nature Science Foundation of China (81471881, 81372083), the Key Clinical Specialty Discipline Construction Program, Health Collaborative Innovation major projects of Guangzhou (7414275040815), the Natural Science Foundation of Guangdong Province of China (2014A030310155), the Entry Point Project of Guangdong Province of China (PY2014N036), the Innovative project of Guangdong Province of China (2014KQNCX046), and the Administrator Foundation of Nanfang Hospital (2014B009). Corresponding author: Dr. Feng Lu, Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, 1838 Guangzhou North Road, Guangzhou, Guangdong 510515, P. R. China.Phone/ fax : +86 (020) 61641869 ; E-mail : doctorlufeng@hotmail.com Dr. Yunjun Liao, Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, 1838 Guangzhou North Road, Guangzhou, Guangdong 510515, P. R. China. Phone/ fax : +86 (020) 61641869; E-mail: yunjun1000@sina.com ©2017American Society of Plastic Surgeons