Human lipogenesis with basic fibroblast growth factor gene transfected preadipocytes for breast reconstruction.

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 17591330
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: General surgery
• Research Institution: The Tazuke Kofukai (2006); Kyoto University (2005)
• Principal Investigator: INAMOTO Takashi The Tazuke Kofukai, Medical Research Institute, 5^<rd> Research Section, Chief Researcher, 医学研究所・第3研究部, 研究主幹 (10135577)
• Co-Investigator(Kenkyū-buntansha): KATO Hironori Kyoto University, Postgraduate School of Medicine, Assistant Professor, 医学研究科, 助手 (70324621)
• Project Period (FY): 2005 – 2006
• Keywords: fatty tissue / progenitor cell / bFGF / tissue regeneration / breast reconstruction

Research Abstract

1) Human stromal cells including preadipocytes which were separated from fatty tissue obtained at breast cancer operation were incubated and passed in vitro. Proliferation of stromal cells was preserved through 10^<th> passage. Basic fibroblast growth factor (bFGF) enhanced the proliferation of stromal cells. Cell yield exceeded 1000 times of the cell number at the beginning of culture. Cultured stromal cells maintained maturation activity to adipocyte at the initial level through 3^<rd> passage and declined thereafter. This result suggested that the optimal cell source for lipogenesis was 3^<rd> passage of cultured stromal cells.
2) Proliferation of stromal cells was enhanced when they were cutltured with autorogous serum compared with fetal calf serum (FCS). Effusion of axillary cavity after dissection of lymph nodes showed similar effect on the proliferation of stromal cells in vitro as FCS. This result suggested cultured stromal cells would proliferate in vivo.
3) 3^<rd> passage of s tromal cells cultured with bFGF was implanted with collagen disk scaffold incorporated by the microspheres containing bFGF into subcutaneous tissue of the back of nude mice. Adipogenesis at the implanted site of scaffold was evaluated histologically. Area of angiogenesis in 2 x 10^6 cultured stromal cell implant group was largest among groups implanted different number of cultured stromal cells, but area of adipogenesis expressing human vimentin was less than 1% of whole adipogenesis. In 8 x 10^6 cultured stromal cell implant group, area of human vimentin positive adipose tissue was 15% of whole adiopogenesis, although the area of whole adipogenesis was less than 2 x 10^6 cultured stromal cell implant group.
4) Initialially, b-FGF gene transfected using adenovirus vector, and obtained the result that stromal cells transfected b-FGF gene proliferated in vitro without exogenous b-FGF and differentiated into mature adipocytes. For future clinical application of this adipogenesis method, we are investigating a safe and efficient non-viral gene delivery system.