Cancer cells are typically surrounded by stromal cells and embedded in extracellular matrix (ECM). The stromal compartment interacts with cancer cells to promote growth and metastasis. For decades, autologous fasciocutaneous flaps have been safely applied for breast reconstruction after mastectomy. In contrast, the safety of fat grafting (lipofilling) procedure has been under debate regarding the risk of cancer recurrence.
Harvested fat tissue (lipoaspirates) and dissected abdominal fat (DAF) were co-cultured with MCF-7 breast cancer cells. The vitality of MCF-7 cells was measured using AlamarBlue® consecutively for 5 days. ECM degradation was determined by detection of matrix metalloproteinase-1 (MMP-1) expression in MCF-7 cells. Integrin α2 was measured by Western blot to assess the degree of adhesion and motility of MFC-7 cells.
The MCF-7 proliferation increased substantially when co-cultured with fat tissue. However, there was no significant difference between the proliferation stimulating effects of lipoaspirates and DAF. Similarly, MMP-1 protein expression was equally elevated in MCF-7 cells by both lipoaspirates and DAF. Importantly, MCF-7 cells showed an increased level of integrin α2 once co-cultured with either lipoaspirates or DAF.
Fat tissue increases the proliferation of MCF-7 cells in vitro. Our data suggest that lipoaspirates as well as DAF might possess a considerable potency to promote tumorigenic growth of breast cancer cells. Thus, clinical trials are needed to address the safety of lipofilling by breast reconstruction surgery after mastectomy.