Preadipocytes stimulate breast cancer cell growth

Abstract

Mammary fat may affect human breast cancer development. In this study a novel coculture system was used to investigate stromal‐epithelial cell interactions in vitro. The extent of differentiation of a feeder layer of 3T3‐L1 preadipocytes affected the clonal growth of breast cancer cells under anchorage‐independent conditions. When the feeder‐layer preadipocytes were proliferating, the clonal growth of estrogen receptor‐positive MCF‐7 and estrogen receptor‐negative MDA‐MB‐231 and MDA‐MB‐436 cells was stimulated by 100%, 43%, and 60%, respectively. In contrast, after differentiation the feeder layer of mature adipocytes inhibited clonal growth of breast cancer cell lines by 60%. No clonal growth stimulation of human pancreatic (Panc‐1) or prostatic (PC‐3) cancer cells was noted when these cells were grown under identical conditions with a proliferating 3T3‐L1 cell feeder layer. These findings suggest that proliferating preadipocytes may be associated with factors that specifically stimulate breast cancer cell growth.