Fig. 1

Adipocytes change into CAAs in the invasive front of breast cancer. Normally, mature adipocytes and epithelial cells are separated by the basement membrane, limiting the possibility of interaction between both cell types. However, BC cells will directly expose to the TME containing adipocytes when BC cells break through the basement membrane. The adipocytes adjacent to the BC cells then change into CAAs, which are characterized by reduced volume, a gain of an irregular shape with smaller and dispersed lipid droplets, and have an important role in promoting progression and metastasis of BC. Abbreviations: BC, breast cancer; TME, tumor microenvironment; CAAs, cancer-associated adipocytes; ECM, extracellular matrix