GNPS - The adipose microenvironment dysregulates the mammary myoepithelial cells and could participate to the progression of breast cancer

Overweight and obesity are now recognized as established risk factors for breast cancer in postmenopausal women. Reciprocal interactions have been described between adipose and cancer cells. Among the cell types present in the breast, myoepithelial cells (MECs) are considered "tumour suppressor" cells. During the transition from ductal carcinoma in situ to invasive cancer, disorganization or even the disappearance of MECs is observed. As the adipose microenvironment is now considered as a central actor in the progression of breast cancer, our objective was to evaluate if it could be involved in MEC functional modifications, leading to the transition of in situ to invasive carcinoma, particularly in obese patients. Through a co-culture model, we found that adipose cells could decrease the viability of the MECs. The adipose cells could also disrupt the expression of the genes involved in the maintenance of the extracellular matrix and to amplify the expression of leptin and inflammatory markers. The metabolite analyses revealed specific profiles that may be involved in the growth of neoplastic cells. All of these perturbations could thus be responsible for the loss of tumour suppressor status of MECs and promote the transition from in situ to invasive carcinoma.