Differentiation of Human Induced Pluripotent Stem Cells to Mammary-like Organoids

TLDR

Human induced pluripotent stem cells can differentiate into diverse cell types and are promising for regenerative medicine and disease modeling. The authors first induced non‑neural ectoderm spheres (mEBs) from iPSCs with MammoCult medium, then differentiated 10‑day mEBs into mammary‑like organoids using a 3‑stage 3D floating mixed‑gel culture. The resulting organoids expressed luminal, basal, and estrogen‑receptor markers, produced milk protein, and provide an iPSC‑based model for studying mammary cell fate and breast disease.

Abstract

Human induced pluripotent stem cells (iPSCs) can give rise to multiple cell types and hold great promise in regenerative medicine and disease-modeling applications. We have developed a reliable two-step protocol to generate human mammary-like organoids from iPSCs. Non-neural ectoderm-cell-containing spheres, referred to as mEBs, were first differentiated and enriched from iPSCs using MammoCult medium. Gene expression profile analysis suggested that mammary gland function-associated signaling pathways were hallmarks of 10-day differentiated mEBs. We then generated mammary-like organoids from 10-day mEBs using 3D floating mixed gel culture and a three-stage differentiation procedure. These organoids expressed common breast tissue, luminal, and basal markers, including estrogen receptor, and could be induced to produce milk protein. These results demonstrate that human iPSCs can be directed in vitro toward mammary lineage differentiation. Our findings provide an iPSC-based model for studying regulation of normal mammary cell fate and function as well as breast disease development.