Gene expression profile of myoepithelial progenitor cells

There is increasing evidence that breast and other cancers originate from and are maintained by a small fraction of stem/progenitor cells with self-renewal properties. Whether such cancer stem/progenitor cells originate from normal stem cells based on initiation of a de novo stem cell program, by reprogramming of a more differentiated cell type by oncogenic insults or both remains unresolved. A major hurdle in addressing these issues is lack of immortal human stem/progenitor cells that can be deliberately manipulated in vitro. Here we discribe Myoepithelial Progenitor Cells (MPCs) that show properties of EMT and claudin low subtype of breast cancers. Through microarray analysis, we have found that these K5-/K19- cells show similar gene expression pattens of the claudin-low subtype of breast cancer. Normal human mammary epithelial cells (hMECs) were isolated from Reduction Mammoplasty and immortalized by human telomerase (hTERT). Type III- K5-/K19- cell colonies were isolated from K5+/K19- immortalized hMECs and cultured in MEGM medium for self-renewal and differentiation. Total RNA isolated from Type III cells were used on Affymetrix microarray.