Novel stem cell line avoids risk of introducing transplanted tumors

Researchers describe a new "progenitor cell" capable of unlimited expansion and differentiation into mature kidney cells, but without the risk of forming tumors.

They engineered an in vitro microenvironment that permitted homogenous expansion of hPSC progenitor cells from the mesoderm - one of the three primary germ layers in early embryonic development. A germ layer is a primary layer of cells that form during embryogenesis. Progenitor cells are early descendants of stem cells, with more limited differentiation capacity.

Analyses showed that these newly created "mesoderm progenitors" lacked tumor-forming potential, but retained the capacity to differentiate into specific kinds of tissue, such as cells that comprise the adult kidney.

The researchers said the ability to generate expandable populations of progenitor cells with limited differentiation presents several advantages over the use of undifferentiated human stem cells:

First, cultures derived from the latter often harbor undifferentiated cells that retain the potential to seed tumor growth.

Second, development and manipulation of lineage-restricted progenitors is less elaborate. It's easier to create mature cell populations for research or therapeutic use.

Third, because progenitor cells are limited in what kind of cell they can be, they are less likely than stem cells to differentiate into an unwanted cell type.