A step forward in stem cell research

According to research published today, investigators from Memorial Sloan-Kettering Cancer Center (MSKCC) have used new techniques in the laboratory that allowed them for the first time to derive unlimited numbers of purified mesenchymal precursor cells from human embryonic stem cells (HESCs). Mesenchymal precursor cells are capable of giving rise to fat, cartilage, bone, and skeletal muscle cells, and may potentially be used for regenerative stem cell therapy in bone, cartilage, or muscle replacement.

The new study, demonstrating the specialized techniques for isolating mesenchymal precursors and generating, purifying, and differentiating those cells in culture, is published online and freely available in the journal PLoS Medicine (Public Library of Science).

Researchers took two lines of completely undifferentiated HESCs and by culturing them in the presence of mouse cells, stimulated them to turn into mesenchymal cells. They then treated these cells with compounds to make them change into specialized bone, cartilage, fat, and muscle cells. According to the study, researchers were able to confirm that these cells were all human cells and that there was no evidence that the cells became cancerous.

Mesenchymal precursors derived from HESCs are different from adult mesenchymal cells because they can efficiently differentiate into skeletal muscle (adult mesenchymal cells do not) in addition to fat, cartilage, and bone. Limited numbers of mesenchymal stem cells have been isolated from adult bone marrow and connective tissues, but harvesting these cells from any of these sources requires invasive procedures and the availability of a suitable donor. The capacity of these cells for long-term proliferation is also poor. In contrast, HESCs could provide an unlimited number of specialized cells.

According to Lorenz Studer, MD, PhD, Head of the Stem Cell and Tumor Biology Laboratory at MSKCC and senior author of the PLoS Medicine study, the high purity, unlimited availability, and multi-potentiality of mesenchymal precursors derived from HESCs will provide the basis for preclinical mouse studies to assess the safety of these cells. The investigators have already taken the next step in this research and are testing the therapeutic potential of embryonic stem cell-derived muscle cells in animal models of muscle disorders.