Weeding out the bad cells from the good in stem cell therapies

These iPS cells can form any cell in the body (image by Kathrin Plath, UCLA)

The good: Both embryonic stem cells and adult cells reprogrammed to an embryonic-like state (iPS cells) can form all types of tissues in the body. Scientists around the world are pushing those cells to form skin, tissues of the eye, insulin-producing cells and various types of nerve cells as potential disease therapies.

The bad: A small number of cells don't leave their embryonic state to form the desired tissue. Some sit there in the lab dish, hanging on to their infinite possibilities. The problem is that if those cells get injected into a patient along with their mature counterparts, they could end up, for example, in the brain, where they might up and decide to form the wrong kind of tissue. Bone, say, or liver. Or cancer.

The hopeful: Our grantees Carla Koehler and Michael Teitell at UCLA have discovered a way to induce those lurking embryonic cells to commit cellular suicide while leaving the more mature cells unscathed. Shaun Mason wrote about the work for UCLA:

Why this happens is still unclear, but the researchers said that this ability to separate the two cell populations could potentially reduce the risk of teratomas [a type of tumor] and other problems in regenerative medicine treatment strategies.

Their technique could make cell therapies safer by weeding out any potentially harmful cells from a pool of therapeutic ones. 

The work was published online April 15 in the journal Developmental Cell.

CIRM Funding: (Michael Teitell & Carla Koehler, RS1-00313 &  RB1-01397; Kiyoko Setoguchi TG2-01169)

A.A.