U.S. scientists reported on Sunday that they have found a way to convert an ordinary skin cell into valued embryonic-like stem cells, with the potential to grow batches of cells that can be directed to form any kind of tissue. (Rueters Photo)

    BEIJING, Dec. 24 (Xinhuanet) -- U.S. scientists reported on Sunday that they have found a way to convert an ordinary skin cell into valued embryonic-like stem cells, with the potential to grow batches of cells that can be directed to form any kind of tissue.

    The study, carried out by a team led by Dr. George Daley of Harvard Medical School and Children's Hospital Boston, Massachusetts, was published in the journal Nature.

    Daley said his team have been able to use the same four genes that Japanese scientists used to derive the so-called induced pluripotent stem (or iPS) cell from fetal lung and skin cells, from neo-natal skin cells as well as from skin samples taken from a healthy human volunteer.

    In November, Shinya Yamanaka of Kyoto University and colleagues announced they had reprogrammed human skin cells to have the multiple potency of stem cells culled from human embryos.

    Yamanaka's team used a retrovirus to deliver four genes into skin cells taken from a mouse and an adult human, this turned the clock back so that these cells lost their differentiated profile and became iPS cells.

    However, the work of Daley's team marks a step forward to "patient-specific" stem cells -- in other words, transplanted stem cells that carry the same genetic code as the patient and thus cannot be rejected as alien by the body's immune system.

    The U.S. scientists said they could generate iPS without a cancer gene called c-Myc that has been implicated in tumors in many lab mice in earlier experiments.

    But Daley and colleagues warned that there is still a long way to go until they can successfully apply stem cell therapy to real life patients.

    "Clinical success with human iPS cells must await the development of methods that avoid potentially harmful genetic modification," researchers said in the Nature.

    (Agencies)