The Centre for Stem Cell Research at Christian Medical College has succeeded in reprogramming cells drawn from adult mice and making them function like stem cells found in the human embryo. It has opened a new chapter in stem cell therapy in the country, as the technology can now be applied to generate similar stem cells from adult human cells too. These can be used to study genetic disorders relating to blood, muscle, brain and even diseases like diabetes.
The use of embryos to draw stem cells has been the subject of a controversy, and the latest discovery may mean that embryos need not necessarily be used in the process. ”This is an important milestone for India in stem cell research and signifies a paradigm shift in the way diseases can be treated. We will now begin work on human cells to generate disease-specific iPS cells to study hereditary diseases,” Dr Alok Srivastava, who heads the research centre, said. ”For India, this means once we are able to take this on to human cells also; we will not have to rely on external help for generating models for studying and treating human diseases. With regard to clinical significance, as anywhere else in the world, we need to be very careful not to give an impression to people that this is going into human treatment anytime soon. It could be years before that happens and it will be only after the safety of use of such cells is clearly established,” he said.
In February, the research centre, supported by the department of biotechnology, ministry of science and technology and CMC, was successful in generating in mice these ”induced pluripotent stem (iPS) cells” which are similar to embryonic stem cells. Researchers will soon move on to generating similar cells from normal and diseased human cells.
The centre looks primarily at translational research – research that has potential for clinical applications. Embryonic stem cells have great capacity for self-renewal and are used in regenerative medicine and tissue replacement. The induced pluripotent stem (iPS) cells generated at the research centre may have the same potential, researchers say. India is the fifth country, after Japan, US, China and Britain, to achieve these results. The iPS technology is relatively new and acknowledged worldwide as the ”ultimate manufacturing process”. Scientists can now use the human skin or other cells like an assembly line to roll off cells that have the ability to adapt themselves to any tissue in the body that requires healing or replenishment.
Stem cells are cells found in most, if not all, multi-cellular organisms. They are characterized by the ability to renew themselves through mitotic cell division and differentiating into a diverse range of specialized cell types. Research in the stem cell field grew out of findings by Canadian scientists Ernest A. McCulloch and James E. Till in the 1960s.The two broad types of mammalian stem cells are: embryonic stem cells that are isolated from the inner cell mass of blastocysts, and adult stem cells that are found in adult tissues. In a developing embryo, stem cells can differentiate into all of the specialized embryonic tissues. In adult organisms, stem cells and progenitor cells act as a repair system for the body, replenishing specialized cells, but also maintain the normal turnover of regenerative organs, such as blood, skin or intestinal tissues.
Induced pluripotent stem cells commonly abbreviated as iPS cells or iPSCs, are a type of pluripotent stem cell artificially derived from a non-pluripotent cell, typically an adult somatic cell, by inducing a “forced” expression of certain genes.
Induced Pluripotent Stem Cells are believed to be identical to natural pluripotent stem cells, such as embryonic stem cells in many respects, such as the expression of certain stem cell genes and proteins, chromatin methylation patterns, doubling time, embryoid body formation, teratoma formation, viable chimera formation, and potency and differentiability, but the full extent of their relation to natural pluripotent stem cells is still being assessed.
IPSCs were first produced in 2006 from mouse cells and in 2007 from human cells. This has been cited as an important advancement in stem cell research, as it may allow researchers to obtain pluripotent stem cells, which are important in research and potentially have therapeutic uses, without the controversial use of embryos.