It is imperative that any application of stem cells in people is driven by firm scientific evidence. Any activity without such evidence must be strictly condoned and prevented, says Sanjeev Gupta, who holds the Eleazar and Feige Reicher Chair in Translational Medicine, Albert Einstein College of Medicine, US.
Dr. Gupta is one of the authorities on stem cell research, with particular interest in regeneration of the liver through stem cells. In Chennai recently, on the invitation of the Institute of Gastrointestinal Surgery, Government Stanley Hospital, he said it was particularly important that false hope was not generated through inappropriate, premature or unwise use of stem cells.
“These areas of activity, it seems to me, have not been appropriately regulated, permitting many unscrupulous individuals to take steps for financial gain, not for benefitting people,” he stressed.
Appropriate measures must be taken at multiple levels – at the medical and political establishment levels to ensure that this is controlled. Only with the right type of scientific evidence and validation, will treatments be effective over the long run.
“Right now,” Dr. Gupta explained, “there is an enormous amount of good and bad information about stem cells. On the one hand, people believe that stem cells will cure everything, and on the other hand, that they have failed to make an impact so far.” The truth, is somewhere in between, he contended.
There is increasing information now, on stem cells. The major emphasis is on identifying the biological components of stem cells and how they could be harnessed for repairing organs. There is also great interest in liver-directed stem cell therapy, as this has the potential to impact on the condition of other organs as well. That makes the liver the most attractive, single target for stem cell therapy.
Serious efforts have been made towards understanding how a liver fails, and treating the liver with transplantation of healthy stem cells, to see if they can correct the disorders. Trying to make liver cells from stem cells is one way. Simultaneously, there has been a lot of interest in using cells from other parts of the body, such as bone marrow or the peripheral vascular system, with the consideration that those cells will convert themselves to the damaged organ, and start the process of repair.
“There is as yet no compelling scientific evidence that blood-derived cells can replace tissue cells elsewhere – such as the liver,” he said. However, there is definitely the possibility that these cells can be extracted, as also cells from the skin, intestinal tract, or eye, and converted to stem cells.
“At the moment, it requires manipulation, insertion of multiple genes that could cause cancers. There is a lot of work to do in the field,” Dr. Gupta explained.
There is another component of stem cells that has not received as much attention in the public mind, he said. This is the activation of one's own endogenous stem cells, or of one's own resident stem cells in every organ. “If there is damage to the organ, why can't we activate our own residual stem cells so that they can repair through appropriate signals?” he asks.
“The million dollar question is why those cells are not getting activated. Much work is being done to understand the biology of signals and cues that may coax these cells to become active again, and begin regeneration of various tissues in the body. However, this work is in its infancy,” Dr. Gupta added.
Once we understand these mechanisms, we may be able to develop new drugs that can activate these stem cells and we may not even need to transplant anything, he said.
Further important advances will come in our understanding of immunological mechanisms by which rejection of transplanted cells derived from stem cells can be prevented, and identification of the early stage where stem cells begin to get depleted, to fashion treatments that will prevent the onset of certain diseases.
