Hidden promise of vitamins A, C revealed

A new study has found how vitamins A and C can enhance success in the challenging process of converting adult cells into stem cells. Photo / Supplied

The powerful combination of two vitamins could be a hidden key to curing human diseases through regenerative medicine.

A new study, co-authored by Otago University scientist Dr Tim Hore, has found how vitamins A and C can enhance success in the challenging process of converting adult cells into stem cells.

The two vitamins were discovered to complement each other in erasing "memory" associated with DNA - an important effect for improving technologies geared towards regenerative medicine and stem cell therapy.

In the study, just published in the major journal Proceedings of the National Academy of Sciences, the researchers showed how ordinary adult cells, such as those in the skin or blood, could be artificially coerced in a culture dish to resemble embryos only a few days old.

Hore, of Otago's Department of Anatomy, said that since the 2006 discovery that the remarkable "re-programming" process was possible, there had been much interest in using induced embryonic stem cells to cure human disease.

"However, hampering these efforts is the reality that adult cells are resistant to changes in their identity, partly because of chemical alterations to their DNA."

These alterations, known as "DNA methylation", were acquired during development and provide a form of cellular memory that helped cells faithfully maintain a specialised function.

Removal of this memory was critical to create a developmentally potent stem cell, or to change one kind of adult cell to another.

With collaborators at the UK's Babraham Institute and in Stuttgart, Germany, Hore determined that adding vitamins A and C to culture dishes removed DNA methylation from embryonic stem cells.

When applied to cells during the reprogramming process, those with the desired "naive" embryonic characteristics were created in much greater numbers.

The mechanism by which this occurred was also detailed in the study.

"We found that both vitamins affect the same family of enzymes which actively remove DNA methylation; it turns out that Vitamin A increases the number of these enzymes within the cell, and Vitamin C enhances their activity," he said.

Beyond regenerative medicine, this work may also have implications for other areas of biomedical importance.

Loss of DNA methylation and cellular memory are a hallmark of certain cancers, so a better understanding of how this process occurs could prove significant.

"Along with other Otago research groups, my lab is beginning to explore how the vitamin-induced effects we have uncovered in this study might impact on the loss of DNA methylation in certain cancers."