Cancer treatment: where DNA, stem cells and cell immortality meet – News – The University of Sydney

Associate Professor Tony Cesare with members of his lab team at CMRI. Follow the lab on Twitter @TheCesareLab

The immortals we all carry are stem cells that are like universal patches that convert into whatever cells are needed at that moment skin cells, bone, hair, gut. Stem cells must be ever ready, so their telomeres are kept permanently long by an enzyme called telomerase. Stem cells are the only cells in the body that get this telomerase attention.

That means, once a stem cell becomes a specific type of cell, it no longer has a way to keep its telomeres long, says Cesare. From then on, the telomeres shorten every time it divides.

The internet snake oil sellers have grabbed onto the telomerase enzyme as a possible doorway to health and extended longevity, recommending it as a supplement to keep telomeres long, but as one of the worlds most knowledgeable people on the subject, Cesare advises against.

By giving a cell telomerase, and artificially extending its life, you're interfering in how telomeres prevent damaged cells multiplying and how they prevent tumours from happening, he says. Use telomerase in this way, and I believe the result could be cancer. To underscore the point, consider this: there is one other group of cells unexpectedly kept immortal by telomerase: cancer cells.

Cancer is a wily adversary: evading the immune system; hijacking the bodys nutrition sources to feed itself; riding the bloodstream to other parts of the body. And yes, cancer tricks telomerase into elongating telomeres, thereby allowing its cells to replicate ad infinitum.

We don't study specifics like pancreatic cancer or breast cancer, says Cesare. We're interested in what damage occurs with the DNA that allows a cell to become cancerous, to become immortal.

The crossroads of telomerase, cancer and stem cells is proving to be a rich source of new insights, not just about cancer and longevity, but also for the burgeoning field of regenerative medicine; the idea being that if stem cells can transform into almost any other cell in the body, could they be used to generate body tissues for transplantation?

Much of Cesares research is now focused on how telomeres control the delicate balance between allowing and preventing cell division.

It is a strange contradiction of short telomeres that while they are associated with the conditions of aging, they are also critically important in preventing cancer. Cesare was the first to understand a critical step in this cancer prevention mechanism and how it relates to cell division.

When actual DNA is damaged (as opposed to the telomeres), a signal stops cell division from happening until the DNA is repaired. Then cell division starts again. Cesare found that short telomeres can turn on the damage signal to stop cell division, while also preventing repair from happening. In effect, permanently retiring the cell.

Allowing that cells with short telomeres are reaching the end of their usefulness, and may indeed be making poor copies of themselves, preventing these cells from multiplying reduces the possibility of cancers developing.

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Cancer treatment: where DNA, stem cells and cell immortality meet - News - The University of Sydney