Is there really such a thing as a Cancer Stem Cell (CSC) ?
The traditional view of carcinogenesis was that any run-of-the-mill cell could become cancerous by accomplishing three things:
- The deactivation of a tumor suppressor gene,
- A proto-oncogene becoming an oncogene,
- Reversion to a more primitive, stem-like state allowing them to activate telomerase, the enzyme that allows the ends of chromosomes (telomeres) to lengthen and make the cell immortal.
This theory is analogous to a long-time worker bee transforming itself into a Queen Bee without all the special diet and preparation that is normally required.
Burning the candle at both ends
Once upon a time, scientists thought that all cells in a dish could grow forever, like cancers. But experiments showed that differentiated (aka non-stem) cells only divide about 50 times before the colony dies out. The destiny of these differentiated cells is a product of two fundamental rules: non-stem cells don’t activate telomerase and the replication of non-circular DNA always results in some shortening of DNA at the telomeres. This aging your chromosomes is like burning a candle at both ends and is known as REPLICATIVE SENESCENCE.
When the telomeres inevitably become critically short on any of the 92 chromosomal tips in every cell, the informational DNA is exposed and will be damaged. Telomerase is your stem cells’ way of manufacturing new telomere DNA to keep your chromosomes capped and protected.
The Cancer Stem Cell model
The new paradigm is that cancers, like the cells in your healthy organs, are maintained by very rare Cancer Stem Cells (CSC’s). Using the beehive metaphor, if you get the carcinogenic mutations in the Queen Bee (stem cell), the resulting new CSC is already an immortalized, telomerase-active cell. That may help explain why highly toxic radiation and chemotherapy sometimes kills off the “worker bees,” but since the robust Queen survives, she can recreate a whole new colony
Whether none, some, or all of clinical malignancies have CSC’s is a matter of ongoing investigation and controversy. What seems clear is that by telomerase activation, TA-65 safely adds more “wick” to the candles that are your telomeres. By delaying the damage to our cellular DNA, we delay the ravages of time. At the cellular level, we call those ravages REPLICATIVE SENESCENCE. At the human level, we call it getting old.
For more information about CSC’s go to: http://www.rechargebiomedical.com/cancer.html