[michaelhoffman]

Without telomerase, the telomeres will degrade each cell division until the Hayflick limit, where they die. So without telomerase there is a built-in limitation on the number times a cancer cell can reproduce before it dies.

It's quite simple and doesn't require any interaction with other cellular machinery.

[jwco]

Thanks, but it's not clear to me that cells die without telomeres or at this Hayflick limit. http://en.wikipedia.org/wiki/Hayflick_limit says they enter senescence. They stop dividing. This seems different than cell death.

That is interesting to me too though. I don't know why cells should stop dividing without telomeres, or with telomeres below a critical length. That suggests to me there is interaction with other cellular machinery at this onset of senescence.