I haven't posted much lately. It's because I'm obsessively reading Rebecca Skloot's new book
The Immortal Life of Henrietta Lacks, and spending all my free time this week curled up with it (my husband is jealous.) Crazy wild events keep unfolding, and I can't put it down.
I'm about 3/4 of the way through, just past a chapter that wonders why
the cells derived from Henrietta's cervical cancer won't die. What makes them 'immortal', thriving in research labs for decades? The answer might be in their
telomeres, caps on the end of chromosomes inside cells, said cancer researchers in the 70's. Today, I came across a newly published study about telomeres, covered by fellow science bloggers. Proves cell growth/death is still a very relevant area of study.
For decades, cancer researchers have known that telomeres shorten as we age. When a telomere finally disappears, the cell's time has run out and it dies. Cancer cells have telomerase, an enzyme that keeps telomeres from falling apart. Thus, they can be nearly immortal, like Henrietta Lack's cancer cells (dubbed
HeLa cells.)
In
the new study, researchers bred mice without telomerase (the mice aged prematurely) and then reintroduced telomerase into their body by turning on a telomerase gene (they aging process slowed.) My understanding of the study is that the authors don't claim they can completely reverse or even stop the cell aging (and thus animal aging) process, just stop the degeneration of telomeres so that the mice don't age any more than they normally would. Other researchers have found that stressed-out women also
have shorter telomeres, suggesting that stress really does age you.
So, are monthly baths in the fountain of telomerase in our future? I don't know. It's a long way from transforming a cell or tissue to halting the aging process of an entire organism. Henrietta Lack's children used to think that parts of their mother's body was actually living somewhere--copies of her arms were shaking hands with researchers in Iowa while copies of her legs were kicking around in Boise. Truth is--it's just her cancer cells that are still living decades later in laboratories throughout the world. Researchers
have grown whole slabs of meat (fish and pig tissue) in the laboratory, using techniques that turn on the telomerase. But, let's get real--we're still not anywhere near a cure for aging. It's still kind-of a scary thought anyway.
[The Immortal Life of Henrietta Lacks is a must-read.]
Jaskelioff M, Muller FL, Paik JH, Thomas E, Jiang S, Adams AC, Sahin E, Kost-Alimova M, Protopopov A, Cadiñanos J, Horner JW, Maratos-Flier E, & Depinho RA (2010). Telomerase reactivation reverses tissue degeneration in aged telomerase-deficient mice. Nature PMID: 21113150
