Slashdot Mirror
Tumor-suppressing Gene Contributes to Aging
Van Cutter Romney writes "Scientists have discovered a tumor suppressing gene which also leads to aging in stem cells. The gene also known as p16INK4a when removed from 'knockout' mice resulted in older mice having organs as healthy as younger ones. However they didn't live any longer than normal mice. The new study was confirmed by three independent researchers from Harvard, UNC Chapel Hill and University of Michigan."
"I don't think aging is a random process - it's a program, an anti-cancer program,"
Cancer, then, is an anti-aging program.
The article basically states that when they turned off the flow of ink-4, embyyonic stem cells were free to divide without check. The mice without the ability to produce ink-4 developed cancer within a year and died. This behavior cannot be reliably reproduced in aged stem cells, and ink-4 production naturally increases exponentially with age.
The main news I see here is either a possible avenue for cancer research, or a good supporting argument to lift bans on exploiting new strains of embryonic stem cells (over adult stem cells). This does not represent a specific breakthrough, but yet another amazing revelation of stem cell capabilites has come to light.
I support the ban on cloning, I disagree with the ban on new stem cells, I am relatively opposed to mass abortion, but banning it would be stupid. I think this story's new information supports these views.
FairTax baby!
No, it is different. In the story a year ago, a korean group found that if you suppress telomerase in cancer cells--an enzyme that makes cells 'immortal' by continually adding repeats of bases on to the ends of chromosomes--the cells die. the summary on the slashdot page is not exactly correct--telomerase is not an enzyme specific to cancer cells. In this present work, it is a gene that, in a way, computes a differential equation--weighing the importance of replacing cells using stem cells from its cache against the risk that the replication of cells will result in a cancerous cell. "To offset the increasing risk of cancer as a person ages, the gene gradually reduces the ability of stem cells to proliferate." it is a fundamentally different story and is interesting.
The first thing that needs to fail is the proofreading enzymes, so that a gene or two are damaged without being repaired.
Then the "self destruct" needs to fail to activate in a cell, The self destruct is almost always armed and ready to go, unless it gets knocked out by a "lucky" mutation.
Even if the self destruct fails, the cell sensing needs to fail in order to grow beyond a few cells. Then the telemorase halting needs to fail in order for the cancer to reach something larger than a mole.
The immune system is a last resort, and not a very good one in comparison.
Storm
One key mistake in the parent's summary: Ink-4 limits the ability of adult stem cells to divide. The article suggests a theory that because damaged adult stem cells are prevented from dividing by Ink-4, unchecked tumor growth (cancer) is averted later in life.
How this supports embryonic stem cell research is: we now have evidence that adult stem cells will not be effective when used as treatment because they will be naturally suppressed. Thus to get stem cells that will divide and provide therapy, we must use embryonic cells.
---k--
</stupid>