Why Gene-Therapy Is Not Likely To Aid Cystic Fibrosis Sufferers Anytime Soon

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In my last post, I contended that the best way to fight Cystic Fibrosis and other genetic diseases is to keep couples likely to pass on the disease from procreating.

The next best and most fundamental way to correct the Cystic Fibrosis problem (if, tragically, we continue to treat the disease as first-and-foremost a post-conception problem) would be to fix the gene-malfunction occurring in sufferer. However, once a fetus is under construction, it is too late, so to speak, to catch the DNA train. A person cannot change his genetic make-up. Well… basically…

Now, what we CAN do (though we’re no experts at this yet) is to change which portions of DNA are activated and when. One way to do this is through the manipulation of so-called Epigenetic Factors.

One of the biggest epigenetically influenced events of the life-cycle is the onset of puberty– which begins earlier or later based on a variety of factors– all largely to do with body-stresses; for instance, a healthy, well-fed young body will, all else being equal, begin puberty earlier, whereas a body that is malnourished or otherwise under certain stresses may delay the onset of puberty. (This by the way is one reason that families in the West have noticed an earlier onset of puberty over the last several generations).

The epigenetic strategy can be thought of as the attempt to manipulate the environment of the human body so that its genes produce a more timely or better class of products.

Perhaps it is within the realm of possibility that one day we will be able to affect Epigenetic Factors of individuals according to our whims– turning genes on and off howsoever we desire. Unfortunately, the Cystic Fibrosis (CF) problem is one of improper cellular membrane construction; and we simply don’t have the knowledge and skillset to reconfigure cell membranes via the turning-on and turning-off of genes at the precisely correct instant for each alteration desired.

A similar approach, but on a level slightly more macro (and, not unrelatedly, a little more within the realm of possibility) is the idea that we could manipulate the intra-cell assemblage of parts at a grosser level than DNA or genes–  at, say, the level of enzymes and signaling chemicals within the cell. The hope is that we would have the knowledge and ability to smooth-out whatever bumps are occurring in the cell’s construction and self-maintenance processes, and thereby correct the misconstruction of the membrane.

One idea along these lines which sounds — at first-hearing– like a promising avenue is that of packing a virus with cell-fixing tools, and then infecting the patient with this virus in the hopes that the tampered-with virus will then force its way into the body’s cells (as viruses are prone to do), where it will release the healing contents of its package. This approach, however, is– at least for the foreseeable future– mere fantasy…

To begin with, we need the virus to infect ONLY certain cell types– in the case of CF, the Epithelial Cells. This is actually somewhat feasible– though risky– because viruses often already come prone to attack specific organs of the body. But there are catches…

We are talking about millions and millions of Epithelial Cells necessitating correction. That level of viral infection is apt to trigger the body’s Immune System response– which, depending on the level of alarm-and-attack generated, could have tragic consequences for the patient.

Furthermore, all these Epithelial Cells are constantly dying-off and being replaced by new cells designed from the same faulty DNA plan at the heart of the problem. Even if we could safely and without unforeseen consequences re-jigger several million cells in the body– we’d need to do it again the next week, and the next week, and so on…

For another thing, we do not yet even know exactly how to go about fixing CF-afflicted cells– even if the virus-delivery system worked perfectly and there were no Immune System or other side-effects.

Nor are we even close to being able to keep viruses from mutating and performing activities– terrible-horrible, life-ending activities– outside their job description. A prettied-up virus is a tiger on a paper leash.

And that’s not all… Although the vast majority of CF-gene muck-ups appear to stem from one specific error in the construction of Epithelial Cells– there are actually over 800 different membrane-making errors which produce the symptoms that come under the umbrella term of “Cystic Fibrosis.” That’s a lot of microscopic problems to solve, each with its own tool-it and delivery package to be applied.


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