MICRO WRITERS

July 2008: Santa Cruz, University of California

A surprising type of gene regulation found in mammals under the influence of RIBOZYME

A ribozyme, as the name implies, is an RNA molecule that can catalyze a chemical reaction. Although, RNA is mostly known to play a role in the encoding of genetic info, leaving the catalysis of biological reactions up to enzymes made out of protein. Now, scientists are discovering that RNA might be taking part in both.

The hammerhead ribozyme, previously known to be associated with viroids “plant viruses”, has been found in mice, rats, horses, and other mammals, embedded within certain genes & controlling their expression. Example of such genes are those involved in the body’s immune response & metabolism of bone. In these genes, the mRNA contains sequences that form a hammerhead ribozyme.

The hammerhead ribozyme is a self-cleaving molecule that cuts itself in two. That way, the protein translation is prevented & therefore, no gene expression takes place. To turn the process back on, the self-cleaving action is stopped. Exactly what shuts off the ribozyme action is not known, but assumed to be there.

Two interesting points come up now:

1. The hammerhead ribozyme sequences first appeared in the genomes of rat & mice and then turned up in other mammals but was not found in the corresponding human genes which suggests that a different mechanism DOES exist regulating those genes in humans.

2. The genes, being regulated by a hammerhead ribozyme, are involved in the immune response & in bone metabolism. Such finding can be targeted by the pharmaceutical industry to combat certain autoimmune diseases & bone disorders, which offers potential for better & safter healthcare treatment in the future.

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May 2008

Gene Therapy: Seeing the future with new eyes

For the first time, doctors have used gene therapy to restore some vision in children with a congenital vision problem called Leber Congenital Amaurosis or “LCA” caused by a faulty gene (RPE65) 

The procedure involved the injection of a solution containing the normal gene, carried on an adenovirus vector, into the back of the retina of the affected eye.

In Britain, three patients have been treated with this experimental therapy. One has significantly improved & has been video-taped prior to the treatment & then six months later, traveling through a maze. Video HERE

The other two patients, aged 17 and 23, did not report any improvement, but did not suffer any side effects either.

Similarly, a US research team experimented on three patients, one aged 19 and two aged 26, and are reported to have improved vision as measured by standard eye tests, however, one developed a hole in the retina, thought to be due to the surgery itself.

This is a very significant milestone especially because researchers have been dealing with patients in the late stages of the disease & more hope is yet to come in those with the less-advanced form.

This is only the second time gene therapy has been proved successful in humans, after trials showed it was effective in the rare inherited disorder SCID (Severe Combined Immune Deficiency)

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