Yesterday, together with his colleagues, Mark Davis from the California Institute of Technology in Pasadena published their findings of a study in Nature magazine on the method that they developed to deliver short sequences of RNA to human melanomas, interrupting the replication process of the cancerous cells.

The technique of using these short RNA sequences to turn off, or silence, specific genes was coined RNA interference (RNAi) by Craig C. Mello and Andrew Fire, 2 American biologists who were awarded the Nobel Prize in Physiology or Medicine in 2006 for their research into the phenomenon, which they first reported in a paper in Nature in 1998. However, since then there has not been much success in getting this process to the clinic, due in part with difficulties in the delivery of the sequences to the intended target. The method developed by the team from Caltech uses nanoparticles to help solve this problem. Using two polymers plus a protein that binds to both receptors that are on the surface of cancer cells and siRNA (small-interfering RNA), the researchers are able to inhibit the expression of a key gene, RRM2, preventing it from being translated into protein, and thus halting it from multiplying.

The particles themselves used in this process are about 70 nanometers in diameter. They are introduced into a patients blood stream, which they travel through until they encounter the tumors. They then binds to the cells of the tumor, and get absorbed. The nanoparticles then fall apart, unbinding the polymers from the siRNA, which then sticks to the cell’s messenger RNA (mRNA), halting the translation process. The polymers then pass out of the body through the urine.

While further testing is needed to make sure that therapies using this method are safe, Davis has hopes that the treatments will have no major side effects. “My hope is to make tumours melt away while maintaining a high quality of life for the patients,” he says. “We’re moving another step closer to being able to do that now.”

Further reading Cancer genes silenced in humans.

©2010 Amazing New Science Discoveries. All Rights Reserved.

In a proposal reminiscent of Noah’s Ark, scientists plan to collect DNA sequences for 10,000 vertebrate species, approximately one for every vertebrate genus. The Genome 10K Project, or “genome zoo”, will be analyzed to reveal evolutionary changes that took place, leading to the species here today.

Sixty-eight scientists, called the Genome 10K Community of Scientists (G10KCOS), will gather specimens of thousands of animals from zoos, museums, and other collections worldwide. Once collected, they will begin sequencing the genome of each.

David Haussler, professor of biomolecular engineering at UC Santa Cruz and one of the lead project scientists, said,

For the first time, we have a chance to really see evolution in action, caught in the act of changing whole genomes. This is possible because the technology to sequence DNA is thousands of times more powerful now than it was just a decade ago, and is poised to get even more powerful very soon. Differences in the DNA that makes up the genomes of the animals we find today hold the key to the great biological events of the past, such as the development of the four-chambered heart and the magnificent architecture of wings, fins and arms, each adapted to its special purpose.

This “Noah’s Ark of DNA” can lead to discoveries not only of how evolution occured in our past, but can help scientists predict how species will respond to future events such as climate change, disease, and pollution.

For more into this research, as well as how you can be involved as an active participant, check out the Genome 10K Project site.

©2010 Amazing New Science Discoveries. All Rights Reserved.

The quest for the ability to grow back organs and limbs, the “holy grail” of regenerative medicine, took a giant leap forward recently. Physorg.com reported Tuesday that researchers at the Salk Institute for Biological Studies recently identified an essential cellular pathway that unlocks certain gene expression patterns that are last seen in humans only during embryonic development. The source of this amazing new discovery? The zebrafish, a cousin to the minnow that is often found in aquariums.

Zebrafish

Izpisúa Belmonte, a professor in the Gene Expression Laboratory, was quoted as saying, “Our experiments show that normal development and limb regeneration are controlled by similar mechanisms. This finding will help us to ask more specific questions about mammalian limb regeneration: Are the same genes involved when we amputate a mammalian limb? If not, what would happen if we turned them on? And if we can affect these methylation marks in an amputated limb, what effect would that have?”

The institute’s findings on the subject are to be published in an upcoming issue of “Proceedings of the National Academy of Sciences“, a biweekly multidisciplinary journal that covers the biological, physical, and social sciences.

©2010 Amazing New Science Discoveries. All Rights Reserved.