Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Researchers achieve RNA interference, in a lighter package: Pared-down nucleic acid nanoparticle poses less risk of side effects, offers better targeting.

Researchers successfully used this nanoparticle, made from several strands of DNA and RNA, to turn off a gene in tumor cells.
Image: Hyukjin Lee and Ung Hee Lee
Researchers successfully used this nanoparticle, made from several strands of DNA and RNA, to turn off a gene in tumor cells.

Image: Hyukjin Lee and Ung Hee Lee

Abstract:
Using a technique known as "nucleic acid origami," chemical engineers have built tiny particles made out of DNA and RNA that can deliver snippets of RNA directly to tumors, turning off genes expressed in cancer cells.

Researchers achieve RNA interference, in a lighter package: Pared-down nucleic acid nanoparticle poses less risk of side effects, offers better targeting.

Cambridge, MA | Posted on June 4th, 2012

To achieve this type of gene shutdown, known as RNA interference, many researchers have tried — with some success — to deliver RNA with particles made from polymers or lipids. However, those materials can pose safety risks and are difficult to target, says Daniel Anderson, an associate professor of health sciences and technology and chemical engineering, and a member of the David H. Koch Institute for Integrative Cancer Research at MIT.

The new particles, developed by researchers at MIT, Alnylam Pharmaceuticals and Harvard Medical School, appear to overcome those challenges, Anderson says. Because the particles are made of DNA and RNA, they are biodegradable and pose no threat to the body. They can also be tagged with molecules of folate (vitamin B9) to target the abundance of folate receptors found on some tumors, including those associated with ovarian cancer — one of the deadliest, hardest-to-treat cancers.

Anderson is senior author of a paper on the particles appearing in the June 3 issue of Nature Nanotechnology. Lead author of the paper is former MIT postdoc Hyukjin Lee, now an assistant professor at Ewha Womans University in Seoul, South Korea.

Genetic disruption

RNA interference (RNAi), a natural phenomenon that cells use to control their gene expression, has intrigued researchers since its discovery in 1998. Genetic information is normally carried from DNA in the nucleus to ribosomes, cellular structures where proteins are made. Short interfering RNA (siRNA) disrupts this process by binding to the messenger RNA molecules that carry DNA's instructions, destroying them before they reach the ribosome.

siRNA-delivering nanoparticles made of lipids, which Anderson's lab and Alnylam are also developing, have shown some success in turning off cancer genes in animal studies, and clinical trials are now underway in patients with liver cancer. Nanoparticles tend to accumulate in the liver, spleen and lungs, so liver cancer is a natural target — but it has been difficult to target such particles to tumors in other organs.

"When you think of metastatic cancer, you don't want to just stop in the liver," Anderson says. "You also want to get to more diverse sites."

Another obstacle to fulfilling the promise of RNAi has been finding ways to deliver the short strands of RNA without harming healthy tissues in the body. To avoid those possible side effects, Anderson and his colleagues decided to try delivering RNA in a simple package made of DNA. Using nucleic acid origami — which allows researchers to construct 3-D shapes from short segments of DNA — they fused six strands of DNA to create a tetrahedron (a six-edged, four-faced pyramid). A single RNA strand was then affixed to each edge of the tetrahedron.

"What's particularly exciting about nucleic acid origami is the fact that you can make molecularly identical particles and define the location of every single atom," Anderson says.

To target the particles to tumor cells, the researchers attached three folate molecules to each tetrahedron. Short protein fragments could also be used to target the particles to a variety of tumors.

Using nucleic acid origami, the researchers have much more control over the composition of the particles, making it easier to create identical particles that all seek the right target.

Circulate and accumulate

In studies of mice implanted with human tumors, the researchers found that once injected, the nucleic acid nanoparticles circulated in the bloodstream with a half-life of 24 minutes — long enough to reach their targets. The DNA tetrahedron appears to protect the RNA from rapid absorption by the kidneys and excretion, which usually happens with RNA administered on its own, Anderson says.

"If you take a short interfering RNA and inject it into the bloodstream, it is typically gone in six minutes. If you make a bigger nanoparticle using origami methods, it increases its ability to avoid excretion through the kidneys, thereby increasing its time circulating in the blood" he says.

The researchers also showed that the nucleic acid nanoparticles accumulated at the tumor sites. The RNA delivered by the particles was designed to target a gene for luciferase, which had been added to the tumor cells to make them glow. They found that in treated mice, luciferase activity dropped by more than half.

The team is now designing nanoparticles to target genes that promote tumor growth, and is also working on shutting off genes involved in other genetic diseases.

The research was funded by the National Institutes of Health, the Center for Cancer Nanotechnology Excellence, Alnylam Pharmaceuticals and the National Research Foundation of Korea.

####

For more information, please click here

Contacts:
Sarah McDonnell
MIT News Office

T: 617-253-8923

Copyright © MIT

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

New Hopes for Treatment of Intestine Cancer by Edible Nanodrug March 2nd, 2015

Imec, Holst Centre and Renesas Present World’s Lowest Power 2.4GHz Radio Chip for Bluetooth Low Energy March 1st, 2015

Imec, Murata, and Huawei Introduce Breakthrough Solution for TX-to-RX Isolation in Reconfigurable, Multiband Front-End Modules for Mobile Phones: Electrical-Balance Duplexers Pave the Way to Integrated Solution for TX-to-RX Isolation March 1st, 2015

Imec Demonstrates Compact Wavelength-Division Multiplexing CMOS Silicon Photonics Transceiver March 1st, 2015

Govt.-Legislation/Regulation/Funding/Policy

First detailed microscopy evidence of bacteria at the lower size limit of life: Berkeley Lab research provides comprehensive description of ultra-small bacteria February 28th, 2015

Warming up the world of superconductors: Clusters of aluminum metal atoms become superconductive at surprisingly high temperatures February 25th, 2015

SUNY Poly CNSE Researchers and Corporate Partners to Present Forty Papers at Globally Recognized Lithography Conference: SUNY Poly CNSE Research Group Awarded Both ‘Best Research Paper’ and ‘Best Research Poster’ at SPIE Advanced Lithography 2015 forum February 25th, 2015

European roadmap for graphene science and technology published February 25th, 2015

Nanomedicine

New Hopes for Treatment of Intestine Cancer by Edible Nanodrug March 2nd, 2015

Graphene Shows Promise In Eradication Of Stem Cancer Cells March 1st, 2015

Novel Method to Determine Optical Purity of Drug Components March 1st, 2015

Untangling DNA with a droplet of water, a pipet and a polymer: With the 'rolling droplet technique,' a DNA-injected water droplet rolls like a ball over a platelet, sticking the DNA to the plate surface February 27th, 2015

Discoveries

New Hopes for Treatment of Intestine Cancer by Edible Nanodrug March 2nd, 2015

Imec, Murata, and Huawei Introduce Breakthrough Solution for TX-to-RX Isolation in Reconfigurable, Multiband Front-End Modules for Mobile Phones: Electrical-Balance Duplexers Pave the Way to Integrated Solution for TX-to-RX Isolation March 1st, 2015

Imec Demonstrates Compact Wavelength-Division Multiplexing CMOS Silicon Photonics Transceiver March 1st, 2015

Graphene Shows Promise In Eradication Of Stem Cancer Cells March 1st, 2015

Announcements

New Hopes for Treatment of Intestine Cancer by Edible Nanodrug March 2nd, 2015

Imec Demonstrates Compact Wavelength-Division Multiplexing CMOS Silicon Photonics Transceiver March 1st, 2015

onic Present breakthrough in CMOS-based Transceivers for mm-Wave Radar Systems March 1st, 2015

Graphene Shows Promise In Eradication Of Stem Cancer Cells March 1st, 2015

Nanobiotechnology

Untangling DNA with a droplet of water, a pipet and a polymer: With the 'rolling droplet technique,' a DNA-injected water droplet rolls like a ball over a platelet, sticking the DNA to the plate surface February 27th, 2015

Bacteria network for food: Bacteria connect to each other and exchange nutrients February 23rd, 2015

Building tailor-made DNA nanotubes step by step: New, block-by-block assembly method could pave way for applications in opto-electronics, drug delivery February 23rd, 2015

Better batteries inspired by lowly snail shells: Biological molecules can latch onto nanoscale components and lock them into position to make high performing Li-ion battery electrodes, according to new research presented at the 59th annual meeting of the Biophysical Society February 12th, 2015

Research partnerships

Imec, Holst Centre and Renesas Present World’s Lowest Power 2.4GHz Radio Chip for Bluetooth Low Energy March 1st, 2015

Imec, Murata, and Huawei Introduce Breakthrough Solution for TX-to-RX Isolation in Reconfigurable, Multiband Front-End Modules for Mobile Phones: Electrical-Balance Duplexers Pave the Way to Integrated Solution for TX-to-RX Isolation March 1st, 2015

Imec Demonstrates Compact Wavelength-Division Multiplexing CMOS Silicon Photonics Transceiver March 1st, 2015

onic Present breakthrough in CMOS-based Transceivers for mm-Wave Radar Systems March 1st, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE