• UCLA Health
  • myUCLAhealth
  • School of Medicine
U Magazine

U Magazine

U Magazine
  • Home
  • Current Issue
  • Centennial Campaign for UCLA Issue
  • Browse U Magazine
  • Letters to the Editor
  • Subscribe
  • Contact
  • UCLA Health
  • myUCLAhealth
  • School of Medicine

U Magazine

Browse U Magazine

  1. Home
  2. Browse U Magazine
Share this
The Cutting Edge

Scientists Use Nanoparticles to Shut Down Cancer Growth

  Scientists Use Nanoparticles to Shut Down Cancer Growth
 

Nucleic-acid agent siRNA can be attached to the outside of nanoparticles. The nanoparticles also contain pores where anti-cancer drugs also can be stored, enabling co-delivery of siRNA and anti-cancer drugs. In the current experiment, siRNA against TWIST was attached to mesoporous silica nanoparticle (MSN) coated with polyethyleneimine (PEI).
Illustration: Courtesy of Dr. Fuyu Tamanoi

In an advance toward developing a novel therapy for cancer, scientists from UCLA and the City of Hope used nanoparticles to deliver a nucleic acid known as small interfering RNA, or siRNA, into tumor cells to inhibit the expression of a specific protein and cause inhibition of tumor growth in an animal model.

The protein, TWIST, is a master regulator of a cancer program called epithelial-to-mesenchymal transition (EMT) that is implicated in tumor metastasis. Delivering siRNA into tumor-bearing mice inhibited the expression of TWIST, which in turn shut down the EMT program and dramatically reduced the size of tumors. “This demonstrates the effectiveness of targeting EMT for cancer therapy,” says Fuyu Tamanoi, PhD, professor of microbiology, immunology & molecular genetics and director of the signal transduction and therapeutics program at UCLA’s Jonsson Comprehensive Cancer Center.

In previous studies, siRNA has been shown to effectively shut down gene expression in tumor cells grown in the laboratory. But the technique had not been effective in living organisms because enzymes in the blood called nucleases degrade siRNA before it can reach tumor cells. To circumvent that problem, the UCLA and City of Hope researchers attached siRNA to the outside of a particular type of nanoparticle developed by Jeffrey Zink, PhD, professor of chemistry and biochemistry and a member of UCLA’s Jonsson Comprehensive Cancer Center. The nanoparticles are comprised of mesoporous silica coated with a substance called polyethyleneimine, which acts to bind and protect the siRNA when the particles are injected into the blood. As a result, the research team, led by Carlotta Glackin, PhD, at the City of Hope, found that the nanoparticles could accumulate in the tumor cells, and the siRNA could go to work inhibiting the cells’ expression of TWIST.

The study found that giving mice siRNA-loaded nanoparticles once a week for six weeks inhibited tumor growth and that it shut down not only TWIST, but also other genes under the control of the EMT process. The result confirms the critical importance of TWIST and the EMT process in cancer progression, the scientists say. TWIST is re-activated in a number of metastatic cancers, including triple-negative breast cancer, melanoma and ovarian cancer. By shutting down the EMT process, Drs. Zink, Tamanoi and Glackin may develop new therapy options for these cancers.

Another important finding was that shutting down TWIST expression enabled cancer cells to overcome their resistance to cancer drugs, suggesting that the therapy can be an effective way to sensitize cancer cells to anti-cancer drugs.

“Mesoporous Silica Nanoparticle Delivery of Chemically Modified siRNA against TWIST1 Leads to Reduced Tumor Burden,” Nanomedicine: Nanotechnology, Biology and Medicine, May 2015


Previous
Deadly Prostate-cancer Cells Have Stem-cell Qualities
Next
How Obstructive Sleep Apnea Damages the Brain


YOU ARE VIEWING

Winter 2016

Winter 2016
E-Brochure
Printable PDF
IN THIS ISSUE
  • The Essence of What We Are About
  • A Day to Remember
  • Genetic Testing All Women for Breast Cancer Might Not be Worth the Cost
  • To Kick Addiction, Replace It with Joy
  • Discovery of Molecular Signals Could Lead to Improved Stroke Recovery
  • New Method to Measure Artery Stiffness in the Brain
  • Wrist Fractures Could Foretell Future Breaks for Postmenopausal Women
  • Deadly Prostate-cancer Cells Have Stem-cell Qualities
  • Scientists Use Nanoparticles to Shut Down Cancer Growth
  • How Obstructive Sleep Apnea Damages the Brain
  • Keeping Gut Bacteria in Balance Could Help Delay Age-related Diseases
  • Building Sound Bodies and Sound Minds
  • Death Becomes a Matter of Choice
  • Do the Right Thing
  • Healing Art
  • Balance on a Blade’s Edge
  • Honors & Awards
  • In Memoriam
  • Reflections: Expanding the Definition of Beauty
  • Stitching for Advocacy
  • Postcard from Ethiopia
  • In His Own Words: Herb Rheingruber, MD ’65 (RES ’69)
  • Gift Benefits Migraine Research and Treatment
  • Good Friends Join Forces to Fight Cancer
  • UCLA Urology Celebrates Spielberg Family Gifts
  • UCLA Health System Board Meeting Explores Immunology
  • A First Look at the Future of Medical Education
  • A Vision for Healing
  • Mattel Party on the Pier a Wave of Success
  • Art of the Brain Honors Founder, Celebrates 16 Years
  • UCLA Cardiologists Serve Up Tips for a Healthy Heart
  • Operation Mend Honored at Pentagon’s Hall of Heroes
  • Gifts
  • In Memoriam
  • Chairs of Distinction
  • Back from the Streets
Like Us on Facebook Follow Us on Twitter Subscribe to Our Videos on YouTube Follow us on Instagram Connect with Us on LinkedIn Follow us on Pinterest
UCLA Health hospitals ranked best hospitals by U.S. News & World Report
  • UCLA Health
  • Find a Doctor
  • School of Medicine
  • School of Nursing
  • UCLA Campus
  • Directory
  • Newsroom
  • Subscribe
  • Patient Stories
  • Giving
  • Careers
  • Volunteer
  • International Services
  • Privacy Practices
  • Nondiscrimination
  • Billing
  • Health Plans
  • Emergency
  • Report Broken Links
  • Terms of Use
  • 1-310-825-2631
  • Maps & Directions
  • Contact Us
  • Your Feedback
  • Report Misconduct
  • Get Social
  • Sitemap
Like Us on Facebook Follow Us on Twitter Subscribe to Our Videos on YouTube Follow us on Instagram Connect with Us on LinkedIn Follow us on Pinterest

Sign in to myUCLAhealth

Learn more about myUCLAhealth