UCLA scientists eavesdrop on cellular conversations by making mice 'glow' with firefly protein

November 13, 2002

UCLA scientists coupled the protein that makes fireflies glow with a device similar to a home video camera to eavesdrop on cellular conversations in living mice. Reported in the Nov. 11 online edition of the Proceedings of the National Academy of Sciences, their findings may speed development of new drugs for cancer, cardiovascular diseases and neurological diseases.

Led by Dr. Sanjiv Gambhir, UCLA associate professor of molecular and medical pharmacology and director of the Crump Institute for Molecular Imaging, the team's research will allow scientists to study how cellular proteins talk to one another. These communications trigger changes that regulate a healthy body and cause disease when the signals go awry.

Gambhir and his colleagues used an optical camera equipped with the same kind of computer chip used in home video cameras to convert light into electrons. The team injected luciferase, the protein that makes fireflies glow, into cells, then injected the cells into the mouse.

They saw a remarkable sight. Each time two specific proteins spoke with each other, it activated the luciferase. The luciferase illuminated under the camera and produced brilliant flashes of light in the mouse.

"The mouse literally glowed under the camera," said Gambhir, a member of the UCLA Jonsson Cancer Center. "We 'heard' the proteins 'talk' by watching the communication pathways come to life."

"In the past, we had to extract an individual cell from an animal and use a microscope to study how cellular proteins communicated with each other," Gambhir said. "Now we can watch proteins in the same cell talking to each other in their natural setting."

"It's similar to when the switchboard operator used to eavesdrop on people's telephone conversations," he said. "Our technique enables us to listen in on multiple conversations in cells taking place deep within a living animal."

According to Gambhir, the discovery will enable researchers to create and evaluate new ways of treating human disease. "Human disease is often caused by a single misfiring during a series of intracellular communications," he said. "If we can understand and monitor what goes wrong, we may be able to develop drugs to block or improve cells' ability to process their proteins' internal conversations."

Cells rely on receptors that line their surfaces to communicate between the external world and their internal environment. Functioning like baseball catchers' mitts, the receptors continually grab and release different hormones and molecules that influence cellular communication activity.

"A cell receptor has no voice or vocal cord," Gambhir said. "It must plug into the cell's protein network to speak. One protein moves and acts on another, which sets off a chain reaction of conversations. Finally, the message reaches deep into the nucleus and tells the cells' genes what to do."

Gambhir said that the new system could be used to test drugs that target protein-to-protein interactions in mice or advance medical research with a new breed of mice that indicates when intracellular interactions take place. The method is non-invasive and does not harm or cause pain to the mouse.

"This technique can help us better understand the processes of many human diseases," Gambhir said. "For example, we can image new drugs for cancer that halt cell division and actually see whether or not they work in the living body. If the drugs don't stop cell growth, we can design better drugs and test them under the camera. The possibilities are endless."
-end-
The National Cancer Institute and Department of Energy funded the study. Gambhir's co-authors included R. Paulmurugan from UCLA and Y. Umezawa from the University of Tokyo.

University of California - Los Angeles

Related Cancer Articles from Brightsurf:

New blood cancer treatment works by selectively interfering with cancer cell signalling
University of Alberta scientists have identified the mechanism of action behind a new type of precision cancer drug for blood cancers that is set for human trials, according to research published in Nature Communications.

UCI researchers uncover cancer cell vulnerabilities; may lead to better cancer therapies
A new University of California, Irvine-led study reveals a protein responsible for genetic changes resulting in a variety of cancers, may also be the key to more effective, targeted cancer therapy.

Breast cancer treatment costs highest among young women with metastic cancer
In a fight for their lives, young women, age 18-44, spend double the amount of older women to survive metastatic breast cancer, according to a large statewide study by the University of North Carolina at Chapel Hill.

Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.

Stress in cervical cancer patients associated with higher risk of cancer-specific mortality
Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.

Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.

Moffitt Cancer Center researchers identify one way T cell function may fail in cancer
Moffitt Cancer Center researchers have discovered a mechanism by which one type of immune cell, CD8+ T cells, can become dysfunctional, impeding its ability to seek and kill cancer cells.

More cancer survivors, fewer cancer specialists point to challenge in meeting care needs
An aging population, a growing number of cancer survivors, and a projected shortage of cancer care providers will result in a challenge in delivering the care for cancer survivors in the United States if systemic changes are not made.

New cancer vaccine platform a potential tool for efficacious targeted cancer therapy
Researchers at the University of Helsinki have discovered a solution in the form of a cancer vaccine platform for improving the efficacy of oncolytic viruses used in cancer treatment.

American Cancer Society outlines blueprint for cancer control in the 21st century
The American Cancer Society is outlining its vision for cancer control in the decades ahead in a series of articles that forms the basis of a national cancer control plan.

Read More: Cancer News and Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.