Navigation Links
Fluorescent probes light up cancerous tumors

Building on his Nobel Prize-winning work creating fluorescent proteins that light up the inner workings of cells, a team of researchers led by Howard Hughes Medical Institute investigator Roger Tsien, PhD, professor of pharmacology, chemistry and biochemistry at the University of California, San Diego and the Moores UCSD Cancer Center has developed biological probes that can stick to and light up tumors in mice. The scientists were able to spot and remove more cancerous tissue in mice injected with the fluorescent probes than in those mice without the fluorescent probes, upping survival five-fold. The findings reported online the week of February 15 in the early edition of the Proceedings of the National Academy of Sciences are the latest steps in research aimed at helping surgeons see the outlines of cancerous tumors in real time, and promise to open new doors to using molecular tools in the operating room.

"The development of biological probes that can guide surgeons, rather than depending only on feel and normal 'white light' to see, can provide tools to navigate the body on a molecular level," said first author Quyen Nguyen, MD, PhD, assistant professor of surgery at the University of California, San Diego School of Medicine.

Surgeons often rely on feel, look and experience to tell if they have removed all of a tumor while sparing healthy tissue. While the patient lies on the operating table under anesthesia, tissue samples are quickly examined by pathologists, and remaining tumor tissue is sometimes missed, meaning further surgery or a greater likelihood of tumor recurrence. Tsien, Nguyen and colleagues used synthetic molecules called activatable cell penetrating peptides (ACPPs) and microscopic nanoparticles to develop probes carrying fluorescent and magnetic tags. These tags make tumors visible to MRI and allow the tumors to "glow" on the operating table. The team wanted to see if the probes could aid surgeons in seeing more of the tumor, particularly the margins.

In a series of studies, working mainly in mice with implanted human tumors, the researchers showed that if tumors had spread to surrounding tissue, the ACCP-nanoparticle probes enabled them to visualize areas of tumors that they wouldn't ordinarily see either because the tissue was buried beneath other tissue or the tumor simply was difficult to distinguish from normal tissue.

Using a technique called PCR (polymerase chain reaction) to measure tumor DNA, they found that, on average, 90 percent fewer cancer cells remained after surgery to remove tumors in mice using the probe-based molecular guidance compared to surgery without it a 10-fold reduction. They also found that the fluorescently labeled probes hit their mark 93 percent of the time, allowing the researchers to "see" left over tumor tissue.

According to the scientists, only a single injection of the nanoparticle-based probe containing the fluorescent and magnetic tags was needed in order to use MRI to examine the entire mouse model for tumors before and after surgery, in addition to the real-time guidance in surgery.

Nguyen said that in the future, additional tags may be added, and eventually, a cocktail of personalized probes may be designed for individual types of cancers. If the nanoparticle-based probes are successful in finding tumor cells in humans, the researchers envision using them eventually to deliver chemotherapy drugs to finish off the remaining cancer.

Tsien and Nguyen see many advantages to molecularly guided cancer surgery. Probes can be useful in staging cancer, particularly in prostate cancer, and can be used in a variety of tumor types. In addition, such biological probes can be used in laparoscopic and robotic surgery, where surgeons cannot feel the tumor, and rely much more on sight. If surgeons can completely remove a cancer, it may mean a patient could be cured quickly, and at relatively low cost when compared to long-term chemotherapy.


Contact: Steve Benowitz
University of California - San Diego

Related medicine news :

1. Fluorescent probes may permit monitoring of chemotherapy effectiveness, Stanford study shows
2. Naturally fluorescent molecules may serve as cancer biomarker
3. MBL scientist Osamu Shimomura wins Nobel Prize for discovery of green fluorescent protein
4. Fluorescent Retinal Cells Warn of Eye Disease
5. MEDRAD Multi Vendor Service Launches TotalRepair(SM) on Select Ultrasound Probes
6. Nanoscopic probes can track down and attack cancer cells
7. China Medical Technologies Announces the Receipt of SFDA Approval for Two of its FISH Probes and the Approval for the Hi-Tech Enterprise Status for its PRC Subsidiaries
8. Team probes why climbers die on Mount Everest
9. Study Probes Why Smokers Find It Hard to Quit
10. Study Probes Internet Health-Related Search Patterns
11. String probes for devastating childhood digestive disease
Post Your Comments:
(Date:10/13/2015)... ... 13, 2015 , ... The added calories and sugar in an average trick-or-treat ... a parent to do? Registered dietitians from Retrofit , the leading corporate weight ... year. , “Halloween is a high-calorie holiday,” said Dara Aronow, Registered Dietitian, Retrofit. ...
(Date:10/13/2015)... ... 2015 , ... Vision Group Holdings, the largest LASIK provider in North America, ... The LASIK Vision Institute and TLC Laser Eye Centers, Vision Group Holdings has performed ... correction. , Global Laser Vision will continue to operate in San Diego as it ...
(Date:10/13/2015)... ... October 13, 2015 , ... ... the United States, today announced the release of its limited edition holiday seasonal ... Cocktail Agua Fresca. All feature the unique flavor combinations and delicious taste Califia ...
(Date:10/13/2015)... ... 13, 2015 , ... ProText Kinetic Panel is a typography creation tool made ... can create energetic text animations in any layout without the use of keyframes. Using ... timeline and stylize the text. With intuitive on-screen controls, users can re-position and scale ...
(Date:10/13/2015)... Williamsport, PA (PRWEB) , ... October 13, 2015 , ... ... (SH) 2015 utility costs were 36 percent lower per square foot than in 2009. ... the actual cost of heating and cooling has decreased by eight percent. , ...
Breaking Medicine News(10 mins):
(Date:10/13/2015)... , Oct. 13, 2015  The spine division ... leader in musculoskeletal healthcare, will showcase its portfolio of ... Spine Society (NASS) annual meeting, October 14-17, 2015, in ... also host two clinical events: "Supplemental MIS ... Presentation Wednesday, October 14 12:30 – 1 p.m. ...
(Date:10/13/2015)... N.J. , Oct. 13, 2015  ContraVir ... the "Company"), a biopharmaceutical company focused on the ... announced the closing of its previously announced underwritten ... stock and warrants to purchase up to 3,000,000 ... fixed combined price to the public of $3.00. ...
(Date:10/13/2015)... JOLLA, Calif. , Oct. 13, 2015  Human ... revolutionize the practice of medicine, announced today the launch ... clinical research project that has the potential to transform ... San Diego, CA , at HLI,s headquarters ... in 2016 in other US and International cities. ...
Breaking Medicine Technology: