A new way to define edges of tumors? & to deliver chmeo?

One Doctor’s Quest to Save People by Injecting Them With Scorpion Venom

One Doctor’s Quest to Save People by Injecting Them With Scorpion Venom
http://www.wired.com/2014/06/scorpion-venom/

A pediatric cancer nurse out in Seattle and has been working on this project. She tells this lady it is currently being used in Australia in adult melanoma patients and seeing positive results.

Brendan I. Koerner Magazine

• 06.24.14

One Doctor’s Quest to Save People by Injecting Them With Scorpion Venom

http://www.fredhutch.org/en/labs/project-violet.html

A decade-long quest to solve one of the most vexing problems in oncology: the fact that a tumor’s precise boundaries are nearly impossible to define during surgery.

A preoperative MRI provides only a rough guide to a tumor’s fuzzy edges; the scans often miss slivers of cancer that seamlessly blend into the surrounding tissue. Surgeons often face a brutal catch-22: Either cut out any suspicious tissue, an approach that can lead to debilitating side effects, or risk leaving behind malignant cells that will eventually kill the patient.

Olson tells the students that he finally has a solution. His laboratory at the renowned Fred Hutchinson Cancer Research Center, located just down the road by Seattle’s Lake Union, has developed a compound that appears to pinpoint all of the malignant cells in a patient’s body. It gives those cells a bright fluorescent sheen, so that surgeons can easily spot them in the operating room. Olson calls the product Tumor Paint, and it comes with a surprising twist: The compound’s main ingredient is a molecule that is found in the stinger of Leiurus quinquestriatus, a potent little animal more popularly known as the deathstalker scorpion.

Olson thought he could accomplish this feat by modifying a molecule known to bind specifically to cancer cells. If he could attach a fluorescent dye to such a molecule, maybe he could make the tumors glow a brilliant blue or green when viewed through a near-­infrared camera positioned next to the operating table. Surgeons would then have no problem seeing exactly where a tumor began and ended.

Ullrich hypothesized that the tumors could be held in check if there were a drug capable of blocking their ability to “sweat” chloride. Chlorotoxin promised to do just that.

When she injected chlorotoxin into the brains of mice with gliomas, Ullrich found that the peptide would bind only to the cancer cells; the molecule wanted nothing to do with the normal cells adjacent to the tumors.

the chlorotoxin didn’t attach just to brain tumors—it grabbed onto all sorts of cancers, from those that affect the skin to those that destroy the lungs. They also learned that the peptide could cross the barrier that protects the brain from toxins and other chemicals—a rare attribute for a molecule of its size.

In one instance, the chlorotoxin illuminated a clump of just 200 malignant cells that were burrowed deep within a wad of fat. “That was the point we learned that the technology was far more sensitive than an MRI,”

Blaze launched the first human clinical trial of Tumor Paint in December 2013; a second Phase I trial is slated to begin later this year.

Olson’s tattoo is a tribute to not only chlorotoxin but also a range of similar peptides that he’s now investigating as possible weapons against cancer and other diseases. Using a custom-written Python program that can troll through decades’ worth of genomic databases on venoms, his lab has identified hundreds of thousands of mol­ecules that share chloro­toxin’s central knot of disulfide bonds and thus may form the basis for new cancer-­fighting drugs.

Painting Tumors

Brain surgeons can’t easily distinguish a tumor from healthy tissue. Jim Olson’s Tumor Paint solves this problem by giving tumors an eerie and distinct fluorescent glow. —Jason Kehe

Step 1 Olson needed a compound that would locate only tumor cells. The answer: chlorotoxin, a (nontoxic to humans) mol­ecule found in the venom of the deathstalker scorpion.

Step 2 Chemists attach a fluorescent dye—the FDA-­approved indo­cyanine green (a)—to laboratory-­made chlorotoxin (b). The resulting compound glows in near-­infrared light.

Step 3 Before surgery, Tumor Paint—which can cross the blood-brain barrier—is injected into the patient’s bloodstream through an IV and begins circulating within the body.

Step 4 The outsides of tumor cells contain a protein healthy cells don’t: Annexin A2 (a). Research shows chlorotoxin (b) binds to Annexin A2 and from there seeps into tumor cells (c).

Step 5 It can take an hour or two for enough of the compound to accumulate in a tumor to be useful. Even then surgeons still can’t see their targets with the naked eye. Instead, they point a near-­infrared laser at the area—often in the hard-to-operate-on brain—and a special camera captures the light emitted from the Tumor Paint. Tumors appear on a monitor as ghostly-­green blobs.