Posts Tagged ‘cancer treatment’
Nanodrug Swarms Use The Human Body’s Biocommunications System to Coordinate Their Attack
Specifically, researchers have developed nanoparticles that can guide each other to a destination, resulting in a much more effective onslaught against a tumor.
Nanoparticles could be a boon for cancer treatment because they can travel through the body unimpeded, delivering drugs directly into tumors and lessening the side effects of chemotherapy. But they quickly disperse when they’re released into the body — even in the best cases, only about 1 percent of them reach their intended target, .
To improve this outcome, researchers from MIT, the Sanford-Burnham Medical Research Institute and the University of California-San Diego designed nanoparticles that can work in teams. One wave of nanoparticles homes in on a tumor, and when they arrive, they can communicate their location to the other nanoparticles still circulating in the body, helping them find the tumor too.
To do this, the nanoparticles take advantage of the body’s blood coagulation process, according to formal MIT doctoral student Geoffrey von Maltzahn, who is the lead author on a paper in Nature Materials describing this new work. At the site of an injury, blood clotting factors and other proteins interact in a chain of steps to form fibrin, which seals the wound and prevents further blood loss, as an MIT news release explains. The proteins not only bind to the area of an injury, but recruit other proteins to the area, von Maltzahn said.
“We’re trying to emulate that on the scale of synthetic particles, such that when one particle gets to the site of disease, it can communicate that event to expedite the subsequent arrival of other synthetic nanoparticles,” he explains in a video posted by MIT’s David H. Koch Institute for Integrative Cancer Research. (Watch it below.)
The researchers used two types of nanoparticles, which could either signal a message or receive it. The signaling particles flow through the bloodstream and arrive at the tumor site, where they trick the body into believing an injury has occurred (either by emitting heat or binding to certain proteins). This stimulates the natural fibrin-building process. Then the receiving nanoparticles, which carry a payload of cancer drugs, are outfitted with proteins that bind to fibrin. The fibrin acts as a homing beacon, helping the nanoparticles travel to the tumor site. They release the drugs once they get there, delivering a targeted blow to the cancer cells.
The researchers studied this method using mice and found that the communicating nanoparticles delivered 40 times more doxorubicin, a common chemotherapeutic, than a system that could not communicate.
MIT researchers are exploring how to test this system with existing clinical studies using nanoparticles.
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Weaponized Salmonella Could Be Used to Fight Cancer in the Gut
Human trials are already under way at the University of Minnesota, where researchers have successfully tested salmonella-led tumor control in mice.
It could be useful in the fight against cancers in the gut area, like the liver, spleen and colon. That’s where salmonella infects people anyway, so arming it with some cancer-killing weapons could make it easier to attack cancer cells in those spots.
Researchers at U of M’s Masonic Cancer Center modified some salmonella to make it less potent, and they added a hormone that is used to fight cancer, called Interleukin 2. The hormone identifies tumor cells as a threat and triggers an immune response, and it’s used to treat skin melanomas and kidney cancer, according to the .
Yale Univeristy scientists reported last month that salmonella is able to , which allows it to inject itself into cells and take them over. Salmonella doped with IL-2 would exploit this ability, enabling the delivery of the cancer-fighting hormone into the affected areas.
The bacteria also likes to , as scientists have known for some time. Bacterial tumor reduction is actually a pretty old idea, according to a U of M — in a published report from 1860s Austria, a patient with a large tumor was placed in the same room as someone with a bad infection, and the infection eventually spread to the tumor, shrinking it. The infection also killed the cancer patient, however.
Although the bacteria is “weaponized” in this study, the salmonella itself is weakened, so a person wouldn’t get sick.
Patients would just have to drink a few ounces of salmonella-filled water and the bacteria would make its way through the body.
It might not replace traditional treatments like chemotherapy and radiation, but it wouldn’t have their nasty side effects. At the very least, it could be one more weapon in the arsenal against cancers in the gut.
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High-Powered NASA Grow-Light Reduces Chemotherapy Side Effects
WARP 75 lamp eases pain
The technology is called High Emissivity Aluminiferous Luminescent Substrate, or “HEALS,” and in a clinical trial, it used the equivalent energy of a dozen suns to alleviate a condition called oral mucositis, essentially mouth and throat sores. Patients who take chemo drugs have a high incidence of mucositis, which can be so painful that they can’t eat solid foods.
HEALS was initially developed as a plant growth chamber for shuttle missions. It uses LEDs that emit long wavelengths of light, stimulating cells to grow (or to aid in healing). The LEDs emit plenty of photons, but no heat, according to NASA.
The study used a WARP 75 light-delivery system, which provides the equivalent light energy of 12 suns from each of 288 LED chips, each the size of a grain of salt. There’s no heat, just lots of energy.
In a two-year, double-blind trial, researchers tested the light therapy on 20 cancer patients at Children’s Hospital of Wisconsin, and 60 patients from the University of Alabama at Birmingham. The patients all had bone marrow transplants or stem cell transplants. They were organized into groups at low and high risk of developing mucositis. At random, half of each risk group received HEALS treatment and half were treated with a placebo device that had no therapeutic effects.
Nurses held the devices close to patients’ left and right cheek and neck for 88 seconds each, every day for two weeks at the start of the bone marrow or stem cell transplant. Patients filled out a form to describe their levels of pain, and doctors and nurses checked their mouths for signs of mucositis.
Ultimately, they found the patients with real HEALS treatment experienced less pain, NASA said. There’s a 96 percent chance this was a direct result of the light therapy, according to the study.
Doctors say the treatment could offer several benefits, including better nutrition, less drug use and improved morale, which can all help patients improve faster.
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A Protein Killer Could Treat All Cancers, and Possibly All Illnesses
The biotech company Alnylam announced in June that its drug ALN-VSP cut off blood flow to 62 percent of liver-cancer tumors in those 19 patients, by triggering a rarely used defense mechanism in the body to silence cancerous genes. Whereas conventional drugs stop disease-causing proteins, ALN-VSP uses RNA interference (RNAi) therapy to stop cells from making proteins in the first place, a tactic that could work for just about any disease. “Imagine that your kitchen floods,” says biochemist and Alnylam CEO John Maraganore. “Today’s medicines mop it up. RNAi technology turns off the faucet.”
Here’s another analogy: If DNA is the blueprint for proteins, RNA is the contractor. It makes single-stranded copies of DNA’s genes, called mRNA, which tell the cell to produce proteins. In 1998, scientists identified RNAi, a mechanism that primitive organisms use to detect and destroy virus’s double-stranded RNA and any viral mRNA. Mammals’ immune systems made RNAi’s antiviral function irrelevant (although all vertebrates, including humans, still use RNAi to regulate mRNA activity), but researchers found that introducing small segments of double-stranded RNA to cells could trigger the ancient mechanism and selectively halt the production of specific proteins.
That ability makes RNAi a potential fix for many diseases, including cancer, that arise when abnormal cells produce excessive amounts of everyday proteins. In theory, manipulating RNAi to kill proteins is simple. ALN-VSP, for example, consists of synthetic double-stranded RNA designed to match tumor mRNA that codes for two proteins: VEGF, which cancers overproduce to help grow new blood vessels, and KSP, which sets off rapid cell division. The researchers send the synthetic RNA into liver cells, and the body’s RNAi system kills both the synthetic RNA and any matching tumor-grown mRNA. Knock out the mRNAs coding for those proteins—which in the liver are produced only by cancer cells—and the tumor stops growing.
“We can turn off any one of 20,000 genes with RNAi,” says Bruce Sullenger, a molecular biologist researching RNAi at Duke University. “The challenge has been to get a drug into only the desired cells and not harm others.” Researchers have worried that a drug might disrupt normal protein production in a healthy cell, or that the immune system will destroy the drug before it reaches its target.
Alnylam overcame both concerns by packaging the drug in a fatty envelope that is absorbed primarily by the liver. This allowed doctors to administer the drug through the blood, rather than by an injection to one spot, which improves results by ensuring that the entire liver receives an even dose.
The technique’s ability to attack single genes could lead to drugs for the 75 percent of cancer genes that lack any specific treatment, as well as for other illnesses. Alnylam is already testing RNAi therapy for Huntington’s disease and high cholesterol in cell cultures; other researchers are tackling macular degeneration, muscular dystrophy and HIV. The potential has driven nearly every major pharmaceutical company to start an RNAi program.
Because the approach is fundamentally simple, RNAi therapy could be ready within two years, say experts including John Rossi, a molecular geneticist at City of Hope National Medical Center in California. Alnylam plans to enroll an additional 36 patients in the ALN-VSP trial and increase the dosage, but the early results are good enough to suggest that it could be among the first RNAi therapies to hit the market. “I think RNAi could work for anything,” Rossi says. “But even if it only works for liver cancer, it would be pretty good.” For liver-cancer patients who have been failed by chemotherapy and radiation and felt their harsh side effects, that would be wonder drug enough.
Combining Two Competing Cancer Drugs, Study Finds Rare 100% Response Rate
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First of all, it seems pharmaceutical companies are moving away from the more cost-effective one-size-fits-all approach to drug development and embracing the long tail of cancer treatments, engineering drugs that only work for a small percentage of patients but that work very effectively within that group.
Pfizer announced that one such drug it’s pushing into late-stage testing is targeted for just 4% of lung cancer patients. But more than 90% of that tiny cohort responded to the drug in initial tests, and 9 out of ten is getting pretty close to the ideal ten out of ten. By gearing drugs toward more boutique treatments rather than broad umbrella pharmaceuticals that try to work for everyone it seems cancer researchers are making some headway. But how can we close the gap on that remaining ten percent?
Ask Takeda Pharmaceutical and Celgene, two drug makers who put aside their competitive interests to test a novel combination of their treatments. In a test of 66 patients with the blood disease multiple myeloma, a full 100 percent of the subjects saw their cancer reduced by half. Needless to say, a 100 percent response to a cancer drug (or in this case, a drug cocktail) is more or less unheard of. Moreover, this combination never would’ve been tried if two competing companies hadn’t sat down and put their heads together.
Are there more potentially effective drug combos out there separated by walls of competitive interest and proprietary information? Who’s to say, but it seems like with the vast amount of money and research being pumped into cancer drug development, the odds are pretty good. And if researchers can start pushing more of their response numbers toward 100 percent, we can more easily start talking about oncology’s favorite four-letter word: cure.
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