New Cancer Treatments Tested in Mice Stop Tumors in Their Tracks
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As long as scientists have known about cancer, they have been trying to develop a cure. Hundreds of potential treatments have been tried, and while some have shown promise, none have been 100% effective. New animal studies, however, are bringing researchers closer to finding a way to stop various types of cancer, by targeting the tumors themselves.
A Tumor-Fighting Sponge
Researchers at UCLA have developed a small sponge that, when implanted in mice, is effective in helping the body fight cancerous tumors.
The method uses a biodegradable sponge called a SymphNode, which targets regulatory T cells (Tregs), a type of immune cell that can by hijacked by cancer cells to protect themselves against attack by the body’s immune system.
Disabling Tregs systemwide can lead to autoimmune issues, so the sponge was designed as a way to wipe out Tregs just around a cancerous tumor. The SymphNode is filled with drugs that block Tregs and also attract anti-cancer T cells to the site.
Researchers tested the SymphNode in mouse models of breast cancer and melanoma. In both cases, when implanted next to a tumor, the SymphNode caused remission of the cancer, stopped the growth and spread of the tumors, and increased survival times.
In the breast cancer mice, the SymphNode shrank tumors in 80% of the tested mice and prevented tumors from spreading to other parts of the body. In the mice with melanoma, the SymphNode shrank tumors in all the tested mice, and in 40% it reduced the cancer to undetectable levels. The lifespan of both breast cancer and melanoma mice were up to double that of mice that did not receive the SymphNode implant.
To test the lasting effects of the SymphNode, the researchers introduced a second breast cancer tumor into mice that had previously received the SymphNode. The new cancerous tumor failed to grow, indicating that the SymphNode was still working to help the body fight the cancer.
The research team is working to refine the technique, with the hope that it could lead to a treatment for humans.
Fruit Juice as Tumor Inhibitor
Researchers from Okayama University in Japan have discovered that juice from the sarunashi fruit—a relative of kiwi fruit that is native to Japan, Korea, and parts of China and Russian—could help prevent and treat lung cancer.
Sarunashi, which is traditionally eaten in Japan for good health, contains more than 20 essential nutrients and vitamins and is high in antioxidants and anti-inflammatories.
To test its ability to prevent or reduce instances of lung cancer, researchers injected mice with NNK, a cancer-causing compound found in tobacco products, which caused the mice to grow lung cancer tumors. Then they gave some of the mice sarunashi juice, and found that the number of tumors in the mice given juice was substantially less than in those not given juice.
The results not only point to the promise of sarunashi juice, but also to the potential of other foods high in antioxidants and anti-inflammatories in the fight against cancer, and emphasizes the role diet plays in cancer and other chronic diseases.
Cleaning Out Residual Tumor Cells
When a tumor is removed, sometimes a few cells are left behind. If not treated, those cells can grow into a new tumor.
New preclinical research from the University of Pennsylvania has found a way to address those residual tumor cells to prevent cancer from reoccurring. The approach uses CAR T cell therapy, which uses the patient’s immune cells to attack their blood cancers.
In the study, researchers used mice that had experienced partial removal of cancerous tumors. The test was conducted with mouse models of both breast cancer and pancreatic cancer.
After applying a gel containing human CAR T cells to the surgical wounds of the mice, researchers observed that residual tumor cells were eliminated in almost all affected mice, preventing tumors from growing back. In the mice that did not receive the CAR T gel, the tumors regrew and the mice died within seven weeks. The mice that received the gel survived for the remainder of the observation period, and experienced no complications with healing or other side effects.
The results could lead to a new way to clear up residual cancer cells after surgery, by applying an anti-tumor treatment to tissues after tumor removal. The team plans to move on to a clinical trial in patients with breast cancer.
2 New Approaches to Brain Tumor Treatment
Two separate mouse studies—at Brigham and Women’s Hospital and Stanford University—show promise in treating and preventing glioblastoma, one of the most deadly types of brain tumor.
In the Stanford study, researchers implanted a small wireless device in the brains of mice. Once implanted, the device was remotely activated to injected cancer-killing nanoparticles into the tumor.
When tested on mice with brain tumors, treatment intervals of 15 minutes over 15 days while mice went about their normal activities was able to increase the survival rate of the mice.
The implant, if successful in humans, would enable doctors to treat glioblastoma tumors wirelessly and painlessly while the patient remains at home.
The Brigham and Women’s study takes a different approach, using a new cell therapy that not only helps wipe out existing tumors, but also prevent them from reoccurring.
Using genetic engineering, the researchers transformed live cancer cells into therapeutic tumor cells (ThTCs) that kill tumor cells and prompt the immune system to both attack existing tumors and prevent new ones from forming.
The team tested the new therapy in a mouse model of glioblastoma and found it both stopped tumors and gave the mice long-term immunity against new tumors. The results raise hope that the therapy could potentially be used to treat other types of cancer.
A 1-2-3 Punch for Pancreatic Tumors
Researchers at the University of Texas MD Anderson Cancer Center have developed a three-drug combo that works to treat pancreatic cancer in mice.
Each of the three drugs is an immunotherapy that targets a specific protein pancreatic tumors harness to suppress the immune system and keep it from attacking the cancer.
When the treatment was administered to 10 mice with highly aggressive pancreatic cancer, all but one lived for the entire 540 days of the study. By the end of the study, none of the nine living mice had any signs of cancer.
All three of the drugs used in the mouse study are in early-stage clinical trials, with the hope that the drug combo will be equally effective in humans with pancreatic cancer.
The American Cancer Society estimates that there will be almost 2 million new cancer cases diagnosed in the United States in 2023, and 609,820 cancer deaths. As researchers continue to discover new ways to fight cancer in all its forms, there is hope that many more of those cases will have a positive outcome.