A drug that millions of people already use for asthma and allergies may one day become part of cancer treatment, according to a new study from Northwestern Medicine.
Researchers discovered that medications blocking a molecule called CysLTR1 may help the immune system fight aggressive cancers that often resist modern immunotherapy treatments.
The findings were published in Nature Cancer and could eventually lead to faster clinical testing because some of the drugs involved, including montelukast, are already approved for treating asthma.
Immunotherapy has become one of the biggest advances in cancer treatment over the last decade. Unlike chemotherapy, which directly attacks rapidly growing cells, immunotherapy works by helping the body’s own immune system recognize and destroy cancer cells.
For some patients, immunotherapy can produce dramatic long-term results. However, many cancers eventually learn how to escape the immune system or stop responding to treatment.
This problem is especially common in aggressive cancers such as triple-negative breast cancer, melanoma, ovarian cancer, and certain other advanced tumors.
Scientists have been trying to understand why some tumors become resistant to immunotherapy and how they manipulate the immune system to survive.
The new study focused on neutrophils, a type of white blood cell that normally helps defend the body against infections.
Neutrophils are usually considered part of the body’s natural protection system. But researchers found that tumors can effectively “reprogram” these immune cells and turn them into helpers that support cancer growth instead of fighting it.
At the center of this process is a molecule called CysLTR1.
This molecule is already well known in allergy and asthma medicine because it helps control inflammation. Drugs like montelukast block CysLTR1 and are widely prescribed to reduce asthma symptoms and allergic reactions.
The Northwestern team discovered that many tumors appear to exploit this same pathway to weaken the immune response against cancer.
Dr. Bin Zhang, senior author of the study and professor of cancer immunology at Northwestern University Feinberg School of Medicine, described CysLTR1 as a kind of switch that controls how neutrophils behave around tumors.
When researchers turned off this switch, either genetically or by using drugs such as montelukast, the immune system became better able to attack cancer again.
The study combined several types of experiments. Researchers used mouse models of different cancers, examined human immune cells, analyzed tumor samples from patients, and studied large cancer databases.
The mouse experiments included triple-negative breast cancer, melanoma, ovarian cancer, colon cancer, and prostate cancer.
In many cases, blocking CysLTR1 slowed tumor growth, improved survival, and restored the effectiveness of immunotherapy treatments. This even happened in cancers that had already stopped responding to immunotherapy.
One particularly important finding involved the behavior of neutrophils.
Rather than simply destroying these cells, the treatment appeared to retrain them. Harmful neutrophils that were helping tumors survive became cells that once again supported immune attack against cancer.
Researchers say this is important because neutrophils are among the most abundant immune cells in the body. Reprogramming them could potentially produce broad effects on the tumor environment.
The scientists also found that patients with higher CysLTR1 activity often had poorer survival and weaker responses to immunotherapy across several cancer types.
This suggests that the pathway may play an important role in cancer progression and treatment resistance.
The discovery is generating excitement partly because the drugs involved already exist. Developing completely new cancer drugs can take many years and cost enormous amounts of money. Since montelukast is already FDA-approved for asthma, researchers may be able to move more quickly into human cancer trials.
However, scientists caution that much more research is still needed before patients should view asthma drugs as proven cancer treatments.
The researchers now hope to identify which patients are most likely to benefit and determine how best to combine these medications with existing immunotherapy approaches.
They also plan to study the biological mechanisms more closely to understand how tumors manipulate neutrophils and whether similar strategies may help in additional cancer types.
The study reflects a growing trend in cancer research that focuses not only on cancer cells themselves but also on the immune environment surrounding tumors.
Researchers increasingly believe many cancers survive by controlling nearby immune cells and turning them against the body’s natural defenses.
If you care about cancer, please read studies about how to fight cancer with these anti-cancer superfoods ,and a berry that can prevent cancer, diabetes and obesity.
For more health information, please see recent studies about how to harness the power of anti-cancer foods and supplements, and cancer-fighting foods and recipes.
Source: Northwestern Medicine.
