For a cancer as rare and difficult to treat as mesothelioma, innovative thinking is vital to making progress that helps survivors live longer and feel healthier.
While experimental therapies for this disease have harnessed genetically modified viruses, leopard frog eggs and laser-activated drugs, innovation doesn’t always come from exotic sources. Sometimes treatment breakthroughs are hiding in plain sight.
Take the veggies on your dinner plate, for example.
A research team has reported an anti-cancer vegetable compound called PEITC could have interesting therapeutic benefits for pleural mesothelioma patients.
The National Cancer Institute shows PEITC is found in cruciferous vegetables, a nutrient-rich family of plants that includes:
The medical journal Oncotarget recently published an article about a team of French researchers who confirmed for the first time that PEITC and the popular chemotherapy drug cisplatin make a powerful, cancer-fighting pair. While research shows both can kill mesothelioma cells on their own, the study shows they are even more effective when combined.
The study also found the combination is completely safe for healthy cells, suggesting it may have fewer side effects than standard chemotherapy.
Standard first-line treatment for mesothelioma involves combined treatment with chemotherapy drugs cisplatin and pemetrexed (Alimta). Several clinical trials show this combination is more effective than cisplatin alone, but the benefits are modest and side effects can be severe. About half of patients respond to that approach.
“Treatment of [pleural mesothelioma] represents a major public health challenge given its aggressiveness, poor prognosis after diagnosis and, more importantly, its lack of effective curative therapies,” Dr. Iza Denis, lead author of the article, said.
After a 2013 study identified the impressive combined effect of cisplatin and PEITC against lung cancer cells, Denis and colleagues sought to determine if the combination could also benefit mesothelioma patients.
Using a technique called the Uptiblue viability assay, researchers tested the compounds on nine mesothelioma cell lines and measured how many cancer cells died after exposure. They exposed the cells to several concentrations of the cisplatin-PEITC combination, as well as each compound on its own.
The experiment confirmed the combination is effective against mesothelioma cells. For one of the three concentrations tested, cisplatin-PEITC killed nearly 80 percent of cells, while each compound killed about 40 percent individually. When researchers increased the dose, more mesothelioma cells died.
Researchers also investigated how the cisplatin-PEITC combination affects healthy cells of the pleura, the protective lining around the lungs where pleural mesothelioma forms. They found the compounds were not toxic to healthy pleural cells, either alone or combined.
The experiment “clearly illustrates the safety of our strategy for healthy cells while inducing almost 100 percent [pleural mesothelioma] cell death,” Denis said. His team concluded it would be safe and feasible to develop cisplatin-PEITC into a local therapy that doctors could inject directly into the space between a patient’s lungs and pleura.
Local therapies, including radiation, target the site of the tumor more precisely than systemic therapies like chemotherapy, which spreads cancer-killing drugs throughout the body. Both approaches can have serious side effects when treatments harm healthy cells, a complication that cisplatin-PEITC avoids.
One reason patients respond poorly to cisplatin therapy is that cancer cells grow resistant to the drug, which may cause the treatment to fail. This effect is called chemoresistance, and it’s a major challenge for doctors and patients.
In the study, researchers observed that mesothelioma cells develop a resistance to both cisplatin and PEITC when given individually. Combined, however, the compounds remained effective over time and prevented the development of treatment-resistant cells.
“The combination not only led to a significant increase of cell death, but more importantly prevented the emergence of chemoresistance,” Denis said.
Because cisplatin-PEITC is safe, effective and can bypass resistance to chemotherapy, Denis and his research team believe it could be a promising new treatment strategy for mesothelioma.