Cells in the human body chat with each other all the time. One major way they communicate is by releasing tiny spheres called exosomes. These carry fats, proteins, and genetic material that help regulate everything from pregnancy and immune responses to heart health and kidney function.
“Exosomes work like text messages between cells , sending and receiving information,” said lead researcher Ke Cheng, PhD, professor of biomedical engineering at Columbia. “The significance of this study is that exosomes can bring mRNA-based treatment to lung cancer cells locally, unlike systemic chemotherapy that can have side effects throughout the body. And inhalation is totally noninvasive. You don’t need a nurse to use an IV needle to pierce your skin.”
Dr. Cheng expects a human trial could launch within 5 years. For now, his study is attracting attention because it marks an advance in three areas of intense interest by researchers and biotech companies alike: Therapeutic uses of exosomes, inhalable treatments for lung conditions, and the safe delivery of powerful interleukin-12 (IL-12) immunotherapy.
Inside the Study
Dr. Cheng, who has been developing exosome and stem cell therapies for more than 15 years, and his lab team focused on lung cancer because the disease, often detected in later stages, “has a huge mortality rate,” he said. “Therapies have been suboptimal and leave the organ so damaged.”
He wanted to explore new alternatives to systemic treatments. Most are given intravenously, but Dr. Cheng thinks exosomes — also called extracellular vesicles (EVs) — could change that.
“One of the advantages of exosomes is that they are naturally secreted by the body or cultured cells,” he noted. “They have low toxicity and have multiple ways of getting their message into cells.”
The scientists borrowed an approach that captured public attention during the pandemic: Using messenger RNA, which directs cells to make proteins for tasks — including boosting immune response.
IL-12 has shown promise against cancer for decades, but early human trials triggered serious side effects and several deaths. Researchers are now trying new delivery methods that target tumor cells without affecting healthy tissue. Dr. Cheng’s team took a new approach, inserting mRNA for IL-12 into exosomes.
One aim of the study was to compare the effectiveness of inhaled exosomes vs inhaled liposomes, engineered fat droplets also under investigation as drug carriers. The team’s question: Which would work better at introducing IL-12 to the lungs to affect cancer, without triggering side effects?
After lab mice inhaled the particles through the nose, the researchers found that exosomes delivered more mRNA into cancer cells in the lungs and fought lung cancer with few side effects. Three days after treatment, researchers saw an influx of cancer-fighting T cells within tumors — with higher levels for exosome-based treatment. Plus, the exosomes led to more cancer-destroying nature killer cells and more monocytes, a sign of immune-system activation.
Researchers also found the treatment acted as a vaccine, training the immune system to battle newly introduced cancers. Little of the exosome-delivered drug escaped into the bloodstream, and the study found minimal side effects. Inhalation didn’t affect normal breathing, Dr. Cheng added.
The study’s use of inhaled exosomes makes it significant, said Raghu Kalluri, MD, PhD, professor and chair of the Department of Cancer Biology at MD Anderson Cancer Center. “This is an interesting study that explores the inhalable delivery of engineered EVs for the treatment of lung cancer and offers insights into focused delivery of EV-based drugs…with implications for diseases beyond cancer,” he said. Dr. Kalluri is also an exosome researcher.