Exosomes: moving cancer research forward ~100 nm at a time

Fredrik Vannberg

When Professor Frederik Vannberg talks about exosomes, his enthusiasm regarding these once-neglected microvesicles and their potential role in cancer therapeutics is undeniable. Vannberg’s primary focus is the genomics of disease and his recent research to understand the role of exosomes during the immune response underscores the potential for using these particles to deliver novel therapeutics into the lymph nodes of cancer patients.

Essentially, exosomes released from cancer cells affect the microenvironment effectively promoting tumor cell proliferation. The body’s immune response is suppressed resulting in the deregulation of tumor recognition and related anti-tumor functions. 

Dr. Vannberg and his colleagues recently published a paper demonstrating that exosomes derived from cells stimulated by the immune system can rapidly relay messages to the lymphatic system, including the onset of cancer. “This is an important aspect of how we might deliver therapeutics,” he explains. “Perhaps there is potential to modify exosomes and have them quickly shuttle therapeutics to the lymph nodes.”   

“Although exosomes look the same, their effector functions vary based on how they were derived.”

He goes on to explain one of many interesting qualities of exosomes is that they can transmit information to distant parts of the body—through both the lymphatic and circulatory system. Researchers have known for some time that exosomes have different roles when released from different cells. The key is being able to distinguish between the good ones and the bad ones and to do this, we need a deeper understanding of what’s in the packages. Despite the exciting progress, there is still work to be done to understand the potential of exosomes as therapeutics for complex diseases.

It’s a small world

Tackling a huge problem like cancer with the help of microparticles less than 100 nanometers in size is no small feat, particularly when you consider the challenges of isolating exosomes for study. There are various ways to purify exosomes, and Vannberg and his colleagues have tried many of them. In the end, they chose the ‘classic’ method of ultracentrifugation, calling it “hands-down the best approach in terms of consistency, purity and yield.”

“It’s important how you purify these nanoparticles,” he explains. “There’s a large number of different types of nanovesicles and microvesicles in serum, blood and other fluids. Ultracentrifugation has yielded very high purity, enabling us to separate out exosomes from microvesicles that are only slightly larger. And we believe ultracentrifugation provides a higher yield that isn’t achievable with other techniques."

But how Dr. Vannberg and his associates obtain exosomes for study is not the cause of his enthusiasm. It’s the potential for exosomes to revolutionize the way we attack diseases. In fact, he’s confident the greatest exosome-related breakthroughs in the near future will be related to new therapeutics.

“I'm excited to be a part of the effort to discover how exosomes might be able to target not only cancers but also other pathogens that are evolving in our world,” he says. “Maybe we can use exosomes to target Ebola, Zika and other viruses that could lead to potential pandemics. “That would be an astounding breakthrough.”