Northwestern Medicine researchers have uncovered a surprising link between COVID-19 infection and cancer regression, potentially paving the way for novel cancer treatments. The study, published in The Journal of Clinical Investigation, reveals that RNA from the SARS-CoV-2 virus triggers the development of a unique type of immune cell with anti-cancer properties.
Inducible Nonclassical Monocytes (I-NCMs)
These newly identified cells, termed inducible nonclassical monocytes (I-NCMs), demonstrate the ability to attack cancer cells. According to Ankit Bharat, MD, chief of Thoracic Surgery at Northwestern Medicine, these cells could potentially be harnessed to treat cancers resistant to current therapies. The discovery may explain the reported regression of certain cancers following COVID-19 infection.
"This discovery opens up a new avenue for cancer treatment," said Bharat. "We found that the same cells activated by severe COVID-19 could be induced with a drug to fight cancer, and we specifically saw a response with melanoma, lung, breast and colon cancer in the study. While this is still in the early stages and the effectiveness was only studied in preclinical animal models, it offers hope that we might be able to use this approach to benefit patients with advanced cancers that have not responded to other treatments."
The study utilized both human tissues and animal models, revealing that these unique immune cells can be pharmacologically stimulated using small molecules. This presents a potential new therapeutic option, especially for patients with aggressive or advanced cancers who have exhausted traditional treatments like immunotherapies.
Mechanism of Action
The investigators found that during COVID-19, a special subset of immune cells can be stimulated. The viral RNA activates signals in the immune system, transforming common monocytes into I-NCMs. These cells can move into blood vessels and surrounding tumor tissue, a capability most other immune cells lack.
"What makes these cells so special is their dual capability," Bharat explained. "Typically, immune cells called non-classical monocytes patrol blood vessels, looking for threats. But they can’t enter the tumor site itself due to the lack of specific receptors. In contrast, the I-NCMs created during severe COVID-19 retain a unique receptor called CCR2, allowing them to travel beyond blood vessels and infiltrate the tumor environment. Once there, they release certain chemicals to recruit body’s natural killer cells. These killer cells then swarm the tumor and start attacking the cancer cells directly, helping to shrink the tumor."
Future Directions
Bharat emphasizes that further research is needed before this approach can be translated to clinical settings. The team plans to conduct clinical trials to assess the safety and efficacy of using these findings to treat cancer patients.
The research may also play a role in the Canning Thoracic Institute’s Double Lung Replacement and Multidisciplinary Care (DREAM) Program, which provides double-lung transplants to select patients with advanced lung cancers. According to Bharat, the monocyte research could potentially treat DREAM patients without risking rejection of their new lungs.
The research was funded by the National Institutes of Health (NIH) and the Canning Thoracic Institute.
