What if you could use the immunity you already have against a common virus to fight cancer?
This idea, once thought unattainable, is now a tangible reality thanks to an innovative approach that uses mRNA vaccines, originally designed to prevent viral diseases, as tools to reprogram the immune system and directly target solid tumors.
A recent study conducted by an international team of scientists has demonstrated that mRNA vaccines can be administered directly into tumors, transforming the way the immune system detects and destroys cancer cells. This breakthrough could mark the beginning of a new era in oncology.
Behind this revolutionary work are researchers from renowned institutions such as the University of Hong Kong and key laboratories in Shenzhen. Among them, Drs. Renhao Li and Jian-Dong Huang led a collaborative effort to develop a therapy that combines basic science with clinical applications, all with a clear purpose: to transform cancer into a treatable and less devastating disease.
Inspired by advances in mRNA vaccines like Pfizer-BioNTech’s BNT162b2, which was widely used during the COVID-19 pandemic, the scientists decided to leverage the immune memory generated by these vaccines to attack tumors. The idea was simple yet bold: if the body already recognizes and responds to a specific antigen, why not tag tumor cells with that same antigen so the immune system can eliminate them?
The Method:
The experimental approach was carried out in animal models, specifically mice with various types of solid tumors (melanoma, colon, breast, and bladder). The key steps were as follows:
- Generation of immune memory: The mice were vaccinated with BNT162b2, which contains mRNA instructions for their cells to produce the spike protein of the SARS-CoV-2 virus. This ensured the mice developed specific immunity against this antigen.
- Tumor tagging: Once tumors were established, the vaccine was administered directly into them. This caused the tumor cells to express the spike protein, making them visible to the immune system.
- Immune attack: The immune system, already trained to recognize and destroy the spike protein, attacked the cancer cells. This process also triggered “antigen spreading,” stimulating responses against other tumor-specific antigens.
Game-Changing Results
The results were as impressive as they were encouraging:
– Tumor growth reduction: In all models studied, the size of treated tumors decreased significantly compared to controls.
– Systemic effect: Beyond targeting the treated tumor, the immune system also showed the ability to inhibit the growth of untreated tumors in the same organism, evidence of antigen spreading.
– Effectiveness in resistant tumors: Even in so-called “cold tumors,” which typically evade immune responses, the therapy transformed the tumor microenvironment into a “hot” one, characterized by inflammation and high immune activity.
– Successful combination: Combining this strategy with immune checkpoint inhibitors (anti-PD-L1) yielded even more striking results, including complete tumor elimination in some cases.
Safety: A Fundamental Pillar
A critical aspect of any new therapy is its safety profile, and this approach did not disappoint. No severe side effects or damage to healthy tissues were observed during the study. Furthermore, mRNA vaccines like BNT162b2 have already been widely studied and used in humans, further reinforcing their clinical viability.
Figure 1. Representation of the use of mRNA vaccines based on the SARS-CoV-2 Spike protein to reprogram the immune system and direct adaptive responses against solid tumors through intratumoral injections.
Future Implications: Beyond COVID-19
While this study focused on the COVID-19 vaccine, the researchers also explored the potential of using mRNA vaccines targeting other pathogens, such as hepatitis B virus (HBV) and common human coronaviruses (HCoVs). Initial results are promising, opening the door to personalized treatments based on a patient’s vaccination history or previous exposure.
This approach is not only innovative in its effectiveness but also in its speed and scalability. Unlike traditional personalized therapies, which are costly and take years to develop, this method leverages already available vaccines, drastically reducing the time required to reach patients.
The fight against cancer is changing. With science, dedication, and collaboration, we can transform this disease into a story of triumph and hope.
Main Reference:
Li, R., Hu, J. C., Rong, L., He, Y., Wang, X., Lin, X., Li, W., Wu, Y., Kuwentrai, C., Su, C., Yau, T., Hung, I. F., Gao, X., & Huang, J. D. (2025). The guided fire from within: intratumoral administration of mRNA-based vaccines to mobilize memory immunity and direct immune responses against pathogen to target solid tumors. Cell discovery, 10(1), 127. https://doi.org/10.1038/s41421-024-00743-3
Other References:
Chen, D. S., & Mellman, I. (2013). Oncology meets immunology: the cancer-immunity cycle. Immunity, 39(1), 1–10. https://doi.org/10.1016/j.immuni.2013.07.012
Aktar, N., Yueting, C., Abbas, M., Zafar, H., Paiva-Santos, A. C., Zhang, Q., Chen, T., Ahmed, M., Raza, F., & Zhou, X. (2022). Understanding of Immune Escape Mechanisms and Advances in Cancer Immunotherapy. Journal of oncology, 2022, 8901326. https://doi.org/10.1155/2022/8901326
Beatty, G. L., & Gladney, W. L. (2015). Immune escape mechanisms as a guide for cancer immunotherapy. Clinical cancer research : an official journal of the American Association for Cancer Research, 21(4), 687–692. https://doi.org/10.1158/1078-0432.CCR-14-1860
