Researchers have succeeded in developing a treatment that is injected directly into the tumor, and works to reprogram the immune cells present in it, transforming them into active cells capable of attacking the cancer from within.
This new approach redefines the concept of the tumor, as it is no longer just a target for treatment, but has become an arena in which immunotherapy itself is built, without the need to produce modified cells outside the patient’s body.
The study, published in the journal ACS Nano, showed that immune cells within solid tumors were able to absorb the therapeutic payload and began producing proteins that enable them to recognize and attack cancer cells.
This research was led by a team from the Korea Advanced Institute of Science and Technology (KAIST) under the supervision of Professor Ji-ho Park, who documented the transformation of cells that were inhibited by the influence of the tumor into effective agents in eliminating it.
Conventional immunotherapies face significant difficulties in solid tumors due to the density and compactness of the tissue, with studies indicating that only a small percentage of modified immune cells reach the tumor core. But this new approach takes advantage of the presence of large numbers of macrophages within the tumor, which often make up about half of its mass.
The treatment relies on delivering a temporary genetic message (mRNA) via lipid nanoparticles, which prompts macrophages to produce new receptors that distinguish cancer cells from healthy ones. Since these cells are already moving inside the tumor, they bypass barriers that hinder most other treatments.
In experiments on mice with skin cancer (melanoma), the treatment slowed the growth of tumors and triggered an immune response that extended to tumors that were not directly injected. Although the results are promising, the researchers stress that there is still a long way to go before clinical application, with the need for careful safety trials and careful selection of immune targets.
