Immune cells that normally repair body tissues can be tricked by tumors when cancer begins to form in the lungs and instead help the tumor become invasive , according to a discovery published by scientists at Mount Sinai Hospital. of New York in the magazine ‘ Nature’ .
The researchers found that early-stage lung cancer tumors co-opt immune cells, also known as tissue-resident macrophages, to help invade lung tissue. They also mapped out the process, or program, of how macrophages allow a tumor to damage tissues that the macrophage normally repairs. This process allows the tumor to hide from the immune system and proliferate into the later, deadly stages of cancer.
Macrophages play a critical role in the formation of the tumor microenvironment, the ecosystem that surrounds tumors in the body. By investigating this microenvironment, researchers can find key players that drive tumor growth that can be tested as targets for immunotherapy. But modifying macrophages therapeutically has been difficult.
In this study, scientists studied tissue samples from lung cancer tumors and surrounding lung tissue in 35 patients to see the role of macrophages in tumor development.
The study’s lead author, Dr. Miriam Merad, director of the Institute for Precision Immunology at the Icahn College of Medicine at Mount Sinai, and a multidisciplinary team of thoracic surgeons, pathologists, and medical oncologists from the Institute of Thoracic Oncology devised a comprehensive study that It began when patients entered the operating room to have their cancerous lesions removed.
Patient lung tumor samples, surrounding healthy lung tissue samples, and blood samples were immediately analyzed at the cellular level at the Mount Sinai Human Immune Surveillance Center to determine the immune system components they contained.
The researchers identified the macrophages involved in the early development of lung cancer, identifying a possible target for the development of future drugs . They also found that the process that allows macrophages to help tumors invade lung tissues is present in mice as well, allowing them to manipulate macrophages in future mouse models knowing that manipulation is relevant to humans.
Half of early-stage lung cancers relapse, and once they do so and reach more advanced stages, they are fatal and irreversible. Knowing how to attack cancer at an early stage could have a huge impact on the number of patients who relapse and their overall survival.
“These findings are very important to Mount Sinai going forward, as we have a very powerful lung cancer screening program that identifies patients with early lung cancer lesions before they become fully invasive.” says Dr. Merad, director of the Center for Human Immune Surveillance and a member of the Institute of Thoracic Oncology and the Mount Sinai Tisch Cancer Institute. “These findings will help design immunoprevention strategies to prevent tumor progression in at-risk patients by reprogramming macrophages and removing the tumor without the need for surgery.”
