Immune evasive mechanisms in breast cancer micrometastasis

In metastasis, the existence of tumor cells overcoming the immune system during early organ seeding is crucial, yet the dynamics of tumor-immune interactions during micrometastasis remain unclear. Identifying the vulnerabilities of micrometastases before outbreaking into macrometastases can change t...

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Detalles Bibliográficos
Autor: Rozalén Miralles, Catalina
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/693613
Acceso en línea:http://hdl.handle.net/10803/693613
Access Level:acceso embargado
Palabra clave:Micrometastasis
Cancer immunoediting
Breast cancer
TIM3
Immune evasion
Immunoedició del càncer
Càncer de mama
Immunoevasió
616
Descripción
Sumario:In metastasis, the existence of tumor cells overcoming the immune system during early organ seeding is crucial, yet the dynamics of tumor-immune interactions during micrometastasis remain unclear. Identifying the vulnerabilities of micrometastases before outbreaking into macrometastases can change therapeutic opportunities for metastasis. Here, we report a novel function of TIM3 in tumor cells, leading micrometastasis survival and immune-escape. Examining the immune selective pressure in breast cancer (BC) metastasis mouse models, we unexpectedly found TIM3 among the most upregulated genes in metastatic surviving BC cells. The selection of TIM3+ tumor cells, is specifically occurring during early seeding of micrometastasis, escaping the immune attack and acquiring stemness. Single-cell RNA-seq of CD45+ immune cells revealed reprogramming of immunosuppressive γδ T cells in TIM3+ micrometastasis, licensing the immune escape metastatic outbreak. Mechanistically, TIM3 loss led to reduced b-catenin signaling in tumor cells, diminishing aggressiveness. Clinical data confirmed increased TIM3+ tumor cells in BC metastasis, and the presence of TIM3+ tumor cells conferred high risk of relapse and poor survival in BC patients. TIM3 blockade therapy reduced the metastatic seeding and overall metastasis in preclinical models. These findings provide a new understanding of micrometastasis and the potential use of TIM3 blockade therapies in subclinical metastasis.