Single-Cell RNA Sequencing Reveals Interaction Between Fibroblast Gene Signature and T-Cell Infiltration in Muscle-Invasive Bladder Cancer - Expert Commentary
A recent study by Liu et al. investigated the interactive mechanisms between cancer-associated fibroblasts (CAFs) and exhausted T cells (T-ex) in MIBC. Single-cell RNA sequencing of 19 tissue samples from 12 patients (7 MIBC, 3 non-muscle-invasive bladder cancer, and 9 normal tissue samples) identified 13 transcriptionally distinct fibroblast clusters and 10 functionally heterogeneous T-cell subsets. Two interferon (IFN)-responsive fibroblast populations, F-ISG15 (inflammatory CAFs) and F-POSTN (myofibroblastic CAFs), were predominant in the MIBC microenvironment. Experimental data demonstrated that IFN-γ secreted by T-ex cells polarizes CAFs to secrete CXCL12, which then recruits CXCR4-expressing T cells via the CXCL12-CXCR4 chemotactic axis (p < 0.05).
Interestingly, the authors demonstrated through spatial analysis a bi-directional interaction loop in which T-ex-derived IFN-γ sustains CAF activation, while CAF-secreted CXCL12 amplifies Te-x infiltration. T-ex cells exhibited high expression of exhaustion markers HAVCR2, LAG3, TIGIT, and CTLA4, with CD8 T-ex subtype displaying increased IFN-γ expression. Clinically, activated CAF signatures were associated with advanced disease stages and reduced patient survival in MIBC (p < 0.001).
These findings suggest a novel CXCL12 and IFN mediated signaling circuit as a potential therapeutic target, offering new strategies to disrupt immunosuppressive tumor microenvironment crosstalk and improve outcomes for MIBC patients.
Written by: Bishoy M. Faltas, MD, Chief Research Officer, Englander Institute for Precision Medicine, Gellert Family - John P. Leonard, MD, Research Scholar, Associate Professor of Medicine, Cell and Developmental Biology, Weill Cornell Medicine, New York- Presbyterian Hospital, NY
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