Tumor Electric Field Therapy Inhibits TGF-β/C1R Signaling Axis-Driven Epithelial-Mesenchymal Transition in...

Glioblastoma (GBM) is one of the most aggressive and treatment-resistant primary brain tumors, with the mesenchymal subtype exhibiting particularly poor prognosis. Tumor electric field therapy (TEFT) has emerged as a promising adjunctive treatment, but its underlying molecular mechanisms remain incompletely understood.

GBM functional states were analyzed using CancerSEA datasets. GBM cell lines were treated with 200 kHz TEFT at 2.2 V/m for 72 h. C1R was knocked down using siRNA and shRNA. Cell morphology, migration, invasion, proliferation, and signaling pathways were assessed through various assays. Findings were validated in animal models and clinical specimens.

C1R was identified at the intersection of TEFT-downregulated genes, poor prognosis markers, and functional state genes. C1R was significantly upregulated in mesenchymal GBM and strongly correlated with epithelial-mesenchymal transition (EMT). Single-cell RNA sequencing revealed C1R was predominantly expressed in MES-like malignant cells with high EMT signature scores. TEFT treatment induced morphological changes from elongated spindle-shaped to rounded epithelial-like morphology, increased E-cadherin expression, and decreased mesenchymal markers (N-cadherin, Vimentin, YKL-40). Mechanistically, TEFT suppressed the TGF-β/SMAD2/3/STAT3 signaling pathway, downregulating C1R expression. C1R knockdown significantly reduced tumor growth in vivo, while exogenous TGF-β restored C1R expression and reversed the mesenchymal phenotype in a dose- and time-dependent manner.

TEFT inhibits GBM progression by suppressing the TGF-β/SMAD2/3/STAT3/C1R axis, thereby attenuating EMT and reducing tumor aggressiveness. These findings uncover a novel mechanism of TEFT and identify C1R as a potential biomarker and therapeutic target for GBM.