Prognostic value and potential upstream regulator of Schwann cells in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a major malignancy of the upper gastrointestinal tract. Owing to limited actionable therapeutic targets, long-term outcomes remain unsatisfactory. This study aimed to investigate the prognostic value of non-myelinating Schwann cells (nmSCs) infiltration in ESCC and to identify potential upstream regulators and underlying mechanisms.

nmSCs infiltration was quantified in ESCC transcriptomic datasets from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) using single-sample gene set enrichment analysis (ssGSEA). Genes associated with nmSC infiltration were identified by weighted gene co-expression network analysis (WGCNA) and correlation analyses. Potential upstream regulators and signaling pathways were explored by pan-cancer analyses in the Tumor Immune Estimation Resource (TIMER) database. nmSCs infiltration and candidate regulator expression were validated in an independent surgical cohort by immunohistochemistry (IHC). In addition, to investigate the regulatory relationship between teashirt zinc finger homeobox 3 (TSHZ3) and neuregulin 1 (NRG1) and their effects on Schwann cells (SCs) function, a co-culture system of ESCC cells and SCs was established. Functional validation was performed by knocking down TSHZ3 in ESCC cells, followed by quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, and Cell Counting Kit-8 (CCK-8) assays. A postoperative prognostic model incorporating nmSC infiltration was subsequently developed.

Elevated nmSCs infiltration was significantly associated with poor survival in ESCC. IHC validation further confirmed nmSCs infiltration as an independent prognostic risk factor in patients undergoing surgical resection. Integrated analyses identified TSHZ3 as a potential upstream regulator of SCs infiltration, potentially acting through the NRG1 pathway in ESCC and multiple other tumor types. IHC demonstrated a significant positive correlation between TSHZ3 expression and nmSCs infiltration. Further in vitro functional experiments confirmed that knockdown of TSHZ3 in ESCC cells significantly reduced NRG1 expression levels and inhibited the proliferative capacity of SCs in the co-culture system, providing more direct evidence for the TSHZ3-NRG1 regulatory axis.

nmSCs infiltration predicts adverse prognosis in ESCC, and TSHZ3 may promote nmSCs infiltration via the NRG1 signaling axis.