GEOapplication/xmlftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE313nnn/GSE313389/primaryOK200TranscriptomicsHomo sapiensExpression profiling by high throughput sequencinghttps://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE313389GEOGSEfalseSingle-cell transcriptomic analysis reveals tumor-immune determinants of lymph node colonization and progression in thyroid cancerLymph node (LN) metastases are a major driver of mortality across solid cancers, including thyroid carcinomas, which are known for high rates of nodal colonization. To elucidate the determinants of nodal spread, we isolated tumor-infiltrating leukocytes from primary thyroid tumors and matched metastatic LNs for single-cell RNA sequencing with validation by multiplex immunohistochemistry. Comparing the microenvironmental alterations between primary tumors and their LNs, we found that thyrocytes and tumor-associated macrophages downregulate the expression of multiple inflammatory cytokine receptors, including TNFRSF12A and CX3CR1, upon LN colonization. LNs were associated with the induction of regulatory T cells to suppress T cell-mediated cytotoxicity compared to matched primary tumors. Notably, tumor-infiltrating lymphocytes within LNs demonstrated increased expression of activation markers, including interleukin-7 receptor (IL7R). High LN expression of IL7R was significantly correlated with improved outcomes and can serve as a biomarker in this heterogeneous disease. Our findings on the dynamic equilibrium within LN metastases may offer conserved mechanisms for nodal colonization across solid tumors.2026/06/19GSE313389GSM9367331GSM9367330GSM9367333GSM9367332GSM9367328GSM9367327GSM9367329GSM9367324GSM9367326GSM936732524676313389Homo sapiens