Multigene Profiling of Circulating Tumor Cells in Esophageal Squamous Cell Carcinoma Identifies Prognostic Cancer Driver Genes Associated with Epithelial-Mesenchymal-Transition Progression and Chemoresistance

SIMPLE SUMMARY: Esophageal squamous cell carcinoma (ESCC) is a malignancy characterized by high mortality and dismal quality of life. Circulating tumor cells (CTCs), considered precursors of distant metastasis, can be analyzed using a non-invasive liquid biopsy approach to identify patients at risk of cancer progression or recurrence. The current study employed an unbiased size-based CTC enrichment strategy in combination with quantitative reverse transcription polymerase chain reaction (RT-qPCR) to investigate gene transcripts as potential biomarkers in the bloodstream. We categorized 83.6% (46/55) of ESCC patients as CTC-positive, each displaying at least two detected markers. Furthermore, 50.9% (28/55) of ESCC patients were identified as CTC-high, showing at least five detected markers using a 10-gene CTC panel. The presence of specific markers, namely TWIST1, VEGFC, CCND1, and TFRC, was significantly associated with shorter survival of the patients, suggesting their prognostic values as liquid biopsy markers to guide clinical ESCC treatment decisions and enhance treatment efficacy. ABSTRACT: We investigated the clinical significance of CTCs in cancer progression by detecting multiple cancer driver genes associated with epithelial-to-mesenchymal transition (EMT) at the transcript level. The 10-gene panel, comprising CCND1, ECT2, EpCAM, FSCN1, KRT5, KRT18, MET, TFRC, TWIST1, and VEGFC, was established for characterizing CTCs from mouse ESCC xenograft models and clinical ESCC peripheral blood (PB) samples. Correlations between gene expression in CTCs from PB samples (n = 77) and clinicopathological features in ESCC patients (n = 55) were examined. The presence of CTCs at baseline was significantly correlated with tumor size (p = 0.031). The CTC-high patients were significantly correlated with advanced cancer stages (p = 0.013) and distant metastasis (p = 0.029). High mRNA levels of TWIST1 (Hazard Ratio (HR) = 5.44, p = 0.007), VEGFC (HR = 6.67, p < 0.001), TFRC (HR = 2.63, p = 0.034), and EpCAM (HR = 2.53, p = 0.041) at baseline were significantly associated with a shorter overall survival (OS) in ESCC patients. This study also revealed that TWIST1 facilitates EMT and enhances malignant potential by promoting tumor migration, invasion, and cisplatin chemoresistance through the TWIST1-TGFBI-ZEB1 axis in ESCC, highlighting the prognostic and therapeutic potential of TWIST1 in clinical ESCC treatment.