Background: The prognosis for esophageal squamous cell carcinoma (ESCC) patients with lymph node metastasis (LNM) is still dismal. Elucidation of the LNM associated genomic alteration and underlying molecular mechanisms may provide clinical therapeutic strategies for ESCC treatment.
Methods: Joint analysis of ESCC sequencing data were conducted to comprehensively survey SCNAs and identify driver genes which significantly associated with LNM. The roles of miR-548k in lymphangiogensis and lymphatic metastasis were validated both in vitro and in vivo. ESCC tissue and blood samples were analyzed for association between miR-548k expression and patient clinicopathological features and prognosis and diagnosis.
Results: In the pooled cohort of 314 ESCC patients, we found 76 significant focused regions including 43 amplifications and 33 deletions. Clinical implication analysis revealed a panel of genes associated with LNM with the most frequently amplified gene being MIR548K harbored in the 11q13.3 amplicon. Overexpression of miR-548k remarkably promotes lymphangiogenesis and lymphatic metastasis in vitro and in vivo. Furthermore, we demonstrated that miR-548k modulating the tumor microenvironment by promoting VEGFC secretion and stimulating lymphangiogenesis through ADAMTS1/VEGFC/VEGFR3 pathways, while promoting metastasis by regulating KLF10/EGFR axis. Importantly, we found that serum miR-548k and VEGFC of early stage ESCC patients were significantly higher than that in healthy donators, suggesting a promising application of miR-548k and VEGFC as biomarkers in early diagnosis of ESCC.
Conclusions: Our study comprehensively characterized SCNAs in ESCC and highlighted the crucial role of miR-548k in promoting lymphatic metastasis, which might be employed as a new diagnostic and prognostic marker for ESCC.
Keywords: Esophageal squamous cell carcinoma; Lymphangiogenesis. Tumor microenvironment miR-548k; Lymphatic metastasis.