Monocarboxylate transporter 1 is an independent prognostic factor in esophageal squamous cell carcinoma.

The monocarboxylate transporter 1 (MCT1) has been reported to have significant prognostic value in several solid tumors. The present study aimed to explore its clinical significance in esophageal squamous cell carcinoma (ESCC). After acquiring and analyzing MCT1 (solute carrier family 16 member; SLC16A1) mRNA expression in The Cancer Genome Atlas (TCGA) database, the prognostic potential of MCT1 was assessed by immunohistochemistry (IHC). The impact of the knockdown of MCT1 by shRNA was evaluated using Cell Counting Kit‑8 (CCK‑8) and colony formation assays to determine whether MCT1 suppression affected the proliferation and survival of ESCC cells. MCT1 expression was found to correlate with T stage (P=0.005), N stage (P=0.036) and TNM stage (P=0.035). Kaplan‑Meier survival analysis showed that patients in a high‑MCT1 group had a lower overall survival (OS) (P<0.001) and lower progression‑free survival (PFS) (P<0.001). The results of univariate and multivariate Cox regression analyses demonstrated that MCT1 is an independent prognostic factor for OS (P=0.001 and 0.01) and PFS (P=0.001 and 0.012). Downregulation of MCT1 suppressed proliferation and survival of ESCC cells in vitro. The proliferation rate and colony numbers were decreased in the sh‑MCT1 groups (all P<0.05). Downregulation of MCT1 suppressed VEGF expression (all P<0.05). MCT1 may act as a biomarker for ESCC to identify patients with poor outcomes.