SOX1 is correlated to stemness state regulator SALL4 through progression and invasiveness of esophageal squamous cell carcinoma

SOX1, as a tumor suppressor, play anti-tumorigenecity role in different cells and its expression is inhibited in a variety of cancers. The aim of this study was to evaluate SOX1 expression and its correlation with cancer stem cell (CSC) markers in ESCC. Using real time PCR, the relative comparative expression of SOX1 in 40 ESCC samples was assessed compared to related margin normal tissues, and its correlation with CSC markers including SALL4, SOX2, and MEIS1 was analyzed statistically. The results revealed significant under-expression of SOX1 in ESCC in significant correlation with different indices of poor prognosis including depth of tumor invasion (P = 0.02), Stage of tumor cell progression (P = 0.05), and number of involved lymph node metastasis (P = 0.05). Furthermore, the under-expression of SOX1 was associated significantly with SALL4 overexpression. This study was the first to evaluate SOX1 underexpression and its association with poor prognosis in ESCC. Since correlation of SOX1 and SALL4 was detected in advanced stages of ESCC progression, as well as high invasive and aggressive tumor tissues, it may be extrapolated that SOX1 expression may have critical role in inhibition of ESCC invasiveness and aggressiveness especially in advanced stages of the disease.