SOX2/SALL4 stemness axis modulates Notch signaling genes to maintain self-renewal capacity of esophageal squamous cell carcinoma.

Stemness phenotype is considered as the centerpiece of cancer biology due to its potential in conventional chemo-radiotherapy resistance and tumor recurrence after clinical intervention. This feature in tumor mass belongs to activation of core regulatory stemness factors and different cell signaling pathways in cancer stem cells. We aimed in this study to elucidate contribution of Notch signaling pathway in stemness state of esophageal squamous cell carcinoma (ESCC) through their relevance with stem cell markers SOX2 and SALL4. 50 ESCC tumor and related margin normal tissues were considered and categorized based on SOX2/SALL4 expression pattern, and mRNA levels of Notch signaling genes including ligands, receptors, target genes, and transcriptional coactivator were analyzed in the selected groups using qRT-PCR. Concomitant overexpression of stem cell markers SOX2 and SALL4 in ESCCs upregulated the involved genes in Notch signaling pathway. Upregulation of Notch pathway genes associated with depth of tumor invasion and lymph node metastasis of ESCC. Based on biological function of SOX2 and SALL4 axis in stemness state potential, our results may suggest contribution of Notch signaling pathway in self-renewal capacity of ESCCs, as well as invasion and metastasis of the disease. To the best of our knowledge, this is the first report elucidating the crosstalk between SOX2/SALL4 stemness factors and Notch signaling pathway in cancer research.