Aberrant expression of cancer testis antigens (CTAs) is reported in tumors, especially those with stemness properties. A number of CTAs can induce epithelial mesenchymal transition (EMT) process and promote cancer stem cells (CSCs) characteristics. We aimed in this study to analyze the correlation between NY-ESO1 and TWIST1 in esophageal squamous cell carcinoma (ESCC), as well as their impact on EMT process. Gene expression profiling of NY-ESO1 and TWIST1 was performed in 43 esophageal tumors compared to their margin normal tissues of using qRT-PCR, and their correlation with clinicopathological variables of the patients was evaluated. In silico analysis of the NY-ESO1, epithelial and mesenchymal cell markers and also their promoter sequences was executed. ESCC cell lines KYSE-30 and YM-1 were transduced to ectopically express TWIST1 using a retroviral system, followed by qRT-PCR mRNA expression analysis to reveal the probable correlation among TWIST1, NY-ESO1 and EMT markers gene expression. Scratch assay was performed to estimate migration of TWIST1-induced cells. Overexpression of TWIST1 and NY-ESO1 mRNA was observed in 42% and 39.5% (P ˂ 0.05) of tumors, respectively. Expression of the genes was significantly correlated with each other (p = 0.005). TWIST1 and NY-ESO1 overexpression was significantly associated with stage of progression and size of tumors, respectively. A direct association between TWIST1 and NY-ESO1 mRNA expression was confirmed by induced ectopic expression of TWIST1 in ESCC cell lines KYSE-30 and YM-1. TWIST1-induced cells led to increase migration in ESCC cell line. Furthermore, significant up-regulation of EMT markers was observed following ectopic expression of TWIST1 in these cells. Based on our findings, it may be proposed that a vital association is exist between the EMT and the acquisition of cancer stemness state in tumor cells through the TWIST1/NY-ESO1 axis and it can be a critical hallmark in ESCC tumorigenesis.

Keywords