The expression and clinical significance of stem cell transcription factor SOX2, OCT4 in gastric ;cancer tissues varying degrees of cell differentiation / 中国癌症杂志

ABSTRACT

Background and purpose:Differentiation of tumor tissue is an important factor on determining the prognosis of gastric cancer. This study aimed to investigate the expression levels and clinical signiifcance of gender determining region Y-box 2 (SOX2) gene and octamer binding factor 4 (OCT4) gene in gastric cancer tissues varying different differentiation degrees. Methods: Sixty cases with gastric cancer were recruited in this study. The gastric cancer tissues and corresponding normal mucosa of the 60 cases were obtained. The mRNA and protein level of SOX2, OCT4 gene are evaluated by the quantitative real-time PCR (qRT-PCR), Western blot and immunohistochemistry, respectively. The relationship between the expression levels of SOX2, OCT4 gene and clinical pathological parameters were also analyzed in this study. Results:The expression of SOX2 in both mRNA and protein levels had no signiifcant difference between the well-differentiated gastric cancer tissues and normal gastric mucosa (mRNA levelst=0.1033, P>0.05;protein levelst=0.116, P>0.05). However, both the mRNA and protein expression of SOX2 in patients with well-differentiated gastric cancer tissues were signiifcant higher than not only in patients with moderately differentiated gastric carcinoma (mRNA levels t=12.48, P0.05;protein levelst=1.064, P>0.05). Immunohistochemical study demonstrated that the positive rate of SOX2 in patients with well-differentiated gastric cancer tissues (10/21) were higher than in patients with not only moderately differentiated gastric carcinoma (7/20) but also poorly differentiated gastric carcinoma (2/19, P0.05). Nevertheless, the expression of SOX2, OCT4 were positive or negative correlated with the pathological staging, the degree of inifltration and lymph node metastasis (P<0.05). Conclusion:Decreased SOX2 expression and increased expression level of OCT4 can promote the formation, development and invasion of gastric cancer and they may become biomarkers or the diagnosis, treatment and prognosis evaluation in gastric carcinoma.