Abstract:

Objective To investigate the expression level of Septin 9 isoform 1（SEPT9_i1）and promyelocytic leukaemia zinc finger（PLZF）protein in gastric cancer tissues， and to analyze the relations between them with the clinical pathological features and prognosis of gastric cancer. Methods The immunohistochemistry EnVision two step method was used to detect the SEPT9_i1 and PLZF expression in paraffin embedded 75 cases of gastric cancer tissues and 62 cases of paracancerous tissue. The staining Results of the tumors were expressed as the product of the staining intensity and the percentage of positive tumor cells. The expression was divided into high expression group（＜5）and low expression group（≥5）. We analyzed the correlation between tumor tissue expression and clinical parameters， such as gender， age， clinical stage， tumor location， Lauren typing， tumor size， differentiation， depth of invasion and lymph node metastasis. Moreover， the correlation between tumor tissue expression and prognosis were also analyzed. The Spearman correlation analysis was used to analyze the expression of PLZF and SEPT9_i1 in gastric cancer tissues. Results The higher expression of SEPT9_i1 in gastric cancer tissues was higher than that in para-carcinoma tissues（65.33％ vs. 37.10％， P＜0.05）， and the PLZF expression was lower than that in para-carcinoma tissues（41.33％ vs. 85.48％， P＜0.05）. There was negative correlation between expression of SEPT9_i1 and PLZF in gastric cancer tissues（P=0.009， r=-0.299）. The expression of both proteins was related to clinical stage and lymph node metastasis. Expression of SEPT9_i1 was related to the depth of invasion， and the expression of PLZF was related to the differentiation degree（P＜0.05）. The median overall survival（OS）was 21.5 months in patients with high expression of SEPT9_i1， lower than 32.0 months of patients with low expression of SEPT9_i1（P＜0.05）. The median OS was 26.5 months in patients with high expression of PLZF， similar to 31.0 months in patients with low expression of PLZF（P＞0.05）. Conclusion SEPT9_i1 was highly expressed in gastric cancer tissues but PLZF was low expression. Both were related to clinical stage and lymph node metastasis, and SEPT9_i1 expression is related to the prognosis of gastric cancer patients，suggesting that they may play an important role in the occurrence and development of gastric cancer，and can be used in the diagnosis and evaluation of gastric cancer.