The expression of PTK7 in pancreatic ductal adenocarcinoma and its clinical significance / 中国肿瘤临床

ABSTRACT

Objective: To explore the expression of PTK7 in pancreatic ductal adenocarcinoma and its clinical significance. Methods: The clinical and follow-up data of 85 patients with pancreatic ductal adenocarcinoma who underwent radical surgery at Tianjin Medical University Cancer Institute and Hospital from May 2011 to January 2016 were analyzed. The expression of PTK7 in 85 pancreatic cancer tissues and the corresponding para-cancer tissues was detected by immunohistochemistry, and the relationship between PTK7 expression level and the clinical pathological features and prognosis was analyzed. Results: Positive expression of PTK7 was observed mainly in the cytoplasm, presenting as brownish yellow granules. It was noted that expression of PTK7 in pancreatic ductal adenocarcinoma tissues and para-carcinoma tissues was 70.6% (60/85) and 52.9% (45/85), respectively, and the positive rate in pancreatic ductal adenocarcinoma tissues was significantly higher than that in para-carcinoma tissues; the difference was statistically significant (P<0.05). The abnormal expression of PTK7 was correlated with the tumor stage, lymph node metastasis, and the vascular tumor embolus (P<0.05). The survival analysis suggested that the survival time or recurrence-free time of patients with PTK7 high expression in pancreatic duct adenocarcinoma was significantly shorter than in those with low expression (P<0.05, respectively). ShRNA interference of PTK7 was successfully established in the cell stabilizing system, verified by MTT and clone formation. Results indicated that cell survival was significantly lower in the shRNA experimental group compared to the control group (P<0.05), the number of colonies formed was significantly smaller in the shRNA experimental group compared to the control group (P<0.05), and the expression of proliferation-related proteins Ki-67 and PCNA was significantly lower in the shRNA experimental group compared to the control group (P<0.05, respectively). Conclusions: The up-regulation of PTK7 expression in pancreatic ductal ad-enocarcinoma tissues was associated with the tumor stage, lymph node metastasis, and the vascular tumor thrombus, suggesting poor prognosis. It was also found that in pancreatic cancer cell lines, PTK7 could promote the proliferation of pancreatic cancer cells by regulating the levels of proliferative factors Ki-67 and PCNA.