Expression of INPP4B in gastric cancer and its clinical significance / 肿瘤研究与临床

ABSTRACT

Objective To investigate the expression of INPP4B in gastric cancer and its relationship with clinicopathological features and prognosis. Methods The expressions of INPP4B mRNA in fresh cancer tissues of 36 patients with gastric cancer and the paracancerous normal gastric mucosa tissues in the Affiliated Cancer Hospital of Shanxi Medical University between July 2014 and December 2014 were detected by using real-time quantitative polymerase chain reaction (RT-qPCR). The expressions of INPP4B protein and its downstream molecule phosphorylation AKT (p-AKT) in paraffin-embedded tumor tissues and the corresponding margin tissues of 49 gastric cancer patients between January 2010 and December 2010 were detected by using immunohistochemistry. The relationship between the expression of INPP4B and clinicopathological features and prognosis was analyzed. Results RT-qPCR results showed that the expression level of INPP4B mRNA was 0.21 ±0.04 compared with adjacent cancer normal tissues (t= -2.208, P< 0.05). Immunohistochemistry showed that INPP4B protein was highly expressed in normal margin tissues and lowly expressed in tumor tissues. There was a statistical difference in the positive intensity score between the two groups (u=4.70, P<0.01). However, p-AKT protein was overexpressed in tumor tissues and underexpressed in normal margin tissues. There was a statistical difference in the positive intensity score between the two groups (u=5.77, P<0.01). The expression of INPP4B and p-AKT protein was negatively correlated (r= -0.644, P< 0.01). The positive expression rate of INPP4B protein in gastric cancer patients was 34.7％ (17/49). There were no statistical differences of the positive expression rate of INPP4B protein in gender, age, pathological type, depth of invasion and lymph node metastasis (all P > 0.05). The median overall survival time of patients with INPP4B negative expression was 47 months, and that of patients with INPP4B positive expression was 48 months, and there was no statistical difference (P> 0.05). Conclusion The expression of INPP4B in gastric cancer tissue is low, which may play a role of tumor suppressor in the occurrence and development of gastric cancer by affecting the activity of AKT.