Elevated expression of SHIP2 correlates with poor prognosis in non-small cell lung cancer

SH2-containing inositol 5'-phosphatase 2 (SHIP2) is a vital regulator of phosphoinositide pools in metabolic pathways and is considered to downregulate phosphatidylinositol 3'-kinase signaling, which underlies the development of several kinds of human cancers. However, SHIP2 expression in non-small cell lung cancer (NSCLC) and its relationship with the clinical characteristics of NSCLC remain poorly understood. In this study, one-step quantitative reverse transcription-polymerase chain reaction and immunohistochemistry analysis with tissue microarray was used to evaluate SHIP2 expression in NSCLC and to investigate the relationship of this expression to NSCLC prognosis. Results showed that the expression of SHIP2 messenger RNA and protein was significantly higher in NSCLC than in corresponding non-cancerous tissues (both p < 0.05). SHIP2 protein expression in NSCLC was related to lymph node metastasis (p = 0.042), TNM stage (p = 0.036), and 5-year survival rate (p = 0.046). The Kaplan-Meier method and log-rank test suggested that high SHIP2 expression, tobacco consumption, and advanced tumor stage were significantly associated with low survival of NSCLC patients. The results of this research suggested that SHIP2 expression was correlated with malignant phenotypes of NSCLC and may thus serve as a poor prognostic factor and valuable oncogene for NSCLC.