Clinical implications of insulin-like growth factor II mRNA-binding protein 3 expression in non-small cell lung carcinoma

In order to examine the role of insulin-like growth factor II mRNA-binding protein 3 (IMP3) expression for the prognostic evaluation of non-small cell lung carcinoma (NSCLC), a total of 186 breast cancer patients, with adjacent non-tumor lung tissues, were selected for immunohistochemical staining of IMP3 protein. The NSCLC tissues and paired adjacent non-tumor tissues of six patients were quantified using reverse transcription quantitative polymerase chain reaction. The correlations between IMP3 overexpression and the clinical features of NSCLC were evaluated using the χ2 test and Fisher's exact test. The survival rate was calculated using the Kaplan-Meier method, and the association between prognostic factors and patient survival was also analyzed by Cox's proportional hazards models. The results showed that IMP3 protein exhibited a mainly cytoplasmic staining pattern in the NSCLC tissues. The positive rate of IMP3 protein expression was 74.7% (139/186) in the NSCLC tissues and was significantly higher than the rate of 19.9% (37/186) in the adjacent non-tumor tissues. The expression rate of the NQO1 protein was correlated with a large tumor size, poor differentiation, lymph node metastasis, late clinical stage, and disease-free and overall survival rates in the NSCLC patients. In the early- and late-stage NSCLC groups, the disease-free and overall survival rates of the patients with IMP3 expression were significantly lower than those of the patients without IMP3 expression. Further analysis using Cox's proportional hazard regression model revealed that IMP3 expression was a significant independent hazard factor for the overall survival rate of patients with NSCLC. In conclusion, the present study found that IMP3 plays a significant role in the progression of NSCLC, and that it may potentially be used as an independent biomarker for prognostic evaluation of the cancer.