Downregulation of olfactomedin 4 expression contributes to tumorigenesis of non-small cell lung cancer

Abstract

Background and Aim: Olfactomedin 4 (OLFM4), a member of the ‘sense of smell’ mediated olfactomedin-related protein family, confers resistance to glycoprotein apoptosis. This study aims to examine the correlation between OLFM4 expression and clinicopathologic data in non-small cell lung cancer (NSCLC), including the prognosis of patients. Methods: Ninety-eight NSCLC patients from 2001 to 2013 were included in the study. OLFM4 expression was compared between lung cancer tissues and adjacent non-tumor tissues. In total, 98 and 27 specimens were used for immunohistochemistry (IHC) and quantitative real-time polymerase chain reaction (RT-PCR), respectively. The association of OLFM4 with clinicopathological parameters was evaluated using Pearson’s correlation. Overall survival (OS) was evaluated by Kaplan–Meier survival analysis. Results: IHC and RT-PCR analyses demonstrated low expression of OLFM4 in the cancer tissues (P < 0.05). High OLFM4 expression was positively correlated with peritumor intravascular cancer emboli (P = 0.013) but not associated with other clinical features, such as age, gender, tumor size, NSCLC subtype, or lymph node status (P > 0.05). Kaplan–Meier survival curves showed that the OS rate was not significantly associated with OLFM4 expression (P = 0.927). Conclusion: High OLFM4 expression could be a potential protective factor but not a prognostic factor for the tumorigenesis of NSCLC.