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

Wenmei Su; Liang Luo; Fenping Wu; Zhennan Lai; Xiaofang Li; Zhong Xie; Zhixiong Yang

Wenmei Su Department of Oncology, Affiliated Hospital of Guangdong Medical College, Zhanjiang ‑ 524 023, Guangdong, China.
Liang Luo Department of Oncology, Affiliated Hospital of Guangdong Medical College, Zhanjiang ‑ 524 023, Guangdong, China.
Fenping Wu Department of Radiotherapy, The Tumor Hospital of Chengdu, The Seventh People‘s Hospital of Chendu, Sichuan, China
Zhennan Lai Department of Oncology, Affiliated Hospital of Guangdong Medical College, Zhanjiang ‑ 524 023, Guangdong, China.
Xiaofang Li Department of Oncology, Affiliated Hospital of Guangdong Medical College, Zhanjiang ‑ 524 023, Guangdong, China.
Zhong Xie Department of Oncology, Affiliated Hospital of Guangdong Medical College, Zhanjiang ‑ 524 023, Guangdong, China.
Zhixiong Yang Department of Oncology, Affiliated Hospital of Guangdong Medical College, Zhanjiang ‑ 524 023, Guangdong, China.

Keywords: Immunohistochemistry, Non‑small cell lung cancer, Olfactomedin 4, Quantitative real‑time polymerase chain reaction

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.