ATPase inhibitory factor 1 expression is an independent prognostic factor in non-small cell lung cancer

ATPase inhibitory factor 1 (IF1), an inhibitor of the mitochondrial H(+)-adenosine triphosphate (ATP) synthase, is putatively involved in tumor progression. This study aimed to evaluate the expression levels of IF1 in non-small cell lung cancer (NSCLC) and the prognostic value for the patients. IF1 protein expression levels were detected in 149 cases of NSCLC by using immunohistochemistry. Kaplan-Meier analysis showed that NSCLC patients with high expression of IF1 possessed poorer outcome than those with low expression of IF1 (P=0.007). Moreover, IF1 was also prognostic in the patients with early stages (stage I/II) (P=0.042) and low grade (grade I/II) (P=0.002). Multivariable Cox-regression analysis showed that high expression of IF1 (HR=1.67, P=0.034), tumor size (HR=1.79, P=0.001), and lymph node metastasis (HR=2.66, P=0.000) were independent indicators for NSCLC patients. In conclusion, our study demonstrated that elevated expression of IF1 may associated with lymph node metastasis of NSCLC and served as an independent prognostic and recurrent indicator for the patients.