Targeting Neuregulin 1 (NRG1): A Novel Biomarker for Non-Small-Cell Lung Cancer

The aim of this study was to identify the roles of neuregulin 1 (NRG1) during the tumor progression in non-small-cell lung cancer (NSCLC). NSCLC patients with lung squamous cell carcinoma and lung adenocarci-noma were enrolled in this study. The expression of NRG1, vascular endothelial growth factor (VEGF) and surviving in clinical specimens was examined using immunohistochemistry analysis. The cytokine production in plasma was evaluated by ELISA. The levels of NRG1-associated molecules were determined using western blotting. The proliferation and apoptosis of cells with NRG1 knockdown were accessed by CCK-8 assay and flow cytometry. Upregulation of NRG1 as well as tumor-associated angiogenesis markers VEGF and survivin was detected in tissue and serum samples of NSCLC patients compared with the control. Furthermore, positive correlation with NSCLC levels and VEGF/survivin was also found in NSCLC specimens. In addition, upregulation of NRG1, VEGF and survivin was associated with poor overall survival in NSCLC patients. Moreover, enhanced production of NRG1 was detected in serum samples from NSCLC patients compared with healthy donors, and ROC analysis revealed the importance of NRG1 levels on distinguishing NSCLC samples and the controls. These findings suggested the novel diagnostic value of NRG1 in NSCLC. Additionally, upregulated protein levels of NRG1 and its target genes were also found in tissues samples of NSCLC patients compared with normal controls. These data indicated that NRG1 was a promising marker NSCLC, and it could be involved in tumor progression by targeting its downstream target including ErbB-Akt axis. Furthermore, the growth of lung cancer cells was suppressed by the knockdown of NRG1. Our findings could provide guidance for more accurate diagnosis for NSCLC, and future therapeutic approaches might be developed by better understanding of NRG-1-modulated molecular mechanisms during the tumor development in NSCLC.