Analysis of the Gene Expression Profiling Interactive Analysis (GEPIA) database revealed that Kelch-like 17 (KLHL17) is overexpressed in
non-small cell lung cancer (NSCLC) including
adenocarcinoma (ADC) and
squamous cell carcinoma (SCC). We therefore explored the role of KLHL17 in the development and progression of NSCLC. Immunohistochemistry and western blotting showed that KLHL17 expression was significantly higher in the
tumor tissues from 173 patients with NSCLC, compared with the corresponding non-neoplastic tissue. In addition, upregulated KLHL17 expression was positively correlated with
tumor size,
lymph node metastasis and
tumor node
metastasis (TNM) stage, and affected the overall survival (OS) of patients with NSCLC. Consistent with clinical samples, in vitro studies demonstrated that KLHL17 expression was higher in various cell lines of NSCLC (A549, H1299, H460 and SK cells) as compared to normal human bronchial epithelial cells (HBE cells). Overexpression of KLHL17 in the cell lines of NSCLC with KLHL17-Flag plasmid promoted the proliferation and migration of
tumor cells, which was associated with elevated activation of Rat
sarcoma/
Mitogen-activated protein kinases (Ras/MAPK) signaling and increased expression of
cyclin D1,
cyclin D-dependent
kinases 4 (CDK4),
matrix metalloproteinase 2 (MMP2) and Ras homolog gene family member A (RhoA). In contrast, knockdown of KLHL17 in the cell lines of NSCLC using KLHL17
small interfering RNA suppressed the proliferation and migration of
tumor cells, in association with reduced activation of Ras/MAPK signaling and decreased expression of
cyclin D1, CDK4, MMP2 and RhoA. Moreover, treatment of
tumor cells with Ras inhibitor
salirasib prevented KLHL17-induced Ras/MAPK activity as well as
tumor proliferation and migration. These results suggest that upregulated KLHL17 in NSCLC promotes the proliferation and migration of
tumor by activating Ras/MAPK signaling pathway. Therefore, KLHL17 may be a novel therapeutic target for the treatment of NSCLC.