EPHA5 enhances stemness and decreases gefitinib sensitivity via Wnt signaling pathway in non-small lung cancer

Abstract

Objective

Non-small lung cancer (NSCLC) is the most prevalent form of lung cancer, and it is often associated with poor patient outcomes. Erythropoietin-producing hepatocellular receptor A5 (EPHA5), a member of the Eph tyrosine kinase receptor family, has been implicated in various stages of tumor progression. However, the specific role of EPHA5 in NSCLC remains poorly understood. This study aims to explore the influence of EPHA5 on the stemness of NSCLC cancer cells and their sensitivity to gefitinib, while also investigating the underlying mechanisms involved.

Methods

EPHA5 expression was suppressed using small interfering ribonucleic acids (siRNAs), while qPCR and Western blot were applied to analyze the knockdown efficiency. Subsequently, the expressions of stem cell-related markers, such as SOX2, Nanog, KLF4, Oct4, and β-catenin, were detected and quantified via qPCR and Western blot during the experiment, while CD133-positive cells were analyzed via flow cytometry. Gefitinib sensitivity was evaluated in EPHA5-knockdown cells. The Wnt activator, CHIR-99021, was employed to rescue β-catenin expression.

Results

EPHA5 expression was elevated in NSCLC cell lines (NCI-H460 and NCI-H1229) but considerably downregulated by siRNAs. EPHA5 knockdown alleviated stemness, enhanced gefitinib sensitivity, and suppressed Wnt activation, as evidenced by lower CD133-positive cells, and decreased expression of Sox2, Nanog, KLF4, Oct4, and β-catenin. The Wnt activator reversed the inhibitory effect of EPHA5 on cancer cell stemness by upregulating β-catenin.

Conclusion

Silencing the expression of EPHA5 can reduce NSCLC stemness and enhance gefitinib sensitivity by inhibiting the Wnt signaling pathway.

Strengths and limitations of this study

We find EPHA5 enhances stemness and decreases gefitinib sensitivity via Wnt signaling pathway of non-small cell lung cancer but prognostic follow-up of lung adenocarcinoma patients in this study is lacking.