4-O-Demethylbarbatic acid has a novel therapeutic impact on the progression of EGFR-driven lung adenocarcinoma

Abstract

Background: 4-O-Demethylbarbatic acid (4O-DBA), a secondary metabolite derived from lichen species, has shown inhibitory activity of epstein-barr virus (EBV), indicating its potential in cancer prevention or treatment. However, the mechanisms underlying its anti-cancer effects, particularly in non-small cell lung cancer (NSCLC), remain unclear.

Purpose: We investigated the anti-cancer activity of 4O-DBA-driven EGFR inhibition on cancer metastasis and tumorigenicity of NSCLC cells A549 (EGFR-wild type), H1975 (L858R mutant), PC9 (EGFR exon 19 deletion) and PC9/GR (gefitinib resistant) cells.

Methods: The novel impact of 4O-DBA on cell survival, metastasis and oncogenic progression were evaluated by MTT assay, trans well invasion, colony formation assay, immunoblotting, quantitative PCR-based assessment, cell cycle measurement in vitro; pharmacological network analysis and molecular interaction modeling were utilized to identify the potential targets and pathways of 4O-DBA in NSCLC. Additionally, an in vivo tumorigenicity study was conducted using the LLC/iRFP trachea inoculation and xenograft mouse model.

Results: 4O-DBA potently decreased invasion, proliferation, and tumorigenesis of NSCLC cells in vitro and demonstrated efficacy in vivo. A key novel finding was that network pharmacology analysis indicated that 4O-DBA exhibits a strong binding affinity for EGFR, particularly the L858R mutant. By inhibiting EGFR, 4O-DBA suppressed AKT activation and downregulated key transcriptional regulators associated with cancer metastasis and tumorigenesis, including NF-κB, β-catenin, MMP-9, and Twist. 4O-DBA overcomes gefitinib resistance by suppressing key EGFR signaling pathways, reducing cancer progression, and reversing resistance-associated molecular markers. A significant insightful finding in our study is that 4O-DBA was shown to synergize with gefitinib and sorafenib, enhancing their efficacy in suppressing cell proliferation and viability.

Conclusion: This work sheds new light on the anti-cancer mechanisms of 4O-DBA in NSCLC, particularly its ability to inhibit EGFR-mutated NSCLC by targeting key oncogenic pathways. Our findings suggest that 4O-DBA could offer a promising new treatment strategy for overcoming EGFR resistance in lung cancer.

Keywords: 4-O-Demethylbarbatic acid; EGFR resistance; Lichen secondary metabolites; Lung cancer; Receptor tyrosine kinase therapy.