Shikonin sensitises osimertinib-resistant lung adenocarcinoma to ferroptosis through HES1-mediated ATF3 upregulation
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Updated: Jul 10, 2026
Establishment and Characterization of Three Afatinib-resistant Lung Adenocarcinoma PC-9 Cell Lines Developed with Increasing Doses of Afatinib
Published on: June 26, 2019
Haiwen Li1,2,3,4, Quan Yang1,3,4, Li Yang1,2,3,4
1Department of Pulmonary Oncology, Affiliated Hospital of Guangdong Medical University, Zhanjiang 524000, China.
Abstract:
Acquired resistance to osimertinib poses a major challenge in treating EGFR-mutant lung adenocarcinoma (LUAD). Here, we demonstrate that shikonin, a natural compound from Lithospermum erythrorhizon, synergizes with osimertinib to overcome this resistance by inducing ferroptosis. In osimertinib-resistant LUAD cells (PC9-OR/H1975-OR), the shikonin-osimertinib combination significantly enhances cytotoxicity and suppresses proliferation while triggering ferroptotic events, including reactive oxygen species accumulation, lipid peroxidation, and iron overload alongside glutathione depletion. RNA-sequencing identifies Hes family BHLH transcription factor 1 (HES1) downregulation as crucial to this process. HES1 knockdown replicates the combination's effects, confirming its key role. Mechanistically, ATF3 is identified as a direct transcriptional target of HES1, with HES1 binding to the ATF3 promoter (-786 to -779 nt) to repress its transcription. The shikonin-osimertinib combination relieves this repression, leading to ATF3-mediated suppression of the ferroptosis regulators SLC7A11 and GPX4. In vivo, this combination potently inhibits tumor growth in xenograft models without observable toxicity. Our study reveals a novel HES1/ATF3 axis governing ferroptosis and proposes shikonin as a promising therapeutic adjuvant to overcome osimertinib resistance in LUAD.
Insights
Shikonin combined with osimertinib overcomes drug resistance in EGFR-mutant lung adenocarcinoma by inducing ferroptosis. This novel therapy targets the HES1/ATF3 pathway, offering a promising treatment strategy.
Area of Science:
- Oncology
- Molecular Biology
- Pharmacology
Background:
- Acquired resistance to osimertinib is a significant obstacle in treating EGFR-mutant lung adenocarcinoma (LUAD).
- Targeted therapies often face challenges due to the development of drug resistance.
- Identifying novel therapeutic strategies is crucial for improving patient outcomes.
Purpose of the Study:
- To investigate the potential of shikonin, a natural compound, in combination with osimertinib to overcome acquired resistance in EGFR-mutant LUAD.
- To elucidate the underlying molecular mechanisms, including the role of ferroptosis and specific gene pathways.
- To evaluate the efficacy and safety of the combination therapy in vivo.
Main Methods:
- Utilized osimertinib-resistant LUAD cell lines (PC9-OR/H1975-OR) for in vitro studies.
- Assessed cytotoxicity, proliferation, and ferroptotic markers (ROS, lipid peroxidation, iron, glutathione).
- Performed RNA-sequencing to identify key molecular players, followed by gene knockdown experiments and in vivo xenograft studies.
Main Results:
- The shikonin-osimertinib combination significantly enhanced cytotoxicity and suppressed proliferation in resistant LUAD cells.
- The treatment induced ferroptosis, characterized by increased reactive oxygen species, lipid peroxidation, iron overload, and glutathione depletion.
- Downregulation of Hes family BHLH transcription factor 1 (HES1) was identified as critical, leading to ATF3-mediated suppression of SLC7A11 and GPX4, key ferroptosis regulators.
Conclusions:
- Shikonin synergizes with osimertinib to induce ferroptosis and overcome resistance in EGFR-mutant LUAD.
- A novel HES1/ATF3 regulatory axis controlling ferroptosis was uncovered.
- Shikonin represents a promising therapeutic adjuvant for overcoming osimertinib resistance in LUAD, with potential for in vivo efficacy and safety.
