Cucurbitacin B inhibits TGF-β1-induced epithelial-mesenchymal transition (EMT) in NSCLC through regulating ROS and PI3K/Akt/mTOR pathways
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Updated: Oct 3, 2025
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Published on: October 27, 2020
Renyikun Yuan1,2, Qiumei Fan2, Xiaowei Liang2
1College of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, China.
Background:
Lung cancer is the leading cause of cancer mortality worldwide, and most of the patients after treatment with EGF-TKIs develop drug resistance, which is closely correlated with EMT. Cucurbitacin B (CuB) is a natural product of the Chinese herb Cucurbitaceae plant, which has a favorable role in anti-inflammation and anti-cancer activities. However, the effect of CuB on EMT is still far from fully explored. In this study, the inhibition effect of CuB on EMT was investigated.
Methods:
In this study, TGF-β1 was used to induce EMT in A549 cells. MTS assay was used to detect the cell viability of CuB co-treated with TGF-β1. Wound healing assay and transwell assay were used to determine the migration and invasion capacity of cells. Flow cytometry and fluorescence microscope were used to detect the ROS level in cells. Western blotting assay and immunofluorescence assay were used to detect the proteins expression. Gefitinib was used to establish EGF-TKI resistant NSCLC cells. B16-F10 intravenous injection mice model was used to evaluate the effect of CuB on lung cancer metastasis in vivo. Caliper IVIS Lumina and HE staining were used to detect the lung cancer metastasis of mice.
Results:
In this study, the results indicated that CuB inhibited TGF-β1-induced EMT in A549 cells through reversing the cell morphology changes of EMT, increasing the protein expression of E-cadherin, decreasing the proteins expression of N-cadherin and Vimentin, suppressing the migration and invasion ability. CuB also decreased the ROS production and p-PI3K, p-Akt and p-mTOR expression in TGF-β1-induced EMT in A549 cells. Furthermore, Gefitinib resistant A549 cells (A549-GR) were well established, which has the EMT characteristics, and CuB could inhibit the EMT in A549-GR cells through ROS and PI3K/Akt/mTOR pathways. In vivo study showed that CuB inhibited the lung cancer metastasis effectively through intratracheal administration.
Conclusion:
CuB inhibits EMT in TGF-β1-induced A549 cells and Gefitinib resistant A549 cells through decreasing ROS production and PI3K/Akt/mTOR signaling pathway. In vivo study validated that CuB inhibits lung cancer metastasis in mice. The study may be supporting CuB as a promising therapeutic agent for NSCLC and Gefitinib resistant NSCLC.
Insights
Cucurbitacin B (CuB) inhibits epithelial-mesenchymal transition (EMT) and lung cancer metastasis by reducing reactive oxygen species (ROS) and the PI3K/Akt/mTOR pathway. This natural compound shows promise for treating non-small cell lung cancer (NSCLC) and drug-resistant NSCLC.
Area of Science:
- Oncology
- Molecular Biology
- Pharmacology
Background:
- Lung cancer is a leading cause of cancer mortality globally.
- Acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGF-TKIs) is a major challenge in NSCLC treatment.
- Epithelial-mesenchymal transition (EMT) is closely linked to drug resistance and metastasis in lung cancer.
Purpose of the Study:
- To investigate the inhibitory effect of Cucurbitacin B (CuB) on EMT.
- To explore the underlying molecular mechanisms of CuB's action on EMT.
- To evaluate the efficacy of CuB in inhibiting lung cancer metastasis in vivo.
Main Methods:
- TGF-β1 was used to induce EMT in A549 lung cancer cells.
- Cell viability, migration, invasion, and ROS levels were assessed.
- Protein expression related to EMT and signaling pathways (PI3K/Akt/mTOR) was analyzed via Western blotting and immunofluorescence.
- Gefitinib-resistant NSCLC cells (A549-GR) were established.
- In vivo metastasis was evaluated in a B16-F10 melanoma lung metastasis mouse model.
Main Results:
- CuB reversed TGF-β1-induced EMT in A549 cells, increasing E-cadherin and decreasing N-cadherin and Vimentin expression.
- CuB suppressed cell migration and invasion, and reduced ROS production.
- CuB inhibited EMT in Gefitinib-resistant A549 cells by modulating ROS and the PI3K/Akt/mTOR pathway.
- In vivo studies demonstrated that CuB effectively inhibited lung cancer metastasis.
Conclusions:
- CuB inhibits EMT and lung cancer metastasis by decreasing ROS production and the PI3K/Akt/mTOR signaling pathway.
- CuB demonstrates potential as a therapeutic agent for both NSCLC and Gefitinib-resistant NSCLC.
- CuB represents a promising natural compound for NSCLC treatment, particularly in overcoming drug resistance and metastasis.
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