Altingia chinensis petroleum ether extract suppresses NSCLC via induction of apoptosis, attenuation of EMT, and downregulation of PI3K/Akt pathway.

Background: Non-small-cell lung cancer (NSCLC) is the primary type of lung cancer with the leading cause of fatalities from cancer, and the effective treatment is minimal. Altingia chinensis is a medicinal plant utilized as a traditional folk remedy to alleviate rheumatism, punch injury and paralysis. APE is the petroleum ether extract from A. Chinensis, whose antitumor effects are rarely studied.

Purpose: To explore the antitumor effects of APE on NSCLC and its molecular mechanism.

Methods: LLC and H1299 cells were used to explore the anticancer effect of APE on NSCLC in vitro. MTT assay and colony formation were employed to evaluate cell viability. Flow cytometry was used to evaluate apoptosis. Wound healing and transwell were employed to evaluate cell migration and invasive capacity. Meanwhile, an LLC tumor-bearing C57BL/6J mice model was established for assessing the anticancer effect of APE on NSCLC in vivo. H&E staining was used to assess histopathology. TUNEL assay was performed to assess apoptosis in tumor tissue. Network pharmacology, CESTA, and kinase assay were employed to analyze potential molecular mechanisms. Western blots were performed to detect proteins involved in apoptosis, EMT, and the PI3K/Akt pathway.

Results: This is the first investigation to identify APE's antitumor potential in both NSCLC cells and tumor-bearing mice models. Significantly, APE dose-dependently decreased cell viability and caused morphological changes both in LLC and H1299 cells. Furthermore, APE (31.25, 62.5, and 125 μg/ml) induced apoptosis in NSCLC cells, as demonstrated by increased Annexin V-FITC/PI-stained cells, the cleaved-caspase 3 levels, and the Bax/Bcl-2 ratio. Additionally, APE suppressed cell migration and invasion by the increase of E-cadherin expression and the downregulation of vimentin, implying that APE inhibited cell metastasis via attenuation of EMT. Importantly, intragastric administration of 100 mg/kg APE significantly inhibited tumor growth without apparent side effects. TUNEL assay confirmed the apoptosis in tumor tissue. Western blots validated the alteration of EMT and apoptotic markers in tumor tissue, which matched the in vitro findings. Moreover, APE directly bound to PI3Kα and inhibited its activity, leading to inhibition of the PI3K-Akt pathway.

Conclusion: Overall, APE exhibits anti-tumor effects on NSCLC via induction of apoptosis, attenuation of EMT, and its mechanism involves the suppression of the PI3K/Akt pathway. Our study offers new insights for the identification of novel drug development for NSCLC.