Curcumol Inhibits the Laminin-Facilitated Malignant Progression in Small-Cell Lung Cancer via Disrupting Laminin-Integrin β1 Interaction.

Abstract

Laminin promotes tumor progression, but its role in small-cell lung cancer (SCLC) remains unclear. Curcumol, a natural compound from Curcumae Rhizoma, has anti-tumor activity. Here, we tested the hypothesis that Curcumol disrupts Laminin-Integrin β1 interaction to suppress SCLC. SBC-2 and H69 cells were cultured on Laminin-coated substrates. Cell functions were assessed by Transwell migration, colony formation, and MTT assays. Molecular mechanisms were investigated through qRT-PCR, Western blot, molecular docking, Co-IP, and Dot blot assays. Target specificity was confirmed by Integrin β1 mutagenesis. The therapeutic efficacy of Curcumol was evaluated in xenograft mouse models. Laminin enhanced malignant phenotypes in SCLC cells, accompanied by the activation of FAK/ERK and TGF-β/Smad2/3 pathways. Curcumol inhibited the laminin-promoted malignant phenotypes and epithelial-mesenchymal transition (EMT) in SCLC cells and suppressed the expression of related proteins. Mechanistic studies revealed that Curcumol directly bound to Integrin β1, competitively inhibiting the binding of Laminin to Integrin β1 and the activation of downstream signaling. Target specificity was validated through mutagenesis studies, where Curcumol exhibited reduced efficacy in Integrin β1-mutant cells. In vivo, Curcumol (100 mg/kg, oral) attenuated Laminin-driven tumor growth, suppressed EMT and FAK/ERK signaling, with no detectable toxicity. Integrin β1 is a key mediator of Laminin's pro-tumorigenic effects in SCLC. Curcumol disrupts Laminin-Integrin β1 interaction, inhibits FAK/ERK signaling and EMT, and suppresses tumor progression, representing a promising therapeutic strategy.