Boehmenan, a lignan from the Chinese medicinal plant Clematis armandii, induces apoptosis in lung cancer cells through modulation of EGF-dependent pathways.

ABSTRACT

BACKGROUND: Epidermal growth factor receptor (EGFR) is an effective molecular target for cancer treatment. Boehmenan, a lignan from the dried stems of Clematis armandii, exhibited the potent cytotoxic effects against many cancer cell lines in previous studies. However, the effects and underlying mechanism of boehmenan on non-small cell lung cancer (NSCLC) remains unclear. PURPOSE: The present study was designed to determine the in vitro anti-cancer properties and underlying molecular mechanisms of boehmenan on A549 NSCLC cells. STUDY DESIGN/METHODS: Cellular viability and chemoattractive properties of macrophages were investigated by using MTT and transwell migration assay, respectively. Mitochondrial membrane potential (ΔΨm), apoptotic ratio, and cell cycle were measured by flow cytometry. Protein expression was visualized by Western blot using specific antibodies. RESULTS: Boehmenan concentration-dependently suppressed proliferation and induced G1 phase arrest in A549 NSCLC cells, which were accompanied by reduction of migration, colony formation and increase of apoptosis in A549 cells. In addition, boehmenan treatment markedly modulated apoptosis-related protein (p53, p21, cleaved caspase 3, and cleaved PARP) and cyclin D1 expression and induced ΔΨm collapse in a concentration dependent manner. Furthermore, boehmenan concentration-dependently inhibited EGF-induced activation of EGFR and its downstream signaling molecules, including MEK, Akt, ERK1/2, and STAT3. CONCLUSION: Taken together, our results suggested that boehmenan-mediated anti-tumor property was mediated by modulation of mitochondria and EGFR signaling pathway in A549 NSCLC cells.