Effect of chelidonine on growth, invasion, angiogenesis and gene expression in head and neck cancer cell lines

The greater celandine 'Chelidonium majus' and its main alkaloid chelidonine have previously been shown to exert high cytotoxicity against cancer cells. Furthermore, chelidonine is proposed to possess pro-apoptotic and anti-metastatic properties. Within the present study, the effects chelidonine on several HNSCC cell lines, as well as primary cells, were analyzed with respect to growth, migration, angiogenesis and apoptosis. Chelidonine suppressed the growth of all tested HNSCC cell lines, including a paclitaxel-resistant and P-glycoprotein (MDR1) overexpressing cell line, but not in a clear dose-dependent manner. Mucosal keratinocytes were also strongly affected by chelidonine, while fibroblasts proved to be much more resistant. Chelidonine failed to trigger apoptosis at physiological concentrations in HNSCC cell lines. Based on a spheroid invasion model chelidonine suppressed invasion of FaDu cells effectively on gelatin, fibronectin, collagen I, laminin and Matrigel (R). However, invasion inhibition of the more aggressively invading cell line HLaC78 largely failed. Using the tube formation assay, chelidonine effectively inhibited angiogenesis. Expression analysis revealed an upregulation of the xenobiotic metabolism genes CYP1A1 and MDR1 by chelidonine. In summary, chelidonine appeared to exert only minor impact on head and neck cancer cells. Chelidonine did not produce clear dose-dependent and cell-type specific cytotoxicity nor did it trigger apoptosis strongly.