Anticancer effects of NSC-631570 (Ukrain) in head and neck cancer cells: In vitro analysis of growth, invasion, angiogenesis and gene expression

NSC-631570 (Ukrain) is an aqueous extract of Chelidonium majus, a herbaceous perennial plant, one of two species in the genus Chelidonium, which has been demonstrated to selectively kill tumor cells without affecting non-malignant cells. In the present study, the components of NSC-631570 were examined by combined liquid chromatography/mass spectroscopy (LC-MS) and the effects of NSC-631570 on HNSCC cell lines, as well as primary cells, were analyzed with respect to growth, apoptosis, invasion, angiogenesis and gene expression. LC-MS identified chelerythrine and allocryptopine as the major alkaloids of the extract. Moreover, NSC-631570 suppressed the growth of all tested HNSCC cell lines, including a paclitaxel-resistant and P-glycoprotein (MDR1)-overexpressing cell line. Mucosal keratinocytes were also affected by the extract, while fibroblasts proved to be much more resistant. In contrast to allocryptopine, chelerythrine had toxic effects on HNSCC cell lines at low doses. NSC-631570 significantly induced apoptosis in the FaDu and HLaC78 cell lines. As analyzed by a spheroid-based invasion assay, cell migration was significantly suppressed by NSC-631570 in FaDu cells on gelatine, fibronectin, collagen, laminin and Matrigel((R)). Migration of the highly invasive cell line HLaC78 was also inhibited, albeit to a lesser extent (not significant on laminin). Microarray analysis revealed the downregulation of genes encoding key regulators, including EGFR, AKT2, JAK1, STAT3 and ss -catenin (CTNNB1), all of which are involved in cell proliferation, migration, angiogenesis, apoptosis as well as the radiation- and chemo-resistance of HNSCC. The strongest upregulation occurred for cytochrome P450 1A1 (CYP1A1) and 1B1 (CYP1B1), involved in the metabolism of xenobiotics. Upregulation of CYP1A1 was at least partially caused by chelerythrine and allocryptopine, as shown by RT-qPCR in two HNSCC cell lines. In addition, NSC-631570 showed a high anti-angiogenic action on the tube formation ability of human umbilical vein endothelial cells (HUVECs). In conclusion, this study highlights NSC-631570 as a promising therapeutic approach for HNSCC.