Kigelia africana inhibits proliferation and induces cell death in stage 4 Neuroblastoma cell lines

Neuroblastoma (NB) is one of the most common solid pediatric tumors and especially high-risk NBs still account for about 12-15% of cancer related deaths in children. Kigelia africana (KA) is a plant used in traditional African medicine which has already shown its anti-cancer potential in several in vitro and in vivo studies. The aim of this study is to evaluate the effect of KA fruit extract on stage 4 high-risk NB cells. Therefore, NB cell lines with and without MYCN amplification and non-neoplastic cells were treated with KA fruit extract at different concentrations. The effect of KA on cell viability and apoptosis rate were assessed by bioluminescence-/fluorescence-based assays. Several proteins involved in survival, tumor growth, inflammation and metastasis were detected via western blot and immunofluorescence. Secreted cytokines were detected via ELISA. Phytochemical composition of the extract was analyzed by liquid chromatography with tandem mass spectrometry (LC/MS/MS). Our group demonstrates a dose- and time-dependent selective cytotoxic effect of KA fruit extract on NB, especially in MYCN non-amplified tumor cells, by inhibiting cell proliferation and inducing cell death. Western blot and immunofluorescence results demonstrate a regulation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), disialoganglioside GD2 and epidermal growth factor receptor (EGFR) in KA-treated tumor cells. Our results evidence striking anti-cancer properties of KA fruit and pave the way for further surveys on the therapeutic properties and mechanisms of action in NB.