Correlative evaluation of anticancer effects of a modified methioninase MGL-KPV using 2D and 3D cell models, human cancer xenografts in zebrafish embryos and Balb/c nude mice

Purpose The emergence of new models of tumor growth requires a comparison of the results of the evaluation of the anticancer effect of single drug candidate for the selection of a relevant model. Methods We assessed the anticancer activity of the modified enzyme MGL-KPV using four models: 2D cultures, 3D spheroids, zebrafish embryo xenografts, and Balb/c nude mice. Cytotoxicity was tested in cancer cell lines and fibroblasts; efficacy was evaluated in zebrafish and mice. The effect of MGL does not require direct contact with cancer cells, making it unique drug candidate for in vitro and in vivo comparison. Results MGL-KPV showed selective cytotoxicity with IC 50 values of 0.23–2.21 U/mL (2D) and 1.43–4.82 U/mL (3D), sparing fibroblasts. HCT-116 and Panc-1 were most sensitive. In zebrafish xenografts, tumor size reduced by 70% (HCT-116) and 43% (Panc-1); in mice — by 45% and 34%, respectively. Conclusions MGL-KPV demonstrated significant anticancer activity across all models. These results support step-by-step non-clinical proof-of-concept studies approach for amino-acid cleaving enzymes with anticancer properties.