b.End5

Six Drugs Presented no Toxicity to BMECs and did not Increase BCCs Viability

BCBM is a severe condition with limited therapeutic options, highlighting the need for preventive strategies. Here, Godinho-Pereira et al. used BCCs (4T1) and BBB endothelial cells (b.End5) to identify drugs toxic to 4T1 cells but safe for b.End5 cells.

To ensure the safety of drugs targeting the blood-brain barrier (BBB) for brain microvascular endothelium, an initial viability assay using the MTT test was performed on b.End5 cells to determine safe concentrations for 15 drugs (Fig. 1). The results showed that Mol3, Mol5, DH, and DM exhibited toxic effects at all tested concentrations. Mol1 and BKM120 were toxic at 1 µM, while most drugs showed toxicity at concentrations ≥10 µM (Mol2, Mol4, CI-1033, KW-2478, MB, and MH). FTY720 was toxic only at 100 µM. Mol6 and FTY720-P showed no toxicity at any tested concentration and even increased cell viability at low concentrations (0.001, 0.01, and 0.1 µM). Based on these findings, Mol2, Mol4, Mol6, KW-2478, BKM120, FTY720, FTY720-P, MB, and MH were selected for further screening with 4T1 cells to ensure they did not promote an increase in tumor cell viability (Fig. 2). These drugs were tested at 0.1 and 1 µM, except for BKM120, which was tested at 0.01 and 0.1 µM. The results indicated that Mol2 and Mol4 increased tumor cell viability, with FTY720 only increasing BCCs viability at the lowest concentration. Mol6, BKM120, FTY720-P, MB, and MH had no effect, while KW-2478 decreased viability at 0.1 µM.