Enzymatic Laccase Nanoreactors Induce Apoptosis in MOLT-4-ALL Cells and Activate Prodrugs in a Synergetic Effect

The search for novel cancer treatment strategies is of great interest. Recently, it has been reported that laccases from various sources exhibit anti-tumor effects. In addition, the use of nanometric platforms for delivering therapeutic agents at the cellular level is a promising approach for efficient cancer treatment. In this work, the cytotoxicity of Coriolopsis gallica laccase on human leukemia MOLT-4 cells was evaluated.

Laccase was nanoconfined in a virus-like nanoparticle (VLPs) of the brome mosaic virus (BMV), and both free and nanoconfined preparations were evaluated the activation of prodrugs. The cytotoxicity was evaluated by neutral red to obtain the dose-response curve. Afterward, the death cell and mechanisms were characterized using flow cytometry of combinations of laccase (free and VLPs) with prodrugs (Doxorubicin, Irinotecan, and Procarbazine).

Laccase alone showed an apoptotic effect at a concentration of 0.35 μM (IC₂₀), with a 49% of apoptotic cells at 24 hours. This effect was enhanced by the presence of doxorubicin (63.79%), irinotecan (43.44%), and procarbazine (53.27%) in the presence of both the free version (Lac) and the nano-encapsidated version (VLP-saLac). A similar effect was observed for the necroptosis population. Finally, the CI (Combination Index) was estimated by two different models, and the synergistic effect on cell death was confirmed.

The laccase pro-apoptotic effect in MOLT-4 cells has been demonstrated, increasing cytotoxicity by activating prodrugs in both free and nanoconfined forms.