Dados do Resumo

Título

Bioactive profile of dipeptidyl nitrile derivatives for different lineages of liver cancer cells

Introdução

Pancreatic, liver, and breast cancers have a high mortality rate and occurrence of metastasis. Chemotherapeutic agents are usually applied in this case with limited efficacy. Therefore, novel therapeutic alternatives are needed, and cysteine protease inhibitors constitute an option as a standalone or combination therapy. Cathepsins B, L, and S are involved in neoplastic processes and are targets for reversible covalent inhibitors. Among different types of cathepsin inhibitors, dipeptidyl nitrile derivatives have been studied for cancer types.

Objetivo

Here, we aim to identify bioactive chemicals from a series of dipeptidyl nitrile derivatives based on a previous bioactive chemical (coded Neq0780) against liver (HepG2 and HUH-7) cancer cell lines in contrast to non-tumoral (Balb/3T3 clone A31) cells.

Métodos

The MTT assay assessed the viability/cytotoxicity of the compounds after 48 and 72 h incubation with 1.0x104 cells/well, while colony formation used 300 cells/well with the crystal violet with 10% ethanol. The 3D culture was performed using a cell density of 0.5.104 cells/mL seeded in 200 μL of medium per well in a 96-well plate with 1% agarose. After 5 days, the spheroids were treated with the compound of interest. The final analysis was performed after 72 hours using propidium iodide and rezazurin. Microscopy assays were performed using acridine orange and mitochondrial and lysosome markers to determine cellular stress. Then, the combined therapy test was also carried out to verify whether it has a synergistic effect when combined with a set of concentrations for the reference chemotherapy (doxorubicin). The cell death and cathepsin expression were analyzed using the Western blot method.

Resultados

One dipeptidyl nitrile derivative showed cytotoxicity against tumor cells alone or in combination therapies, triggering cell stress, apoptosis, and DNA damage that leads to cathepsin expression alterations and death. The colony formation was reduced after treatment. The 3D culture assay showed a decrease in the size and viability of the spheroids. The microscopy assay confirmed the endoplasmic reticulum stress by using a set of cell markers.

Conclusões

These results indicate a novel set of bioactive small molecules that can inhibit autophagy and tumor progression, with implications for drug discovery of a novel liver cancer therapeutic approach.

Financiador do resumo

FAPESP (23/16111-8, 20/16799-1), CNPq (312086/2023-7)

Palavras Chave

in vitro assay; antineoplastic activity; drug discovery