Dehydrodieugenol isolated from Ocotea cymbarum induces cell death in human breast cancer cell lines by dysregulation of intracellular copper concentration

Author(s)

Gomes, Kaio S. ; Coelho, Julia A. ; Gomes, Rafael N. ; Bosquetti, Lucas M. ; Lange, Camila N. ; Batista, Bruno L. ; Cerchiaro, Giselle ; Lago, Joao Henrique G.

• Document type: Journal article
• Source: Chemico-Biological Interactions; v. 396, p. 6-pg., 2024-05-08.

Abstract

In this work, two neolignans - dehydrodieugenol (1) and dehydrodieugenol B (2) - were isolated from leaves of Ocotea cymbarum (H. B. K.) Ness. (Lauraceae). When tested against two human breast cancer cell lines (MCF7 and MDA-MB-231), compound 1 was inactive (IC50 > 500 mu M) whereas compound 2 displayed IC50 values of 169 and 174 mu M, respectively. To evaluate, for the first time in the literature, the synergic cytotoxic effects of compounds 1 and 2 with ion Cu2+, both cell lines were incubated with equimolar solutions of these neolignans and Cu (ClO4)(2)& sdot;6H(2)O. Obtained results revealed no differences in cytotoxicity upon the co-administration of compound 2 and Cu-2+. However, the combination of compound 1 and Cu2+ increases the cytotoxicity against MCF7 and MDA-MB-231 cells, with IC 50 values of 165 and 204 mu M, respectively. The activity of compound 1 and Cu2+ in MCF7 spheroids regarding the causes/effects considering the tumoral microenvironment were accessed using fluorescence staining and imaging by fluorescence microscopy. This analysis enabled the observation of a higher red filter fluorescence intensity in the quiescence zone and the necrotic core, indicating a greater presence of dead cells, suggesting that the combination permeates the spheroid. Finally, using ICP-MS analysis, the intracellular copper disbalance caused by mixing compound 1 and Cu2+ was determined quantitatively. The findings showcased a 50-fold surge in the concentration of Cu2+ compared with untreated cells (p > 0.0001) - 18.7 ng of Cu2+/mg of proteins and 0.37 ng of Cu2+/mg of protein, respectively. Conversely, the concentration of Cu2+ in cells treated with compound 1 was similar to values of the negative control group (0.29 ng of Cu2+/mg of protein). This alteration allowed us to infer that compound 1 combined with Cu2+ induces cell death through copper homeostasis dysregulation. (AU)

• FAPESP's process: 23/12447-1 - Searching for specialized metabolites from Brazilian floristic biodiversity as drug candidates for neglected tropical diseases
• Grantee: João Henrique Ghilardi Lago
• Support Opportunities: BIOTA-FAPESP Program - Regular Research Grants