The Antitumoral/Antimetastatic Action of the Flavonoid Brachydin A in Metastatic Prostate Tumor Spheroids In Vitro Is Mediated by (Parthanatos) PARP-Related Cell Death
Diego Luís Ribeiro, Katiuska Tuttis, Larissa Cristina Bastos de Oliveira, Juliana Mara Serpeloni, Izabela Natália Faria Gomes, André van Helvoort Lengert, Claúdia Quintino da Rocha, Rui Manuel Reis, Ilce Mara de Syllos Cólus, Lusânia Maria Greggi Antunes
Abstract
, displays a remarkable antitumoral effect against in vitro mPCa cells cultured as bidimensional (2D) monolayers. Considering that three-dimensional (3D) cell cultures provide a more accurate response to chemotherapeutic agents, this study investigated the antiproliferative/antimetastatic effects of BrA and the molecular mechanisms underlying its action in mPCa spheroids (DU145) in vitro. BrA at 60-100 μM was cytotoxic, altered spheroid morphology/volume, and suppressed cell migration and tumor invasiveness. High-content analysis revealed that BrA (60-100 µM) reduced mitochondrial membrane potential and increased apoptosis and necrosis markers, indicating that it triggered cell death mechanisms. Molecular analysis showed that (i) 24-h treatment with BrA (80-100 µM) increased the protein levels of DNA disruption markers (cleaved-PARP and p-γ-H2AX) as well as decreased the protein levels of anti/pro-apoptotic (BCL-2, BAD, and RIP3K) and cell survival markers (p-AKT1 and p-44/42 MAPK); (ii) 72-h treatment with BrA increased the protein levels of effector caspases (CASP3, CASP7, and CASP8) and inflammation markers (NF-kB and TNF-α). Altogether, our results suggest that PARP-mediated cell death (parthanatos) is a potential mechanism of action. In conclusion, BrA confirms its potential as a candidate drug for preclinical studies against mPCa.