psoralidin and Breast-Neoplasms

Psoralidin (PSO), a natural phenolic coumarin, was reported to have anti-cancer activities. PSO induced reactive oxygen species (ROS) generation in cancer cells. The role of ROS in its anti-cancer effect remains unclear.. This study was designed to investigate the potential roles of ROS in PSO-induced anti-cancer effect in MCF-7 breast cancer cells.. Effect of PSO on cancer cell proliferation was determined by MTT assay. Comet assay was used to determine DNA damage. Protein expression was detected by Western blotting. Autophagic vacuoles were detected by monodansylcadaverine (MDC) staining. ROS generation was measured by fluorescent probe. NOX4 localization was determined by immunofluorescence staining.. PSO treatment caused proliferation inhibition in time- and dose- dependent manners, which was partially reversed by N-acetyl cysteine (NAC) and diphenyleneiodonium (DPI). PSO induced DNA damage and increased protein expression of γ-H2AX, phosphorylation of ATM, ATR, Chk1, and Chk2. PSO induced autophagy as evidenced by the accumulation of autophagic vacuoles and alterations of autophagic protein expression. PSO-induced cell death was enhanced by autophagy inhibitor chloroquine (CQ). Furthermore, PSO treatment induced ROS formation, which was reversed by NAC or DPI pretreatment. The expression of NOX4 was significantly enhanced by PSO. Both NAC and DPI could reverse PSO-induced DNA damage and autophagic responses. In addition, silencing NOX4 by siRNA inhibited PSO-induced ROS generation, DNA damage, and autophagy.. Taken together, these results showed that PSO induced DNA damage and protective autophagy mediated by ROS generation in a NOX4-dependent manner in MCF-7 cells.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Autophagy; Benzofurans; Breast Neoplasms; Cadaverine; Cell Proliferation; Coumarins; DNA Damage; Dose-Response Relationship, Drug; Female; Fluorescent Dyes; Gene Silencing; Humans; MCF-7 Cells; NADPH Oxidase 4; NADPH Oxidases; Reactive Nitrogen Species; RNA, Small Interfering

Breast cancer stem cells (BCSCs) are characterized by high aldehyde dehydrogenase (ALDH) enzyme activity and are refractory to current treatment modalities, show a higher risk for metastasis, and influence the epithelial to mesenchymal transition (EMT), leading to a shorter time to recurrence and death. In this study, we focused on examination of the mechanism of action of a small herbal molecule, psoralidin (Pso) that has been shown to effectively suppress the growth of BSCSs and breast cancer cells (BCCs), in breast cancer (BC) models.. ALDH(-) and ALDH(+) BCCs were isolated from MDA-MB-231 cells, and the anticancer effects of Pso were measured using cell viability, apoptosis, colony formation, invasion, migration, mammosphere formation, immunofluorescence, and western blot analysis.. Psoralidin significantly downregulated NOTCH1 signaling, and this downregulation resulted in growth inhibition and induction of apoptosis in both ALDH(-) and ALDH(+) cells. Molecularly, Pso inhibited NOTCH1 signaling, which facilitated inhibition of EMT markers (β-catenin and vimentin) and upregulated E-cadherin expression, resulting in reduced migration and invasion of both ALDH(-) and ALDH(+) cells.. Together, our results suggest that inhibition of NOTCH1 by Pso resulted in growth arrest and inhibition of EMT in BCSCs and BCCs. Psoralidin appears to be a novel agent that targets both BCSCs and BCCs.

Topics: Antineoplastic Agents, Phytogenic; Benzofurans; Breast Neoplasms; Cell Movement; Cell Proliferation; Coumarins; Drug Resistance, Neoplasm; Female; Gene Silencing; Humans; Neoplasm Invasiveness; Neoplastic Stem Cells; Receptor, Notch1; Signal Transduction; Tumor Cells, Cultured