Scutebarbatine A induces ROS-mediated DNA damage and apoptosis in breast cancer cells by modulating MAPK and EGFR/Akt signaling pathway.

Abstract

Scutebarbatine A (SBT-A), a diterpenoid alkaloid, has exerted cytotoxicity on hepatocellular carcinoma cells in our previous works. Here, the antitumor activity of SBT-A in breast cancer cells and the underlying mechanism were explored. The anti-proliferative effect of SBT-A was measured by trypan blue staining, 5-ethynyl-2'-deoxyuridine (EdU) incorporation and colony formation assay. DNA double-strand breaks (DSBs) were evaluated by observing the nuclear focus formation of γ-H2AX. Cell cycle distribution was assessed by flow cytometry. Apoptosis was determined by a TUNEL assay. Intracellular reactive oxygen species (ROS) generation and superoxide production were measured with 2', 7'-dichlorofluorescein diacetate (DCFH-DA) and dihydroethidium (DHE) staining, respectively. The results indicated that SBT-A showed a dose-dependent cytotoxic effect against breast cancer cells while revealing less toxicity toward MCF-10A breast epithelial cells. Moreover, SBT-A remarkably induced DNA damage, cell cycle arrest and apoptosis in both MDA-MB-231 and MCF-7 cells. SBT-A treatment increased the levels of ROS and cytosolic superoxide production. Pretreatment with N-acetyl cysteine (NAC), a ROS scavenger, was sufficient to block viability reduction, DNA damage, apoptosis and endoplasmic reticulum (ER) stress caused by SBT-A. By exposure to SBT-A, the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38MAPK) was upregulated, while the phosphorylation of extracellular signal-regulated kinase (ERK) was downregulated. In addition, SBT-A inhibited the EGFR signaling pathway by decreasing EGFR expression and phosphorylation of Akt and p70S6K. As mentioned above, SBT-A has a potent inhibitory effect on breast cancer cells through induction of DNA damage, apoptosis and ER stress via ROS generation and modulation of MAPK and EGFR/Akt signaling pathway.

• Authors: Xiao-Shan Hao, Pan-Pan Feng, Yun-Yun Zhang, Feng-Ze Wang, Gui-Ling Wang, Hong-Rong Fei
• Journal: Chemico-biological interactions (Chem Biol Interact) Vol. 378 Pg. 110487 (Jun 01 2023) ISSN: 1872-7786 [Electronic] Ireland
• PMID: 37072049 (Publication Type: Journal Article)
• Copyright: Copyright © 2023 Elsevier B.V. All rights reserved.

Chemical References

• Reactive Oxygen Species
• Proto-Oncogene Proteins c-akt
• Superoxides
• scutebarbatine A
• Antineoplastic Agents
• p38 Mitogen-Activated Protein Kinases
• ErbB Receptors
• EGFR protein, human

Topics

• Humans
• Female
• Reactive Oxygen Species (metabolism)
• Proto-Oncogene Proteins c-akt (metabolism)
• Superoxides
• Breast Neoplasms (drug therapy)
• Signal Transduction
• Antineoplastic Agents (pharmacology)
• p38 Mitogen-Activated Protein Kinases (metabolism)
• Apoptosis
• DNA Damage
• ErbB Receptors (metabolism)
• MAP Kinase Signaling System
• Cell Line, Tumor