Casticin Induces DNA Damage and Affects DNA Repair Associated Protein Expression in Human Lung Cancer A549 Cells

Abstract

Casticin was obtained from natural plants, and it has been shown to exert biological functions; however, no report concerns the induction of DNA damage and repair in human lung cancer cells. The objective of this study was to investigate the effects and molecular mechanism of casticin on DNA damage and repair in human lung cancer A549 cells. Cell viability was determined by flow cytometric assay. The DNA damage was evaluated by 4’,6-diamidino-2-phenylindole (DAPI) staining and electrophoresis which included comet assay and DNA gel electrophoresis. The protein levels associated with DNA damage and repair were analyzed by western blotting. The expression and translocation of p-H2A.X were observed by confocal laser microscopy. Casticin reduced total viable cell number and induced DNA condensation, fragmentation, and damage in A549 cells. Furthermore, casticin increased p-ATM at 6 h and increased p-ATR and BRCA1 at 6–24 h treatment but decreased p-ATM at 24–48 h, as well as decreased p-ATR and BRCA1 at 48 h. Furthermore, casticin decreased p-p53 at 6–24 h but increased at 48 h. Casticin increased p-H2A.X and MDC1 at 6–48 h treatment. In addition, casticin increased PARP (cleavage) at 6, 24, and 48 h treatment, DNA-PKcs and MGMT at 48 h in A549 cells. Casticin induced the expressions and nuclear translocation of p-H2AX in A549 cells by confocal laser microscopy. Casticin reduced cell number through DNA damage and condensation in human lung cancer A549 cells.

Casticin protected against neuronal injury and inhibited the TLR4/NF‐κB pathway after middle cerebral artery occlusion in rats

“…Casticin is a flavonoid extracted from Rhizoma butensis , which has various biological effects such as anti‐tumor, anti‐inflammatory, and improvement of airway responses in asthma 12‐14 . Besides, it has remarkable effects on nuclear factor, erythroid 2‐like 2 (Nrf2), kelch‐like ECH‐associated protein 1 (Keap1), NF‐κB, and other targets of oxidative stress and inflammation 15 .…”

Isochorismatase domain-containing protein 1 (ISOC1) participates in DNA damage repair and inflammation-related pathways to promote lung cancer development

“…Co-IP and MS assays revealed that ISOC1 could interact with the DNA damage repair pathway, and further investigation confirmed that overexpression of ISOC1 led to increased DNA damage sites. Dysregulation in the DNA damage repair pathway induces the accumulation of genetic alteration and facilitates carcinogenesis in lung cancer (22). RNA sequencing results showed that the main downstream signaling pathway mediated by ISOC1 was inflammationrelated pathways, including IL-17 signaling pathway, TNF signaling pathway, cytokine-cytokine receptor interaction, NF-kappa B signaling pathway, chemokine signaling pathway, and others.…”

Tetrandrine Enhances H2O2-Induced Apoptotic Cell Death Through Caspase-dependent Pathway in Human Keratinocytes

“…HaCaT cells (3×10 6 cells/dish) were cultured onto 10-cm dishes overnight and treated with DMSO, 500 μM H 2 O 2 or pre-treated with 20 μM tetrandrine for 1 h and then treated with 500 μM H 2 O 2 for 12 h. At the end of incubation, cells were collected, total proteins were extracted, and their protein concentration was quantified by Bio-Rad protein assay kit (Hercules, CA, USA) (40)(41)(42). A defined amount of sample (30 μg) from each treatment was separated by 10% (w/v) sodium dodecyl sulfate polyacrylamide gel electrophoresis and then transferred onto polyvinylidene fluoride membranes (Millipore, Belford, MA, USA).…”