Kalantuboside B induced apoptosis and cytoprotective autophagy in human melanoma A2058 cells: An in vitro and in vivo study
| Autor: | Xuan-Zao Chen, Kai-Yuan Lin, Hsin-Ling Yang, Hui-Chi Huang, Hsin-Ju Cho, You-Cheng Hseu, Yugandhar Vudhya Gowrisankar, Varadharajan Thiyagarajan |
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| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Programmed cell death Cyclin A Mice Nude Apoptosis In Vitro Techniques Biochemistry 03 medical and health sciences Mice 0302 clinical medicine Downregulation and upregulation Physiology (medical) Autophagy Tumor Cells Cultured Animals Humans Melanoma Cell Proliferation Cyclin-dependent kinase 1 Mice Inbred BALB C biology Chemistry Cell Cycle Cell cycle Antineoplastic Agents Phytogenic Xenograft Model Antitumor Assays Cell biology Cardenolides 030104 developmental biology Cytoprotection biology.protein Female Signal transduction 030217 neurology & neurosurgery |
| Zdroj: | Free radical biologymedicine. 143 |
| ISSN: | 1873-4596 |
| Popis: | Kalantuboside B (KB), a natural bufadienolide derivative extracted from the succulent plant Kalanchoe tubiflora, is well-known for its cardiotonic, immunomodulatory, and anti-inflammatory properties. In this study, we tested in vitro and in vivo anti-cancer efficacy with low concentrations of KB (5–30 ng/mL; 8.7–52.2 nM) on A2058 melanoma cells; and for the molecular mechanisms that underlie them. KB significantly inhibited the cell viability and colony formation via arresting the cell cycle at G2/M phase. There was an association with a decrease in Cyclin A/B1, Cdc25C, and Cdc2 expressions. Further, this treatment indicated the induction of apoptosis, DNA fragmentation, cytochrome c release, and caspase-3, -8, -9, and -12 activation, and PARP cleavage, which shows that mitochondrial, death-receptor, and ER-stress signaling pathways are involved. KB-induced autophagy was apparent from enhanced LC3-II accumulation, GFP-LC3 puncta, and AVO formation. Surprisingly, KB-mediated cell death was potentiated by 3-MA and CQ to suggest the role of autophagy as a cytoprotective mechanism. Moreover, KB-treated A2058 cells enhanced intracellular ROS generation and antioxidant NAC prevented apoptosis and reversed cytoprotective autophagy. Interestingly, KB-induced apoptosis (PARP cleavage) and cytoprotective autophagy (LC3-II accumulation) were mediated by the up-regulation of the ERK signaling pathway. It was also shown that KB promoted cytoprotective autophagy by a calcium dependent-p53 downregulation pathway. In vivo data showed that KB suppressed tumor growth significantly in A2058-xenografted nude mice. A Western blot indicated cell-cycle inhibition (cyclin A reduction), apoptosis induction (PARP cleavage and Bcl-2 inhibition), and cytoprotective autophagy (LC3-II upregulation and p53 downregulation) in KB-treated A2058-xenografted mice. Our findings suggested that KB-induced ROS pathway plays a role in mediating the apoptosis and cytoprotective autophagy in human melanoma cells. Thus, KB is considered to be a putative anti-tumor agent. |
| Databáze: | OpenAIRE |
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