Imiquimod activates p53-dependent apoptosis in a human basal cell carcinoma cell line
| Autor: | Hsin Yi Jiang, Jeng-Jer Shieh, Szu Wei Mu, Yi Ju Chen, Shi Wei Huang, Chun Ying Wu, Sin Ting Wang, Shu Hao Chang, Jun Kai Kao, Jau Ling Huang |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Programmed cell death Skin Neoplasms Time Factors DNA repair Active Transport Cell Nucleus Antineoplastic Agents Apoptosis Ataxia Telangiectasia Mutated Proteins Dermatology Transfection Biochemistry 03 medical and health sciences Cell Line Tumor Autophagy Humans Medicine Phosphorylation Molecular Biology Imiquimod Dose-Response Relationship Drug business.industry Cell cycle Cell biology Gene Expression Regulation Neoplastic 030104 developmental biology Carcinoma Basal Cell Cell culture Mutation Cancer cell Immunology Aminoquinolines RNA Interference Tumor Suppressor Protein p53 Signal transduction Reactive Oxygen Species business Signal Transduction |
| Zdroj: | Journal of Dermatological Science. 81:182-191 |
| ISSN: | 0923-1811 |
| DOI: | 10.1016/j.jdermsci.2015.12.011 |
| Popis: | Background The tumor suppressor p53 controls DNA repair, cell cycle, apoptosis, autophagy and numerous other cellular processes. Imiquimod (IMQ), a synthetic toll-like receptor (TLR) 7 ligand for the treatment of superficial basal cell carcinoma (BCC), eliminates cancer cells by activating cell-mediated immunity and directly inducing apoptosis and autophagy in cancer cells. Objective To evaluate the role of p53 in IMQ-induced cell death in skin cancer cells. Methods The expression, phosphorylation and subcellular localization of p53 were detected by real-time PCR, luciferase reporter assay, cycloheximide chase analysis, immunoblotting and immunocytochemistry. Using BCC/KMC1 cell line as a model, the upstream signaling of p53 activation was dissected by over-expression of TLR7/8, the addition of ROS scavenger, ATM/ATR inhibitors and pan-caspase inhibitor. The role of p53 in IMQ-induced apoptosis and autophagy was assessed by genetically silencing p53 and evaluated by a DNA content assay, immunoblotting, LC3 puncta detection and acridine orange staining. Results IMQ induced p53 mRNA expression and protein accumulation, increased Ser15 phosphorylation, promoted nuclear translocation and up-regulated its target genes in skin cancer cells in a TLR7/8-independent manner. In BCC/KMC1 cells, the induction of p53 by IMQ was achieved through increased ROS production to stimulate the ATM/ATR-Chk1/Chk2 axis but was not mediated by inducing DNA damage. The pharmacological inhibition of ATM/ATR significantly suppressed IMQ-induced p53 activation and apoptosis. Silencing of p53 significantly decreased the IMQ-induced caspase cascade activation and apoptosis but enhanced autophagy. Mutant p53 skin cancer cell lines were more resistant to IMQ-induced apoptosis than wildtype p53 skin cancer cell lines. Conclusion IMQ induced ROS production to stimulate ATM/ATR pathways and contributed to p53-dependent apoptosis in a skin basal cell carcinoma cell line BCC/KMC1. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect