Arsenic induced apoptosis in malignant melanoma cells is enhanced by menadione through ROS generation, p38 signaling and p53 activation
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Title |
Arsenic induced apoptosis in malignant melanoma cells is enhanced by menadione through ROS generation, p38 signaling and p53 activation |
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Creator |
Chowdhury, Rajdeep
Chowdhury, Suchandra Roychoudhury, Paromita Mandal, Chitra Chaudhuri, Keya |
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Subject |
Infectious Diseases and Immunology
Molecular & Human Genetics |
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Description |
Introduction Resistance to apoptosis is a prominent feature of melanoma. Pharmacological concentration of arsenic in combination with a widely known oxidant, menadione was explored in this study to synergistically sensitize malignant melanoma cells to apoptosis. The molecular mechanism of apoptosis and the signalingpathways involved were thoroughly investigated. Materials methods and results Menadione synergized NaAsO2 to significantly increase ROS generation and facilitate the major apoptotic signaling events: alteration of mitochondrial membrane potential, cytochrome c release and anti-apoptotic protein Bcl-2 down-regulation and subsequent activation of caspase-9 and caspase-3 followed by poly-ADP-ribose polymerase-1 cleavage. Antioxidant N-acetyl-L-cysteine antagonized these events. Investigation of the signaling-pathway revealed significant suppression of AP-1 activity but not NF-jB upon NaAsO2 and menadione application. An increase in p38 phosphorylation and p53 protein expression did also dictate the apoptotic response. Suppression of p38 activation with SB203580 and inhibition of p53 expression by siRNA attenuated apoptosis. Transfection of p53, in p53 null HCT cells augmented the apoptotic events. Moreover, the treatment also led to tumor size reduction in BALB/c mice developed by intra-dermal B16 mouse melanoma cell injection;however, it had no detectable pro-proliferative or proapoptotic effect on non-tumor keratinocytes, normal fibroblasts or PBMC. Conclusion This study thus provides an insight into innovative mechanisms of melanoma sensitization, a proper cure against which is still elusive. Taken together, our data also provides the first evidence of arsenic activity accentuation by menadione through modulation of specific signaling-pathways. |
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Date |
2009
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Type |
Article
PeerReviewed |
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Format |
application/pdf
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Identifier |
http://www.eprints.iicb.res.in/131/1/APOPTOSIS%2C14(1)%2C108%2D123%2C2009[134].pdf
Chowdhury, Rajdeep and Chowdhury, Suchandra and Roychoudhury, Paromita and Mandal, Chitra and Chaudhuri, Keya (2009) Arsenic induced apoptosis in malignant melanoma cells is enhanced by menadione through ROS generation, p38 signaling and p53 activation. Apoptosis, 14. pp. 108-123. |
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Relation |
http://dx.doi.org/10.1007/s10495-008-0284-8
http://www.eprints.iicb.res.in/131/ |
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