## Abstract The role of c‐Jun NH~2~‐terminal kinase (JNK) signaling cascade in the stress‐inducible phosphorylation of heat shock factor 1 (HSF1) was investigated using known agonists and antagonists of JNK. We showed that treatment of HeLa cells with MG132, a proteasome inhibitor and known JNK act
Dynamic regulation and involvement of the heat shock transcriptional response in arsenic carcinogenesis
✍ Scribed by Sara Khalil; Jason Luciano; Wenjun Chen; Alice Y.-C. Liu
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 416 KB
- Volume
- 207
- Category
- Article
- ISSN
- 0021-9541
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The objective of this study is to better define induction of the heat shock response by arsenite, and to evaluation if induction of heat shock proteins (HSPs) contributes to the carcinogenic activity of arsenite. We show here that arsenite is a ubiquitous inducer of the heat shock response in mammalian cells: that it activated heat shock transcription factor 1 (HSF1) DNA‐binding activity, enhanced hsp 70 promoter, and induced hsp70mRNA and synthesis of HSP chaperones. Using a high throughput hsp70 promoter‐luciferase reporter assay, we observed a hormetic dose response where low concentrations of arsenite stimulated and high concentrations inhibited. Further, the response was time‐dependent such that with longer times of incubation, the dose response shifted to the left. The effect of arsenite in inducing the hsp 70‐luciferase reporter absolutely required a functional HSF1 as it was not observed in HSF1 minus cells but re‐instated by expression of HSF1. Consistent with the suggestion that arsenic targets vicinal cysteine‐SH, we showed that dithiothreitol blocked the effect of arsenite. Assays of cell viability and caspase showed that arsenite caused a dose‐dependent increase in cell death by activation of caspase 3/7 and pre‐induction of HSPs blunted these effects. Using anchorage independent cell growth as a late stage tumor promotion assay, we showed that low concentrations of arsenite had a growth promoting effect, which was enhanced by moderate heat shock. Our study provides evidence that induction of the heat shock response is a sensitive biomarker of arsenic exposure and that induction of HSPs likely contributes to the tumor promotion effect of arsenic. J. Cell. Physiol. 207: 562–569, 2006. © 2006 Wiley‐Liss, Inc.
📜 SIMILAR VOLUMES
The influence of cell hydration and taurine on the heat shock response was studied in primary rat hepatocytes. Heat-induced accumulation of inducible heat shock protein 70 (HSP70) mRNA and protein was increased under hypoosmotic conditions. In contrast, hyper-osmotic exposure blocked the HSP70 respo
Interferon (IFN) is not able to induce heat-shock protein (HSP) synthesis. However IFN pretreatment of mouse L cells has been shown to enhance the decrease of overall protein synthesis which follows a heat shock, and to stimulate the accumulation of HSPs. We show here that the synthesis of a protein
## BACKGROUND. The clinical value of heat-induced coagulation of prostatic tissue is evaluated as a minimally invasive treatment for patients with benign prostatic hyperplasia (BPH) and, more recently, localized prostate cancer (PC). To obtain a more detailed insight on the effect of heat on prost
## Abstract Human brahma‐related gene 1(__Brg1__) is a subunit of the switching/sucrose non‐fermenting (SWI/SNF) chromatin‐remodeling complex and regulates transcription during cell growth and differentiation and has been found to be mutated in many types of human cancers. Mammalian heat shock fact
## Abstract | I. | Introduction | 245 | | II. | Global Regulatory Networks | 245 | | III. | Heat‐Shock Response | 247 | | | A. Control Elements in Gram‐Positive Bacteria | 247 | | | 1. Sigma B‐Controlled Genes | 247 | | | 2. HrcA‐CIRCE Controlled Genes | 249 | | | 3. Genes Controlle