Photodynamic therapy (PDT) is an experimental cancer therapy inducing tumor tissue damage via photosensitizer-mediated oxidative cytotoxicity. A previous report indicates that oxidative stress induced by hydrogen peroxide or menadione activates the heat shock transcription factor in mouse cells but does not result in either increased transcription or translation of heat shock proteins (HSPs). O...

Heat-induced accumulation of hsp 30 mRNA (1.1 kb) during early development of Xenopus laevis was first detectable at the tailbud stage (stage 30-34). This contrasts with heat-induced accumulation of hsp 70 mRNA (2.7 kb) and ubiquitin mRNA (size range = 1.7-3.1 kb), which was first detectable at the mid- to late-blastula stage. Continuous exposure of tadpoles to a 33 degrees C heat shock resulte...

The heat shock response is a highly conserved "stress response" mechanism used by cells to protect themselves from potentially damaging insults. It often involves the upregulated expression of chaperone and heat shock proteins (HSPs) to prevent damage and aggregation at the proteome level. Like most cancers, brain tumor cells often overexpress chaperones/HSPs, probably because of the stressful ...

Replication-competent viruses are currently being evaluated for their cancer cell-killing properties. These vectors are designed to induce tumor regression after selective viral propagation within the tumor. However, replication-competent viruses have not resulted heretofore in complete tumor eradication in the clinical setting. Recently, heat shock has been reported to partially alleviate repl...

A series of heat-resistant mutants selected from a murine tumor cell line, RIF-1, display a markedly increased and stable resistance to heat shock. The mutant cell lines were analyzed for differences that may explain their increased resistance. Membrane lipid analysis showed no change in cholesterol content but an increase in the proportion of saturated fatty acids in the phospholipid fraction....

PURPOSE The aim of this study was to define the immunoreactive specificity of Porphyromonas gingivalis (P. gingivalis) heat shock protein (HSP) 60 in periodontitis and atherosclerosis. METHODS In an attempt to define the cross-reactive bacterial heat-shock protein with human self-antigen at molecular level, we have introduced a novel strategy for cloning hybridoma producing anti-P. gingivalis...

Human heat shock protein (hsp) 70 and bacterial protein groEL promote leakage of calcein from liposomes induced by human serum albumin signal peptide, by S. aureus alpha toxin or by diphtheria toxin. Hsp 70 and groEL, as well as two mycobacterial homologues hsp 71 and hsp 65, induce ion conducting pores across planar lipid bilayers at low or neutral pH. It is concluded that hsp induce pores in ...

We determined the expression of the constitutive (hsc 70) and inducible (hsp 70) forms of heat shock protein 70 mRNA and protein in human proximal tubule (HPT) cells exposed to lethal and sublethal concentrations of Cd(+2) under both acute and extended conditions of exposure. The HPT cells exhibited the classic heat shock response when subjected to a physical (heat) or chemical stress (sodium a...

While studying the quantitative relationship between hyperthermiainduced heat shock proteins (HSPs) and thermotolerance (TT), we ob served that heat induced a family of HSPs, particularly an HSP 70 family, that might be involved in the development of TT. When cells were heated for 10 min at 4S.S°C, they became thermotolerant to a second heat exposure at 45.5°C,with a thermotolerance ratio of ...

Heat-Shock Factor 1 (HSF1), master regulator of the heat-shock response, facilitates malignant transformation, cancer cell survival, and proliferation in model systems. The common assumption is that these effects are mediated through regulation of heat-shock protein (HSP) expression. However, the transcriptional network that HSF1 coordinates directly in malignancy and its relationship to the he...