Hsps are up-regulated in melanoma tissue and correlate with patient clinical parameters

Heat shock proteins (hsps) have been studied in numerous cancer types, but a clear view of their clinical relevance in melanoma remains elusive. Therefore, the aim of this study was to investigate the expression of hsps in melanoma with respect to patient clinical parameters. Using Western immunoblotting, hsps 90, 70, 60, 40 and 32 were observed to be widely expressed in metastatic melanomas (n = 31), while immunofluorescence demonstrated that in the majority of samples these hsps, apart from hsp32, were increased in expression in melanoma cells compared with surrounding non-melanoma cells in situ (n = 8). Correlating hsp expression with patient clinical parameters indicated that greater hsp90 (P < 0.02) and hsp40 (P < 0.03) expression correlated with advanced stage (stage III Vs stage IV), while in the case of hsp40, this was additionally associated with reduced patient survival (P < 0.05). In contrast, higher hsp32 expression was associated with improved patient survival (P < 0.007). On the other hand, the expression of the other hsps did not correlate with any obtainable patient clinical parameters. This study provides further evidence for the importance of hsps in melanoma and for their use as therapeutic targets and biomarkers, but larger-scale follow-up studies are required to confirm these results.

Electronic supplementary material

The online version of this article (doi:10.1007/s12192-012-0363-1) contains supplementary material, which is available to authorized users.     

Changes in Ubiquitin Conjugates and Hsp72 Levels During Arm Regeneration in Echinoderms

All organisms show a common defensive mechanism that results in the expression of conserved heat shock proteins (Hsps). These proteins function in a wide range of stressful conditions. We have monitored their levels in species of regenerating echinoderms with different mechanisms of regeneration and from different geographical locations. The effect of an artificial higher temperature on expression of Hsps was also studied. Two stress proteins (Hsp72 and ubiquitin) that are important in processes such as development and protein degradation were investigated. Using Western blot analysis and immunocytochemistry, we found significant changes in the level (Hsp72) and pattern of conjugation (ubiquitin) that corresponded with the repair phase (early regenerative stages) and with the later growth and regeneration of new tissues. Animals from the intertidal environment showed a distinctly sustained expression pattern of Hsp72 compared with benthic animals which suggests a functionally adaptative and dynamic stress response program. Accepted March 1, 2000.     

The level of Hsp27 in lymphocytes is negatively associated with a higher risk of lung cancer

Heat shock proteins (Hsps) can protect cells, organs, and whole organisms against damage caused by abnormal environmental hazards. Some studies have reported that lymphocyte Hsps may serve as biomarkers for evaluating disease status and exposure to environmental stresses; however, few epidemiologic studies have examined the associations between lymphocyte Hsps levels and lung cancer risk. We examined lymphocyte levels of Hsp27 and Hsp70 in 263 lung cancer cases and age- and gender-matched cancer-free controls by flow cytometry. Multivariate logistic regression models were used to estimate the association between lymphocyte Hsps levels and lung cancer risk. Our results showed that Hsp27 levels were significantly lower in lung cancer cases than in controls (16.5 vs 17.8 mean fluorescence intensity, P < 0.001). This was not observed for Hsp70 levels. Further stratification analysis revealed that lymphocyte Hsp27 levels were negatively associated with lung cancer risk especially in males and heavy smokers. There was a statistical trend of low odd ratios (95% confidence intervals) and upper tertile levels of Hsp27 [1.000, 0.904 (0.566–1.444) and 0.382 (0.221–0.658, P _trend = 0.001) in males and 1.000, 0.9207 (0.465–1.822) and 0.419 (0.195–0.897, P _trend = 0.036) in heavy smokers] after adjustment for confounding factors. These results suggest that lower lymphocyte Hsp27 levels might be associated with an increased risk of lung cancer. Our findings need to be validated in a large prospective study. Feng Wang and Maohui Feng contributed equally to this work.     

Dynamic processes that reflect anti-apoptotic strategies set up by HspB1 (Hsp27)

Human HspB1 (also denoted Hsp27) is an oligomeric anti-apoptotic protein that has tumorigenic and metastatic roles. To approach the structural organizations of HspB1 that are active in response to apoptosis inducers acting through different pathways, we have analyzed the relative protective efficiency induced by this protein as well its localization, oligomerization and phosphorylation. HeLa cells, that constitutively express high levels of HspB1 were treated with either etoposide, Fas agonist antibody, staurosporine or cytochalasin D. Variability in HspB1 efficiency to interfere with the different apoptotic transduction pathways induced by these agents were detected. Moreover, inducer-specific dynamic changes in HspB1 localization, native size and phosphorylation were observed, that differed from those observed after heat shock. Etoposide and Fas treatments gradually shifted HspB1 towards large but differently phosphorylated oligomeric structures. In contrast, staurosporine and cytochalasin D induced the rapid but transient formation of small oligomers before large structures were formed. These events correlated with inducer-specific phosphorylations of HspB1. Of interest, the formation of small oligomers in response to staurosporine and cytochalasin D was time correlated with the rapid disruption of F-actin. The subsequent, or gradual in the case of etoposide and Fas, formation of large oligomeric structures was a later event concomitant with the early phase of caspase activation. These observations support the hypothesis that HspB1 has the ability, through specific changes in its structural organization, to adapt and interfere at several levels with challenges triggered by different signal transduction pathways upstream of the execution phase of apoptosis.     

Identification of Hsc70 as an influenza virus matrix protein (M1) binding factor involved in the virus life cycle

Influenza virus matrix protein 1 (M1) has been shown to play a crucial role in the virus replication, assembly and budding. We identified heat shock cognate protein 70 (Hsc70) as a M1 binding protein by immunoprecipitation and MALDI-TOF MS. The C terminal domain of M1 interacts with Hsc70. We found that Hsc70 does not correlate with the transport of M1 to the nucleus, however, it does inhibit the nuclear export of M1 and NP, thus resulting in the inhibition of viral production. This is the first demonstration that Hsc70 is directly associated with M1 and therefore is required for viral production.     

Transient expression and heat-stress-induced co-aggregation of endogenous and heterologous small heat-stress proteins in tobacco protoplasts

Heat-stress granules (HSG) are highly ordered, cytoplasmic chaperone complexes found in all heat-stressed plant cells. We have developed an experimental system involving expression of cytosolic class I and class II small heat-stress proteins (Hsps) of pea, Arabidopsis and tomato in tobacco protoplasts to study the structural prerequisites for the assembly of HSG or HSG-like complexes. Class I and class II small Hsps formed class-specific dodecamers of 210-280 kDa, which, upon heat stress, were incorporated into HSG complexes. Interestingly, class II dodecamers alone could form HSG-like complexes (auto-aggregation), whereas class I dodecamers could do so only in the presence of class II proteins (recruitment). By analysing C-terminal deletion forms of Hsp17 class II, we obtained evidence that the intact C-terminus is critical for the oligomerization state, for the heat-stress-induced auto-aggregation and for recruitment of class I proteins. The class-specific formation of dimers as a prerequisite for oligomerization was analysed by the yeast two-hybrid system. In the presence of the endogenous (tobacco) set of heat-stress-induced proteins, all heterologous class I and class II proteins were incorporated into HSG complexes, whose ultrastructure was different from that of complexes formed by class I and class II proteins alone. Although other, more distantly related, members of the Hsp20 family, i.e. the plastidic pea Hsp21, the Drosophila Hsp23 and the mouse Hsp25, were well expressed in tobacco protoplasts and formed homo-oligomers of 200-700 kDa, none of them could be recruited to HSG complexes.     

Microbial small heat shock proteins and their use in biotechnology

Small heat shock proteins (sHsps) exist in almost all organisms. Most organisms have more than one sHsp, but their number can be as high as 65, as found in the eukaryote, Vitis vinifera. The function of sHsps is well-known; they confer thermotolerance to cellular cultures and proteins in cellular extracts during prolonged incubations at elevated temperatures. This demonstrates the ability of sHsps to protect cellular proteins, and to maintain cellular viability under conditions of intensive stress, such as heat shock or chemical treatments. sHsps have several properties that distinguish them from heat shock proteins (Hsps): they function as ATP-independent chaperones, require the flexible assembly and reassembly of oligomeric complex structures for their activation, and exhibit a wide range of substrate-binding capacities. Recent studies indicate that sHsps have important biological functions in thermostability, disaggregation, and proteolysis inhibition. These functions can be harnessed for various applications, including nanobiotechnology, proteomics, bioproduction, and bioseparation. In this review, we discuss the properties and diversity of microbial sHsps, as well as their potential uses in the biotechnology industry.     

Hsp提高细菌的逆境生存能力和乙醇产量

目的：用热休克蛋白Hsp（HeatShockProteins）基因重组大肠杆菌,改善细胞生长状况、提高大肠杆菌的逆境耐受性和乙醇产量。方法：将来自Pyrococcus加诬凇的基因Hsp与Lac启动子串联,构建成由Lae启动子调控Hsp表达的操纵子,经该操纵子转化的大肠杆菌分别在高渗透压、酸性条件、高温和高糖的条件下发酵,利用气相色谱检测发酵液中的乙醇含量。结果：含有Hsp基因的工程菌与不含Hsp基因的对照菌相比,在0．4mol／LNaCl的高渗透压下乙醇产量提高1．5倍、在pH4．5的酸性条件下提高1．2倍、在高温高糖的条件下提高5．95倍。结论：热休克蛋白Hsp基因的表达可以提高大肠杆菌在逆境中的代谢能力。     

Differential regulation of anti-inflammatory proteins in human rheumatoid synoviocyte MH7A cell by celecoxib and ibuprofen

Non-steroidal anti-inflammatory drugs are known to be the most widely used drugs to exert their anti-inflammatory activities. It was examined protein expression profiles of human rheumatoid fibroblast-like synoviocyte MH7A cells treated with celecoxib, a selective cyclooxygenase-2 inhibitor, or ibuprofen, a non-selective cyclooxygenase inhibitor, using two-dimensional gel electrophoresis for comparison the mechanism of the drugs. Altered expression pattern in response to celecoxib is significantly different from that of ibuprofen treated cells. When MH7A cells were treated with celecoxib, 28 proteins were affected at their expression levels. Among them, heat shock proteins (Hsp60 and 70), glucose regulated proteins (Hsp75 and 78) were observed to be up-regulated by 1 to 30 microM concentrations of celecoxib but those proteins were not affected in ibuprofen treated cells. On the other hand, the expression of 19 proteins was changed by ibuprofen and the expression of apolipoprotein E, RNA binding motif 4, CTP-phosphocholine cytidylyltransferase, and phospholipase A2 inhibitory protein was only altered by ibuprofen. The expressions of 15 proteins were affected by both celecoxib and ibuprofen. Our results showed that celecoxib and ibuprofen, though they are known to act as cyclooxygenase inhibitors, could exert a different mode of acting mechanisms in anti-inflammatory processes. The chemical proteomic approach will be useful for figuring out the mode of actions of drugs.     

Field studies on the relation between the accumulation of heavy metals and metabolic and HSR in the bearded horse mussel Modiolus barbatus

The present study aims to examine whether the seasonal changes in the levels of heavy metals Cd and Pb in the gills of sublittoral mussel Modiolus barbatus from populations distributed in Thermaikos Gulf are correlated to seasonal molecular (Heat Shock Response) and metabolic stress responses of this species. Our results indicate a season effect in the accumulation of heavy metals in the gills of bivalves in the area of Thermaikos Gulf, possibly implicating biological (reproductive cycle), natural (rivers' flow) and anthropogenic factors. Among the members of heat shock proteins (Hsps) examined, inducible Hsp70 seemed to play a major cytoprotective role against toxicity of metals. However, bivalves' tolerance against heavy metals may decrease during warming, arising further questions for their survival in context of global warming.