Prognostic and immunological roles of heat shock protein A4 in lung adenocarcinoma

BACKGROUND Heat shock protein A4(HSPA4)belongs to molecular chaperone protein family which plays important roles within variable cellular activities,including cancer initiation and progression.However,the prognostic and immunological significance of HSPA4 in lung adenocarcinoma(LUAD)has not been revealed yet.AIM To explore the prognostic and immunological roles of HSPA4 to identify a novel prognostic biomarker and therapeutic target for LUAD.METHODS We assessed the prognostic and immunological significance of HSPA4 in LUAD using data from The Cancer Genome Atlas database.The association between HSPA4 expression and clinical-pathological features was assessed through Kruskal-Wallis and Wilcoxon signed-rank test.Univariate/multivariate Cox regression analyses and Kaplan-Meier curves were employed to evaluate prognostic factors,including HSPA4,in LUAD.Gene set enrichment analysis(GSEA)was conducted to identify the key signaling pathways associated with HSPA4.The correlation between HSPA4 expression and cancer immune infiltration was evaluated using single-sample gene set enrichment analysis(ssGSEA).RESULTS Overexpressing HSPA4 was significantly related to advanced pathologic TNM stage,advanced pathologic stage,progression disease status of primary therapy outcome and female subgroups with LUAD.In addition,increased HSPA4 expression was found to be related to worse disease-specific survival and overall survival.GSEA analysis indicated a significant correlation between HSPA4 and cell cycle regulation and immune response,particularly through diminishing the function of cytotoxicity cells and CD8 T cells.The ssGSEA algorithm showed a positive correlation between HSPA4 expression and infiltrating levels of Th2 cells,while a negative correlation was observed with cytotoxic cell infiltration levels.CONCLUSION Our findings indicate HSPA4 is related to prognosis and immune cell infiltrates and may act as a novel prognostic biomarker and therapeutic target for LUAD.

Expression of heat shock proteins (HSP27, HSP60, HSP70, HSP90, GRP78, GRP94) in hepatitis B virus-related hepatocellular carcinomas and dysplastic nodules

AIM: Expression of heat shock proteins (HSPs) is frequently up-regulated in hepatocellular carcinoma (HCC), which evolves from dysplastic nodule (DN) and early HCC to advanced HCC. However, little is known about the differential expression of HSPs in multistep hepatocarcinogenesis. It was the purpose of this study to monitor the expression of HSPs in multistep hepatocarcinogenesis and to evaluate their prognostic significance in hepatitis B virus (HBV)related HCC.METHODS: Thirty-eight HCC and 19 DN samples were obtained from 52 hepatitis B surface antigen-positive Korean patients. Immunohistochemical and dot immunoblot analyses of HSP27, HSP60, HSP70, HSP90, glucoseregulated protein (GRP)78, and GRP94 were performed and their expression at different stages of HCC development was statistically analyzed.RESULTS: Expression of HSP27, HSP70, HSP90, GRP78, and GRP94 increased along with the stepwise progression of hepatocarcinogenesis. Strong correlation was found only in GRP78 (Spearman's r= 0.802). There was a positive correlation between the expressions of GRP78, GRP94, HSP90, or HSP70 and prognostic factors of HCC. Specifically, the expression of GRP78, GRP94, or HSP90 was associated significantly with vascular invasion and intrahepatic metastasis.CONCLUSION: The expressions of HSPs are commonly up-regulated in HBV-related HCCs and GRP78 might play an important role in the stepwise progression of HBVrelated hepatocarcinogenesis. GRP78, GRP94, and HSP90 may be important prognostic markers of HBV-related HCC, strongly suggesting vascular invasion and intrahepatic metastasis.

Heat Shock Proteins Inducement in Wheat Seedling

High temperature is an important limiting factor to the improvement of wheat yield. When suffered hot stress,wheat will produce a series of heat shock proteins to adapt this adversity. In different upgrowth phases,or different heat-resistant crop varieties,the heat shock protein exist differences. Therefore,study on differences of heat shock protein has significant theoretical and practical meaning for researching heat resistance of wheat. By using SDS-PAGE method,the inducing conditions and manifestation of heat shock protein were studied,which provided theoretical basis for yield increasing of wheat.

Preparation and application of a novel monoclonal antibody specific for the heat shock protein 60 of Lawsonia intracellularis

Porcine proliferative enteropathy(PPE),an important infectious disease in pig production caused by an obligate intracellular bacterium Lawsonia intracellularis,is commonly associated with diarrhea and reduced weight gain in growing pigs widespread.An accurate method for detecting L.intracellularis is particularly important for preventing and controlling PPE.Heat shock protein 60(Hsp60)is an immunodominant bacterial antigen found in all eukaryotic and prokaryotic organisms.Thus,the purpose of the current investigation was to produce a novel L.intracellularis Hsp60 monoclonal antibody(mAb)useful for immunodiagnostics.Three hybridomas secreted anti-Hsp60 termed 3E5,4E2,and 9G6 were generated,and the titers of ascitic fluids of 3E5,4E2,9G6 were 1:1024000,1:2048000 and 1:2048000,respectively.The Western blotting analysis demonstrated that recombinant Hsp60(rHsp60)was recognized by mAbs 3E5,4E2 and 9G6.Subsequently,analyses of specificity showed all the mAbs were highly specific to L.intracellularis while could not significantly react with other enteric bacteria commonly found in the ileum of pigs,such as Escherichia coli,Salmonella Choleraesuis,Salmonella Typhimurium,and Brachyspira hyodysenteriae.Furthermore,the mAbs were useful for detecting L.intracellularis in the infected monolayer cells and histological sections of the ileum from PPE-affected pigs.Our research will provide a foundation for the development of immunological diagnostic tests.

Glutamine supplementation attenuates intestinal apoptosis by inducing heat shock protein 70 in heatstroke rats

BACKGROUND:Heatstroke is the most hazardous heat-related illness and has a high fatality rate.We investigated whether glutamine supplementation could have a protective effect on heatstroke rats.METHODS:Twenty-five 12-week-old male Wistar rats(weight 305±16 g)were randomly divided into a control group(n=5),heatstroke(HS)group(n=10),and heatstroke+glutamine(HSG)group(n=10).Seven days before heat exposure,glutamine(0.4 g/[kg·d])was administered to the rats in the HSG group by gavage every day.Three hours after heat exposure,serum samples were collected to detect white blood cells,coagulation indicators,blood biochemical indicators,and inflammatory cytokines in the rats.The small intestine tissue was stained to analyze pathological structural changes and apoptosis.Finally,immunohistochemistry and Western blotting were used to analyze the expression levels of heat shock protein 70(HSP70).Multiple comparisons were analyzed by using one-way analysis of variance,and the Bonferroni test was conducted for the post hoc comparisons.RESULTS:After heat exposure,the core temperature of the HS group(40.65±0.31°C)was higher than the criterion of heatstroke,whereas the core temperature of the HSG group(39.45±0.14°C)was lower than the criterion.Glutamine supplementation restored the increased white blood cells,coagulation indicators,blood biochemical indicators,and inflammatory cytokines that were induced by heatstroke to normal levels.The intestinal mucosa was injured,and the structure of tight junctions was damaged in the HS group;however,the structure of intestinal mucosal epithelial cells was stable in the HSG group.Glutamine supplementation alleviated intestinal apoptosis and up-regulated HSP70 expression.CONCLUSION:Glutamine supplementation may alleviate intestinal apoptosis by inducing the expression of HSP70 and have a protective effect on heatstroke rats.

Association between heat shock factor protein 4 methylation and colorectal cancer risk and potential molecular mechanisms:A bioinformatics study

BACKGROUND We previously demonstrated that heat shock factor protein 4(HSF4)facilitates colorectal cancer(CRC)progression.DNA methylation,a major modifier of gene expression and stability,is involved in CRC development and outcome.AIM To investigate the correlation between HSF4 methylation and CRC risk,and to uncover the underlying molecular mechanisms.METHODS Differences in β values of HSF4 methylation loci in multiple malignancies and their correlation with HSF4 mRNA expression were analyzed based on Shiny Methylation Analysis Resource Tool.HSF4 methylation-related genes were identified by LinkedOmics in CRC,and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed.Protein-protein interaction network of HSF4 methylation-related genes was constructed by String database and MCODE algorithm.RESULTS A total of 19 CpG methylation loci were identified in HSF4,and their β values were significantly increased in CRC tissues and exhibited a positive correlation with HSF4 mRNA expression.Unfortunately,the prognostic and diagnostic performance of these CpG loci in CRC patients was mediocre.In CRC,there were 1694 HSF4 methylation-related genes;1468 of which displayed positive and 226 negative associations,and they were involved in regulating phenotypes such as immune,inflammatory,and metabolic reprogramming.EGFR,RELA,STAT3,FCGR3A,POLR2K,and AXIN1 are hub genes among the HSF4 methylation-related genes.CONCLUSION HSF4 is highly methylated in CRC,but there is no significant correlation between it and the prognosis and diagnosis of CRC.HSF4 methylation may serve as one of the ways in which HSF4 mediates the CRC process.

Effectiveness of conjunctival bleb scarring by knockdown of heat shock protein 47 in rat model

AIM:To evaluate the effectiveness of knock-down of heat shock protein 47(HSP47)on conjunctival bleb scarring in a rat model and its possible mechanism.METHODS:Male Sprague–Dawley rats were used for glaucoma filtration surgery(GFS)and were treated with either phosphate buffered solution,shControl,mitomycin C,or sh-HSP47 using a microsyringe immediately after GFS.The morphology of filtering blebs was observed postoperatively.The levels of HSP47 were analyzed at 2,5,8,and 11d after GFS via real‑time quantitative polymerase chain reaction(PCR)and Western blot.The silencing effect of HSP47,the expression of collagen I and III,and the potential signaling pathways of HSP47 during scarification were explored 11d post GFS.The protein levels of transforming growth factor-β1(TGF-β1),phospho-Smad2(pSmad2),phospho-Smad3(p-Smad3),and phospho-p38(p-p38)were also analyzed using Western blot.RESULTS:Sh-HSP47 treatment significantly prolonged the functional filtration bleb retention.The levels of HSP47 were increased significantly at 5,8,and 11d postoperatively compared to the control group(P<0.05,P<0.01,and P<0.001).The levels of HSP47 protein at day 11 postoperatively were significantly down-regulated after HSP47 silencing using sh-HSP47 adenovirus transfection(P<0.01).Expression levels of collagen I and III within the blebs were significantly reduced in the absence of HSP47(P<0.01).Moreover,the protein levels of TGF-β1,p-Smad2/3,and p-p38 were dramatically inhibited after treatment with sh-HSP47(P<0.01).CONCLUSION:The inhibitory effects of HSP47 knockdown on scarring after GFS have the potential to be an efficacious therapeutic option for the treatment of conjunctival bleb scarring.

Heat shock protein 90 promotes RNA helicase DDX5 accumulation and exacerbates hepatocellular carcinoma by inhibiting autophagy

Objective:Hepatocellular carcinoma(HCC),the main type of liver cancer,has a high morbidity and mortality,and a poor prognosis.RNA helicase DDX5,which acts as a transcriptional co-regulator,is overexpressed in most malignant tumors and promotes cancer cell growth.Heat shock protein 90(HSP90)is an important molecular chaperone in the conformational maturation and stabilization of numerous proteins involved in cell growth or survival.Methods:DDX5 m RNA and protein expression in surgically resected HCC tissues from 24 Asian patients were detected by quantitative real-time PCR and Western blot,respectively.The interaction of DDX5-HSP90 was determined by molecular docking,immunoprecipitation,and laser scanning confocal microscopy.The autophagy signal was detected by Western blot.The cell functions and signaling pathways of DDX5 were determined in 2 HCC cell lines.Two different murine HCC xenograft models were used to determine the function of DDX5 and the therapeutic effect of an HSP90 inhibitor.Results:HSP90 interacted directly with DDX5 and inhibited DDX5 protein degradation in the AMPK/ULK1-regulated autophagy pathway.The subsequent accumulation of DDX5 protein induced the malignant phenotype of HCC by activating theβ-catenin signaling pathway.The silencing of DDX5 or treatment with HSP90 inhibitor both blocked in vivo tumor growth in a murine HCC xenograft model.High levels of HSP90 and DDX5 protein were associated with poor prognoses.Conclusions:HSP90 interacted with DDX5 protein and subsequently protected DDX5 protein from AMPK/ULK1-regulated autophagic degradation.DDX5 and HSP90 are therefore potential therapeutic targets for HCC.

Heat shock protein 70 antisense oligonucleotide inhibits cell growth and induces apoptosis in human gastric cancer cell line SGC-7901

AIM: Heat shock protein (HSP)70 is over-expressed in human gastric cancer and plays an important role in the progression of this cancer. We investigated the effects of antisense HSP70 oligomer on human gastric cancer cell line SGC-7901, and its potential role in gene therapy for this cancer.METHODS: Human gastric cancer cell line SGC-7901 was treated in vitro with various concentrations of antisense HSP70 oligonucleotides at different intervals. Growth inhibition was determined as percentage by trypan blue dye exclusion test. Extracted DNA was electrophoresed on agarose gel, and distribution of cell cycle and kinetics of apoptosis induction were analyzed by propidium iodide DNA incorporation using flow cytometry, which was also used to detect the effects of antisense oligomer pretreatment on the subsequent apoptosis induced by heat shock in SGC-7901 cells. Proteins were extracted for simultaneous measurement of HSP70 expression level by SDS-PAGE Western blotting.RESULTS: The number of viable cells decreased in a doseand time-dependent manner, and ladder-like patterns of DNA fragments were observed in SGC-7901 cells treated with antisense HSP70 oligomers at a concentration of 10 μmol/L for 48 h or 8 μmol/L for 72 h, which were consistent with inter-nucleosomal DNA fragmentation. Flow cytometric analysis showed a dose- and time-dependent increase in apoptotic rate by HSP70 antisense oligomers. This response was accompanied with a decrease in the percentage of cells in the G1 and S phases of the cell cycle, suggesting inhibition of cell proliferation. In addition, flow cytometry also showed that pretreatment of SGC-7901 cells with HSP70 antisense oligomers enhanced the subsequent apoptosis induced by heat shock treatment. Western blotting demonstrated that HSP70 antisense oligomers inhibited HSP70 expression, which preceded apoptosis, and HSP70 was undetectable at the concentration of 10 μmol/L for 48 h or 8 μmol/L for 72 h.CONCLUSION: Antisense HSP70 oligomers can abrogate HSP70 expression in SGC-7901 cells, which may in turn induce apoptosis and inhibit cell proliferation, conversely suggesting that HSP70 is required for the proliferation and survival of human gastric cancer cells under normal conditions.

Advance in Research on Biological Function and TranscriptionalControl of Heat Shock Proteins

The regulation of heat shock transcription factor to heat shock protein expression and the newest knowledge about the effect of heat shock protein on aging,immune response and the balance of cell survival and apoptosis are summarized in the paper.

Potential involvement of heat shock proteins in pancreaticduodenal homeobox-1-mediated effects on the genesis of gastric cancer: A 2D gel-based proteomic study

AIM To identify functional proteins involved in pancreaticduodenal homeobox-1(PDX1)-mediated effects on gastric carcinogenesis.METHODS A PDX1-overexpressed model was established by transfecting gastric cancer cell line SGC7901 with pcDNA3.1(+)-PDX1 vector(SGC-PDX1). Transfection with empty pcDNA3.1 vector(SGC-pcDNA) served as control. Comparative protein profiles of the two groups were analyzed by two-dimensional electrophoresis basedproteomics(2 DE gel-based proteomics). The differential proteins identified by 2 DE were further validated by qRTPCR and immunoblotting. Finally, co-immunoprecipitation was used to determine any direct interactions between PDX1 and the differential proteins.RESULTS2 DE gel proteomics identified seven differential proteins in SGC-PDX1 when compared with those in SGC-pcDNA. These included four heat shock proteins(HSPs; HSP70 p1 B, HSP70 p8, HSP60, HSP27) and three other proteins(ER60, laminin receptor 1, similar to epsilon isoform of 14-3-3 protein). Immunoblotting validated the expression of the HSPs(HSP70, HSP60, HSP27). Furthermore, their expressions were lowered to 80%, 20% and 24%, respectively, in SGC-PDX1, while PDX1 exhibited a 9-fold increase, compared to SGC-pcDNA. However, qRT-PCR analysis revealed that mRNA levels of the HSP s were increased in SGC-PDX1, suggesting that the expression of the HSP s was post-translationally regulated by the PDX1 protein. Finally, co-immunoprecipitation failed to identify any direct interaction between PDX1 and HSP70 proteins.CONCLUSION This study demonstrates the potential involvement of HSPs in PDX1-mediated effects on the genesis of gastric cancer.

Expression profiles of two small heat shock proteins and antioxidant enzyme activity in Mytilus galloprovincialis exposed to cadmium at environmentally relevant concentrations

Small heat shock proteins encompass a widespread but diverse class of proteins, which play key roles in protecting organisms from various stressors. In the present study, the full-length cDNAs of two small heat shock proteins （MgsHSP22 and MgsHSP24.1） were cloned from Mytilus galloprovincialis, which encoded peptides of 181 and 247 amino acids, respectively. Both MgsHSP22 and MgsHSP24.1 were detected in all tissues examined by real-time PCR, with the highest expression being observed in muscle and gonad tissues. The real-time PCR results revealed that Cd significantly inhibited MgsHSP22 expression at 24 h and MgsHSP24.1 at 24 and 48 h under 5 ug/L Cd2＋ exposure. MgsHSP24.1 expression was also significantly inhibited after 50 ug/L Cd2＋ exposure for 48 h. With regard to antioxidant enzymes, increased GPx and CAT activity were detected under Cd2＋ stress （5 and 50 ug/L）, while no significant difference in SOD activity was observed throughout the experiment. Overall, both MgsHsps and antioxidant enzymes revealed their potential as Cd stress biomarkers in M. galloprovincialis.

Cryopreservation-induced decrease in heat-shock protein 90 in human spermatozoa and its mechanism

<abstract>Aim: To study the protein changes of spermatozoa associated with sperm motility during sperm cryopreservation and its mechanism. Methods: In 18 healthy men, the seminal sperm motility and HSP90 levels were studied before and after cryopreservation using SDS-PAGE, Western blotting and computerized image analysis. Results: The sperm motility declined significantly after cryopreservation (P<0.01). The average grey level and the integrated grey level of sperm HSP90 before cooling were 34.1±3.2 and 243.0±21.6, respectively, while those after thawing were 23.2±2.5 and 105.7±28.5, respectively. Both parameters were decreased significantly (P<0.01). No HSP90 was found in the seminal plasma before and after cryopreservation. Conclusion: HSP90 in human spermatozoa was decreased substantially after cryopreservation. This may result from protein degradation, rather than leakage into the seminal plasma.

Polaprezinc protects human colon cells from oxidative injury induced by hydrogen peroxide:Relevant to cytoprotective heat shock proteins

AIM： To investigate the effect of polaprezinc on cellular damage induced by hydrogen peroxide （H202） in human colon CaCo2 cells. METHODS： CaCo2 cells were treated with polaprezinc （10-100 pmol/L） for 6 h. After polaprezinc treatment, the cells were incubated with H202 （20μmol/L） for 1 h. Cell viability was measured by MTT assay. Western blot analysis for heat shock protein （HSP） 27 and HSP72 in the cells was performed. Moreover, cells were pretreated with quercetin （200 μmol/L）, an inhibitor of HSP synthesis, 2 h before polaprezinc treatment, and cell viability and the expression of HSP27 and 72 were assessed in these cells. RESULTS： Polaprezinc significantly protected CaCo2 cells from cell damage induced by H2O2, and up-regulated the expressions of HSP27 and HSP72 in the cells （10, 30 and 100 pmol/L of polaprezinc; 35.0% ± 7.7%, 58.3% ± 14.6% and 64.2% ± 8.2%, respectively. P 〈 0.01 versus polaprezinc-nontreated cells; 6.0% ± 4.4%）. Quercetin inhibited the up-regulation of HSP27 and HSP72 by polaprezinc and diminished the protective effect of polaprezinc against H2O2-caused injury in the cells. CONCLUSION： Polaprezinc is a useful therapeutic agent for treatment of colitis and its effects depend on the function of cytoprotective HSP in colon.

Involvement of heat shock proteins in gluten-sensitive enteropathy

Gluten-sensitive enteropathy,also known as coeliac disease(CD),is an autoimmune disorder occurring in genetically susceptible individuals that damages the small intestine and interferes with the absorption of other nutrients.As it is triggered by dietary gluten and related prolamins present in wheat,rye and barley,the accepted treatment for CD is a strict gluten-free diet.However,a complete exclusion of gluten-containing cereals from the diet is often difficult,and new therapeutic strategies are urgently needed.A class of proteins that have already emerged as drug targets for other autoimmune diseases are the heat shock proteins(HSPs),which are highly conserved stress-induced chaperones that protect cells against harmful extracellular factors.HSPs are expressed in several tissues,including the gastrointestinal tract,and their levels are significantly increased under stress circumstances.HSPs exert immunomodulatory effects,and also play a crucial role in the maintenance of epithelial cell structure and function,as they are responsible for adequate protein folding,influence the degradation of proteins and cell repair processes after damage,and modulate cell signalling,cell proliferation and apoptosis.The present review discusses the involvement of HSPs in the pathophysiology of CD.Furthermore,HSPs may represent a useful therapeutic target for the treatment of CD due to the cytoprotective,immunomodulatory,and anti-apoptotic effects in the intestinal mucosal barrier.

The Role of Heat Shock Proteins in Mammary Neoplasms: A Brief Review

Research into heat shock proteins (HSPs) for the clinical management of tumours has intensified as new evidence shows they can be used as biomarkers in carcinogenesis and are related to poor prognosis in some cancer types. Members of small HSP, HSP70 and HSP90 families have been studied extensively in breast cancer. This article reviews current understanding of the role of HSP and HSF-1 (Heat shock factor 1) expression in human breast cancer and looks at its potential diagnostic, prognostic and therapeutic value. The exciting progress that has been made using HSP 90 inhibitors in breast cancer treatment is examined and the results of preliminary studies on the expression of stress proteins in the animal model canine mammary tumours are also presented.

Heat shock protein 90 is a potential therapeutic target for ameliorating skeletal muscle abnormalities in Parkinson's disease

Previous studies have confirmed that heat shock protein 90 overexpression can lead to dopami- nergic neuronal death. This study was designed to further investigate what effects are produced by heat shock protein 90 after endurance exercise training. Immunohistochemistry results showed that exercise training significantly inhibited heat shock protein 90 overexpression in the soleus and gastrocnemius in Parkinson＇s disease rats, which is a potential therapeutic target for ameliorating skeletal muscle abnormalities in Parkinso^s disease.

Heat shock and other apoptosis-related proteins as therapeutic targets in prostate cancer

Defects within apoptotic pathways have been implicated in prostate cancer （PCa） tumorigenesis, metastatic progression and treatment resistance. A hallmark of cancers is the ability to derail apoptosis by inhibiting the apoptotic signal, reducing the expression of apoptotic proteins and/or amplifying survival signals through increased production of antiapoptotic molecule. This review describes associations between heat shock proteins （HSPs） and the human androgen receptor （AR）, the role of HSPs and other stress-induced proteins in PCa development and emerging strategies in targeting these protective proteins to treat PCa.

Effect of Jianpiyiqi Prescription on the Expression of Heat Shock Proteins in Acetic Acid-induced Chronic Gastric Ulcer Rats

To investigate the effect of Jianpiyiqi prescription on the expression of heat shock proteins and the changes of HSPs in gastric ulcerated rats, the rat model of chronic gastric ulcer was induced by acetic acid. The SABC immunohistochemical method was used to observe HSP70 of mucosa around the gastric ulcer. Imaging analysis was performed. Western dot blot was used to detect HSPs contents in the plasma and gastric mucosal homogenate in each group. The results showed that HSP70 contents of the mucosa around the gastric ulcer in the model group and ranitidine treated group were increased as compared with control group . Jianpiyiqi could increase the expression of HSP70 of the mucosa around the gastric ulcer further as compared with that in the model group and ranitidine treated group . The HSP70 contents in the serum and mucosa in the model group and ranitidine treated group were increased as compared with control group ( P <0.01, P <0 05 respectively). HSP70 of serum and mucosa in the Jianpiyiqi treated group was higher than in the model group and ranitidine treated group ( P <0.05, P <0.01 respectively).It was concluded that HSP might play a role in the process of pathophysiology of gastric ulcer. Jianpiyiqi could enhance gastric ulcer healing through the protective mechanism of HSPs.

Study of Heat Shock Protein HSP90α，HSP70，HSP27 mRNA Expression in Human Acute Leukemia Cells

The expression of three heat shock proteins (HSPs)-HSP90, HSP70,HSP27 in cells obtained from 22 patients with leukemia, K562 erythroleukemia cell line, and normal blood cells was observed by means of RNA dot blot analysis.The results showed that the expression of the HSP27 gene was enhanced in 4 cases of acute lymphoid leukemia (ALL), 7 cases of acute nonlymphoid leukemia (ANLL) and 2 cases of myelodysplastic syndrome (MDS) as compared with that of the normal blood cells, yet there was no significant difference in the HSP27 expression between the ALL and ANLL cells. The expression of HSP70 in all the 5 ALL and ANLL patients was much lower than that of the normal subjects, except 1 case of ALL and 1 case of MDS, in which the expression was obviously enhanced. All the cases including 11 ANLL, 5 ALL and 1 MDS had higher HSP90α expression than the normal subjects. The enhanced expression of HSP90α in leukemia cells may be associated with the active and indefinite proliferation of leukemia cells. Our results also suggest that the high expression of the HSP27gene may not be confined to a specific type of acute leukemia.