Expression of HSP-28 and three HSP-70 genes during the development and decay of thermotolerance in leukemic and nonleukemic human tumors.

Leukemic cells appear to develop less thermotolerance and then to lose their thermotolerance more rapidly than do other tumor cell lines. The reason for this phenomenon is not known. After heat shock (or other environmental stresses), mammalian cells preferentially synthesize a set of proteins known as heat shock proteins (HSPs). HSP-28 and the various isoforms of HSP-70 have been suggested as being responsible for the development of thermotolerance. In these studies, we have attempted to determine by their expression with HSPs positively correlate with the development and decay of thermotolerance and whether the expression of these genes could explain the differing thermotolerance response observed between leukemic and nonleukemic tumor cells. Polymerase chain reaction was used to detect the expression of HSP-28 and several HSP-70 genes. Our data indicate that the expression of all three heat-inducible HSP-70 genes, 70A (Hunt and Morimoto, Proc. Natl. Acad. Sci. USA, 82: 6455-6459, 1985), 70B (Voellmy et al., Proc. Natl. Acad. Sci. USA, 82: 4949-4953, 1985), and 70B' (Leung et al., Biochem J., 267: 125-132, 1990) correlate with the development and decay of thermotolerance in nonleukemic tumor cell lines after heat or arsenite treatment. HSP-28 (Hickey et al., Nucleic Acids Res., 4: 4127-4145, 1986) failed to correlate with thermotolerance development; it was not induced after 45 degrees C primary heat shock. In leukemic cells, however, none of the HSPs were induced for extended periods of time. The lack of coordinate expression of HSP genes in cells of myeloid origin may explain the poor induction and maintenance of thermotolerance that is observed in these cells.     

Expression of heat shock protein 70 and p53 in human lung cancer

Bronchial biopsies of 21 patients with lung cancer were analyzed by Western blot for stress protein HSP70 and p53 proteins. Squamous carcinoma was the most common type found. The p53 protein was detectable in 14 cases. The HSP70 was detectable in 17 and overexpressed in 9 patients. Eleven patients showed positivity for both protein expressions, however no statistical significance was found (Kappa's test, p>0.05). Specific associations were not observed for HSP70 overexpression and p53 detection that could be related to clinical finds or tabagism. Our results indicate that the stress protein HSP70 is detectable and may be involved in the tumor development.     

阴茎癌组织中热休克蛋白70表达与人乳头瘤病毒感染的关系

目的探讨热休克蛋白70(HSP70)表达与人乳头瘤病毒(HPV)感染的关系. 方法用免疫组化和原位PCR技术对78例阴茎癌组织进行检测.结果阴茎癌组织中HSP70阳性表达率为 61.5%(48/78),明显高于对照组的11.5%(P＜0.01),而与癌旁非典型增生组织中的表达无明显差异( P＞0.05).阴茎癌组织中HPV DNA阳性率为 69.2%(54/78), 54例HPV DNA阳性组织中有38例(70.4%)HSP70表达阳性,高于HPV DNA阴性组织的表达率(41.7%,P＜0.05). 结论 HSP70与阴茎癌的发生发展有密切关系,HSP70的表达增高可能与HPV16和18的感染有关.     

热休克对人胶质瘤热休克蛋白70表达水平的影响

目的:应用热休克人胶质瘤细胞的方法,观察热诱导热休克蛋白70(heatshockprotein70,HSP70)在人胶质瘤细胞的表达。方法:经43℃热处理2h的人胶质瘤细胞,应用半定量逆转录聚合酶链反应(RTPCR)及免疫组化技术检测HSP70mRNA及蛋白的表达情况。结果:热休克蛋白人胶质瘤细胞表达阳性率为(39.40±14.40)%,对照组为(8.50±4.60)%及HSP70mRNA表达光密度值为0.23±0.05,对照组为0.13±0.03与内参照βactin比值经单因素方差分析q检验显示与对照组相比有明显的升高。结论:热休克的方法可以明显诱导人胶质瘤细胞HSP70的表达。     

Heat sensitivity, thermotolerance, and profile of heat shock protein synthesis of human myelogenous leukemias

In anticipation of using single or fractionated hyperthermia treatment in ex vivo purging of leukemic bone marrow in the clinic, we have compared the hyperthermic sensitivity, kinetics of thermotolerance, and heat-shock protein synthesis in three human myelogenous leukemic cell lines. In terms of heat sensitivity, the chronic myelogenous leukemic cell line K562 was found to be the most resistant. The Dos of the 43, 44, and 45 degrees C heat survival curves were 22, 13, and 6 min, respectively. HL-60 and KG-1, both acute myelogenous leukemic lines, however, were found to be several fold more sensitive to the cytotoxic effects of heat. The Dos of the 43, 44, and 45 degrees C heat survival curves for HL-60 were 7.6, 5.6, and 2 min and for KG-1 were 5.7, 4.5, and 1.7 min, respectively. All cell lines developed thermotolerance. However, K562 developed more tolerance which lasted for longer times. For K562 cells at priming heat doses of 45 degrees C/10 min, 42 degrees C/2 h, or 41 degrees C/2 h thermotolerance was maximum at 4 to 6 h and began to decay at 24 h. HL-60 and KG-1 cells showed some thermotolerance at the priming doses of 45 degrees C/5 min or 42 degrees C/30 min and had fully decayed by 24 h. K562 cells synthesized Mr 70,000 heat shock protein for over 24 h following the 45 degrees C/10 min heat shock, while HL-60 and KG-1 synthesized Mr 70,000 heat shock protein for 2-4 h for the same amount of cell kill. These studies suggest that most human leukemias may be extremely sensitive to the cytotoxic effects of heat, and in vitro purging of leukemias from bone marrow specimens by heat needs to be further studied both by in vitro and in vivo model systems.     

热休克蛋白70在人胃癌中呈过度表达

目的：研究热休克蛋白７０（ＨＳＰ－７０）在人胃癌组织中的表达。方法：应用抗人ＨＳＰ７０单克隆抗体对１９０例手术及胃镜活检胃癌及非癌胃粘膜病变石蜡标本,以免疫组织化学ＡＢＣ法检测ＨＳＰ７０的表达。结果：ＨＳＰ７０在胃癌、慢性浅表性胃炎、肠上皮化生及不典型增生组织中的阳性率分别为７３％、３２．５％、６６％及７２％;地表达率分别为５６％、５．８％、２９．２％及３３．３３％。ＨＳＰ７０在肠上皮化生、不典型     

Expression of heat shock protein 70 and c-myc protein in human breast cancer: an immunohistochemical study.

The major heat shock protein, HSP70, protects cells from a variety of stressful stimuli, while c-myc protein allegedly stimulates the expression of HSP70 by transacting on the HSP70 promotor. The present study was aimed at correlating the expression of HSP70 with that of c-myc protein in benign and malignant breast lesions. Indirect immunoperoxidase and immunoblotting techniques using monoclonal antibodies were employed. Fresh frozen sections were prepared from five fibroadenomas and 59 breast carcinomas. Immunohistochemically, both substances were localized in the nuclei and/or cytoplasm of normal and neoplastic epithelial cells. The stromal cells were positive for c-myc protein but negative for HSP70. The expressions of HSP70 and c-myc protein were comparable to each other in the malignant cells from 37 (63%) carcinomas. In 17 (29%) carcinomas, c-myc protein expression predominated over that of HSP70, whereas in five (8%) carcinomas, HSP70 was predominant. Carcinomas with high-grade nuclear atypia often showed negative HSP70 staining, whereas tumors with nuclear HSP70 localization tended to accompany lower-grade nuclear atypia. A similar relation was also observed between c-myc protein expression and nuclear atypia of the tumor. All five fibroadenomas and most of the non-neoplastic epithelial cells adjacent to cancer showed strong reactivities with both substances. Immunoblot analysis for HSP70 revealed a clear, single band in the extract of tumors with strong HSP70 staining, but no, or only faint, bands were seen in the extract of immunohistochemically HSP70-negative carcinomas. The discrepancy between the expressions of each substance in a certain percentage of breast carcinomas may suggest the presence of HSP70 production mechanisms other than the c-myc protein-triggered promotor pathway.     

Heat sensitivity of human cancer cells and abnormal expression of heat shock protein 70

We investigated the heat-sensitivities of human normal and cancer cells at different growth conditions in vitro. We found no difference in sensitivities between normal and cancer cells at growing condition. Normal cells at confluence, however, reduced their heat-sensitivity 5-6 times than at growing condition, while the cancer cells did not. Analysis by monoclonal antibodies for hsp 70 showed the differential staining patterns between normal and cancer cells after treatment with heat (43 degrees C for 2 hours). The constitutive expression levels of hsp 70 in cancer cells were 2-3 times higher than those in normal cells. However, the degrees of hsp 70 induction by heat shock treatment in cancer cells were lower than those in normal cells. These results suggest that cancer cells may be abnormal in expression mechanisms of hsp 70.     

FLT3 expressing leukemias are selectively sensitive to inhibitors of the molecular chaperone heat shock protein 90 through destabilization of signal transduction-associated kinases.

PURPOSE: We conducted studies to evaluate the hypothesis that FLT3 is a client of heat shock protein (Hsp) 90 and inhibitors of Hsp90 may be useful for therapy of leukemia. EXPERIMENTAL DESIGN: The effects of the Hsp90-inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) on cell growth, expression of signal transduction kinases, apoptosis, FLT3 phosphorylation and interaction with Hsp90 was determined in FLT3(+) human leukemias. RESULTS: We found that FLT3 is included in a multiprotein complex that includes Hsp90 and p23. 17-AAG inhibited FLT3 phosphorylation and interaction with Hsp90. FLT3(+) leukemias were significantly more sensitive to the Hsp90 inhibitors 17-AAG and Herbimycin A in cell growth assays than FLT3-negative leukemias. Cells transfected with FLT3 became sensitive to 17-AAG. Cell cycle inhibition and apoptosis were induced by 17-AAG. Cells with constitutive expression of FLT3, as a result of internal tandem duplication, were the most sensitive; cells with wild-type FLT3 were intermediate in sensitivity, and FLT3-negative cells were the least sensitive. 17-AAG resulted in reduced cellular mass of FLT3, RAF, and AKT. The mass of another Hsp, Hsp70, was increased. The expression level of MLL-AF4 fusion protein was not reduced by 17-AAG in human leukemia cells. CONCLUSIONS: FLT3(+) leukemias are sensitive to 17-AAG and Herbimycin A. 17-AAG inhibits leukemia cells with either FLT3-internal tandem duplication or wild-type FLT3, in part through destabilization of client kinases including FLT3, RAF, and AKT. 17-AAG is potentially useful for therapy of FLT3-expressing leukemias, including the mixed lineage leukemia fusion gene leukemias.     

Heat shock and heat shock protein 70i enhance the oncolytic effect of replicative adenovirus.

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 replication restriction on an avian adenovirus (Ad) in a human lung cancer cell line. Therefore, we hypothesized that heat shock and overexpression of heat shock protein (hsp) would support the oncolytic effect of a replication-competent human Ad. To this end, we tested the oncolytic and burst kinetics of a replication-competent Ad after exposure to heat shock or to inducible hsp 70 overexpression by a replication-deficient Ad (Adhsp 70i). Heat-shock resulted in augmentation of Ad burst and oncolysis while decreasing total intracellular Ad DNA. Overexpression of hsp 70i also enhanced Ad-mediated oncolysis but did not decrease intracellular Ad DNA levels. We conclude that heat shock and Adhsp 70i enhance the Ad cell-killing potential via distinct mechanisms. A potential therapeutic implication would be the use of local hyperthermia to augment oncolysis by increasing the burst of replication-competent Ad. The role of hsp in Ad-mediated oncolysis should be additionally explored.     

Expression of transforming growth factor alpha and epidermal growth factor receptor messenger RNA in neoplastic and nonneoplastic human kidney tissue

Using Northern blot analysis, we have demonstrated that mRNA for transforming growth factor alpha (TGF-alpha) was expressed in five malignant kidney tissue specimens but was not detected in their autologous nonneoplastic homologues. In addition, the expression of epidermal growth factor (EGF) receptor mRNA in these malignant tissues was 2- to 3-fold greater than in nontransformed tissues. In two cases examined using immunohistochemistry, we were able to correlate the increased expression of the mRNA with an increase in protein expression. Since TGF-alpha is known to bind to the EGF receptor, the finding of an increased expression of both TGF-alpha and EGF receptor mRNA in kidney tumor tissue suggests that interaction between TGF-alpha and the EGF receptor may play a role in promoting transformation and/or proliferation of kidney neoplasms, perhaps by an autocrine mechanism.     

人胃癌组织中热休克蛋白70和糖调节蛋白94的表达及其意义

目的：探讨休克蛋白70（HSP70）和糖调节蛋白94（grp94）在人胃癌组织中的表达与临床病理的关系。方法：应用免疫组织化学和病理学图像分析方法研究60例人胃癌组织及其癌旁组织、发生及未发生转移的癌组织中HSP70和grp94的表达。结果：在胃癌组织中HSP70和grp94的表达明显高于癌旁组织（93.3%,81.7%vs36.7%,25.0%,P〈0.01）。HSP70和grp94在低分化和发生转移的胃癌组织中的表达明显高于非转移癌和癌旁组织（90.0%,85.0%;100%,84.6%vs36.7%,25.0%;P〈0.01）。结论：HSP70和grp94在发生转移的低分化胃癌组织和未发生转移的高分化癌组织中表达存在明显不同,可以作为胃癌的诊断或预后指标。     

The 70 kilodalton heat shock protein is an inhibitor of apoptosis in prostate cancer.

The 70 kD heat shock protein (HSP70) plays essential cellular roles in mediating intracellular protein folding and protecting cells from proteotoxic stress. This study has examined the role of HSP70 in the expression of apoptosis in prostate carcinoma cells. Apoptosis was negatively correlated with HSP70 expression in PC-3 cells heat shocked in vivo. Further experiments carried out on an in vitro reconstituted system with isolated nuclei and cytoplasm from PC-3 cells showed that purified HSP70 directly inhibits apoptosis in a dose-dependant manner. Therefore, the potential role of depletion of intracellular HSP70 was examined as a means of inducing apoptosis in PC-3 cancer cells. Depletion of HSP70 by two independent strategies, either with anti-sense oligonucleotides directed against HSP70 mRNA or with the bioflavinoid drug quercetin, led to apoptosis in the absence of stress. In addition, quercetin pre-treatment synergistically enhanced apoptosis in combination with heat shock. Thus, HSP70 plays a physiological role in tumour cells as an inhibitor of apoptosis occurring both spontaneously and after stress and is a potential target for apoptosis-based cancer therapy.