Objective: Heat shock factor 1(HSF1), a transcriptional regulator of heat shock proteins(HSPs), is an attractive therapeutic target for cancer. However, only a few HSF1 inhibitors have been identified so far.Methods: ...Objective: Heat shock factor 1(HSF1), a transcriptional regulator of heat shock proteins(HSPs), is an attractive therapeutic target for cancer. However, only a few HSF1 inhibitors have been identified so far.Methods: The mRNA and protein levels of HSF1, HSPs, cleaved PARP, and phosphorylated HSF1 were examined by real-time PCR and Western blot. Forced expression, RNA interference, and immunofluorescence assay were used for mechanistic studies.Cell viability and apoptosis were measured by WST-8 assay and flow cytometry, respectively. Xenograft studies were performed in nude mice to evaluate the effect of dorsomorphin and an HSP90 inhibitor on tumor growth.Results: Dorsomorphin suppressed multiple stimuli-induced and constitutive HSPs expression in cancer cells. Mechanistic studies revealed that dorsomorphin reduced heat-induced HSP expression independent of adenosine monophosphate activated protein kinase. Dorsomorphin reduced heat-stimulated HSF1 Ser320 phosphorylation and nuclear translocation, as well as resting nuclear HSF1 levels in cancer cells. Dorsomorphin induced cancer cell apoptosis by inhibiting HSF1 expression. A structure-activity study revealed that the 4-pyridyl at the 3-site of the pyrazolo [1, 5-a]pyrimidine ring is critical for the anti-HSF1 activities of dorsomorphin. Dorsomorphin sensitized cancer cells to HSP90 and proteasome inhibitors and inhibited HSP70 expression induced by these inhibitors in vitro. In tumor-bearing nude mice, dorsomorphin enhanced HSP90 inhibitor-induced cancer cell apoptosis, tumor growth inhibition, and HSP70 expression.Conclusions: Dorsomorphin is an HSF1 inhibitor. It induces cancer cell apoptosis, sensitizes cancer cells to both HSP90 and proteasome inhibitors, and suppresses HSP upregulation by these drugs, which may prevent the development of drug resistance.Hence, dorsomorphin and its derivates may serve as potential precursors for developing drugs against cancer.展开更多
Heat shock proteins (HSPs) serve to correct proteins’ conformation, send the damaged proteins for degradation (quality control function). Heat shock factors (HSFs) are their transcription factors. The protein complex...Heat shock proteins (HSPs) serve to correct proteins’ conformation, send the damaged proteins for degradation (quality control function). Heat shock factors (HSFs) are their transcription factors. The protein complexes mTOR1 and 2 (with the same core mTOR), the phosphoinositide-dependent protein kinase-1 (PDK1), the seine/threonine-specific protein kinase (Akt), HSF1, plus their associated proteins form a network participating in protein synthesis, bio-energy generation, signaling for apoptosis with the help of HSPs. A cancer cell synthesizes proteins at fast rate and needs more HSPs to work on quality control. Shutting down this network would lead to cell death. Thus inhibitors of mTOR (mTORI) and inhibitors of HSPs (HSPI) could drive cancer cell to apoptosis—a “passive approach”. On the other hand, HSPs form complexes with polypeptides characteristic of the cancer cells;on excretion from the cell, they becomes antigens for the immunity cells, eventually leading to maturation of the cytotoxic T cells, forming the basic principle of preparing cancer-specific, person-specific vaccine. Recent finding shows that HSP70 can penetrate cancer cell and expel its analog to extracellular region, giving the hope to prepare a non-person-specific vaccine covering a variety of cancers. Activation of anti-cancer immunity is the “active approach”. On the other hand, mild hyperthermia, with increase of intracellular HSPs, has been found to activate the immunity response, and demonstrate anti-cancer effects. There are certain “mysteries” behind the mechanisms of the active and passive approaches. We analyze the mechanisms involved and provide explanations to some mysteries. We also suggest future research to improve our understanding of these two approaches, in which HSPs play many roles.展开更多
目的:探讨热休克蛋白70结合蛋白1(heat shock protein 70 binding protein 1,HspBP1)能否促进内源性突变亨廷顿蛋白(mutant Huntingtin,mHTT)在星形胶质细胞中积聚,并确定其是否能够介导病理性损伤。方法:在GFAP-HD转基因小鼠的星形胶...目的:探讨热休克蛋白70结合蛋白1(heat shock protein 70 binding protein 1,HspBP1)能否促进内源性突变亨廷顿蛋白(mutant Huntingtin,mHTT)在星形胶质细胞中积聚,并确定其是否能够介导病理性损伤。方法:在GFAP-HD转基因小鼠的星形胶质细胞中过表达HspBP1,通过免疫染色和蛋白印迹法检测mHTT和神经病理相关蛋白表达水平,并通过行为学实验观察小鼠的运动功能水平。结果:GFAP-HD转基因小鼠短期内即出现星形胶质细胞中的mHTT积聚以及运动功能障碍,但并未出现星形胶质细胞活化和神经元损伤。结论:HspBP1能够通过促进星形胶质细胞内源性mHTT积聚介导病理性损伤,但mHTT在神经元和星形胶质细胞中共同表达可能是神经元显著变性的必需条件。展开更多
基金supported by grants from the National Key Research and Development Program of China (Grant No.2017YFC1601702)China Postdoctoral Science Foundation (Grant No.2011M500825)
文摘Objective: Heat shock factor 1(HSF1), a transcriptional regulator of heat shock proteins(HSPs), is an attractive therapeutic target for cancer. However, only a few HSF1 inhibitors have been identified so far.Methods: The mRNA and protein levels of HSF1, HSPs, cleaved PARP, and phosphorylated HSF1 were examined by real-time PCR and Western blot. Forced expression, RNA interference, and immunofluorescence assay were used for mechanistic studies.Cell viability and apoptosis were measured by WST-8 assay and flow cytometry, respectively. Xenograft studies were performed in nude mice to evaluate the effect of dorsomorphin and an HSP90 inhibitor on tumor growth.Results: Dorsomorphin suppressed multiple stimuli-induced and constitutive HSPs expression in cancer cells. Mechanistic studies revealed that dorsomorphin reduced heat-induced HSP expression independent of adenosine monophosphate activated protein kinase. Dorsomorphin reduced heat-stimulated HSF1 Ser320 phosphorylation and nuclear translocation, as well as resting nuclear HSF1 levels in cancer cells. Dorsomorphin induced cancer cell apoptosis by inhibiting HSF1 expression. A structure-activity study revealed that the 4-pyridyl at the 3-site of the pyrazolo [1, 5-a]pyrimidine ring is critical for the anti-HSF1 activities of dorsomorphin. Dorsomorphin sensitized cancer cells to HSP90 and proteasome inhibitors and inhibited HSP70 expression induced by these inhibitors in vitro. In tumor-bearing nude mice, dorsomorphin enhanced HSP90 inhibitor-induced cancer cell apoptosis, tumor growth inhibition, and HSP70 expression.Conclusions: Dorsomorphin is an HSF1 inhibitor. It induces cancer cell apoptosis, sensitizes cancer cells to both HSP90 and proteasome inhibitors, and suppresses HSP upregulation by these drugs, which may prevent the development of drug resistance.Hence, dorsomorphin and its derivates may serve as potential precursors for developing drugs against cancer.
文摘Heat shock proteins (HSPs) serve to correct proteins’ conformation, send the damaged proteins for degradation (quality control function). Heat shock factors (HSFs) are their transcription factors. The protein complexes mTOR1 and 2 (with the same core mTOR), the phosphoinositide-dependent protein kinase-1 (PDK1), the seine/threonine-specific protein kinase (Akt), HSF1, plus their associated proteins form a network participating in protein synthesis, bio-energy generation, signaling for apoptosis with the help of HSPs. A cancer cell synthesizes proteins at fast rate and needs more HSPs to work on quality control. Shutting down this network would lead to cell death. Thus inhibitors of mTOR (mTORI) and inhibitors of HSPs (HSPI) could drive cancer cell to apoptosis—a “passive approach”. On the other hand, HSPs form complexes with polypeptides characteristic of the cancer cells;on excretion from the cell, they becomes antigens for the immunity cells, eventually leading to maturation of the cytotoxic T cells, forming the basic principle of preparing cancer-specific, person-specific vaccine. Recent finding shows that HSP70 can penetrate cancer cell and expel its analog to extracellular region, giving the hope to prepare a non-person-specific vaccine covering a variety of cancers. Activation of anti-cancer immunity is the “active approach”. On the other hand, mild hyperthermia, with increase of intracellular HSPs, has been found to activate the immunity response, and demonstrate anti-cancer effects. There are certain “mysteries” behind the mechanisms of the active and passive approaches. We analyze the mechanisms involved and provide explanations to some mysteries. We also suggest future research to improve our understanding of these two approaches, in which HSPs play many roles.
基金supported by grants from The Ministry of Science and Technology of China (2006DFB32420)The National Natural Science Foundation of China (30221003, 30670494)The "Sino-European Project on SARS Diagnostics and Antivirals" (SEPSDA) of The European Commission (003831)~~
文摘目的:探讨热休克蛋白70结合蛋白1(heat shock protein 70 binding protein 1,HspBP1)能否促进内源性突变亨廷顿蛋白(mutant Huntingtin,mHTT)在星形胶质细胞中积聚,并确定其是否能够介导病理性损伤。方法:在GFAP-HD转基因小鼠的星形胶质细胞中过表达HspBP1,通过免疫染色和蛋白印迹法检测mHTT和神经病理相关蛋白表达水平,并通过行为学实验观察小鼠的运动功能水平。结果:GFAP-HD转基因小鼠短期内即出现星形胶质细胞中的mHTT积聚以及运动功能障碍,但并未出现星形胶质细胞活化和神经元损伤。结论:HspBP1能够通过促进星形胶质细胞内源性mHTT积聚介导病理性损伤,但mHTT在神经元和星形胶质细胞中共同表达可能是神经元显著变性的必需条件。
