• Microbiology and Biotechnology Letters
• /
• v.32 no.4
• /
• pp.297-306
• /
• 2004

Heat shock proteins (HSPs) were induced in cells in the thermal stress, and the HSP90 family is one of the major classes of HSPs. Gene encoding HSPs have been characterized from various mammals and piscine. We have cloned and sequenced the HSP90 cDNA from a brain cDNA library constructed from flounder (Paralichthys oliThe result of sequence analysis shows it to be the HSP90~. The nucleotide sequence of the HSP90$\beta$ was composed of 2791 long, encoding 726 amino acid residues. The flounder hsp90$\beta$ gene showed very high sequence homology with hsp90f3 of European sea bass (96.6%), zebrafish (92.9%), Atlantic salmon (92.0%) and human (89.5%). We also constructed a phylogenetic tree based on HSP90 amino acid sequences from vertebrate species. Gene-specific primers were selected and used in RT-PCR reactions to measure the basal hsp90$\beta$ mRNA. The hsp90f3 gene is constitutively expressed at a fairly high level in all examined tissues (brain, liver, kidney, muscle, and spleen). In order to express protein of flounder hsp90$\beta$ in E. coli, we used the His-tagged pETvector. Then, the expression of flounder HSP90$\beta$ was confirmed by Western blot analysis.

• Korean Journal of Clinical Laboratory Science
• /
• v.49 no.4
• /
• pp.460-469
• /
• 2017

Heat shock proteins (HSPs) are induced as a self-defense mechanism of cells when exposed to various external stresses, such as high fever, infection, free radicals, and heavy metals. They affect the prognosis in the process of tumor formation. HSP is classified into four families: HSP27, HSP60, HSP90, and HSP100, depending on molecular weight. Heat shock protein 90 (HSP90), a molecular chaperone, plays an important role in the cellular protection against various stressful stimuli and in the regulation of cell cycle progression and apoptosis. In the present study, we assessed the differential expression of HSP90 family proteins in non-small cell lung cancer (NSCLC), and the correlation of their expression levels with clinicopathologic factors and patient survival rates. The result of this study can be summarized as follows; $HSP90{\alpha}$ showed higher expression in patients with no lymphovascular invasion (p=0.014). $HSP90{\beta}$ showed a higher expression of squamous cell carcinoma (p=0.003), and an over expression of glucose-related protein (GRP94) was significantly associated with poor differentiation (p=0.048). However, none of the HSP90 proteins showed a significant association with the survival status in patients with NSCLC. This study also indicates that $HSP90{\alpha}$ might contribute more to the carcinogenesis of NSCLC than $HSP90{\beta}$, and GRP94 and isoform selectivity should be considered when HSP90 inhibitors are studied or utilized in the treatment of NSCLC.

• BMB Reports
• /
• v.46 no.1
• /
• pp.47-52
• /
• 2013

Intestinal epithelial cell (IEC) apoptosis induced by hypoxia compromise intestinal epithelium barrier function. Both Akt and Hsp90 have cytoprotective function. However, the specific role of Akt and $Hsp90{\beta}$ in IEC apoptosis induced by hypoxia has not been explored. We confirmed that hypoxia-induced apoptosis was reduced by $Hsp90{\beta}$ overexpression but enhanced by decreasing $Hsp90{\beta}$ expression. $Hsp90{\beta}$ overexpression enhanced BAD phosphorylation and thus reduced mitochondrial release of cytochrome C. Reducing $Hsp90{\beta}$ expression had opposite effects. The protective effect of $Hsp90{\beta}$ against apoptosis was negated by LY294002, an Akt inhibitor. Further study showed that Akt phosphorylation was enhanced by $Hsp90{\beta}$, which was not due to the activation of upstream PI3K and PDK1 but because of stabilization of pAkt via direct interaction between $Hsp90{\beta}$ and pAkt. These results demonstrate that $Hsp90{\beta}$ may play a significant role in protecting IECs from hypoxia-induced apoptosis via stabilizing pAkt to phosphorylate BAD and reduce cytochrome C release.

• Journal of Pharmacopuncture
• /
• v.22 no.1
• /
• pp.28-34
• /
• 2019

Background: Breast cancer is a complex, heterogeneous disease and one of the most common malignancies in women worldwide. The efficacy of chemotherapy as an important breast cancer treatment option has been severely limited because of the inherent or acquired resistance of cancer cells. The molecular chaperone heat shock protein 90 (HSP90) upregulated in response to cellular stress is required for functions such as conformational maturation, activation and stability in more than 200 client proteins, mostly of the signaling type. In this study, the expression of HSP90 isoforms including $HSP90{\alpha}$ and $HSP90{\beta}$ in breast cancer cell lines before and after treatment with doxorubicin (DOX) was assessed. Material and Methods: The cell cytotoxicity of DOX in MDA-MB-231 and MCF-7 cell lines was determined using the MTT assay. immunofluorescence and western blotting techniques were used to determine the expression of $HSP90{\beta}$ in the cell lines before and after DOX treatment. Immunofluorescence was also conducted to ascertain the expression of $HSP90{\alpha}$. Results: The MTT assay results showed that the MDA-MB-231 cells ($IC_{50}=14.521{\mu}M$) were more sensitive than the MCF-7 cells ($IC_{50}=16.3315{\mu}M$) to DOX. The immunofluorescence results indicated that the expression of $HSP90{\alpha}$ in both cell lines decreased after exposure to DOX. The western blot and immunofluorescence analyses showed that $HSP90{\beta}$ expression decreased in the MCF-7 cells but increased in the MDA-MB-231 cells after DOX treatment. Conclusion: The obtained results suggested that $HSP90{\alpha}$ and $HSP90{\beta}$ expression levels were reduced in the MCF-7 cells after exposure to DOX. In the MDA-MB-231 cells, $HSP90{\alpha}$ expression was reduced while $HSP90{\beta}$ was found to be overexpressed following DOX treatment.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.17
• /
• pp.7113-7118
• /
• 2014

Background: HSP90 may be overexpressed in cancer cells which are greatly dependent on Hsp90 function. Geldanamycin derivative 17 allylamino-17-demethoxygeldanamycin (17-AAG) inhibits the function and expression of HSP90. 17-AAG has poor water-solubility which is a potential problem for clinical practice. In this study for improving the stability and solubility of molecules in drug delivery systems we used a ${\beta}$-cyclodextrin-17AAG complex. Materials and Methods: To assess cytotoxic effects of ${\beta}$-cyclodextrin-17AAG complexes and free 17AAG, colorimetric cell viability (MTT) assays were performed. Cells were treated with equal concentrations of ${\beta}$-cyclodextrin- 17AAG complex and free 17AAG and Hsp90 gene expression levels in the two groups was compared by real-time PCR. Results: MTT assay confirmed that ${\beta}$-cyclodextrin- 17AAG complex enhanced 17AAG cytotoxicity and drug delivery in T47D breast cancer cells. The level of Hsp90 gene expression in cells treated with ${\beta}$-cyclodextrin- 17AAG complex was lower than that of cells treated with free 17AAG (P=0.001). Conclusions: The results demonstrated that ${\beta}$-cyclodextrin- 17AAG complexes are more effective than free 17AAG in down-regulating HSP90 expression due to enhanced ${\beta}$-cyclodextrin-17AAG uptake by cells. Therefore, ${\beta}$-cyclodextrin could be superior carrier for this kind of hydrophobic agent.

• Biomedical Science Letters
• /
• v.12 no.4
• /
• pp.419-425
• /
• 2006

Phospholipase $C-{\gamma}1\;(PLC-{\gamma}1)$ is an important signaling molecule for cell proliferation and differentiation. $PLC-{\gamma}1$ contains two pleckstrin homology (PH) domains, which are responsible for protein-protein interaction and protein-lipid interaction. $PLC-{\gamma}1$ also has two Src homology (SH)2 domains and a SH3 domain, which are responsible for protein- protein interaction. To identity proteins that specifically binds to PH domain of $PLC-{\gamma}1$, we prepared and incubated the glutathione S-transferase(GST)-fused PH domains of $PLC-{\gamma}1$ with COS7 cell lysate. We found that 90 kDa protein specifically binds to PH domain of $PLC-{\gamma}1$. By matrix-assisted laser desorption ionization time of flight-mass spectrometry, the 90 kDa protein revealed to be heat shock protein (Hsp) $90{\beta}$. Hsp $90{\beta}$ is a molecular chaperone that stabilizes and facilitates the folding of proteins that are involved in cell signaling, including receptors for steroids hormones and a variety of protein kinases. To know whether Hsp $90{\beta}$ affects on $PLC-{\gamma}1$ activity, we performed $PIP_2$ hydrolyzing activity of $PLC-{\gamma}1$ in the presence of purified Hsp $90{\beta}$ in vitro. Our results show that the Hsp $90{\beta}$ dose-dependently inhibits the enzymatic activity of $PLC-{\gamma}1$ and further suggest that Hsp $90{\beta}$ regulates cell growth and differentiation via regulation of $PLC-{\gamma}1$ activity.

• Korean Journal of Poultry Science
• /
• v.43 no.2
• /
• pp.77-88
• /
• 2016

To establish a new synthetic Korean meat chicken breed, we tested $5{\times}5$ diallel cross mating experiment with domestic chicken breeds. Comparing stress responses among diallel crossed chicken breeds, we analyzed telomere length, DNA damage and expressions of heat shock protein genes (HSPs) as the markers of the stress response. The telomere length was measured by quantitative fluorescence in situ hybridization on the nuclei of lymphocytes. The expression levels of HSP-70, $HSP-90{\alpha}$ and $HSP-90{\beta}$ genes were analyzed by quantitative real-time polymerase chain reaction in lymphocytes. The DNA damage rate of lymphocytes was quantified by the comet assay known as the single cell gel electrophoresis. In results, there were significant differences in the values of the stress markers such as telomere length, HSPs and DNA damage rate, and also were significant differences in viabilities and body weights among the $5{\times}5$ diallel crossed chicken breeds. The telomere shortening rate, expression values of HSPs and DNA damage rate were significant low in W and Y crossed chickens compare to the others, but GG pure breed showed the highest values in the 25 crossed chickens. Estimating correlation coefficient, the survival rate positively correlated to telomere length, but negatively correlated to the expression levels of HSP-70, $HSP-90{\alpha}$, $HSP-90{\beta}$ genes and to the value of % DNA in tail as DNA damage rate. The expression levels of HSP-70, $HSP-90{\alpha}$ and $HSP-90{\beta}$ genes of dead chickens had significantly higher than those of survival chickens. According to the results on the stress marker analysis, it would be considered that the crossed breeds had more stress resistant than the pure breeds, and the crossed chickens with a light strain such as W or Y were relatively resistant to stress, but the crossed chickens with a heavy strain such as G, H, F were susceptible to stress.

• Korean Journal of Poultry Science
• /
• v.42 no.2
• /
• pp.157-167
• /
• 2015

We compared the degrees of stress response of 12 domestic purebred chicken strains that have been bred at National Institute of Animal Science, RDA, Korea since 1980. As a physiological marker of stress response, the expression levels of heat shock protein (HSP)-70, HSP-$90{\alpha}$, HSP-$90{\beta}$, hydroxyl-3-methyl-glutaryl coenzyme A reductase (HMGCR) genes and telomere length were measured by quantitative real-time polymerase chain reaction using the lymphocytes of 1,101 chickens. There was significant difference in HSP-70, HSP-$90{\alpha}$, HMGCR expression and telomere length among the strains. There was also significant difference in HSP-$90{\alpha}$, HSP-$90{\beta}$, and HMGCR expression between male and female chickens. Different age groups of chicken exhibited different expression levels of HSP-70, HSP-$90{\alpha}$ and telomere length. The results of the HSPs expression level suggested that, the strains of R, L and Y were highly resistant to stress, whereas the strains of S, O and W were susceptible to stress. Although the statistical differences in some of HSPs gene expression existed between genders, the HSP expression results varied in different strains that some opposed to the others, and there might be interaction between strains and genders, which conclude that there was no difference in stress response between male and female chickens. Moreover, despite of significant difference in some of HSPs expression level, it was considered that there was no difference in stress response between ages due to the inconsistent trends among HSP markers.

• Korean Journal of Clinical Laboratory Science
• /
• v.50 no.4
• /
• pp.462-469
• /
• 2018

HSP90 regulates various proteins involved in differentiation and cell survival. Levels of HSP90 tend to increase during development of squamous cell carcinoma in the head and neck including the mouth. Thus, many studies have been conducted to treat these cancers through suppression of HSP90. This study investigated the effect of two HSP90 inhibitors, geldanamycin and 17-AAG, on the proliferation, apoptosis, and invasion of human oral squamous cell carcinoma cells. Cell survival and cell cycle analyses, as well as western blot analysis, were performed with oral cancer cell lines, YD-10B and YD-38. After treatment with HSP90 inhibitors, cell proliferation was significantly inhibited. When YD-10B and YD-38 cells were treated with various concentrations of geldanamycin and 17-AAG (0, 0.1, 0.3, 1 and $10{\mu}M$) for 24 hr, the growth of YD-10B cells was markedly reduced compared to that of YD-38 cells. Thereafter, the cells were subjected to flow cytometry, which revealed G2 arrest. These results demonstrated that geldanamycin induced G2 arrest and inhibited cell proliferation through the $p-GSK-3{\beta}$ pathway in YD-10B and YD-38 cells, thus inhibiting cell survival. HSP90 inhibitors are therefore expected to have a therapeutic effect on various cancer cell lines.

• Journal of Life Science
• /
• v.32 no.3
• /
• pp.241-248
• /
• 2022

NF-κB acts as a critical transcription factor in inflammation and innate immunity, and it is also closely involved in cell survival and tumorigenesis via induction of anti-apoptotic genes. In these processes, NF-κB cooperates with multiple other signaling molecules and pathways, and although many studies have demonstrated that Hsp90 regulates NF-κB activity, the exact mechanism is unclear. In this study, we investigated the relationship between Hsp90 and IKKγ in the regulation of NF-κB using expression plasmids of IKK complex components. Wild-type and deletion mutants of IKKγ were expressed together with Hsp90, and the combined regulatory effect of Hsp90 and IKKγ on NF-κB activation was assayed. The results show that Hsp90 activates NF-κB by promoting the phosphorylation and degradation of IκBα and that activation of NF-κB by NIK and LPS was increased by Hsp90. IKKγ elevated the effect of Hsp90 on NF-κB activation by increasing phosphorylation and degradation of IκBα. The positive regulation on NF-κB by Hsp90 and IKKγ was also proved in analysis with IKKβ-EE, the constitutively active form of IKKβ. In experiments with the deletion mutants of IKKγ, the N-terminal IKKβ binding domain, C-terminal leucine zipper, and zinc finger domains of IKKγ were found not necessary for the positive regulation of NF-κB activity. Additionally, the expression of pro-inflammatory cytokines was synergistically elevated by Hsp90 and IKKγ. These results indicate that inhibiting the interaction between Hsp90 and IKKγ is a possible strategic method for controlling NF-κB and related diseases.