The HSP90AA1 Gene Is Involved in Heat Stress Responses and Its Functional Genetic Polymorphism Are Associated with Heat Tolerance in Holstein Cows

As the stress-inducible isoform of the Heat Shock Protein 90 (HSP90), the HSP90AA1 gene encodes HSP90α and plays an important role in heat stress (HS) response. Therefore, this study aimed to investigate the role of the HSP90AA1 gene in cellular responses during HS and to identify functional single nucleotide polymorphisms (SNP) associated with thermotolerance in Holstein cattle. For the in vitro validation experiment of acute HS, cells from the Madin-Darby bovine kidney (MDBK) cell line were exposed to 42°C for 1 h, and various parameters were assessed, including cell apoptosis, cell autophagy, and the cellular functions of HSP90α by using its inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG). Furthermore, the polymorphisms identified in the HSP90AA1 gene and their functions related to HS were in vitro validated. Acute HS exposure induced cell apoptosis, cell autophagy, and upregulated expression of the HSP90AA1 gene. Inhibition of HSP90α by 17-AAG treatment had a significant effect on the expression of the HSP90α protein (P < 0.05) and increased cell apoptosis. However, autophagy decreased in comparison to the control treatment when cells were exposed to 42°C for 1 h. Five SNPs identified in the HSP90AA1 gene were significantly associated with rectal temperature (RT; P < 0.05) and respiration score (RS; P < 0.05) in Holstein cows, in which the rs109256957 SNP is located in the 3' untranslated region (3' UTR). Furthermore, we demonstrated that the 3' UTR of HSP90AA1 is a direct target of bta-miR-1224 by cell transfection with exogenous miRNA mimic and inhibitor. The luciferase assays revealed that the SNP rs109256957 affects the regulation of bta-miR-1224 binding activity and alters the expression of the HSP90AA1 gene. Heat stress-induced HSP90AA1 expression maintains cell survival by inhibiting cell apoptosis and increasing cell autophagy. The rs109256957 SNP located in the 3' UTR region is a functional variation and it affects the HSP90AA1 expression by altering its binding activity with bta-miR-1224, thereby associating with the physiological parameters of Holstein cows.

Apigenin exerts anti-cancer effects in colon cancer by targeting HSP90AA1

Apigenin, a flavonoid, has shown early promise in colon cancer (CC); thus, exploring potential mechanisms of Apigenin is obligatory. In this study, shared targets of Apigenin and CC were identified through online tools, which were then subjected to functional enrichment analyses, Gene Ontology and KEGG. Further, the protein-protein interaction network of the shared targets was developed (via STRING). The top targets of Apigenin in CC were identified by molecular docking; further investigated for differential gene and protein expression in CC and their influence on CC patient survival (using TCGA data). Out of 13 hub genes, the top 3 targets (HSP90AA1, MMP9, PTGS2) were selected based on docking score. Their expression was significantly elevated and related to poor overall survival in CC (except PTGS2). Molecular dynamics simulation further validated protein-ligand interactions and divulged HSP90AA1 as the best target of Apigenin in CC. Finally, the anti-cancer effects of Apigenin and its major metabolite, luteolin, were investigated in CC, which is involved in the cytotoxicity of CC cells (COLO-205) by reducing HSP90AA1 expression revealed by real-time PCR. Thus, HSP90AA1 was identified as one of the prime targets of Apigenin in CC, and Apigenin could be effective against CC.Communicated by Ramaswamy H. Sarma.

Exploration of the Pharmacological Mechanism of Vitexicarpin against Triple-Negative Breast Cancer in Network Pharmacology

BACKGROUND

Vitexicarpin (VIT), an isoflavone derived from various medicinal herbs, has shown promising anti-tumor activities against multiple cancer cells. However, the understanding of the mechanisms and potential targets of VIT in treating triple-negative breast cancer (TNBC) remains limited.

METHODS

The potential VIT targets were searched for in the Super-PRED online database, while the TNBC targets were acquired in the DisGeNET database, and the Veeny database was used to identify the VIT and TNBC targets that overlapped. Then, GO and KEGG enrichment analyses were carried out in the DAVID database. The protein-protein interaction (PPI) network was constructed to acquire the hub targets in the STRING database, and the overall survival analysis of the hub targets was examined in the Kaplan-Meier plotter database. Afterward, molecular docking was performed to evaluate the binding capabilities between VIT and the hub targets. In order to measure the effect of VIT on proliferation, apoptosis, and cell cycle arrest in the TNBC cell lines-MDA-MB-231 and HCC-1937-the Cell Counting Kit-8 (CCK-8) assay and flow cytometry analysis were performed. The Western blot and pull-down assays were used to verify the molecular mechanisms by modulating the hub targets.

RESULTS

The network pharmacology results identified a total of 37 overlapping genes that were shared by VIT and TNBC. The results of the PPI network and molecular docking analyses showed that HSP90AA1, CREBBP, and HIF-1A were key targets of VIT against TNBC. However, the pull-down results suggested that VIT could directly bind to HSP90AA1 and HIF-1A, yet not to CREBBP. The results of the in vitro tests showed that VIT decreased proliferation and induced apoptosis in MDA-MB-231 and HCC-1937 cells, in a dose-dependent manner, while the cell cycle arrest occurred at the G2 phase. Mechanistically, the Western blot assay demonstrated that VIT decreased the expression of HSP90AA1, CREBBP, and HIF-1A.

CONCLUSIONS

VIT inhibited growth and induced apoptosis of TNBC cells by modulating HIF-1A, HSP90AA1, and CREBBP expression. Our findings suggest that VIT is a potential drug for TNBC therapy.

Bioinformatics-based identification and validation of hub genes associated with aging in patients with coronary artery disease

Coronary artery disease (CAD) is the most common aging-related disease in adults. We used bioinformatics analysis to study genes associated with aging in patients with CAD. The microarray data of the GSE12288 dataset were downloaded from the Gene Expression Omnibus database to obtain 934 CAD-associated differentially expressed genes. By overlaying them with aging-related genes in the Aging Atlas database, 33 differentially expressed aging-related genes (DEARGs) were identified. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that the 33 DEARGs were mainly enriched in cell adhesion and activation, Th17 and Th1/Th2 cell differentiation, and longevity regulation pathways. Hub genes were further screened using multiple algorithms of Cytoscape software and validation set GSE71226. Clinical samples were then collected, and the expression of hub genes in whole blood was detected by real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and western blot at the transcription and translation levels. Finally, HSP90AA1 and CEBPA were identified as hub genes. The results of this study suggest that HSP90AA1 and CEBPA are closely related to CAD. These findings provide a theoretical basis for the association between aging effectors and CAD, and indicate that these genes may be promising biomarkers for the diagnosis and treatment of CAD.

MiR-424-5p targets HSP90AA1 to facilitate proliferation and restrain differentiation in skeletal muscle development

MiR-424-5p was found to be a potential regulator in the proliferation, migration, and invasion of various cancer cells. However, the effects and functional mechanism of miR-424-5p in the process of myogenesis are still unclear. Previously, using microRNA (miRNA) sequencing and expression analysis, we discovered that miR-424-5p was expressed differentially in the different skeletal muscle growth periods of Xuhuai goats. We hypothesized that miR-424-5p might play an important role in skeletal muscle myogenesis. Then, we found that the proliferation ability of the mouse myoblast cell (C2C12 myoblast cell line) was significantly augmented, whereas the C2C12 differentiation was repressed after increasing the expression of miR-424-5p. Mechanistically, HSP90AA1 presented a close interrelation with miR-424-5p, which was predicted as a target gene in the progression of skeletal muscle myogenesis, using transcriptome sequencing, dual luciferase reporter gene detection, and qRT-PCR. The silencing of HSP90AA1 obviously increased C2C12 proliferation and diminished differentiation, which is consistent with the ability of miR-424-5p in C2C12. Altogether, our findings indicated the role of miR-424-5p as a novel potential regulator via HSP90AA1 during muscle myogenesis progression.

Identification of molecular subtypes and prognostic model to reveal immune infiltration and predict prognosis based on immunogenic cell death-related genes in lung adenocarcinoma

Immunogenic cell death (ICD) has been increasingly indicated to be related to caners. However, ICD's role in Lung adenocarcinoma (LUAD) is still not well investigated. Clinical data along with associated mRNA expression profiles from LUAD cases were collected in TCGA and GEO databases. 13 ICD-related genes were identified. Relations of ICD-related genes expression with prognosis of patients, tumor immune microenvironment (TIME) was analyzed. Then, candidate genes were identified and the prognostic signature were constructed. Afterwards, one nomogram incorporating those chosen clinical data together with risk scores were built. Finally, the effect of HSP90AA1, one gene of the prognostic signature, on LUAD cell were analyzed. Two clusters were identified, which were designated as the ICD-high or -low subtype according to ICD-related genes levels. ICD-high subgroup showed good prognosis, high immune cell infiltration degrees, and enhanced immune response signaling activity compared with ICD-low subtype. Moreover, we established and verified the risk signature based on ICD-related genes. High risk group predicted poor prognosis of LUAD independently and presented negative association with immune score and immune status. Furthermore, nomogram contributed to the accurate prediction of LUAD prognostic outcome. Finally, HSP90AA1 levels were remarkably elevated within tumor cells in comparison with healthy pulmonary epithelial cells. HSP90α, HSP90AA1 protein product, promoted growth, migration, and invasion of LUAD cells. Molecular subtypes and prognostic model were identified by incorporating ICD-related genes, and it was related to TIME and might be adopted for the accurate prediction of LUAD prognosis.

Identifying luteolin as a potential drug for treating lung adenocarcinoma with COVID-19 affection based on integration analysis of pharmacology and transcriptome

BACKGROUND

Lung adenocarcinoma (LUAD) is a major type of lung cancer worldwide, and under the pandemic coronavirus disease 2019 (COVID-19), its cancer burden is enlarged. This study aimed to explore potential drug targets and potential drugs for developing effective treatments for patients with both lung cancer and COVID-19.

METHOD

The interaction network of molecule compounds-target genes was constructed based on Traditional Chinese Medicines (TCMs) and gene expression data from public databases. The potential effectiveness of drugs was analyzed by molecular docking and molecular dynamics simulation. Western blot, transfection assay, Immunohistochemistry (IHC) staining, and flow cytometry were performed to investigate the function of HSP90AA1 in LUAD cells.

RESULT

Eight target genes (GSK3B, HMOX1, HSP90AA1, ICAM1, MAPK1, PLAU, RELA and TNFSF15.) were identified, and two of them (HSP90AA1 and RELA) were significantly associated with LUAD prognosis. Luteolin was discovered to bind with HSP90AA1. Moreover, In vitro cell experiments demonstrated that HSP90AA1 had higher expression in A549 cells, promoted cell viability and suppressed apoptosis in A549 cells and H1299 cells.

CONCLUSION

HSP90AA1 was a target gene for further designing effective drugs for LUAD patients. Luteolin was a potential drug for treating patients with both LUAD and COVID-19.

HSP90AA1 promotes lymphatic metastasis of hypopharyngeal squamous cell carcinoma by regulating epithelial-mesenchymal transition

Background

Lymphatic metastasis (LM) emerges as an independent prognostic marker for hypopharyngeal squamous cell carcinoma (HSPSCC), chiefly contributing to treatment inefficacy. This study aimed to scrutinize the prognostic relevance of HSP90AA1 and its potential regulatory mechanism of concerning LM in HPSCC.

Methods

In a preceding investigation, HSP90AA1, a differential gene, was discovered through transcriptome sequencing of HPSCC tissues, considering both the presence and absence of LM. Validation of HSP90AA1 expression was accomplished via qRT-PCR, western-blotting(WB), and immunohistochemistry(IHC), while its prognostic significance was assessed employing Kaplan-Meier survival analysis(KMSA), log-rank test(LR), and Cox's regression analysis(CRA). Bioinformatics techniques facilitated the prediction and analysis of its plausible mechanisms in LM, further substantiated by in vitro and in vivo experiments utilizing FaDu cell lines.

Results

HSP90AA1 is substantially up-regulated in HPSCC with LM and is identified as an independent prognostic risk determinant. The down-regulation of HSP90AA1 can achieve inhibition of tumor cell proliferation, migration and invasion. Both in vivo experiments and Bioinformatics exploration hint at promoting LM by Epithelial-mesenchymal transition (EMT), regulated by HSP90AA1.

Conclusions

HSP90AA1, by controlling EMT, can foster LM in HPSCC.This finding sets the foundation for delving into new therapeutic targets for HPSCC.

Ergothioneine attenuates varicocele-induced testicular damage by upregulating HSP90AA1 in rats

This study investigates the therapeutic effect and the underlying mechanisms of ergothioneine (EGT) on the testicular damage caused by varicocele (VC) in vivo, in vitro, and in silico. This preclinical study combines a series of biological experiments and network pharmacology analyses. A total of 18 Sprague Dawley (SD) male rats were randomly and averagely divided into three groups: the sham-operated, VC model, and VC model with EGT treatment (VC + EGT) groups. The left renal vein of the VC model and the VC + EGT groups were half-ligated for 4 weeks. Meanwhile, the VC + EGT group was intragastrically administrated with EGT (10 mg/kg). GC1 and GC2 cells were exposed to H₂ O₂ with or without EGT treatment to re-verify the conclusion. The structure disorder of seminiferous tubules ameliorated the apoptosis decrease in the VC rats receiving EGT. EGT can also increase the sperm quality of the VC model rats (p < 0.05). The exposure to H₂ O₂ decreased proliferation and increased apoptosis of GC1 and GC2 cells, which was revisable by adding EGT to the plates (p < 0.05). The network pharmacology and molecular docking were conducted to explore the potential targets of EGT in VC, and HSP90AA1 was identified as the pivotal gene, which was validated by western blot, immunohistochemistry, and RT-qPCR both in vivo and in vitro (p < 0.05). Overall, EGT attenuates the testicular injury in the VC model both in vivo and in vitro by potentially potentiating the expression of HSP90AA1.

HSP90AA1 interacts with CSFV NS5A protein and regulates CSFV replication via the JAK/STAT and NF-κB signaling pathway

Classical swine fever (CSF), caused by the classical swine fever virus (CSFV), is a highly contagious and fatal viral disease, posing a significant threat to the swine industry. Heat shock protein 90 kDa alpha class A member 1 (HSP90AA1) is a very conservative chaperone protein that plays an important role in signal transduction and viral proliferation. However, the role of HSP90AA1 in CSFV infection is unknown. In this study, we found that expression of HSP90AA1 could be promoted in PK-15 and 3D4/2 cells infected by CSFV. Over-expression of HSP90AA1 could inhibit CSFV replication and functional silencing of HSP90AA1 gene promotes CSFV replication. Further exploration revealed that HSP90AA1 interacted with CSFV NS5A protein and reduced the protein levels of NS5A. Since NS5A has an important role in CSFV replication and is closely related to type I IFN and NF-κB response, we further analyzed whether HSP90AA1 affects CSFV replication by regulating type I IFN and NF-κB pathway responses. Our research found HSP90AA1 positively regulated type I IFN response by promoting STAT1 phosphorylation and nuclear translocation processes and promoted the nuclear translocation processes of p-P65. However, CSFV infection antagonizes the activation of HSP90AA1 on JAK/STAT and NF-κB pathway. In conclusion, our study found that HSP90AA1 overexpression significantly inhibited CSFV replication and may inhibit CSFV replication by interacting with NS5A and activating JAK/STAT and NF-κB signaling pathways. These results provide new insights into the mechanism of action of HSP90AA1 in CSFV infection, which abundant the candidate library of anti-CSFV.

HSP90AA1 promotes the inflammation in human gingival fibroblasts induced by Porphyromonas gingivalis lipopolysaccharide via regulating of autophagy

BACKGROUND

Peri-implantitis of tooth seriously affects the life quality of patients. This study aimed to investigate the role of HSP90AA1 in the inflammatory of human gingival fibroblasts (HGFs) induced by porphyromonas gingivalis lipopolysaccharide (Pg-LPS), and to provide a potential therapeutic target for clinical treatment of peri-implantitis.

METHODS

Pg-LPS (0.1, 1, 10 μg/mL) was used to construct the inflammatory model of HGFs to evaluate the effect of Pg-LPS on HGFs. Then HSP90AA1-siRNA was transfected to construct HSP90AA1 low expression HGFs cell line, and 3-MA was also added. After that, cell viability, apoptosis, the contents of inflammatory cytokines were detected by CCK-8, flow cytometry and ELISA assay, respectively. Intracellular ROS, the expressions of HSP90α, HSP90β were detected by immunofluorescence. The levels of HSP90AA1, p-NF-κB p65/NF-κB p65, LC3 II/I, ATG5, Beclin-1 and TLR protein were detected by western blot.

RESULTS

Pg-LPS treatment didn't affect the viability of HGFs cells, but induced the cell apoptosis and ROS generation, increased the contents of IL-1β, IL-6, TNF-α, and the protein expressions of HSP90AA1, p-NF-κBp65/NF-κBp65, LC3II/I, ATG5, and Beclin-1 in HGFs. While HSP90AA1-siRNA transfected into Pg-LPS induced HGFs significantly reduced the HSP90AA1, HSP90α, HSP90β expression, decreased the inflammatory factors, ROS generation, cell apoptosis rate, and autophagy-related proteins and TLR2/4 protein levels. What's more, the addition of autophagy inhibitor 3-MA further promote the effect of HSP90AA1-siRNA on Pg-LPS treated HGFs.

CONCLUSIONS

This study showed that HSP90AA1 promoted the inflammatory response of Pg-LPS induced HGFs by regulating autophagy. The addition of 3-MA further confirmed that autophagy may mediate siHSP90AA1 to enhance the inflammatory response.

DAB2IP down-regulates HSP90AA1 to inhibit the malignant biological behaviors of colorectal cancer

Background

Studies have shown that DAB2IP inhibits cancer progression, while HSP90AA1 promotes cancer progression. However, the specific regulatory mechanism of DAB2IP and HSP90AA1 in colorectal cancer (CRC) is not clear. Our aim is to investigate the role and mechanism of DAB2IP and HSP90AA1 in the development of CRC.

Methods

We used bioinformation to analyze the interaction between DAB2IP and HSP90AA1 and predict their downstream pathways. Then, a series of in vitro and in vivo experiments were conducted to reveal the role of DAB2IP and HSP90AA1 in the invasion and metastasis of colorectal cancer, and flow cytometry was used to explore their effects on apoptosis.

Results

Loss of DAB2IP was associated with poor prognosis of CRC. In contrast, elevated expression of HSP90AA1 was associated with the malignant behavior of CRC. The present study demonstrated a negative correlation between DAB2IP and HSP90AA1. Using bioinformatic analysis, we scanned SRP9 which was highly expressed in CRC, as a co-related gene of DAB2IP and HSP90AA1. Mechanistically, DAB2IP promoted apoptosis through HSP90AA1/SRP9/ASK1/JNK signaling axis in CRC.

Conclusions

These findings provide evidence that DAB2IP-based therapy may enhance the anticancer effect of HSP90AA1 inhibitors, and combined targeting of DAB2IP and HSP90AA1 may be a powerful treatment strategy to combat CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09596-z.

Uncovering the molecular mechanisms of Ilex pubescens against myocardial ischemia-reperfusion injury using network pharmacology analysis and experimental pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Ilex pubescens (I. pubescens), has been widely used to treat cardiovascular disease (CVD) in South China. Several studies have revealed aspect of its phytochemistry and pharmacological activities in cardiovascular diseases, but its active compounds and mechanisms of action are still unclear. The aim of this study was to search for the active compounds and the pharmacological mechanisms of I. pubescens for myocardial ischemia-reperfusion injury (MI/RI) by an integrative pharmacology-based investigation.

MATERIALS AND METHODS

The main targets of compounds in I. pubescens were predicted using the TargetNet webserver (http://targetnet.scbdd.com). The network between compounds and predicted targets related to MI/RI and compounds was constructed. Functional enrichment analysis was performed to investigate the specific functions and pathways involved in the candidate I. pubescens targets acting on MI/RI, which were further validated by in vitro and in vivo experiments.

RESULTS

A total of 191 targets were predicted for 64 chemical compounds in I. pubescens. Following Venn's analysis, we found that 38 candidate targets of I. pubescens were associated with protective effects against MI/RI. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that these targets were related to estrogen signaling pathway. Importantly, the cardioprotective effects of I. pubescens and its active compounds were evaluated and the regulatory effects on key targets of heat shock protein 90 alpha family class A member 1 (HSP90AA1) and Estrogen receptor 1 (ESRα) in estrogen signaling pathway were validated in vitro and in vivo.

CONCLUSION

Our discoveries revealed that I. pubescens ameliorated MI/RI by regulating HSP90AA1 and ESRα in estrogen signaling pathway.

Knockdown of lncRNA ZNRD1-AS1 suppresses gastric cancer cell proliferation and metastasis by targeting the miR-9-5p/HSP90AA1 axis

LncRNAs play an important role in a variety of biological processes, such as cancer pathogenesis. The lncRNA zinc ribbon domain containing 1 antisense RNA 1 (ZNRD1-AS1) is a natural antisense transcript of ZNRD1. In this study, we found that ZNRD1-AS1 levels were significantly upregulated in gastric cancer tissues compared to those in adjacent healthy gastric tissues. ZNRD1-AS1 levels were correlated with lymph node metastasis, distal metastasis, and TNM stage, but were not correlated with age and sex. ZNRD1-AS1 knockdown suppressed cell proliferation, migration, and invasion, and promoted apoptosis. ZNRD1-AS1 overexpression had the opposite effect. ZNRD1-AS1 knockdown suppressed tumor growth and pulmonary metastasis in a nude mouse model ZNRD1-AS1 can bind to miR-9-5p and ZNRD1-AS1 knockdown can decrease the protein level of heat shock protein 90 alpha family class A member 1 (HSP90AA1), which is the target of miR-9-5p. The miR-9-5p inhibitor rescued the effect of ZNRD1-AS1 knockdown, and the mutant of miR-9-5p binding site on ZNRD1-AS1 sequence blocked the effect of ZNRD1-AS1 overexpression. In conclusion, ZNRD1-AS1 levels were upregulated in gastric cancer tissues, and knockdown of ZNRD1-AS1 suppressed gastric cancer cell proliferation and metastasis by targeting the miR-9-5p/HSP90AA1 axis. Our findings provide novel insights into the mechanism underlying the role of ZNRD1-AS1 in gastric cancer.

Human heat shock cognate protein (HSC70/HSPA8) interacts with negatively charged phospholipids by a different mechanism than other HSP70s and brings HSP90 into membranes

Heat shock proteins (HSP) are critical elements for the preservation of cellular homeostasis by participating in an array of biological processes. In addition, HSP play an important role in cellular protection from various environmental stresses. HSP are part of a large family of different molecular mass polypeptides, displaying various expression patterns, subcellular localizations, and diversity functions. An unexpected observation was the detection of HSP on the cell surface. Subsequent studies have demonstrated that HSP have the ability to interact and penetrate lipid bilayers by a process initiated by the recognition of phospholipid heads, followed by conformational changes, membrane insertion, and oligomerization. In the present study, we described the interaction of HSPA8 (HSC70), the constitutive cytosolic member of the HSP70 family, with lipid membranes. HSPA8 showed high selectivity for negatively charged phospholipids, such as phosphatidylserine and cardiolipin, and low affinity for phosphatidylcholine. Membrane insertion was mediated by a spontaneous process driven by increases in entropy and diminished by the presence of ADP or ATP. Finally, HSPA8 was capable of driving into the lipid bilayer HSP90 that does not display any lipid biding capacity by itself. This observation suggests that HSPA8 may act as a membrane chaperone.

Identification of sulforaphane regulatory network in hepatocytes by microarray data analysis based on GEO database

For the past several years, more and more attention has been paid to the exploration of traditional medicinal plants. Further studies have shown that more dietary consumption of cruciferous vegetables can prevent the occurrence of tumor, indicating the potential applications in the chemoprevention of cancer. Sulforaphane (SFN) has been identified by the National Cancer Institute as a candidate for chemopreventive research; it is one of several compounds selected by the National Cancer Institute’s Rapid Access to Preventive Intervention Development Program and is currently in use. In the present study, based on the data of Gene Expression Omnibus database (GEO), the gene expression profile of hepatocytes that were treated with SFN was analyzed. The ANOVA and Limma packets in R were used to analyze the differentially expressed genes (DEGs). On this basis, gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway enrichment were further analyzed. The core gene HSP90-α (cytosolic), class A member 1 (HSP90AA1) was screened by protein–protein interaction (PPI) network established by STRING and Cytoscape software for further study. Finally, miRNAs targeted HSP90AA1 were predicted by miRanda. All in all, based on the data of GSE20479 chip, the molecular mechanism of SFN on hepatocytes was studied by a series of bioinformatics analysis methods, and it indicated that SFN might effect on the hepatocyte by regulating HSP90AA1.

[Effect and mechanism of total flavonoids of Lichi Semen on CCl_4-induced liver fibrosis in rats, and prediction of Q-marker]

This paper was to investigate the effect of total flavonoids of Lichi Semen(TFL) on carbon tetrachloride(CCl_4)-induced liver fibrosis in rats, analyze and predict its mechanism of action and potential quality markers(Q-marker). Firstly, male SD rats were taken and injected subcutaneously with a 40% CCl_4-vegetable oil solution twice a week for 8 consecutive weeks to establish a rat model of liver fibrosis. The rats with liver fibrosis were randomly divided into model group, silybin group(43.19 mg·kg~(-1)), Fuzheng Huayu Capsules group(462.75 mg·kg~(-1)), and TFL groups(100 mg·kg~(-1) and 25 mg·kg~(-1)), with normal rats as a blank group, 10 rats in each group. Except for the blank group, the rats in the other groups were subcutaneously injected with 40% CCl_4-vegetable oil solution of a maintenance dose, once a week. The rats in various treatment groups received corresponding doses of drugs, while the rats in the blank group and model group received the same volume of normal saline once a day for 4 weeks. At the end of the experiment, blood was collected from the abdominal aorta and the liver tissues were collected. The levels of total bilirubin(TBiL), direct bilirubin(DBiL), indirect bilirubin(IBiL), alanine aminotransferase(ALT), and aspartate aminotransferase(AST) in serum were detected by using an automatic biochemical detector. Masson staining was used to observe the histopathological changes of rat liver. Then, the chemical compositions of TFL were collected, and the action targets of these chemical compositions were predicted through SWISS database and reverse molecular docking server(DRAR-CPI). After screening of disease targets of liver fibrosis by Gene Cards database, the protein-protein interaction was analyzed with use of STRING database, and GO(gene ontology) analysis and KEGG(Kyoto encyclopedia of genes and genomes) enrich analysis were also carried out. Moreover, an iTRAQ proteomics technology was used to determine protein expression in liver tissues of rats in TFL, model and blank groups to verify the targets. Furthermore, Cytoscape software was used to establish and visualize the network of chemical components, targets and pathways, and predict the potential Q-marker of TFL. The results showed that the levels of TBiL, DBiL, IBiL, ALT, and AST in the model group were significantly higher than those in the blank normal group(P&lt;0.05), and the above levels in the treatment groups were lower than those in the model group, but with no significant differences. Masson staining showed that the liver damage and the degree of fibrosis were severe in the model group, and were relieved to different degrees in the treatment groups. Then, 74 chemical components were screened, which could act on 865 targets such as EGFR and SRC, participating in the regulation of cancer pathways, PI3 K-Akt signaling pathway, HIF-1 signaling pathway and other signaling pathways closely related to liver fibrosis. Pinocembrin, quercetin, epicatechin, procyanidin A2, naringenin, nobiletin, phlorizin and rutin showed the highest correlation with liver fibrosis-related targets and pathways. Proteomics results showed that a total of 18 proteins among the 45 proteins predicted by internet pharmacology were identified, among which 6 proteins were significantly expressed, including 5 up-regulated proteins and 1 down-regulated protein. The protein expression of ALB, PLG, HSP90 AA1, EGFR and MAP2 K1 was significantly returned to a normal state in the TFL treatment groups. In conclusion, TFL may demonstrate the anti-hepatic fibrosis and potential hepatoprotective effects by regulating the expression of ALB, PLG, HSP90 AA1, EGFR and MAP2 K1, which may be associated with the regulation of multiple signaling pathways related to liver fibrosis such as PI3 K-Akt pathway. Pinocembrin, quercetin, epicatechin, procyanidin A2, naringenin, nobiletin, phlorizin and rutin could be regarded as potential Q-markers of TFL for quality control.

Molecular convergent and parallel evolution among four high-elevation anuran species from the Tibetan region

BACKGROUND

To date, evidence for the relative prevalence or rarity of molecular convergent and parallel evolution is conflicting, and understanding of how these processes contribute to adaptation is limited. We compared four high-elevation anuran species (Bufo tibetanus, Nanorana parkeri, Rana kukunoris and Scutiger boulengeri) from the Tibetan region, and examined convergent and parallel amino acid substitutions between them and how they may have contributed to high-elevation adaptation.

RESULTS

Genomic data of the four high-elevation species and eight of their low-elevation close relatives were gathered. A total of 1098 orthologs shared by all species were identified. We first conducted pairwise comparisons using Zhang and Kumar's test. Then, the R_conv index was calculated and convergence/divergence correlation plotting was conducted. Furthermore, genes under positive selection and with elevated evolutionary rate were examined. We detected a large number of amino acid sites with convergent or parallel substitutions. Several pairs of high-elevation species, in particular, R. kukunoris vs N. parkeri and B. tibetanus vs S. boulengeri, had excessive amounts of convergent substitutions compared to neutral expectation. Nevertheless, these sites were mostly concentrated in a small number of genes (3-32), and no genome-wide convergence was detected. Furthermore, the majority of these convergent genes were neither under detectable positive selection nor had elevated evolutionary rates, although functional prediction analysis suggested some of the convergent genes could potentially contribute to high-elevation adaptation.

CONCLUSIONS

There is a substantial amount of convergent evolution at the amino-acid level among high-elevation amphibians, although these sites are concentrated in a few genes, not widespread across the genomes. This may attribute to the fact that all the target species are from the same environment. The relative prevalence of convergent substitutions among high-elevation amphibians provides an excellent opportunity for further study of molecular convergent evolution.

Influenza A Virus Induces Autophagy by Its Hemagglutinin Binding to Cell Surface Heat Shock Protein 90AA1

Autophagy can be utilized by the influenza A virus (IAV) to facilitate its replication. However, whether autophagy is induced at the stage of IAV entry is still unclear. Here, we report that IAV induces autophagy by hemagglutinin (HA) binding to heat shock protein 90AA1 (HSP90AA1) distributed on the cell surface. Virus overlay protein binding assay and pull-down assay indicated that IAV HA bound directly to cell surface HSP90AA1. Knockdown of HSP90AA1 weakened H1N1 infection. Incubation of IAV viral particles with recombinant HSP90AA1 or prior blockade of A549 cells with an anti-HSP90AA1 antibody could inhibit attachment of IAV. Moreover, we found that recombinant HA1 protein binding to cell surface HSP90AA1 was sufficient to induce autophagy through the AKT-MTOR pathway. Our study reveals that the HSP90AA1 on cell surface participates in IAV entry by directing binding to the HA1 subunit of IAV and subsequently induces autophagy.

Secretory autophagy machinery and vesicular trafficking are involved in HMGB1 secretion

Nuclear protein HMGB1 is secreted in response to various stimuli and functions as a danger-associated molecular pattern. Extracellular HMGB1 induces inflammation, cytokine production, and immune cell recruitment via activation of various receptors. As HMGB1 does not contain an endoplasmic reticulum-targeting signal peptide, HMGB1 is secreted via the endoplasmic reticulum-Golgi independently via an unconventional secretion pathway. However, the mechanism underlying HMGB1 secretion remains largely unknown. Here, we investigated the role of secretory autophagy machinery and vesicular trafficking in HMGB1 secretion. We observed that HSP90AA1 (heat shock protein 90 alpha family class A member 1), a stress-inducible protein, regulates the translocation of HMGB1 from the nucleus to the cytoplasm and its secretion through direct interaction. Additionally, geldanamycin, an HSP90AA1 inhibitor, reduced HMGB1 secretion. GORASP2/GRASP55 (golgi reassembly stacking protein 2), ARF1^Q71L (ADP ribosylation factor 1), and SAR1A^T39N (secretion associated Ras related GTPase 1A), which promoted unconventional protein secretion, increased HMGB1 secretion. HMGB1 secretion was inhibited by an early autophagy inhibitor and diminished in ATG5-deficient cells even when GORASP2 was overexpressed. In contrast, a late autophagy inhibitor increased HMGB1 secretion under the same conditions. The multivesicular body formation inhibitor GW4869 dramatically decreased HMGB1 secretion under HMGB1 secretion-inducing conditions. Thus, we demonstrated that secretory autophagy and multivesicular body formation mediate HMGB1 secretion.

FBXL6 governs c-MYC to promote hepatocellular carcinoma through ubiquitination and stabilization of HSP90AA1

Background

Heat shot protein 90 (HSP90) AA1 functions as an onco-protein to regulate the assembly, manipulation, folding and degradation of its client proteins, including c-MYC. However, little is known about the mechanism of HSP90AA1 regulation.

Methods

Transcriptome RNA-sequencing data of hepatocellular carcinoma (HCC) samples were used to detect the mRNA expression of FBXL6. Immunoprecipitation/Mass Spectrum (IP/MS) method was used to identify the interacting proteins of FBXL6. The co-immunoprecipitation assay was used to determine the interaction between FBXL6 and HSP90AA1. The in vivo ubiquitination assay was performed to determine the regulation of HSP90AA1 by FBXL6. Luciferase reporter and chromatin immunoprecipitation (ChIP) assays were used to determine the transcriptional regulation of FBXL6 by c-MYC. Immunohistochemical (IHC) staining was performed to study the correlation of FBXL6 and HSP90AA1 protein expression in 87 HCC samples. Cell counting and colony formation assays were implemented to detect the biological effects of FBXL6 on the growth of HCC cells in vitro. The effect of FBXL6 on HCC tumor growth in vivo was studied in a tumor xenograft model in mice.

Results

Here, we identified the orphan F-box protein FBXL6, a substrate recognition subunit of an SCF (Skp1-Cul1-F-box protein) complex, as the ubiquitin ligase for HSP90AA1. FBXL6 promoted K63-dependent ubiquitination of HSP90AA1 to stabilize it. Through analysis of the TCGA dataset, we found that FBXL6 was significantly increased in HCC tissues and positively correlated with c-MYC pathway. FBXL6 accumulation in HCC causes the stabilization and activation of c-MYC by preventing HSP90AA1 degradation. The activated c-MYC directly binds to the promoter region of FBXL6 to induce its mRNA expression.

Conclusion

Collectively, our data revealed an unknown FBXL6-HSP90AA1-c-MYC axis which might contribute to the oncogenesis of HCC, and we propose that inhibition of FBXL6 might represent an effective therapeutic strategy for HCC treatment.

MicroRNA-361-Mediated Inhibition of HSP90 Expression and EMT in Cervical Cancer Is Counteracted by Oncogenic lncRNA NEAT1

Epithelial-mesenchymal transition (EMT) is a key process contributing to cervical cancer (CC) metastasis, and microRNAs (miRNAs) modulate the expression of genes implicated in EMT. However, the accurate role of miR-361 in CC-associated EMT and the mechanisms underlying its function in CC remains largely unknown. The functional roles of miR-361 in CC cells were explored by a series of cell functional assays. Luciferase reporter assays were used to demonstrate the potential interaction between miR-361, HSP90, and long non-coding RNA (lncRNA) NEAT1. We detected a reduction of miR-361 expression in CC tissues compared with normal tissues, and miR-361 overexpression inhibited invasion and EMT phenotypes of CC cells by directly targeting a key EMT activator HSP90. Additionally, we detected significantly higher levels of HSP90 in CC tissues compared with normal tissues, and high expression of HSP90 predicted a poorer prognosis. We further identified NEAT1 as a significantly upregulated lncRNA in CC tissues and high expression of NEAT1 was associated with worse survival in CC patients. NEAT1 directly repressed miR-361 expression and played an oncogenic role in CC cell invasion and sphere formation. Conclusions: These results demonstrated that miR-361 directly targets HSP90 to inhibit the invasion and EMT features, and NEAT1 functions as an oncogenic lncRNA that suppresses miR-361 expression and induces EMT and sphere formation in CC cells, thus providing critical insights into the molecular pathways operating in this malignancy.

Genetic polymorphisms in part of intron 7 and exon 8 of HSP90AA1 gene and its association with heat tolerance traits in two exotic layer chicken strains

Chickens, like other vertebrates, react to stress conditions through their cultured cells by expressing heat shock proteins (HSPs). Genetic association of single-nucleotide polymorphisms (SNPs) in HSPs with desirable traits will reveal their importance as potential genetic markers. Blood samples were collected from 50 birds per strain for DNA extraction, polymerase chain reaction amplification and sequencing of the HSP90AA1 gene. SNPs were detected using Codoncode Aligner. Association of each SNP with heat tolerance traits was analysed using generalized linear model procedure of SAS. A total of seven SNPs were detected, four SNPs; A7T, A160T, T223A and C134T were detected in part of intron 7 to exon 8 of HSP90AA1 gene of BRD while three A160T, T223A and C134T were detected in HYL. SNPC134T, a synonymous variant, was detected in exon 8. Only SNPA7T was in Hardy-Weinberg equilibrium (X² = 0.03) but had no association with the traits measured. Polymorphic information content calculated showed SNPA160T to be moderately polymorphic; other SNPs were lowly polymorphic. Heterozygosity for SNPs-A160T and T223A of BRD showed moderate genetic variation while the other SNPs and those in HYL recorded low genetic variation. The study concluded that the SNPs detected were majorly lowly polymorphic and also the SNP locus A7T in intron 7 of HSP90AA1 of BRD had no genetic association with heat tolerance traits.

Extracellular Hsp90α and clusterin synergistically promote breast cancer epithelial-to-mesenchymal transition and metastasis via LRP1

Extracellular heat shock protein 90 alpha (eHsp90α, also known as HSP90AA1) has been widely reported to promote tumor cell motility and tumor metastasis in various types of cancer. Several extracellular proteins and membrane receptors have been identified as interacting proteins of eHsp90α and mediate its pro-metastasis function. However, the regulatory mechanism of eHsp90α activity remains largely unknown. Here, we report that clusterin, a protein newly demonstrated to interact with eHsp90α, modulates eHsp90α signaling. We found that clusterin potentiated the effects of eHsp90α on activation of the AKT, ERK and NF-κB protein families, epithelial-to-mesenchymal transition (EMT) and migration in breast cancer cells. Furthermore, in vivo investigations demonstrated similar synergistic effects of eHsp90α and clusterin on tumor metastasis. Notably, the effects of eHsp90α and clusterin were mediated by low-density lipoprotein receptor-related protein 1 (LRP1). Proximity ligation assay and co-immunoprecipitation experiments demonstrated that clusterin participated in eHsp90α-LRP1 complex formation, which enhanced the binding affinity of eHsp90α to LRP1. Collectively, our data establish a role of clusterin as a newly discovered modulator of eHsp90α, and unravel detailed molecular mechanisms underlying the synergistic metastasis-promoting effects of clusterin and eHsp90α.

Autophagy Promotes Replication of Influenza A Virus In Vitro

Influenza A virus (IAV) infection could induce autophagosome accumulation. However, the impact of the autophagy machinery on IAV infection remains controversial. Here, we showed that induction of cellular autophagy by starvation or rapamycin treatment increases progeny virus production, while disruption of autophagy using a small interfering RNA (siRNA) and pharmacological inhibitor reduces progeny virus production. Further studies revealed that alteration of autophagy significantly affects the early stages of the virus life cycle or viral RNA synthesis. Importantly, we demonstrated that overexpression of both the IAV M2 and NP proteins alone leads to the lipidation of LC3 to LC3-II and a redistribution of LC3 from the cytosol to punctate vesicles indicative of authentic autophagosomes. Intriguingly, both M2 and NP colocalize and interact with LC3 puncta during M2 or NP transfection alone and IAV infection, leading to an increase in viral ribonucleoprotein (vRNP) export and infectious viral particle formation, which indicates that the IAV-host autophagy interaction plays a critical role in regulating IAV replication. We showed that NP and M2 induce the AKT-mTOR-dependent autophagy pathway and an increase in HSP90AA1 expression. Finally, our studies provided evidence that IAV replication needs an autophagy pathway to enhance viral RNA synthesis via the interaction of PB2 and HSP90AA1 by modulating HSP90AA1 expression and the AKT-mTOR signaling pathway in host cells. Collectively, our studies uncover a new mechanism that NP- and M2-mediated autophagy functions in different stages of virus replication in the pathogenicity of influenza A virus.IMPORTANCE Autophagy impacts the replication cycle of many viruses. However, the role of the autophagy machinery in IAV replication remains unclear. Therefore, we explored the detailed mechanisms utilized by IAV to promote its replication. We demonstrated that IAV NP- and M2-mediated autophagy promotes IAV replication by regulating the AKT-mTOR signaling pathway and HSP90AA1 expression. The interaction of PB2 and HSP90AA1 results in the increase of viral RNA synthesis first; subsequently the binding of NP to LC3 favors vRNP export, and later the interaction of M2 and LC3 leads to an increase in the production of infectious viral particles, thus accelerating viral progeny production. These findings improve our understanding of IAV pathogenicity in host cells.

Overexpression of heat shock protein HSP90AA1 and translocase of the outer mitochondrial membrane TOM34 in HCV-induced hepatocellular carcinoma: A pilot study

OBJECTIVE

Identification of new molecular markers to enhance early diagnosis, prognosis and/or treatment of hepatocellular carcinoma (HCC) is a need. TOM34 (34 kDa-translocase of the outer mitochondrial membrane) protein expression deregulation has demonstrated to be involved in the growth of many cancers. Here, we aimed at evaluating serum TOM34 and some heat shock proteins (HSPA4, HSPA1B, and HSP90AA1) expressions in hepatitis C virus (HCV)-related cirrhosis and HCV-induced HCC relative to controls and correlating these expressions to the clinicopathological data.

METHODS

Serum specimens were collected from 90 patients with HCV associated complications (30 cirrhotic, 30 early HCC and 30 late HCC) and 60 controls. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed for relative quantification of the four target genes using the Livak method. In silico network analysis was also executed to explore the contribution of the genes in liver cancer.

RESULTS

The serum TOM34 and HSP90AA1 transcripts were significantly upregulated in HCC patients compared to cirrhotic ones with more up-regulation in late HCC patients. Receiver operating characteristic analysis showed the optimum cutoff value of 0.625 corresponding to 71.7% sensitivity and 56.7% specificity, and an area under the curve (AUC) of 0.705 to discriminate HCC from cirrhotic groups (P = .002). In multivariate analysis, ordination plot showed obvious demarcation between the study groups caused by the higher levels of TOM34 among other variables.

CONCLUSIONS

TOM34 and its partner HSP90AA1 might be used as a potential biomarker for monitoring HCV-induced HCC progression in the Egyptian population. Future large-scale validation studies are warranted.

KCNQ1OT1 facilitates progression of non-small-cell lung carcinoma via modulating miRNA-27b-3p/HSP90AA1 axis

Long noncoding RNA KCNQ1OT1 participates in the regulation of imprinted genes within the kcnq1 domain. But its roles in carcinogenesis and metastasis remain largely elusive. Herein, we evaluated its potential in non-small-cell lung cancer (NSCLC) progression. We demonstrated that the KCNQ1OT1 level was upregulated in NSCLC tissues and cell lines. High KCNQ1OT1 level correlated with poor overall and progression-free survival in NSCLC patients. KCNQ1OT1 facilitated proliferation, migration, and invasion in H460 cells. Furthermore, knockdown of KCNQ1OT1 reduced the expression of HSP90AA1. KCNQ1OT1 presented a positive correlation with HSP90AA1 which predicted the tumor progression in NSCLC from The Cancer Genome Atlas database. Intriguingly, KCNQ1OT1 modulated HSP90AA1 expression by sponging miR-27b-3p. MiR-27b-3p counteracted the effect of KCNQ1OT1 on HSP90AA1 expression, H460 cell migration, and invasion. These data revealed a role for KCNQ1OT1 as an oncogene through miR-27b-3p/HSP90AA1 axis during NSCLC progression.

HSP90AA1-mediated autophagy promotes drug resistance in osteosarcoma

Background

Osteosarcoma is the most common primary bone tumor in children and adolescents. Unfortunately, osteosarcoma treatments often fail due to the development of chemoresistance, of which the underlying molecular mechanisms still remain unclear. In this study, we demonstrated that HSP90AA1 gene is responsible for drug resistance in osteosarcoma through an autophagy-related mechanism.

Methods

shRNAs were transfected into osteosarcoma cells for knockdown of HSP90AA1 gene. Stable HSP90AA1 overexpressing osteosarcoma cell lines were obtained by lentivirus infection. mRNA and protein expressions of HSP90AA1 in osteosarcoma cells were tested by quantitative real-time PCR and western blot, respectively. Autophagy of osteosarcoma cells was detected by western blot of LC3, transmission electron microscopy and fluorescence microscope. mRFP-GFP-LC3 lentiviral transfection was also performed to detect autophagic flux. NOD/SCID mices were inoculated with MG-63 tumor cells transfected with HSP90AA1 specific shRNA. TUNEL and LC3 staining were performed to detect apoptosis and autophagy of resected tumor tissues.

Results

Doxorubicin, cisplatin, and methotrexate, which are commonly used in chemotherapy, each induced HSP90AA1 upregulation in human osteosarcoma cells. Suppression of HSP90AA1 restored the sensitivity of osteosarcoma cells to chemotherapy both in vivo and in vitro. Mechanism study indicated that autophagy is responsible for the chemoresistance in osteosarcoma cells. HSP90AA1 increased drug resistance by inducing autophagy and inhibiting apoptosis. Suppression of HSP90AA1 diminished autophagic protection in response to chemotherapy in osteosarcoma cells. Moreover, HSP90AA1 promotes autophagy through PI3K/Akt/mTOR pathway and inhibits apoptosis through JNK/P38 pathway.

Conclusion

We showed that chemotherapy agents can induce HSP90AA1 expression in osteosarcoma cells. And HSP90AA1, acting as an important regulator of autophagy, is a critical factor in the development of osteosarcoma chemoresistance both in vitro and in vivo. HSP90AA1 provides a novel therapeutic target for improving osteosarcoma treatment.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0880-6) contains supplementary material, which is available to authorized users.

Electrophilic aldehyde products of lipid peroxidation selectively adduct to heat shock protein 90 and arylsulfatase A in stallion spermatozoa

Oxidative stress is a major determinant of mammalian sperm function stimulating lipid peroxidation cascades that culminate in the generation of potentially cytotoxic aldehydes. The aim of this study was to assess the impact of such aldehydes on the functionality of stallion spermatozoa. The impact of exposure to exogenous acrolein (ACR) and 4-hydroxynonenal (4HNE) was manifested in a highly significant dose- and time-dependent increase in mitochondrial reactive oxygen species (ROS), total cellular ROS, a decrease in sperm motility, and a time-dependent increase in lipid peroxidation. Notably, low doses of ACR and 4HNE also caused a significant decrease in zona binding. In contrast, exogenous malondialdehyde, a commonly used marker of oxidative stress, had little impact on the various sperm parameters assessed. In accounting for the negative physiological impact of ACR and 4HNE, it was noted that both aldehydes readily adducted to sperm proteins located predominantly within the head, proximal centriole, and tail. The detoxifying activity of mitochondrial aldehyde dehydrogenase 2 appeared responsible for a lack of adduction in the midpiece; however, this activity was overwhelmed by 24 h of electrophilic aldehyde exposure. Sequencing of the dominant proteins targeted for ACR and 4HNE covalent modification identified heat shock protein 90 alpha (cytosolic) class A member 1 and arylsulfatase A, respectively. These collective findings may prove useful in the identification of diagnostic biomarkers of stallion fertility and resolving the mechanistic basis of sperm dysfunction in this species.

miR-10a and miR-204 as a Potential Prognostic Indicator in Low-Grade Gliomas

This study aimed to identify and characterize microRNAs (miRNAs) that are related to radiosensitivity in low-grade gliomas (LGGs). The miRNA expression levels in radiosensitive and radioresistant LGGs were compared using The Cancer Genome Atlas database, and differentially expressed miRNAs were identified using the EBSeq package. The miRNA target genes were predicted using Web databases. Fifteen miRNAs were differentially expressed between the groups, with miR-10a and miR-204 being related to overall survival (OS) of patients with LGG. Patients with upregulated miR-10a expression had a higher mortality rate and shorter OS time, whereas patients with downregulated miR-204 expression had a lower mortality rate and longer OS time. Two genes, HSP90AA1 and CREB5, were targets for both miRNAs. Thus, this study suggests that expression of miR-10a and miR-204 is significantly related to both radiosensitivity and the survival of patients with LGG. These miRNAs could therefore act as clinical biomarkers for LGG prognosis and diagnosis.

Ratio of proliferation markers and HSP90 gene expression as a predictor of pathological complete response in breast cancer neoadjuvant chemotherapy

INTRODUCTION

Prediction of response to preoperative breast cancer chemotherapy may offer a substantial optimization of medical management of this disease. The most efficient prediction would be done a priori, before the start of chemotherapy and based on the biological features of patient and tumor. Numerous markers have been proposed but none of them has been applied as a routine. The role of MKI67 and HSP90 expression has been recently suggested to predict treatment sensitivity in HER2-positive breast cancer. The aim of this study was to validate the utility of proliferation based markers (MKI67 and CDK1) and heat shock proteins (namely HSP90) to predict response to chemotherapy in cohort of breast cancer patients treated preoperatively.

MATERIAL AND METHODS

Ninety-three patients with breast cancer, all females, mean age 42.2 years, among them 32% T1-T2 patients, 49% T3 patients and 13% with T4 tumor stage, 27% N0, 42% N1, 16% N2, 15% N3 were subjected to initial chemotherapy. The majority of patients (86%) received anthracycline and taxane chemotherapy. Among the patients there were 9 individuals with metastatic disease (M1) at initial presentation, and 11 patients were not treated surgically after initial chemotherapy (no sufficient disease response). From 82 patients operated on, 20 patients (24%) showed pathological complete response (pCR), while in 62 patients there was no pCR. 42% of patients were hormone-sensitive HER2-negative, 20% hormone-sensitive HER2-positive, 9% only HER-positive and 29% with triple negative breast cancer. Four gene transcripts (MKI67, cyclin-dependent kinase 1 [CDK1], heat shock proteins HSP90AA1 and HSP- 90AB1) were analyzed in total RNA isolated from single core obtained during preoperative core needle biopsy by quantitative real-time PCR with fluorescent probes (Universal Probe Library, Roche). Results were normalized to the panel of reference genes.

RESULTS

There were no statistically significant differences in MKI67 and CDK1 expression between pCR and no pCR groups (p = 0.099 and 0.35, respectively), although the median expression of both genes was slightly higher in pCR group. In contrast, both HSP90AA1 and HSP90AB1 transcripts showed decreased expression in pCR group (medians 0.77 and 0.55) when compared to no p CR group (median 0.86 and 0.73), statistically significant for HSP90AA1 (p = 0.031) and of borderline significance for HSP90AB1 (p = 0.054). The most significant predictor of pCR was the ratio of CDK1 transcript to HSP90AA transcript. This ratio was significantly higher in CR group (median 0.99) than in no CR group (median 0.68, p = 0.0023), and showed a potential diagnostic utility (area under receiver operating characteristic [ROC] curve 0.72).

CONCLUSIONS

HSP90AA1 and AB1 genes exhibit low expression in breast cancers highly sensitive to chemotherapy and may indicate the patients with higher probability of pathological complete response. The ratio of HSP90AA1 to proliferation-related markers (CDK1 or MKI67) may be even better predictor of pCR chance, with higher expression of proliferation genes and lower stress response in patients sensitive to chemotherapy.

In silico analysis of regulatory and structural motifs of the ovine HSP90AA1 gene

Gene promoters are essential regions of DNA where the transcriptional molecular machinery to produce RNA molecules is recruited. In this process, DNA epigenetic modifications can acquire a fundamental role in the regulation of gene expression. Recently, in a previous work of our group, functional features and DNA methylation involved in the ovine HSP90AA1 gene expression regulation have been observed. In this work, we report a combination of methylation analysis by bisulfite sequencing in several tissues and at different developmental stages together with in silico bioinformatic analysis of putative regulating factors in order to identify regulative mechanisms both at the promoter and gene body. Our results show a "hybrid structure" (TATA box + CpG island) of the ovine HSP90AA1 gene promoter both in somatic and non-differentiated germ tissues, revealing the ability of the HSP90AA1 gene to be regulated both in an inducible and constitutive fashion. In addition, in silico analysis showed that several putative alternative spliced regulatory motifs, exonic splicing enhancers (ESEs), and G-quadruplex secondary structures were somehow related to the DNA methylation pattern found. The results obtained here could help explain the differences in cell-type transcripts, tissue expression rate, and transcription silencing mechanisms found in this gene.

Binding of the pathogen receptor HSP90AA1 to avibirnavirus VP2 induces autophagy by inactivating the AKT-MTOR pathway

Autophagy is an essential component of host innate and adaptive immunity. Viruses have developed diverse strategies for evading or utilizing autophagy for survival. The response of the autophagy pathways to virus invasion is poorly documented. Here, we report on the induction of autophagy initiated by the pathogen receptor HSP90AA1 (heat shock protein 90 kDa α [cytosolic], class A member 1) via the AKT-MTOR (mechanistic target of rapamycin)-dependent pathway. Transmission electron microscopy and confocal microscopy revealed that intracellular autolysosomes packaged avibirnavirus particles. Autophagy detection showed that early avibirnavirus infection not only increased the amount of light chain 3 (LC3)-II, but also upregulated AKT-MTOR dephosphorylation. HSP90AA1-AKT-MTOR knockdown by RNA interference resulted in inhibition of autophagy during avibirnavirus infection. Virus titer assays further verified that autophagy inhibition, but not induction, enhanced avibirnavirus replication. Subsequently, we found that HSP90AA1 binding to the viral protein VP2 resulted in induction of autophagy and AKT-MTOR pathway inactivation. Collectively, our findings suggest that the cell surface protein HSP90AA1, an avibirnavirus-binding receptor, induces autophagy through the HSP90AA1-AKT-MTOR pathway in early infection. We reveal that upon viral recognition, a direct connection between HSP90AA1 and the AKT-MTOR pathway trigger autophagy, a critical step for controlling infection.

Novel SNP identification in exon 3 of HSP90AA1 gene and their association with heat tolerance traits in Karan Fries (Bos taurus × Bos indicus) cows under tropical climatic condition

Heat shock proteins (HSPs) act as molecular chaperones those are preferentially transcribed in respose to heat stress and the polymorphism in HSP genes associated with heat tolerance traits in cows. HSP90AA1 gene has been mapped on Bos taurus autosome 21 (BTA-21) and spans nearly 5368 bp comprising of 11 exons out of which the first exon does not translate. The present study was done on Karan Fries (5/8 HF × 3/8 Tharparkar) cows reared in tropical climate with the objectives of identifying single-nucleotide polymorphisms (SNPs) in targeted regions (exon 3) of HSP90AA1 gene and analyzing their association with heat tolerance traits in Karan Fries cows. Respiration rate (RR) and rectal temperature (RT) were recorded once daily for four consecutive days during probable extreme hours in different seasons or temperature humidity index (THI), viz., winter, spring, and summer. For detecting single-nucleotide polymorphisms, sequence data were analyzed using BioEdit software (version 7.2). Comparative sequence analysis of HSP90AA1 gene showed point mutation, viz., g.1209A>G (exon 3) as compared to Bos taurus (NCBI Ref Seq: AC_000178.1). Association analysis indicated that THI was influenced (P < 0.01) by RR, RT, and HTC. Similarly, SNPs at locus g.1209A>G were categorized into three genotypes, i.e., AA, AG, and GG, and the least squares means (LSMEANS) of RR, RT, and HTC for GG (homozygous) genotype were significantly lower (P < 0.01) than AA (homozygous) and AG (heterozygous) genotypes. These findings may partly suggest that cows with GG genotypes were favored for heat tolerance trait, which can be used as an aid to selection for thermo-tolerance Karan Fries cows for better adaptation in subtropical and tropical hot climate.

Ovine HSP90AA1 gene promoter: functional study and epigenetic modifications

When environmental temperatures exceed a certain threshold, the upregulation of the ovine HSP90AA1 gene is produced to cope with cellular injuries caused by heat stress. It has been previously pointed out that several polymorphisms located at the promoter region of this gene seem to be the main responsible for the differences in the heat stress response observed among alternative genotypes in terms of gene expression rate. The present study, focused on the functional study of those candidate polymorphisms by electrophoretic mobility shift assay (EMSA) and in vitro luciferase expression assays, has revealed that the observed differences in the transcriptional activity of the HSP90AA1 gene as response to heat stress are caused by the presence of a cytosine insertion (rs397514115) and a C to G transversion (rs397514116) at the promoter region. Next, we discovered the presence of epigenetic marks at the promoter and along the gene body founding an allele-specific methylation of the rs397514116 mutation in DNA extracted from blood samples. This regulatory mechanism interacts synergistically to modulate gene expression depending on environmental circumstances. Taking into account the results obtained, it is suggested that the transcription of the HSP90AA1 ovine gene is regulated by a cooperative action of transcription factors (TFs) whose binding sites are polymorphic and where the influence of epigenetic events should be also taken into account.

Genetic polymorphisms within exon 3 of heat shock protein 90AA1 gene and its association with heat tolerance traits in Sahiwal cows

AIM

The present study was undertaken to identify novel single nucleotide polymorphism (SNP) in Exon 3 of HSP90AA1 gene and to analyze their association with respiration rate (RR) and rectal temperature (RT) in Sahiwal cows.

MATERIALS AND METHODS

The present study was carried out in Sahiwal cows (n=100) with the objectives to identify novel SNP in exon 3 of HSP90AA1 gene and to explore the association with heat tolerance traits. CLUSTAL-W multiple sequence analysis was used to identify novel SNPs in exon 3 of HSP90AA1 gene in Sahiwal cows. Gene and genotype frequencies of different genotypes were estimated by standard procedure POPGENE version 1.32 (University of Alberta, Canada). The significant effect of SNP variants on physiological parameters, e.g. RR and RT were analyzed using the General Linear model procedure of SAS Version 9.2.

RESULTS

The polymerase chain reaction product with the amplicon size of 450 bp was successfully amplified, covering exon 3 region of HSP90AA1 gene in Sahiwal cows. On the basis of comparative sequence analysis of Sahiwal samples (n=100), transitional mutations were detected at locus A1209G as compared to Bos taurus (NCBI GenBank AC_000178.1). After chromatogram analysis, three genotypes AA, AG, and GG with respective frequencies of 0.23, 0.50, and 0.27 ascertained. RR and RT were recorded once during probable extreme hours in winter, spring, and summer seasons. It was revealed that significant difference (p<0.01) among genetic variants of HSP90AA1 gene with heat tolerance trait was found in Sahiwal cattle. The homozygotic animals with AA genotype had lower heat tolerance coefficient (HTC) (1.78±0.04(a)), as compared to both AG and GG genotypes (1.85±0.03(b) and 1.91±0.02(c)), respectively. The gene and genotype frequencies for the locus A1209G were ascertained.

CONCLUSIONS

Novel SNP was found at the A1209G position showed all possible three genotypes (homozygous and heterozygous). Temperature humidity index has a highly significant association with RR, RT, and HTC in all the seasons. Perusal of results across different seasons showed the significant (p<0.01) difference in RR, RT, and HTC among winter, spring, and summer seasons. Genetic association with heat tolerance traits reveals their importance as a potential genetic marker for heat tolerance traits in Sahiwal cows.

Identification of genes related to hepatocellular carcinoma metastasis by a combined transcriptomics and proteomics approach

AIM: To screening key genes related to hepatocellular carcinoma (HCC) metastasis by high-throughput transcriptomics sequencing and serum proteomics.

METHODS: Differentially expressed genes between liver cancer cells Smmc-7721 and normal liver cells L-02 were analyzed by Ion Proton™ high-throughput sequencing. Bioinformatics methods were used to perform GO annotation, clustering and enrichment analysis. Ten serum samples from HCC patients and 10 normal serum samples were recruited to detect the differential protein expression by isobaric tags for relative and absolute quantitation (iTRAQ) and matrix-assisted laser desorption/ionization tandem time of flight mass spectrometry (MALDI-TOF/MS). The transcriptomics data and serum proteomics data were analyzed together to screen key genes related to HCC metastasis. Then, a screened key gene was verified by immunohistochemistry in 76 HCC and adjacent tissues.

RESULTS: A total of 618 differentially expressed genes (DEGs) in liver cancer cells were identified by transcriptome sequencing, and the gene functions were enriched in 14 terms, including metastasis process, transcription and REDOX process, among which metastasis process owned the most DEGs [15.05% (93/618)]. The proteomics data showed that a total of 69 differentially expressed proteins in HCC were detected, including 33 up-regulated and 36 down-regulated ones. Combination analysis found three common factors in transcriptomics and proteomics, among which heat shock protein 90 AA1 (HSP90AA1) was up-regulated in HCC and presented the most significant ratio. According to the immunohistochemical results, the strongly positive rates of HSP90α in HCC with portal vein metastasis and without were 66.7% (16/24) and 25% (13/52), respectively (P < 0.005). HSP90α was overexpressed in HCC with portal vein metastasis.

CONCLUSION: Transcriptomics and proteomics analysis revealed that HSP90AA1 might be a key gene related to HCC metastasis.

The significance of HSP90AA1, HSP90AB1 and HSP90B1 gene polymorphisms in a Turkish population with non-small cell lung cancer

BACKGROUND/AIM

Heat-shock proteins (HSPs) are molecular chaperones which modify the structures and interactions of other proteins. The aim of our study was to investigate HSP90AA1, HSP90AB1 and HSP90B1 gene polymorphisms in patients with non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Ninety-seven patients with NSCLC and 97 healthy controls were included in the study. Real-time polymerase chain reaction was used for genotyping.

RESULTS

The frequency of mutant CC genotype for HSP90AA1 (rs4947C/T), mutant AA genotype for HSP90AB1 (rs13296A/G) and mutant CC genotype for HSP90B1 (rs2070908 C/G) was significantly higher in the patient group than in controls (p=0.019, p=0.004 and p=0.036, respectively). The frequency of patients with homozygote mutant allele was also significantly higher than that of controls and possessing of the mutant genotype increased the risk for disease by approximately 2.9, 4.8, 1.9 for HSP90AA1, HSP90AB1 and HSP90B1, respectively. The present study appears to be the first of its kind to report data on these gene polymorphisms in patients with NSCLC in the Turkish population.