Glucose-regulated protein 94 mediates progression and metastasis of esophageal squamous cell carcinoma via mitochondrial function and the NF-kB/COX-2/VEGF axis

Methyltransferase Set7/9 as a Multifaceted Regulator of ROS Response

Reactive oxygen species (ROS) induce multiple signaling cascades in the cell and hence play an important role in the regulation of the cell's fate. ROS can cause irreversible damage to DNA and proteins resulting in cell death. Therefore, finely tuned regulatory mechanisms exist in evolutionarily diverse organisms that are aimed at the neutralization of ROS and its consequences with respect to cellular damage. The SET domain-containing lysine methyltransferase Set7/9 (KMT7, SETD7, SET7, SET9) post-translationally modifies several histones and non-histone proteins via monomethylation of the target lysines in a sequence-specific manner. In cellulo, the Set7/9-directed covalent modification of its substrates affects gene expression, cell cycle, energy metabolism, apoptosis, ROS, and DNA damage response. However, the in vivo role of Set7/9 remains enigmatic. In this review, we summarize the currently available information regarding the role of methyltransferase Set7/9 in the regulation of ROS-inducible molecular cascades in response to oxidative stress. We also highlight the in vivo importance of Set7/9 in ROS-related diseases.

Exosome-mediated lnc-ABCA12-3 promotes proliferation and glycolysis but inhibits apoptosis by regulating the toll-like receptor 4/nuclear factor kappa-B signaling pathway in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a kind of malignant tumor with high incidence and mortality in the digestive system. The aim of this study is to explore the function of lnc-ABCA12-3 in the development of ESCC and its unique mechanisms. RT-PCR was applied to detect gene transcription levels in tissues or cell lines like TE-1, EC9706, and HEEC cells. Western blot was conducted to identify protein expression levels of mitochondrial apoptosis and toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) signaling pathway. CCK-8 and EdU assays were carried out to measure cell proliferation, and cell apoptosis was examined by flow cytometry. ELISA was used for checking the changes in glycolysis-related indicators. Lnc-ABCA12-3 was highly expressed in ESCC tissues and cells, which preferred it to be a candidate target. The TE-1 and EC9706 cells proliferation and glycolysis were obviously inhibited with the downregulation of lnc-ABCA12-3, while apoptosis was promoted. TLR4 activator could largely reverse the apoptosis acceleration and relieved the proliferation and glycolysis suppression caused by lnc-ABCA12-3 downregulation. Moreover, the effect of lnc-ABCA12-3 on ESCC cells was actualized by activating the TLR4/NF-κB signaling pathway under the mediation of exosome. Taken together, the lnc-ABCA12-3 could promote the proliferation and glycolysis of ESCC, while repressing its apoptosis probably by regulating the TLR4/NF-κB signaling pathway under the mediation of exosome.

A Pan-Cancer Analysis of Heat-Shock Protein 90 Beta1(HSP90B1) in Human Tumours

Background: HSP90B1, a member of the heat-shock protein 90 family, plays a vital role as a molecular chaperone for oncogenes and stimulates tumour growth. However, its role in various cancers remains unexplored. Methods: Using the cancer genome atlas, gene expression omnibus the Human Protein Atlas databases and various other bioinformatic tools, this study investigated the involvement of HSP90B1 in 33 different tumour types. Results: The over-expression of HSP90B1 generally predicted poor overall survival and disease-free survival for patients with tumours, such as adrenocortical carcinoma, bladder urothelial carcinoma, kidney renal papillary cell carcinoma, and lung adenocarcinoma. In this study, HSP90B1 was highly expressed in the majority of tumours. A comparison was made between the phosphorylation of HSP90B1 in normal and primary tumour tissues, and putative functional mechanisms in HSP90B1-mediated oncogenesis were investigated. Additionally, the mutation burden of HSP90B1 in cancer was evaluated along with the survival rate of patients with cancer patients. Conclusion: This first pan-cancer investigation reveals the oncogenic functions of HSP90B1 in various cancers.

MicroRNA-99a-3p/GRP94 axis affects metastatic progression of human papillary thyroid carcinoma by regulating ITGA2 expression and localization

Papillary thyroid cancer (PTC) usually has favorable prognosis; however, distant metastasis is a leading cause of death associated with PTC. MicroRNA-99a-3p (miR-99a-3p) is a member of the miR-99 family that is shown to be a tumor suppressor in various human cancers including the anaplastic thyroid cancer, another type of thyroid cancer. The Cancer Genome Atlas database and our previous study reported that miR-99a-3p is downregulated in human PTC tissues as well as human papillary thyroid carcinoma B-CPAP and TPC-1 cell lines. However, its pathological role in PTC remains unclear, especially its impact on PTC metastasis. In the present study, the role of miR-99a-3p in PTC metastasis was molecularly evaluated in in vitro and in vivo models. Our functional study revealed that overexpressing miR-99a-3p significantly suppresses epithelial-mesenchymal transition (EMT) and anoikis resistance as well as migration and invasion of B-CPAP and TPC-1 cells. The mechanical study indicated that glucose-regulated protein 94 (GRP94) is the direct target of miR-99a-3p. Moreover, GRP94 overexpression reverses the inhibitory effect of miR-99a-3p on PTC metastasis. In addition, the miR-99a-3p/GRP94 axis exerts its effect via inhibiting the expression and cytoplasmic relocation of integrin 2α (ITGA2). Furthermore, in vivo experiments confirmed that miR-99a-3p significantly inhibits tumor growth and lung metastasis in PTC xenograft mice. Overall, our findings suggested that the miR-99a-3p/GRP94/ITGA2 axis may be a novel therapeutic target for the prevention of PTC metastasis.

Clinicopathologic and Prognostic Association of GRP94 Expression in Colorectal Cancer with Synchronous and Metachronous Metastases

Patients with advanced colorectal cancer (CRC) with distant metastases have a poor prognosis. We evaluated the clinicopathological relevance of GRP94 expression in these cases. The immunohistochemical expression of GRP94 was studied in 189 CRC patients with synchronous (SM; n = 123) and metachronous metastases (MM; n = 66), using tissue microarray; the association between GRP94 expression, outcome, and tumor-infiltrating lymphocytes (TILs) was also evaluated. GRP94 was expressed in 64.6% (122/189) patients with CRC; GRP94 positivity was found in 67.5% and 59.1% patients with SM and MM, respectively. In the SM group, high GRP94 expression was more common in patients with a higher density of CD4+ TILs (p = 0.002), unlike in the MM group. Survival analysis showed that patients with GRP94 positivity had significantly favorable survival (p = 0.030); after multivariate analysis, GRP94 only served as an independent prognostic factor (p = 0.034; hazard ratio, 0.581; 95% confidence interval, 0.351-0.961) in the SM group. GRP94 expression was detected in 49.4% of metastatic sites and showed significant heterogeneity between primary and metastatic lesions (p = 0.012). GRP94 is widely expressed in CRC with distant metastases; its expression was associated with favorable prognosis in the SM group, unlike in the MM group.

Cell Surface GRP94 as a Novel Emerging Therapeutic Target for Monoclonal Antibody Cancer Therapy

Glucose-regulated protein 94 (GRP94) is an endoplasmic reticulum (ER)-resident member of the heat shock protein 90 (HSP90) family. In physiological conditions, it plays a vital role in regulating biological functions, including chaperoning cellular proteins in the ER lumen, maintaining calcium homeostasis, and modulating immune system function. Recently, several reports have shown the functional role and clinical relevance of GRP94 overexpression in the progression and metastasis of several cancers. Therefore, the current review highlights GRP94’s physiological and pathophysiological roles in normal and cancer cells. Additionally, the unmet medical needs of small chemical inhibitors and the current development status of monoclonal antibodies specifically targeting GRP94 will be discussed to emphasize the importance of cell surface GRP94 as an emerging therapeutic target in monoclonal antibody therapy for cancer.

Glucose-Regulated Protein 94 Mediates the Proliferation and Metastasis through the Regulation of ETV1 and MAPK Pathway in Colorectal Cancer

Colorectal cancer (CRC) is a worldwide health problem. Glucose-regulated protein 94 (GRP94) is known as an important endoplasmic reticulum-stress response protein that shows correlation with aggressive cancer behavior. However, the role of GRP94 in CRC is still unclear. Our results showed that silencing GRP94 (GRP94-KD) reduced cell proliferation, invasion and migration of CRC cells and suppressed tumorigenesis in the xenograft mouse model. Rescue assay showed that ETV1 overexpression reversed the effect of GRP94 on cell proliferation and migration. In the molecular mechanism, we found that knockdown of GRP94 inhibited the level of MAPK pathway, including ERK/p-ERK, JNK/p-JNK, and p38/p-p38 signals. Cyclooxygenase-2 and epithelial-mesenchymal transformation biomarkers, such as N-cadherin, vimentin, and β-catenin were suppressed in GRP94 knockdown cells. Treatment of specific inhibitors of MAPK pathway showed that ERK/p-ERK, and p38/p-p38 inhibitors significantly influenced ETV1 expression as compared to JNK/p-JNK inhibitor. Our results indicated that silencing GRP94 repressed the ability of EMT process, cancer cell proliferation, metastasis, and CRC tumorigenesis. Therefore, GRP94 may play an important role in CRC by regulating ETV1 and MAPK pathway.

Effects of Coriandrum sativum on Migration and Invasion Abilities of Cancer Cells

Coriandrum sativum (coriander) is an annual herb in the Apiaceae family. Its leaves and seeds are used for cooking. Coriander has several beneficial functions such as anti-inflammatory, analgesic and anti-cancer effects. Although anti-carcinogenic potential of coriander has been known well, the effects of coriander on cancer metastasis have not yet been fully elucidated. In the present study, the effects of coriander on migration and invasion were investigated in vitro and in vivo by using human hepatocellular carcinoma cell line (HepG2) and mouse melanoma cell line (B16F10). The migration and invasion abilities of cancer cells had been evaluated by trans-well double chamber and these abilities were significantly impaired by treatment of cancer cells with coriander extract whose concentration did not affect proliferation. The treatment of cancer cells with coriander extract significantly reduced both matrix metalloproteinase 2 (MMP-2) and urokinase-type plasminogen activator (u-PA) activities, which were involved in cell migration and invasion, in their conditioned media. Furthermore, coriander extract suppressed the phosphorylation of Erk 1 or IkB in B16F10 cells, and inhibited the expression of MMP-2 or u-PA mRNA. After injection of B16F10 cells into the tail vein of C57BL/6J mice, the number of metastatic regions in lungs were counted. Mice fed with diet containing coriander possessed a smaller number of metastatic regions than those fed with control diet. It was suggested that coriander extract might have the abilities to suppress cancer cell migration and invasion, indicating that coriander provides the improvement of cancer prognosis.

ZenoFishDb v1.1: A Database for Xenotransplantation Studies in Zebrafish

Rapidly accumulating literature has proven feasibility of the zebrafish xenograft models in cancer research. Nevertheless, online databases for searching the current zebrafish xenograft literature are in great demand. Herein, we have developed a manually curated database, called ZenoFishDb v1.1 (https://konulab.shinyapps.io/zenofishdb), based on R Shiny platform aiming to provide searchable information on ever increasing collection of zebrafish studies for cancer cell line transplantation and patient-derived xenografts (PDXs). ZenoFishDb v1.1 user interface contains four modules: DataTable, Visualization, PDX Details, and PDX Charts. The DataTable and Visualization pages represent xenograft study details, including injected cell lines, PDX injections, molecular modifications of cell lines, zebrafish strains, as well as technical aspects of the xenotransplantation procedures in table, bar, and/or pie chart formats. The PDX Details module provides comprehensive information on the patient details in table format and can be searched and visualized. Overall, ZenoFishDb v1.1 enables researchers to effectively search, list, and visualize different technical and biological attributes of zebrafish xenotransplantation studies particularly focusing on the new trends that make use of reporters, RNA interference, overexpression, or mutant gene constructs of transplanted cancer cells, stem cells, and PDXs, as well as distinguished host modifications.

KLF5-mediated COX2 upregulation contributes to tumorigenesis driven by PTEN deficiency

Tumor suppressor gene PTEN is frequently mutated in a wide variety of cancers. However, the downstream targets or signal transduction pathways of PTEN remain not fully understood. By analyzing Pten-null mouse embryonic fibroblasts (MEFs) cell lines and their isogenic counterparts, we showed that loss of PTEN led to increased cyclooxygenase2 (COX2) expression in an AKT-independent manner. Moreover, we demonstrated that PTEN deficiency promotes the transcription of COX2 via upregulation of the transcription factor Krüppel-like factor 5 (KLF5). Knocked down the expression of COX2 suppressed proliferation, migration and tumoral growth of Pten-null cells. Further experiments revealed that COX2 enhanced Pten-null MEFs growth and migration through upregulation of NADPH oxidase 4 (NOX4). In addition, MK-2206, a specific inhibitor of AKT, in combination with celecoxib, a COX2 inhibitor, strongly inhibited Pten-deficient cell growth. We concluded that KLF5/COX2/NOX4 signaling pathway is critical for cell growth and migration caused by the loss of PTEN, and the combination of MK-2206 and celecoxib may be an effective new approach to treating PTEN deficiency related tumors.

Prognostic significance of glucose-related protein 94 in colorectal cancer

AIMS

The expression of glucose-related protein 94 (GRP94), a member of the heat shock protein 90 family, was correlated with a variety of clinicopathological factors and patient survival in a large colorectal cancer (CRC) cohort. We aimed to elucidate the role of GRP94 in the prognosis of CRC patients.

METHODS

Tissue microarray blocks were generated from 709 CRC samples and immunohistochemically stained for GRP94.

RESULTS

Of the 709 tumours, 164 (23.1%) and 545 (76.9%) were classified in the low and high expression groups, respectively. GRP94 expression was high in CRC cases with larger tumours (p =  0.005) and advanced pT stage (p =  0.021). GRP94 expression was higher in females than males (p =  0.024). In univariate and multivariate survival analyses, high GRP94 expression was unexpectedly associated with better overall survival in CRC patients younger than 65 years of age (p =  0.001) CONCLUSION: Our conflicting results indicate that GRP94 has the ability to switch between oncogenic and tumour-suppressive roles depending on the conditions and microenvironment of the tumour cells. Furthermore, GRP94 could be a candidate biomarker to predict better prognosis in CRC patients.

GM2-GM3 gangliosides ratio is dependent on GRP94 through down-regulation of GM2-AP cofactor in brain metastasis cells

GRP94 is an ATP-dependent chaperone able to regulate pro-oncogenic signaling pathways. Previous studies have shown a critical role of GRP94 in brain metastasis (BrM) pathogenesis and progression. In this work, an untargeted lipidomic analysis revealed that some lipid species were altered in GRP94-deficient cells, specially GM2 and GM3 gangliosides. The catalytic pathway of GM2 is affected by the low enzymatic activity of β-Hexosaminidase (HexA), responsible for the hydrolysis of GM2 to GM3. Moreover, a deficiency of the GM2-activator protein (GM2-AP), the cofactor of HexA, is observed without alteration of gene expression, indicating a post-transcriptional alteration of GM2-AP in the GRP94-ablated cells. One plausible explanation of these observations is that GM2-AP is a client of GRP94, resulting in defective GM2 catabolic processing and lysosomal accumulation of GM2 in GRP94-ablated cells. Overall, given the role of gangliosides in cell surface dynamics and signaling, their imbalance might be linked to modifications of cell behaviour acquired in BrM progression. This work indicates that GM2-AP could be an important factor in ganglioside balance maintenance. These findings highlight the relevance of GM3 and GM2 gangliosides in BrM and reveal GM2-AP as a promising diagnosis and therapeutic target in BrM research.

GRP94 Is Involved in the Lipid Phenotype of Brain Metastatic Cells

Metabolic adaptation may happen in response to the pressure exerted by the microenvironment and is a key step in survival of metastatic cells. Brain metastasis occurs as a consequence of the systemic dissemination of tumor cells, a fact that correlates with poor prognosis and high morbidity due to the difficulty in identifying biomarkers that allow a more targeted therapy. Previously, we performed transcriptomic analysis of human breast cancer patient samples and evaluated the differential expression of genes in brain metastasis (BrM) compared to lung, bone and liver metastasis. Our network approach identified upregulation of glucose-regulated protein 94 (GRP94) as well as proteins related to synthesis of fatty acids (FA) in BrM. Here we report that BrM cells show an increase in FA content and decreased saturation with regard to parental cells measured by Raman spectroscopy that differentiate BrM from other metastases. Moreover, BrM cells exerted a high ability to oxidize FA and compensate hypoglycemic stress due to an overexpression of proteins involved in FA synthesis and degradation (SREBP-1, LXRα, ACOT7). GRP94 ablation restored glucose dependence, down-regulated ACOT7 and SREBP-1 and decreased tumorigenicity in vivo. In conclusion, GRP94 is required for the metabolic stress survival of BrM cells, and it might act as a modulator of lipid metabolism to favor BrM progression.

Co-downregulation of GRP78 and GRP94 Induces Apoptosis and Inhibits Migration in Prostate Cancer Cells

Background

Both glucose-regulated protein 78 kDa (GRP78) and glucose-regulated protein 94 kDa (GRP94) are important molecular chaperones that play critical roles in maintaining tumor survival and progression. This study investigated the effects in prostate cancer cells following the downregulation of GRP78 and GRP94.

Methods

RNA interference was used to downregulate GRP78 and GRP94 expression in the prostate cancer cell line, PC-3. The effects on apoptosis and cell migration was examined along with expression of these related proteins.

Results

Small interfering RNAs targeting GRP78 and GRP94 successfully down-regulated their expression. This resulted in the induction of apoptosis and inhibition of cell migration. Preliminary mechanistic studies indicated that caspase-9 (cleaved) and Bax expression levels were upregulated while Bcl-2 and vimentin expression levels were downregulated.

Conclusion

Co-downregulation of GRP78 and GRP94 expression induces apoptosis and inhibits migration in prostate cancer cells.

The clinical and prognostic evaluation of GRP94 immunoexpression in Caucasian patients with colorectal adenocarcinoma

Introduction

Colorectal cancer (CRC) is traditionally regarded as the most commonly diagnosed gastrointestinal malignant disease. Nevertheless, despite advances in diagnosis and novel therapeutic options, the clinical outcomes of patients are still unsatisfactory.

Aim

To investigate the clinicopathological and prognostic roles of GRP94 expression, the immunohistochemical investigation was performed on samples of CRC tumour tissues, adjacent non-pathological mucosa, and metastatic foci in regional lymph nodes in Caucasian patients.

Material and methods

Paraffin-embedded adenocarcinoma samples were assessed immunohistochemically for GRP94 protein and scored according to the percentage of cells with positive reaction combined with staining intensity. Connections between GRP94 immunoexpression and clinicopathological factors including the overall survival (OS) were evaluated.

Results

The level of the GRP94 immunohistochemical reactivity was correlated with the grade of the histological differentiation (H (2.92) = 25.906; p < 0.001), size of the primary tumour (Z = –4.010; p < 0.001), regional lymph node involvement (Z = –6.547; p < 0.001), and perineural invasion (Z = –6.235; p < 0.001). Kaplan-Meier survival analysis showed that the survival time for patients with a low expression of GRP94 was significantly longer than that for patients with a moderate or strong level of GRP94 immunoreactivity (p < 0.001).

Conclusions

An enhanced level of GRP94 immunoexpression was significantly associated with malignancy-related clinicopathological factors and reduced the 5-year overall survival in CRC patients. However, a multivariate analysis demonstrated that GRP94 was not revealed as an independent risk factor for CRC prognosis.