scholarly journals Activation of Chaperon-Mediated Autophagy Via Modulation of Hsp90 Activity Inhibits Tumor Growth Under Hypoxia

2021 ◽  
Author(s):  
Jun-Kyu Byun ◽  
Sun Hee Lee ◽  
Eui Jung Moon ◽  
Myo-Hyeon Park ◽  
Hyeonha Jang ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Tumor Progression ◽  
Cell Biology ◽  
Chaperone Function ◽  
Depth Analysis ◽  
Hsp90 Chaperone ◽  
Hypoxic Tumor

Abstract Background: Chaperon-mediated autophagy (CMA) is a target specific degradation pathway among autophagic processes. Although CMA plays critical roles in tumor progression in general, the role of CMA in tumor progression under hypoxia is poorly understood. We investigated the role of CMA in hypoxic tumor using a novel Hsp90-mediated modulator of CMA.Methods: We examined whether manassantin A (ManA), known as a potent inhibitor of HIF-1α, is a CMA modulator using biochemical, molecular, and cell biology approaches. We analyzed the effects of ManA on Hsp90 chaperone function by using Significant Analysis of Microarray, luciferase refolding assay, HS-10 resin binding assay, NMR spectroscopy, and SPR assay. We investigated tumor growth in response to monotherapy and combination therapy with ManA and anti-programmed death-1 (PD-1) antibody in vivo. To assess the clinical efficacy of CMA-related genes, we analyzed the gene expressions of HIF-1α, HSP90AA1, and transcription factor EB (TFEB) using TCGA datasets. Finally, we assessed in vivo/in vitro absorption, distribution, metabolism, and excretion properties of ManA.Results: ManA inhibits Hsp90 chaperone function through disruption of the Hsp90/F1F0-ATP synthase (chaperone/co-chaperone) complex. The inhibition of Hsp90 enhances the interaction of CMA substrates and LAMP-2A as well as TFEB nuclear localization, thus leading to CMA activation. Importantly, CMA activation not only retards tumor growth in vitro and in vivo, but also displays cooperative antitumor activity with anti-PD-1 antibody in vivo. An in-depth analysis of TCGA datasets shows that combined expression of HSP90AA1High/HIF1AHigh or TFEBLow/HIF1AHigh is strongly correlated with poor prognosis in lung cancer patients. Conclusions: ManA-induced inhibition of Hsp90 promotes CMA activity and decreases the stability of CMA substrates such as HIF-1α protein, leading to a marked reduction of hypoxic tumor growth. Therefore, targeting CMA activity via Hsp90 may present a promising therapeutic strategy for hypoxic tumor.

scholarly journals Blocking the GITR-GITRL pathway to overcome resistance to therapy in sarcomatoid malignant pleural mesothelioma

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Meilin Chan ◽  
Licun Wu ◽  
Zhihong Yun ◽  
Trevor D. McKee ◽  
Michael Cabanero ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Malignant Pleural Mesothelioma ◽  
Neutralizing Antibodies ◽  
Pleural Mesothelioma ◽  
Spheroid Formation ◽  
Resistance To Therapy ◽  
Sarcomatoid Mesothelioma

AbstractMalignant pleural mesothelioma (MPM) is an aggressive neoplasm originating from the pleura. Non-epithelioid (biphasic and sarcomatoid) MPM are particularly resistant to therapy. We investigated the role of the GITR-GITRL pathway in mediating the resistance to therapy. We found that GITR and GITRL expressions were higher in the sarcomatoid cell line (CRL5946) than in non-sarcomatoid cell lines (CRL5915 and CRL5820), and that cisplatin and Cs-137 irradiation increased GITR and GITRL expressions on tumor cells. Transcriptome analysis demonstrated that the GITR-GITRL pathway was promoting tumor growth and inhibiting cell apoptosis. Furthermore, GITR+ and GITRL+ cells demonstrated increased spheroid formation in vitro and in vivo. Using patient derived xenografts (PDXs), we demonstrated that anti-GITR neutralizing antibodies attenuated tumor growth in sarcomatoid PDX mice. Tumor immunostaining demonstrated higher levels of GITR and GITRL expressions in non-epithelioid compared to epithelioid tumors. Among 73 patients uniformly treated with accelerated radiation therapy followed by surgery, the intensity of GITR expression after radiation negatively correlated with survival in non-epithelioid MPM patients. In conclusion, the GITR-GITRL pathway is an important mechanism of autocrine proliferation in sarcomatoid mesothelioma, associated with tumor stemness and resistance to therapy. Blocking the GITR-GITRL pathway could be a new therapeutic target for non-epithelioid mesothelioma.

scholarly journals KLF7/VPS35 axis contributes to hepatocellular carcinoma progression through CCDC85C-activated β-catenin pathway

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yarong Guo ◽  
Bao Chai ◽  
Junmei Jia ◽  
Mudan Yang ◽  
Yanjun Li ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Proliferation ◽  
Tumor Growth ◽  
Luciferase Reporter ◽  
Aberrant Expression ◽  
Proliferation And Invasion ◽  
Hcc Cells

Abstract Objective Dysregulation of KLF7 participates in the development of various cancers, but it is unclear whether there is a link between HCC and aberrant expression of KLF7. The aim of this study was to investigate the role of KLF7 in proliferation and migration of hepatocellular carcinoma (HCC) cells. Methods CCK8, colony growth, transwell, cell cycle analysis and apoptosis detection were performed to explore the effect of KLF7, VPS35 and Ccdc85c on cell function in vitro. Xenografted tumor growth was used to assess in vivo role of KLF7. Chip-qPCR and luciferase reporter assays were applied to check whether KLF7 regulated VPS35 at transcriptional manner. Co-IP assay was performed to detect the interaction between VPS35 and Ccdc85c. Immunohistochemical staining and qRT-PCR analysis were performed in human HCC sampels to study the clinical significance of KLF7, VPS35 and β-catenin. Results Firstly, KLF7 was highly expressed in human HCC samples and correlated with patients’ differentiation and metastasis status. KLF7 overexpression contributed to cell proliferation and invasion of HCC cells in vitro and in vivo. KLF7 transcriptional activation of VPS35 was necessary for HCC tumor growth and metastasis. Further, co-IP studies revealed that VPS35 could interact with Ccdc85c in HCC cells. Rescue assay confirmed that overexpression of VPS35 and knockdown of Ccdc85c abolished the VPS35-medicated promotion effect on cell proliferation and invasion. Finally, KLF7/VPS35 axis regulated Ccdc85c, which involved in activation of β-catenin signaling pathway, confirmed using β-catenin inhibitor, GK974. Functional studies suggested that downregulation of Ccdc85c partly reversed the capacity of cell proliferation and invasion in HCC cells, which was regulated by VPS35 upregulation. Lastly, there was a positive correlation among KLF7, VPS35 and active-β-catenin in human HCC patients. Conclusion We demonstrated that KLF7/VPS35 axis promoted HCC cell progression by activating Ccdc85c-medicated β-catenin pathway. Targeting this signal axis might be a potential treatment strategy for HCC.

scholarly journals Phosphorylation of Serine 11 and Serine 92 as New Positive Regulators of Human Snail1 Function: Potential Involvement of Casein Kinase-2 and the cAMP-activated Kinase Protein Kinase A

2010 ◽  
Vol 21 (2) ◽  
pp. 244-253 ◽  
Author(s):  
Matthew Reid MacPherson ◽  
Patricia Molina ◽  
Serhiy Souchelnytskyi ◽  
Christer Wernstedt ◽  
Jorge Martin-Pérez ◽  
...  
Keyword(s):  
Nuclear Export ◽  
Tumor Metastasis ◽  
Epithelial Mesenchymal Transition ◽  
Cop9 Signalosome ◽  
Mesenchymal Transition ◽  
Depth Analysis ◽  
Positive Regulators

Snail1 is a major factor for epithelial-mesenchymal transition (EMT), an important event in tumor metastasis and in other pathologies. Snail1 is tightly regulated at transcriptional and posttranscriptional levels. Control of Snail1 protein stability and nuclear export by GSK3β phosphorylation is important for Snail1 functionality. Stabilization mechanisms independent of GSK3β have also been reported, including interaction with LOXL2 or regulation of the COP9 signalosome by inflammatory signals. To get further insights into the role of Snail1 phosphorylation, we have performed an in-depth analysis of in vivo human Snail1 phosphorylation combined with mutational studies. We identify new phosphorylation sites at serines 11, 82, and 92 and confirmed previously suggested phosphorylations at serine 104 and 107. Serines 11 and 92 participate in the control of Snail1 stability and positively regulate Snail1 repressive function and its interaction with mSin3A corepressor. Furthermore, serines 11 and 92 are required for Snail1-mediated EMT and cell viability, respectively. PKA and CK2 have been characterized as the main kinases responsible for in vitro Snail1 phosphorylation at serine 11 and 92, respectively. These results highlight serines 11 and 92 as new players in Snail1 regulation and suggest the participation of CK2 and PKA in the modulation of Snail1 functionality.

scholarly journals Hypermethylation of DHRS3 as a Novel Tumor Suppressor Involved in Tumor Growth and Prognosis in Gastric Cancer

2021 ◽  
Vol 9 ◽  
Author(s):  
Sha Sumei ◽  
Kong Xiangyun ◽  
Chen Fenrong ◽  
Sun Xueguang ◽  
Hu Sijun ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Tumor Suppressor ◽  
Tumor Growth ◽  
Human Cancer ◽  
Methylation Status ◽  
Ectopic Expression ◽  
Survival Times

Background/AimsThe role of DHRS3 in human cancer remains unclear. Our study explored the role of DHRS3 in gastric cancer (GC) and its clinicopathological significance and associated mechanisms.MaterialsBisulfite-assisted genomic sequencing PCR and a Mass-Array system were used to evaluate and quantify the methylation levels of the promoter. The expression levels and biological function of DHRS3 was examined by both in vitro and in vivo assays. A two-way hierarchical cluster analysis was used to classify the methylation profiles, and the correlation between the methylation status of the DHRS3 promoter and the clinicopathological characteristics of GC were then assessed.ResultsThe DHRS3 promoter was hypermethylated in GC samples, while the mRNA and protein levels of DHRS3 were significantly downregulated. Ectopic expression of DHRS3 in GC cells inhibited cell proliferation and migration in vitro, decreased tumor growth in vivo. DHRS3 methylation was correlated with histological type and poor differentiation of tumors. GC patients with high degrees of CpG 9.10 methylation had shorter survival times than those with lower methylation.ConclusionDHRS3 was hypermethylated and downregulated in GC patients. Reduced expression of DHRS3 is implicated in gastric carcinogenesis, which suggests DHRS3 is a tumor suppressor.

scholarly journals The critical immunosuppressive effect of MDSC-derived exosomes in the tumor microenvironment

2020 ◽  
Author(s):  
Mohammad H. Rashid ◽  
Thaiz F. Borin ◽  
Roxan Ara ◽  
Raziye Piranlioglu ◽  
Bhagelu R. Achyut ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Microenvironment ◽  
Tumor Growth ◽  
Cd8 T Cells ◽  
Suppressor Cells ◽  
Cell Types ◽  
Biological Macromolecules

AbstractMyeloid-derived suppressor cells (MDSCs) are an indispensable component of the tumor microenvironment (TME), and our perception regarding the role of MDSCs in tumor promotion is attaining extra layer of intricacy in every study. In conjunction with MDSC’s immunosuppressive and anti-tumor immunity, they candidly facilitate tumor growth, differentiation, and metastasis in several ways that yet to be explored. Alike any other cell types, MDSCs also release a tremendous amount of exosomes or nanovesicles of endosomal origin and partake in intercellular communications by dispatching biological macromolecules. There has not been any experimental study done to characterize the role of MDSCs derived exosomes (MDSC exo) in the modulation of TME. In this study, we isolated MDSC exo and demonstrated that they carry a significant amount of proteins that play an indispensable role in tumor growth, invasion, angiogenesis, and immunomodulation. We observed higher yield and more substantial immunosuppressive potential of exosomes isolated from MDSCs in the primary tumor area than those are in the spleen or bone marrow. Our in vitro data suggest that MDSC exo are capable of hyper activating or exhausting CD8 T-cells and induce reactive oxygen species production that elicits activation-induced cell death. We confirmed the depletion of CD8 T-cells in vivo by treating the mice with MDSC exo. We also observed a reduction in pro-inflammatory M1-macrophages in the spleen of those animals. Our results indicate that immunosuppressive and tumor-promoting functions of MDSC are also implemented by MDSC-derived exosomes which would open up a new avenue of MDSC research and MDSC-targeted therapy.

scholarly journals BCAT1 Activates PI3K/AKT/mTOR Pathway and Contributes to the Angiogenesis and Tumorigenicity of Gastric Cancer

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiong Shu ◽  
Pan-Pan Zhan ◽  
Li-Xin Sun ◽  
Long Yu ◽  
Jun Liu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Tumor Growth ◽  
Western Blotting ◽  
Mtor Pathway ◽  
Clinical Samples ◽  
Xenograft Models ◽  
Cell Phenotypes

BackgroundFocusing on antiangiogenesis may provide promising choices for treatment of gastric cancer (GC). This study aimed to investigate the mechanistic role of BCAT1 in the pathogenesis of GC, particularly in angiogenesis.MethodsBioinformatics and clinical samples analysis were used to investigate the expression and potential mechanism of BCAT1 in GC. BGC823 cells with BCAT1 overexpression or silencing were induced by lentiviral transduction. Cell phenotypes and angiogenesis were evaluated. The relevant proteins were quantized by Western blotting, immunohistochemistry, or immunofluorescence. Xenograft models were constructed to confirm the role of BCAT1 in vivo.ResultsBCAT1 was overexpressed in GC patients and associated with lower survival. BCAT1 expression was correlated with proliferation-, invasion-, or angiogenesis-related markers expression and pathways. Silencing BCAT1 expression suppressed cell viability, colony formation, cycle progression, invasion, and angiogenesis of BGC823 cells, as well as the tumor growth of xenograft models, whereas overexpressing BCAT1 had the opposite results both in vitro and in vivo. Bioinformatics analysis and Western blotting demonstrated that BCAT1 activated the PI3K/AKT/mTOR pathway. The addition of LY294002 reversed the tumor growth induced by BCAT1 overexpression, further verifying this mechanism.ConclusionBCAT1 might act as an oncogene by facilitating proliferation, invasion, and angiogenesis through activation of the PI3K/AKT/mTOR pathway. This finding could aid the optimization of antiangiogenesis strategies.

scholarly journals New Actors Driving the Epithelial–Mesenchymal Transition in Cancer: The Role of Leptin

Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1676
Author(s):  
Monserrat Olea-Flores ◽  
Juan C. Juárez-Cruz ◽  
Miriam D. Zuñiga-Eulogio ◽  
Erika Acosta ◽  
Eduardo García-Rodríguez ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Tumor Progression ◽  
Epithelial Mesenchymal Transition ◽  
Migration And Invasion ◽  
Mesenchymal Transition ◽  
Epithelial Cancers ◽  
Patients With Cancer

Leptin is a hormone secreted mainly by adipocytes; physiologically, it participates in the control of appetite and energy expenditure. However, it has also been linked to tumor progression in different epithelial cancers. In this review, we describe the effect of leptin on epithelial–mesenchymal transition (EMT) markers in different study models, including in vitro, in vivo, and patient studies and in various types of cancer, including breast, prostate, lung, and ovarian cancer. The different studies report that leptin promotes the expression of mesenchymal markers and a decrease in epithelial markers, in addition to promoting EMT-related processes such as cell migration and invasion and poor prognosis in patients with cancer. Finally, we report that leptin has the greatest biological relevance in EMT and tumor progression in breast, lung, prostate, esophageal, and ovarian cancer. This relationship could be due to the key role played by the enriched tumor microenvironment in adipose tissue. Together, these findings demonstrate that leptin is a key biomolecule that drives EMT and metastasis in cancer.

The Role of Nucleophosmin In Hematopoietic Stem Cells and the Pathogenesis of Myelodysplastic Syndrome

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 95-95 ◽  
Author(s):  
Keisuke Ito ◽  
Paolo Sportoletti ◽  
John G Clohessy ◽  
Grisendi Silvia ◽  
Pier Paolo Pandolfi
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Myelodysplastic Syndrome ◽  
Cell Biology ◽  
De Novo ◽  
Stem Cell Biology ◽  
Hematopoietic Stem

Abstract Abstract 95 Myelodysplastic syndrome (MDS) is an incurable stem cell disorder characterized by ineffective hematopoiesis and an increased risk of leukemia transformation. Nucleophosmin (NPM) is directly implicated in primitive hematopoiesis, the pathogenesis of hematopoietic malignancies and more recently of MDS. However, little is known regarding the molecular role and function of NPM in MDS pathogenesis and in stem cell biology. Here we present data demonstrating that NPM plays a critical role in the maintenance of hematopoietic stem cells (HSCs) and the transformation of MDS into leukemia. NPM is located on chromosome 5q and is frequently lost in therapy-related and de novo MDS. We have previously shown that Npm1 acts as a haploinsufficient tumor suppressor in the hematopoietic compartment and Npm1+/− mice develop a hematologic syndrome with features of human MDS, including increased susceptibility to leukemogenesis. As HSCs have been demonstrated to be the target of the primary neoplastic event in MDS, a functional analysis of the HSC compartment is essential to understand the molecular mechanisms in MDS pathogenesis. However, the role of NPM in adult hematopoiesis remains largely unknown as Npm1-deficiency leads to embryonic lethality. To investigate NPM function in adult hematopoiesis, we have generated conditional knockout mice of Npm1, using the Cre-loxP system. Analysis of Npm1 conditional mutants crossed with Mx1-Cre transgenic mice reveals that Npm1 plays a crucial role in adult hematopoiesis and ablation of Npm1 in adult HSCs leads to aberrant cycling and followed by apoptosis. Analysis of cell cycle status revealed that HSCs are impaired in their ability to maintain quiescence after Npm1-deletion and are rapidly depleted in vivo as well as in vitro. Competitive reconstitution assay revealed that Npm1 acts cell-autonomously to maintain HSCs. Conditional inactivation of Npm1 leads to an MDS phenotype including a profoundly impaired ability to differentiate into cells of the erythroid lineage, megakaryocyte dyspoiesis and centrosome amplification. Furthermore, Npm1 loss evokes a p53-dependent response and Npm1-deleted HSCs undergo apoptosis in vivo and in vitro. Strikingly, transfer of the Npm1 mutation into a p53-null background rescued the apoptosis of Npm1-ablated HSCs and resulted in accelerated transformation to an aggressive and lethal form of acute myeloid leukemia. Our findings highlight the crucial role of NPM in stem cell biology and identify a new mechanism by which MDS can progress to leukemia. This has important therapeutic implications for de novo MDS as well as therapy-related MDS, which is known to rapidly evolve to leukemia with frequent loss or mutation of TRP53. Disclosures: No relevant conflicts of interest to declare.

The role of ZNF395 in renal cell carcinoma proliferation, migration, and invasion.

2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 592-592 ◽  
Author(s):  
Chen Zhao ◽  
Christopher G. Wood ◽  
Jose A. Karam ◽  
Tapati Maity ◽  
Lei Wang
Keyword(s):  
Renal Cell Carcinoma ◽  
Tumor Growth ◽  
Cell Carcinoma ◽  
Cell Lines ◽  
Renal Cell ◽  
Migration And Invasion ◽  
Mrna Levels

592 Background: Zinc finger protein 395 (ZNF395) is frequently altered in several tumor types. However, the role of ZNF395 remains poorly studied in patients with clear cell renal cell carcinoma (RCC). In this study, we investigated the in vitro and in vivo role of ZNF395 in ccRCC. Methods: cBioPortal For Cancer Genomics was used to correlate the expression of ZNF395 with RCC patient clinical, pathological and molecular profiles. ZNF395 protein and mRNA levels were studied in several RCC cell lines in vitro. Subsequently, ZNF395 knockdown was performed in 786-O and UMRC3 RCC cells and overexpression was done in Caki-1 and 769-P RCC cells. We then evaluated ZNF395 modulation in these cell lines by in vitro MTT, migration and invasion assays. Finally, we studied the effect of ZNF395 knockout and overexpression in vivo using SCID xenograft models. Results: Patients with higher expression of ZNF395 experienced longer disease-free survival and overall survival. Using in vitro models, we confirmed that knockdown of ZNF395 decreased ZNF395 expression, and increased proliferation, migration and invasiveness of 786-O and UMRC3, while overexpression of ZNF395 increased ZNF395 expression, and reduced proliferation, migration and invasiveness of Caki-1 and 769-P. Using in vivo mouse models, knockdown of ZNF395 expression in 786-O promoted tumor growth while its overexpression in Caki-1 resulted in tumor growth inhibition. We are currently performing experiments to understand the process by which ZNF395 regulates ccRCC pathogenesis. Conclusions: Our data support the role of ZNF395 as an important tumor suppressor gene in the pathogenesis of RCC.

scholarly journals Iron, copper and immunocompetence

2007 ◽  
Vol 98 (S1) ◽  
pp. S24-S28 ◽  
Author(s):  
Carlos Muñoz ◽  
Ernesto Rios ◽  
Jorge Olivos ◽  
Oscar Brunser ◽  
Manuel Olivares
Keyword(s):  
Cell Biology ◽  
Respiratory Infections ◽  
The Elderly ◽  
Iron Nutrition ◽  
Immune Functions ◽  
Human Beings ◽  
Additional Information

Microminerals including copper and iron are essential to immunity and health in human beings. The development of powerful tools in analytical cell biology and molecular genetics has facilitated efforts to identify specific cellular and molecular functions of trace elements in the maturation, activation and functions of host defence mechanisms. Selected recent reports about the role of copper and iron nutrition on immune functions are critically analysed here. Effects of trace element supplementation on infectious morbidity are also reviewed. While micromineral deficiencies, in general, may have widespread effects on nearly all components of immune response, these effects can be reversed by supplementation. However, the conflicting effects of iron deficiency and iron supplementationin vitroon the defensive systems reveals the urgent need for further additional information on thein vivosituation. In the elderly, vaccination against respiratory infections is likely to protect only 30–70 % of the population. However, it may be possible to modulate immune function and ultimately reduce the severity of infections through micronutrient supplementation. Thus, microminerals contribute to the maintenance of the balance between immunity and health in humans.

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