The correct folding is a key process for a protein to acquire its functional structure and conformation. Prefoldin is a well-known chaperone protein that regulates the correct folding of proteins. ...Prefoldin plays a crucial role in the pathogenesis of common neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, and Huntington's disease). The important role of prefoldin in emerging fields (such as nanoparticles, biomaterials) and tumors has attracted widespread attention. Also, each of the prefoldin subunits has different and independent functions from the prefoldin complex. It has abnormal expression in different tumors and plays an important role in tumorigenesis and development, especially c-Myc binding protein MM-1. MM-1 can inhibit the activity of c-Myc through various mechanisms to regulate tumor growth. Therefore, an in-depth analysis of the complex functions of prefoldin and their subunits is helpful to understand the mechanisms of protein misfolding and the pathogenesis of diseases caused by misfolded aggregation.
Chemical genetic studies on acetyl-CoA carboxylases (ACCs), rate-limiting enzymes in long chain fatty acid biosynthesis, have greatly advanced the understanding of their biochemistry and molecular ...biology and promoted the use of ACCs as targets for herbicides in agriculture and for development of drugs for diabetes, obesity and cancers. In mammals, ACCs have both biotin carboxylase (BC) and carboxyltransferase (CT) activity, catalyzing carboxylation of acetyl-CoA to malonyl-CoA. Several classes of small chemicals modulate ACC activity, including cellular metabolites, natural compounds, and chemically synthesized products. This article reviews chemical genetic studies of ACCs and the use of ACCs for targeted therapy of cancers.
Aldo-keto reductase 1B10 (AKR1B10) is downregulated in human ulcerative colitis (UC) and colorectal cancer, being a potential pathogenic factor of these diseases. Aldo-keto reductase 1B8 (AKR1B8) is ...the ortholog in mice of human AKR1B10. Targeted AKR1B8 deficiency disrupts homeostasis of epithelial self-renewal and leads to susceptibility to colitis and carcinogenesis. In this study, we found that in AKR1B8 deficient mice, Muc2 expression in colon was diminished, and permeability of colonic epithelium increased. Within 24 h, orally administered FITC-dextran penetrated into mesenteric lymph nodes (MLN) and liver in AKR1B8 deficient mice, but not in wild type controls. In the colon of AKR1B8 deficient mice, neutrophils and mast cells were markedly infiltrated, γδT cells were numerically and functionally impaired, and dendritic cell development was altered. Furthermore, Th1, Th2, and Th17 cells decreased, but Treg and CD8T cells increased in the colon and MLN of AKR1B8 deficient mice. In colonic epithelial cells of AKR1B8 deficient mice, p-AKT (T308 and S473), p-ERK1/2, p-IKBα, p-p65 (S536), and IKKα expression decreased, accompanied with downregulation of IL18 and CCL20 and upregulation of IL1β and CCL8. These data suggest AKR1B8 deficiency leads to abnormalities of intestinal epithelial barrier and immunity in colon.
A new acridone derivative, 2-aminoacetamido-10-(3, 5-dimethoxy)-benzyl-9(10H)-acridone hydrochloride (named 8a) synthesized in our lab shows potent antitumor activity, but the mechanism of action ...remains unclear. Herein, we report the use of an UPLC/Q-TOF MS metabolomic approach to study the effects of three compounds with structures optimized step-by-step, 9(10H)-acridone (A), 10-(3,5-dimethoxy)benzyl-9(10H)-acridone (I), and 8a, on CCRF-CEM leukemia cells and to shed new light on the probable antitumor mechanism of 8a. Acquired data were processed by principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) to identify potential biomarkers. Comparing 8a-treated CCRF-CEM leukemia cells with vehicle control (DMSO), 23 distinct metabolites involved in five metabolic pathways were identified. Metabolites from glutathione (GSH) and glycerophospholipid metabolism were investigated in detail, and results showed that GSH level and the reduced/oxidized glutathione (GSH/GSSG) ratio were significantly decreased in 8a-treated cells, while L-cysteinyl-glycine (L-Cys-Gly) and glutamate were greatly increased. In glycerophospholipid metabolism, cell membrane components phosphatidylcholines (PCs) were decreased in 8a-treated cells, while the oxidative products lysophosphatidylcholines (LPCs) were significantly increased. We further found that in 8a-treated cells, the reactive oxygen species (ROS) and lipid peroxidation product malondialdehyde (MDA) were notably increased, accompanied with decrease of mitochondrial transmembrane potential, release of cytochrome C and activation of caspase-3. Taken together our results suggest that the acridone derivative 8a induces oxidative stress-mediated apoptosis in CCRF-CEM leukemia cells. The UPLC/Q-TOF MS based metabolomic approach provides novel insights into the mechanistic studies of antitumor drugs from a point distinct from traditional biological investigations.
Alpha, beta-unsaturated carbonyls are highly reactive mutagens and carcinogens to which humans are exposed on a daily basis. This study demonstrates that aldo–keto reductase family 1 member B10 ...(AKR1B10) is a critical protein in detoxifying dietary and lipid-derived unsaturated carbonyls. Purified AKR1B10 recombinant protein efficiently catalyzed the reduction to less toxic alcohol forms of crotonaldehyde at 0.90
μM, 4-hydroxynonenal (HNE) at 0.10
μM, trans-2-hexanal at 0.10
μM, and trans-2,4-hexadienal at 0.05
μM, the concentrations at or lower than physiological exposures. Ectopically expressed AKR1B10 in 293T cells eliminated immediately HNE at 1 (subtoxic) or 5
μM (toxic) by converting to 1,4-dihydroxynonene, protecting the cells from HNE toxicity. AKR1B10 protein also showed strong enzymatic activity toward glutathione-conjugated carbonyls. Taken together, our study results suggest that AKR1B10 specifically expressed in the intestine is physiologically important in protecting the host cell against dietary and lipid-derived cytotoxic carbonyls.
Abstract
Background: Intestinal epithelial cells (IECs) are crucial mediators of intestinal immunity. IECs defects may disrupt development and maturation of intestinal immunity. Aldo-keto reductase ...1B10 (AKR1B10) is a regulator of de novo fatty acids synthesis and lipid synthesis by mediating acetyl-CoA carboxylase-α (ACCA) stability. Aldo-keto reductase 1B8 (AKR1B8) is an ortholog in mice of human AKR1B10, which has similar regulatory function in fatty acid/lipid synthesis. AKR1B8 deficiency causes IECs defects in proliferation and self-renewal, which may lead to dysregulation of intestinal immunity.
Methods: AKR1B8 -/- mice mouse stain was produced by homozygous recombination. Immune cells were isolated from colonic lamina propria (cLP) and mesenteric lymph nodes (MLN). Flow cytometry and immunofluorescence staining were applied for immune cell sorting and measurements. Microbiota composition were quantified by next generation sequencing.
Results: AKR1B8 deficiency causes infiltration of neutrophils, mast cells and basophils in the colon. Also, AKR1B8 deficiency causes impaired γδT cells and T helper cells (Th cells) immunity, such as IFNγ, IL17, IL4 or IL22 production, in colon and mesenteric lymph nodes, while enhances distinct arm of CD8 activity and Treg cells. These alterations may be due to the changes of MHCII+ DCs and CD103+ DCs in AKR1B8 deficient mice. Meanwhile, AKR1B8 inhibits the phosphorylation of p-AKT (T308 and S473) and p-ERK (1/2) in IECs, and suppresses the regulation IKKα/NF-κB signaling cascades. Furthermore, AKR1B8 deficiency induces gut microbiota shifts with higher ratio of Firmicutes/Bacteroidetes.
Conclusions: AKR1B8 is a critical mediators for IECs signaling and immune homeostasis. Loss of AKR1B8 in IECs induces Th cells immune deficiency. This study identified a new compensatory mechanism under IECs defects for maintaining intestinal immune homeostasis.
Citation Format: Xin Wang, Deliang Cao. Aldo-keto reductase 1B8 (AKR1B8) deficiency causes intestinal immune deficiency abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 502.
The reversible thiol/disulfide exchange is an important regulatory mechanism of protein enzymatic activity. Many protein enzymes are susceptible to S-thiolation induced by reactive oxygen species ...(ROS); and the glutathione (GSH) and free amino acid cysteine (Cys) are critical cellular thiol anti-oxidants, protecting proteins from irreversible oxidative damage. In this study, we found that aldo–keto reductase family 1 member B10 (AKR1B10) contains 4 Cys residues, i.e., Cys45, Cys187, Cys200, and Cys299. Exposing AKR1B10 to ROS mixtures resulted in significant decrease of its free sulfhydryl groups, up to 40–50% in the presence of physiological thiol cysteine at 0.5 or 1.0 mM; and accordingly, AKR1B10 enzymatic activity was reversibly decreased, in parallel with the oxidation of the sulfhydryl groups. ROS-induced thiolation also affected the sensitivity of AKR1B10 to inhibitors EBPC, epalrestat, and statil. Together our results showed for the first time that AKR1B10's enzymatic activity and inhibitor sensitivity are modulated by thiol/disulfide exchanges.
Aldo-keto reductase family 1 member B10 (AKR1B10), over-expressed in multiple human cancers, might be implicated in cancer development and progression via detoxifying cytotoxic carbonyls and ...regulating fatty acid synthesis. In the present study, we investigated the ortholog of AKR1B10 in mice, an ideal modeling organism greatly contributing to human disease investigations. In the mouse, there are three aldo-keto reductase family 1 subfamily B (AKR1B) members, i.e., AKR1B3, AKR1B7, and AKR1B8. Among them, AKR1B8 has the highest similarity to human AKR1B10 in terms of amino acid sequence, computer-modeled structures, substrate spectra and specificity, and tissue distribution. More importantly, similar to human AKR1B10, mouse AKR1B8 associates with murine acetyl-CoA carboxylase-α and mediates fatty acid synthesis in colon cancer cells. Taken together, our data suggest that murine AKR1B8 is the ortholog of human AKR1B10.
Abstract
Background:
Breast cancer is the second most common cause of female cancer-related death in the United States. Aldo-keto reductase 1B10 (AKR1B10) is a 35-kDa protein that is highly expressed ...in breast cancer in infiltrative and Ductal Carcinoma in Situ (DCIS) stages. Human epidermal growth factor receptor2 (HER2) is a tyrosine kinase receptor which is highly expressed in 15-20% of infiltrative breast cancer but over 60-70 % in DCIS.
Methods:
We targeted AKR1B10 and HER2 expression using AKR1B10 and HER2 expression lentiviruses in a panel of breast cancer cell lines that have different endogenous expression status of AKR1B10 or HER2, including MCF-7(AKR1B10-/HER2 low), ZR-75-1(AKR1B10-/HER2+), MDA-MB-468 (AKR1B10+/HER2-) and the normal human mammary cells MCF10A (AKR1B10-/HER2-). We investigated the effects of AKR1B10 or HER2 expression on cell proliferation, clonogenicity, adhesion, migration, and invasion. Western blots were performed to check integrin α5, δ-catenin expression and the phosphorylation of signaling proteins in Raf/MEK/ERK and AKT/P-mTOR pathways.
Results:
Our data showed that AKR1B10 promoted the proliferation of HER2+ human breast cancer cell. The results of colony forming and soft agar assays demonstrated that AKR1B10 stimulated clonogenic efficiency of HER2+ cells. Also, AKR1B10 promoted HER2+ cells adhesion to extracellular matrix, facilitated their migration and significantly increased their invasion capability. Moreover, it upregulated integrin α5, δ-catenin expression, and promoted HER2+ cells growth and invasiveness through the activation of AKT/mTOR and Raf/MEK/ERK pathways
Conclusion:
AKR1B10 promotes HER2+ human breast cancer cell proliferation and invasiveness.
Citation Format: Ramina Khoshaba, Deliang Cao. Promoting role of AKR1B10 in HER2+ breast cancer at early stage abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3493.
Pokemon is an important proto-oncogene involved in various biological processes and cancer development, such as cell differentiation, tumorigenesis and metastasis. Pokemon is recognized as a ...transcription factor localized upstream of several oncogenes, regulating their expression. p38MAPKs act as key regulatory factors in cellular signaling pathways associated with inflammatory responses, cell proliferation, differentiation and survival. p38β, a member of p38MAPK family, is closely correlated with tumorigenesis, but the mechanism of activation remains unclear. In this study, we found overexpression of Pokemon promoted the growth, migration and invasion of HepG2 cells. However, a p38 inhibitor SB202190 efficiently attenuated the promoting effect of Pokemon in the HepG2 cells. Targeted expression or silencing of Pokemon changed cellular p38β protein level and phosphorylation of downstream ATF2 in the p38 signaling pathway. Both dual luciferase report assay and ChIP assay suggested that p38β is a novel regulatory target of the transcription factor Pokemon and positively regulated by Pokemon in hepatic cells.
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