Role of Receptor for Advanced Glycation End Products (RAGE) and Its Ligands in Cancer Risk

Mechanism of drug-pairs Astragalus Mongholicus-Largehead Atractylodes on treating knee osteoarthritis investigated by GEO gene chip with network pharmacology and molecular docking

Investigations into the therapeutic potential of Astragalus Mongholicus (AM, huáng qí) and Largehead Atractylodes (LA, bái zhú) reveal significant efficacy in mitigating the onset and progression of knee osteoarthritis (KOA), albeit with an elusive mechanistic understanding. This study delineates the primary bioactive constituents and their molecular targets within the AM-LA synergy by harnessing the comprehensive Traditional Chinese Medicine (TCM) network databases, including TCMSP, TCMID, and ETCM. Furthermore, an analysis of 3 gene expression datasets, sourced from the gene expression omnibus database, facilitated the identification of differential genes associated with KOA. Integrating these findings with data from 5 predominant databases yielded a refined list of KOA-associated targets, which were subsequently aligned with the gene signatures corresponding to AM and LA treatment. Through this alignment, specific molecular targets pertinent to the AM-LA therapeutic axis were elucidated. The construction of a protein-protein interaction network, leveraging the shared genetic markers between KOA pathology and AM-LA intervention, enabled the identification of pivotal molecular targets via the topological analysis facilitated by CytoNCA plugins. Subsequent GO and KEGG enrichment analyses fostered the development of a holistic herbal-ingredient-target network and a core target-signal pathway network. Molecular docking techniques were employed to validate the interaction between 5 central molecular targets and their corresponding active compounds within the AM-LA complex. Our findings suggest that the AM-LA combination modulates key biological processes, including cellular activity, reactive oxygen species modification, metabolic regulation, and the activation of systemic immunity. By either augmenting or attenuating crucial signaling pathways, such as MAPK, calcium, and PI3K/AKT pathways, the AM-LA dyad orchestrates a comprehensive regulatory effect on immune-inflammatory responses, cellular proliferation, differentiation, apoptosis, and antioxidant defenses, offering a novel therapeutic avenue for KOA management. This study, underpinned by gene expression omnibus gene chip analyses and network pharmacology, advances our understanding of the molecular underpinnings governing the inhibitory effects of AM and LA on KOA progression, laying the groundwork for future explorations into the active components and mechanistic pathways of TCM in KOA treatment.

Human intestine and placenta exhibit tissue-specific expression of RAGE isoforms

The receptor for advanced glycation end products (RAGE) is encoded by AGER, a gene that is subjected to tissue-specific alternative splicing. Splice variants of RAGE in intestine and placenta are unknown and contradictory data concerning RAGE protein expression in these tissues have been published. As a basis for future functional studies, we examined RAGE expression in small intestine, colon and placentas. PCR cloning revealed that full-length RAGE is the only RAGE transcript isoform expressed in placenta. In the small intestine, the major transcript isoform detected was RAGE_v1 encoding the C-terminally truncated soluble receptor. In the colon, both full-length RAGE as well as several splice variants were identified. Four antibodies were used to study protein expression by immunoblotting and were carefully validated. Appropriate controls were essential to avoid misinterpretation of bands caused by non-specific reactivity of antibodies. Only one of four antibodies tested detected full-length RAGE in placenta, whereas no RAGE-specific band was detected in intestinal tissues despite loading >30-fold more intestinal tissue than the positive control, human lung. RAGE expression levels in the placenta were 100-fold lower compared with human lung when analyzed by ELISA, and no significant differences in RAGE expression were detected between healthy placentas and placentas from women with preeclampsia, gestational diabetes mellitus, or fetal growth restriction. We conclude that healthy placental chorionic tissue expresses low levels of full-length RAGE, whereas expression of the tissue-specific intestinal isoforms is below the limit of detection. Low RAGE expression levels in combination with a lack of antibody validation may explain the conflicting published results on RAGE protein expression in intestine and placenta.

Diagnostic Utility and Tendency of Bronchial and Serum Soluble Receptor for Advanced Glycation EndProducts (sRAGE) in Lung Cancer

The receptor for advanced glycation end-products (RAGE) may serve as a diagnostic and prognostic biomarker of lung cancer and lung injury. We explored whether the serum and bronchial levels of soluble RAGE (sRAGE) distinguished infectious lung diseases from lung cancer. We collected serum and bronchial washing fluids (BWFs) from patients diagnosed with pneumonia, tuberculosis, or preoperative lung cancer from April 2016 to March 2022. sRAGE levels were measured using an enzyme-linked immunosorbent assay and we drew receiver operating characteristic (1) curves to determine the cut-off values affording the best diagnostic sensitivities. We enrolled 81 patients including 20 with tuberculosis, 30 with pneumonia, and 31 with lung cancer. Of the 81, 61% were males and the median age was 66 years. The median serum level of sRAGE was 822 (678-1168 pg/mL) and did not differ significantly between the three groups. The median bronchial sRAGE level was 167 (83-529 pg/mL) but 231 (108-649 pg/mL) for tuberculosis, 366 (106-706 pg/mL) for pneumonia, and 103 (32-254 pg/mL) for lung cancer patients (p = 0.018). The ROC curve for the bronchial sRAGE values of lung cancer patients revealed that the optimal cut-off was 118.9 pg/mL. This afforded a sensitivity of 76%, a specificity of 58%, and an area under the ROC curve of 0.695 (p = 0.005). The level of bronchial sRAGE differed significantly between patients with lung cancer and other respiratory diseases; that level may serve as an auxiliary diagnostic biomarker.

Methylglyoxal and Its Adducts: Induction, Repair, and Association with Disease

Metabolism is an essential part of life that provides energy for cell growth. During metabolic flux, reactive electrophiles are produced that covalently modify macromolecules, leading to detrimental cellular effects. Methylglyoxal (MG) is an abundant electrophile formed from lipid, protein, and glucose metabolism at intracellular levels of 1-4 μM. MG covalently modifies DNA, RNA, and protein, forming advanced glycation end products (MG-AGEs). MG and MG-AGEs are associated with the onset and progression of many pathologies including diabetes, cancer, and liver and kidney disease. Regulating MG and MG-AGEs is a potential strategy to prevent disease, and they may also have utility as biomarkers to predict disease risk, onset, and progression. Here, we review recent advances and knowledge surrounding MG, including its production and elimination, mechanisms of MG-AGEs formation, the physiological impact of MG and MG-AGEs in disease onset and progression, and the latter in the context of its receptor RAGE. We also discuss methods for measuring MG and MG-AGEs and their clinical application as prognostic biomarkers to allow for early detection and intervention prior to disease onset. Finally, we consider relevant clinical applications and current therapeutic strategies aimed at targeting MG, MG-AGEs, and RAGE to ultimately improve patient outcomes.

Strategies for Efficient Targeting of Tumor Collagen for Cancer Therapy

Simple Summary

The tumor microenvironment encompasses the cellular and extracellular matrix components that support and shape the three-dimensional framework in which solid tumors develop and grow. The extracellular matrix of the tumor is characterized by increased deposition and aberrant architecture of collagen fibers. Therefore, as a key mechanical component of the tumor microenvironment, collagen plays a critical role in cancer progression, metastasis, and therapeutic response. To boost the efficacy of current anticancer therapies, including immunotherapy, innovative approaches should take into account strategies directed against the dysregulated non-cancer cell stromal components. In the current review, we provide an overview of the principal approaches to target tumor collagen to provide therapeutic benefits.

Abstract

The tumor stroma, which comprises stromal cells and non-cellular elements, is a critical component of the tumor microenvironment (TME). The dynamic interactions between the tumor cells and the stroma may promote tumor progression and metastasis and dictate resistance to established cancer therapies. Therefore, novel antitumor approaches should combine anticancer and anti-stroma strategies targeting dysregulated tumor extracellular matrix (ECM). ECM remodeling is a hallmark of solid tumors, leading to extensive biochemical and biomechanical changes, affecting cell signaling and tumor tissue three-dimensional architecture. Increased deposition of fibrillar collagen is the most distinctive alteration of the tumor ECM. Consequently, several anticancer therapeutic strategies have been developed to reduce excessive tumor collagen deposition. Herein, we provide an overview of the current advances and challenges of the main approaches aiming at tumor collagen normalization, which include targeted anticancer drug delivery, promotion of degradation, modulation of structure and biosynthesis of collagen, and targeting cancer-associated fibroblasts, which are the major extracellular matrix producers.

ImmunoPET: Antibody-Based PET Imaging in Solid Tumors

Immuno-positron emission tomography (immunoPET) is a molecular imaging modality combining the high sensitivity of PET with the specific targeting ability of monoclonal antibodies. Various radioimmunotracers have been successfully developed to target a broad spectrum of molecules expressed by malignant cells or tumor microenvironments. Only a few are translated into clinical studies and barely into clinical practices. Some drawbacks include slow radioimmunotracer kinetics, high physiologic uptake in lymphoid organs, and heterogeneous activity in tumoral lesions. Measures are taken to overcome the disadvantages, and new tracers are being developed. In this review, we aim to mention the fundamental components of immunoPET imaging, explore the groundbreaking success achieved using this new technique, and review different radioimmunotracers employed in various solid tumors to elaborate on this relatively new imaging modality.

A Novel Defined Hypoxia-Related Gene Signature for Prognostic Prediction of Patients With Ewing Sarcoma

The therapeutic strategy of Ewing sarcoma (EWS) remains largely unchanged over the past few decades. Hypoxia is reported to have an impact on tumor cell progression and is regarded as a novel potential therapeutic target in tumor treatment. This study aimed at developing a prognostic gene signature based on hypoxia-related genes (HRGs). EWS patients from GSE17674 in the GEO database were analyzed as a training cohort, and differently expressed HRGs between tumor and normal samples were identified. The univariate Cox regression, Least Absolute Shrinkage and Selection Operator (LASSO) and multivariate Cox regression analyses were used in this study. A total of 57 EWS patients from the International Cancer Genome Consortium (ICGC) database were set as the validation cohort. A total of 506 differently expressed HRGs between tumor and normal tissues were identified, among which 52 were associated with the prognoses of EWS patients. Based on 52 HRGs, EWS patients were divided into two molecular subgroups with different survival statuses. In addition, a prognostic signature based on 4 HRGs (WSB1, RXYLT1, GLCE and RORA) was constructed, dividing EWS patients into low- and high-risk groups. The 2-, 3- and 5-years area under the receiver operator characteristic curve of this signature was 0.913, 0.97 and 0.985, respectively. It was found that the survival rates of patients in the high-risk group were significantly lower than those in the low-risk group (p < 0.001). The risk level based on the risk score could serve as an independent clinical factor for predicting the survival probabilities of EWS patients. Additionally, antigen-presenting cell (APC) related pathways and T cell co-inhibition were differently activated in two risk groups, which may result in different prognoses. CTLA4 may be an effective immune checkpoint inhibitor to treat EWS patients. All results were verified in the validation cohort. This study constructed 4-HRGs as a novel prognostic marker for predicting survival in EWS patients.

Increased Urinary Levels of Pentosidine Measured by a Newly Developed Enzyme-Linked Immunosorbent Assay Are Independently Correlated with Fracture After Fall

Although we have found that increased serum levels of glyceraldehyde-derived advanced glycation end products (AGEs) are associated with numerous aging-related disorders, it remains unclear which structurally distinct AGEs could be a reliable biomarker of the healthy life-threatening disorders. Since pentosidine is produced by glyceraldehyde, we measured here urinary pentosidine levels with a newly developed enzyme-linked immunosorbent assay (ELISA) kit, which requires no pretreatment with acid hydrolysis and heat, and examined their correlations with geriatric syndrome, such as musculoskeletal disease, frailty, and cognitive impairment, in a general population. Multiple regression analysis revealed that female, age, history of fracture after fall, and taking medication for diabetes were independent correlates of log urine pentosidine-to-creatinine ratio (R² = 0.190). When gender-adjusted log urine pentosidine-to-creatinine ratio stratified by smile frequency grade was compared using analysis of covariance, urine pentosidine-to-creatinine ratio was significantly decreased according to the increase in smile frequency. Our present findings suggest that measurement of urine pentosidine-to-creatinine ratio by a newly developed ELISA kit may be useful for identifying high-risk patients for fall-related fractures.

Pigment epithelium-derived factor inhibits advanced glycation end product-induced proliferation, VEGF and MMP-9 expression in breast cancer cells via interaction with laminin receptor

Pigment epithelium-derived factor (PEDF) is one of the adipocytokines with multifaceted functions, which may serve a role in the development of various types of cardiometabolic disorders. Advanced glycation end products (AGEs) have been shown to contribute to numerous aging-associated disorders, such as cancer. However, it remains unclear whether and how PEDF exerts antitumor effects in AGE-exposed human breast cancer MCF-7 cells, and therefore this was explored in the present study. NADPH oxidase activity was measured with luciferase assay, while gene and protein expression levels were evaluated with quantitative PCR and western blot analysis, respectively. AGEs significantly increased NADPH oxidase-driven superoxide generation, cytochrome b-245 β chain (gp91phox) and receptor for AGE (RAGE) mRNA expression, proliferation, mRNA and protein expression levels of vascular endothelial growth factor (VEGF), and matrix metalloproteinase (MMP)-9 mRNA expression in MCF-7 cells, all of which were dose-dependently inhibited by PEDF. Neutralizing antibody against laminin receptor (LR-Ab) significantly blocked these beneficial effects of PEDF in AGE-exposed MCF-7 cells. Furthermore, as in AGE-treated cells, PEDF dose-dependently inhibited the NADPH oxidase-driven superoxide generation, gp91phox, RAGE and MMP-9 mRNA expression, proliferation, mRNA and protein expression levels of VEGF in non-treated control MCF-7 cells, and these effects were also reversed by LR-Ab. LR levels were not affected by the treatment with AGEs, PEDF or LR-Ab. The present study suggested that PEDF may exert antitumor effects in AGE-exposed breast cancer cells by suppressing NADPH oxidase-induced ROS generation and VEGF and MMP-9 expression via interaction with LR. Since PEDF expression is decreased in breast cancer tissues, pharmacological upregulation or restoration of PEDF may inhibit the growth and metastasis of breast cancer.

Inhibitory Effect of Multimodal Nanoassemblies against Glycative and Oxidative Stress in Cancer and Glycation Animal Models

In recent years, there has been a progress in the study of glycation reaction which is one the possible reason for multiple metabolic disorders. Glycation is a nonenzymatic reaction between nucleic acids, lipids, and proteins resulting into the formation of early glycation products that may further lead to the accumulation of advanced glycation end products (AGEs). The precipitation of AGEs in various cells, tissues, and organs is one of the factors for the initiation and progression of various metabolic derangements including the cancer. The AGE interaction with its receptor "RAGE" activates the inflammatory pathway; yet, the downregulation of RAGE and its role in these pathways are not clear. We explore the effect of anticancer novel nanoassemblies on AGEs to determine its role in the regulation of the expression of RAGE, NFƙB, TNF-α, and IFN-γ. This paper is based on the in vivo and in vitro study in glycation and lung cancer model systems. Upon the treatment of nanoassemblies in both the model systems, we observed a protective effect of nanoassemblies over the inhibition of glycative and oxidative stress via mRNA expression analysis. The mRNA expression results corroborated with the reactive oxygen species (ROS), carboxy-methyl-lysine (CML), and fluorescence studies. In this study, we found that the presence of common factors for glycation and lung cancer is oxidative and glycative stress. This oxidation and glycation might be responsible for the initiation of inflammation which may further lead to uncontrolled growth of cells leading to cancer. This can be a strong association between lung cancer and glycation reaction. The intervention of the anticancer and antiglycation effects of multimodal nanoassemblies throughout the study promises a new pathway for cancer research.

Protective effects of luteolin on nephrotoxicity induced by long-term hyperglycaemia in rats

Objective

This study aimed to investigate whether luteolin delays the progress of diabetic nephropathy (DN) induced by streptozotocin.

Methods

Fifty-three healthy, 8-week-old, male Sprague–Dawley rats were randomly divided into the control (n = 6), model (n = 23), and experimental groups (n = 24). The rat model of diabetic nephropathy was established by intraperitoneal injection of streptozotocin. Rats in the experimental group were administered luteolin suspension of 80 mg/kg daily for 8 weeks. Blood glucose levels and body weight were recorded until the fourth week. After intragastric administration, blood flow and the protective effect of luteolin on diabetic nephropathy were evaluated.

Results

The degree of renal apoptosis and fibrosis in the experimental group was milder, and glomerular structure was more complete compared with the model group. Nphs2 staining suggested that luteolin delayed apoptosis and deletion and fusion of podocytes under high glucose levels, and protected the filtration function of the basement membrane by upregulating Nphs2 protein expression. Time intensity curve results suggested that luteolin delayed deterioration of renal haemodynamics under hyperglycaemia.

Conclusions

This study shows that luteolin delays progression of diabetic nephropathy. This drug has potential wide applicability in future clinical application.

Perspectives on signaling for biological- and processed food-related advanced glycation end-products and its role in cancer progression

Receptor for advanced glycation end-products (RAGE) is a multifunctional receptor binds a broad spectrum of ligands and mediates responses to cell damage and stress conditions. It also activates programs leading to acute and chronic inflammation and implicated in several pathological diseases, including cancer. In this review, we presented the non-enzymatic reaction of reducing sugar with the amino groups of proteins, lipids, and nucleic acids. This reaction initiates a complex series of rearrangements and dehydrations, and then produces a class of irreversibly cross-linked heterogeneous fluorescent moieties, termed advanced glycation end products (AGEs). There is a growing body of evidence that interaction of processes food-related AGEs with a cell surface receptor RAGE brings out the generation of oxidative stress and subsequently evokes proliferative, angiogenic and inflammatory reactions, thereby being involved in the development and progression of various types of cancers. This review is an insightful assessment of molecular mechanisms through which RAGE signaling contributes to the enhancement and survival of the tumorigenic cell. Here we summarize the procurement of individual ligands of RAGE like amphoterin, calcium-binding proteins, and resultant mediation of RAGE signaling pathway, which partially can elucidate the elevated risk of several cancers. Besides, we summarize many factors or conditions including APE1 (apurinic/apyrimidinic endonuclease 1), retinol mutations, retinoblastoma (Rb), proteinase 3 (PR3) hypoxia and so on through which RAGE signaling presents an establishment of cancerous environment. Additionally, we also reviewed some recent findings that give shreds of evidence for presenting the role of RAGE and its ligands in the advanced stage of cancers.

Autophagy-dependent ferroptosis drives tumor-associated macrophage polarization via release and uptake of oncogenic KRAS protein

KRAS is the most frequently mutated oncogene in human neoplasia. Despite a large investment to understand the effects of KRAS mutation in cancer cells, the direct effects of the oncogenetic KRAS activation on immune cells remain elusive. Here, we report that extracellular KRASG12D is essential for pancreatic tumor-associated macrophage polarization. Oxidative stress induces KRASG12D protein release from cancer cells succumbing to autophagy-dependent ferroptosis. Extracellular KRASG12D packaged into exosomes then is taken up by macrophages through an AGER-dependent mechanism. KRASG12D causes macrophages to switch to an M2-like pro-tumor phenotype via STAT3-dependent fatty acid oxidation. Consequently, the disruption of KRASG12D release and uptake can abolish the macrophage-mediated stimulation of pancreatic adenocarcinomas in mouse models. Importantly, the level of KRASG12D expression in macrophages correlates with poor survival in pancreatic cancer patients. These findings not only identify extracellular KRASG12D as a key mediator of cancer cell-macrophage communication, but also provide a novel KRAS-targeted anticancer strategy. Abbreviations: DAMP, damage-associated molecular pattern; PBMCMs, peripheral blood mononuclear cell-derived macrophages; PDAC, pancreatic ductal adenocarcinoma; s.c., subcutaneously; TAMs, tumor-associated macrophages; TME, tumor microenvironment.

Saliva-omics in plasma cell disorders- Proof of concept and potential as a non-invasive tool for monitoring disease burden

Multiple Myeloma (MM), the second most common lymphoid cancer worldwide, is characterised by the uninhibited proliferation of terminally differentiated B-lymphocytes. Leading to The diagnosis typically requires the presence of a monoclonal protein (M protein) and the demonstration of CRAB features (hypercalcemia, renal impairment, anaemia and bone lesions). MM is considered incurable as, due to serial clonal evolution, the vast majority of patients succumb to treatment-refractory disease. MGUS (Monoclonal Gammopathy of Unknown Uncertain Significance) is the pre-malignant form of MM and, although 93% of MM patients exhibit M protein production associated with MGUS before diagnosis, little is known about the switch from pre-malignant to malignant disease. To explore this disease transition further, LC-MS/MS analysis was carried out to identify potential salivary biomarkers to monitor disease burden. FABP5 was detected in saliva as having a significant increase in abundance when MGUS was compared to symptomatic MM. The levels of FABP5 decreased after treatment indicating correlation with tumour burden. This finding was validated using western blot analysis and ELISA analysis. SIGNIFICANCE: The field of biomarker discovery has focused largely on serum as a biofluid. Saliva is a readily available biofluid that, as a biomarker resource, has been relatively un-explored. The identification of changes in saliva indicating disease progression underlines the utility of saliva as a non-invasive source of informative biomarkers reflecting disease burden and progression.

Vitamin D and advanced glycation end products and their receptors

Advanced glycation end products (AGEs) are destructive molecules in the body that, at high levels, contribute to the progression of various chronic diseases. Numerous studies have suggested a modifying effect of vitamin D on AGEs and their receptors. This study sought to summarize the effects of vitamin D on AGEs and their receptors, including receptor for AGEs (RAGE) and soluble receptor for AGEs (sRAGE). The search method initially identified 484 articles; 331 remained after duplicate removal. Thirty-five articles were screened and identified as relevant to the study topic. After critical analysis, 27 articles were included in the final analysis. Vitamin D treatment may possibly be beneficial to reduce AGE levels and to augment sRAGE levels, particularly in vitamin D-deficient situations. Treatment with this vitamin may be effective in reducing RAGE expression in some disease conditions, but might be even harmful under normal conditions. The inhibitory or stimulatory effects of vitamin D on AGE receptors are mediated by various signaling pathways, MAPK/NF-κB, ADAM10/MMP9 and AT1R. In populations with chronic diseases and concomitant hypovitaminosis D, vitamin D supplementation can be used as a strategy to ameliorate AGE-mediated complications by modifying the AGE-RAGE and sRAGE systems.

Advanced glycation end products (AGEs), protein aggregation and their cross talk: new insight in tumorigenesis

Protein glycation and protein aggregation are two distinct phenomena being observed in cancer cells as factors promoting cancer cell viability. Protein aggregation is an abnormal interaction between proteins caused as a result of structural changes in them after any mutation or environmental assault. Protein aggregation is usually associated with neurodegenerative diseases like Alzheimer's and Parkinson's, but of late, research findings have shown its association with the development of different cancers like lung, breast and ovarian cancer. On the contrary, protein glycation is a cascade of irreversible nonenzymatic reaction of reducing sugar with the amino group of the protein resulting in the modification of protein structure and formation of advanced glycation end products (AGEs). These AGEs are reported to obstruct the normal function of proteins. Lately, it has been reported that protein aggregation occurs as a result of AGEs. This aggregation of protein promotes the transformation of healthy cells to neoplasia leading to tumorigenesis. In this review, we underline the current knowledge of protein aggregation and glycation along with the cross talk between the two, which may eventually lead to the development of cancer.

Downregulation of RAGE Inhibits Cell Proliferation and Induces Apoptosis via Regulation of PI3K/AKT Pathway in Cervical Squamous Cell Carcinoma

Aim

The receptor for advanced glycation endproducts (RAGE) expression has been reported to be implicated with cancer development. In this study, the role of RAGE in the regulation of cervical squamous cancer cell proliferation, apoptosis and the mechanism of RAGE involved in the biological behaviors were explored.

Methods

The RAGE expression was overexpressed or downregulated by lentivirus transfection. The effect of RAGE expression on cell proliferation was explored by CCK-8, MTT, and BrdU assay, and the effect of RAGE on tumor development was confirmed by the xenograft mouse model along with the immunohistochemistry stain of proliferating cell nuclear antigen (PCNA). Apoptosis was investigated by flow cytometry and TUNEL assay. Western blotting was performed to investigate the expression of possible proteins, including Bax, Bcl-2, PI3K, p-PI3K, AKT, and p-AKT.

Results

Overexpression of RAGE promoted proliferation of cervical squamous cancer cell and increased PCNA expression. In the meantime, RAGE overexpression inhibited cell apoptosis along with a decrease of Bax/Bcl-2 ratio, and induction of PI3K/AKT activation. The in vivo results showed that overexpression of RAGE enhanced tumor growth. Conversely, knockdown of RAGE exhibited opposed effects on cervical cancer cells and xenograft mouse model. Furthermore, RAGE inhibitor FPS-ZM1 effectively inhibited SiHa cell viability and PCNA expression, and increased cell apoptosis and Bax/Bcl-2 ratio. Moreover, PI3K inhibitor LY294002 effectively inhibited activation of PI3K and AKT, and further repressed RAGE overexpression-induced cell proliferation and apoptosis inhibition.

Conclusion

RAGE promotes the growth ability of cervical squamous cell carcinoma by inducing PCNA expression and inhibiting cell apoptosis via inactivation of the PI3K/AKT pathway.

Therapeutic Potential of Pigment Epithelium-derived Factor in Cancer

Pigment epithelium-derived factor (PEDF) is one of the serine protease inhibitors with multifunctional properties, which is produced by various types of organs and tissues. There is an accumulating body of evidence that PEDF plays an important role in the maintenance of tissue homeostasis. Indeed, PEDF not only works as an endogenous inhibitor of angiogenesis, but also suppresses oxidative stress, inflammatory and thrombotic reactions in cell culture systems, animal models, and humans. Furthermore, we, along with others, have found that PEDF inhibits proliferation of, and induces apoptotic cell death in, numerous kinds of tumors. In addition, circulating as well as tumor expression levels of PEDF have been inversely associated with tumor growth and metastasis. These observations suggest that supplementation of PEDF proteins and/or enhancement of endogenous PEDF expression could be a novel therapeutic strategy for the treatment of cancer. Therefore, in this paper, we review the effects of PEDF on diverse types of cancer, and discuss its therapeutic perspectives.

Pathological Role of Advanced Glycation End Products (AGEs) and their Receptor Axis in Atrial Fibrillation

Accumulating evidence has shown that the incidence of atrial fibrillation (AF) is higher in patients with diabetes, especially those with poor glycemic control or long disease duration. Nonenzymatic glycation of amino acids of proteins, lipids, and nucleic acids has progressed under normal aging process and/or diabetic condition, which could lead to the formation and accumulation of advanced glycation end products (AGEs). AGEs not only alter the tertiary structure and physiological function of macromolecules, but also evoke inflammatory and fibrotic reactions through the interaction of cell surface receptor for AGEs (RAGE), thereby being involved in aging-related disorders. In this paper, we briefly review the association of chronic hyperglycemia and type 1 diabetes with the risk of AF and then discuss the pathological role of AGE-RAGE axis in AF and its thromboembolic complications.

Long-Term Local Injection of RAGE-Aptamer Suppresses the Growth of Malignant Melanoma in Nude Mice

Accumulating evidence has suggested the pathological role of advanced glycation end products (AGEs) and their receptor RAGE axis in aging-associated disorders, including cancers. In this study, we examined the effects of local injection of RAGE-aptamer adjacent to the tumor on G361 melanoma growth in nude mice. We further investigated the effects of RAGE-aptamer on oxidative stress generation, RAGE, vascular endothelial growth factor (VEGF), and monocyte chemoattractant protein-1 (MCP-1) gene expression in N^ε-(carboxymethyl)lysine (CML)-exposed G361 melanoma cells in vitro. Local injection of RAGE-aptamer adjacent to the tumor dramatically decreased the growth of G361 melanoma in nude mice, which was associated with reduced expression of CML, RAGE, nitrotyrosine, VEGF, CD31, and von Willebrand factor, markers of endothelial cells in G361 tumors. Furthermore, RAGE-aptamer inhibited the binding of CML to V-domain of RAGE and blocked the CML-induced increases in oxidative stress generation, RAGE, VEGF, and MCP-1 mRNA levels in G361 melanoma cells. Our present findings suggest that long-term local injection of RAGE-aptamer adjacent to the tumor could inhibit melanoma growth in nude mice partly by suppressing tumor angiogenesis via blockade of the CML-RAGE interaction. Local injection of RAGE-aptamer may be a feasible therapeutic tool for the treatment of malignant melanoma.

Role of Advanced Glycation Endproduct (AGE)-Receptor for Advanced Glycation Endproduct (RAGE) Axis in Cardiovascular Disease and Its Therapeutic Intervention

Despite the early loss of glycemic differences between the original intensive therapy group and conventional treatment in the DCCT/EDIC and UKPDS 80 trials, a continued reduction in microvascular risk and risk reductions for emergency myocardial infarction and all-cause death were observed 10-30 years after the end of these trials. These observations demonstrated that so-called "metabolic memory" could cause chronic abnormalities in diabetic vessels that are not easily reversed, even by subsequent improvement in blood glucose levels, thus suggesting a long-term beneficial influence of early metabolic control; that is, legacy effects on the risk of vascular complications and death in patients with both type 1 and type 2 diabetes. Formation and accumulation of advanced glycation endproducts (AGEs) are known to progress at an accelerated rate under diabetes. Furthermore, AGEs are hardly degraded and remain for a long time in diabetic vessels even after glycemic control is improved. Therefore, AGEs could explain why former cumulative diabetic exposure could contribute to current progression of vascular complications in diabetes. Here, the clinical utility of measurement of serum and tissue accumulation levels of AGEs for evaluating the prevalence and severity of numerous types of cardiovascular disease is reviewed and novel therapeutic strategies that could target the AGE-RAGE axis in CVD are discussed.

The receptor for advanced glycation end-products (RAGE) is an important pattern recognition receptor (PRR) for inflammaging

The receptor for advanced glycation end-products (RAGE) was initially characterized and named for its ability to bind to advanced glycation end-products (AGEs) that form upon the irreversible and non-enzymatic interaction between nucleophiles, such as lysine, and carbonyl compounds, such as reducing sugars. The concentrations of AGEs are known to increase in conditions such as diabetes, as well as during ageing. However, it is now widely accepted that RAGE binds with numerous ligands, many of which can be defined as pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs). The interaction between RAGE and its ligands mainly results in a pro-inflammatory response, and can lead to stress events often favouring mitochondrial dysfunction or cellular senescence. Thus, RAGE should be considered as a pattern recognition receptor (PRR), similar to those that regulate innate immunity. Innate immunity itself plays a central role in inflammaging, the chronic low-grade and sterile inflammation that increases with age and is a potentially important contributory factor in ageing. Consequently, and in addition to the age-related accumulation of PAMPs and DAMPs and increases in pro-inflammatory cytokines from senescent cells and damaged cells, PRRs are therefore important in inflammaging. We suggest here that, through its interconnection with immunity, senescence, mitochondrial dysfunction and inflammasome activation, RAGE is a key contributor to inflammaging and that the pro-longevity effects seen upon blocking RAGE, or upon its deletion, are thus the result of reduced inflammaging.

Inhibition of RAGE Axis Signaling: A Pharmacological Challenge

The Receptor for Advanced Glycation End Products (RAGE) is an important cell surface receptor, which belongs to the IgG super family and is now considered as a pattern recognition receptor. Because of its relevance in many human clinical settings, it is now pursued as a very attractive therapeutic target. However, particular features of this receptor such as a wide repertoire of ligands with different binding domains, the existence of many RAGE variants as well as the presence of cytoplasmatic adaptors leading a diverse signaling, are important limitations in the search for successful pharmacological approaches to inhibit RAGE signaling. Therefore, the present review aimed to display the most promising approaches to inhibit RAGE signaling, and provide an up to date review of progress in this area.

Role of advanced glycation end products in mobility and considerations in possible dietary and nutritional intervention strategies

Advanced glycation end products (AGEs), a group of compounds that are formed by non-enzymatic reactions between carbonyl groups of reducing sugars and free amino groups of proteins, lipids or nucleic acids, can be obtained exogenously from diet or formed endogenously within the body. AGEs accumulate intracellularly and extracellularly in all tissues and body fluids and can cross-link with other proteins and thus affect their normal functions. Furthermore, AGEs can interact with specific cell surface receptors and hence alter cell intracellular signaling, gene expression, the production of reactive oxygen species and the activation of several inflammatory pathways. High levels of AGEs in diet as well as in tissues and the circulation are pathogenic to a wide range of diseases. With respect to mobility, AGEs accumulate in bones, joints and skeletal muscles, playing important roles in the development of osteoporosis, osteoarthritis, and sarcopenia with aging. This report covered the related pathological mechanisms and the potential pharmaceutical and dietary intervention strategies in reducing systemic AGEs. More prospective studies are needed to determine whether elevated serum AGEs and/or skin autofluorescence predict a decline in measures of mobility. In addition, human intervention studies are required to investigate the beneficial effects of exogenous AGEs inhibitors on mobility outcomes.

The effects of a maternal advanced glycation end product-rich diet on somatic features, reflex ontogeny and metabolic parameters of offspring mice

Maternal exposure to a Western type diet during pregnancy might predispose the offspring to manifestation of metabolic and behavioral disturbances in later life. The Western type diet contains large amounts of advanced glycation end products (AGEs). In humans and experimental rodents, the intake of an AGE-rich diet (AGE-RD) negatively affected glucose homeostasis, and initiated the production of reactive oxygen species. Rats consuming the AGE-RD presented changes in behavior. It remains unclear whether maternal intake of the AGE-RD might affect developmental plasticity in offspring. We examined early somatic (weight, incisor eruption, ear unfolding, and eye opening) and neuromotor development, oxidative status, insulin sensitivity (HOMA index) and locomotor activity assessed in PhenoTyper cages in the offspring of mice fed during pregnancy with either the AGE-RD (25% bread crusts/75% control chow) or control chow. Until weaning, the somatic development of offspring did not differ between the two dietary groups. The AGE-RD offspring manifested physiological reflexes (auditory startle, eye lid, ear twitch and righting reflexes) earlier. As young adults, the male offspring of the AGE-RD dams were heavier and less insulin sensitive compared with their control counterparts. The AGE-RD offspring showed higher locomotor activity during the active phase. Our data indicate that the maternal AGE-RD during pregnancy might accelerate the maturation of reflexes in offspring, predispose the male progeny to weight gain and affect their glucose homeostasis. These effects manifest without the direct consumption of the AGE-RD by offspring. Further work is needed to determine the mechanisms by which the maternal AGE-RD affects neurobehavioral pathways in offspring, as well as sex differences in adverse metabolic responses.

RAGE-aptamer attenuates deoxycorticosterone acetate/salt-induced renal injury in mice

The mineralocorticoid receptor (MR) and its downstream signaling play an important role in hypertensive renal injury. The interaction of advanced glycation end products (AGE) with their receptor (RAGE) is involved in the progression of renal disease. However, the pathological crosstalk between AGE–RAGE axis and MR system in kidney derangement remains unclear. We screened DNA-aptamer directed against RAGE (RAGE-apt) in vitro and examined its effects on renal injury in uninephrectomized deoxycorticosterone acetate (DOCA)/salt-induced hypertensive mice. RAGE, GTP-bound Rac-1 (Rac1), and MR were co-localized in the podocytes of DOCA mice. The deletion of RAGE gene significantly inhibited mesangial matrix expansion and tubulointerstitial fibrosis in DOCA mice, which was associated with the reduction of glomerular oxidative stress, MR, Rac1, and urinary albumin excretion (UAE) levels. RAGE-apt attenuated the increase in carboxymethyllysine (CML), RAGE, nitrotyrosine, Rac1, and MR levels in the kidneys and reduced UAE in DOCA mice. Aldosterone (Aldo) increased nitrotyrosine, CML, and RAGE gene expression in murine podocytes, whereas CML stimulated MR and Rac1 levels, which were blocked by RAGE-apt. The present study indicates the crosstalk between the AGE–RAGE axis and Aldo–MR system, suggesting that RAGE-apt may be a novel therapeutic tool for the treatment of MR-associated renal diseases.

RAGE may act as a tumour suppressor to regulate lung cancer development

Although the correlation of the RAGE rs2070600 polymorphism and cancer risk has been confirmed, detailed studies with functional and experimental evaluations are lacking. In this study, we first aimed to examine whether this polymorphism is associated with cancer risk based on the latest published data, and consistent with previous meta-analyses, a significant association between the rs2070600 polymorphism and cancer risk was observed (A versus G: OR = 1.25; 95% CI = 1.12-1.40). In additional stratified analyses based on cancer type, rs2070600 was significantly associated with an increased risk of lung cancer (A versus G: OR = 1.20; 95% CI = 1.09-1.33). Moreover, TCGA database showed that the expression level of RAGE was significantly lower in lung cancer tumour tissues than in adjacent non-tumour tissues, which was validated in the GEO database. Additionally, eQTL analysis indicated that the rs2070600 polymorphism may modify the expression level of RAGE in lung squamous cell carcinoma tissues (P = 0.09). Finally, we performed functional experiments in lung cancer cells and preliminarily demonstrated that RAGE may act as a tumour suppressor in lung cancer development. These findings provide evidence that the variant A allele of rs2070600 may decrease the expression of the tumour suppressor gene RAGE, thereby increasing lung cancer risk.

Association of advanced glycation end products, evaluated by skin autofluorescence, with lifestyle habits in a general Japanese population

Objective

Accumulation of advanced glycation end products (AGEs) occurs during normal aging but markedly accelerates in people with diabetes. AGEs may play a role in various age-related disorders. Several studies have demonstrated that skin autofluorescence (SAF) reflects accumulated tissue levels of AGEs. However, very few studies have investigated SAF in the general population. The purpose of the present study was to more thoroughly evaluate the potential association among SAF, chronological age, and lifestyle habits in the general population.

Methods

A large cross-sectional survey of 10,946 Japanese volunteers aged 20 to 79 years was conducted. Volunteers completed a self-administered questionnaire and underwent SAF measurement on their dominant forearms. The associations of SAF with age and lifestyle habits were analyzed using a multiple stepwise regression analysis.

Results

Age was independently correlated with SAF. Lifestyle habits such as physical activity, nonsmoking, adequate sleep, low mental stress level, eating breakfast, and abstaining from sugary food were each independently associated with lower SAF.

Conclusions

SAF was associated with age and healthy lifestyle habits in this general Japanese population. The present study suggests that SAF measurement is a convenient tool for evaluating habitual lifestyle behaviors and may have potential for preventative health education.

RAGE-aptamer Attenuates the Growth and Liver Metastasis of Malignant Melanoma in Nude Mice

Epidemiological studies have suggested the link between cumulative diabetic exposure and cancer. Interaction of advanced glycation end products (AGEs) with their receptor (RAGE) may contribute to the phenomenon. We examined here the effects of DNA aptamer raised against RAGE (RAGE-aptamer) on growth and liver metastasis of G361 melanoma in nude mice. Malignant melanoma cells were intradermally injected into the upper flank region of nude mice, which received continuous administration of RAGE-aptamer (38.4 pmol/day/g body weight) or vehicle intraperitoneally by an osmotic pump up to 42 days. RAGE-aptamer significantly reduced levels of 8-hydroxy-2'-deoxy-guanosine, AGEs, RAGE, proliferating nuclear antigen, cyclin D1, vascular endothelial growth factor (VEGF), monocyte chemoattractant protein-1 (MCP-1), and CD31 and Mac-3, respective markers of endothelial cells and macrophages in tumors of nude mice and suppressed the proliferation and liver metastasis of malignant melanoma. Furthermore, RAGE-aptamer attenuated the AGE-induced oxidative stress generation, proliferation, and VEGF and MCP-1 gene expression in both G361 melanoma cells and endothelial cells. The present findings suggest that RAGE-aptamer could attenuate melanoma growth and liver metastasis in nude mice by suppressing the tumor angiogenesis and macrophage infiltration via inhibition of the AGE-RAGE system. RAGE-aptamer may be a novel therapeutic tool for the treatment of malignant melanoma.

Glucose-derived AGEs enhance human gastric cancer metastasis through RAGE/ERK/Sp1/MMP2 cascade

Advanced glycation end products (AGEs) have been reported to take part in many cancer processes. Whether AGEs contribute to gastric cancer (GC) course and the underlying mechanism are still unclear. Here, glucose-derived AGEs are detected to be accumulated in tumor tissues and blood of patients with GC. As the receptor for AGEs, RAGE is highly expressed in cancer tissues, and closely associated with the depth of cancer invasion, lymph node metastasis and TNM stage. Both in vivo and in vitro treatment of AGEs accelerate the tumor invasion and metastasis, with upregualtion of RAGE, Specificity Protein 1 (Sp1), and MMP2 protein expression, as well as enhancement of MMP2 activity. Either RAGE-blocking antibody or Sp1-knockdown can partially block the AGEs-induced effects. Moreover, AGEs increased the phosphorylation of ERK, and reducing the phosphorylation level of ERK by MEK1/2 inhibitor decreased the expression of Sp1. These results indicate that accumulation of glucose-derived AGEs may act as one of potential risk factors for GC progression and promote the invasion and metastasis of gastric cancer partially through the activation of RAGE/ERK/Sp1/MMP2 pathway.

Ousting RAGE in melanoma: A viable therapeutic target?

Melanoma remains an important health concern, given the steady increase in incidence and acquisition of resistance to systemic therapies. The receptor for advanced glycation end products (RAGE) initially identified for its binding to advanced glycation end products was subsequently acknowledged as a pattern recognition receptor given its ability to recognize similar structural elements within numerous ligands. Recent studies have elucidated a plausible role of RAGE in melanoma progression through modulation of inflammatory, proliferative and invasive cellular responses. Several of its ligands including the S100 proteins and HMGB1 are being investigated for their involvement in melanoma metastasis and as potential biomarkers of the disease. Targeting RAGE signaling represents a viable therapeutic strategy which remains underexplored in cutaneous malignancies. Here we have summarized current knowledge on the functionality of RAGE with special focus on specific ligands enumerated in various in vitro and in vivo melanoma models.

Commentary on Some Recent Theses Relevant to Combating Aging: August 2017

Theses reviewed in this issue include "Engineering Cellular Input-Output for the Robust Control of Mammalian Cell-Based Therapies"; "Enzyme-Instructed Self-Assembly (EISA) Selectively Targets Cancer Cells"; "Exploration of helminth-derived immunoregulatory molecules as options for therapeutic intervention in allograft rejection and autoimmune disease"; "Expression of the Medial HOXA genes is indispensible for self-renewal in human hematopoietic stem cells"; "Gamma frequency entrainment attenuates amyloid load and modifies microglia"; and "Heterogeneous Distribution of Microvascular Blood Flow Contributes to Impaired Skeletal Muscle Oxygenation in Diabetes".

Advanced glycation endproducts (AGEs) in saliva of patients with multiple myeloma - a pilot study

Multiple myeloma (MM) is a hematological cancer with underlying causes associated with increased oxidative stress. Through signaling of their receptor RAGE, advanced glycation endproducts (AGEs) are known to increase oxidative stress associated with malignant transformation. In the present study, we have demonstrated that the levels of these compounds are increased in the saliva of myeloma patients with bone lesions. This data may provide a potential marker for bone lesions in MM and a potential target for the treatment of myeloma by blocking the AGEs or their receptor.

Hypoxia driven glycation: Mechanisms and therapeutic opportunities

Tumor masses are deprived of oxygen and characterized by enhanced glucose uptake followed by glycolysis. Elevated glucose levels induce non-enzymatic glycosylation or glycation of proteins which leads to accumulation of advanced glycation end products (AGE). These AGE molecules bind to their respective receptors called the receptor for advanced glycation end products (RAGE) and initiate several aberrant signaling pathways leading to onset of diseases such as diabetes, Alzheimer's, atherosclerosis, heart failure and cancer. The role of AGE in cancer progression is being extensively studied in recent years. As cancer cells are hypoxic in nature and adapted to glycolysis, which induces glycation, its effects need to be understood in greater detail. Since AGE-RAGE signaling is involved in cancer progression, inhibition of AGE-RAGE interaction could be a potential therapeutic target. The purpose of this review is to highlight the role of AGE-RAGE interaction in hypoxic cancer cells.

Glycation and cardiovascular disease in diabetes: A perspective on the concept of metabolic memory

Epidemiological studies have suggested that cumulative diabetic exposure, namely prolonged exposure to chronic hyperglycemia, contributes to the increased risk of cardiovascular disease (CVD) in diabetes. The formation and accumulation of advanced glycation end-products (AGEs) have been known to progress under hyperglycemic conditions. Because AGEs-modified collagens are hardly degraded and remain in diabetic vessels, kidneys and the heart for a long time, even after glycemic control has been achieved, AGEs could become a marker reflecting cumulative diabetic exposure. Furthermore, there is a growing body of evidence that an interaction between AGEs and the receptor for AGEs (RAGE) plays a role in the pathogenesis of CVD. In addition, AGEs induce the expression of RAGE, thus leading to sustained activation of the AGEs-RAGE axis in diabetes. Herein we review the pathological role of the AGEs-RAGE axis in CVD, focusing particularly on the phenomenon of metabolic memory, and discuss the potential clinical usefulness of measuring circulating and tissue levels of AGEs accumulation to evaluate diabetic macrovascular complications.

Plasma Levels of Pentosidine, Carboxymethyl-Lysine, Soluble Receptor for Advanced Glycation End Products, and Metabolic Syndrome: The Metformin Effect

Metabolic syndrome (MetS) is considered one of the most important public health problems. Several and controversial studies showed that the role of advanced glycation end products (AGEs) and their receptor in the development of metabolic syndrome and therapeutic pathways is still unsolved. We have investigated whether plasma pentosidine, carboxymethyl-lysine (CML), and soluble receptor for advanced glycation end products (sRAGE) levels were increased in patients with MetS and the effect of metformin in plasma levels of pentosidine, CML, and sRAGE. 80 control subjects and 86 patients were included in this study. Pentosidine, CML, and sRAGE were measured in plasma by enzyme-linked immunosorbent assay (ELISA). Plasma pentosidine, CML, and sRAGE levels were significantly increased in patients compared to control subjects (P < 0.001, P < 0.001, and P = 0.014, resp.). Plasma levels of pentosidine were significantly decreased in patients who received metformin compared to untreated patients (P = 0.01). However, there was no significant difference between patients treated with metformin and untreated patients in plasma CML levels. Plasma levels of sRAGE were significantly increased in patients who received metformin and ACE inhibitors (P < 0.001 and P = 0.002, resp.). However, in a multiple stepwise regression analysis, pentosidine, sRAGE, and drugs treatments were not independently associated. Patients with metabolic syndrome showed increased levels of AGEs such as pentosidine and CML. Metformin treatment showed a decreased level of pentosidine but not of CML. Therapeutic pathways of AGEs development should be taken into account and further experimental and in vitro studies merit for advanced research.

Protective role of sulphoraphane against vascular complications in diabetes

Context Diabetes is a global health challenge. Although large prospective clinical trials have shown that intensive control of blood glucose or blood pressure reduces the risk for development and progression of vascular complications in diabetes, a substantial number of diabetic patients still experience renal failure and cardiovascular events, which could account for disabilities and high mortality rate in these subjects. Objective Sulphoraphane is a naturally occurring isothiocyanate found in widely consumed cruciferous vegetables, such as broccoli, cabbage and Brussels sprouts, and an inducer of phase II antioxidant and detoxification enzymes with anticancer properties. We reviewed here the protective role of sulphoraphane against diabetic vascular complications. Methods In this review, literature searches were undertaken in Medline and in CrossRef. Non-English language articles were excluded. Keywords [sulphoraphane and (diabetes, diabetic nephropathy, diabetic retinopathy, diabetic neuropathy, diabetic complications, vascular, cardiomyocytes, heart or glycation)] have been used to select the articles. Results There is accumulating evidence that sulphoraphane exerts beneficial effects on vascular damage in both cell culture and diabetic animal models via antioxidative properties. Furthermore, we have recently found that sulphoraphane inhibits in vitro formation of advanced glycation end products (AGEs), suppresses the AGE-induced inflammatory reactions in rat aorta by reducing receptor for AGEs (RAGE) expression and decreases serum levels of AGEs in humans. Conclusion These findings suggest that blockade of oxidative stress and/or the AGE-RAGE axis by sulphoraphane may be a novel therapeutic strategy for preventing vascular complications in diabetes.

Increased Expression of the Receptor for Advanced Glycation End-Products (RAGE) Is Associated with Advanced Breast Cancer Stage

BACKGROUND

The receptor for advanced glycation end-products (RAGE) is a multiligand transmembrane receptor that is overexpressed in various pathological conditions including cancers. However, the expression pattern of RAGE in breast cancer tumors is still not completely clear.

METHODS

In this study, we investigated the expression levels of RAGE in 25 fresh-frozen breast cancer samples and corresponding noncancerous tissue samples collected from breast cancer patients, by real-time polymerase chain reaction (PCR). Additionally, we performed immunohistochemistry on breast cancer specimens.

RESULTS

The results indicate a high expression of the RAGE-encoding gene in the cancerous tissues. RAGE expression at the mRNA and protein levels was statistically significantly up-regulated in advanced-stage and triple-negative breast tumors and node-positive tissues compared with other tissues (p < 0.001). A significant association between RAGE expression and tumor size was observed (p = 0.029).

CONCLUSIONS

Overexpression of RAGE in advanced-stage tumors may be a useful biomarker for diagnosis and the prediction of breast cancer progression.

DNA-aptamers raised against AGEs as a blocker of various aging-related disorders

A non-enzymatic reaction between sugars or aldehydes and the amino groups of proteins, lipids and nucleic acids contributes to the aging of macromolecules, which could impair their structural integrity and function. This process begins with the conversion of reversible Schiff base adducts, and then to more stable, covalently-bound Amadori rearrangement products. Over a course of days to weeks, these early glycation products undergo further reactions, such as rearrangements and dehydration to become irreversibly crossed-linked, fluorescent protein derivatives termed advanced glycation end products (AGEs). The formation and accumulation of AGEs have been known to progress in a physiological aging process and at an accelerated rate under hyperglycemic, inflammatory and oxidative stress conditions. There is a growing body of evidence that AGEs and their receptor RAGE interaction play a role in the pathogenesis of various devastating disorders, including cardiovascular disease, Alzheimer's disease, insulin resistance, osteoporosis and cancer growth and metastasis. Furthermore, diet has been recently recognized as a major environmental source of AGEs that could also elicit pro-inflammatory reactions, thereby being involved in organ damage in vivo. Therefore, inhibition of AGE formation and/or blockade of the interaction of AGEs with RAGE may be a novel therapeutic target for aging-related disorders. This article discusses a potential utility of DNA-aptamers raised against AGEs for preventing aging and/or diabetes-associated organ damage, especially focusing on diabetic microvascular complications, vascular remodeling, metabolic derangements, and melanoma growth and expansion in animal models.