RAGE genetic polymorphisms are associated with risk, chemotherapy response and prognosis in patients with advanced NSCLC

Contributions of the receptor for advanced glycation end products axis activation in gastric cancer

Compelling shreds of evidence derived from both clinical and experimental research have demonstrated the crucial contribution of receptor for advanced glycation end products (RAGE) axis activation in the development of neoplasms, including gastric cancer (GC). This new actor in tumor biology plays an important role in the onset of a crucial and long-lasting inflammatory milieu, not only by supporting phenotypic changes favoring growth and dissemination of tumor cells, but also by functioning as a pattern-recognition receptor in the inflammatory response to Helicobacter pylori infection. In the present review, we aim to highlight how the overexpression and activation of the RAGE axis contributes to the proliferation and survival of GC cells as and their acquisition of more invasive phenotypes that promote dissemination and metastasis. Finally, the contribution of some single nucleotide polymorphisms in the RAGE gene as susceptibility or poor prognosis factors is also discussed.

The impact of receptor of advanced glycation end-products polymorphisms on prostate cancer progression and clinicopathological characteristics

The receptor for advanced glycation end products (RAGE) overexpression was suggested to be associated with prostate cancer development and poor prognosis. In this study, we focused on the correlations between the clinicopathological characteristics and susceptibility of prostate cancer and RAGE single-nucleotide polymorphisms (SNPs). In 579 prostate cancer patients, the RAGE SNPs rs1800625, rs1800624, rs2070600 and rs184003 in patients with or without grade group upgrade were analysed with real-time polymerase chain reaction. The results demonstrated that the prostate cancer patients who carried the RAGE SNPs rs2070600 'GA' genotypic variants were significantly associated with lower risk to develop grade group upgrade. Moreover, patients with the RAGE rs1800625 'TC + CC' genotypic variants were associated with higher risk of perineural invasion. In 343 prostate cancer patients who carried the RAGE rs1800625 'TC + CC' genotype without grade group upgrade were correlated with higher risk of biochemical recurrence and perineural invasion. In the analysis of TCGA database, significant differences of the RAGE mRNA level were found between the normal controls and prostate cancer patients (p < 0.0001), and the pathologic stage N1 and N0 patients (p = 0.0027). The prostate cancer patients with high RAGE expression were associated with lower overall survival rate (p = 0.025). In conclusion, our results have revealed that the RAGE SNPs rs2070600 and rs1800625 were associated with the grade group upgrade of prostate cancer and clinical status. The RAGE polymorphisms may provide as a pivotal predictor to evaluate prostate cancer disease progression and prognosis.

Receptor for Advanced Glycation End Products (RAGE) and Its Polymorphic Variants as Predictive Diagnostic and Prognostic Markers of NSCLCs: a Perspective

PURPOSE OF REVIEW

Non-small cell lung cancers (NSCLCs) account for ~ 85% of all lung cancers, and 5-year survival in Europe and the USA is ~ 13-17%. In this review, we focus on the significance of Receptor for Advanced Glycation End products (RAGE) as a diagnostic or post-therapeutic prognostic marker for various forms of NSCLCs.

RECENT FINDINGS

The lungs have the highest levels of basal RAGE expression in mammals. The physiologic RAGE in lungs may be involved in adhesion and spreading of AT-1 cells and maintenance of pulmonary homeostasis. However, high level expression of RAGE complicates various diseases including acute lung injury. In NSCLCs, while a number of studies report decreased RAGE expression, inferring a protective role, others suggest that RAGE expression may contribute to NSCLC pathogenesis. Genetic polymorphisms of RAGE are reportedly associated with NSCLC development and complications. RAGE and its polymorphic variants may be useful diagnostic or post-therapeutic prognostic markers of NSCLCs.

The Gly82Ser mutation in AGER contributes to pathogenesis of pulmonary fibrosis in combined pulmonary fibrosis and emphysema (CPFE) in Japanese patients

The dominant pathogenesis underlying the combined pulmonary fibrosis and emphysema (CPFE) remains unresolved. The receptor for advanced glycation end-products (RAGE) is highly expressed in lung tissues and interacts with distinct multiple ligands, implicating it in certain lung diseases. To elucidate the pathogenesis of CPFE, we genotyped three single nucleotide polymorphisms (SNPs: rs2070600, rs1800625, and rs2853807) of the gene encoding RAGE (AGER) in 111 CPFE patients and 337 chronic obstructive pulmonary disease (COPD) patients of Japanese by using StepOne Real-Time PCR System for SNP genotyping assay. Serum levels of soluble RAGE (sRAGE) were measured by ELISA. We found that the allele frequency of rs2070600 was significantly different between the two groups [corrected P (Pc) = 0.015]. In addition, the minor allele was associated with CPFE patients relative to COPD patients in a dominant effect model (Odds Ratio = 1.93; Pc = 0.018). Moreover, the serum sRAGE level was significantly lower in the CPFE group than the COPD group (P = 0.014). The rs2070600 minor allele was significantly associated with reduced sRAGE level in CPFE patients and independently affected sRAGE level reduction in this group (P = 0.020). We concluded that the AGER rs2070600 minor allele (Gly82Ser mutation) is associated with the pathogenesis of pulmonary fibrosis in CPFE in Japanese patients.

Association of RAGE rs1800625 Polymorphism and Cancer Risk: A Meta-Analysis of 18 Case-Control Studies

Background

Accumulating evidence suggests that the rs1800625 polymorphism in RAGE promoter region might be associated with cancer risk; however, data from different studies show conflicting results. Here, a meta-analysis was conducted to evaluate the associations between RAGE rs1800625 polymorphism and cancer risk.

Material/Methods

We searched Embase (Excerpt Medica Database), PubMed, and CNKI (Chinese National Knowledge Infrastructure) databases until March 15, 2019 to identify potential studies for the meta-analysis.

Results

Eighteen eligible studies were included in the current meta-analysis, representing 6246 cases and 6819 controls. Pooled analysis showed positive correlation between the RAGE rs1800625 polymorphism and susceptibility of cancer in recessive genetic model [CC versus TC+TT: odds ratio (OR)=1.397, 95% confidence interval (CI): 1.031–1.894, P=0.031]. Subgroup analysis revealed this association in the Asian, but not Caucasian population, and this correlation was not detected in either breast or lung cancer. Sensitivity analysis indicated unstable results, which should be interpreted with caution. No publication bias was observed.

Conclusions

In conclusion, the RAGE rs1800625 polymorphism was associated with increased overall cancer risk in Asians in recessive genetic model. However, large-scale and well-designed studies in different populations and diverse cancer types are needed for a precise conclusion.

Identification of differentially expressed genes and enriched pathways in lung cancer using bioinformatics analysis

Lung cancer is the leading cause of cancer‑associated mortality worldwide. The aim of the present study was to identify the differentially expressed genes (DEGs) and enriched pathways in lung cancer by bioinformatics analysis, and to provide potential targets for diagnosis and treatment. Valid microarray data of 31 pairs of lung cancer tissues and matched normal samples (GSE19804) were obtained from the Gene Expression Omnibus database. Significance analysis of the gene expression profile was used to identify DEGs between cancer tissues and normal tissues, and a total of 1,970 DEGs, which were significantly enriched in biological processes, were screened. Through the Gene Ontology function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, 77 KEGG pathways associated with lung cancer were identified, among which the Toll‑like receptor pathway was observed to be important. Protein‑protein interaction network analysis extracted 1,770 nodes and 10,667 edges, and identified 10 genes with key roles in lung cancer with highest degrees, hub centrality and betweenness. Additionally, the module analysis of protein‑protein interactions revealed that 'chemokine signaling pathway', 'cell cycle' and 'pathways in cancer' had a close association with lung cancer. In conclusion, the identified DEGs, particularly the hub genes, strengthen the understanding of the development and progression of lung cancer, and certain genes (including advanced glycosylation end‑product specific receptor and epidermal growth factor receptor) may be used as candidate target molecules to diagnose, monitor and treat lung cancer.

A multicenter matched case-control analysis on seven polymorphisms from HMGB1 and RAGE genes in predicting hepatocellular carcinoma risk

Based on 540 hepatocellular carcinoma patients and 540 age- and gender-matched controls, we tested the hypothesis that high mobility group protein box1 (HMGB1) and the receptor for advanced glycation end products (RAGE) genes are two potential candidate susceptibility genes for hepatocellular carcinoma in a multicenter hospital-based case-control analysis. The genotypes of seven widely-studied polymorphisms were determined, and their distributions respected the Hardy-Weinberg equilibrium. The mutant alleles of two polymorphisms, rs1045411 in HMGB1 gene and rs2070600 in RAGE gene, had significantly higher frequencies in patients than in controls (P < 0.001), with the power to detect this significance of being over 99.9%. Moreover, the above two polymorphisms increased the risk of developing hepatocellular carcinoma significantly, particularly for rs2070600 under the additive (odds ratio [OR] = 1.77; 95% confidence interval [CI]: 1.34-2.32; P < 0.001) and dominant (OR = 1.75; 95% CI: 1.23-2.50; P = 0.002) models after adjusting for body mass index, smoking and drinking. Haplotype analysis showed that the T-C-T haplotype (rs1045411-rs2249825-rs1415125) in HMGB1 gene was associated with a 2.47-fold (95% CI: 1.41-4.34; P = 0.002) increased risk of hepatocellular carcinoma compared with the commonest C-C-T haplotype after adjustment. In RAGE gene, the T-T-A-G (rs1800625-rs1800624-rs2070600-rs184003) (adjusted OR; 95% CI; P: 1.75; 1.02-3.03; 0.045) and T-T-A-T (adjusted OR; 95% CI; P: 1.95; 1.01-3.76; 0.048) haplotypes were associated with a marginally increased risk of hepatocellular carcinoma compared with the commonest T-T-G-G haplotype. In summary, we identified two risk-associated polymorphisms (rs1045411 and rs2070600), and more importantly a joint impact of seven polymorphisms from the HMGB1/RAGE axis in susceptibility to hepatocellular carcinoma.

Long non-coding RNA AGER-1 functionally upregulates the innate immunity gene AGER and approximates its anti-tumor effect in lung cancer

Little is known about long non-coding RNA (lncRNA) related to innate immunity in lung cancer. The advanced glycosylation end-product specific receptor (AGER) belongs to the immunoglobulin superfamily, and currently, is the only innate immune pattern-recognition receptor whose abnormal expression has been detected in lung cancer. We aimed to explore the lncRNA that is related to AGER and test its effect on lung carcinogenesis. We selected one lncRNA whose chromosome location is in close proximity to AGER namely lnc-AGER-1 (defined as lncAGER). The expression of lncAGER was tested in 276 pairs of lung cancer tissues and adjacent lung normal tissues, and its correlation with lung cancer clinical progress was analyzed. A series of assays were further used to assess the biological function of lncAGER on lung cancer development, tumor immunity and autophagy. LncAGER expression was moderately correlated with AGER expression (r = 0.360, P = 2.15 × 10^-18 ) underlying a mechanism that lncAGER upregulates AGER by competitively binding to miRNA-185. LncAGER was significantly down-regulated in 76.4% of lung cancer tissues compared to adjacent normal tissues due to promoter hypermethylation. Over-expression of the lncRNA resulted in significant decreases in proliferation rate, migration ability, colony formation efficiency of lung cancer cells and tumor growth in nude mice. Notably, lncAGER possibly conduced to enhancement of cytotoxic effect of THP1. Additionally, the lncRNA also promoted cell apoptosis by strengthening autophagy. Taken together, these observations suggest that lncAGER has an inhibitory effect on lung cancer development via AGER, which may serve as a target for lung cancer treatment.

AGER rs2070600 polymorphism elevates neutrophil-lymphocyte ratio and mortality in metastatic lung adenocarcinoma

Background

The receptor for advanced glycation end-product (RAGE) is a multi-ligand receptor involved in inflammation. In the gene encoding RAGE (AGER), there are three well-known polymorphisms; rs2070600, rs1800624, and rs1800625, which potentially increase the risk of lung cancer. Remarkably, AGER rs2070600 polymorphism, which increases ligand-binding affinity, is a potential prognostic factor in non-small cell lung cancer, but the underlying mechanism is unclear. The neutrophil-lymphocyte ratio (NLR) reflects tumor-associated systemic inflammatory conditions; high ratios are associated with poor prognosis in multiple cancers. Additionally, some humoral factors via RAGE-signaling are associated with elevated NLR in cancer patients.

Objectives

Associations of AGER polymorphisms with disease susceptibility, prognosis, and NLR were investigated in Japanese patients with lung adenocarcinoma.

Methods

We included 189 patients with lung adenocarcinoma, 96 of which had distant metastases, and 303 healthy controls. The correlation between AGER polymorphisms (rs2070600, rs1800624, rs1800625) and disease susceptibility and factors elevating the mortality and NLR in patients with metastases were evaluated.

Results

Only the minor allele of rs2070600 was associated with a higher NLR (β = 0.209, p = 0.043) and a poor prognosis (Hazard ratio = 2.06, 95% Confidence interval = 1.09-3.77, p = 0.028) in patients with metastatic disease, independently of background characteristics, including EGFR mutation status. All three polymorphisms were not associated with the risk of lung adenocarcinoma.

Conclusions

The AGER rs2070600 polymorphism was independently associated with systemic inflammation and poor prognosis in patients with metastatic lung adenocarcinoma.

Silencing of advanced glycosylation and glycosylation and product-specific receptor (RAGE) inhibits the metastasis and growth of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) constitutes the main cases of lung cancer and is the world's most common and lethal cancer owing to regional invasion or distant metastasis. Growing morbidity and lethality demonstrates that valid molecular target in management of NSCLC metastasis is still absence. The receptor of advanced glycation end-products (RAGE) has been identified as an oncogenic gene and appears to promote the growth and metastasis of various cancers. Here, we investigated if RAGE targeted by RNA interference (RNAi) might have certain effect on the restraint of the growth of NSCLC and tumor metastasis. Wound healing and Transwell invasion assays indicated that RAGE favored the metastatic capabilities of NSCLC H1975 cells. Besides, soft-agar colony assay revealed that silencing RAGE significantly blocked colony-forming capability of H1975 cells in vitro. Furthermore, we observed that RAGE participated in H1975 cells growth, metastasis and epithelial-mesenchymal transition (EMT) by regulating interdict crux intracellular signaling pathways, including phosphatidylinositol-3 kinase/serine-threonine kinase (PI3K/AKT) and V-Ki-ras2 kirsten rat sarcoma viral oncogene homolog/RAF proto-oncogene serine/threonine-protein kinase (KRAS/RAF-1). In xenograft model, significantly reduction intumor growth and Ki67 expression was demonstrated in nude mice inoculation with RAGE down-regulation H1975 cells. To conclude, our study demonstrated that RAGE played a crucial role in the metastasis and growth of NSCLC by regulating PI3K/AKT and KRAS/RAF-1 signaling pathways, thereby might be a promising therapeutic target for NSCLC.

Effect of RAGE gene polymorphisms and circulating sRAGE levels on susceptibility to gastric cancer: a case-control study

BACKGROUND

To investigate the influence of polymorphisms in the receptor for advanced glycation end products (RAGE) gene and circulating soluble RAGE (sRAGE) levels on susceptibility to gastric cancer, and identify whether these polymorphisms were correlated with serum sRAGE levels.

METHODS

We performed a hospital-based case-control study involving 200 gastric cancer patients and 207 cancer-free controls. Four well-characterized RAGE genetic polymorphisms, namely, rs1800624, rs1800625, rs184003, and rs2070600 were genotyped by PCR-RFLP.

RESULTS

The rs2070600 AG genotype might play a predominant role in the development of gastric cancer (adjusted OR 1.62, 95% CI 1.03-2.58). In contrast, the rs184003 GT genotype represented significantly reduced risk for gastric cancer (adjusted OR 0.62, 95% CI 0.39-0.99). Subgroup analysis demonstrated that rs2070600 AG variant genotype enhanced the gastric cancer risk among nonsmokers (OR 1.71, 95% CI 1.01-2.91), nondrinkers (OR 1.75, 95% CI 1.03-2.97), and patients with tumor stage III (OR 2.00, 95% CI 1.13-3.56). The average sRAGE levels in the gastric cancer patients were significantly decreased compared with those of the healthy controls. Subjects carrying the rs2070600 AG genotype had a decreased ability to produce sRAGE. Subjects carrying the rs184003 T variant allele had an increased ability to sRAGE.

CONCLUSIONS

These findings suggested that the variant genotypes of rs184003 and rs2070600 in the RAGE gene exhibit significant associations with gastric cancer risk and circulating sRAGE levels inverse change simultaneously, leading to a marked causal estimate between lowered sRAGE levels and increased gastric cancer risk.

Lung adenocarcinoma expressing receptor for advanced glycation end-products with primary systemic AL amyloidosis: a case report and literature review

Background

Receptor for advanced glycation end-products (RAGE), a receptor for amyloids, is constitutively expressed in lungs and generally observed to be downregulated in lung cancer tissues. However, increasing levels of RAGE or serum amyloids is associated with poor outcome in lung cancer patients. We report a rare case of primary systemic amyloid light-chain (AL) amyloidosis in biopsy-proven multiple organs with early-stage non-small cell lung cancer (NSCLC) that displayed strong staining for RAGE in the tumour tissue. Interestingly, compared with randomly selected lung cancer biopsy samples, including all representative histological subtypes of NSCLC and small-cell lung cancer, only the NSCLC in the present case showed strong expression for RAGE that can bind amyloids.

Case presentation

A 71-year-old woman was admitted to our hospital for comprehensive investigation of nephrotic syndrome. Computed tomography showed a small nodule in the right upper lung lobe with hilar mediastinal lymph node enlargement. Pathological examination of transbronchial biopsy samples of the nodule yielded a diagnosis of lung adenocarcinoma. Furthermore, the pathological detection of amyloid deposition in biopsy samples of a subcarinal lymph node, gastric and duodenal mucosa, cardiac muscle, and bone marrow led to a diagnosis of primary systemic AL amyloidosis with nephrotic syndrome and cardiomyopathy. In addition, RAGE was detected in lung tumour tissues surrounded by normal lung tissues with amyloid deposition.

Conclusion

The RAGE positivity of the lung cancer cells in this case suggests an interaction between amyloid-containing tissues and RAGE-expressing cancer cells. Lung adenocarcinoma with RAGE expression may be a complication of underlying amyloidosis.

Genetically lowered concentrations of circulating sRAGE might cause an increased risk of cancer: Meta-analysis using Mendelian randomization

Objectives

To undertake a systematic meta-analysis of all variants in the gene encoding receptor for advanced glycation end products (RAGE) to summarize their associations with cancer risk and changes in the levels of circulating soluble RAGE (sRAGE), with the aim of determining possible causality between circulating sRAGE and cancer risk.

Methods

Articles written in English were retrieved from MEDLINE® and EMBASE® databases. Two researchers independently identified eligible articles and extracted the data (analysed using STATA® software version 12.0).

Results

Fifteen articles qualified for inclusion in the meta-analysis of the RAGE–cancer association and three examined the RAGE–sRAGE relationship. The 82Ser/82Ser genotype was significantly associated with overall cancer risk compared with the 82Gly/Gly genotype (odds ratio 1.75, 95% confidence interval [CI] 1.46, 2.10). Carriers of the 82Ser/82Ser genotype had significantly reduced circulating sRAGE concentrations compared with the 82Gly/82Gly genotype. Mendelian randomization analysis demonstrated that a reduction of 100, 200 and 300 pg/ml in circulating sRAGE concentrations was associated with a 1.11-fold (95% CI 1.06, 1.25), 1.24-fold (95% CI 1.11, 1.57) and 1.38-fold (95% CI 1.18, 1.96) increased risk of developing cancer, respectively.

Conclusions

Genetically lowered concentrations of circulating sRAGE might cause an increased risk of cancer.

Prognostic and Predictive Value of DAMPs and DAMP-Associated Processes in Cancer

It is now clear that human neoplasms form, progress, and respond to therapy in the context of an intimate crosstalk with the host immune system. In particular, accumulating evidence demonstrates that the efficacy of most, if not all, chemo- and radiotherapeutic agents commonly employed in the clinic critically depends on the (re)activation of tumor-targeting immune responses. One of the mechanisms whereby conventional chemotherapeutics, targeted anticancer agents, and radiotherapy can provoke a therapeutically relevant, adaptive immune response against malignant cells is commonly known as “immunogenic cell death.” Importantly, dying cancer cells are perceived as immunogenic only when they emit a set of immunostimulatory signals upon the activation of intracellular stress response pathways. The emission of these signals, which are generally referred to as “damage-associated molecular patterns” (DAMPs), may therefore predict whether patients will respond to chemotherapy or not, at least in some settings. Here, we review clinical data indicating that DAMPs and DAMP-associated stress responses might have prognostic or predictive value for cancer patients.

Diminished levels of the soluble form of RAGE are related to poor survival in malignant melanoma

RAGE is a central driver of tumorigenesis by sustaining an inflammatory tumor microenvironment. This study links the soluble forms of RAGE (sRAGE and esRAGE) with clinical outcome of melanoma patients. Moreover, tissue expression of RAGE was analyzed using immunohistochemistry on two independent tissue microarrays (TMA) containing 35 or 257 primary melanomas, and 41 or 22 benign nevi, respectively. Serum concentrations of sRAGE and esRAGE were measured in 229 Stage III-IV patients using ELISA and plasma concentrations of sRAGE were analyzed in an independent second cohort with 173 samples of Stage I-IV patients. In this cohort, three well-described SNPs in the RAGE gene were analyzed. RAGE protein expression was highly upregulated in primary melanomas compared to benign nevi in the two TMA (p < 0.001 and p = 0.005) as well as in sun-exposed melanomas (p = 0.046). sRAGE and esRAGE were identified as prognostic markers for survival as diminished sRAGE (p = 0.034) and esRAGE (p = 0.012) serum levels correlated with poor overall survival (OS). Multivariate Cox regression analysis showed that diminished serum sRAGE was independently associated with poor survival (p = 0.009). Moreover, diminished sRAGE was strongly associated with impaired OS in the second cohort (p < 0.001). Multivariate Cox regression analysis including the investigated SNPs revealed an independent correlation of the two interacting promoter SNPs with impaired OS. In conclusion, the soluble forms of RAGE and variants in its genetic locus are prognostic markers for survival in melanoma patients with high risk for progression.

Expression of the receptor for advanced glycation end-products and frequency of polymorphism in lung cancer

Receptor for advanced glycation end products (RAGE) is associated with the pathogenesis of cancer progression. The pathological effects mediated through RAGE are physiologically inhibited by soluble RAGE (sRAGE). The aim of the present study was to identify the expression of the sRAGE, RAGE and RAGE ligands in serum samples and lung cancer tissue obtained from lung cancer patients. Using ELISA and immunohistochemistry, it was observed that the sRAGE levels were downregulated in the serum, the expression of RAGE was decreased in the lung cancer tissue and the RAGE ligands HMGB1 and S100 were upregulated in cancer tissue. Furthermore, the presence of several selected types of RAGE polymorphism that occur in lung cancers were measured in the tissue samples. An association between the -429T/C and 2184A/G polymorphisms of RAGE and the genesis and progression of lung cancer was identified. The comparison between various histological subtypes and stages of lung cancer was performed with the aim to clarify the biological role of the RAGE gene, and identify a biomarker to aid diagnosis and predict the prognosis for lung cancer patients.

Overexpression of the Receptor for Advanced Glycation Endproducts (RAGE) is associated with poor prognosis in gastric cancer

BACKGROUND

The receptor for advanced glycation endproducts (RAGE) is an oncogenic multidisciplinary trans-membranous receptor, which is overexpressed in multiple human cancers. Recently, it has been shown that RAGE is also involved in carcinogenesis and tumor invasion. In this study, we investigated the expression levels and prognostic value of RAGE in primary gastric cancers (GC).

METHODS

We investigated RAGE expression in primary GC and paired normal gastric tissue by real-time quantitative RT-PCR (n = 30) and Western blotting analysis (n = 30). Additionally, we performed immunohistochemistry on 180 paraffin-embedded GC specimens, 69 matched normal specimens.

RESULTS

RAGE was overexpressed in GC compared with the adjacent noncancerous tissues (P＜0.001), and higher RAGE expression significantly correlated with the histological grade (P = 0.002), nodal status(P = 0.025), metastasis status(P = 0.002), and American Joint Committee on Cancer stage (P = 0.020). Furthermore, upregulation of RAGE expression is an independent prognostic factor in multivariate analysis using the Cox regression model (P = 0.001).

CONCLUSIONS

RAGE Overexpression may be a useful marker to predict GC progression and poor prognosis.

Association of RAGE polymorphisms and cancer risk: a meta-analysis of 27 studies

The receptor for advanced glycation end products (RAGE), a member of immunoglobulin superfamily, has been proved to stimulate survival, growth, and metastatic spread of cancers cells. Evidence suggested that the 82G/S, -374T/A, and -429T/C polymorphisms in RAGE promoter region might affect the risk of cancer; however, data from epidemiological studies showed conflicting results that remain to be further clarified. This meta-analysis was performed to derive a more precise estimation of 82G/S, -374T/A, and -429T/C polymorphisms and risk of cancer. A comprehensive electronic search was conducted for articles published up until December 2, 2014, in Medline (PubMed), Embase, the Cochrane Library and Google Scholar. A total of 12 case-control articles were included in this meta-analysis, providing 3,374 cases and 3,757 controls for 82G/S, 2,936 cases and 3,338 controls for -374T/A, and 2,882 cases and 3,279 controls for -429T/C specifically. The pooled odds ratio (OR) with 95 % confidence interval (CI) was calculated to evaluate the associations with risk of cancer. Overall, we observed significantly increased risk of cancer in relation to 82G/S (A vs. G: OR 1.321, 95 % CI 1.164-1.499, P het 0.028; AA vs. GG: OR 1.823, 95 % CI 1.541-2.157, P het < 0.001; AG vs. GG: OR 1.399, 95 % CI 1.120-1.746, P het 0.002; GA+AA vs. GG: OR 1.470, 95 % CI 1.187-1.821, P het 0.002; AA vs. GG+AG: OR 1.416, 95 % CI 1.158-1.732, P het 0.107) and reduced risk of cancer in relation to -374T/A (AA vs. TT: OR 0.818, 95 % CI 0.686-0.976, P het 0.025; A vs. T: OR 0.908, 95 % CI 0.840-0.981, P het 0.014). In subgroup analysis for 82G/S, a significantly elevated cancer risk was indicated in the population of Asian and patients with lung cancer, and for -374T/A, reduced risk was indicated in population of Caucasian and patients with lung cancer and breast cancer. But no significant association was observed between -429T/C and risk of cancer. Thus, this meta-analysis revealed that 82G/S polymorphism is associated with a significantly increased risk of cancer, while -374T/A polymorphism is associated with a reduced risk of cancers.

Expression of RAGE and HMGB1 in thymic epithelial tumors, thymic hyperplasia and regular thymic morphology

Recently, a role of the receptor for advanced glycation endproducts (RAGE) in myasthenia gravis was described. RAGE and its ligand high mobility group box 1 (HMGB1) play key roles in autoimmunity and cancer. To test whether these molecules are involved in patients with thymic abnormalities we applied immunohistochemical analysis in 33 cases of thymic epithelial tumors, comprising 27 thymomas and 6 thymic carcinomas, and 21 nonneoplastic thymuses. Both molecules were detected in neoplastic epithelial cells: RAGE staining was most intense in WHO type B2 thymomas and thymic carcinomas (p<0.001). HMGB1 nuclear staining was strongest in A and AB, and gradually less in B1 = B2>B3>thymic carcinoma (p<0.001). Conversely, HMGB1 cytoplasmic staining intensities were as follows: A and AB (none), B1 (strong), B2 (moderate), B3 and thymic carcinoma (weak); (p<0.001). Fetal thymic tissue showed a distinct expression of RAGE and HMGB1 in subcapsular cortical epithelial cells which was found in 50% of myasthenic patients. Furthermore RAGE and HMGB1 were expressed in thymocytes, macrophages, Hassall's corpuscles, thymic medulla, and germinal center cells in myasthenic patients. Immunohistochemistry results were complemented by systemic measurements (immunosorbent assay): serum levels of soluble RAGE were significantly reduced in patients with epithelial tumors (p = 0.008); and in invasive tumors (p = 0.008). Whereas RAGE was equally reduced in thymic hyperplasia and epithelial tumors (p = 0.003), HMGB1 was only elevated in malignancies (p = 0.036). Results were most pronounced in thymic carcinomas. Thus, RAGE and HMGB1 are involved in the (patho-)physiology of thymus, as evidenced by differentiated thymic and systemic expression patterns that may act as diagnostic or therapeutic targets in autoimmune disease and cancer.

Association of epidermal growth factor receptor (EGFR) gene polymorphism with lung cancer risk: a systematic review

Epidermal growth factor receptor (EGFR) is a member of the tyrosine kinase receptor family, which is thought to be involved in the development of cancer, as the EGFR gene is often amplified, and/or mutated in cancer cells. Lung cancer remains one of the most major causes of morbidity and mortality worldwide, accounting for more deaths than any other cancer cause. Gene polymorphism factor has been reported to be an important factor which increases the susceptibility of lung cancer. There lacks a well-documented diagnostic approach for the lung cancer risk, and the etiology of lung cancer is not clear. The current systematic review was performed to explore the association of EGFR gene polymorphism with lung cancer risk. In this review, association of EGFR 181946C > T, 8227G > A gene polymorphism with lung cancer was found, and EGFR Short genotype of cytosine adenine repeat number polymorphism was significantly associated with an increased risk of lung cancer.

Association of RAGE gene polymorphisms with sporadic Parkinson's disease in Chinese Han population

Previous studies have corroborated receptor for advanced glycation end-products (RAGE) ablation had a protective effect on nigral dopaminergic neurons in the MPTP model of Parkinson's disease (PD). Genetic variation of RAGE gene may be associated with the development of onset of sporadic PD. The present study aimed to explore the possible association of RAGE gene polymorphisms namely -374T/A,-429T/C, and G82S with PD. A total of 285 PD patients and 285 healthy-matched individuals in Chinese Han population were enrolled. Genotype analyses were performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Only the -429T/C polymorphism denoted a significant difference between PD patients and controls (P=0.015) of the three examined single nucleotide polymorphisms (SNPs). Our data also revealed that -429C allele carriers seem to have a decreased risk of PD (OR=0.617, P=0.007). Moreover, there were significant differences in genotype distribution in female PD group and its healthy-matched control subgroup (P=0.014), as well as between late-onset PD (LOPD) and the controls subgroup (P=0.016). However, for -374T/A and 82GS polymorphisms, there was no significant difference in the genotype and allele frequencies between PD patients and the controls, as well as gender- and age-related differences. Our present findings indicate that the RAGE -429T/C polymorphism may be associated with the susceptibility of PD and the CC genotype of -429T/C may be a protective factor for PD in Chinese Han population.

Knockdown of RAGE inhibits growth and invasion of gastric cancer cells

The receptor for advanced glycation endproducts (RAGE) is an oncogenic trans-membranous receptor, which is overexpressed in multiple human cancers. However, the role of RAGE in gastric cancer is still elusive. In this study, we investigated the expression and molecular mechanisms of RAGE in gastric cancer cells. Forty cases of gastric cancer and corresponding adjacent non-cancerous tissues (ANCT) were collected, and the expression of RAGE was assessed using immunohistochemistry (IHC) in biopsy samples. Furthermore, RAGE signaling was blocked by constructed recombinant small hairpin RNA lentiviral vector (Lv-shRAGE) used to transfect into human gastric cancer SGC-7901 cells. The expression of AKT, proliferating cell nuclear antigen (PCNA) and matrix metallopeptidase-2 (MMP-2) was detected by Real-time PCR and Western blot assays. Cell proliferative activities and invasive capability were respectively determined by MTT and Transwell assays. Cell apoptosis and cycle distribution were analyzed by flow cytometry. As a consequence, RAGE was found highly expressed in cancer tissues compared with the ANCT (70.0% vs 45.0%, P=0.039), and correlated with lymph node metastases (P=0.026). Knockdown of RAGE reduced cell proliferation and invasion of gastric cancer with decreased expression of AKT, PCNA and MMP-2, and induced cell apoptosis and cycle arrest. Altogether, upregulation of RAGE expression is associated with lymph node metastases of gastric cancer, and blockade of RAGE signaling suppresses growth and invasion of gastric cancer cells through AKT pathway, suggesting that RAGE may represent a potential therapeutic target for this aggressive malignancy.

A meta-analysis of the relationship between glutathione S-transferase T1 null/presence gene polymorphism and the risk of lung cancer including 31802 subjects

The relationship between glutathione S-transferase T1 (GSTT1) null/presence gene polymorphism and the risk of lung cancer from the published reports are still conflicting. This study was conducted to evaluate the relationship between GSTT1 null/presence gene polymorphism and the risk of lung cancer using meta-analysis method. The association studies were identified from PubMed, and Cochrane Library on July 1, 2012, and eligible investigations were included and synthesized using meta-analysis method. 51 reports were recruited into this meta-analysis for the association of null genotype of GSTT1 with lung cancer susceptibility, consisting of 15,140 patients with lung cancer and 16,662 controls. There was a marked association between GSTT1 null genotype and lung cancer risk in overall populations (OR = 1.15, 95 % CI 1.04-1.27, P = 0.007). Furthermore, GSTT1 null genotype was associated with the lung cancer risk in Asians (OR = 1.47, 95 % CI 1.23-1.76, P < 0.0001). However, GSTT1 null genotype was not associated with the risk of lung cancer in Caucasians, Brazilian population and Africans. In conclusion, GSTT1 null genotype is associated with the lung cancer in overall populations and in Asians.