GAGE, an Antiapoptotic Protein Binds and Modulates the Expression of Nucleophosmin/B23 and Interferon Regulatory Factor 1

Biology of Cancer-Testis Antigens and Their Therapeutic Implications in Cancer

Tumour-specific antigens have been an area of interest in cancer therapy since their discovery in the middle of the 20th century. In the era of immune-based cancer therapeutics, redirecting our immune cells to target these tumour-specific antigens has become even more relevant. Cancer-testis antigens (CTAs) are a class of antigens with an expression specific to the testis and cancer cells. CTAs have also been demonstrated to be expressed in a wide variety of cancers. Due to their frequency and specificity of expression in a multitude of cancers, CTAs have been particularly attractive as cancer-specific therapeutic targets. There is now a rapid expansion of CTAs being identified and many studies have been conducted to correlate CTA expression with cancer and therapy-resistant phenotypes. Furthermore, there is an increasing number of clinical trials involving using some of these CTAs as molecular targets in pharmacological and immune-targeted therapeutics for various cancers. This review will summarise the current knowledge of the biology of known CTAs in tumorigenesis and the regulation of CTA genes. CTAs as molecular targets and the therapeutic implications of these CTA-targeted anticancer strategies will also be discussed.

Development and validation of a prediction model for malignant pulmonary nodules: A cohort study

This study is to develop and validate a preoperative prediction model for malignancy of solitary pulmonary nodules. Data from 409 patients who underwent solitary pulmonary nodule resection at the First Affiliated Hospital of Nanjing Medical University, China between June 2018 and December 2020 were retrospectively collected. Then, the patients were nonrandomly split into a training cohort and a validation cohort. Clinical features, imaging parameters and laboratory data were then collected. Logistic regression analysis was used to develop a prediction model to identify variables significantly associated with malignant pulmonary nodules (MPNs) that were then included in the nomogram. We evaluated the discrimination and calibration ability of the nomogram by concordance index and calibration plot, respectively. MPNs were confirmed in 215 (52.6%) patients by a pathological examination. Multivariate logistic regression analysis identified 6 risk factors independently associated with MPN: gender (female, odds ratio [OR] = 2.487; 95% confidence interval [CI]: 1.313-4.711; P = .005), location of nodule (upper lobe of lung, OR = 1.126; 95%CI: 1.054-1.204; P < .001), density of nodule (pure ground glass, OR = 4.899; 95%CI: 2.572-9.716; P < .001; part-solid nodules, OR = 6.096; 95%CI: 3.153-14.186; P < .001), nodule size (OR = 1.193; 95%CI: 1.107-1.290; P < .001), GAGE7 (OR = 1.954; 95%CI: 1.054-3.624; P = .033), and GBU4-5 (OR = 2.576; 95%CI: 1.380-4.806; P = .003). The concordance index was 0.86 (95%CI: 0.83-0.91) and 0.88 (95%CI: 0.84-0.94) in the training and validation cohorts, respectively. The calibration curves showed good agreement between the predicted risk by the nomogram and real outcomes. We have developed and validated a preoperative prediction model for MPNs. The model could aid physicians in clinical treatment decision making.

Autoantibodies to tumor-associated antigens in lung cancer diagnosis

Lung cancer (LC) accounts for the majority of cancer-related deaths worldwide. Although screening the high-risk population by low-dose CT (LDCT) has reduced mortality, the cost and high false positivity rate has prevented its general diagnostic use. As such, better and more specific minimally invasive biomarkers are needed in general and for early LC detection, specifically. Autoantibodies produced by humoral immune response to tumor-associated antigens (TAA) are emerging as a promising noninvasive biomarker for LC. Given the low sensitivity of any one single autoantibody, a panel approach could provide a more robust and promising strategy to detect early stage LC. In this review, we summarize the background of TAA autoantibodies (TAAb) and the techniques currently used for identifying TAA, as well as recent findings of LC specific antigens and TAAb. This review provides guidance toward the development of accurate and reliable TAAb as immunodiagnostic biomarkers in the early detection of LC.

GAGE7B promotes tumor metastasis and growth via activating the p38δ/pMAPKAPK2/pHSP27 pathway in gastric cancer

Background

Gastric cancer is the second most common cause of cancer-related mortality; thus, the mechanisms underlying tumor metastasis and growth in gastric cancer need to be extensively explored.

Methods

Differentially expressed genes were examined in gastric cancer samples with lymph node metastasis (LNM) and without LNM using mRNA microarray and RT-qPCR. The effects of G antigen 7B (GAGE7B) on the metastasis, growth, and angiogenesis of gastric cancer were investigated in vitro and in vivo. GAGE7B protein expression was detected by immunohistochemical (IHC) analysis. Microarray, RT-qPCR, and western blot assays were performed to detect downstream target genes of GAGE7B. Dual-luciferase reporter and western blot assays were used to identify miRNAs that could negatively regulate GAGE7B.

Results

GAGE7B was significantly overexpressed in samples with LNM. High expression levels of GAGE7B were associated with advanced clinical stage and poor patient survival. GAGE7B dramatically enhanced the metastasis, growth, and angiogenesis ability of gastric cancer. GAGE7B was further demonstrated to promote the progression of gastric cancer by activating the p38δ/pMAPKAPK2/pHSP27 pathway. However, the GAGE7B-induced p38δ/pMAPKAPK2/pHSP27 pathway was inactivated by miR-30c, as the expression levels of both GAGE7B and p38δ were found to be directly suppressed by miR-30c. Intriguingly, GAGE7B was found to be a ceRNA for p38δ, as it activated the p38δ/pMAPKAPK2/pHSP27 pathway by competitively binding miR-30c.

Conclusions

GAGE7B may serve as a prognostic indicator in gastric cancer. GAGE7B significantly promotes gastric cancer progression by upregulating the p38δ/pMAPKAPK2/pHSP27 pathway, but it is negatively regulated by miR-30c. GAGE7B and miR-30c may be potential therapeutic targets in gastric cancer.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1125-z) contains supplementary material, which is available to authorized users.

Cancer-testis antigens: Unique cancer stem cell biomarkers and targets for cancer therapy

Cancer-testis antigens (CTAs) are considered as unique and promising cancer biomarkers and targets for cancer therapy. CTAs are multifunctional protein group with specific expression patterns in normal embryonic and adult cells and various types of cancer cells. CTAs are involved in regulating of the basic cellular processes during development, stem cell differentiation and carcinogenesis though the biological roles and cell functions of CTA families remain largely unclear. Analysis of CTA expression patterns in embryonic germ and somatic cells, pluripotent and multipotent stem cells, cancer stem cells and their cell descendants indicates that rearrangements of characteristic CTA profiles (aberrant expression) could be associated with cancer transformation and failure of the developmental program of cell lineage specification and germ line restriction. Therefore, aberrant CTA profiles can be used as panels of biomarkers for diagnoses and the selection of cancer treatment strategies. Moreover, immunogenic CTAs are prospective targets for cancer immunotherapy. Clinical trials testing broad range of cancer therapeutic vaccines against antigens of MAGEA and NY-ESO-1 families for treating various cancers have shown mixed clinical efficiency, safety and tolerability, suggesting the requirement of in-depth research of CTA expression in normal and cancer stem cells and extensive clinical trials for improving cancer immunotherapy technologies. This review focuses on recent advancement in study of CTAs in normal and cancer cells, particularly in normal and cancer stem cells, and provides a new insight into CTA expression patterns during normal and cancer stem cell lineage development. Additionally, new approaches in development of effective CTA-based therapies exclusively targeting cancer stem cells will be discussed.

Interferon regulatory factor 1 inactivation in human cancer

Interferon regulatory factors (IRFs) are a group of closely related proteins collectively referred to as the IRF family. Members of this family were originally recognized for their roles in inflammatory responses; however, recent research has suggested that they are also involved in tumor biology. This review focusses on current knowledge of the roles of IRF-1 and IRF-2 in human cancer, with particular attention paid to the impact of IRF-1 inactivation. The different mechanisms underlying IRF-1 inactivation and their implications for human cancers and the potential importance of IRF-1 in immunotherapy are also summarized.

Both high expression of nucleophosmin/B23 and CRM1 predicts poorer prognosis in human gastric cancer

Nucleophosmin/B23 and CRM1 are molecular markers which play an important role in tumorigenesis and tumor progression in gastric cancer (GC). However, the association between the two remains unclear. This study evaluated the expression and the correlation of B23 and CRM1 in GC. B23 and CRM1 expression in GC and adjacent noncancerous tissues (ANCT) of gastrectomy specimens from 131 GC patients was measured by immunohistochemistry. Positive expression rates of B23 and CRM1 were significantly higher in GC tissues than in ANCT. The high expression rates of B23 and CRM1 were significantly higher in patients with more advanced tumor stages and distant metastasis (all p < 0.05). Only high expression of CRM1was correlated with positive Her2 status (p = 0.01). B23 expression was positively correlated with CRM1expression in GC tissues (p = 0.038). Univariate analysis showed that TNM stage (p = 0.0001), metastasis (p = 0.027), B23 (p = 0.0111), and CRM1 expression (p = 0.0019) were significant risk factors affecting overall survival. Both high expression of B23 and CRM1 in GC patients suggests poor prognosis, co-expression of the two (p = 0.043) even worse. Cox multivariate analysis showed that positive B23 (p = 0.0231) and CRM1 (p = 0.0048) expression were both independent prognostic factors that negatively correlated with survival. We revealed the co-expression of B23 or CRM1 in GC. The expression levels of B23 or CRM1 were closely related to poor prognosis in GC, and both B23 or CRM1 were independent risk factor.

Intrapleural Adenoviral-mediated Endothelial Cell Protein C Receptor Gene Transfer Suppresses the Progression of Malignant Pleural Mesothelioma in a Mouse Model

Malignant pleural mesothelioma (MPM) is an aggressive thoracic cancer with a high mortality rate as it responds poorly to standard therapeutic interventions. Our recent studies showed that expression of endothelial cell protein C receptor (EPCR) in MPM cells suppresses tumorigenicity. The present study was aimed to investigate the mechanism by which EPCR suppresses MPM tumor growth and evaluate whether EPCR gene therapy could suppress the progression of MPM in a mouse model of MPM. Measurement of cytokines from the pleural lavage showed that mice implanted with MPM cells expressing EPCR had elevated levels of IFNγ and TNFα compared to mice implanted with MPM cells lacking EPCR. In vitro studies demonstrated that EPCR expression renders MPM cells highly susceptible to IFNγ + TNFα-induced apoptosis. Intrapleural injection of Ad.EPCR into mice with an established MPM originating from MPM cells lacking EPCR reduced the progression of tumor growth. Ad.EPCR treatment elicited recruitment of macrophages and NK cells into the tumor microenvironment and increased IFNγ and TNFα levels in the pleural space. Ad.EPCR treatment resulted in a marked increase in tumor cell apoptosis. In summary, our data show that EPCR expression in MPM cells promotes tumor cell apoptosis, and intrapleural EPCR gene therapy suppresses MPM progression.

Nucleophosmin: from structure and function to disease development

Nucleophosmin (NPM1) is a critical cellular protein that has been implicated in a number of pathways including mRNA transport, chromatin remodeling, apoptosis and genome stability. NPM1 function is a critical requirement for normal cellular biology as is underlined in cancer where NPM1 is commonly overexpressed, mutated, rearranged and sporadically deleted. Consistent with a multifunctional role within the cell, NPM1 can function not only as a proto-oncogene but also as a tumor suppressor. The aim of this review is to look at the less well-described role of NPM1 in the DNA repair pathways as well as the role of NPM1 in the regulation of apoptosis and its mutation in cancers.

Oncogenic cancer/testis antigens: prime candidates for immunotherapy

Recent developments have set the stage for immunotherapy as a supplement to conventional cancer treatment. Consequently, a significant effort is required to further improve efficacy and specificity, particularly the identification of optimal therapeutic targets for clinical testing. Cancer/testis antigens are immunogenic, highly cancer-specific, and frequently expressed in various types of cancer, which make them promising candidate targets for cancer immunotherapy, including cancer vaccination and adoptive T-cell transfer with chimeric T-cell receptors. Our current understanding of tumor immunology and immune escape suggests that targeting oncogenic antigens may be beneficial, meaning that identification of cancer/testis antigens with oncogenic properties is of high priority. Recent work from our lab and others provide evidence that many cancer/testis antigens, in fact, have oncogenic functions, including support of growth, survival and metastasis. This novel insight into the function of cancer/testis antigens has the potential to deliver more effective cancer vaccines. Moreover, immune targeting of oncogenic cancer/testis antigens in combination with conventional cytotoxic therapies or novel immunotherapies such as checkpoint blockade or adoptive transfer, represents a highly synergistic approach with the potential to improve patient survival.

Ectopic expression of embryonic stem cell and other developmental genes in cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma (CTCL) is a potentially devastating malignancy. The pathogenesis of this cancer remains poorly elucidated. Previous studies focused on analysis of expression and function of known oncogenes and tumor suppressor genes. However, emerging reports highlight that it is also important to analyze the expression of genes that are ectopically expressed in CTCL (e.g., embryonic stem cell genes (ESC), cancer testis (CT) genes, etc.). Currently, it is not known whether ESC genes are expressed in CTCL. In the current work, we analyze by RT-PCR the expression of 26 ESC genes, many of which are known to regulate pluripotency and promote cancer stem cell-like phenotype, in a historic cohort of 60 patients from Boston and in a panel of 11 patient-derived CTCL cell lines and compare such expression to benign inflammatory dermatoses that often clinically mimic CTCL. Our findings document that many critical ESC genes including NANOG, SOX2, OCT4 (POU5F1) and their upstream and downstream signaling members are expressed in CTCL. Similarly, polycomb repressive complex 2 (PRC2) genes (i.e., EZH2, EED, and SUZ12) are also expressed in CTCL lesional skin. Furthermore, select ESC genes (OCT4, EED, TCF3, THAP11, CHD7, TIP60, TRIM28) are preferentially expressed in CTCL samples when compared to benign skin biopsies. Our work suggests that ESC genes are ectopically expressed together with CT genes, thymocyte development genes and B cell-specific genes and may be working in concert to promote tumorigenesis. Specifically, while ESC genes may be promoting cancer stem cell-like phenotype, CT genes may be contributing to aneuploidy and genomic instability by producing aberrant chromosomal translocations. Further analysis of ESC expression and function in this cancer will greatly enhance our fundamental understanding of CTCL and will help us identify novel therapeutic targets.

GAGE12 mediates human gastric carcinoma growth and metastasis

The spontaneous metastasis from human gastric carcinoma (GC) remains poorly reproduced in animal models. Here, we established an experimental mouse model in which GC progressively developed in the orthotopic stomach wall and metastasized to multiple organs; the tumors colonized in the ovary exhibited typical characteristics of Krukenberg tumor. The expression of mesenchymal markers was low in primary tumors and high in those in intravasating and extravasating veins. However, the expression of epithelial markers did not differ, indicating that the acquisition of mesenchymal markers without a concordant loss of typical epithelial markers was associated with metastasis. We identified 35 differentially expressed genes (DEGs) in GC cells metastasized to ovary, among which overexpression of GAGE12 family genes, the top-ranked DEGs, were validated. In addition, knockdown of the GAGE12 gene family affected transcription of many of the aforementioned 35 DEGs and inhibited trans-well migration, tumor sphere formation in vitro and tumor growth in vivo. In accordance, GAGE12 overexpression augmented migration, tumor sphere formation and sustained in vivo tumor growth. Taken together, the GAGE12 gene family promotes GC growth and metastasis by modulating the expression of GC metastasis-related genes.

Generation and characterization of an immortalized human mesenchymal stromal cell line

Human mesenchymal stromal cells (hMSCs) show great potential for clinical and experimental use due to their capacity to self-renew and differentiate into multiple mesenchymal lineages. However, disadvantages of primary cultures of hMSCs are the limited in vitro lifespan, and the variable properties of cells from different donors and over time in culture. In this article, we describe the generation of a telomerase-immortalized nontumorigenic human bone marrow-derived stromal mesenchymal cell line, and its detailed characterization after long-term culturing (up to 155 population doublings). The resulting cell line, iMSC#3, maintained a fibroblast-like phenotype comparable to early passages of primary hMSCs, and showed no major differences from hMSCs regarding surface marker expression. Furthermore, iMSC#3 had a normal karyotype, and high-resolution array comparative genomic hybridization confirmed normal copy numbers. The gene expression profiles of immortalized and primary hMSCs were also similar, whereas the corresponding DNA methylation profiles were more diverse. The cells also had proliferation characteristics comparable to primary hMSCs and maintained the capacity to differentiate into osteoblasts and adipocytes. A detailed characterization of the mRNA and microRNA transcriptomes during adipocyte differentiation also showed that the iMSC#3 recapitulates this process at the molecular level. In summary, the immortalized mesenchymal cells represent a valuable model system that can be used for studies of candidate genes and their role in differentiation or oncogenic transformation, and basic studies of mesenchymal biology.

Ectopic expression of cancer-testis antigens in cutaneous T-cell lymphoma patients

PURPOSE

The pathogenesis of cutaneous T-cell lymphoma (CTCL) remains only partially understood. A number of recent studies attempted to identify novel diagnostic markers and future therapeutic targets. One group of antigens, cancer-testis (CT) antigens, normally present solely in testicular germ cells, can be ectopically expressed in a variety of cancers. Currently, only a few studies attempted to investigate the expression of CT antigens in CTCL.

EXPERIMENTAL DESIGN

In the present work, we test the expression of CT genes in a cohort of patients with CTCL, normal skin samples, skin from benign inflammatory dermatoses, and in patient-derived CTCL cells. We correlate such expression with the p53 status and explore molecular mechanisms behind their ectopic expression in these cells.

RESULTS

Our findings demonstrate that SYCP1, SYCP3, REC8, SPO11, and GTSF1 genes are heterogeneously expressed in patients with CTCL and patient-derived cell lines, whereas cTAGE1 (cutaneous T-cell lymphoma-associated antigen 1) was found to be robustly expressed in both. Mutated p53 status did not appear to be a requirement for the ectopic expression of CT antigens. While T-cell stimulation resulted in a significant upregulation of STAT3 and JUNB expression, it did not significantly alter the expression of CT antigens. Treatment of CTCL cells in vitro with vorinostat or romidepsin histone deacetylase inhibitors resulted in a significant dose-dependent upregulation of mRNA but not protein. Further expression analysis demonstrated that SYCP1, cTAGE1, and GTSF1 were expressed in CTCL, but not in normal skin or benign inflammatory dermatoses.

CONCLUSIONS

A number of CT genes are ectopically expressed in patients with CTCL and can be used as biomarkers or novel targets for immunotherapy.

Effects of CT-Xp gene knock down in melanoma cell lines

Cancer/testis (CT) genes are encoded by genes that are normally expressed only in the human germ line but which are activated in various malignancies. CT proteins are frequently immunogenic in cancer patients and their expression is highly restricted to tumors. They are thus important targets for anticancer immunotherapy. In several different tumor types, the expression of CT-X genes is associated with advanced disease and poor outcome, indicating that their expression might contribute to tumorigenesis. CT-X genes encoding members of the MAGE protein family on Xq28 have been shown to potentially influence the tumorigenic phenotype. We used small interfering RNA (siRNA) to investigate whether CT-X mapping to the short arm of the X-chromosome might also have tumorigenic properties and therefore be potentially targeted by functional inhibitors in a therapeutic setting. siRNAs specific to GAGE, SSX and XAGE1 were used in cell proliferation, migration and cell survival assays using cell lines derived from melanoma, a tumor type known to present high frequencies of expression of CT antigens. We found that of these, those specific to GAGE and XAGE1 most significantly impeded melanoma cell migration and invasion and those specific to SSX4 and XAGE1 decreased the clonogenic survival of melanoma cells. Our results suggest that GAGE, XAGE1 and SSX4 might each have a role in tumor progression and are possible therapeutic targets for the treatment of melanoma and other malignancies.

Clinical significance of nucleophosmin/B23 and human epidermal growth factor receptor 2/neu expressions in gastric cancers

The aim of the study was to investigate the expression levels of 'NPM'/nucleophosmin/B23 and human epidermal growth factor receptor 2 (Her-2)/neu in gastric cancer (GC) and corresponding non-malignant tissues, correlation with their clinicopathological parameters and the relationship of nucleophosmin/B23 and Her-2/neu in the occurrence and development of GC. A total of 131 postoperative patients were examined for nucleophosmin/B23 expression by immuno-histochemistry and for Her-2/neu expression by fluorescence in situ hybridization with the median follow-up period of 38 months. The positive expression rates of nucleophosmin (NPM) in neoplastic tissues and adjacent gastric mucosa were 65.6% and 52.7%, respectively. Nucleophosmin/B23 levels were linked to more advanced tumor stages, poor prognosis, and likelihood of recurrence (p < 0.05). The Cox multivariate analysis indicated that the nucleophosmin/B23 expression was an independent indicator for tumor recurrence (p = 0.011). Of the total GC specimens 12.21% were positive for Her-2/neu, but whose expression was of no correlation with patients' survival. Patients who were positive for Her-2/neu also had high NPM expression levels (p = 0.0303). The results suggest that nucleophosmin/B23 is a favorable prognostic indicator for GC. But Her-2/neu has no relationship with the prognosis of GC. The combined clinical significance of nucleophosmin/B23 and Her-2/neu remains to be further investigated.

Heterogeneous expression of CT10, CT45 and GAGE7 antigens and their prognostic significance in human breast carcinoma

OBJECTIVE

The goal of this study was to detect the intertumoral heterogeneity of CT10, CT45 and GAGE7 expression and further to analyze their prognostic value.

METHODS

The intertumoral heterogeneity of three cancer/testis antigens was examined by immunohistochemistry using 120 samples from patients with infiltrating ductal breast carcinoma. The expression patterns were classified and correlated with the clinicopathologic variables and outcome of the patients.

RESULTS

CT10 showed punctate, focal and diffuse expression patterns according to the characteristic of its distribution. CT45 showed cytoplasmic, nuclear or combined cytoplasmic and nuclear expression patterns according to its subcellular location. GAGE7 exhibited nuclear, cytoplasmic and nucleolar expression patterns. Three cancer/testis antigens were also observed coordinately expressed in infiltrating ductal breast carcinoma. Patients with tumors with CT10 expression was significantly correlated with nodal metastases (P < 0.001) and advanced clinical stages (P = 0.001). Patients with tumors with cytoplasmic GAGE7 and with the expression of two or more cancer/testis antigens were significantly correlated with advanced clinical stages (P = 0.001 and P = 0.030). No significant difference was identified between the different expression patterns of CT45 and clinicopathologic variables. In addition, Kaplan-Meier analysis revealed that diffuse CT10 expression and coexpression of three cancer/testis antigens were related to the poor prognosis of patients with infiltrating ductal breast carcinoma.

CONCLUSIONS

Diffuse CT10 expression and the coexpression of three cancer/testis antigens can be used as a biomarker to distinguish patients with a poorer outcome of the breast carcinoma. Our finding may provide useful data for evaluating the prognosis of this disease and improving the effectiveness of therapeutic application based on the three cancer/testis antigens.

Melanoma-associated cancer-testis antigen 16 (CT16) regulates the expression of apoptotic and antiapoptotic genes and promotes cell survival

Cancer-testis (CT) antigens are predominantly expressed in testis or placenta, but absent in most adult tissues. During malignant transformation CT genes are often activated. CT antigen 16 (CT16, PAGE5) is frequently expressed in advanced melanoma but its biological function has been unknown. To examine the role of CT16 in cell survival we knocked it down in A2058 melanoma cells using specific siRNAs and exposed the cells to cancer drug cisplatin known to induce apoptosis. As a result, cell survival was markedly decreased. To study the effects of CT16 on cell survival in more detail, the cellular gene expression profiles were investigated after CT16 silencing in CT16 positive A2058 melanoma cells, as well as after CT16 overexpression in CT16 negative WM-266-4 melanoma cells. Among the 11 genes both upregulated by CT16 silencing and downregulated by CT16 overexpression or vice versa, 4 genes were potentially apoptotic or antiapoptotic genes. CT16 was recognized as a positive regulator of antiapoptotic metallothionein 2A and interleukin 8 genes, whereas it inhibited the expression of apoptosis inducing dickkopf 1 (DKK1) gene. In addition CT16 enhanced the expression of fatty acid binding protein 7, a known promoter of melanoma progression. The effect of CT16 on DKK1 expression was p53 independent. Furthermore, CT16 did not regulate apoptotic genes via DNA methylation. In twenty melanoma metastasis tissue samples average DKK1 mRNA level was shown to be significantly (p<0.05) lower in high CT16 expressing tumors (n = 3) when compared to the tumors with low CT16 expression (n = 17). Thus, our results indicate that CT16 promotes the survival of melanoma cells and is therefore a potential target for future drug development.

GAGE cancer-germline antigens are recruited to the nuclear envelope by germ cell-less (GCL)

GAGE proteins are highly similar, primate-specific molecules with unique primary structure and undefined cellular roles. They are restricted to cells of the germ line in adult healthy individuals, but are broadly expressed in a wide range of cancers. In a yeast two-hybrid screen we identified the metazoan transcriptional regulator, Germ cell-less (GCL), as an interaction partner of GAGE12I. GCL directly binds LEM-domain proteins (LAP2β, emerin, MAN1) at the nuclear envelope, and we found that GAGE proteins were recruited to the nuclear envelope inner membrane by GCL. Based on yeast two-hybrid analysis and pull-down experiments of GCL polypeptides, GCL residues 209–320 (which includes the BACK domain) were deduced sufficient for association with GAGE proteins. GAGE mRNAs and GCL mRNA were demonstrated in human testis and most types of cancers, and at the protein level GAGE members and GCL were co-expressed in cancer cell lines. Structural studies of GAGE proteins revealed no distinct secondary or tertiary structure, suggesting they are intrinsically disordered. Interestingly GAGE proteins formed stable complexes with dsDNA in vitro at physiological concentrations, and GAGE12I bound several different dsDNA fragments, suggesting sequence-nonspecific binding. Dual association of GAGE family members with GCL at the nuclear envelope inner membrane in cells, and with dsDNA in vitro, implicate GAGE proteins in chromatin regulation in germ cells and cancer cells.

Erythroid differentiation-associated gene interacts with NPM1 (nucleophosmin/B23) and increases its protein stability, resisting cell apoptosis

Erythroid differentiation-associated gene (EDAG) is a haematopoietic tissue-specific transcription regulator that plays a key role in maintaining the homeostasis of haematopoietic lineage commitment. In acute myeloid leukaemia (AML) patients, the high expression level of EDAG is associated with poor prognosis. NPM1 (nucleophosmin/B23), a ubiquitous nucleolar phosphoprotein, comprises a multifunctional protein that is involved in several cellular processes, including ribosome biogenesis, centrosome duplication, cell cycle progression, cell growth and transformation. Various studies have implicated NPM1 overexpression in promoting tumour cell proliferation, blocking the differentiation of leukaemia cells and resisting apoptosis. In the present study, using co-immunoprecipitation, we characterized EDAG as a physiological binding partner of NPM1; The N-terminal (amino acids 1-124) region of EDAG interacts with the N-terminal (amino acids 118-187) of NPM1. Under cycloheximide treatment, the stability of NPM1 protein was enhanced by EDAG overexpression, whereas knockdown of EDAG by lentivirus-mediated small interfering RNA resulted in an increased degradation rate of NPM1 in K562 cells. During 4β-phorbol l2-myristate 13-acetate-induced K562 megakaryocytic differentiation, overexpression of EDAG prevented the down-regulation of NPM1 proteins, whereas knockdown of EDAG accelerated the down-regulation of NPM1. EDAG deletion mutant lacking the binding domain with NPM1 lost the ability to stabilize NPM1 protein. Furthermore, knockdown of EDAG in K562 cells led to increased cell apoptosis induced by imatinib, and re-expression of NPM1 attenuated the increased apoptosis. These results suggest that EDAG enhances the protein stability of NPM1 via binding to NPM1, which plays a critical role in the anti-apoptosis of leukaemia cells.

Genes involved in systemic and arterial bed dependent atherosclerosis--Tampere Vascular study

Background

Atherosclerosis is a complex disease with hundreds of genes influencing its progression. In addition, the phenotype of the disease varies significantly depending on the arterial bed.

Methodology/Principal Findings

We characterized the genes generally involved in human advanced atherosclerotic (AHA type V–VI) plaques in carotid and femoral arteries as well as aortas from 24 subjects of Tampere Vascular study and compared the results to non-atherosclerotic internal thoracic arteries (n=6) using genome-wide expression array and QRT-PCR. In addition we determined genes that were typical for each arterial plaque studied. To gain a comprehensive insight into the pathologic processes in the plaques we also analyzed pathways and gene sets dysregulated in this disease using gene set enrichment analysis (GSEA). According to the selection criteria used (>3.0 fold change and p-value <0.05), 235 genes were up-regulated and 68 genes down-regulated in the carotid plaques, 242 genes up-regulated and 116 down-regulated in the femoral plaques and 256 genes up-regulated and 49 genes down-regulated in the aortic plaques. Nine genes were found to be specifically induced predominantly in aortic plaques, e.g., lactoferrin, and three genes in femoral plaques, e.g., chondroadherin, whereas no gene was found to be specific for carotid plaques. In pathway analysis, a total of 28 pathways or gene sets were found to be significantly dysregulated in atherosclerotic plaques (false discovery rate [FDR] <0.25).

Conclusions

This study describes comprehensively the gene expression changes that generally prevail in human atherosclerotic plaques. In addition, site specific genes induced only in femoral or aortic plaques were found, reflecting that atherosclerotic process has unique features in different vascular beds.

Plasticity and virus specificity of the airway epithelial cell immune response during respiratory virus infection

Airway epithelial cells (AECs) provide the first line of defense in the respiratory tract and are the main target of respiratory viruses. Here, using oligonucleotide and protein arrays, we analyze the infection of primary polarized human AEC cultures with influenza virus and respiratory syncytial virus (RSV), and we show that the immune response of AECs is quantitatively and qualitatively virus specific. Differentially expressed genes (DEGs) specifically induced by influenza virus and not by RSV included those encoding interferon B1 (IFN-B1), type III interferons (interleukin 28A [IL-28A], IL-28B, and IL-29), interleukins (IL-6, IL-1A, IL-1B, IL-23A, IL-17C, and IL-32), and chemokines (CCL2, CCL8, and CXCL5). Lack of type I interferon or STAT1 signaling decreased the expression and secretion of cytokines and chemokines by the airway epithelium. We also observed strong basolateral polarization of the secretion of cytokines and chemokines by human and murine AECs during infection. Importantly, the antiviral response of human AECs to influenza virus or to RSV correlated with the infection signature obtained from peripheral blood mononuclear cells (PBMCs) isolated from patients with acute influenza or RSV bronchiolitis, respectively. IFI27 (also known as ISG12) was identified as a biomarker of respiratory virus infection in both AECs and PBMCs. In addition, the extent of the transcriptional perturbation in PBMCs correlated with the clinical disease severity. Our results demonstrate that the human airway epithelium mounts virus-specific immune responses that are likely to determine the subsequent systemic immune responses and suggest that the absence of epithelial immune mediators after RSV infection may contribute to explaining the inadequacy of systemic immunity to the virus.

The biology of cancer testis antigens: putative function, regulation and therapeutic potential

Cancer testis antigens (CTA) are a large family of tumor-associated antigens expressed in human tumors of different histological origin, but not in normal tissues except for testis and placenta. This tumor-restricted pattern of expression, together with their strong in vivo immunogenicity, identified CTA as ideal targets for tumor-specific immunotherapeutic approaches, and prompted the development of several clinical trials of CTA-based vaccine therapy. Driven by this practical clinical interest, a more detailed characterization of CTA biology has been recently undertaken. So far, at least 70 families of CTA, globally accounting for about 140 members, have been identified. Most of these CTA are expressed during spermatogenesis, but their function is still largely unknown. Epigenetic events, particularly DNA methylation, appear to be the primary mechanism regulating CTA expression in both normal and transformed cells, as well as in cancer stem cells. In view of the growing interest in CTA biology, the aim of this review is to provide the most recent information on their expression, regulation and function, together with a brief summary of the major clinical trials involving CTA as therapeutic agents. The pharmacologic modulation of CTA expression profiles on neoplastic cells by DNA hypomethylating drugs will also be discussed as a feasible approach to design new combination therapies potentially able to improve the clinical efficacy of currently adopted CTA-based immunotherapeutic regimens in cancer patients.

NPM1/B23: A Multifunctional Chaperone in Ribosome Biogenesis and Chromatin Remodeling

At a first glance, ribosome biogenesis and chromatin remodeling are quite different processes, but they share a common problem involving interactions between charged nucleic acids and small basic proteins that may result in unwanted intracellular aggregations. The multifunctional nuclear acidic chaperone NPM1 (B23/nucleophosmin) is active in several stages of ribosome biogenesis, chromatin remodeling, and mitosis as well as in DNA repair, replication and transcription. In addition, NPM1 plays an important role in the Myc-ARF-p53 pathway as well as in SUMO regulation. However, the relative importance of NPM1 in these processes remains unclear. Provided herein is an update on the expanding list of the diverse activities and interacting partners of NPM1. Mechanisms of NPM1 nuclear export functions of NPM1 in the nucleolus and at the mitotic spindle are discussed in relation to tumor development. It is argued that the suggested function of NPM1 as a histone chaperone could explain several, but not all, of the effects observed in cells following changes in NPM1 expression. A future challenge is to understand how NPM1 is activated, recruited, and controlled to carry out its functions.