ANXA7 expression represents hormone-relevant tumor suppression in different cancers

A Dominant-Negative Mutant of ANXA7 Impairs Calcium Signaling and Enhances the Proliferation of Prostate Cancer Cells by Downregulating the IP3 Receptor and the PI3K/mTOR Pathway

Annexin A7/ANXA7 is a calcium-dependent membrane fusion protein with tumor suppressor gene (TSG) properties, which is located on chromosome 10q21 and is thought to function in the regulation of calcium homeostasis and tumorigenesis. However, whether the molecular mechanisms for tumor suppression are also involved in the calcium- and phospholipid-binding properties of ANXA7 remain to be elucidated. We hypothesized that the 4 C-terminal endonexin-fold repeats in ANXA7 (GX(X)GT), which are contained within each of the 4 annexin repeats with 70 amino acids, are responsible for both calcium- and GTP-dependent membrane fusion and the tumor suppressor function. Here, we identified a dominant-negative triple mutant (DNTM/DN-ANXA7J) that dramatically suppressed the ability of ANXA7 to fuse with artificial membranes while also inhibiting tumor cell proliferation and sensitizing cells to cell death. We also found that the [DNTM]ANA7 mutation altered the membrane fusion rate and the ability to bind calcium and phospholipids. In addition, in prostate cancer cells, our data revealed that variations in phosphatidylserine exposure, membrane permeabilization, and cellular apoptosis were associated with differential IP3 receptor expression and PI3K/AKT/mTOR modulation. In conclusion, we discovered a triple mutant of ANXA7, associated with calcium and phospholipid binding, which leads to the loss of several essential functions of ANXA7 pertinent to tumor protection and highlights the importance of the calcium signaling and membrane fusion functions of ANXA7 for preventing tumorigenesis.

ANXA9 as a novel prognostic biomarker associated with immune infiltrates in gastric cancer

Background

Gastric cancer (GC) is the most prevalent malignancy among the digestive system tumors. Increasing evidence has revealed that lower mRNA expression of ANXA9 is associated with a poor prognosis in colorectal cancer. However, the role of ANXA9 in GC remains largely unknown.

Material and Methods

The Gene Expression Profiling Interactive Analysis (GEPIA) and Human Protein Atlas databases were used to investigate the expression of ANXA9 in GC, which was then validated in the four Gene Expression Omnibus (GEO) datasets. The diagnostic value of ANXA9 for GC patients was demonstrated using a receiver operating characteristic (ROC) curve. The correlation between ANXA9 expression and clinicopathological parameters was analyzed in The Cancer Genome Atlas (TCGA) and UALCAN databases. The Kaplan-Meier (K-M) survival curve was used to elucidate the relationship between ANXA9 expression and the survival time of GC patients. We then performed a gene set enrichment analysis (GSEA) to explore the biological functions of ANXA9. The relationship of ANXA9 expression and cancer immune infiltrates was analyzed using the Tumor Immune Estimation Resource (TIMER). In addition, the potential mechanism of ANXA9 in GC was investigated by analyzing its related genes.

Results

ANXA9 was significantly up-regulated in GC tissues and showed obvious diagnostic value. The expression of ANXA9 was related to the age, gender, grade, TP53 mutation, and histological subtype of GC patients. We also found that ANXA9 expression was associated with immune-related biological function. ANXA9 expression was also correlated with the infiltration level of CD8⁺ T cells, neutrophils, and dendritic cells in GC. Additionally, copy number variation (VNV) of ANXA9 occurred in GC patients. Function enrichment analyses revealed that ANXA9 plays a role in the GC progression by interacting with its related genes.

Conclusions

Our results provide strong evidence of ANXA9 expression as a prognostic indicator related to immune responses in GC.

AnnexinA7 promotes epithelial-mesenchymal transition by interacting with Sorcin and contributes to aggressiveness in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and metastasis is the major cause of the high mortality of HCC. In this study, we identified that AnnexinA7 (ANXA7) and Sorcin (SRI) are overexpressed and interacting proteins in HCC tissues and cells. In vitro functional investigations revealed that the interaction between ANXA7 and SRI regulated epithelial–mesenchymal transition (EMT), and then affected migration, invasion, and proliferation in HCC cells. Furthermore overexpression/knockdown of ANXA7 was remarkably effective in promoting/inhibiting tumorigenicity and EMT in vivo. Altogether, our study unveiled a mechanism that ANXA7 promotes EMT by interacting with SRI and further contributes to the aggressiveness in HCC, which provides a novel potential therapeutic target for preventing recurrence and metastasis in HCC.

Permutation-based identification of important biomarkers for complex diseases via machine learning models

Study of human disease remains challenging due to convoluted disease etiologies and complex molecular mechanisms at genetic, genomic, and proteomic levels. Many machine learning-based methods have been developed and widely used to alleviate some analytic challenges in complex human disease studies. While enjoying the modeling flexibility and robustness, these model frameworks suffer from non-transparency and difficulty in interpreting each individual feature due to their sophisticated algorithms. However, identifying important biomarkers is a critical pursuit towards assisting researchers to establish novel hypotheses regarding prevention, diagnosis and treatment of complex human diseases. Herein, we propose a Permutation-based Feature Importance Test (PermFIT) for estimating and testing the feature importance, and for assisting interpretation of individual feature in complex frameworks, including deep neural networks, random forests, and support vector machines. PermFIT (available at https://github.com/SkadiEye/deepTL) is implemented in a computationally efficient manner, without model refitting. We conduct extensive numerical studies under various scenarios, and show that PermFIT not only yields valid statistical inference, but also improves the prediction accuracy of machine learning models. With the application to the Cancer Genome Atlas kidney tumor data and the HITChip atlas data, PermFIT demonstrates its practical usage in identifying important biomarkers and boosting model prediction performance.

Study of human disease remains challenging due to convoluted disease etiologies and complex molecular mechanisms at genetic, genomic, and proteomic levels. Here, the authors propose a computationally efficient Permutation-based Feature Importance Test to assist interpretation and selection of individual features in complex machine learning models for complex disease analysis.

Promoting TTC4 and HSP70 interaction and translocation of annexin A7 to lysosome inhibits apoptosis in vascular endothelial cells

We previously demonstrated that Tetraticopeptide 4 (TTC4) inhibited apoptosis in vascular endothelial cells (VEC) deprived of serum and fibroblast growth factor 2 (FGF-2). In this study, we aimed to resolve the mechanism of TTC4 inhibiting VEC apoptosis. TTC4, predicted as a HSP70 co-chaperone protein, may regulate the fate of cells by affecting the activity of HSP70, however, there is no experimental evidence showing the interaction of TTC4 and HSP70. Using Co-immunoprecipitation (Co-IP), we demonstrated that TTC4 interacted with HSP70. If HSP70 was knockdown, TTC4 no longer suppressed apoptosis. Furthermore, we found ABO, an inhibitor of annexin A7 (ANXA7) GTPase, could promote the interaction of TTC4 and HSP70 and the translocation of ANXA7 to lysosome. At the same time, ABO inhibited the interaction of HSP70 and ANXA7. Moreover, Akt, as a downstream effector of HSP70 was upregulated, and ANXA7 translocating to lysosome protected the stability of lysosomal membrane. Here, we discovered a special mechanism by which TTC4 inhibited apoptosis via HSP70 in VECs. On the one hand, increasing TTC4 and HSP70 interaction upregulated Akt that inhibited apoptosis. On the other hand, decreasing HSP70 and ANXA7 interaction promoted the translocation of ANXA7 to lysosome, which inhibited apoptosis through protecting the lysosomal membrane stability.

ANXA7 promotes the cell cycle, proliferation and cell adhesion-mediated drug resistance of multiple myeloma cells by up-regulating CDC5L

This study aimed to investigate whether annexin A7 (ANXA7) could promote the cell cycle, proliferation and cell adhesion-mediated drug resistance (CAM-DR) of multiple myeloma (MM) cells by up-regulating cell division cycle 5-like (CDC5L). As a result, ANXA7 expression was increased in the serum of MM patients and the expression of ANXA7 and CDC5L was also increased in MM cell lines. ANXA7 overexpression promoted the proliferation and cycle of U266 and RPMI8226 cells. The expression of proliferation cell nuclear antigen (PCNA), KI67, cyclin dependent kinase 1 (CDK1) and cyclinB1 in transfected cells was consistent with the changes of proliferation and cell cycle. In co-culture system of BMSC cells and MM cells, expression of CD44, ICAM1 and VCAM1 in MM cells was increased, which was further increased by ANXA7 overexpression. Bortezomib could increase the apoptosis of U266 and RPMI8226 cells. In co-culture system of BMSC cells and MM cells, the promotion effects of bortezomib on apoptosis of MM cells was decreased, which was further suppressed by ANXA7 overexpression. The above effects exerted by ANXA7 overexpression could be reversed by ANXA7 interference. Moreover, ANXA7 was proved to be combined with CDC5L. CDC5L interference could inhibit the promotion effects of ANXA7 overexpression on proliferation and cell cycle and inhibition effects of ANXA7 overexpression on apoptosis of MM cells treated with bortezomib in co-culture system. In conclusion, ANXA7 could promote the cell cycle, proliferation and CAM-DR of MM cells by up-regulating CDC5L.

Expression levels and prognostic values of annexins in liver cancer

Annexins are a superfamily of calcium-dependent phospholipid-binding proteins that are implicated in a wide range of biological processes. The annexin superfamily comprises 13 members in humans (ANXAs), the majority of which are frequently dysregulated in cancer. However, the expression patterns and prognostic values of ANXAs in liver cancer are currently largely unknown. The present study aimed to analyze the expression levels of ANXAs and survival data in patients with liver cancer from the Oncomine, GEPIA, Kaplan-Meier plotter and cBioPortal for Cancer Genomics databases. The results demonstrated that ANXA1, A2, A3, A4 and A5 were upregulated, whereas ANXA10 was downregulated in liver cancer compared with normal liver tissues. The expression of ANXA10 was associated with pathological stage. High expression levels of ANXA2 and A5 were significantly associated with poor overall survival (OS) rate whereas ANXA7 and A10 were associated with increased OS. The prognostic values of ANXAs in liver cancer were determined based on sex and clinical stage, which revealed that ANXA2, A5, A7 and A10 were associated with OS in male, but not in female patients. In addition, the potential biological functions of ANXAs were identified by Gene Ontology functional annotation and Kyoto Encyclopedia of Genes Genomes pathway analysis; the results demonstrated that ANXAs may serve a role in liver cancer through the neuroactive ligand-receptor interaction pathway. In conclusion, the results of the present study suggested that ANXA1, A2, A3, A4, A5 and A10 may be potential therapeutic targets for liver cancer treatment, and that ANXA2, A5, A7 and A10 may be potential prognostic biomarkers of liver cancer.

AnnexinA7 down-regulation might suppress the proliferation and metastasis of human hepatocellular carcinoma cells via MAPK/ ERK pathway

BACKGROUND

Hepatocellular carcinoma is one of the most fatal malignancies worldwide with high lethality. However, the exact mechanism of liver tumorigenesis is still unclear. AnnexinA7 (ANXA7) is a Ca2+-binding protein which is involved in membrane organization and dynamics and indicated a role of ANXA7 in cancer. However, the action of ANXA7 in hepatocellular carcinoma and the relative mechanism is still indistinct.

OBJECTIVE

To gain more insight into the biological function of ANXA7 and assess its possible influence on proliferation and metastasis capacity of human hepatocellular carcinoma cells with the relative mechanism.

METHODS

ANXA7 was down-regulated by RNA interference in both HepG2 and smmc-7721 cells. The decreased cell proliferation was detected by MTT method and colony formation assay. To confirm the result of cell proliferation, Ki-67 and cyclinD1 expression was examined by Western Blot. The increased apoptosis capacity of the cells was detected with cell cytometry and PI staining respectively. Bcl-2 and Bax expression was further investigated by Western blot and the decreased ration of Bcl-2/Bax might explain the increased apoptosis.

RESULTS

Cell metastasis showed significantly limited ability which was tested by wound healing assay and Transwell assay. Meanwhile, the key biomarkers of cell metastasis E-cadherin expression increased while MMP-9 decreased. Furthermore, we found that ANXA7 played its role via MAPK/ERK pathway.

CONCLUSIONS

ANXA7 might involve in the development of hepatocellular carcinoma and act as an oncogene which might be a potential therapeutic target for treatment.

Tissue microarray analysis delineate potential prognostic role of Annexin A7 in prostate cancer progression

Background

Annexin A7 (ANXA7) is a member of the multifunctional calcium or phospholipid-binding annexin gene family. While low levels of ANXA7 are associated with aggressive types of cancer, the clinical impact of ANXA7 in prostate cancer remains unclear. Tissue microarrays (TMA) have revealed several new molecular markers in human tumors. Herein, we have identified the prognostic impact of ANXA7 in a prostate cancer using a tissue microarray containing 637 different specimens.

Methods

The patients were diagnosed with prostate cancer and long-term follow-up information on progression (median 5.3 years), tumor-specific and overall survival data (median 5.9 years) were available. Expression of Ki67, Bcl-2, p53, CD-10 (neutral endopeptidase), syndecan-1 (CD-138) and ANXA7 were analyzed by immunohistochemistry.

Results

A bimodal distribution of ANXA7 was observed. Tumors expressing either high or no ANXA7 were found to be associated with poor prognosis. However, ANXA7 at an optimal level, in between high and no ANXA7 expression, had a better prognosis. This correlated with low Ki67, Bcl-2, p53 and high syndecan-1 which are known predictors of early recurrence. At Gleason grade 3, ANXA7 is an independent predictor of poor overall survival with a p-value of 0.003. Neoadjuvant hormonal therapy, which is known to be associated with overexpression of Bcl-2 and inhibition of Ki67 LI and CD-10, was found to be associated with under-expression of ANXA7.

Conclusions

The results of this TMA study identified ANXA7 as a new prognostic factor and indicates a bimodal correlation to tumor progression.

Annexin A7 expression is downregulated in late-stage gastric cancer and is negatively correlated with the differentiation grade and apoptosis rate

Annexin A7 is a member of the Annexin A family, which participates in various biological processes. Accumulating evidence has demonstrated that Annexin A7 serves an important role in tumorigenesis and is dysregulated in multiple types of cancer. However, the role of Annexin A7 in the tumorigenesis of gastric cancer remains to be determined. The present study revealed that Annexin A7 expression is downregulated in late-stage gastric cancer and is negatively correlated with the differentiation grade and apoptosis. There was a significant difference in Annexin A7 mRNA and protein expression in gastric cancer samples with distinct differentiation grades, with the lowest expression being observed in the highly differentiated cases. A terminal deoxynucleotidyl-transferase-mediated dUTP nick end labelling assay demonstrated that the apoptosis indices of highly, moderately and poorly differentiated gastric cancers were 18.12±2.40, 9.73±1.73 and 4.13±0.83%, respectively, with statistical significance (P<0.05). Flow cytometric analysis demonstrated that the apoptosis rates of gastric cancer MKN74, SGC7901 and BGC823 cells were 10.07±1.21, 7.11±1.04 and 4.25±1.02%, respectively, with statistical significance (P<0.05). Spearman's rank correlation analysis revealed that the Annexin A7 mRNA and protein levels were negatively correlated with the differentiation grade of the gastric cancer tissues, while the apoptosis index was positively correlated with the differentiation grade of the gastric cancer tissues. Furthermore, the apoptosis index was negatively correlated with Annexin A7 mRNA and protein expression. Similar associations were observed among Annexin A7 expression, differentiation grades and apoptosis in gastric cancer cell lines. The results of the present study demonstrated that Annexin A7 expression is downregulated, while apoptosis is upregulated, with the progression of gastric adenocarcinoma. These observations suggested that Annexin A7 may inhibit apoptosis during tumorigenesis and that it is a potential biomarker for the diagnosis, prognosis and treatment of gastric adenocarcinoma.

Functional Association between Regulatory RNAs and the Annexins

Cells respond to pathophysiological states by activation of stress-induced signalling. Regulatory non-coding microRNAs (miRNAs) often form stable feed-forward loops which ensure prolongation of the signal, contributing to sustained activation. Members of the annexin protein family act as sensors for Ca²⁺, pH, and lipid second messengers, and regulate various signalling pathways. Recently, annexins were reported to participate in feedback loops, suppressing miRNA synthesis and attenuating stress-induced dysregulation of gene expression. They can directly or indirectly associate with RNAs, and are transferred between the cells in exosomes and shed microvesicles. The ability of annexins to recruit other proteins and miRNAs into exosomes implicates them in control of cell–cell interactions, affecting the adaptive responses and remodelling processes during disease. The studies summarized in this Review point to an emerging role of annexins in influencing the synthesis, localisation, and transfer of regulatory RNAs.

SEC-induced activation of ANXA7 GTPase suppresses prostate cancer metastasis

Annexin A7 (ANXA7) is a suppressor of tumorigenesis and metastasis in prostate cancer. Activated ANXA7 GTPase promotes prostate cancer cell apoptosis. However, the role and underlying mechanism of ANXA7 GTPase in prostate cancer metastasis have not been established. RKIP is a metastatic suppressor and downregulated in prostate cancer metastases. The binding of RKIP and its target proteins could inhibit the activation of its interactive partners. However, the effect of RKIP on ANXA7 GTPase activation is not clear. Here, we report that activation of ANXA7 GTPase by a small molecule SEC ((S)-ethyl 1-(3-(4-chlorophenoxy)-2-hydroxypropyl)-3- (4-methoxyphenyl)-1H-pyrazole-5-carboxylate) effectively inhibited prostate cancer metastasis. Mechanistically, activated ANXA7 promoted AMPK phosphorylation, leading to decreased mTORC1 activity, suppressed STAT3 nuclear translocation, and downregulation of pro-metastatic genes, including CCL2, APLN, and IL6ST. Conversely, RKIP interacted with ANXA7 and impaired activation of ANXA7 GTPase by SEC and its downstream signaling pathway. Notably, SEC treatment suppressed metastasis of prostate cancer cells in in vivo orthotopic analysis. Together, our findings provide a novel insight into how metastasis of prostate cancer with low RKIP expression is suppressed by SEC-induced activation of ANXA7 GTPase via the AMPK/mTORC1/STAT3 signaling pathway.

Characterization of urinary extracellular vesicle proteins in muscle-invasive bladder cancer

The mechanisms of bladder cancer progression are unknown, and new treatments and biomarkers are needed. Patient urinary extracellular vesicles (EVs) derive in part from bladder cancer cells and contain a specific protein cargo which may provide information about the disease. We conducted a proteomics study comparing EVs from the muscle-invasive bladder cancer (MIBC) cell line TCCSUP to EVs from normal urothelial line SVHUC. GO term analysis showed that TCCSUP EVs are enriched in proteins associated with the cell membrane, extracellular matrix, and inflammation and angiogenesis signaling pathways. Proteins characteristic of cancer EVs were further screened at the mRNA level in bladder cancer cell lines. In Western blots, three of six proteins examined showed greater than fifteenfold enrichment in patient urinary EVs compared to healthy volunteers (n = 6). Finally, we performed immunohistochemical staining of bladder tissue microarrays for three proteins of interest. One of them, transaldolase (TALDO1), is a nearly ubiquitous enzyme and normally thought to reside in the cytoplasm. To our surprise, nuclei were stained for transaldolase in 94% of MIBC tissue samples (n = 51). While cytoplasmic transaldolase was found in 89–90% of both normal urothelium (n = 79) and non-muscle-invasive samples (n = 71), the rate falls to 39% in MIBC samples (P < 0.001), and negative cytoplasmic staining was correlated with worse cancer-specific survival in MIBC patients (P = 0.008). The differential EV proteomics strategy reported here successfully identified a number of proteins associated with bladder cancer and points the way to future investigation.

Annexins - insights from knockout mice

Annexins are a highly conserved protein family that bind to phospholipids in a calcium (Ca2+) - dependent manner. Studies with purified annexins, as well as overexpression and knockdown approaches identified multiple functions predominantly linked to their dynamic and reversible membrane binding behavior. However, most annexins are found at multiple locations and interact with numerous proteins. Furthermore, similar membrane binding characteristics, overlapping localizations and shared interaction partners have complicated identification of their precise functions. To gain insight into annexin function in vivo, mouse models deficient of annexin A1 (AnxA1), A2, A4, A5, A6 and A7 have been generated. Interestingly, with the exception of one study, all mice strains lacking one or even two annexins are viable and develop normally. This suggested redundancy within annexins, but examining these knockout (KO) strains under stress conditions revealed striking phenotypes, identifying underlying mechanisms specific for individual annexins, often supporting Ca2+ homeostasis and membrane transport as central for annexin biology. Conversely, mice lacking AnxA1 or A2 show extracellular functions relevant in health and disease that appear independent of membrane trafficking or Ca2+ signaling. This review will summarize the mechanistic insights gained from studies utilizing mouse models lacking members of the annexin family.

Effect of annexin A7 suppression on the apoptosis of gastric cancer cells

Understanding the molecular mechanism of gastric cancer cell apoptosis is pivotal for the development of precise therapies targeting this disease. In the present study, we examined the effects of annexin A7 inhibition on the apoptosis of gastric cancer cells and the growth of tumour xenografts in vivo. Expression of annexin A7 in BGC823 cells was suppressed by small interference RNA, and cells apoptosis was assessed by flow cytometry. The mechanism by which annexin A7 mediates apoptosis in BGC823 cells was explored by determining the expression of key apoptosis regulators. In addition, by suppressing annexin A7 in BGC823 cells with small hairpin RNA, we studied the effects of annexin A7 inhibition on in vivo tumour growth. Our results showed that inhibiting annexin A7 expression induced more than fivefold increase in BGC823 cell apoptosis in vitro. This was in concord with a significant decrease of Bcl-2 expression and increases of Bax, Caspase-3, and Caspase-9. The activities of caspase-3 and caspase-9 were increased by 2.95 ± 0.18 and 3.70 ± 0.33 times, respectively, upon the annexin A7 downregulation in BGC823 cells. Importantly, suppressing annexin A7 showed the same apoptotic mechanism in vivo and significantly inhibited the growth of BGC823 xenografts in mice. These data suggest that annexin A7 likely protects gastric cells from apoptosis and targeting it may represent a valuable strategy in future therapeutic development.

ANXA7-GTPase as Tumor Suppressor: Mechanisms and Therapeutic Opportunities

Chromosomal abnormalities, including homozygous deletions and loss of heterozygosity at 10q, are commonly observed in most human tumors, including prostate, breast, and kidney cancers. The ANXA7-GTPase is a tumor suppressor, which is frequently inactivated by genomic alterations at 10q21. In the last few years, considerable amounts of data have accumulated describing inactivation of ANXA7-GTPase in a variety of human malignancies and demonstrating the tumor suppressor potential of ANXA7-GTPase. ANXA7-GTPase contains a calcium binding domain that classifies it as a member of the annexin family. The cancer-specific expression of ANXA7-GTPase, coupled with its importance in regulating cell death, cell motility, and invasion, makes it a useful diagnostic marker of cancer and a potential target for cancer treatment. Recently, emerging evidence suggests that ANXA7-GTPase is a critical factor associated with the metastatic state of several cancers and can be used as a risk biomarker for HER2 negative breast cancer patients. Cross talk between ANXA7, PTEN, and EGFR leads to constitutive activation of PI3K-AKT signaling, a central pathway of tumor cell survival and proliferation. This review focuses on the recent progress in understanding the tumor suppressor functions of ANXA7-GTPase emphasizing the role of this gene in Ca²⁺ metabolism, and exploring opportunities for function as an example of a calcium binding GTPase acting as a tumor suppressor and opportunities for ANXA7-GTPase gene cancer therapy.

Hepatocellular carcinoma mouse models: Hepatitis B virus-associated hepatocarcinogenesis and haploinsufficient tumor suppressor genes

The multifactorial and multistage pathogenesis of hepatocellular carcinoma (HCC) has fascinated a wide spectrum of scientists for decades. While a number of major risk factors have been identified, their mechanistic roles in hepatocarcinogenesis still need to be elucidated. Many tumor suppressor genes (TSGs) have been identified as being involved in HCC. These TSGs can be classified into two groups depending on the situation with respect to allelic mutation/loss in the tumors: the recessive TSGs with two required mutated alleles and the haploinsufficient TSGs with one required mutated allele. Hepatitis B virus (HBV) is one of the most important risk factors associated with HCC. Although mice cannot be infected with HBV due to the narrow host range of HBV and the lack of a proper receptor, one advantage of mouse models for HBV/HCC research is the numerous and powerful genetic tools that help investigate the phenotypic effects of viral proteins and allow the dissection of the dose-dependent action of TSGs. Here, we mainly focus on the application of mouse models in relation to HBV-associated HCC and on TSGs that act either in a recessive or in a haploinsufficient manner. Discoveries obtained using mouse models will have a great impact on HCC translational medicine.

In vivo and in vitro effect of hepatocarcinoma lymph node metastasis by upregulation of Annexin A7 and relevant mechanisms

We unveiled the association of Annexin A7 with vascular endothelial growth factor-C (VEGF-C) and the effect of upregulation of Annexin A7 in Hca-F and Hca-P cells on inhibiting hepatocarcinoma (HCC) lymph node metastasis (LNM) in vitro and in vivo. A total of 200 inbred 615 mice were randomly divided into four equal groups inoculated with Hca-F, Hca-P, FAnxa7-upregulated, and PAnxa7-upregulated cells, respectively. The primary tumor, popliteal, inguinal, and iliac lymph nodes were prepared for immunohistochemical (IHC) staining, real-time quantitative polymerase chain reaction (qRT-PCR) analysis, Western blot, and hematoxylin-eosin (H&E) staining. There was over 50 % increase both in the number of FAnxa7-upregulated and PAnxa7-upregulated cells migrated through the filter compared to their controls (FAnxa7-control, Hca-F and PAnxa7-control, Hca-P). However, no significant differences were noted in invasion ability between them (all P > 0.05). Tumor lymph vessels were significantly reduced in FAnxa7-upregulated and PAnxa7-upregulated tumors when compared with Hca-F and Hca-P tumors (all P < 0.05). Blood vessel density did not differ significantly between FAnxa7-upregulated and PAnxa7-upregulated tumors and Hca-F and Hca-P tumors. Enzyme-linked immunosorbent assay (ELISA) for VEGF-C showed that upregulating Annexin A7 decreased VEGF-C secretion in FAnxa7-upregulated and PAnxa7-upregulated cells (P < 0.05). The IHC staining result showed that the level of serum Annexin A7 was found to be statistically higher in all experimental groups than that in the control group (P < 0.05). The present results indicated that alterations in serum Annexin A7 expression may be of prognostic relevance in HCC lymphatic metastasis.

Ubiquitin-protein ligase E3C promotes glioma progression by mediating the ubiquitination and degrading of Annexin A7

The ubiquitin-protein ligase E3C (UBE3C) belongs to the E3 ligase enzyme family and implicates in the ubiquitin-proteasome pathway, thus regulates physiological and cancer-related processes. Here, we investigated the expression and roles of UBE3C in glioma. We demonstrated that UBE3C was overexpressed in glioma tissues and cell lines. Inhibition of UBE3C expression in glioma cells significantly decreased cell migration and invasion in vitro. Mechanistically, we disclosed that UBE3C physically interacted with and ubiquitinated tumor suppressor gene annexin A7 (ANXA7), resulting in ubiquitination and degradation of ANXA7. Our results also revealed that increased UBE3C expression was accompanied by a reduction in ANXA7 protein expression in glioma tissues, but not ANXA7 mRNA. Importantly, the inhibition of ANXA7 expression in gliomas cells with UBE3C interference could rescue the cell invasion. Clinically, UBE3C overexpression significantly correlated with high-grade tumors (p < 0.05), poor overall survival, and early tumor recurrence. Thus, our data reveal that high UBE3C expression contributes to glioma progression by ubiquitination and degradation of ANXA7, and thus presents a novel and promising target for glioma therapy.

Influence of annexin A7 on insulin sensitivity of cellular glucose uptake

Insulin sensitivity is decreased by prostaglandin E2 (PGE2), a major product of cyclooxygenase (COX). As shown in erythrocytes, PGE2 formation is inhibited by annexin A7. The present study defined the role of annexin A7 in glucose metabolism. Gene-targeted mice lacking annexin A7 (annexin7 (-/-)) were compared to wild-type mice (annexin7 (+/+)). The serum 6-Keto-prostaglandin-F1α (6-Keto-PGF1α) concentration was measured by ELISA and hepatic COX activity determined by an enzyme assay. Expression of COX-1, COX-2, prostaglandin E synthase, GLUT-4, and insulin receptor was determined by Western blotting. Glucose and insulin serum concentrations were analyzed following an intraperitoneal glucose load and glucose serum levels after intraperitoneal injection of insulin. Experiments were done without and with pretreatment of the mice with COX-inhibitor aspirin. The serum 6-Keto-PGF1α level and hepatic COX activity were significantly higher in annexin7 (-/-) than in annexin7 (+/+) mice. Hepatic COX-1 expression was higher in annexin7 (-/-) mice. Glucose tolerance was decreased in annexin7 (-/-) mice. Intraperitoneal insulin injection decreased the serum glucose level in both genotypes, an effect significantly less pronounced in annexin7 (-/-) mice. Glucose-induced insulin secretion was higher in annexin7 (-/-) mice. GLUT-4 expression in skeletal muscle from annexin7 (-/-) mice was reduced. Aspirin pretreatment lowered the increase in insulin concentration following glucose injection in both genotypes and virtually abrogated the differences in serum insulin between the genotypes. Aspirin pretreatment improved glucose tolerance in annexin7 (-/-) mice. In conclusion, annexin A7 influences insulin sensitivity of cellular glucose uptake and thus glucose tolerance. These effects depend on COX activity.

Diverse effects of ANXA7 and p53 on LNCaP prostate cancer cells are associated with regulation of SGK1 transcription and phosphorylation of the SGK1 target FOXO3A

Tumor suppressor function of the calcium/phospholipid-binding Annexin-A7 (ANXA7) has been shown in Anxa7-deficient mice and validated in human cancers. In the androgen-resistant prostate cancer cells, ANXA7 and p53 showed similar cytotoxicity levels. However, in the androgen-sensitive LNCaP, ANXA7 greatly exceeded the p53-induced cytotoxicity. We hypothesized that the p53 underperformance in LNCaP could be due to the involvement of p53-responsive SGK1 and FOXO3A. In this study, we show that p53 failed to match programmed cell death (PCD) and G1-arrest that were induced by ANXA7 in LNCaP. WT-ANXA7 preserved total FOXO3A expression with no hyperphosphorylation that could enable FOXO3A nuclear translocation and proapoptotic transcription. In contrast, in the p53-transfected LNCaP cells with maintained cell proliferation, the phosphorylated (but not total) FOXO3A fraction was increased implying a predominantly cytoplasmic localization and, subsequently, a lack of FOXO3A proapoptotic transcription. In addition, p53 reduced the expression of aberrant SGK1 protein form in LNCaP. Using Ingenuity Pathway Analysis and p53-signature genes, we elucidated the role of distinct SGK1/FOXO3A-associated regulation in p53 versus ANXA7 responses and proposed that aberrant SGK1 could affect reciprocal SGK1-FOXO3A-Akt regulation. Thus, the failure of the cell growth regulator p53 versus the phospholipid-binding ANXA7 could be potentially attributed to its diverse effects on SGK1-FOXO3A-Akt pathway in the PTEN-deficient LNCaP.

Annexin A7 deficiency potentiates cardiac NFAT activity promoting hypertrophic signaling

Annexin A7 (Anxa7) is a cytoskeletal protein interacting with Ca(2+) signaling which in turn is a crucial factor for cardiac remodeling following cardiac injury. The present study explored whether Anxa7 participates in the regulation of cardiac stress signaling. To this end, mice lacking functional Anxa7 (anxa7(-/-)) and wild-type mice (anxa7(+/+)) were investigated following pressure overload by transverse aortic constriction (TAC). In addition, HL-1 cardiomyocytes were silenced with Anxa7 siRNA and treated with isoproterenol. Transcript levels were determined by quantitative RT-PCR, transcriptional activity by luciferase reporter assay and protein abundance by Western blotting and confocal microscopy. As a result, TAC treatment increased the mRNA and protein levels of Anxa7 in wild-type mice. Moreover, TAC increased heart weight to body weight ratio and the cardiac mRNA levels of αSka, Nppb, Col1a1, Col3a1 and Rcan1, effects more pronounced in anxa7(-/-) mice than in anxa7(+/+) mice. Silencing of Anxa7 in HL-1 cardiomyocytes significantly increased nuclear localization of Nfatc1. Furthermore, Anxa7 silencing increased NFAT-dependent transcriptional activity as well as αSka, Nppb, and Rcan1 mRNA levels both, under control conditions and following β-adrenergic stimulation by isoproterenol. These observations point to an important role of annexin A7 in the regulation of cardiac NFAT activity and hypertrophic response following cardiac stress conditions.

Annexin A7 and its binding protein galectin-3 influence mouse hepatocellular carcinoma cell line in vitro

Lymph node metastasis is recognized as an important mode of liver cancer metastasis. Our previous study has built two hepatocarcinoma cell lines, Hca-F with high (75%) and Hca-P with low (25%) incidences of lymph node metastasis, and has indicated that annexin A7 is an important factor in the lymphatic metastasis of tumors. There is evidence that galectin-3 is the binding protein of annexin A7 and works in protein complexes. Our current study shows that both annexin A7 and galectin-3 express higher in Hca-F than Hca-P. Annexin A7 was successfully down-regulated in Hca-P by RNA interference, and this resulted in concomitant reduction of galactin 3 expression in annexin A7 down regulated compared to the control and N-control cells. Using CCK-8 assay, the expression level of annexin A7 and galectin-3 were found to have correlation with the proliferation ability; Transwell assay showed annexin A7 and galectin-3 are involved in cell migration and invasion regulation in mouse hepatocellular carcinoma cell lines, immunofluorescence assay indicate annexin A7 and galectin-3 were co-located annexin A7 and galectin-3 played roles in DNA damage and cell proliferation cycle checkpoint arrest pathway. Those phenomena indicated that annexin A7 influences lymphatic metastasis of tumors by interacting with galectin-3 through the regulation of tumor cell proliferation, attachment, migration and invasion.

Annexin A7 suppresses lymph node metastasis of hepatocarcinoma cells in a mouse model

Background

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death in China. This study investigated the effects of Annexin A7 (ANXA7) on the inhibition of HCC lymph node metastasis in a mouse model.

Methods

The stable knockup and knockdown of Annexin A7-expressing HCC cells using Annexin A7 cDNA and shRNA vectors, respectively, were injected into a mouse footpad to establish primary and metastatic tumors in mice. On the 14th, 21st, and 28th days after HCC cells inoculation, the mice were sacrificed for inspection of primary and secondary tumors and immunohistochemistry of Annexin A7 expression.

Results

The lymph node metastasis rate of the F_{ANXA7-control} group was 77%, and the lymph node metastasis rate of the F_ANXA7-down group was 100% (p < 0.05). In contrast, the lymph node metastasis rate of the P_ANXA7-up group was 0% and that of the P_{ANXA7-control} group was 36% (p < 0.05). Furthermore, immunohistochemistry experiments revealed that the subcellular localization of Annexin A7 protein in both primary and lymph node-metastasized tumors was mainly in the cytosol. In addition, the expression of the 47 kDa and 51 kDa isoforms of Annexin A7 protein changed during tumor progression.

Conclusion

This study indicated that Annexin A7 expression was able to inhibit HCC lymph node metastasis, whereas knockdown of Annexin A7 expression significantly induced HCC metastasis to local lymph nodes.

Potential role of annexin A7 in cancers

Annexin A7 (Anxa7) is a member of the multigene annexin superfamily of Ca(2+)-regulated and phospholipid-binding proteins. Accumulated evidence indicates that the deregulation, loss of heterozygosity (LOH) and subcellular localization of Anxa7 are associated with the occurrence, invasion, metastasis and progression of a variety of cancers. Anxa7 appears to have a tumor-suppression role in glioblastoma, glioblastoma multiforme (GBM), melanoma and prostate cancer (CaP) but, controversially and interestingly, Anxa7 also appears to promote the development and malignancies of liver cancer, gastric cancer (GC), nasopharyngeal carcinoma (NPC), colorectal cancer (CRC) and breast cancer (BC). The associations between Anxa7 and malignant tumors as well as potential mechanisms of action are summarized and discussed in current review. Anxa7 has potential for use as a biomarker for the diagnosis, treatment and prognosis of certain tumors.

Down-regulation of annexin A1 in the urothelium decreases cell survival after bacterial toxin exposure

PURPOSE

We examined the role of annexins in bladder urothelium. We characterized expression and distribution in normal bladders, biopsies from patients with bladder pain syndrome, cultured human urothelium and urothelial TEU-2 cells.

MATERIALS AND METHODS

Annexin expression in bladder layers was analyzed by quantitative reverse transcriptase-polymerase chain reaction and immunofluorescence. We assessed cell survival after exposure to the pore forming bacterial toxin streptolysin O by microscopy and alamarBlue® assay. Bladder dome biopsies were obtained from 8 asymptomatic controls and 28 patients with symptoms of bladder pain syndrome.

RESULTS

Annexin A1, A2, A5 and A6 were differentially distributed in bladder layers. Annexin A6 was abundant in detrusor smooth muscle and low in urothelium, while annexin A1 was the highest in urothelium. Annexin A2 was localized to the lateral membrane of umbrella cells but excluded from tight junctions. TEU-2 cell differentiation caused up-regulation of annexin A1 and A2 and down-regulation of annexin A6 mRNA. Mature urothelium dedifferentiation during culture caused the opposite effect, decreasing annexin A1 and increasing annexin A6. Annexin A2 influenced TEU-2 cell epithelial permeability. siRNA mediated knockdown of annexin A1 in TEU-2 cells caused significantly decreased cell survival after streptolysin O exposure. Annexin A1 was significantly reduced in biopsies from patients with bladder pain syndrome.

CONCLUSIONS

Several annexins are expressed in human bladder and TEU-2 cells, in which levels are regulated during urothelial differentiation. Annexin A1 down-regulation in patients with bladder pain syndrome might decrease cell survival and contribute to compromised urothelial function.

Expression and prognostic significance of gastric-specific annexin A10 in diffuse- and intestinal-type gastric carcinoma

BACKGROUND AND AIMS

Annexin A10 (ANXA10) and its liver-specific short isoform (ANXA10S) had tissue-restricted expression. The downregulation of ANXA10S is correlated with tumor progression and poor prognosis in hepatocellular carcinoma. The aim of the present study was to validate the tissue distribution and explore the role of the ANXA10 protein expression in gastric carcinoma.

METHODS

We examined the ANXA10 protein expression in human and animal tissues and 356 resected primary gastric carcinomas, using specific mouse and rabbit polyclonal antibodies, by immunohistochemical staining.

RESULTS

The ANXA10 protein is a nuclear protein specifically expressed in fetal and adult gastric mucosa and Brunner's gland across species, including humans, minipigs, woodchucks, and mice, and is commonly lost in gastric mucosa with intestinal metaplasia. The ANXA10 protein was expressed in 43.5% (155 cases) of gastric carcinomas; 74.2% (98/132) in the diffuse-type gastric carcinoma (DGC), 73.7% (28/38) in the mixed-type gastric carcinoma, and significantly lower in the intestinal-type gastric carcinoma (IGC) and indeterminate groups, 16.8% (28/167) and 5.3% (1/19), respectively (P<1×10(-8)). IGC with ANXA10 expression was correlated with a higher stage (P=0.049), particularly higher in stage IIIA/IIIB/IV IGC than lower-stage (IA/IB/II) tumors (P=0.005), but was not correlated with age, sex, and nodal status. In contrast, DGC with ANXA10 expression was associated with younger age, female patients, and importantly, lower tumor stage and lymph node metastasis (P=0.007, P=0.065, P=0.024, and P=0.0014, respectively). Moreover, DGC with ANXA10 expression had a better 5-year patient survival (P=0.0048), whereas IGC with ANXA10 expression had a lower 5-year survival (P=0.034).

CONCLUSIONS

The ANXA10 protein expression is a novel marker of gastric differentiation, and is differentially expressed in IGC and DGC, with opposite prognostic significance.

Role of multi-hnRNP nuclear complex in regulation of tumor suppressor ANXA7 in prostate cancer cells

Annexin-A7 (ANXA7) tumor suppressor role has been shown in various tumors, and ANXA7 expression has been particularly lost in androgen-resistant prostate cancers. In this study, we studied ANXA7 regulation in normal prostate versus androgen-sensitive and -resistant prostate cancer cells. Deletion mapping analysis showed lowest ANXA7-promoter activities in androgen-sensitive LNCaP prostate cancer cells. Genomatix analysis of ANXA7 promoter identified a cluster of steroid nuclear hormone receptor elements, including V$GREF (V$GRE.02/ARE.02). Gelshift analysis clearly indicated distinct nuclear protein occupancy at this ANXA7-promoter site (-1086/-890) in prostate cancer (LNCaP, DU145, and PC3) versus normal prostate (PrEC) cells. In matrix-assisted laser desorption time-of-flight mass spectrometry-based search for ANXA7 nuclear regulators, we identified several heterogeneous nuclear ribonucleoproteins (hnRNPs) (A1, A2/B1 and K) attached to the steroid-associated ANXA7-promoter site in the androgen-resistant PC3 prostate cancer cells with high ANXA7 gene copy number, but not in PrEC. The hnPNP role in ANXA7 regulation (that was validated by hnRNPA2/B1 antibody interference) resulted in multiple ANXA7 cDNA and protein products in PC3, but not in PrEC. Ingenuity pathways analysis showed plausible molecular paths between ANXA7 and the hnRNP-associated network in prostate cancer progression. Thus, a multi-hnRNP complex can be responsible for aberrant ANXA7 transcription and splicing, thereby affecting ANXA7 expression pattern and tumor suppressor function in prostate cancer.

Annexin-A7 protects normal prostate cells and induces distinct patterns of RB-associated cytotoxicity in androgen-sensitive and -resistant prostate cancer cells

The tumor suppressor role of annexin-A7 (ANXA7) was previously demonstrated by cancer susceptibility in Anxa7(+/-)-mice and by ANXA7 loss in human cancers, especially in hormone-resistant prostate tumors. To gain mechanistic insights into ANXA7 tumor suppression, we undertook an in vitro study in which we compared wild-type (WT)-ANXA7 and dominant-negative (DN)-ANXA7 effects to a conventional tumor suppressor p53 in prostate cancer cells with different androgen sensitivity. Unlike p53 (which caused cell growth arrest and apoptosis to a noticeable extent in benign PrEC), WT-ANXA7 demonstrated profound cytotoxicityin androgen-sensitive LNCaP as well as in the androgen-resistant DU145 and PC3 prostate cancer cells, but not in PrEC. In androgen-sensitive LNCaP, WT-ANXA7 decreased low-molecular-weight (LMW) AR protein forms and maintained higher retinoblastoma 1 (RB1)/phospho-RB1 ratio. In contrast, DN-ANXA7 (which lacks phosphatidylserine liposome aggregation properties) increased LMW-AR forms and hyperphosphorylated RB1 that was consistent with the lack of DN-ANXA7 cytotoxicity. According to the microarray-based Ingenuity Pathways Analysis, a major WT-ANXA7 effect in androgen-sensitive LNCaP constituted of upregulation of the RB1-binding transcription factor E2F1 along with its downstream proapoptotic targets such as ASK1 and ASPP2. These results suggested a reversal of the RBdependent repression of the proapoptotic E2F-mediated transcription. However, DN-ANXA7 increased RB1/2 (but not E2F1) expression and induced the proliferation-promoting ERK5, thereby maintaining the RB-dependent repression of E2F-mediated apoptosis in LNcaP. On the other hand, in androgen-resistant cells, WT-ANXA7 tumor suppressor effects involved PTEN and NFkB pathways. Thus, ANXA7 revived the RB-associated cell survival control and overcame androgen resistance and dysfunctional status of major tumor suppressors commonly mutated in prostate cancer. Published 2009 UICC.

Proteomic biomarkers for blast neurotrauma: targeting cerebral edema, inflammation, and neuronal death cascades

Proteomics for blast traumatic brain injury (bTBI) research represents an exciting new approach that can greatly help to address the complex pathology of this condition. Antibody-based platforms, antibody microarrays (AbMA), and reverse capture protein microarrays (RCPM) can complement the classical methods based on 2D gel electrophoresis and mass spectrometry (2DGE/MS). These new technologies can address problematic issues, such as sample complexity, sensitivity, quantitation, reproducibility, and analysis time, which are typically associated with 2DGE/MS. Combined with bioinformatics analysis and interpretation of primary microarray data, these methods will generate a new level of understanding about bTBI at the level of systems biology. As biological and clinical knowledge and the availability of these systems become more widely established, we expect that AbMA and RCPM will be used routinely in clinical diagnostics, and also for following therapeutic progress. At the technical level, we anticipate that these platforms will evolve to accommodate comprehensive, high-speed, label-free analysis on a human proteome-wide scale.

The annexins: spatial and temporal coordination of signaling events during cellular stress

Annexins are a family of structurally related, Ca2+-sensitive proteins that bind to negatively charged phospholipids and establish specific interactions with other lipids and lipid microdomains. They are present in all eukaryotic cells and share a common folding motif, the "annexin core", which incorporates Ca2+- and membrane-binding sites. Annexins participate in a variety of intracellular processes, ranging from the regulation of membrane dynamics to cell migration, proliferation, and apoptosis. Here we focus on the role of annexins in cellular signaling during stress. A chronic stress response triggers the activation of different intracellular pathways, resulting in profound changes in Ca2+ and pH homeostasis and the production of lipid second messengers. We review the latest data on how these changes are sensed by the annexins, which have the ability to simultaneously interact with specific lipid and protein moieties at the plasma membrane, contributing to stress adaptation via regulation of various signaling pathways.

Monosomy of chromosome 10 associated with dysregulation of epidermal growth factor signaling in glioblastomas

CONTEXT

Glioblastomas--uniformly fatal brain tumors--often have both monosomy of chromosome 10 and gains of the epidermal growth factor receptor (EGFR) gene locus on chromosome 7, an association for which the mechanism is poorly understood.

OBJECTIVES

To assess whether coselection of EGFR gains on 7p12 and monosomy 10 in glioblastomas promotes tumorigenic epidermal growth factor (EGF) signaling through loss of the annexin A7 (ANXA7) gene on 10q21.1-q21.2 and whether ANXA7 acts as a tumor suppressor gene by regulating EGFR in glioblastomas.

DESIGN, SETTING, AND PATIENTS

Multidimensional analysis of gene, coding sequence, promoter methylation, messenger RNA (mRNA) transcript, protein data for ANXA7 (and EGFR), and clinical patient data profiles of 543 high-grade gliomas from US medical centers and The Cancer Genome Atlas pilot project (made public 2006-2008; and unpublished, tumors collected 2001-2008). Functional analyses using LN229 and U87 glioblastoma cells.

MAIN OUTCOME MEASURES

Associations among ANXA7 gene dosage, coding sequence, promoter methylation, mRNA transcript, and protein expression. Effect of ANXA7 haploinsufficiency on EGFR signaling and patient survival. Joint effects of loss of ANXA7 and gain of EGFR expression on tumorigenesis.

RESULTS

Heterozygous ANXA7 gene deletion is associated with significant loss of ANXA7 mRNA transcript expression (P = 1 x 10(-15); linear regression) and a reduction (mean [SEM]) of 91.5% (2.3%) of ANXA7 protein expression compared with ANXA7 wild-type glioblastomas (P = .004; unpaired t test). ANXA7 loss of function stabilizes the EGFR protein (72%-744% increase in EGFR protein abundance) and augments EGFR transforming signaling in glioblastoma cells. ANXA7 haploinsufficiency doubles tumorigenic potential of glioblastoma cells, and combined ANXA7 knockdown and EGFR overexpression promotes tumorigenicity synergistically. The heterozygous loss of ANXA7 in approximately 75% of glioblastomas in the The Cancer Genome Atlas plus infrequency of ANXA7 mutation (approximately 6% of tumors) indicates its role as a haploinsufficiency gene. ANXA7 mRNA transcript expression, dichotomized at the median, associates with patient survival in 191 glioblastomas (log-rank P = .008; hazard ratio [HR], 0.667; 95% confidence interval [CI], 0.493-0.902; 46.9 vs 74.8 deaths/100 person-years for high vs low ANXA7 mRNA expression) and with a separate group of 180 high-grade gliomas (log-rank P = .00003; HR, 0.476; 95% CI, 0.333-0.680; 21.8 vs 50.0 deaths/100 person-years for high vs low ANXA7 mRNA expression). Deletion of the ANXA7 gene associates with poor patient survival in 189 glioblastomas (log-rank P = .042; HR, 0.686; 95% CI, 0.476-0.989; 54.0 vs 80.1 deaths/100 person-years for wild-type ANXA7 vs ANXA7 deletion).

CONCLUSION

Haploinsufficiency of the tumor suppressor ANXA7 due to monosomy of chromosome 10 provides a clinically relevant mechanism to augment EGFR signaling in glioblastomas beyond that resulting from amplification of the EGFR gene.

A network model of a cooperative genetic landscape in brain tumors

CONTEXT

Gliomas, particularly glioblastomas, are among the deadliest of human tumors. Gliomas emerge through the accumulation of recurrent chromosomal alterations, some of which target yet-to-be-discovered cancer genes. A persistent question concerns the biological basis for the coselection of these alterations during gliomagenesis.

OBJECTIVES

To describe a network model of a cooperative genetic landscape in gliomas and to evaluate its clinical relevance.

DESIGN, SETTING, AND PATIENTS

Multidimensional genomic profiles and clinical profiles of 501 patients with gliomas (45 tumors in an initial discovery set collected between 2001 and 2004 and 456 tumors in validation sets made public between 2006 and 2008) from multiple academic centers in the United States and The Cancer Genome Atlas Pilot Project (TCGA).

MAIN OUTCOME MEASURES

Identification of genes with coincident genetic alterations, correlated gene dosage and gene expression, and multiple functional interactions; association between those genes and patient survival.

RESULTS

Gliomas select for a nonrandom genetic landscape-a consistent pattern of chromosomal alterations-that involves altered regions ("territories") on chromosomes 1p, 7, 8q, 9p, 10, 12q, 13q, 19q, 20, and 22q (false-discovery rate-corrected P<.05). A network model shows that these territories harbor genes with putative synergistic, tumor-promoting relationships. The coalteration of the most interactive of these genes in glioblastoma is associated with unfavorable patient survival. A multigene risk scoring model based on 7 landscape genes (POLD2, CYCS, MYC, AKR1C3, YME1L1, ANXA7, and PDCD4) is associated with the duration of overall survival in 189 glioblastoma samples from TCGA (global log-rank P = .02 comparing 3 survival curves for patients with 0-2, 3-4, and 5-7 dosage-altered genes). Groups of patients with 0 to 2 (low-risk group) and 5 to 7 (high-risk group) dosage-altered genes experienced 49.24 and 79.56 deaths per 100 person-years (hazard ratio [HR], 1.63; 95% confidence interval [CI], 1.10-2.40; Cox regression model P = .02), respectively. These associations with survival are validated using gene expression data in 3 independent glioma studies, comprising 76 (global log-rank P = .003; 47.89 vs 15.13 deaths per 100 person-years for high risk vs low risk; Cox model HR, 3.04; 95% CI, 1.49-6.20; P = .002) and 70 (global log-rank P = .008; 83.43 vs 16.14 deaths per 100 person-years for high risk vs low risk; HR, 3.86; 95% CI, 1.59-9.35; P = .003) high-grade gliomas and 191 glioblastomas (global log-rank P = .002; 83.23 vs 34.16 deaths per 100 person-years for high risk vs low risk; HR, 2.27; 95% CI, 1.44-3.58; P<.001).

CONCLUSIONS

The alteration of multiple networking genes by recurrent chromosomal aberrations in gliomas deregulates critical signaling pathways through multiple, cooperative mechanisms. These mutations, which are likely due to nonrandom selection of a distinct genetic landscape during gliomagenesis, are associated with patient prognosis.

The role of annexins in tumour development and progression

The annexins are a super-family of closely related calcium and membrane-binding proteins. They have a diverse range of cellular functions that include vesicle trafficking, cell division, apoptosis, calcium signalling and growth regulation. Many studies have shown the annexins to be among the genes whose expression are consistently differentially altered in neoplasia. Some annexins show increased expression in specific types of tumours, while others show loss of expression. Mechanistic studies relating the changes in annexin expression to tumour cell function, particularly tumour invasion and metastasis, angiogenesis and drug resistance, are now also emerging. Changes in the expression of individual annexins are associated with particular types of tumour and hence the annexins may also be useful biomarkers in the clinic.

The significance of ANXA7 expression and its correlation with poor cellular differentiation and enhanced metastatic potential of gastric cancer

BACKGROUND

Annexin-A7 (ANXA7) exhibits biological and genetic properties expected of a tumor suppressor gene and may play a role in cancer progression. However, the ANXA7 expression in different histological subtypes of gastric adenocarcinomas and its correlation with invasive potentials has not been elucidated.

METHODS

Immunohistochemical staining of ANXA7 for 84 primary gastric adenocarcinomas was performed, and data was correlated with clinicopathological parameters of patients.

RESULTS

The ANXA7 expression was well correlated with the grade of differentiation of primary tumors. Its expression was detected in 100% (8/8), 64.9% (24/37), 66.7% (2/3), 31.9% (13/31), 0% (0/3), and 0% (0/2) of well-differentiated tubular, moderately-differentiated tubular, papillary, poorly differentiated, signet-ring cell, and mucinous adenocarcinoma, respectively. According to the Lauren's classification, the ANXA7 expression was higher in intestinal type than in diffuse type tumor (71.9% vs. 6.1%, P = 0.003). The loss of expression of ANXA7 expression was significantly related to distant metastasis (P = 0.04). However, there were no significant associations between the ANXA7 expression and survival of cancer patients (P = 0.159).

CONCLUSIONS

A striking correlation between ANXA7 expression and cell differentiation of gastric cancer was observed. The loss of expression of ANXA7 is associated with distant metastasis.