Annexin A2 silencing induces G2 arrest of non-small cell lung cancer cells through p53-dependent and -independent mechanisms

Label-based comparative proteomics of oral mucosal tissue to understand progression of precancerous lesions to oral squamous cell carcinoma

Introduction

Oral squamous cell carcinomas typically arise from precancerous lesions such as leukoplakia and erythroplakia. These lesions exhibit a range of histological changes from hyperplasia to dysplasia and carcinoma in situ, during their transformation to malignancy. The molecular mechanisms driving this multistage transition remain incompletely understood. To bridge this knowledge gap, our current study utilizes label based comparative proteomics to compare protein expression profiles across different histopathological grades of leukoplakia, erythroplakia, and oral squamous cell carcinoma samples, aiming to elucidate the molecular changes underlying lesion evolution.

Methodology

An 8-plex iTRAQ proteomics of 4 biological replicates from 8 clinical phenotypes of leukoplakia and erythroplakia, with hyperplasia, mild dysplasia, moderate dysplasia; along with phenotypes of well differentiated squamous cell carcinoma and moderately differentiated squamous cell carcinoma was carried out using the Orbitrap Fusion Lumos mass spectrometer. Raw files were processed with Maxquant, and statistical analysis across groups was conducted using MetaboAnalyst. Statistical tools such as ANOVA, PLS-DA VIP scoring, and correlation analysis were employed to identify differentially expressed proteins that had a linear expression variation across phenotypes of hyperplasia to cancer. Validation was done using Bioinformatic tools such as ClueGO + Cluepedia plugin in Cytoscape to extract functional annotations from gene ontology and pathway databases.

Results and discussion

A total of 2685 protein groups and 12,397 unique peptides were identified, and 61 proteins consistently exhibited valid reporter ion corrected intensities across all samples. Of these, 6 proteins showed linear varying expression across the analysed sample phenotypes. Collagen type VI alpha 2 chain (COL6A2), Fibrinogen β chain (FGB), and Vimentin (VIM) were found to have increased linear expression across pre-cancer phenotypes of leukoplakia to cancer, while Annexin A7 (ANXA7) was seen to be having a linear decreasing expression. Collagen type VI alpha 2 chain (COL6A2) and Annexin A2 (ANXA2) had increased linear expression across precancer phenotypes of erythroplakia to cancer. The mass spectrometry proteomics data have been deposited to the ProteomeXchanger Consortium via the PRIDE partner repository with the data set identifier PXD054190. These differentially expressed proteins mediate cancer progression mainly through extracellular exosome; collagen-containing extracellular matrix, hemostasis, platelet aggregation, and cell adhesion molecule binding.

Conclusion

Label-based proteomics is an ideal platform to study oral cancer progression. The differentially expressed proteins provide insights into the molecular mechanisms underlying the progression of oral premalignant lesions to malignant phenotypes. The study has translational value for early detection, risk stratification, and potential therapeutic targeting of oral premalignant lesions and in its prevention to malignant forms.

Tailored environments for directed mesenchymal stromal cell proliferation and differentiation using decellularized extracellular matrices in conjunction with substrate modulus

Decellularised extracellular matrix (dECM) produced by mesenchymal stromal cells (MSCs) is a promising biomaterial for improving the ex vivo expansion of MSCs. The dECMs are often deposited on high modulus surfaces such as tissue culture plastic or glass, and subsequent differentiation assays often bias towards osteogenesis. We tested the hypothesis that dECM deposited on substrates of varying modulus will produce cell culture environments that are tailored to promote the proliferation and/or lineage-specific differentiation of MSCs. dECM was produced on type I collagen-functionalised polyacrylamide hydrogels with discrete moduli (∼4, 10, and 40 kPa) or in a linear gradient of modulus that spans the same range, and the substrates were used as culture surfaces for MSCs. Fluorescence spectroscopy and mass spectrometry characterization revealed structural compositional changes in the dECM as a function of substrate modulus. Softer substrates (4 kPa) with dECM supported the largest number of MSCs after 7 days (∼1.6-fold increase compared to glass). Additionally, osteogenic differentiation was greatest on high modulus substrates (40 kPa and glass) with dECM. Nuclear translocation of YAP1 was observed on all surfaces with a modulus of 10 kPa or greater and may be a driver for the increased osteogenesis on the high modulus surfaces. These data demonstrate that dECM technology can be integrated with environmental parameters such as substrate modulus to improve/tailor MSC proliferation and differentiation during ex vivo culture. These results have potential impact in the improved expansion of MSCs for tailored therapeutic applications and in the development of advanced tissue engineering scaffolds. STATEMENT OF SIGNIFICANCE: Mesenchymal stromal cells (MSCs) are extensively used in tissue engineering and regenerative medicine due to their ability to proliferate, differentiate, and modulate the immune environment. Controlling MSC behavior is critical for advances in the field. Decellularised extracellular matrix (dECM) can maintain MSC properties in culture, increase their proliferation rate and capacity, and enhance their stimulated differentiation. Substrate stiffness is another key driver of cell function, and previous reports have primarily looked at dECM deposition and function on stiff substrates such as glass. Herein, we produce dECM on substrates of varying stiffness to create tailored environments that enhance desired MSC properties such as proliferation and differentiation. Additionally, we complete mechanistic studies including quantitative mass spec of the ECM to understand the biological function.

Promoter Hypomethylation Upregulates ANXA2 Expression in Pancreatic Cancer and is Associated with Poor Prognosis

Pancreatic cancer (PC) is one of the world's most aggressive and deadly cancers, owing to non-specific early clinical symptoms, late-stage diagnosis, and poor survival. Therefore, it is critical to identify specific biomarkers for its early diagnosis. Annexin A2 (ANXA2) is a calcium-dependent phospholipid-binding protein that has been reported to be upregulated in several cancer types, making it an emerging biomarker and potential cancer therapeutic target. However, the mechanism underlying the regulation of ANXA2 overexpression is still unclear. It is well established that genetic and epigenetic alterations may lead to widespread dysregulation of gene expression. Hence, in this study, we focused on exploring the regulatory mechanism of ANXA2 by investigating the transcriptional profile, methylation pattern, somatic mutation, and prognostic value of ANXA2 in PC using several bioinformatics databases. Our results revealed that the expression levels of ANXA2 were remarkably increased in PC tissues comparing to normal tissues. Furthermore, the high expression of ANXA2 was significantly related to the poor prognosis of PC patients. More importantly, we demonstrated for the first time that the ANXA2 promoter is hypomethylated in PC tissues compared to normal tissues which may result in ANXA2 overexpression in PC. However, more experimental research is required to corroborate our findings.

Annexin A2: A Double-Edged Sword in Pathogen Infection

Annexin A2 (ANXA2) is a multifunctional calcium- and phospholipid-binding protein that plays an important role in various cells. During pathogen infections, ANXA2 modulates the nuclear factor kappa-B (NF-κB) and cell apoptosis signaling pathways and guides the chemotaxis of inflammatory cells toward inflammation sites, thereby protecting the host organism through the modulation of the inflammatory response. In addition, ANXA2 can regulate immune responses, and in certain pathogen infections, it can interact with pathogen proteins to facilitate their invasion and proliferation. This review provides an overview of the research progress on how ANXA2 regulates pathogen infections.

Transcriptome-level discovery of survival-associated biomarkers and therapy targets in non-small-cell lung cancer

BACKGROUND AND PURPOSE

Survival rate of patients with lung cancer has increased by over 60% in the recent two decades. With longer survival, the identification of genes associated with survival has emerged as an issue of utmost importance to uncover the most promising biomarkers and therapeutic targets.

EXPERIMENTAL APPROACH

An integrated database was set up by combining multiple independent datasets with clinical data and transcriptome-level gene expression measurements. Univariate and multivariate survival analyses were performed to identify genes with higher expression levels linked to shorter survival. The strongest genes were filtered to include only those with known druggability.

KEY RESULTS

The entire database includes 2852 tumour specimens from 17 independent cohorts. Of these, 2227 have overall survival data and 1256 samples have progression-free survival time. The most significant genes associated with survival were MIF, UBC and B2M in lung adenocarcinoma and ANXA2, CSNK2A2 and KRT18 in squamous cell carcinoma. We also aimed to reveal the best druggable targets in non-smokers lung cancer. The three most promising hits in this cohort were MDK, THY1 and PADI2. The established lung cancer cohort was added to the Kaplan-Meier plotter (https://www.kmplot.com) enabling the validation of future gene expression-based biomarkers in both the present and yet unexamined subgroups of patients.

CONCLUSIONS AND IMPLICATIONS

In this study, we established a comprehensive database of transcriptome-level data for lung cancer. The database can be utilized to identify and rank the most promising biomarkers and therapeutic targets for different subtypes of lung cancer.

CD8+ T-Cell Signatures as Prognostic and Immunotherapy Response Predictors in Non-Small Cell Lung Cancer

Non-small cell lung carcinoma (NSCLC) represents the majority of lung cancer cases, comprising approximately 85 % of the total. The five-year survival rate for NSCLC patients remains discouragingly low. Recently, immunotherapy has emerged as a promising approach. Nevertheless, only a minority of patients experience considerable benefits from these treatments. This highlights the critical need for effective biomarkers that can predict both patient prognosis and response to immunotherapy. CD8+ T cells play a crucial role in cancer immunotherapy. Their presence within tumours is generally indicative of a favourable prognosis and increased efficacy of immunotherapy. This study was undertaken to identify and authenticate a novel biomarker signature based on CD8+ T-cell marker genes, to prognosticate therapeutic responses in individuals afflicted with NSCLC. This in-depth study was based on a total of 1,200 samples, which included four NSCLC specimens analysed through single-cell RNA sequencing (scRNA-seq), 1,000 NSCLC samples obtained from The Cancer Genome Atlas (TCGA) and 196 NSCLC specimens collected from the GSE37745 cohort. In patients with NSCLC, those presenting a favourable risk profile demonstrated notable elevations in specific immune cells while concurrently exhibiting reductions in other types. CD8+ T cells, with their established role in inducing apoptosis in cancer cells, have emerged as crucial predictors and modulators of treatment strategies for NSCLC patients. The combination of single-cell and bulk RNA sequencing has produced a biomarker signature, emphasizing the CD8+ T cells' crucial role in NSCLC prognosis and treatment.

Translational implications of targeting annexin A2: From membrane repair to muscular dystrophy, cardiovascular disease and cancer

Annexin A2 (A2) contributes to several key cellular functions and processes, including membrane repair. Effective repair prevents cell death and degeneration, especially in skeletal or cardiac muscle, epithelia, and endothelial cells. To maintain cell integrity after damage, mammalian cells activate multiple membrane repair mechanisms. One protein family that facilitates membrane repair processes are the Ca2+-regulated phospholipid-binding annexins. Annexin A2 facilitates repair in association with S100A10 and related S100 proteins by forming a plug and linking repair to other physiologic functions. Deficiency of annexin A2 enhances cellular degeneration, exacerbating muscular dystrophy and degeneration. Downstream of repair, annexin A2 links membrane with the cytoskeleton, calcium-dependent endocytosis, exocytosis, cell proliferation, transcription, and apoptosis to extracellular roles, including vascular fibrinolysis, and angiogenesis. These roles regulate cardiovascular disease progression. Finally, annexin A2 protects cancer cells from membrane damage due to immune cells or chemotherapy. Since these functions are regulated by post-translational modifications, they represent a therapeutic target for reducing the negative consequences of annexin A2 expression. Thus, connecting the roles of annexin A2 in repair to its other physiologic functions represents a new translational approach to treating muscular dystrophy and cardiovascular diseases without enhancing its pro-tumorigenic activities.

Interactions and conformational changes of annexin A2/p11 heterotetramer models on a membrane: a molecular dynamics study

Ca2+-dependent membrane-binding by the Annexin A2/p11 heterotetramer (A2t) plays an important role in various biological processes including fibrinogen activation and exocytosis in neuroendocrine cells. Two models where A2t associates with a single membrane surface were generated and used to perform molecular dynamics simulations. The first model mimics initial A2t-membrane binding through both Annexin A2 (A2) subunits of A2t (TS model) while the second model mimics A2t-binding through a single A2 subunit (OS model). Conformational changes were summarized using principal component analysis (PCA), simulation snapshots, and distance plots from the simulations. The full TS model, including the p11 dimer, fully associates with the membrane adopting a stable structure with little conformational variation as evidence by PCA. The unassociated subunits of the OS model moved toward the membrane. The molecular mechanics/Generalized-Born surface area (MMGBSA) method was applied to investigate the energetics of the models. The MMGBSA results demonstrated that R63 of p11 was the primary contributor to the p11-membrane interaction. The TS model results were both consistent with those found in the literature and provide novel insights about the specific residues driving the A2t-membrane interaction. Additionally, it represents the most complete model of A2t on the membrane surface available.Communicated by Ramaswamy H. Sarma.

Identification of Homoharringtonine as a potent inhibitor of glioblastoma cell proliferation and migration

We previously demonstrated that Annexin A2 (ANXA2) is a pivotal mediator of the pro-oncogenic features displayed by glioblastoma (GBM) tumors, the deadliest adult brain malignancies, being involved in cell stemness, proliferation and invasion, thus negatively impacting patient prognosis. Based on these results, we hypothesized that compounds able to revert ANXA2-dependent transcriptional features could be exploited as reliable treatments to inhibit GBM cell aggressiveness by hampering their proliferative and migratory potential. Transcriptional signatures obtained by the modulation of ANXA2 activity/levels were functionally mapped through the QUADrATiC bioinformatic tool for compound identification. Selected compounds were screened by cell proliferation and migration assays in primary GBM cells, and we identified Homoharringtonine (HHT) as a potent inhibitor of GBM cell motility and proliferation, without affecting their viability. A further molecular characterization of the effects displayed by HHT, confirmed its ability to inhibit a transcriptional program involved in cell migration and invasion. Moreover, we demonstrated that the multiple antitumoral effects displayed by HHT are correlated to the inhibition of a platelet derived growth factor receptor α (PDGFRα)-dependent intracellular signaling through the impairment of Signal transducer and activator of transcription 3 (STAT3) and Ras homolog family member A (RhoA) axes. Our results demonstrate that HHT may act as a potent inhibitor of cancer cell proliferation and invasion in GBM, by hampering multiple PDGFRα-dependent oncogenic signals transduced through the STAT3 and RhoA intracellular components, finally suggesting its potential transferability for achieving an effective impairment of peculiar GBM hallmarks.

Annexin A2 Improves the Osteogenic Differentiation of Mesenchymal Stem Cells Exposed to High-Glucose Conditions through Lessening the Senescence

Osteoporosis is frequently found in chronic diabetic patients, and it results in an increased risk of bone fractures occurring. The underlying mechanism of osteoporosis in diabetic patients is still largely unknown. Annexin A2 (ANXA2), a family of calcium-binding proteins, has been reported to be involved in many biological process including bone remodeling. This study aimed to investigate the role of ANXA2 in mesenchymal stem cells (MSCs) during in vitro osteoinduction under high-glucose concentrations. Osteogenic gene expression, calcium deposition, and cellular senescence were determined. The high-glucose conditions reduced the osteogenic differentiation potential of the MSCs along with the lower expression of ANXA2. Moreover, the high-glucose conditions increased the cellular senescence of the MSCs as determined by senescence-associated β-galactosidase staining and the expression of p16, p21, and p53 genes. The addition of recombinant ANXA2 could recover the glucose-induced deterioration of the osteogenic differentiation of the MSCs and ameliorate the glucose-induced cellular senescence of the MSCs. A Western blot analysis revealed an increase in p53 and phosphorylated p53 (Ser 15), which was decreased by recombinant ANXA2 in MSC osteoblastic differentiation under high-glucose conditions. Our study suggested that the alteration of ANXA2 in high-glucose conditions may be one of the plausible factors in the deterioration of bones in diabetic patients by triggering cellular senescence.

Pathobiological functions and clinical implications of annexin dysregulation in human cancers

Annexins are an extensive superfamily of structurally related calcium- and phospholipid-binding proteins, largely conserved and widely distributed among species. Twelve human annexins have been identified, referred to as Annexin A1-13 (A12 remains as of yet unassigned), whose genes are spread throughout the genome on eight different chromosomes. According to their distinct tissue distribution and subcellular localization, annexins have been functionally implicated in a variety of biological processes relevant to both physiological and pathological conditions. Dysregulation of annexin expression patterns and functions has been revealed as a common feature in multiple cancers, thereby emerging as potential biomarkers and molecular targets for clinical application. Nevertheless, translation of this knowledge to the clinic requires in-depth functional and mechanistic characterization of dysregulated annexins for each individual cancer type, since each protein exhibits varying expression levels and phenotypic specificity depending on the tumor types. This review specifically and thoroughly examines the current knowledge on annexin dysfunctions in carcinogenesis. Hence, available data on expression levels, mechanism of action and pathophysiological effects of Annexin A1-13 among different cancers will be dissected, also further discussing future perspectives for potential applications as biomarkers for early diagnosis, prognosis and molecular-targeted therapies. Special attention is devoted to head and neck cancers (HNC), a complex and heterogeneous group of aggressive malignancies, often lately diagnosed, with high mortality, and scarce therapeutic options.

A novel DNA aptamer targeting lung cancer stem cells exerts a therapeutic effect by binding and neutralizing Annexin A2

Cancer remains one of the leading causes of death worldwide. Cancer stem cells (CSCs) are the underlying reason for tumor recurrence, progression, and therapeutic resistance. Aptamers are synthetic single-stranded oligonucleotides that can specifically bind to various molecular targets. Here, we aim to develop an effective aptamer-based biomarker and therapeutic tool that targets CSCs for cancer therapy. We perform whole-cell-based systematic evolution of ligands by exponential enrichment (cell-SELEX) to screen DNA aptamers that specifically bound to lung CSCs, modeled by E-cadherin-silenced A549 cells. We develop a CSC-specific aptamer (AP-9R) specifically recognizing lung CSCs with high affinity and identify Annexin A2, a Ca²⁺-dependent membrane-binding protein, as its target. Annexin A2 expression was upregulated in lung CSCs and involved in cancer stemness. The expression of Annexin A2 was associated with signatures of stemness and metastasis, as well as poor clinical outcomes, in lung cancer in silico. Moreover, AP-9R decreased Annexin A2 expression and suppressed CSC properties in CSCs in vitro and in vivo. The present findings suggest that Annexin A2 is a CSC marker and regulator, and the CSC-specific aptamer AP-9R has potential theranostic applications for lung cancer.

Encephalomyocarditis Virus 2A Protein Inhibited Apoptosis by Interaction with Annexin A2 through JNK/c-Jun Pathway

Encephalomyocarditis virus can cause myocarditis and encephalitis in pigs and other mammals, thus posing a potential threat to public health safety. The 2A protein is an important virulence factor of EMCV. Previous studies have shown that the 2A protein may be related to the inhibition of apoptosis by virus, but its specific molecular mechanism is not clear. In this study, the 2A protein was expressed in Escherichia coli in order to find interacting cell proteins. A pull down assay, coupled with mass spectrometry, revealed that the 2A protein possibly interacted with annexin A2. Co-immunoprecipitation assays and confocal imaging analysis further demonstrated that the 2A protein interacted with annexin A2 in cells. In reducing the expression of annexin A2 by siRNA, the ability of the 2A protein to inhibit apoptosis was weakened and the proliferation of EMCV was slowed down. These results suggest that annexin A2 is closely related to the inhibition of apoptosis by 2A. Furthermore, both RT-PCR and western blot results showed that the 2A protein requires annexin A2 interaction to inhibit apoptosis via JNK/c-Jun pathway. Taken together, our data indicate that the 2A protein inhibits apoptosis by interacting with annexin A2 via the JNK/c-Jun pathway. These findings provide insight into the molecular pathogenesis underlying EMCV infection.

Tracing the evolution of aneuploid cancers by multiregional sequencing with CRUST

Clonal deconvolution of mutational landscapes is crucial to understand the evolutionary dynamics of cancer. Two limiting factors for clonal deconvolution that have remained unresolved are variation in purity and chromosomal copy number across different samples of the same tumor. We developed a semi-supervised algorithm that tracks variant calls through multi-sample spatiotemporal tumor data. While normalizing allele frequencies based on purity, it also adjusts for copy number changes at clonal deconvolution. Absent à priori copy number data, it renders in silico copy number estimations from bulk sequences. Using published and simulated tumor sequences, we reliably segregated clonal/subclonal variants even at a low sequencing depth (~50×). Given at least one pure tumor sample (>70% purity), we could normalize and deconvolve paired samples down to a purity of 40%. This renders a reliable clonal reconstruction well adapted to multi-regionally sampled solid tumors, which are often aneuploid and contaminated by non-cancer cells.

A monoclonal antibody against annexin A2 targets stem and progenitor cell fractions in tumors

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Development of a novel antibody (termed as mAb150) developed in our lab which targets annexin A2.

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Although there are earlier reports of another monoclonal antibody with the same target, the epitope recognized by mAb150 is novel.

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mAb150 is specifically recognized to target the achilles heel of cancer viz. cancer stem cells and progenitors that persist after treatments and potentially give rise to minimal residual disease.

The involvement of cancer stem cells (CSCs) in driving tumor dormancy and drug resistance is well established. Most therapeutic regimens however are ineffective in targeting these regenerative populations. We report the development and evaluation of a monoclonal antibody, mAb150, which targets the metastasis associated antigen, Annexin A2 (AnxA2) through recognition of a N-terminal epitope. Treatment with mAb150 potentiated re-entry of CSCs into the cell cycle that perturbed tumor dormancy and facilitated targeting of CSCs as was validated by in vitro and in vivo assays. Epigenetic potentiation further improved mAb150 efficacy in achieving total tumor regression by targeting regenerative populations to achieve tumor regression, specifically in high-grade serous ovarian adenocarcinoma.

Annexin A2 degradation contributes to dopaminergic cell apoptosis via regulating p53 in neurodegenerative conditions

BACKGROUND

P53 overexpression has been shown to involve in mitochondria-mediated dapaminergic neuron cell death in Parkinson's disease. However, the exactly molecular mechanisms responsible for the p53-dependent intrinsic cell death in neurodegenerative conditions remain unclearly. Annexin A2 is a multifunctional protein that negatively regulates p53 expression. The purpose of this study was to explore the mechanism of p53 dependent dopaminergic cell death and implication of Annexin A2 in cellular apoptosis in 1-methyl-4-phenylpyridinium (MPP+)-induced PC12 cells.

METHODS

The cell viability of neural PC12 cells was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltet-razolium bromide assay. Flow cytometry was used to evaluate the apoptosis and mitochondrial transmembrane potential of neural PC12 cells. The expression of p53 and Annexin A2 was analyzed by western blot assay.

RESULTS

The present study showed that the exposure of PC12 cells to neurotoxin MPP+ increased the expression levels of p53 and the discharge of mitochondrial transmembrane potential. Notably, Annexin A2 degradation was also observed in this cellular model of Parkinson's disease, in a time and dose-dependent manner. This expressing change of Annexin A2 was in direct proportion to the loss of cell viability of PC12 cells, and this expression pattern was in inverse proportion to p53 levels in this cellular model of Parkinson's disease.

CONCLUSION

These results indicated that Annexin A2 degradation plays a crucial role the degeneration of dapaminergic cells of Parkinson's disease, and Annexin A2 downregulation-mediated the cell death is closely associated with mitochondrial dysfunction via p53-dependent pathway; thus provide a novel therapeutic target for Parkinson's disease treatment.

A novel regulatory loop miR-101/ANXA2/EGR1 mediates malignant characteristics of liver cancer stem cells

Increasing evidence suggests that liver cancer stem cells (LCSCs) are the cellular determinants that promote tumor recurrence and metastases. Aberrantly expressed miRNAs were identified in LCSCs and found to play a significant role in modulating biological characteristics of LCSCs. In this study, we implemented miRNA microarrays in CD133+ LCSCs and found miR-101 expression was downregulated. Increasing miR-101 expression repressed the metastasis and tumorigenic potential in LCSCs. Further investigations showed that ANXA2 was a novel target of miR-101. And we revealed that ANXA2 plays a critical role in acceleration of cell cycle and enhancing the migration and invasion abilities of LCSCs. Elevated ANXA2 increased activation of extracellular signal-regulated kinase (ERK) which regulated SOX2 and cell cycle-related kinases. Moreover, ERK phosphorylation inhibited the expression of early growth response 1 (EGR1) which in turn restrained the transcription of miR-101. In vivo experiments, overexpression of miR-101 produced potent inhibitory effects on the growth of LCSCs xenograft tumors as well as ANXA2 knockdown. Taken together, our findings suggest a novel regulatory loop miR-101/ANXA2/EGR1 in LCSCs and may serve as potential therapeutic targets in liver cancer.

Advances in cancer treatment: a new therapeutic target, Annexin A2

Annexin A2 (ANXA2) is a calcium regulated phospholipid-binding protein. It is expressed in some tumor cells, endothelial cells, macrophages, and mononuclear cells, affecting cell survival and mediating interactions between intercellular and extracellular microenvironment. Aberrant expression of ANXA2 can be used as a potential predictive factor, diagnostic biomarker and therapeutic target in cancer therapy. Investigators used various technologies to target ANXA2 in a preclinical model of human cancers and demonstrated encouraging results. In this review article, we discuss the diagnosis and prognosis latent capacity of ANXA2 in progressive cancers, focus on the exploration of restorative interventions targeting ANXA2 in cancer treatment. Further, we comment on a promising candidate therapy that is conceivable for clinical translation.

Overexpression of Annexin A2 promotes proliferation by forming a Glypican 1/c-Myc positive feedback loop: prognostic significance in human glioma

In order to set up a reliable prediction system for the tumor grade and prognosis in glioma patients, we clarify the complicated crosstalk of Annexin A2 (ANXA2) with Glypican 1 (GPC1) and demonstrate whether combined indexes of ANXA2 and GPC1 could improve the prognostic evaluation for glioma patients. We found that ANXA2-induced glioma cell proliferation in a c-Myc-dependent manner. ANXA2 increased the expression of GPC1 via c-Myc and the upregulated GPC1 further promoted the c-Myc level, forming a positive feedback loop, which eventually led to enhanced proliferation of glioma cells. Both mRNA and protein levels of ANXA2 were upregulated in glioma tissues and coincided with the overexpression of GPC1. Besides, we utilized tissue microarrays (TMAs) and immunohistochemistry to demonstrate that glioma patients with both high expression of ANXA2 and GPC1 tended to have higher rate of tumor recurrence and shorter overall survival (OS). In conclusion, the overexpression of ANXA2 promotes proliferation of glioma cells by forming a GPC1/c-Myc positive feedback loop, and ANXA2 together with its downstream target GPC1 could be a potential "combination biomarker" for predicting prognosis of glioma patients.

Clinical significance of Annexin A2 expression in oral squamous cell carcinoma and its influence on cell proliferation, migration and invasion

Oral squamous cell carcinoma (OSCC) is the most common malignant epithelial neoplasm of the head and neck, with poorer prognosis. There is lack of specific targets for diagnosis and treatment of OSCC at present. Annexin A2 (ANXA2) is involved in cell angiogenesis, invasion, proliferation and metastasis. In this study, the significance and effect of ANXA2 on OSCC and OSCC cells were explored from the clinical and basic study. First, ANXA2 expression in OSCC tissues and adjacent non-cancer tissues of 124 patients were detected, and the correlation between ANXA2 expression and clinical parameters were analyzed. The results found that ANXA2 was highly expressed in OSCC tissues, and was associated with the TNM stage, tumor differentiation, lymph node metastasis and poor survival of OSCC patients. The expression of ANXA2 in OSCC cells were higher than the normal oral cells. And knockdown of ANXA2 by transfecting ANXA2-siRNA could suppress the proliferation, migration, and invasion abilities of OSCC cells. Overall, ANXA2 expression is correlated with poor survival of OSCC patients, and silencing of ANXA2 suppress the proliferation, migration and invasion of OSCC cells.

RNF115-mediated ubiquitination of p53 regulates lung adenocarcinoma proliferation

Lung adenocarcinoma (LAC) represents approximately 40% of all lung cancer cases and is the leading cause of cancer-associated mortality worldwide. Although combined treatment, including radiotherapy, chemotherapy, surgical treatment and immunotherapy, has been used in treating LAC, the five-year survival rate of patients with LAC has not significantly improved. Therefore, it is vital for cancer research to investigate novel prognostic markers and new targets for molecular targeted therapy in LAC. TP53 is an important tumor suppressor gene and is frequently inactivated in lung cancer, thus upregulation or activation of p53 may be a novel targeted therapy for LAC. The present study found that RNF115 mediates ubiquitination of p53 and predicts poor prognosis of patients with LAC. Functionally, it was demonstrated that disruption of RNF115 significantly inhibited cell viability in vitro through inducing G1 phase arrest of LAC cells, which reduced tumor growth in an xenograft model. Taken together, these results suggest that RNF115 could be a novel prognostic biomarker and the RNF115-p53 axis may be a potential target for LAC therapy.

Comparative proteogenomics profiling of non-small and small lung carcinoma cell lines using mass spectrometry

Background

Evidences indicated that non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC) might originate from the same cell type, which however ended up to be two different subtypes of lung carcinoma, requiring different therapeutic regimens. We aimed to identify the differences between these two subtypes of lung cancer by using integrated proteome and genome approaches.

Methods and Materials

Two representative cell lines for each lung cancer subtype were comparatively analysed by quantitative proteomics, and their corresponding transcriptomics data were obtained from the Gene Expression Omnibus database. The integrated analyses of proteogenomic data were performed to determine key differentially expressed proteins that were positively correlated between proteomic and transcriptomic data.

Result

The proteomics analysis revealed 147 differentially expressed proteins between SCLC and NSCLC from a total of 3,970 identified proteins. Combined with available transcriptomics data, we further confirmed 14 differentially expressed proteins including six known and eight new lung cancer related proteins that were positively correlated with their transcriptomics data. These proteins are mainly involved in cell migration, proliferation, and invasion.

Conclusion

The proteogenomic data on both NSCLC and SCLC cell lines presented in this manuscript is complementary to existing genomic and proteomic data related to lung cancers and will be crucial for a systems biology-level understanding of the molecular mechanism of lung cancers. The raw mass spectrometry data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD015270.

Proteins inform survival-based differences in patients with glioblastoma

BACKGROUND

Improving the care of patients with glioblastoma (GB) requires accurate and reliable predictors of patient prognosis. Unfortunately, while protein markers are an effective readout of cellular function, proteomics has been underutilized in GB prognostic marker discovery.

METHODS

For this study, GB patients were prospectively recruited and proteomics discovery using liquid chromatography-mass spectrometry analysis (LC-MS/MS) was performed for 27 patients including 13 short-term survivors (STS) (≤10 months) and 14 long-term survivors (LTS) (≥18 months).

RESULTS

Proteomics discovery identified 11 941 peptides in 2495 unique proteins, with 469 proteins exhibiting significant dysregulation when comparing STS to LTS. We verified the differential abundance of 67 out of these 469 proteins in a small previously published independent dataset. Proteins involved in axon guidance were upregulated in STS compared to LTS, while those involved in p53 signaling were upregulated in LTS. We also assessed the correlation between LS MS/MS data with RNAseq data from the same discovery patients and found a low correlation between protein abundance and mRNA expression. Finally, using LC-MS/MS on a set of 18 samples from 6 patients, we quantified the intratumoral heterogeneity of more than 2256 proteins in the multisample dataset.

CONCLUSIONS

These proteomic datasets and noted protein variations present a beneficial resource for better predicting patient outcome and investigating potential therapeutic targets.

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.

High expression of Annexin A2 is associated with DNA repair, metabolic alteration, and worse survival in pancreatic ductal adenocarcinoma

BACKGROUND

Annexin A2 (ANXA2) is a known driver of cancer progression. We investigated what mechanism associates with ANXA2 high expression and its survival impact using a bioinformatic approach in pancreatic ductal adenocarcinoma.

METHODS

Primary pancreatic tumor (n = 185) cohort in The Cancer Genome Atlas and Gene set enrichment analysis were used.

RESULTS

There were no significant associations between ANXA2 expression and clinicopathologic features of the patients investigated. The ANXA2 high tumors enriched some of the known downstream signaling, such as NF-κB (P = .028) and tumor necrosis factor (P = .044) pathways, whereas others, such as angiogenesis or epithelial-mesenchymal transition, were not associated. ANXA2 high expression tumors enriched DNA repair-related gene sets (DNA repair; P = .011, p53 pathway; P = .036) and cell proliferation-related gene sets (MYC targets; P = .041). In addition, new association with metabolism related gene sets, such as glycolysis (P = .016), nucleic acid metabolism (P = .001), and pyrimidine metabolism (P = .004) were identified in the ANXA2 high group. Patients with high ANXA2 expression demonstrated significantly worse disease-free survival (P = .001) and overall survival (P = .014), with high ANXA2 being an independent risk factor.

CONCLUSION

High ANXA2 expression was associated with NF-κB and tumor necrosis factor signaling, DNA repair, cell proliferation, and metabolic alteration and worse prognosis in pancreatic ductal adenocarcinoma.

Anti-pancreatic tumor efficacy of a Listeria-based, Annexin A2-targeting immunotherapy in combination with anti-PD-1 antibodies

BACKGROUND

Immune checkpoint inhibitors are not effective for pancreatic ductal adenocarcinoma (PDAC) as single agents. Vaccine therapy may sensitize PDACs to checkpoint inhibitor treatments. Annexin A2 (ANXA2) is a pro-metastasis protein, previously identified as a relevant PDAC antigen that is expressed by a GM-CSF-secreting allogenic whole pancreatic tumor cell vaccine (GVAX) to induce an anti-ANXA2 antibody response in patients with PDAC. We hypothesized that an ANXA2-targeting vaccine approach not only provokes an immune response but also mounts anti-tumor effects.

METHODS

We developed a Listeria-based, ANXA2-targeting cancer immunotherapy (Lm-ANXA2) and investigated its effectiveness within two murine models of PDAC.

RESULTS

We show that Lm-ANXA2 prolonged the survival in a transplant model of mouse PDACs. More importantly, priming with the Lm-ANXA2 treatment prior to administration of anti-PD-1 antibodies increased cure rates in the implanted PDAC model and resulted in objective tumor responses and prolonged survival in the genetically engineered spontaneous PDAC model. In tumors treated with Lm-ANXA2 followed by anti-PD-1 antibody, the T cells specific to ANXA2 had significantly increased INFγ expression.

CONCLUSIONS

For the first time, a listeria vaccine-based immunotherapy was shown to be able to induce a tumor antigen-specific T cell response within the tumor microenvironment of a "cold" tumor such as PDAC and sensitize the tumor to checkpoint inhibitor therapy. Moreover, this combination immunotherapy led to objective tumor responses and survival benefit in the mice with spontaneously developed PDAC tumors. Therefore, our study supports developing Lm-ANXA2 as a therapeutic agent in combination with anti-PD-1 antibody for PDAC treatment.

ANXA2 Silencing Inhibits Proliferation, Invasion, and Migration in Gastric Cancer Cells

Annexin A2 (ANXA2) has been well known to associate with the progress of malignant tumor. However, the biological behavior of ANXA2 in gastric cancer (GC) remains unclear. We made a hypothesis in transcriptome level from TCGA datasets. Then, we used immunohistochemical staining to quantify the expression level of ANXA2 protein in GC tissues compared with adjacent tissues. Quantitative real-time PCR and western blot were used for analyzing ANXA2 expression in human GC (SGC-7901, MKN-45, BGC-823, and AGS) cell lines. We investigated the effect of a lentivirus-mediated knock-down of ANXA2 on the proliferation, invasion and migration of gastric cancer AGS cells. Cell proliferation was examined by MTT and colony formation tests. Cell apoptosis and cycle were measured by flow cytometry. Migration and invasion were detected by transwell assay. We found that high expression of ANXA2 can increase the mobility of cancer cells from TCGA datasets. ANXA2 was upregulated in GC tissues compared with adjacent tissues. AGS cell line displayed significantly higher expression of ANXA2 among the four GC cell lines. In addition, ANXA2 silencing led to a weakened ability of proliferation, invasion, and migration in GC cells; targeting of ANXA2 may be a potential therapeutic strategy for GC patients.

Autoencoder Based Feature Selection Method for Classification of Anticancer Drug Response

Anticancer drug responses can be varied for individual patients. This difference is mainly caused by genetic reasons, like mutations and RNA expression. Thus, these genetic features are often used to construct classification models to predict the drug response. This research focuses on the feature selection issue for the classification models. Because of the vast dimensions of the feature space for predicting drug response, the autoencoder network was first built, and a subset of inputs with the important contribution was selected. Then by using the Boruta algorithm, a further small set of features was determined for the random forest, which was used to predict drug response. Two datasets, GDSC and CCLE, were used to illustrate the efficiency of the proposed method.

Annexin A2 Silencing Inhibits Proliferation and Epithelial-to-mesenchymal Transition through p53-Dependent Pathway in NSCLCs

Annexin A2 has been involved in cancer cell adhesion, invasion and metastasis. However, the exact function and mechanism of Annexin A2 in tumor progression of NSCLCs have not been elucidated. In this study, we showed that Annexin A2 was evidently overexpressed in human NSCLCs cell lines and NSCLCs tissues. Clinicopathologic analysis showed that Annexin A2 expression was significantly correlated with clinical stage, and lymph node metastasis. Kaplan-Meier analysis revealed that patients with high Annexin A2 expression had poorer overall survival rates than those with low Annexin A2 expression. Moreover, we found that knockdown of Annexin A2 significantly suppressed cell proliferation and invasion of NSCLCs cells. Mechanistically, our studies showed that knockdown of Annexin A2 increased the expression of p53, which in turn, induced cell cycle G2 arrest and inhibited epithelial-to-mesenchymal transition (EMT). Taken together, these data suggest that Annexin A2 plays an important role in NSCLCs progression, which could serve as a potential prognosis marker and a novel therapeutic target for NSCLCs.

Stomatin-like protein 2 regulates survivin expression in non-small cell lung cancer cells through β-catenin signaling pathway

The overexpression of stomatin-like protein-2 (SLP-2) is commonly observed in non-small cell lung cancer (NSCLC) cells. In the present study, we transfected a number of NSCLC cells with an SLP-2 shRNA-expressing vector (AdSLP2i) and examined its possible effects on cell growth and apoptosis. We found that suppression of SLP-2 expression inhibited cell growth, and that the apoptosis induced by SLP-2 suppression was correlated with decreased survivin protein expression. Moreover, the reduced survivin expression was found to be associated with reduced β-catenin nuclear localization and appeared not to be modulated through the AKT signaling pathway. By using immunoprecipitation and proteomics to analyze protein-protein interactions in A549 cells with SLP-2 overexpression, we found that annexin A2 interacted with SLP-2 and β-catenin directly. Our data further suggested that the knockdown of SLP-2 gene affected the SLP-2/Annexin A2/β-catenin cascade formation, reduced the translocation of cytoplasmic β-catenin into nucleus, and downregulated downstream target genes. The results presented in this study, together with our previous findings, suggest that SLP-2 promotes NSCLC cell proliferation by enhancing survivin expression mediated via β-catenin pathway.

Annexin A2-mediated cancer progression and therapeutic resistance in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a head and neck cancer with poor clinical outcomes and insufficient treatments in Southeast Asian populations. Although concurrent chemoradiotherapy has improved recovery rates of patients, poor overall survival and low efficacy are still critical problems. To improve the therapeutic efficacy, we focused on a tumor-associated protein called Annexin A2 (ANXA2). This review summarizes the mechanisms by which ANXA2 promotes cancer progression (e.g., proliferation, migration, the epithelial-mesenchymal transition, invasion, and cancer stem cell formation) and therapeutic resistance (e.g., radiotherapy, chemotherapy, and immunotherapy). These mechanisms gave us a deeper understanding of the molecular aspects of cancer progression, and further provided us with a great opportunity to overcome therapeutic resistance of NPC and other cancers with high ANXA2 expression by developing this prospective ANXA2-targeted therapy.

Identification of natural compounds targeting Annexin A2 with an anti-cancer effect

Annexin A2, a multifunctional tumor associated protein, promotes nuclear factor-kappa B (NF-κB) activation by interacting with NF-κB p50 subunit and facilitating its nuclear translocation. Here we demonstrated that two ginsenosides Rg5 (G-Rg5) and Rk1 (G-Rk1), with similar structure, directly bound to Annexin A2 by molecular docking and cellular thermal shift assay. Both Rg5 and Rk1 inhibited the interaction between Annexin A2 and NF-κB p50 subunit, their translocation to nuclear and NF-κB activation. Inhibition of NF-κB by these two ginsenosides decreased the expression of inhibitor of apoptosis proteins (IAPs), leading to caspase activation and apoptosis. Over expression of K302A Annexin A2, a mutant version of Annexin A2, which fails to interact with G-Rg5 and G-Rk1, effectively reduced the NF-κB inhibitory effect and apoptosis induced by G-Rg5 and G-Rk1. In addition, the knockdown of Annexin A2 largely enhanced NF-κB activation and apoptosis induced by the two molecules, indicating that the effects of G-Rg5 and G-Rk1 on NF-κB were mainly mediated by Annexin A2. Taken together, this study for the first time demonstrated that G-Rg5 and G-Rk1 inhibit tumor cell growth by targeting Annexin A2 and NF-κB pathway, and G-Rg5 and G-Rk1 might be promising natural compounds for targeted cancer therapy.

Annexin 2A sustains glioblastoma cell dissemination and proliferation

Glioblastoma (GBM) is the most devastating tumor of the brain, characterized by an almost inevitable tendency to recur after intensive treatments and a fatal prognosis. Indeed, despite recent technical improvements in GBM surgery, the complete eradication of cancer cell disseminated outside the tumor mass still remains a crucial issue for glioma patients management. In this context, Annexin 2A (ANXA2) is a phospholipid-binding protein expressed in a variety of cell types, whose expression has been recently associated with cell dissemination and metastasis in many cancer types, thus making ANXA2 an attractive putative regulator of cell invasion also in GBM.

Here we show that ANXA2 is over-expressed in GBM and positively correlates with tumor aggressiveness and patient survival. In particular, we associate the expression of ANXA2 to a mesenchymal and metastatic phenotype of GBM tumors. Moreover, we functionally characterized the effects exerted by ANXA2 inhibition in primary GBM cultures, demonstrating its ability to sustain cell migration, matrix invasion, cytoskeletal remodeling and proliferation. Finally, we were able to generate an ANXA2-dependent gene signature with a significant prognostic potential in different cohorts of solid tumor patients, including GBM.

In conclusion, we demonstrate that ANXA2 acts at multiple levels in determining the disseminating and aggressive behaviour of GBM cells, thus proving its potential as a possible target and strong prognostic factor in the future management of GBM patients.

siRNA directed against Annexin II receptor inhibits HeLa cell proliferation, migration and invasion and induces apoptosis via suppressing ERK1/2 and Akt signaling pathways

Annexin II receptor (AXIIR) was originally identified as a cell surface receptor for Annexin II and was shown to be involved in the development and progression of multiple cancers, but little was known about its role in cervical cancer. The aim of our study was to investigate the role and the plausible molecular mechanism of AXIIR in regulating apoptosis, invasion and migration of cervical cancer cells. siRNA targeting AXIIR was chemical synthesized and transfected into HeLa cells which with non-specific siRNA tranfection used as a negative control. Cell proliferation, cell migration, cell invasion and cell apoptosis assay were measured by CCK-8, wound healing assay, Transwell invasion assay and flow cytometry, respectively. Tumor-related protein and signaling pathway were also measured by real-time quantitative PCR and western blot assay to investigate the molecular mechanism of AXIIR involved in regulating HeLa cells. Our data showed that AXIIR siRNA significantly inhibited HeLa cell viability and induced cell apoptosis by increases in Caspase-3/-8/-9 mRNA and protein expression, and inhibit HeLa cell migration and invasion by decreased MMP-2/-9 mRNA and protein expression. AXIIR siRNA could also significantly down-regulate Akt, p-Akt, ERK1/2 and p-ERK1/2 expression. In conclusion, AXIIR is of great importance for regulatingcell viability, migration, invasion and apoptosis in vitro. The molecular mechanism of AXIIR might be the activation of PI3K/Akt and ERK1/2 signaling pathway, indicating a critical regulator function of AXIIR in tumorigenic responses of cervical cancer.

Cancer-associated fibroblasts promote epithelial-mesenchymal transition and EGFR-TKI resistance of non-small cell lung cancers via HGF/IGF-1/ANXA2 signaling

The involvement of the tumor stromal cells in acquired resistance of non-small cell lung cancers (NSCLCs) to tyrosine kinase inhibitors (TKIs) has previously been reported, but the precise mechanism remains unclear. In the present study, we investigated the role and mechanism underlying Cancer-associated fibroblasts (CAFs) in TKI resistance of NSCLCs. In vitro and in vivo experiments showed that HCC827 and PC9 cells, non-small cell lung cancer cells with EGFR-activating mutations, became resistant to the EGFR-TKI gefitinib when cultured with CAFs isolated from NSCLC tissues. Moreover, we showed that CAFs could induce epithelial-mesenchymal transition (EMT) phenotype of HCC827 and PC9 cells, with an associated change in the expression of epithelial to mesenchymal transition markers. Using proteomics-based method, we identified that CAFs significantly increased the expression of the Annexin A2 (ANXA2). More importantly, knockdown of ANXA2 completely reversed EMT phenotype and gefitinib resistance induced by CAFs. Furthermore, we found that CAFs increased the expression and phosphorylation of ANXA2 by secretion of growth factors HGF and IGF-1 and by activation of the corresponding receptors c-met and IGF-1R. Dual inhibition of HGF/c-met and IGF-1/IGF-1R pathways could significantly suppress ANXA2, and markedly reduced CAFs-induced EMT and gefitinib resistance. Taken together, these findings indicate that CAFs promote EGFR-TKIs resistance through HGF/IGF-1/ANXA2/EMT signaling and may be an ideal therapeutic target in NSCLCs with EGFR-activating mutations.

Stromal Annexin A2 expression is predictive of decreased survival in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDA) is renowned for high rates of metastasis and poor survival. Its notoriously dense fibrotic stroma contributes to chemoresistance. Stromal signaling in PDA is recognized for its multiple roles in regulating tumor invasion and metastasis. However, no stromal biomarker which can predict survival in PDA exists. Annexin A2 (AnxA2) was formerly identified as a metastasis-associated protein in PDA and tumoral overexpression is associated with poor survival. In this study, we examined AnxA2 expression in the tumor microenvironment in a preclinical model of PDA which suggests its role in tumor colonization. We injected wild-type (KPC) and AnxA2 knockout (KPCA) pancreatic cells into C57BL/GJ (B6) and AnxA2 knockout (KO) mice using the hemi-spleen model and observed their survival. We performed quantitative immunohistochemistry examining stromal AnxA2 expression in 56 patients who had surgically resected PDA and correlated expression with clinical outcomes. B6 mice injected with KPC cells demonstrated decreased median survival compared to those injected with KPCA cells (90 days vs. not reached, p < 0.0001) whereas there was no survival difference in the AnxA2 KO mice (p = 0.63). In patient specimens, we found that high stromal AnxA2 expression (≥80th percentile) was associated with significantly reduced disease-free survival (p = 0.002) and overall survival (p < 0.001). Using multivariate Cox models, there were no significant associations between other clinical covariates apart from high stromal AnxA2 expression. This study highlights the role that stromal AnxA2 expression plays as a prognostic marker in PDA and its potential as a predictive biomarker for survival outcomes in PDA.

Annexin A2 is an independent prognostic biomarker for evaluating the malignant progression of laryngeal cancer

Due to the lack of a definite diagnosis, a frequent recurrence rate and resistance to chemotherapy or radiotherapy, the clinical outcome for patients with advanced laryngeal cancer has not improved over the last decade. Annexin A2 is associated with the invasion and metastasis of cancer cells. In the present study, it was demonstrated using differential proteomics analysis that Annexin A2 is highly expressed in laryngeal carcinoma tissues and this was confirmed using immunohistochemistry, which demonstrated that the expression of Annexin A2 in laryngeal carcinoma tissues was significantly higher than in healthy adjacent tissue. In addition, its potential predictive value in the prognosis of patients with laryngeal carcinoma was evaluated. The results demonstrated that Annexin A2 expression was significantly associated with tumor size, lymph node metastasis, distant metastasis and clinical stage. In addition, higher Annexin A2 expression was associated with a poor prognosis of patients with laryngeal cancer. Thus, the results of the present study indicate that Annexin A2 expression is an independent prognostic biomarker for evaluating the malignant progression of laryngeal cancer.

[Omics technologies in diagnostics of lung adenocarcinoma]

To date lung adenocarcinoma (LAC) is the most common type of lung cancer. Numerous studies on LAC biology resulted in identification of crucial mutations in protooncogenes and activating neoplastic transformation pathways. Therapeutic approaches that significantly increase the survival rate of patients with LAC of different etiology have been developed and introduced into clinical practice. However, the main problem in the treatment of LAC is early diagnosis, taking into account both factors and mechanisms responsible in tumor initiation and progression. Identification of a wide biomarker repertoire with high specificity and reliability of detection appears to be a solution to this problem. In this context, proteins with differential expression in normal and pathological condition, suitable for detection in biological fluids are the most promising biomarkers. In this review we have analyzed literature data on studies aimed at search of LAC biomarkers. The major attention has been paid to protein biomarkers as the most promising and convenient subject of clinical diagnosis. The review also summarizes existing knowledge on posttranslational modifications, splice variants, isoforms, as well as model systems and transcriptome changes in LAC.

Annexin A2 (ANXA2) interacts with nonstructural protein 1 and promotes the replication of highly pathogenic H5N1 avian influenza virus

BACKGROUND

Non-structural protein 1 (NS1) is a multifunctional protein and a crucial regulatory factor in the replication and pathogenesis of avian influenza virus (AIV). Studies have shown that NS1 can interact with a variety of host proteins to modulate the viral life cycle. We previously generated a monoclonal antibody against NS1 protein; In the current research study, using this antibody, we immunoprecipitated host proteins that interact with NS1 to better understand the roles played by NS1 in communications between virus and host.

RESULTS

Co-immunoprecipitation experiments identified annexin A2 (ANXA2) as a target molecule interacting with NS1. Results from confocal laser scanning microscopy indicated that NS1 co-localized with ANXA2 in the cell cytoplasm. Overexpression of ANXA2 significantly increased the titer of H5N1 subtype HPAIV, whereas siRNA-mediated knockdown of ANXA2 markedly inhibited the expression of viral proteins and reduced the progeny virus titer.

CONCLUSIONS

Our results indicate that ANXA2 interacts with NS1 and ANXA2 expression increases HPAIV replication.

Annexin A2 contributes to cisplatin resistance by activation of JNK-p53 pathway in non-small cell lung cancer cells

BACKGROUND

Development of resistance to therapy continues to be a serious clinical problem in lung cancer management. We previously identified that Annexin A2 is significantly up-regulated in cisplatin-resistant non-small cell lung cancer (NSCLC) A549/DDP cells. However, the exact function and molecular mechanism of Annexin A2 in cisplatin resistance of NSCLCs has not been determined.

METHODS

Western blot and qRT-PCR were performed to analyze the protein and mRNA level of indicated molecules, respectively. Immunohistochemistry was performed to analyze the expression of Annexin A2 in NSCLC tissue samples. MTS assay, Colony formation assays, AnnexinV/PI apoptosis assay, Luciferase Reporter Assay, Chromatin-immunoprecipitation, and nude mice xenograft assay were used to visualize the function of Annexin A2 on cisplatin resistance.

RESULTS

Our results demonstrated that knockdown of Annexin A2 increased cisplatin sensitivity of cisplatin-resistant A549/DDP cells both in vitro and in vivo, whereas overexpression of Annexin A2 increased cisplatin resistance of A549, H460 and H1650 cells. Moreover, we found that Annexin A2 enhanced cisplatin resistance via inhibition of cisplatin-induced cell apoptosis. Our studies showed that Annexin A2 suppressed the expression of p53 through activation of JNK/c-Jun signaling, which in turn resulted in a decrease in the expression of p53-regulated apoptotic genes p21, GADD45 and BAX, as well as p53-dependent cell apoptosis. Furthermore, we found that in NSCLC cases that Annexin A2 is highly expressed; it is positively correlated with a poor prognosis, as well as correlated with short disease-free survival for patients who received chemotherapy after surgery.

CONCLUSIONS

These data suggested that Annexin A2 induces cisplatin resistance of NSCLCs via regulation of JNK/c-Jun/p53 signaling, and provided an evidence that blockade of Annexin A2 could serve as a novel therapeutic approach for overcoming drug resistance in NSCLCs.

Determination of Genes Related to Uveitis by Utilization of the Random Walk with Restart Algorithm on a Protein-Protein Interaction Network

Uveitis, defined as inflammation of the uveal tract, may cause blindness in both young and middle-aged people. Approximately 10–15% of blindness in the West is caused by uveitis. Therefore, a comprehensive investigation to determine the disease pathogenesis is urgent, as it will thus be possible to design effective treatments. Identification of the disease genes that cause uveitis is an important requirement to achieve this goal. To begin to answer this question, in this study, a computational method was proposed to identify novel uveitis-related genes. This method was executed on a large protein–protein interaction network and employed a popular ranking algorithm, the Random Walk with Restart (RWR) algorithm. To improve the utility of the method, a permutation test and a procedure for selecting core genes were added, which helped to exclude false discoveries and select the most important candidate genes. The five-fold cross-validation was adopted to evaluate the method, yielding the average F1-measure of 0.189. In addition, we compared our method with a classic GBA-based method to further indicate its utility. Based on our method, 56 putative genes were chosen for further assessment. We have determined that several of these genes (e.g., CCL4, Jun, and MMP9) are likely to be important for the pathogenesis of uveitis.

Integrative Diffusion-Weighted Imaging and Radiogenomic Network Analysis of Glioblastoma multiforme

In the past, changes of the Apparent Diffusion Coefficient in glioblastoma multiforme have been shown to be related to specific genes and described as being associated with survival. The purpose of this study was to investigate diffusion imaging parameters in combination with genome-wide expression data in order to obtain a comprehensive characterisation of the transcriptomic changes indicated by diffusion imaging parameters. Diffusion-weighted imaging, molecular and clinical data were collected prospectively in 21 patients. Before surgery, MRI diffusion metrics such as axial (AD), radial (RD), mean diffusivity (MD) and fractional anisotropy (FA) were assessed from the contrast enhancing tumour regions. Intraoperatively, tissue was sampled from the same areas using neuronavigation. Transcriptional data of the tissue samples was analysed by Weighted Gene Co-Expression Network Analysis (WGCNA) thus classifying genes into modules based on their network-based affiliations. Subsequent Gene Set Enrichment Analysis (GSEA) identified biological functions or pathways of the expression modules. Network analysis showed a strong association between FA and epithelial-to-mesenchymal-transition (EMT) pathway activation. Also, patients with high FA had a worse clinical outcome. MD correlated with neural function related genes and patients with high MD values had longer overall survival. In conclusion, FA and MD are associated with distinct molecular patterns and opposed clinical outcomes.

Integrative Modeling Reveals Annexin A2-mediated Epigenetic Control of Mesenchymal Glioblastoma

Glioblastomas are characterized by transcriptionally distinct subtypes, but despite possible clinical relevance, their regulation remains poorly understood. The commonly used molecular classification systems for GBM all identify a subtype with high expression of mesenchymal marker transcripts, strongly associated with invasive growth. We used a comprehensive data-driven network modeling technique (augmented sparse inverse covariance selection, aSICS) to define separate genomic, epigenetic, and transcriptional regulators of glioblastoma subtypes. Our model identified Annexin A2 (ANXA2) as a novel methylation-controlled positive regulator of the mesenchymal subtype. Subsequent evaluation in two independent cohorts established ANXA2 expression as a prognostic factor that is dependent on ANXA2 promoter methylation. ANXA2 knockdown in primary glioblastoma stem cell-like cultures suppressed known mesenchymal master regulators, and abrogated cell proliferation and invasion. Our results place ANXA2 at the apex of a regulatory cascade that determines glioblastoma mesenchymal transformation and validate aSICS as a general methodology to uncover regulators of cancer subtypes.

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Glioblastoma, a form of brain cancer, is characterised by distinct molecular subtypes: proneural, classical and mesenchymal.

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We used a comprehensive data-driven strategy, aSICS, to elucidate the cellular mechanisms behind the subtypes.

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Epigenetic control of Annexin A2 (ANXA2) was predicted and confirmed to determine the invasive mesenchymal subtype.

Most cancers have distinct and clinically relevant transcriptional subtypes, but the underlying cellular mechanism behind such subtypes is often hard to resolve. We show that joint analysis across several layers of genomics data can uncover subtype regulators with good accuracy. Our method is applied to the brain cancer glioblastoma multiforme (GBM), revealing that the invasive mesenchymal subtype is driven by epigenetic modulation of the expression of Annexin A2 (ANXA2). Our analysis adds significantly to our understanding of brain cancer subtypes and open for new potential treatment options. The proposed computational technique can be applied to other cancers as well.

Annexin A2 and S100A10 are independent predictors of serous ovarian cancer outcome

Annexin A2, a calcium phospholipid binding protein, has been shown to play an important role in ovarian cancer metastasis. This study examined whether annexin A2 and S100A10 can be used as prognostic markers in serous ovarian cancer. ANXA2 and S100A10 gene expressions were assessed in publicly available ovarian cancer data sets and annexin A2 and S100A10 protein expressions were assessed by immunohistochemistry in a uniform cohort of stage III serous ovarian cancers (n = 109). Kaplan-Meier and Cox regression analyses were performed to assess the relationship between annexin A2 or S100A10 messenger RNA (mRNA) and protein expressions with clinical outcome. High ANXA2 mRNA levels in stage III serous ovarian cancers were associated with reduced progression-free survival (PFS; P = 0.023) and overall survival (OS; P = 0.0038), whereas high S100A10 mRNA levels predicted reduced OS (P = 0.0019). Using The Cancer Genome Atlas data sets, ANXA2 but not S100A10 expression was associated with higher clinical stage (P = 0.005), whereas both ANXA2 and S100A10 expressions were associated with the mesenchymal molecular subtype (P < 0.0001). Kaplan-Meier and Cox regression analyses showed that high stromal annexin A2 immunostaining was significantly associated with reduced PFS (P = 0.013) and OS (P = 0.044). Moreover, high cytoplasmic S100A10 staining was significantly associated with reduced OS (P = 0.027). Multivariate Cox regression analysis showed stromal annexin A2 (P = 0.009) and cytoplasmic S100A10 (P = 0.016) levels to be independent predictors of OS. Patients with high stromal annexin A2 and high cytoplasmic S100A10 expressions had a 3.4-fold increased risk of progression (P = 0.02) and 7.9-fold risk of ovarian cancer death (P = 0.04). Our findings indicate that together annexin A2 and S100A10 expressions are powerful predictors of serous ovarian cancer outcome.

RNAi-mediated silencing of Anxa2 inhibits breast cancer cell proliferation by downregulating cyclin D1 in STAT3-dependent pathway

Although the upregulated expression of Anxa2 has been implicated in carcinogenesis, cancer progression, and poor prognosis of cancer patients, the detailed molecular mechanisms involved in these processes remain unclear. In this study, we investigated the effect of Anxa2 downregulation with small interference RNA on breast cancer proliferation. To explore molecular mechanisms underlying Anxa2-mediated cancer cell proliferation. We analyzed cell cycle distribution and signaling pathways using semi-quantitative real-time PCR and Western blotting. Anxa2 depletion in breast cancer cells significantly inhibited cell proliferation by decelerating cell cycle progression. The retarded G1-to-S phase transition in Anxa2-silenced cells was attributed to the decreased levels of cyclin D1, which is a crucial promoting factor for cell proliferation because it regulates G1-to-S phase transition during cell cycle progression. We provided evidence that Anxa2 regulates epidermal growth factor-induced phosphorylation of STAT3. The reduced expression of phosphorylated STAT3 is the main factor responsible for decreased cyclin D1 levels in Anxa2-silenced breast cancer cells. Our results revealed the direct relationship between Anxa2 and activation of STAT3, a key transcription factor that plays a pivotal role in regulating breast cancer proliferation and survival. This study provides novel insights into the functions of Anxa2 as a critical molecule in cellular signal transduction and significantly improves our understanding of the mechanism through which Anxa2 regulates cell cycle and cancer cell proliferation.

Association of annexin A2 with cancer development (Review)

Annexin A2 (ANXA2) is a well-known calcium-dependent phospholipid binding protein widely distributed in the nucleus, cytoplasm and extracellular surface of various eukaryotic cells. It has been recognized as a pleiotropic protein affecting a wide range of molecular and cellular processes. Dysregulation and abnormal expression of ANXA2 are linked to a large number of prevalent diseases, including autoimmune and neurodegenerative disease, antiphospholipid syndrome, inflammation, diabetes mellitus and a series of cancers. Accumulating data suggest that ANXA2 is aberrantly expressed in a wide spectrum of cancers, and exerts profound effects on tumor cell adhesion, proliferation, apoptosis, invasion and metastasis as well as tumor neovascularization via different modes of action. However, despite significant research, our knowledge of the mechanism by which ANXA2 participates in cancer development remains fragmented. The present review systematically summarizes the effects of ANXA2 on tumor progression, in an attempt to gain an improved understanding of the underlying mechanisms and to provide a potential effective target for cancer therapy.

Annexin A2 plays a critical role in epithelial ovarian cancer

PURPOSE

This study aimed at investigating the potential role and prognostic significance of Annexin A2 in human epithelial ovarian cancer (EOC).

METHODS

Western blot was used to evaluate the expression of Annexin A2 in nine fresh EOC tissues, and immunohistochemical analysis was performed on formalin-fixed paraffin-embedded sections of 119 cases of ovarian cancers. Then, we used Fisher exact test to analyze the correlation between Annexin A2 and clinicopathological parameters. Starvation refeeding was used to detect the alteration of Annexin A2 in HO8910 cell cycle.

RESULTS

Annexin A2 was overexpressed in carcinoma tissues compared with normal tissue, and the expression levels gradually increased from G1 to G3. Moreover, the staining of tissue microarray was consistent with the result we got from western blot, increasing from G1 to G3 gradually, and it was related to the Figo stage (P = 0.005), histologic grade (P = 0.002), ascite (P < 0.001), malignant tumor cells (P < 0.001), residual tumor size (P = 0.044), Ki-67 (P = 0.003). Kaplan-Meier analysis revealed that high Annexin A2 expression was significantly associated with poor prognoses of the patients (P < 0.001). Multivariate analysis demonstrated that Annexin A2 was an independent prognostic indicator for overall survival. Starvation refeeding indicated that Annexin A2 was related to EOC cell proliferation.

CONCLUSIONS

We could hypothesize that Annexin A2 acted a critical role in EOC cell proliferation, and may be used as a potential and novel therapeutic target for EOC. These data suggest that Annexin A2 may promote the progression of EOC and be a therapeutic target for EOC therapy.

RNAi-mediated knockdown of the c-jun gene sensitizes radioresistant human nasopharyngeal carcinoma cell line CNE-2R to radiation

This study aimed to investigate the effect of RNA interference (RNAi)-mediated downregulation of the expression of the c-jun gene (a proto-oncogene) on the radiosensitivity of a radioresistant human nasopharyngeal carcinoma cell line (CNE-2R) and to validate its potential as an anticancer target. A lentiviral vector with c-jun small hairpin RNA (shRNA) was constructed and transfected into CNE-2R cells. The gene silencing efficiency of these recombinants was confirmed by RT-PCR and western blotting. Radiosensitivity, cell proliferation, cell cycle profile and apoptosis were assessed using colony formation assay, CCK-8 assay and flow cytometry, respectively. The lentiviral shRNA efficiently knocked down the expression of c-jun at both the mRNA and protein levels (P<0.05). c-jun-downregulated CNE-2R cells exhibited significantly decreased cell proliferation and enhanced radiosensitivity compared to the control group (P<0.05), and the effects were likely due to G2/M phase arrest and enhanced cell apoptosis. These data provide evidence that c-jun may be involved in the radioresistance of nasopharyngeal carcinoma (NPC) and knockdown of the c-jun gene may be a potential strategy to enhance the radiation sensitivity of NPC.

MicroRNA-206 functions as a pleiotropic modulator of cell proliferation, invasion and lymphangiogenesis in pancreatic adenocarcinoma by targeting ANXA2 and KRAS genes

Recent advances in cancer biology have emerged important roles for microRNAs (miRNAs) in regulating tumor responses. However, their function in mediating intercellular communication within the tumor microenvironment is thus far poorly explored. Here, we found miR-206 to be abrogated in human pancreatic ductal adenocarcinoma (PDAC) specimens and cell lines. We show that miR-206 directly targets the oncogenes KRAS and annexin a2 (ANXA2), thereby acting as tumor suppressor in PDAC cells by blocking cell cycle progression, cell proliferation, migration and invasion. Importantly, we identified miR-206 as a negative regulator of oncogenic KRAS-induced nuclear factor-κB transcriptional activity, resulting in a concomitant reduction of the expression and secretion of pro-angiogenic and pro-inflammatory factors including the cytokine interleukin-8, the chemokines (C-X-C motif) ligand 1 and (C–C motif) ligand 2, and the granulocyte macrophage colony-stimulating factor. We further show that miR-206 abrogates the expression and secretion of the potent pro-lymphangiogenic factor vascular endothelial growth factor C in pancreatic cancer cells through an NF-κB-independent mechanism. By using in vitro and in vivo approaches, we reveal that re-expression of miR-206 in PDAC cells is sufficient to inhibit tumor blood and lymphatic vessel formation, thus leading to a significant delay of tumor growth and progression. Taken together, our study sheds light onto the role of miR-206 as a pleiotropic modulator of different hallmarks of cancer, and as such raising the intriguing possibility that miR-206 may be an attractive candidate for miRNA-based anticancer therapies.