Astrocyte Elevated Gene-1 (AEG-1) Contributes to Non-thyroidal Illness Syndrome (NTIS) Associated with Hepatocellular Carcinoma (HCC)

Spatial transcriptomics unravels palmitoylation and zonation-dependent gene regulation by AEG-1 in mouse liver

Obesity-induced metabolic dysfunction-associated steatohepatitis (MASH) leads to hepatocellular carcinoma (HCC). Astrocyte-elevated gene-1/Metadherin (AEG-1/MTDH) plays a key role in promoting MASH and HCC. AEG-1 is palmitoylated at residue cysteine 75 (Cys75) and a knock-in mouse representing mutated Cys75 to serine (AEG-1-C75S) showed activation of MASH- and HCC-promoting gene signature when compared to wild-type littermates (AEG-1-WT). The liver consists of three zones, periportal, mid-lobular, and pericentral, and zone-specific dysregulated gene expression impairs metabolic homeostasis in the liver, contributing to MASH and HCC. Here, to elucidate how palmitoylation influences AEG-1-mediated gene regulation in regard to hepatic zonation, we performed spatial transcriptomics (ST) in the livers of AEG-1-WT and AEG-1-C75S littermates. ST identified six different clusters in livers and using zone- and cell-type-specific markers we attributed specific zones and cell types to specific clusters. Ingenuity Pathway Analysis (IPA) of differentially expressed genes in each cluster unraveled activation of pro-inflammatory and MASH- and HCC-promoting pathways, mainly in periportal and pericentral hepatocytes, in AEG-1-C75S liver compared to AEG-1-WT. Interestingly, in AEG-1-C75S liver, the mid-lobular zone exhibited widespread inhibition of xenobiotic metabolism pathways and inhibition of PXR/RXR and LXR/RXR activation, versus AEG-1-WT. In conclusion, AEG-1-C75S mutant exhibited zone-specific differential gene expression, which might contribute to metabolic dysfunction and dysregulated drug metabolism leading to MASH and HCC.

Metadherin-driven promotion of cancer stem cell phenotypes and its effect on immunity in hepatocellular carcinoma

In this editorial we provide commentary on the article published by Wang et al, featured in the recent issue of the World Journal of Gastroenterology in 2024. We focus on the metadherin (MTDH), also known as astrocyte elevated gene-1 or lysine rich CEACAM1, and its effects on cancer stem cells (CSCs) and immunity in hepatocellular carcinoma (HCC). HCC is the most common primary liver cancer and one of the leading causes of cancer-related deaths worldwide. Most HCC cases develop in the context of liver cirrhosis. Among the pivotal mechanisms of carcinogenesis are gene mutations, dysregulation of diverse signaling pathways, epigenetic alterations, hepatitis B virus-induced hepatocarcinogenesis, chronic inflammation, impact of tumor microenvironment, oxidative stress. Over the years, extensive research has been conducted on the MTDH role in various tumor pathologies, such as lung, breast, ovarian, gastric, hepatocellular, colorectal, renal carcinoma, neuroblastoma, melanoma, and leukemias. Specifically, its involvement in tumor development processes including transformation, apoptosis evasion, angiogenesis, invasion, and metastasis via multiple signaling pathways. It has been demonstrated that knockdown or knockout of MTDH disrupt tumor development and metastasis. In addition, numerous reports have been carried out regarding the MTDH influence on HCC, demonstrating its role as a predictor of poor prognosis, aggressive tumor phenotypes prone to metastasis and recurrence, and exhibiting significant potential for therapy resistance. Finally, more studies finely investigated the influence of MTDH on CSCs. The CSCs are a small subpopulation of tumor cells that sharing traits with normal stem cells like self-renewal and differentiation abilities, alongside a high plasticity that alters their phenotype. Beyond their presumed role in tumor initiation, they can drive also disease relapse, metastasis, and resistance to chemo and radiotherapy.

Expression patterns of AEG-1 in the normal brain

Astrocyte elevated gene-1 (AEG-1) is a well-known oncogene implicated in various types of human cancers, including brain tumors. Recently, AEG-1 has also been reported to play pivotal roles in glioma-associated neurodegeneration and neurodegenerative diseases like Parkinson's disease and amyotrophic lateral sclerosis. However, the normal physiological functions and expression patterns of AEG-1 in the brain are not well understood. In this study, we investigated the expression patterns of AEG-1 in the normal mouse brain and found that AEG-1 is widely expressed in neurons and neuronal precursor cells, but little in glial cells. We observed differential expression levels of AEG-1 in various brain regions, and its expression was mainly localized in the cell body of neurons rather than the nucleus. Additionally, AEG-1 was expressed in the cytoplasm of Purkinje cells in both the mouse and human cerebellum, suggesting its potential role in this brain region. These findings suggest that AEG-1 may have important functions in normal brain physiology and warrant further investigation. Our results may also shed light on the differential expression patterns of AEG-1 in normal and pathological brains, providing insights into its roles in various neurological disorders.

Astrocyte Elevated Gene-1 Cys75 S-Palmitoylation by ZDHHC6 Regulates Its Biological Activity

Nonalcoholic fatty liver disease is a major risk factor for hepatocellular carcinoma (HCC). Astrocyte elevated gene-1/Metadherin (AEG-1/MTDH) augments lipid accumulation (steatosis), inflammation, and tumorigenesis, thereby promoting the whole spectrum of this disease process. Targeting AEG-1 is a potential interventional strategy for nonalcoholic steatohepatitis (NASH) and HCC. Thus, proper understanding of the regulation of this molecule is essential. We found that AEG-1 is palmitoylated at residue cysteine 75 (Cys75). Mutation of Cys75 to serine (Ser) completely abolished AEG-1 palmitoylation. We identified ZDHHC6 as a palmitoyltransferase catalyzing the process in HEK293T cells. To obtain insight into how palmitoylation regulates AEG-1 function, we generated knock-in mice by CRISPR/Cas9 in which Cys75 of AEG-1 was mutated to Ser (AEG-1-C75S). No developmental or anatomical abnormality was observed between AEG-1-wild type (AEG-1-WT) and AEG-1-C75S littermates. However, global gene expression analysis by RNA-sequencing unraveled that signaling pathways and upstream regulators, which contribute to cell proliferation, motility, inflammation, angiogenesis, and lipid accumulation, were activated in AEG-1-C75S hepatocytes compared to AEG-1-WT. These findings suggest that AEG-1-C75S functions as dominant positive and that palmitoylation restricts oncogenic and NASH-promoting functions of AEG-1. We thus identify a previously unknown regulatory mechanism of AEG-1, which might help design new therapeutic strategies for NASH and HCC.

Dissecting the Balance Between Metabolic and Oncogenic Functions of Astrocyte-Elevated Gene-1/Metadherin

Obesity is an enormous global health problem, and obesity-induced nonalcoholic steatohepatitis (NASH) is contributing to a rising incidence and mortality for hepatocellular carcinoma (HCC). Increase in de novo lipogenesis and decrease in fatty acid β-oxidation (FAO) underlie hepatic lipid accumulation in NASH. Astrocyte-elevated gene-1/metadherin (AEG-1) overexpression contributes to both NASH and HCC. AEG-1 harbors an LXXLL motif through which it blocks activation of peroxisome proliferator activated receptor α (PPARα), a key regulator of FAO. To better understand the role of LXXLL motif in mediating AEG-1 function, using clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology, we generated a mouse model (AEG-1-L24K/L25H) in which the LXXLL motif in AEG-1 was mutated to LXXKH. We observed increased activation of PPARα in AEG-1-L24K/L25H livers providing partial protection from high-fat diet-induced steatosis. Interestingly, even with equal gene dosage levels, compared with AEG-1-wild-type livers, AEG-1-L24K/L25H livers exhibited increase in levels of lipogenic enzymes, mitogenic activity and inflammation, which are attributes observed when AEG-1 is overexpressed. These findings indicate that while LXXLL motif favors steatotic activity of AEG-1, it keeps in check inflammatory and oncogenic functions, thus maintaining a homeostasis in AEG-1 function. AEG-1 is being increasingly appreciated as a viable target for ameliorating NASH and NASH-HCC, and as such, in-depth understanding of the functions and molecular attributes of this molecule is essential. Conclusion: The present study unravels the unique role of the LXXLL motif in mediating the balance between the metabolic and oncogenic functions of AEG-1.

MicroRNA-217: a therapeutic and diagnostic tumor marker

INTRODUCTION

Cancer as one of the most common causes of death has always been one of the major health challenges globally. Since, the identification of tumors in the early tumor stages can significantly reduce mortality rates; it is required to introduce novel early detection tumor markers. MicroRNAs (miRNAs) have pivotal roles in regulation of cell proliferation, migration, apoptosis, and tumor progression. Moreover, due to the higher stability of miRNAs than mRNAs in body fluids, they can be considered as non-invasive diagnostic or prognostic markers in cancer patients.

AREAS COVERED

In the present review we have summarized the role of miR-217 during tumor progressions. The miR-217 functions were categorized based on its target molecular mechanisms and signaling pathways.

EXPERT OPINION

It was observed that miR-217 mainly exerts its function by regulation of the transcription factors during tumor progressions. The WNT, MAPK, and PI3K/AKT signaling pathways were also important molecular targets of miR-217 in different cancers. The present review clarifies the molecular biology of miR-217 and paves the way of introducing miR-217 as a non-invasive diagnostic marker and therapeutic target in cancer therapy.

Astrocyte elevated gene-1 (AEG-1): A key driver of hepatocellular carcinoma (HCC)

An array of human cancers, including hepatocellular carcinoma (HCC), overexpress the oncogene Astrocyte elevated gene-1 (AEG-1). It is now firmly established that AEG-1 is a key driver of carcinogenesis, and enhanced expression of AEG-1 is a marker of poor prognosis in cancer patients. In-depth studies have revealed that AEG-1 positively regulates different hallmarks of HCC progression including growth and proliferation, angiogenesis, invasion, migration, metastasis and resistance to therapeutic intervention. By interacting with a plethora of proteins as well as mRNAs, AEG-1 regulates gene expression at transcriptional, post-transcriptional, and translational levels, and modulates numerous pro-tumorigenic and tumor-suppressive signal transduction pathways. Even though extensive research over the last two decades using various in vitro and in vivo models has established the pivotal role of AEG-1 in HCC, effective targeting of AEG-1 as a therapeutic intervention for HCC is yet to be achieved in the clinic. Targeted delivery of AEG-1 small interfering ribonucleic acid (siRNA) has demonstrated desired therapeutic effects in mouse models of HCC. Peptidomimetic inhibitors based on protein-protein interaction studies has also been developed recently. Continuous unraveling of novel mechanisms in the regulation of HCC by AEG-1 will generate valuable knowledge facilitating development of specific AEG-1 inhibitory strategies. The present review describes the current status of AEG-1 in HCC gleaned from patient-focused and bench-top studies as well as transgenic and knockout mouse models. We also address the challenges that need to be overcome and discuss future perspectives on this exciting molecule to transform it from bench to bedside.

Multifunctional Role of Astrocyte Elevated Gene-1 (AEG-1) in Cancer: Focus on Drug Resistance

Simple Summary

Chemotherapy is a major mode of treatment for cancers. However, cancer cells adapt to survive in stressful conditions and in many cases, they are inherently resistant to chemotherapy. Additionally, after initial response to chemotherapy, the surviving cancer cells acquire new alterations making them chemoresistant. Genes that help adapt the cancer cells to cope with stress often contribute to chemoresistance and one such gene is Astrocyte elevated gene-1 (AEG-1). AEG-1 levels are increased in all cancers studied to date and AEG-1 contributes to the development of highly aggressive, metastatic cancers. In this review, we provide a comprehensive description of the mechanism by which AEG-1 augments tumor development with special focus on its ability to regulate chemoresistance. We also discuss potential ways to inhibit AEG-1 to overcome chemoresistance.

Abstract

Cancer development results from the acquisition of numerous genetic and epigenetic alterations in cancer cells themselves, as well as continuous changes in their microenvironment. The plasticity of cancer cells allows them to continuously adapt to selective pressures brought forth by exogenous environmental stresses, the internal milieu of the tumor and cancer treatment itself. Resistance to treatment, either inherent or acquired after the commencement of treatment, is a major obstacle an oncologist confronts in an endeavor to efficiently manage the disease. Resistance to chemotherapy, chemoresistance, is an important hallmark of aggressive cancers, and driver oncogene-induced signaling pathways and molecular abnormalities create the platform for chemoresistance. The oncogene Astrocyte elevated gene-1/Metadherin (AEG-1/MTDH) is overexpressed in a diverse array of cancers, and its overexpression promotes all the hallmarks of cancer, such as proliferation, invasion, metastasis, angiogenesis and chemoresistance. The present review provides a comprehensive description of the molecular mechanism by which AEG-1 promotes tumorigenesis, with a special emphasis on its ability to regulate chemoresistance.

Angiopoietin 2 signal complexity in cardiovascular disease and cancer

The angiopoietin signal transduction system is a complex of vascular-specific kinase pathways that plays a crucial role in angiogenesis and maintenance of vascular homeostasis. Angiopoietin1 (Ang1) and 2 (Ang2), the ligand proteins of the pathway, belong to a family of glycoproteins that signal primarily through the transmembrane Tyrosine-kinase-2 receptor. Despite a considerable sequence homology, Ang1 and Ang2 manifest antagonistic effects in pathophysiological conditions. While Ang1 promotes the activation of survival pathways and the stabilization of the normal mature vessels, Ang2 can either favor vessel destabilization and leakage or promote abnormal EC proliferation in a context-dependent manner. Altered Ang1/Ang2 balance has been reported in various pathological conditions in association with inflammation and deregulated angiogenesis. In particular, increased Ang2 levels have been documented in human cancer and cardiovascular disease (CVD), including ischemic myocardial injury, heart failure and other cardiovascular complications secondary to diabetes, chronic renal damage and hypertension. Despite the obvious phenotypic differences, CVD and cancer share some common Ang2-dependent etiopathological mechanisms such as inflammation, epithelial (or endothelial) to mesenchymal transition, and adverse vascular network remodeling. Interestingly, both cancer and CVD are negatively affected by thyroid hormone dyshomeostasis. This review provides an overview of the complex Ang2-dependent signaling involved in CVD and cancer, as well as a survey of the related clinical literature. Moreover, on the basis of recent molecular acquisitions in an experimental model of post ischemic cardiac disease, the putative novel role of the thyroid hormone in the regulation of Ang1/Ang2 balance is also briefly discussed.

Trans-acting non-synonymous variant of FOXA1 predisposes to hepatocellular carcinoma through modulating FOXA1-ERα transcriptional program and may have undergone natural selection

Interplay of pioneer transcription factor forkhead box A1 (FOXA1) and estrogen receptor has been implicated in sexual dimorphism in hepatocellular carcinoma (HCC), but etiological relevance of its polymorphism was unknown. In the case control study (1152 patients versus1242 controls), we observed significant increase in HCC susceptibility in hepatitis B virus carriers associated with a non-synonymous Thr83Ala variant of FOXA1 (odds ratio [OR], 1.28; 95% confidence interval [CI], 1.11−1.48, for Ala83-containing genotype, after validation in an independent population with 933 patients versus 1030 controls), a tightly linked (CGC)5/6or7 repeat polymorphism at its promoter (OR 1.32; 95% CI 1.10–1.60, for (CGC)6or7-repeat-containing genotype), and their combined haplotype (OR 1.50; 95% CI 1.24–1.81, for (CGC)6or7−Ala83 haplotype). The susceptible FOXA1-Ala83 impairs its interaction with ERα, attenuates transactivation toward some of their dual target genes, such as type 1 iodothyronine deiodinase, UDP glucuronosyltransferase 2 family, polypeptide B17 and sodium/taurocholate cotransporting polypeptide, but correlates with strengthened cellular expression of α-fetoprotein (AFP) and elevated AFP serum concentration in HCC patients (n = 1096). The susceptible FOXA1 cis-variant with (CGC)6or7 repeat strengthens the binding to transcription factor early growth response 1 and enhances promoter activity and gene expression. Evolutionary population genetics analyses with public datasets reveal significant population differentiation and unique haplotype structure of the derived protective FOXA1-Thr83 and suggest that it may have undergone positive natural selection in Chinese population. These findings epidemiologically highlight the functional significance of FOXA1-ERα transcriptional program and regulatory network in liver cancer development.

Expression and prognostic value of HER-2/neu, STAT3 and SOCS3 in hepatocellular carcinoma

BACKGROUND AND AIMS

Hepatocellular carcinoma (HCC) is a complex and heterogeneous tumor with several genomic alterations, while the viral-chemical etiology along with molecular mechanisms of HCC pathogenesis remains largely unknown. This study aimed to determine expression profile and prognostic value of HER-2/neu, STAT3 and SOCS3 in HCC.

METHODS

Immunohistochemistry and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were performed to evaluate the expression of HER-2/neu, STAT3 and SOCS3 in HCC tissues and adjacent normal tissues collected from 176 HCC patients.

RESULTS

HER-2/neu and STAT3 levels were higher and SOCS3 expression was lower in HCC tissues than in adjacent normal tissues. HER-2/neu, STAT3 and SOCS3 levels were associated with histological grade, tumor diameter, TNM stage, vascular invasion, lymph node metastasis and distant metastasis in HCC. SOCS3 expression was negatively associated with HER-2/neu and STAT3 expression. HCC patients with higher HER-2/neu and STAT3 levels had shorter overall, disease-free and disease-specific survival, whereas the opposite was found in patients with higher SOCS3 expression. In Cox regression analysis, tumor size, TNM stage, and STAT3 expression were identified as independent prognostic factors of HCC.

CONCLUSION

Taken together, these observations suggest that HER-2/neu, STAT3 and, SOCS3 are related to the aggressive tumor behavior and STAT3 has potential value as a prognostic factor for HCC.

Astrocyte Elevated Gene-1 Regulates Macrophage Activation in Hepatocellular Carcinogenesis

Chronic inflammation is a known hallmark of cancer and is central to the onset and progression of hepatocellular carcinoma (HCC). Hepatic macrophages play a critical role in the inflammatory process leading to HCC. The oncogene Astrocyte elevated gene-1 (AEG-1) regulates NFκB activation, and germline knockout of AEG-1 in mice (AEG-1-/-) results in resistance to inflammation and experimental HCC. In this study, we developed conditional hepatocyte- and myeloid cell-specific AEG-1-/- mice (AEG-1ΔHEP and AEG-1ΔMAC, respectively) and induced HCC by treatment with N-nitrosodiethylamine (DEN) and phenobarbital (PB). AEG-1ΔHEP mice exhibited a significant reduction in disease severity compared with control littermates, while AEG-1ΔMAC mice were profoundly resistant. In vitro, AEG-1-/- hepatocytes exhibited increased sensitivity to stress and senescence. Notably, AEG-1-/- macrophages were resistant to either M1 or M2 differentiation with significant inhibition in migration, endothelial adhesion, and efferocytosis activity, indicating that AEG-1 ablation renders macrophages functionally anergic. These results unravel a central role of AEG-1 in regulating macrophage activation and indicate that AEG-1 is required in both tumor cells and tumor microenvironment to stimulate hepatocarcinogenesis.Significance: These findings distinguish a novel role of macrophage-derived oncogene AEG-1 from hepatocellular AEG-1 in promoting inflammation and driving tumorigenesis. Cancer Res; 78(22); 6436-46. ©2018 AACR.

Nonthyroidal Illness Syndrome and Thyroid Hormone Actions at Integrin αvβ3

CONTEXT

The nonthyroidal illness syndrome (NTIS) is a constellation of changes in circulating thyroid hormone levels that occur in euthyroid patients with acute or chronic systemic diseases. The changes that occur include a reduction in serum T3, an increase in serum rT3, and variable changes in circulating T4 levels. No consensus exists regarding therapeutic intervention for NTIS.

METHODS

We briefly review the published literature on the physiological actions of T4 and of rT3-hormones that until recently have been seen to have little or no bioactivity-and analyze the apparent significance of changes in circulating T4 and T3 encountered in the setting of NTIS in patients with cancer. In the case of T4, these actions may be initiated at a cancer or endothelial cell plasma membrane receptor on integrin αvβ3 or at the cytoskeleton.

RESULTS

This review examines possible therapeutic intervention in NTIS in patients with cancer in terms of T4 reduction and T3 support. Evidence also exists that rT3 may support cancer.

CONCLUSIONS

Prospective study is proposed of pharmacological reduction of normal or elevated T4 in cancer-associated NTIS. We also support investigation of normally circulating levels of T3 in such patients.

miR‑96 inhibits EMT by targeting AEG‑1 in glioblastoma cancer cells

The induction of epithelial to mesenchymal transition (EMT) is important for carcinogenesis and cancer progression. Previous studies have estimated that microRNA (miRNA/miR) expression is associated with EMT via the regulation of the expression of target genes. miR-96 has been reported to exhibit a correlation with the EMT process. However, the functional role of miR-96 and its mechanism in glioblastoma multiforme (GBM) remains to be completely elucidated. The objective of the present study was to investigate the functional role and mechanism of miR-96 in the migration and invasion, in addition to proliferation, apoptosis and cell cycle distribution, of GBM. In the present study, the results suggested that the introduction of miR-96 significantly inhibited the migration and invasion, in addition to proliferation and cell cycle progression, of GBM cells and promoted their apoptosis in vitro, leading to the hypothesis that miR-96 may be a potential tumor suppressor. It was subsequently confirmed that astrocyte elevated gene-1 (AEG-1) was a direct target gene of miR-96, using a luciferase assay and reverse transcription-quantitative polymerase chain reaction analysis, in addition to western blotting. miR-96 was observed to downregulate the expression of AEG-1 at the mRNA and protein levels. Notably, AEG-1 may suppress EMT by increasing the expression levels of E-cadherin, an epithelial marker, and decreasing the expression levels of vimentin, a mesenchymal marker. Therefore, it was concluded that miR-96 may impede the EMT process by downregulating AEG-1 in GBM. Additionally, it was observed that inhibition of AEG-1 led to a similar effect compared with overexpression of miR-96 in GBM. In conclusion, the results of the present study demonstrated that miR-96 may act as a tumor suppressor by regulating EMT via targeting of AEG-1, suggesting that miR-96 may be a potential biomarker and anticancer therapeutic target for GBM in the future.

The impact of thyroid hormones on patients with hepatocellular carcinoma

BACKGROUND & AIMS

Hypothyroidism has recently been proposed as predisposing factor for HCC development. However, the role of thyroid hormones (TH) in established HCC is largely unclear. We investigated the impact of TH on clinical characteristics and prognosis of HCC patients.

METHODS

Of 838 patients diagnosed with nonsurgical HCC at the Division of Gastroenterology and Hepatology/Medical University of Vienna between 1992 and 2012, 667 patients fulfilled the inclusion criteria. The associations of thyroid function tests with patient, liver, and tumor characteristics as well as their impact on overall survival (OS) were investigated.

RESULTS

Thyroid hormone substitution was more often observed in patients with low thyroid-stimulating hormone (TSH) concentration and in patients with elevated free tetraiodthyronine (fT4). Patients with high TSH (>3.77uU/ml) concentrations had larger tumors, while the opposite was true for patients with low TSH (<0.44uU/ml) concentrations. Subjects with elevated fT4 (>1.66ng/dl) were more likely to have elevated CRP. While TSH was only associated with OS in univariate analysis (≤1.7 vs. >1.7uU/ml, median OS (95%CI), 12.3 (8.9-15.7 months) vs. 7.3 months (5.4-9.2 months); p = 0.003), fT4 (≤1.66 vs. >1.66ng/dl, median OS (95%CI), 10.6 (7.5-13.6 months) vs. 3.3 months (2.2-4.3 months); p = 0.007) remained an independent prognostic factor for OS (HR (95%CI) for fT4>1.66ng/dl, 2.1 (1.3-3.3); p = 0.002) in multivariate analysis.

CONCLUSIONS

TSH and fT4 were associated with prognostic factors of HCC (i.e., tumor size, CRP level). Elevated fT4 concentrations were independently associated with poor prognosis in HCC. Further studies are needed to characterize the role of TH in HCC in detail.

The essential role of MTDH in the progression of HCC: a study with immunohistochemistry, TCGA, meta-analysis and in vitro investigation

Recent studies found that metadherin (MTDH) played an essential role in hepatocellular carcinoma (HCC). Nevertheless, the exact function of MTDH in the pathogenesis of HCC was unclarified. In the present study, we aimed to investigate the clinical significance of MTDH in HCC and its effect on HCC cells. Immunohistochemistry (IHC) was performed to detect MTDH expression in HCC tissues. Data from The Cancer Genome Atlas (TCGA) and ONCOMINE was obtained to examine MTDH expression in HCC and its clinical significance. Meta-analysis was conducted to assess the correlation between MTDH expression and both the prognosis (Overall Survival (OS) or Disease-free Survival (DFS)) and clinicopathological features of HCC via STATA 12.0. In vitro experiments were performed to investigate the role of MTDH in cell growth, caspase-3/7 activity and apoptosis in HCC cells. The MTDH staining was remarkably stronger in HCC tissues than in non-cancer tissues from IHC, TCGA and ONCOMINE data. Moreover, MTDH-positive expression was significantly correlated with pathological grade, distant metastasis and hepatitis B virus (HBV) infection by IHC. For meta-analysis, MTDH expression was indicative of poor OS without heterogeneity in HCC patients. Additionally, MTDH expression was correlated with high-grade histological differentiation, non-vascular invasion and metastasis in HCC. In vitro experiments revealed that MTDH could the inhibit cell growth and activate caspase-3/7 activity and apoptosis in the four HCC cell lines. In conclusion, MTDH expression may serve as a novel targeting strategy for HCC due to its clinical significance and oncogenic function in HCC cells.

miR-217 suppresses proliferation, migration, and invasion promoting apoptosis via targeting MTDH in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has frequent incidence and the third highest mortality rate among cancers in the world. This study aimed to clarify the roles of miR-217 and metadherin (MTDH) in HCC. First, we identified that miR-217 expression was downregulated and MTDH expression was upregulated in the HCC tissues. Functional studies revealed that miR-217 negatively regulated MTDH expression via binding to the 3'-untranslated region of MTDH mRNA in the HCC cells. In our further studies, the miR-217 overexpression resulted in downregulation of MTDH expression in HCC cells. The miR-217 overexpression in HCC cells suppressed proliferation, migration, and invasion inducing apoptosis. Taken together, our study provides the initial evidence that the increase of MTDH expression is associated with the decrease of miR-217 expression in HCC. This study also suggests that miR-217 inhibits malignant progression of HCC in vitro and may be used for miRNA-based therapy, possibly via directly targeting MTDH.

T3/TRs axis in hepatocellular carcinoma: new concepts for an old pair

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide, and its burden is expected to further increase in the next years. Chronic inflammation, induced by multiple viruses or metabolic alterations, and epigenetic and genetic modifications, cooperate in cancer development via a combination of common and distinct aetiology-specific pathways. In spite of the advances of classical therapies, the prognosis of this neoplasm has not considerably improved over the past few years. The advent of targeted therapies and the approval of the systemic treatment of advanced HCC with the kinase inhibitor sorafenib have provided some hope for the future. However, the benefits obtained from this treatment are still disappointing, as it extends the median life expectancy of patients by only few months. It is thus mandatory to find alternative effective treatments. Although the role played by thyroid hormones (THs) and their nuclear receptors (TRs) in human cancer is still unclear, mounting evidence indicates that they behave as oncosuppressors in HCC. However, the molecular mechanisms by which they exert this effect and the consequence of their activation following ligand binding on HCC progression remain elusive. In this review, we re-evaluate the existing evidence of the role of TH/TRs in HCC development; we will also discuss how TR alterations could affect fundamental biological processes, such as hepatocyte proliferation and differentiation, and consequently HCC progression. Finally, we will discuss if and how TRs can be foreseen as therapeutic targets in HCC and whether selective TR modulation by TH analogues may hold promise for HCC treatment.

AEG-1 as a predictor of sensitivity to neoadjuvant chemotherapy in advanced epithelial ovarian cancer

Objectives

Astrocyte elevated gene-1 (AEG-1) plays a critical role in tumor progression and chemoresistance. The aim of the present study was to investigate the protein expression of AEG-1 in patients with epithelial ovarian cancer (EOC) who underwent debulking surgery after neoadjuvant chemotherapy (NAC).

Materials and methods

The protein expression of AEG-1 was analyzed using immunohistochemistry in 162 patients with EOC. The relationship between AEG-1 expression and chemotherapy resistance was assessed using univariate and multivariate logistic regression analyses with covariate adjustments.

Results

High AEG-1 expression was significantly associated with the International Federation of Gynecology and Obstetrics stage, age, serum cancer antigen-125 concentration, histological grade, the presence of residual tumor after the interval debulking surgery, and lymph node metastasis. Furthermore, AEG-1 expression was significantly higher in NAC-resistant disease than in NAC-sensitive disease (P<0.05). Multivariate analyses indicated that elevated AEG-1 expression predicted poor survival.

Conclusion

Our findings indicate that AEG-1 may be a potential new biomarker for predicting chemoresistance and poor prognoses in patients with EOC.

Astrocyte Elevated Gene-1 as a Novel Clinicopathological and Prognostic Biomarker for Gastrointestinal Cancers: A Meta-Analysis with 2999 Patients

BACKGROUND

There have been numerous articles as to whether the staining index (SI) of astrocyte elevated gene-1 (AEG-1) adversely affects clinical progression and prognosis of gastrointestinal cancers. Nevertheless, controversy still exists in terms of correlations between AEG-1 SI and clinicopathological parameters including survival data. Consequently, we conducted a comprehensive meta-analysis to confirm the role of AEG-1 in clinical outcomes of gastrointestinal carcinoma patients.

METHODS

We performed a comprehensive search in PubMed, ISI Web of Science, Cochrane Central Register of Controlled Trials, EMBASE, Science Direct, Wiley Online Library, China National Knowledge Infrastructure (CNKI), WanFang and Chinese VIP databases. STATA 12.0 (STATA Corp., College, TX) was used to analyze the data extracted from suitable studies and Newcastle-Ottawa Scale was applied to assess the quality of included articles.

RESULTS

The current meta-analysis included 2999 patients and our results suggested that strong associations emerged between AEG-1 SI and histological differentiation (OR = 2.129, 95%CI: 1.377-3.290, P = 0.001), tumor (T) classification (OR = 2.272, 95%CI: 1.147-4.502, P = 0.019), lymph node (N) classification (OR = 2.696, 95%CI: 2.178-3.337, P<0.001) and metastasis (M) classification (OR = 3.731, 95%CI: 2.167-6.426, P<0.001). Furthermore, high AEG-1 SI was significantly associated with poor overall survival (OS) (HR = 2.369, 95%CI: 2.005-2.800, P<0.001) and deteriorated disease-free survival (DFS) (HR = 1.538, 95%CI: 1.171-2.020, P = 0.002). For disease-specific survival (DSS) and relapse-free survival (RFS), no statistically significant results were observed (HR = 1.573, 95%CI: 0.761-3.250, P = 0.222; HR = 1.432, 95%CI: 0.108-19.085, P = 0.786). Subgroup analysis demonstrated that high AEG-1 SI was significantly related to poor prognosis in esophageal squamous cell carcinoma (ESCC) (HR = 1.715, 95%CI: 1.211-2.410, P = 0.002), gastric carcinoma (GC) (HR = 2.255, 95%CI: 1.547-3.288, P<0.001), colorectal carcinoma (CRC) (HR = 2.922, 95%CI: 1.921-4.444, P<0.001), gallbladder carcinoma (GBC) (HR = 3.047, 95%CI: 1.685-5.509, P<0.001), hepatocellular carcinoma (HCC) (HR = 2.245, 95%CI: 1.620-3.113, P<0.001), pancreatic adenocarcinoma (PAC) (HR = 2.408, 95%CI: 1.625-3.568, P<0.001).

CONCLUSIONS

The current meta-analysis indicated that high AEG-1 SI might be associated with tumor progression and poor survival status in patients with gastrointestinal cancer. AEG-1 might play a vital role in promoting tumor aggression and could serve as a potential target for molecular treatments. Further clinical trials are needed to validate whether AEG-1 SI provides valuable insights into improving treatment decisions.