High expression of astrocyte elevated gene-1 is associated with clinical staging, metastasis, and unfavorable prognosis in gastric carcinoma

miRNA-559 and MTDH as possible diagnostic markers of psoriasis: Role of PTEN/AKT/FOXO pathway in disease pathogenesis

Psoriasis is a persistent, inflammatory, autoimmune skin disorder which can be elicited by genetic and environmental factors. Several microRNAs (miRNAs) that are abnormally expressed in psoriasis have emerged as an interesting candidate in psoriasis pathogenesis. However, the expression profile and function of miRNA-559, and its direct target metadherin (MTDH), in psoriasis need to be further illuminated. This study intended to assess miRNA-559 and MTDH levels in skin and sera of psoriatic patients and to investigate their clinical significance in an attempt for developing novel distinct tools for early diagnosis of psoriasis. Moreover, this study aimed at exploring participation of miRNA-559 in regulating MTDH/PTEN/AKT pathway in psoriasis. Expression levels of miRNA-559, AKT, FOXO1 and PTEN were measured by real-time qRT-PCR, whereas MTDH and p27 levels were assessed by ELISA in lesional, non-lesional tissues and serum of 20 psoriatic patients and 20 matching controls. Correlation study was conducted between different parameters. The diagnostic performance of miRNA-559 and MTDH in psoriasis was estimated by receiver operating characteristic (ROC) curve analysis. Expression of miRNA-559 in psoriatic patients was significantly downregulated in both lesional tissues and serum as compared to controls. Conversely, MTDH protein level showed significant increase in both tissues and serum of psoriatic patients and was inversely correlated with miRNA-559 level. Meanwhile, levels of PTEN, AKT and FOXO1 were dramatically changed in psoriatic patients compared to controls. Furthermore, serum miRNA-559 and MTDH displayed comparable diagnostic accuracy in discriminating psoriatic patients from controls. Yet, miRNA-559 demonstrated superior diagnostic performance than MTDH in psoriasis diagnosis. Together, the current findings provide the first suggestion of a new mechanism by which downregulation of miRNA-559 might induce proliferation in psoriasis through modulating PTEN/AKT/FOXO1 pathway by positive regulation of MTDH. Thus, miRNA-559 and MTDH might be proposed as promising diagnostic biomarkers of psoriasis.

Emerging Role and Clinicopathological Significance of AEG-1 in Different Cancer Types: A Concise Review

Tumor breakthrough is driven by genetic or epigenetic variations which assist in initiation, migration, invasion and metastasis of tumors. Astrocyte elevated gene-1 (AEG-1) protein has risen recently as the crucial factor in malignancies and plays a potential role in diverse complex oncogenic signaling cascades. AEG-1 has multiple roles in tumor growth and development and is found to be involved in various signaling pathways of: (i) Ha-ras and PI3K/AKT; (ii) the NF-κB; (iii) the ERK or mitogen-activated protein kinase and Wnt or β-catenin and (iv) the Aurora-A kinase. Recent studies have confirmed that in all the hallmarks of cancers, AEG-1 plays a key functionality including progression, transformation, sustained angiogenesis, evading apoptosis, and invasion and metastasis. Clinical studies have supported that AEG-1 is actively intricated in tumor growth and progression which includes esophageal squamous cell, gastric, colorectal, hepatocellular, gallbladder, breast, prostate and non-small cell lung cancers, as well as renal cell carcinomas, melanoma, glioma, neuroblastoma and osteosarcoma. Existing studies have reported that AEG-1 expression has been induced by Ha-ras through intrication of PI3K/AKT signaling. Conversely, AEG-1 also activates PI3K/AKT pathway and modulates the defined subset of downstream target proteins via crosstalk between the PI3K/AKT/mTOR and Hedgehog signaling cascade which further plays a crucial role in metastasis. Thus, AEG-1 may be employed as a biomarker to discern the patients of those who are likely to get aid from AEG-1-targeted medication. AEG-1 may play as an effective target to repress tumor development, occlude metastasis, and magnify the effectiveness of treatments. In this review, we focus on the molecular mechanism of AEG-1 in the process of carcinogenesis and its involvement in regulation of crosstalk between the PI3K/AKT/mTOR and Hedgehog signaling. We also highlight the multifaceted functions, expression, clinicopathological significance and molecular inhibitors of AEG-1 in various cancer types.

The Scope of Astrocyte Elevated Gene-1/Metadherin (AEG-1/MTDH) in Cancer Clinicopathology: A Review

Since its initial cloning in 2002, a plethora of studies in a vast number of cancer indications, has strongly established AEG-1 as a bona fide oncogene. In all types of cancer cells, overexpression and knockdown studies have demonstrated that AEG-1 performs a seminal role in regulating proliferation, invasion, angiogenesis, metastasis and chemoresistance, the defining cancer hallmarks, by a variety of mechanisms, including protein-protein interactions activating diverse oncogenic pathways, RNA-binding promoting translation and regulation of inflammation, lipid metabolism and tumor microenvironment. These findings have been strongly buttressed by demonstration of increased tumorigenesis in tissue-specific AEG-1 transgenic mouse models, and profound resistance of multiple types of cancer development and progression in total and conditional AEG-1 knockout mouse models. Additionally, clinicopathologic correlations of AEG-1 expression in a diverse array of cancers establishing AEG-1 as an independent biomarker for highly aggressive, chemoresistance metastatic disease with poor prognosis have provided a solid foundation to the mechanistic and mouse model studies. In this review a comprehensive analysis of the current and up-to-date literature is provided to delineate the clinical significance of AEG-1 in cancer highlighting the commonality of the findings and the discrepancies and discussing the implications of these observations.

Long Noncoding RNA DLGAP1-AS1 Promotes the Aggressive Behavior of Gastric Cancer by Acting as a ceRNA for microRNA-628-5p and Raising Astrocyte Elevated Gene 1 Expression

Purpose

The long noncoding RNA DLGAP1 antisense RNA 1 (DLGAP1-AS1) plays well-defined roles in the malignant progression of hepatocellular carcinoma. The purpose of this study was to determine whether DLGAP1-AS1 affects the aggressive behavior of gastric cancer (GC).

Methods

DLGAP1-AS1 expression in GC tissue samples and cell lines was determined by reverse-transcription quantitative PCR. GC cell proliferation, apoptosis, migration, invasion, and tumor growth in vitro as well as in vivo were examined by the Cell Counting Kit-8 assay, flow-cytometric analysis, transwell migration and invasion assays, and xenograft model experiments, respectively.

Results

DLGAP1-AS1 was overexpressed in GC tissue samples and cell lines. Among patients with GC, the increased level of DLGAP1-AS1 correlated with tumor size, TNM stage, lymph node metastasis, distant metastasis, and shorter overall survival. The knockdown of DLGAP1-AS1 suppressed GC cell proliferation, migration, and invasion in vitro, as well as promoted cell apoptosis and hindered tumor growth in vivo. Mechanistically, DLGAP1-AS1 functioned as a competing endogenous RNA for microRNA-628-5p (miR-628-5p) in GC cells, thereby increasing the expression of the miR-628-5p target astrocyte elevated gene 1 (AEG-1). Functionally, the recovery of the miR-628-5p/AEG-1 axis output attenuated the effects of DLGAP1-AS1 knockdown in GC cells.

Conclusion

DLGAP1-AS1 is a pleiotropic oncogenic lncRNA in GC. DLGAP1-AS1 plays a pivotal part in the oncogenicity of GC in vitro and in vivo by regulating the miR-628-5p/AEG-1 axis. DLGAP1-AS1, miR-628-5p, and AEG-1 form a regulatory pathway to facilitate GC progression, suggesting this pathway as an effective target for the treatment of GC.

Role of serum Metadherin mRNA expression in the diagnosis and prediction of survival in patients with colorectal cancer

Early diagnosis and treatment of colorectal cancer (CRC) are important for improving patients' survival. Metadherin is an oncogene that plays a pivotal role in carcinogenesis and can be suggested as a cancer biomarker. This study aimed to elucidate the efficacy of serum Metadherin mRNA expression as a potential non-invasive biomarker for early diagnosis of CRC in relation to other screening markers as carcinoembryonic antigen (CEA), carbohydrate antigen 19.9 (CA19.9) and Fecal occult blood (FOB) and also to assess its relationship with the tumor stage and survival rate. A convenience series of 86 CRC cases (group I) were recruited with 78 subjects as controls (group II). Serum Metadherin mRNA expression level was determined using reverse transcription polymerase chain reaction (RT-PCR). Serum Metadherin mRNA expression level was significantly elevated in CRC cases when compared with controls (P < 0.001). For CRC diagnosis; Receiver operator characteristic (ROC) analyses revealed that the diagnostic accuracy of serum Metadherin mRNA (AUC = 0.976) was significantly higher than other routine CRC screening markers as CEA, CA19.9 and FOB. The combined accuracy of these markers (AUC = 0.741) was increased when used with serum Metadherin mRNA (AUC = 0.820). High serum Metadherin mRNA expression was associated with poorly differentiated histological grade, advanced tumor stage and lower survival rate. AUC of Metadherin was 0.820 for differentiating advanced versus early tumor stages. Serum Metadherin mRNA expression is a useful non-invasive biomarker for CRC. It can be used for screening and early diagnosis of CRC and can increase the efficacy of other routine CRC screening markers when it is estimated in CRC patients with them. It is also associated with advanced tumor stage and a lower survival rate.

MicroRNA‑758 inhibits tumorous behavior in tongue squamous cell carcinoma by directly targeting metadherin

Numerous microRNAs (miRNAs) are dysregulated in tongue squamous cell carcinoma (TSCC), and their dysregulation has been demonstrated to have a strong correlation with TSCC progression via regulation of their targets. Therefore, miRNAs have potential use in the diagnosis and treatment of patients with TSCC. In the present study, miRNA‑758 (miR‑758) expression in TSCC tissues and cell lines was detected through reverse transcription‑quantitative polymerase chain reaction, and the effects of miR‑758 on TSCC cell proliferation and invasion were investigated by using Cell Counting kit‑8 and Transwell invasion assays. A luciferase reporter assay was performed to determine the target interaction between miR‑758 and metadherin (MTDH) in TSCC cells. The results revealed that miR‑758 was downregulated in TSCC tissues and cell lines. miR‑758 overexpression restricted the proliferation and invasion of TSCC cells. Additionally, MTDH was verified as a direct target gene of miR‑758 in TSCC cells. Furthermore, MTDH was observed to be upregulated in TSCC tissues, and the upregulation of MTDH was inversely correlated with miR‑758 expression. Moreover, restored MTDH expression significantly counteracted the suppressive effects of miR‑758 overexpression on TSCC cells. These results suggested that miR‑758 may prevent TSCC progression and development by directly targeting MTDH, thereby providing evidence that miR‑758 is a novel therapeutic target for the treatment of patients with TSCC.

MicroRNA‑874 prohibits the proliferation and invasion of retinoblastoma cells by directly targeting metadherin

MicroRNAs (miRNAs/miRs) serve important roles in regulating gene expression by directly binding to the 3'‑untranslated regions of target genes. Multiple miRNAs are dysregulated in retinoblastoma (RB) and their dysregulation is closely related to RB malignancy. Therefore, exploring the detailed roles of miRNAs in RB is valuable to facilitate the development of effective therapeutic targets for patients with this disease. miRNA‑874‑3p (miR‑874) has been recently reported to be downregulated in several types of human cancer and serves an essential role in cancer progression. However, the expression pattern and detailed roles of miR‑874 in RB, as well as the underlying molecular mechanisms in RB, have not been clearly elucidated. Therefore, this study detected miR‑874 expression in RB tissues and cell lines. The biological roles of miR‑874 in RB were determined and the underlying mechanisms of its actions in RB cells were also examined. This study revealed that miR‑874 expression was aberrantly underexpressed in RB tissues and cell lines. However, returning miR‑874 expression restricted the proliferative and invasive abilities of RB cells. In terms of the underlying mechanism, metadherin (MTDH) was validated as a direct target gene of miR‑874 in RB cells. MTDH inhibition could imitate the inhibitory roles of miR‑874 overexpression in RB cells. Furthermore, forced MTDH expression partially reversed the suppressive effects of miR‑874 on RB cells. In conclusion, this study revealed that miR‑874 may inhibit RB progression by directly targeting MTDH. Restoration of miR‑874 expression may be a novel strategy for preventing the rapid growth and metastasis of RB cells.

MicroRNA‑655 suppresses cell proliferation and invasion in oral squamous cell carcinoma by directly targeting metadherin and regulating the PTEN/AKT pathway

MicroRNAs (miRNAs) are important regulators of a variety of biological processes and their dysregulation is closely related to cancer formation and progression. Therefore, examination of aberrantly expressed miRNAs in oral squamous cell carcinoma (OSCC) may provide important clues for the diagnosis and treatment of patients with OSCC. The aim of the present study was to determine miRNA (miR)‑655‑3p expression in OSCC tissues and cell lines, and to investigate the biological roles and mechanisms of miR‑655‑3p associated with OSCC. Data from the present study indicated that miR‑655 expression was significantly downregulated in human OSCC tissues and cell lines. Overexpression of miR‑655 attenuated cell proliferation and invasion in OSCC in vitro. Metadherin (MTDH) mRNA was predicted as a potential target of miR‑655 by bioinformatics analysis, and this was confirmed by luciferase reporter assay, reverse transcription‑quantitative polymerase chain reaction and western blot analysis. In OSCC tissues, MTDH was highly expressed and inversely correlated with miR‑655 expression levels. MTDH overexpression reversed the inhibitory effects of miR‑655 mimics in OSCC cells. Notably, the upregulation of miR‑655 expression inhibited the activation of the phosphatase and tensin homolog (PTEN)/RAC‑α serine/threonine‑protein kinase (AKT) pathway in OSCC cells. Therefore, these results may provide the first evidence that miR‑655 targets MTDH to inhibit proliferation and invasion of OSCC by inhibiting PTEN/AKT signaling. Thus, the restoration of miR‑655 expression may be a novel therapeutic strategy for patients with OSCC.

Silencing of astrocyte elevated gene-1 inhibits proliferation and migration of melanoma cells and induces apoptosis

Melanoma is an aggressive skin malignancy with a high mortality. Astrocyte elevated gene-1 (AEG-1), a downstream target of Ras and c-Myc, has been implicated in the development of multiple tumours, but its role in melanoma remains unclear. In the present study, the role of AEG-1 in melanoma was explored through AEG-1 silencing. Our results showed that silencing AEG-1 inhibited the proliferation of melanoma cells, induced cell cycle arrest, and reduced levels of cyclin A, cyclin B, cyclin D1, cyclin E, and cyclin-dependent kinase 2. AEG-1silencing also induced apoptosis in melanoma cells and altered the levels of cleaved caspase-3, B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein. Moreover, silencing AEG-1 suppressed the migration and invasion of melanoma cells, reduced the expressions and activities of matrix metallopeptidase (MMP)-2 and MMP-9, and inhibited the activation of the Wnt/β-catenin signalling pathway in melanoma cells. Furthermore, in vivo experiments revealed that AEG-1 silencing inhibited the growth of melanoma xenografts in nude mice. In summary, our study demonstrates an oncogenic role of AEG-1 in melanoma and suggests that AEG-1 may serve as a potential therapeutic target in the treatment of melanoma.

Astrocyte Elevated Gene 1 (AEG-1): A Promising Candidate for Molecular Targeted Therapy in Oral Squamous Cell Carcinomas

Background: Astrocyte elevated gene 1 (AEG-1), also known as metadherin, is an oncogene which is overexpressed in various types of cancer, playing important roles in invasion, metastasis, angiogenesis and chemotherapy resistance. Hence it might be used as a therapeutic target. The aim of this study was to evaluate the expression of AEG-1 as a novel molecular marker in oral squamous cell carcinomas and establish correlations with clinicopathologic factors. Materials and Methods: Thirty formalin fixed paraffin-embedded blocks of OSCC cases and 30 samples of normal oral mucosa with minimal inflammation were selected and stained immunohistochemically for AEG-1. Staining intensity and percentage of stained cells were scored according to nuclear and cytoplasmic staining of epithelial cells. Relationship between immunoreactivity and clinicopathologic factors were examined by T-test and Mann-Whitney. Results: AEG-1 expression in OSCCs was greater than in normal oral mucosa (P<0.05). However, nuclear and cytoplasmic expression of AEG-1 was not associated with any of the clinicopathologic factors, age and gender of patients, tumor location, smoking history, tumor staging and grading, metastasis to lymph nodes and distant metastasis ( P>0.05). Conclusion: The current results support some role of AEG-1 in genesis of oral squamous cell carcinomas.

MicroRNA-379 inhibits cell proliferation and invasion in glioma via targeting metadherin and regulating PTEN/AKT pathway

Numerous microRNAs (miRNAs) are aberrantly expressed in glioma, and implicated in glioma occurrence and development. Therefore, the development of miRNAs as potential therapeutic targets for the treatment of patients with glioma has been proposed. miR‑379 has been shown to be aberrantly expressed in the progression of malignant tumours. However, the expression, biological functions and mechanism of miR‑379 in glioma are yet to be fully understood. Hence, the present study aimed to detect miR‑379 expression, investigate its functional relevance and explore its associated molecular mechanism in glioma. In this study, miR‑379 expression was significantly downregulated in glioma tissues and cell lines. Enforced miR‑379 expression markedly suppressed the cell proliferation and invasion of glioma. Metadherin (MTDH) was identified as a direct target of miR‑379 in glioma. The miR‑379 expression and MTDH mRNA levels exhibited an inverse association in glioma tissues. The restoration of the MTDH expression partially rescued the inhibitory effects of miR‑379 overexpression on glioma cell proliferation and invasion, and the upregulation of miR‑379 inhibited the activation of phosphatase and tensin homolog (PTEN)/AKT serine/threonine kinase (AKT) signaling pathway. Overall, these findings demonstrated that miR‑379 may play tumour‑suppressing roles in glioma through downregulation of MTDH and regulation of the PTEN/AKT signaling pathway, suggesting that miR‑379 might be a possible target for the treatment of patients with this malignancy.

MicroRNA‑675 inhibits cell proliferation and invasion in melanoma by directly targeting metadherin

Melanoma is derived from melanocytes and accounts for ~80% of skin cancer-associated fatalities worldwide. The dysregulation of microRNAs (miRNAs/miRs) is involved in the development and progression of melanoma. Therefore, miRNAs may be novel diagnostic or prognostic biomarkers and promising therapeutic targets in the treatment of patients with melanoma. miR‑675 is differentially expressed in several types of human cancer and has important roles in the pathogenesis of several diseases. However, the expression levels and the biological roles of miR‑675 in melanoma remain unclear. Therefore, the present study aimed to assess the expression of miR‑675 in melanoma, explore the effects of miR‑675 on melanoma cells and investigate the underlying molecular mechanisms that may be involved in the actions of miR‑675. The present study indicated that miR‑675 expression was downregulated in melanoma tissues and cell lines. Functional assays demonstrated that the upregulation of miR‑675 impaired cell proliferation and invasion in melanoma. Bioinformatics analysis, luciferase reporter assay, reverse transcription‑quantitative polymerase chain reaction and western blot analysis demonstrated that metadherin (MTDH) was a direct target of miR‑675 in melanoma. The MTDH levels were upregulated in melanoma tissues and inversely correlated with the miR‑675 expression. Furthermore, restored MTDH expression rescued the inhibition effects in melanoma cells caused by miR‑675 overexpression. Thus, miR‑675 may be a potential therapeutic target for melanoma.

MicroRNA-584 inhibits cell proliferation and invasion in non-small cell lung cancer by directly targeting MTDH

Lung cancer is the third most frequent human malignant tumour and the leading cause of cancer-associated mortality worldwide. Emerging lines of evidence have demonstrated that microRNAs (miRNAs) are upregulated or downregulated in non-small cell lung cancer (NSCLC), and this phenomenon is involved in the regulation of various processes during tumorigenesis and progression, including tumour groWTh, apoptosis, cell invasion, and tumour metastasis. Therefore, understanding the molecular mechanism that associates abnormally expressed miRNAs with NSCLC formation and development may lead to the identification of novel diagnostic, and therapeutic targets for patients with NSCLC. miRNA-584 (miR-584) functions as a tumour suppressor in several types of cancer. However, the expression pattern, detailed biological function and underlying molecular mechanism of miR-584 in NSCLC remain unclear. Therefore, the present study detected the expression of miR-584 in NSCLC, investigated its role in NSCLC cells and determined its underlying molecular mechanism. In the current study, it was demonstrated that miR-584 was downregulated in NSCLC tissues and cell lines. Low miR-584 expression was correlated with tumour size, tumour node metastasis stage and distant metastasis. Overexpression of miR-584 inhibited cell proliferation and invasion in NSCLC. Additionally, metadherin was identified as a direct target gene of miR-584 in NSCLC as confirmed by a series of experiments. Moreover, upregulation of miR-584 was involved in the regulation of the phosphatase and tensin homolog/Akt serine/threonine kinase signalling pathway in NSCLC. Thus, miR-584 may serve as a tumor-suppressor, and the results of the present study provide a reference for future research into the potential mechanisms underlying NSCLC progression.

MicroRNA-197 inhibits gastric cancer progression by directly targeting metadherin

Gastric cancer is the fifth most frequent malignancy and the fourth most common cause of cancer‑associated mortality worldwide. MicroRNAs (miRNAs) are a group of small RNAs that regulate several cellular processes. In particular, a large number of miRNAs are involved in gastric cancer formation and progression. Thus, miRNAs may be considered as effective diagnostic biomarkers and therapeutic methods for gastric cancer. The aim of the current study was to detect miRNA (miR)‑197 expression in gastric cancer and to investigate its biological role and associated mechanism in gastric cancer. In the present study, miR‑197 expression was demonstrated to be considerably downregulated in gastric cancer tissues and cell lines. Its low expression level was associated with tumour size, invasive depth, tumour‑node‑metastasis staging and lymph node metastasis. High expression of miR‑197 inhibited tumour cell proliferation and invasion in vitro. Subsequently, metadherin (MTDH) was identified as a direct target gene of miR‑197 in gastric cancer, and this was confirmed by bioinformatics analysis, Dual‑luciferase reporter assay, reverse transcription quantitative polymerase chain reaction and western blot analysis. MTDH expression was upregulated in gastric cancer and was inversely correlated with miR‑197 expression levels. In addition, MTDH overexpression prevented the proliferation and inhibited invasion induced by miR‑197 overexpression. In addition, miR‑197 was demonstrated to regulate the phosphatase and tensin homolog (PTEN)/AKT signalling pathway in gastric cancer. The results of the present study suggested that miR‑197 serves a tumour‑suppressing role in human gastric carcinogenesis and progression by regulating the MTDH/PTEN/AKT signalling pathway. The miR‑197/MTDH axis may provide a novel effective therapeutic target for patients with gastric cancer.

MicroRNA-154 inhibits the growth and metastasis of gastric cancer cells by directly targeting MTDH

MicroRNAs (miRNAs) are a group of non-protein-coding, highly conserved single-stranded RNA molecules. The abnormal expression of miRNAs has been demonstrated to have an important function in the carcinogenesis and progression of gastric cancer. microRNA-154 (miR-154) has been reported to be downregulated in non-small cell lung, colorectal and prostate cancer. However, the expression and roles of miR-154 in gastric cancer remain to be established. The present study measured the expression levels of miR-154 in gastric cancer tissues and cell lines. miR-154 was found to be significantly downregulated in gastric cancer tissues and cell lines. In addition, functional studies indicated that the overexpression of miR-154 inhibited the proliferation, migration and invasion of gastric cancer cells. Using TargetScan, a dual luciferase reporter assay, reverse transcription-quantitative polymerase chain reaction and western blot analysis, metadherin (MTDH) was revealed as a novel miR-154 target. In addition, knocking down MTDH lead to a similar effect as overexpressing-154 in gastric cells. The present findings indicate that miR-154 was downregulated in gastric cancer, and inhibited tumor behaviors of gastric cancer cells partially through the downregulation of MTDH. Therefore, the miR-154/MTDH axis may be a novel therapeutic to treat patients with gastric cancer.

Post-trimodality expression levels of metadherin (MTDH) as a prognostic biomarker for esophageal adenocarcinoma patients

Resectable esophageal adenocarcinoma (EAC) patients often receive chemoradiation followed by surgery. However, most patients experience recurrences. Overexpression of MTDH, an oncoprotein with multiple functions, has been found to be associated with poor prognosis in breast cancer, glioblastoma, melanoma and various gastrointestinal malignancies, but not in EAC. We sought to establish its role in resistant EAC (post-treatment residual EAC). MTDH was assessed by immunohistochemistry in resected EAC, and results were correlated with clinical outcomes. MTDH expression was detectable in 72.5% (50/69) of patients, while expression levels were high (positive) in 50.7% (35/69). Of 69 patients analyzed, 25 had no relapse and 44 patients had a relapse (8 with local-regional and 36 with distant). The median follow-up duration was 3 years (0.4-11.6). The median overall survival was not associated with MTDH status (2.79 years for MTDH-negative and 3.60 years for MTDH-positive patients, p = 0.121). In addition, MTDH was not associated with either the type of relapse (local or distant), baseline clinical stage, tumor grade, presence of signet ring cells, surgical (yp) stage, percentage of residual EAC or presence of lymphovascular invasion. Our data reveal that MTDH is not a prognostic biomarker in resistant EAC after trimodality therapy.

AEG-1 induces gastric cancer metastasis by upregulation of eIF4E expression

Gastric cancer is the third leading cause of cancer-related deaths worldwide, and patients with lymph node, peritoneal and distant metastasis have a poor prognosis. Overexpression of Astrocyte-elevated gene-1 (AEG-1) has been reported to be correlated with the progression and metastasis of gastric cancer. However, its mechanisms are quite unclear. In this study, we found that elevated expression of AEG-1 was correlated with metastasis in human gastric cancer tissues. Moreover, gain- or loss-of-function of AEG-1, respectively, promoted or suppressed epithelial-mesenchymal transition (EMT), migration and invasion of gastric cancer cells. AEG-1 positively regulated eIF4E, MMP-9 and Twist expression. Manipulating eIF4E expression by transfection of overexpression constructs or siRNAs partially eliminated AEG-1-regulated EMT, cell migration and invasion. In addition, overexpression or knockdown of eIF4E promoted or suppressed EMT, cell migration and invasion in parallel with upregulation of MMP-9 and Twist expression, while manipulating eIF4E expression partially abrogated AEG-1-induced MMP-9 and Twist. Finally, silencing of AEG-1 expression not only inhibited tumour growth in parallel with downregulation of eIF4E, MMP-9 and Twist expression in a xenograft nude mouse model, but also suppressed lymph node and peritoneal metastasis of gastric cancer in an orthotopic nude mouse model. These findings suggest that AEG-1 promotes gastric cancer metastasis through upregulation of eIF4E-mediated MMP-9 and Twist, which provides new diagnostic markers and therapeutic targets for cancer metastasis.

The expressions of metadherin and LEF-1 in mucosa-associated lymphoid tissue lymphoma of ocular adnexal

AIM

To investigate the expressions of metadherin (astrocyte elevated gene-1, AEG-1) and lymphoid enhancer-binding factor-1 (LEF-1) in ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma.

METHODS

The expressions of AEG-1 and LEF-1 were detected on specimens harvested from patients suffering from MALT lymphoma and lymphadenosis of ocular adnexal in Ophthalmology Department, Affiliated Hospital of Qingdao University from 2000 to 2015 by immunohistochemical and polymerase chain reaction (PCR) analysis.

RESULTS

AEG-1 and LEF-1 expressions in MALT lymphoma was respectively higher than that in lymphadenosis, both by immunohistochemical and PCR analysis (P<0.05). Diversity of AEG-1 and LEF-1 expressions in different Ann Arbor clinical stages showed a statistically significant result (P<0.05). A positive relevance between AEG-1 and LEF-1 was observed in MALT ocular adnexal lymphoma (r=0.435, P=0.016).

CONCLUSION

The over expressions of AEG-1 and LEF-1 at the level of protein and mRNA participates in the tumorigenesis of ocular adnexal MALT lymphoma. They should act as a new biological marker for pathological diagnosis in the future.

SU6668 modulates prostate cancer progression by downregulating MTDH/AKT signaling pathway

Prostate cancer is the second leading cause of cancer deaths among men in Western counties and has increased in incidence also in China in recent years. Although diagnosis modalities for primary prostate cancer have markedly improved, there are still no effective therapies for metastatic prostate cancer. SU6668 is an inhibitor of the tyrosine kinase activity of three angiogenic receptors VEGFR2, PDGFRβ and FGFR1. There is strong experimental evidence that SU6668 can induce growth inhibition of various primary tumors. However, the function and molecular mechanism of SU6668 in prostate cancer has not been fully elucidated. In the present study, we found that SU6668 inhibited the proliferation and invasion of prostate cancer cells. Functional studies also demonstrated that SU6668 inhibited epithelial-mesenchymal transition in DU145 and LNCap cells. After treatment with SU6668, MTDH protein, which has been reported to be significantly overexpressed in many human tumor tissues, was downregulated in DU145 and LNCap cells. siRNA-mediated silencing of MTDH in prostate cancer cells decreased their proliferation and invasive capabilities, suggesting that SU6668 may inhibit cell proliferation and invasion of prostate cancer cells partly through downstream targeting of MTDH. Mechanistic investigations showed that AKT signaling pathway was inhibited after SU6668 treatment in prostate cancer cells. Moreover, a combination of SU6668 and PI3K-AKT pathway inhibitor LY29004 resulted in increased inhibition of cell proliferation and invasion in DU145 cells. Taken together, our findings revealed that SU6668 suppressed prostate cancer progression by downregulating MTDH/AKT signaling pathway and identified a promising therapeutic strategy for prostate cancer.

IL-8 interacts with metadherin promoting proliferation and migration in gastric cancer

It has been reported that IL-8 was involved in the promotion of invasion of Gastric Cancer (GC), however the underlying mechanism by which IL-8 was observed to be able to promote invasion remains unknown. Here, in our study, IL-8 was shown to be significantly up-regulated in GC compared with paired normal control tissues whose expression was markedly associated with inferior overall prognosis; and IL-8 was displayed to be capable of directly interacting with metadherin (MTDH), which in turn can up-regulate IL-8 expression. Blockage of IL-8/MTDH using specific mono-antibody can abolish the invasion IL-8 mediated. Taken together, our results may provide a novel explanation of working mechanism of IL-8 in the invasion of GC.

AEG-1/MTDH/LYRIC: A Promiscuous Protein Partner Critical in Cancer, Obesity, and CNS Diseases

Since its original discovery in 2002, AEG-1/MTDH/LYRIC has emerged as a primary regulator of several diseases including cancer, inflammatory diseases, and neurodegenerative diseases. AEG-1/MTDH/LYRIC has emerged as a key contributory molecule in almost every aspect of cancer progression, including uncontrolled cell growth, evasion of apoptosis, increased cell migration and invasion, angiogenesis, chemoresistance, and metastasis. Additionally, recent studies highlight a seminal role of AEG-1/MTDH/LYRIC in neurodegenerative diseases and obesity. By interacting with multiple protein partners, AEG-1/MTDH/LYRIC plays multifaceted roles in the pathogenesis of a wide variety of diseases. This review discusses the current state of understanding of AEG-1/MTDH/LYRIC regulation and function in cancer and other diseases with a focus on its association/interaction with several pivotal protein partners.

Metadherin regulates epithelial-mesenchymal transition in carcinoma

Metadherin (MTDH) was first identified in primary human fetal astrocytes exposed to HIV-1 in 2002 and then recognized as an important oncogene mediating tumorigenesis, progression, invasiveness, and metastasis of carcinomas. Epithelial–mesenchymal transition (EMT) is a vital process in embryonic development, organ repair, and cancer progression. MTDH and EMT have also been proved to be related to the prognosis of patients with cancers. Recent studies reveal a relationship between MTDH overexpression and EMT in some malignancies. This review highlights the overexpression of MTDH and EMT in cancers and their correlations in clinical studies. Positive correlations have been established between MTDH and mesenchymal biomarkers, and negative correlations between MTDH and epithelial biomarkers have also been established. Furthermore, experiments reveal EMT regulated by MTDH, and some signal pathways have been established. Some anticancer drugs targeting MTDH and EMT are introduced in this review. Some perspectives concerning EMT regulation by MTDH are also presented in this review.

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.

Glucose-6-phosphate dehydrogenase expression is correlated with poor clinical prognosis in esophageal squamous cell carcinoma

Increasing evidence has demonstrated that glucose-6-phosphate dehydrogenase (G6PD), a key metabolic enzyme, participating in pentose phosphate pathway (PPP), is tightly associated with development and progression of a variety of tumors. Here, we reported expression of G6PD and its association with the prognosis of the patients with esophageal squamous cell carcinoma (ESCC). The results revealed significantly elevated G6PD mRNA and protein expressions in ESCC tissues compared with normal tissues (P < 0.05). Furthermore, high G6PD expression was tightly associated with histological grade, TNM staging and lymph node metastasis (P < 0.05), but not related to the patients' age and gender (P > 0.05). Importantly, the survival time of G6PD-positive patients was markedly lower than that of G6PD-negative patients (P < 0.05). Most notably, Cox multivariate assay demonstrated that G6PD was an independent prognostic factor for the patients with ESCC. In conclusion, G6PD may be a novel predictor for the prognosis of the patients with ESCC.