Crosstalk between VEGF and MTA1 signaling pathways contribute to aggressiveness of breast carcinoma

Molecular Efficacy of Gnetin C as Dual-Targeted Therapy for Castrate-Resistant Prostate Cancer

SCOPE

Resistance of castrate-resistant prostate cancer (CRPC) to enzalutamide (Enz) involves the expression of constitutively active androgen receptor splice variant (AR-V7). In addition to altered AR pathways, CRPC is characterized by "non-AR-driven" signaling, which includes an overexpression of metastasis-associated protein 1 (MTA1). Combining natural compounds with anticancer drugs may enhance drug effectiveness while reducing adverse effects. In this study, the in vitro and in vivo anticancer effects of Gnetin C (GnC) alone and in combination with Enz against CRPC are examined.

METHODS AND RESULTS

The effects of GnC alone and in combination with Enz are assessed by cell viability, clonogenic survival, cell migration, and AR and MTA1 expression using 22Rv1 cells. The tumor growth in vivo is assessed by bioluminescent imaging, western blots, RT-PCR, and IHC. GnC alone and in combined treatment inhibit cell viability, clonogenic survival and migration, and AR and MTA1 expression in 22Rv1 cells. The underlying AR- and MTA1-targeted anticancer mechanisms of treatments in vivo involve inhibition of proliferation and angiogenesis, and induction of apoptosis.

CONCLUSION

The findings demonstrate that GnC alone and GnC combined with Enz effectively inhibits AR- and MTA1-promoted tumor-progression in advanced CRPC, which indicates its potential as a novel therapeutic approach for CRPC.

Role of progesterone on dexamethasone-induced alterations in placental vascularization and progesterone receptors in rats†

BACKGROUND

Intrauterine growth restriction (IUGR) is manifested by lower maternal progesterone levels, smaller placental size, and decreased placental vascularity indicated by lower expression of vascular endothelial growth factor (VEGF). Studies showed that progesterone increases angiogenesis and induces VEGF expression in different tissues. Therefore, the aim of the present study is to evaluate the effect of progesterone on placental vascular bed and VEGF expression and the modulation of nuclear and membranous progesterone receptors (PR) in dexamethasone-induced rat IUGR model.

METHODS

Pregnant Sprague-Dawley rats were allocated into four groups and given intraperitoneal injections of either saline, dexamethasone, dexamethasone, and progesterone or progesterone. Injections started on gestation day (DG) 15 and lasted until the days of euthanization (19 and 21 DG). Enzyme-linked immunosorbent assay was used to evaluate plasma progesterone levels. Real-time PCR and western blotting were used to evaluate gene and protein expressions of VEGF, and PR in labyrinth and basal placental zones. Immunohistochemistry was used to locate VEGF and different PRs in placental cells. Immunofluorescence was used to monitor the expression of blood vessel marker (αSMA).

RESULTS

Dexamethasone decreased the vascular bed fraction and the expression of VEGF in both placental zones. Progesterone co-treatment with dexamethasone prevented this reduction. Nuclear and membrane PRs showed tissue-specific expression in different placental zones and responded differently to both dexamethasone and progesterone.

CONCLUSIONS

Progesterone treatment improves the outcomes in IUGR pregnancy. Progesterone alleviated DEX-induced IUGR probably by promoting placental VEGF and angiogenesis.

Expression of Metastatic Tumor Antigen 1 Splice Variant Correlates With Early Recurrence and Aggressive Features of Hepatitis B Virus-Associated Hepatocellular Carcinoma

Overexpression of metastatic tumor antigen 1 (MTA1) was correlated with poor prognosis of hepatitis B virus (HBV)-associated hepatocellular carcinoma (HBV-HCC). The aim of this study was to examine the clinical significance of the expression of MTA1 and its exon 4-excluded form (MTA1dE4), the most abundant spliced variant of MTA1, in patients receiving curative resection for HBV-HCC. We collected 102 patients with HBV-HCC and received curative resection retrospectively and examined the expressions level of total MTA1/MTA1dE4 in their paired nontumor and tumor liver tissues by using RT-qPCR. The association between MTA1/MTA1dE4 expression and various tumor features as well as tumor recurrence was analyzed. During the median follow-up period of 4 years, 25 patients (24.5%) showed early recurrence (within 12 months postresection) and 42 (54.5%) showed late recurrence. In Kaplan-Meier analysis, MTA1dE4 overexpression in tumor, but not MTA1, was associated with early recurrence (P = 0.0365), but not late recurrence. In multivariate analysis, only alpha-fetoprotein (AFP) ≥200 ng/mL (P = 0.006) and large tumor size (P = 0.027) were correlated with early recurrence. In the subgroup of patients with AFP <200 ng/mL, high MTA1dE4, but not total MTA1, expression could help predict early recurrence (P = 0.0195). In vitro, wound healing and invasion assays were performed in HCC cells, and MTA1dE4 was found to exhibit a higher ability in promoting migration and invasion of hepatoma cells than full-length MTA1. Conclusion: MTA1dE4 expression is correlated with more aggressive tumor characteristics and might serve as a more sensitive marker for early recurrence of HBV-HCC, especially for low-AFP patients.

Metastasis-Associated 1 (MTA1) Gene Expression Promotes Angiogenesis in Mouse Xenografts from Human Non-Small Cell Lung Cancer (NSCLC) Cells

BACKGROUND This study aimed to investigate the effects of metastasis-associated 1 (MTA1) gene expression and gene silencing in human non-small cell lung cancer (NSCLC) cells in vitro and on angiogenesis in tumor xenografts in vivo in nude mice. MATERIAL AND METHODS Human H460 and H1299 NSCLC cell lines underwent transfection with lentiviral transfer plasmids (lenti) and short-interfering RNA (si-RNA) and included a control group, a lenti-MTA1 group, a lenti-si-MTA1 group, a lenti control group, and a si-RNA control group. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect MTA1 gene expression after cell transfection. MTA1 transfection was more effective in H460 cells, which were selected for further in vivo studies. Sixty Balb/c nude mice, containing human H460 cell tumor xenografts, included a control group (N=20), a lenti-MTA1 group (N=20), and a lenti-si-MTA1 group (N=20). Tumor tissue immunohistochemistry was used to detect the expression of MTA1 protein and microvessel density (MVD) using CD31. Western blot was used to quantify the expression of cyclooxygenase-2 (COX-2), angiopoietin 1/2 (Ang1/2), hypoxia-inducible factor 1-a (HIF-1a), and vascular endothelial growth factor (VEGF). RESULTS MTA1 silencing with si-RNA significantly reduced the tumor growth rate in nude mice (p<0.01), reduced tumor MVD, and 70% of mice survived for more than 30 days. MTA1 overexpression resulted in the death of all mice at 30 days after tumor inoculation and upregulated the expression of COX-2, Ang1/2, HIF-1a and VEGF, which were down-regulated by MTA1 silencing. CONCLUSIONS MTA1 gene expression promoted angiogenesis in mouse xenografts from human NSCLC cells.

Prognostic and clinical significance of metastasis-associated gene 1 overexpression in solid cancers: A meta-analysis

BACKGROUND

In the past 2 decades, metastasis-associated gene 1 (MTA1) has attracted attention for its close association with cancer progression and its roles in chromatin remodeling processes, making it a central gene in cancer. The present meta-analysis was performed to assess MTA1 expression in solid tumors.

MATERIALS AND METHODS

This analysis identified studies that evaluated the relationship between MTA1 expression and clinical characteristics or prognosis of patients with solid tumors via the PubMed, Cochrane Library, and Embase electronic databases. Fixed-effect and random-effect meta-analytical techniques were used to correlate MTA1 expression with outcome measures. The outcome variables are shown as odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

Analysis of 40 cohort studies involving 4564 cancer patients revealed a significant association of MTA1 overexpression with tumor patient age (>50 vs. <50 years: combined OR 0.73, 95% CI 0.57-0.94), tumor grade (G3/4 vs. G1/2: combined OR 1.94, 95% CI 1.48-2.53), tumor size (>3 cm vs. <3 cm: combined OR 2.35, 95% CI 1.73-3.19), T stage (T3/4 vs. T1/2: combined OR 2.11, 95% CI 1.74-2.56), lymph node metastasis (yes vs. no: combined OR 2.92, 95% CI 2.26-3.75), distant metastasis (yes vs. no: combined OR 2.26, 95% CI 1.42-3.59), TNM stage (III/IV vs. I/II: combined OR 2.50, 95% CI 1.84-3.38), vascular invasion (yes vs. no: combined OR 2.26, 95% CI 1.92-3.56), and poor overall survival time (HR 1.83; 95% CI: 1.53-2.20; P = .000).

CONCLUSIONS

Our analyses demonstrate that MTA1 was an effective predictor of a worse prognosis in tumor patients. Moreover, MTA1 may play important role in tumor progression and outcome, and targeting MTA1 may be a new strategy for anti-cancer therapy.

MTA1 promotes viability and motility in nasopharyngeal carcinoma by modulating IQGAP1 expression

Nasopharyngeal carcinoma (NPC) is frequently seen in Chinese, especially the population that resides in southeast China. Metastasis-associated protein 1 (MTA1) is a chromatin modifier and plays a role in tumor cell metastasis. IQGAP1 is a ubiquitously expressed protein that contributes to cytoskeleton remodeling. This study aimed to investigate the role of MTA1 and IQGAP1 in NPC malignant transformation. MTA1 and IQGAP1 expression in NPC (n = 43) and control tissues (n = 31) were detected using qRT-PCR, immunoblot, and immunohistochemistry. MTA1 was overexpressed in CNE-1 and CNE-2 cell line by pcDNA3.1/MTA1 transfection. Dominant-negative p53 was transfected to inhibit p53 activity. si-IQGAP1 or dominant-negative IQGAP1 (IQGAP1ΔGRD) was used to suppress IQGAP1 activity. Cell proliferation was measured by CKK-8 assay. Cell migration was evaluated by Transwell assay. The results showed that MTA1 and IQGAP1 were highly expressed in NPC tissues compared with the controls. Forced expression of MTA1 accelerated cell proliferation and migration and upregulated IQGAP1 expression in a p53-independent way. Knockdown of IQGAP1 or transfection of dominant-negative IQGAP1 impeded tumor cell proliferation and migration as well as PI3K/Akt signaling induced by MTA1. In conclusion, MTA1 participates in NPC malignant transformation via regulating IQGAP1 expression and PI3K/Akt signaling pathway.

Suppression of VEGF-induced angiogenesis and tumor growth by Eugenia jambolana, Musa paradisiaca, and Coccinia indica extracts

CONTEXT

Abnormal angiogenesis and evasion of apoptosis are hallmarks of cancer. Accordingly, anti-angiogenic and pro-apoptotic therapies are effective strategies for cancer treatment. Medicinal plants, namely, Eugenia jambolana Lam. (Myrtaceae), Musa paradisiaca L. (Musaceae), and Coccinia indica Wight & Arn. (Cucurbitaceae), have not been greatly investigated for their anticancer potential.

OBJECTIVE

We investigated the anti-angiogenic and pro-apoptotic efficacy of ethyl acetate (EA) and n-butanol (NB) extracts of E. jambolana (seeds), EA extracts of M. paradisiaca (roots) and C. indica (leaves) with respect to mammary neoplasia.

MATERIALS AND METHODS

Effect of extracts (2-200 μg/mL) on cytotoxicity and MCF-7, MDA-MB-231 and endothelial cell (EC) proliferation and in vitro angiogenesis were evaluated by MTT, 3[H]thymidine uptake and EC tube formation assays, respectively. In vivo tumour proliferation, VEGF secretion and angiogenesis were assessed using the Ehrlich ascites tumour (EAT) model followed by rat corneal micro-pocket and chicken chorioallantoic membrane (CAM) assays. Apoptosis induction was assessed by morphological and cell cycle analysis.

RESULTS

EA extracts of E. jambolana and M. paradisiaca exhibited the highest cytotoxicity (IC50 25 and 60 μg/mL), inhibited cell proliferation (up to 81%), and tube formation (83% and 76%). In vivo treatment reduced body weight (50%); cell number (16.5- and 14.7-fold), secreted VEGF (∼90%), neoangiogenesis in rat cornea (2.5- and 1.5-fold) and CAM (3- and 1.6-fold) besides EAT cells accumulation in sub-G1 phase (20% and 18.38%), respectively.

DISCUSSION AND CONCLUSION

Considering the potent anti-angiogenic and pro-apoptotic properties, lead molecules from EA extracts of E. jambolana and M. paradisiaca can be developed into anticancer drugs.

Metastasis-Associated Protein 1 Deficiency Results in Compromised Pulmonary Alveolar Capillary Angiogenesis in Mice

Background

The aim of this study was to investigate the effects of metastasis-associated protein 1 (MTA1) deficiency during angiogenesis of pulmonary alveolar capillaries in mice and to determine the molecular mechanisms involved.

Material/Methods

The expressions of MTA1, CD34, vascular endothelial growth factor (VEGF), alpha smooth muscle actin (α-SMA), and HIF-1α were analyzed in the lungs of MTA1-knockout (KO) and wild-type mice at embryonic day 18.5 and 2 months by quantitative PCR, immunoblotting, and immunohistochemistry. The morphological changes were investigated during pulmonary alveolar capillary formation. The heart weight/body weight (HW/BW) ratio and the size of the right ventricular wall cardiomyocytes were also measured. Regulation of MTA1 on HIF-1α was determined in vitro.

Results

MTA1 deficiency reduced the number of pulmonary alveolar capillaries compared to the wild-type mice. MTA1-KO mice exhibited a decreased expression of HIF-1α and VEGF in the lungs. The retarded growth of the MTA1-KO mice was also noticed during the first week after birth. Accordingly, MTA1 deficiency resulted in increased infant mortality. In surviving adult mice, MTA1 deficiency induced myocardial hypertrophy, highlighted by an increased heart weight/body weight ratio and larger cardiomyocytes. In cultured cells, HIF-1α and VEGF levels were significantly upregulated upon MTA1 overexpression, suggesting a close relationship between all 3 molecules.

Conclusions

MTA1 participates in the formation of pulmonary capillaries via stabilization of HIF-1α. This finding sheds new light on the function of MTA1 in lung development, opening new avenues for the diagnosis/treatment of related pulmonary diseases.

Associations between the expression of MTA1 and VEGF-C in esophageal squamous cell carcinoma with lymph angiogenesis and lymph node metastasis

The aim of the present study was to investigate the association between the expression levels of metastasis-related gene 1 (MTA1) and vascular endothelial growth factor C (VEGF-C) in esophageal squamous cell carcinoma (ESCC) with lymph angiogenesis and lymph node metastasis. The paraffin-embedded tissue samples of 107 cases of ESCC and 56 cases of normal esophageal tissues were collected from the Department of Cardiothoracic Surgery, Suining Central Hospital from March 2013 to January 2014. Immunohistochemical assays were performed to detect the expression levels of MTA1, VEGF-C and D2-40 in ESCC, and the micro-lymphatic vessel density (LVD) was evaluated. Their associations with various clinicopathological parameters were also analyzed. The protein expression levels of MTA1 and VEGF-C in ESCC were significantly higher compared with those in normal esophageal tissues (P<0.05); the high protein expression levels of MTA1 and VEGF-C in ESCC tissues at various tumor-node-metastasis stages exhibited statistically significant differences, as revealed by the Kruskal-Wallis test (P<0.05). The protein expression levels of MTA1 and VEGF-C in ESCC exhibited positive correlations (Spearman's ρ, r=0.512; P=0.000); the LVD level in the group with high expression of MTA1 and VEGF-C was significantly higher compared with in the low expression group (P<0.05). The comparison between MTA1 and VEGF-C protein expression levels in the group with a high rate of lymph node metastasis demonstrated statistically significant differences when compared with in the low lymph node metastasis group (P<0.05). The expression levels of MTA1 and VEGF-C in ESCC exhibited a positive correlation in ESCC, which may co-promote lymph angiogenesis and lymph node metastasis in ESCC; therefore, they may be used as biomarkers for determining the prognosis of ESCC.

MicroRNA-421 inhibits breast cancer metastasis by targeting metastasis associated 1

Dysregulation of microRNAs is involved in the initiation and progression of several human cancers, including breast cancer, as strong evidence of miRNAs acting as oncogenes or tumour suppressor genes has been found. This study was performed to investigate the biological functions of microRNA-421 (miR-421) in breast cancer and the underlying mechanisms. The expression level of miR-421 was detected in 50 pairs of surgical specimens and human breast cancer cell lines. The results showed that miR-421 is downregulated in breast cancer tissues and metastatic cell lines. In addition, the decrease in miR-421 levels was significantly associated with lymph node metastasis, recurrence/metastasis, or pTNM stage. Functions of miR-421 in cell migration and invasion were assessed through its silencing and overexpression. The results showed that miR-421 knockdown promotes invasion and metastasis in MCF-7 cells and its overexpression suppresses invasion and metastasis in MDA-MB-231 cells. The specific target genes of miR-421 were predicted by TargetScan algorithm and determined by dual luciferase reporter assay, quantitative reverse transcriptase PCR, and western blot analysis. miR-421 could suppress luciferase activity of the reporter containing 3'-untranslated region of metastasis associated 1 (MTA1), a potent oncogene. miR-421 overexpression or knockdown had no effect on the mRNA expression of MTA1, but it could modulate MTA1 protein level. Furthermore, MTA1 knockdown receded the effect of miR-421 inhibitor on invasion and metastasis of MCF-7 cells, and its overexpression receded the effect of miR-421 on invasion and metastasis of MDA-MB-231 cells. Our findings clearly demonstrate that miR-421 suppresses breast cancer metastasis by directly inhibiting MTA1 expression. The present study provides a new insight into the tumour suppressor roles of miR-421 and suggests that miR-421/MTA1 pathway is a putative therapeutic target in breast cancer.

Bioinformatic exploration of MTA1-regulated gene networks in colon cancer

Metastasis-associated gene 1 (MTA1) controls a series of biological processes in tumor progression. Tumor progression is a complex process regulated by a gene network. The global cancer gene regulatory network must be analyzed to determine the position of MTA1 in the molecular network and its cooperative genes by further exploring the biological functions of this gene. We used TCGA data sets and GeneCards database to screen MTA1-related genes. GO and KEGG pathway analyses were conducted with DAVID and gene network analysis via STRING and Cytoscape. Results showed that in the development of colon cancer, MTA1 is linked to certain signal pathways, such as Wnt/Notch/nucleotide excision repair pathways. The findings also suggested that MTA1 demonstrates the closest relationship in a coregulation process with the key molecules AKT1, EP300, CREBBP, SMARCA4, RHOA, and CAD. These results lead MTA1 exploration to an in-depth investigation in different directions, such as Wnt, Notch, and DNA repair.

Structure, expression and functions of MTA genes

Metastatic associated proteins (MTA) are integrators of upstream regulatory signals with the ability to act as master coregulators for modifying gene transcriptional activity. The MTA family includes three genes and multiple alternatively spliced variants. The MTA proteins neither have their own enzymatic activity nor have been shown to directly interact with DNA. However, MTA proteins interact with a variety of chromatin remodeling factors and complexes with enzymatic activities for modulating the plasticity of nucleosomes, leading to the repression or derepression of target genes or other extra-nuclear and nucleosome remodeling and histone deacetylase (NuRD)-complex independent activities. The functions of MTA family members are driven by the steady state levels and subcellular localization of MTA proteins, the dynamic nature of modifying signals and enzymes, the structural features and post-translational modification of protein domains, interactions with binding proteins, and the nature of the engaged and resulting features of nucleosomes in the proximity of target genes. In general, MTA1 and MTA2 are the most upregulated genes in human cancer and correlate well with aggressive phenotypes, therapeutic resistance, poor prognosis and ultimately, unfavorable survival of cancer patients. Here we will discuss the structure, expression and functions of the MTA family of genes in the context of cancer cells.

Unique DNA Methylation Patterns in Offspring of Hypertensive Pregnancy

Epigenomic processes are believed to play a pivotal role for the effect of environmental exposures in early life to modify disease risk throughout the lifespan. Offspring of women with hypertensive complications of pregnancy (HTNPREG ) have an increased risk of developing systemic and pulmonary vascular dysfunction in adulthood. In this preliminary report, we sought to determine whether epigenetic modifications of genes involved in the regulation of vascular function were present in HTNPREG offspring. We contrasted DNA methylation and gene expression patterns of peripheral blood mononuclear cells obtained from young male offspring of HTNPREG (n = 5) to those of normotensive controls (n = 19). In HTNPREG offspring we identified six differentially methylated regions (DMRs) including three genes (SMOC2, ARID1B and CTRHC1) relevant to vascular function. The transcriptional activity of ARID1B and CTRCH1 was inversely related to methylation status. HTNPREG offspring had higher systolic pulmonary artery pressure (sPPA ) versus controls. Our findings demonstrate that epigenetic marks are altered in offspring of HTNPREG with a modest elevation of sPPA and introduce novel epigenomic targets for further study. On the basis of these findings we speculate that epigenomic mechanisms may be involved in mediating the effect of HTNPREG to raise the risk of vascular disease later in life.

Gd-Metallofullerenol Nanomaterial Suppresses Pancreatic Cancer Metastasis by Inhibiting the Interaction of Histone Deacetylase 1 and Metastasis-Associated Protein 1

The treatment of pancreatic cancer frequently fails due to local recurrence and hepatic metastasis. Our previous study found that Gd@C82(OH)22 can suppress pancreatic cancer by inhibiting MMP-2/9 expression. In this study, we further explored the epigenetic mechanism of Gd@C82(OH)22 in human pancreatic cancer metastasis. Gd@C82(OH)22 suppressed tumor metastasis through down-regulation of metastasis-associated protein 1 (MTA1), HDAC1, HIF-1α, and MMP-2/9 and up-regulation of reversion-cysteine protein with the Kazal motif (RECK). The level of acetylation was increased in the promoter region of the RECK gene after Gd@C82(OH)22 treatment. The interaction of MTA1, HDAC1, and HIF-1α was inhibited by Gd@C82(OH)22. Furthermore, large-scale molecular dynamics simulations revealed Gd@C82(OH)22 could serve as an effective HDAC inhibitor to the protein-protein association between HDAC1 and MTA1, especially through MTA1's SANT and ELM2 dimerization domains. Our findings implicate Gd@C82(OH)22 as a novel HDAC inhibitor acting to increase RECK expression by suppressing the MTA1/HDAC1 co-repressor complex. Gd@C82(OH)22 may serve as a potential HDAC1 inhibitor to suppress pancreatic cancer cell invasion and metastasis both in vitro and in vivo. According to computer analysis and experimental validation, Gd@C82(OH)22 activates RECK expression by inhibiting the interaction of HDAC1 and MTA1.

MTA1 promotes proliferation and invasion in human gastric cancer cells

Although metastasis-associated protein 1 (MTA1) has been widely linked to tumor metastasis, the relevant mechanisms remain to be elucidated, especially in gastric cancer. The aim of this study was to examine whether the MTA1 gene is associated with the process of proliferation and invasion by regulating several molecular targets in gastric cancer. MTA1 expression in 61 gastric cancer tissue and adjacent noncancerous tissues was analyzed by immunohistochemistry. The prognostic value of MTA1 for overall survival and disease-free survival was determined by Kaplan-Meier estimates, and the significance of differences between curves was evaluated by the log-rank test. Furthermore, overexpression of MTA1 in SGC7901 and BGC823 cells promoted cell cycle progression, cell adhesion, and cell invasion. Our study found that MTA1 is overexpressed in gastric cancers, which contributes to malignant cell growth by facilitating cell cycle progression through upregulation of cyclin D1 and accelerates the migration and invasion of human gastric cancer cells by regulating expression of fibronectin and MMP2/MMP9. Taken together, MTA1 was involved in the pathogenesis of gastric cancer and might be a candidate therapeutic target in gastric cancer.

Endocrine MPA enhances the effects of TAC chemotherapy on improvement of prognosis and increase in long-term survival rates for patients with endometrial cancer

The aim of the present study was to investigate the effect of taxol, adriamycin and carboplatin (TAC) chemotherapy combined with endocrine medroxyprogesterone acetate (MPA) therapy for the treatment of patients with endometrial cancer. A retrospective analysis of 124 patients with endometrial cancer was performed by dividing the cohort into an experimental and control group. The 64 patients in the experimental group received TAC and MPA chemotherapy, whereas the 60 patients in the control group were treated with TAC chemotherapy only. Tissue samples scraped from the uterus were used to extract the total proteins and RNAs for the western blot and reverse transcription-quantitative polymerase chain reaction analyses, respectively. All the patients were followed up for 20-45 months, during which time prognostic data, and one- to three-year survival rates were recorded and compared. The rate of recurrence or metastasis was significantly lower in the experimental group compared with that in the control group (P<0.05) and the three-year survival rate of the experimental group was significantly higher than that of the control group (P<0.05). Furthermore, the mean metastasis-associated 1 (MTA1) protein and RNA expression levels were significantly lower in the experimental group compared with the control group (P<0.05), exhibiting ~30 and ~15% of the levels in the control group, respectively. Therefore, a treatment strategy of TAC chemotherapy combined with endocrine MPA therapy appears to effectively improve the prognosis and increase the long-term survival rates of patients with endometrial cancer. Such an enhancing effect may be mediated by the transcriptional downregulation of MTA1 expression.

Unravelling the Complexity and Functions of MTA Coregulators in Human Cancer

Since the initial recognition of the metastasis-associated protein 1 (MTA1) as a metastasis-relevant gene approximately 20 years ago, our appreciation for the complex role of the MTA family of coregulatory proteins in human cancer has profoundly grown. MTA proteins consist of six family members with similar structural units and act as central signaling nodes for integrating upstream signals into regulatory chromatin-remodeling networks, leading to regulation of gene expression in cancer cells. Substantial experimental and clinical evidence demonstrates that MTA proteins, particularly MTA1, are frequently deregulated in a wide range of human cancers. The MTA family governs cell survival, the invasive and metastatic phenotypes of cancer cells, and the aggressiveness of cancer and the prognosis of patients with MTA1 overexpressing cancers. Our discussion here highlights our current understanding of the regulatory mechanisms and functional roles of MTA proteins in cancer progression and expands upon the potential implications of MTA proteins in cancer biology and cancer therapeutics.

Metastatic tumor antigen in hepatocellular carcinoma: golden roads toward personalized medicine

Hepatocellular carcinoma (HCC), a prototype of hypervascular tumors, is one of the most common malignancies in the world, especially hyperendemic in the Far East where chronic hepatitis B virus (HBV) infection is highly prevalent. It is characterized by the clinical feature of a poor prognosis or a high mortality due to its already far advanced stages at diagnosis. It is so multifactorial that hepatocarcinogenesis cannot be explained by a single molecular mechanism. To date, a number of pathways have been known to contribute to the development, growth, angiogenesis, and even metastasis of HCC. Among the various factors, metastatic tumor antigens (MTAs) or metastasis-associated proteins have been vigorously investigated as an intriguing target in the field of hepatocarcinogenesis. According to recent studies including ours, MTAs are not only involved in the HCC development and growth (molecular carcinogenesis), but also closely associated with the post-operative recurrence and a poor prognosis or a worse response to post-operative anti-cancer therapy (clinical significance). Herein, we review MTAs in light of their essential structure, functions, and molecular mechanism in hepatocarcinogenesis. We will also focus in detail on the interaction between hepatitis B x protein (HBx) of HBV and MTA in order to clarify the HBV-associated HCC development. Finally, we will discuss the prognostic significance and clinical application of MTA in HCC. We believe that this review will help clinicians to understand the meaning and use of the detection of MTA in order to more effectively manage their HCC patients.

Clinical implications of MTA proteins in human cancer

Metastasis-associated gene or metastasis tumor antigen 1 (MTA1) is a new member of cancer progression-related gene family. It was first identified in rat mammary adenocarcinoma and later recognized as an important constituent of nucleosomal remodeling complex (NuRD), displaying dual regulatory functions as a co-repressor and co-activator for a large number of genes. Chromatin remodelers are ATP-dependent multi-protein chromatin modifying machines. These complexes alter the nucleosome positioning regulating the accessibility of genomic DNA to various transcription factors and thus modulate eukaryotic gene transcription. Since its identification two decades ago, MTA1 has been reported to be overexpressed in many cancers. Moreover, its overexpression has also been correlated with transformation and tumor progression. Furthermore, MTA1 has been shown to modulate the response of several tumor suppressor genes like p53 and oncogenes like c-myc. Taken together, current literature suggests that MTA proteins, especially MTA1, act as a master co-regulatory molecule involved in the carcinogenesis and progression of various malignant tumors. The primary focus of this review is to provide an overview of the MTA proteins with special emphasis on its role in cancer and use as a marker for cancer progression and potential target for therapy.

MTA1 overexpression induces cisplatin resistance in nasopharyngeal carcinoma by promoting cancer stem cells properties

Themetastasis-associated gene 1 (MTA1) oncogene hasbeen suggested to be involved in the regulation of cancer progression. However, there is still no direct evidence that MTA1 regulates cisplatin (CDDP) resistance, as well as cancer stem cell properties. In this study, we found that MTA1 was enriched in CNE1/CDDP cells. Knock down of MTA1 in CNE1/CDDP cells reversed CSCs properties and CDDP resistance. However, ectopic expression of MTA1 in CNE1 cells induced CSCs phenotypes and CDDP insensitivity. Interestingly, ectopic overexpression of MTA1-induced CSCs properties and CDDP resistance were reversed in CNE1 cells after inhibition of PI3K/Akt by LY294002. In addition, MTA1 expression and Akt activity in CNE1/CDDP cells was much higher than that in CNE1 cells. These results suggested that MTA1 may play a critical role in promoting CDDP resistance in NPC cells by regulatingcancer stem cell properties via thePI3K/Akt signaling pathway. Our findings suggested that MTA1 may be a potential target for overcoming CDDP resistance in NPC therapy.