Metastasis-associated 1 Research Articles

Inner Back Cover Image

ON THE INNER BACK COVER: Image of the skeletal muscles showing the striated localization pattern of metastasis associated 1 (MTA1).Credit: Chundong Gu (The First Affiliated Hospital of Dalian Medical University, Dalian, China) and Ming‐Fei Lang (Medical College, Dalian University, Dalian, China) image

HOXA-AS2 Epigenetically Inhibits HBV Transcription by Recruiting the MTA1-HDAC1/2 Deacetylase Complex to cccDNA Minichromosome.

Persistent transcription of HBV covalently closed circular DNA (cccDNA) is critical for chronic HBV infection. Silencing cccDNA transcription through epigenetic mechanisms offers an effective strategy to control HBV. Long non-coding RNAs (lncRNAs), as important epigenetic regulators, have an unclear role in cccDNA transcription regulation. In this study, lncRNA sequencing (lncRNA seq) is conducted on five pairs of HBV-positive and HBV-negative liver tissue. Through analysis, HOXA-AS2 (HOXA cluster antisense RNA 2) is identified as a significantly upregulated lncRNA in HBV-infected livers. Further experiments demonstrate that HBV DNA polymerase (DNA pol) induces HOXA-AS2 after establishing persistent high-level HBV replication. Functional studies reveal that HOXA-AS2 physically binds to cccDNA and significantly inhibits its transcription. Mechanistically, HOXA-AS2 recruits the MTA1-HDAC1/2 deacetylase complex to cccDNA minichromosome by physically interacting with metastasis associated 1 (MTA1) subunit, resulting in reduced acetylation of histone H3 at lysine 9 (H3K9ac) and lysine 27 (H3K27ac) associated with cccDNA and subsequently suppressing cccDNA transcription. Altogether, the study reveals a mechanism to self-limit HBV replication, wherein the upregulation of lncRNA HOXA-AS2, induced by HBV DNA pol, can epigenetically suppress cccDNA transcription.

Metastasis-associated 1 localizes to the sarcomeric Z-disc and is implicated in skeletal muscle pathology.

Metastasis-associated 1 (MTA1), a subunit of the nucleosome remodeling and histone deacetylation (NuRD) corepressor complex, was reported to be expressed in the cytoplasm of skeletal muscles. However, the exact subcellular localization and the functional implications of MTA1 in skeletal muscles have not been examined. This study aims to demonstrate the subcellular localization of MTA1 in skeletal muscles and reveal its possible roles in skeletal muscle pathogenesis. Striated muscles (skeletal and cardiac) from C57BL/6 mice of 4-5 weeks were collected to examine the expression of MTA1 by Western blotting and immunohistochemistry. Immunofluorescence and immunoelectron microscopy were performed for MTA1, α-actinin (a Z-disc marker protein), and SMN (survival of motor neuron) proteins. Gene Expression Omnibus (GEO) data sets were analyzed using the GEO2R online tool to explore the functional implications of MTA1 in skeletal muscles. MTA1 expression was detected by Western blotting and immunohistochemistry in skeletal and cardiac muscles. Subcellular localization of MTA1 was found in the Z-disc of sarcomeres, where α-actinin and SMN were expressed. Data mining of GEO profiles suggested that MTA1 dysregulation is associated with multiple skeletal muscle defects, such as Duchenne muscular dystrophy, Emery-Dreifuss muscular dystrophy, nemaline myopathy, and dermatomyositis. The GEO analysis also showed that MTA1 expression gradually decreased with age in mouse skeletal muscle precursor cells. The subcellular localization of MTA1 in sarcomeres of skeletal muscles implies its biological roles in sarcomere structures and its possible contribution to skeletal muscle pathology.

Silencing of circUSPL1 represses breast cancer progression by targeting miR-1296-5p/MTA1 axis.

The effect of circular RNAs (circRNAs) is widely studied in various human cancers, including breast cancer (BC). Herein, circUSPL1 has been recognized as a new regulator for BC progression. However, the detailed biological function and molecular mechanism of circUSPL1 in BC remain vague. The expression level of circUSPL1, miR-1296-5p and metastasis associated 1 (MTA1) was examined by quantitative reverse transcription PCR. BC cell proliferation, migration, invasion, apoptosis and aerobic glycolysis were analyzed by colony formation assay, 5-ethynyl-2'-deoxyuridine assay, wound healing assay, transwell assay, flow cytometry and glycolysis corresponding kits, respectively. The protein level of Bcl-2, Bax, HK2, GLUT1 and MTA1 was evaluated by western blot analysis. The relationship of miR-1296-5p and circUSPL1 or MTA1 was affirmed using dual-luciferase reporter or RIP assays. A murine xenograft model was conducted to analyze the tumor growth in vivo. CircUSPL1 and MTA1 expression level was increased, but miR-1296-5p was particularly reduced in BC tissues and cells. CircUSPL1 deficiency significantly inhibited BC cell proliferation, migration, invasion, glycolysis, and promoted cell apoptosis. In addition, circUSPL1 directly targeted miR-1296-5p, and downregulation of miR-1296-5p eliminated the inhibitory action of circUSPL1 knockdown. Additionally, overexpression of miR-1296-5p repressed cell malignant properties, while the suppressive effects were overturned by MTA1 elevation. Lastly, silencing of circUSPL1 inhibited tumor growth by sponging miR-1296-5p and regulating MTA1. CircUSPL1 deficiency repressed BC cell malignant phenotypes through reducing MTA1 via targeting miR-1296-5p, which might provide a theoretical basis for BC treatment.

RNAi Screen Identifies MTA1 as an Epigenetic Modifier of Differentiation Commitment in Human HSPCs

The molecular mechanisms regulating key fate decisions of hematopoietic stem cells (HSCs) remain incompletely understood. Here, we targeted global shRNA libraries to primary human hematopoietic stem and progenitor cells (HSPCs) to screen for modifiers of self-renewal and differentiation, and identified metastasis-associated 1 (MTA1) as a negative regulator of human HSPC propagation in vitro. Knockdown of MTA1 by independent shRNAs in primary human cord blood (CB) HSPCs led to a cell expansion during culture and a relative accumulation of immature CD34+CD90+ cells with perturbed in vitro differentiation potential. Transplantation experiments in immunodeficient mice revealed a significant reduction in human chimerism in both blood and bone marrow from HSPCs with knockdown of MTA1, possibly caused by reduced maturation of blood cells. We further found that MTA1 associates with the nucleosome remodeling deacetylase (NuRD) complex in human HSPCs, and on knockdown of MTA1, we observed an increase in H3K27Ac marks coupled with a downregulation of genes linked to differentiation toward the erythroid lineage. Together, our findings identify MTA1 as a novel regulator of human HSPCs in vitro and in vivo with critical functions for differentiation commitment.

Shikonin inhibits the proliferation of cervical cancer cells via FAK/AKT/GSK3β signalling.

Cervical cancer is one of the most lethal malignancies of the female reproductive system. Shikonin, a naphthoquinone pigment extracted from the traditional medicinal herb, Lithospermum erythrorhizon, has been demonstrated to exert significant inhibitory effects on a variety of tumours in vitro and in vivo. In the present study, the effects of shikonin on cervical cancer and the underlying mechanisms were investigated. The effects of shikonin on the viability on HeLa and SiHa cervical cancer cells was examined using cell counting kit (CCK-8) and colony formation assays. Immunofluorescence assay was performed to detect the levels of the proliferation-related protein, Ki67. Western blot analysis was utilized to measure the phosphorylated and total expression levels of proteins, including focal adhesion kinase (FAK), AKT, and glycogen synthase kinase 3β (GSK3β). Cell migration was determined by using wound healing assay. Metastasis-associated 1 (MTA1), TGFβ1 and VEGF mRNA expression levels were determined using reverse transcription-quantitative PCR. It was demonstrated that, shikonin inhibited cervical cancer cell proliferation and migration. The data of the present study revealed that shikonin inhibited the proliferation of HeLa and SiHa cells in a concentration- and time-dependent manner. Mechanistically, shikonin blocked the proliferation of cervical cancer cells by downregulating the phosphorylation of FAK, AKT and GSK3β induced by EGF. In addition, shikonin significantly suppressed cell migration and reduced the expression of migration-related proteins, including MTA1, TGFβ1 and VEGF. On the whole, the present study demonstrates that shikonin may exert an inhibitory effect on the cervical cancer cell proliferation and migration through the FAK/AKT/GSK3β signaling pathway. These findings suggest that shikonin may function as a potential therapeutic drug for the treatment of cervical cancer.

RUNX2 recruits the NuRD(MTA1)/CRL4B complex to promote breast cancer progression and bone metastasis

Runt-related transcription factor 2 (RUNX2) is an osteogenesis-related transcription factor that has emerged as a prominent transcription repressing factor in carcinogenesis. However, the role of RUNX2 in breast cancer metastasis remains poorly understood. Here, we show that RUNX2 recruits the metastasis-associated 1 (MTA1)/NuRD and the Cullin 4B (CUL4B)-Ring E3 ligase (CRL4B) complex to form a transcriptional-repressive complex, which catalyzes the histone deacetylation and ubiquitylation. Genome-wide analysis of the RUNX2/NuRD(MTA1)/CRL4B complex targets identified a cohort of genes including peroxisome proliferator-activated receptor alpha (PPARα) and superoxide dismutase 2 (SOD2), which are critically involved in cell growth, epithelial-to-mesenchymal transition (EMT) and invasion. We demonstrate that the RUNX2/NuRD(MTA1)/CRL4B complex promotes the proliferation, invasion, tumorigenesis, bone metastasis, cancer stemness of breast cancer in vitro and in vivo. Strikingly, RUNX2 expression is upregulated in multiple human carcinomas, including breast cancer. Our study suggests that RUNX2 is a promising potential target for the future treatment strategies of breast cancer.

RNA binding protein RALY activates the cholesterol synthesis pathway through an MTA1 splicing switch in hepatocellular carcinoma

Alternative splicing is an important RNA processing event that contributes to RNA complexity and protein diversity in cancer. Accumulating evidence demonstrates the essential roles of some alternatively spliced genes in carcinogenesis. However, the potential roles of alternatively spliced genes in hepatocellular carcinoma (HCC) are still largely unknown. Here we showed that the HnRNP Associated with Lethal Yellow Protein Homolog (RALY) gene is upregulated and associated with poor outcomes in HCC patients. RALY acts as a tumor-promoting factor by cooperating with splicing factor 3b subunit 3 (SF3B3) and modulating the splicing switch of Metastasis Associated 1 (MTA1) from MTA-S to MTA1-L. Normally, MTA1-S inhibits cell proliferation by reducing the transcription of cholesterol synthesis genes. In HCC, RALY and SF3B3 cooperate to regulate the MTA1 splicing switch, leading to a reduction in the MTA1-S level, and alleviating the inhibitory effect of MTA1-S on cholesterol synthesis genes, thus promoting HCC cell proliferation. In conclusion, our results revealed that the RALY-SF3B3/MTA1/cholesterol synthesis pathway contributes essentially to hepatic carcinogenesis and could serve as a promising therapeutic target for HCC.

In silico view of MTA1 biochemical signatures in breast malignancy for improvement in immunosurveillance

Metastasis Associated 1 (MTA1) chromatin modifier oncoprotein played a crucial role in both normal and genotoxic stress situations for genome maintenance. To investigates MTA1 regulatory pattern with drug resistance abilities in breast primary carcinoma to advanced invasive stages for identification of cancer adapting defense system. We design rationale in silico pipeline from data retrieval to analysis i.e. gene enrichment analysis performed by GeneCards Version 5.1: THE HUMAN GENE DATABASE (www.genecards.org), UALCAN database (www.ualcan.path.uab.edu) for analyzing MTA1 gene expression and promoter methylation in both breasts normal and cancerous tissue samples, cBioPortal for Cancer Genomics (www.cbioportal.org) database for MTA1 mutation analysis and finally analyzed MTA1 functional association with anticancer drugs in breast malignancy via online CCLE GDSC toolkit (www.public.tableau.com/CCLE_GDSC_Correlations). Our results revealed MTA1 overexpression aggressive behavior in stage II, stage III, TNBC-LAR, TNBC-M, TNBC-UNS, IDC, ILC, and post-menopause events of breast malignancy. MTA1 upregulation strongly promotes primary tumor transformation into invasive metastatic carcinoma by hijacking the host lymphatic system and cytokine signaling in both ductal and glandular breast cancers. MTA1 upregulation in the African-American population invites to design de novo model of cancer cell homeostasis under a reduced supply of vegetable nutrients, local-foreign stress, and replicative capacity for metastasis. MTA1 showed a hypomethylation profile that reflects regulatory strength under stress-mediated situations for higher events of transcription. In drug resistance analysis MTA1 has strong resistance towards 15 anti-cancer drugs that confirmed its previously reported behavior of genotoxic stress adaptation for metastasis. Our in silico evidence invites us to design a comprehensive strategy against MTA1 mediated stress managing proteome. In the future there is an urgent need to explore MTA1 shared stress coped protein networks for early diagnosis and better prognosis.

Expression of biomarkers vimentin and Metastasis Associated 1(MTA1) protein in different stages of laryngeal cancer and their impacts on survival

Expression of biomarkers vimentin and Metastasis Associated 1(MTA1) protein in different stages of laryngeal cancer and their impacts on survival

Expression of biomarkers vimentin and Metastasis Associated 1(MTA1) protein in different stages of laryngeal cancer and their impacts on survival

Laryngeal cancer is the second most common cancer after the lip and oral cavity cancer ofhead and neck region1. Laryngeal malignancy is the seventh most common malignancy in males in India. Total number of new laryngeal cancer and death from laryngeal cancer have been estimated 12410 and 3760 respectively in 20192. As per last survey available the number of new cases diagnosed and total number of deaths from laryngeal malignancy were 25,460 and 17,560 respectively in 2012 in India3 . The incidence of cancer larynx is 1.26-8.18 per 100,000 populations in different regions of India. Carcinoma larynx constitutes40% of all Head and Neck cancers. Squamous cell carcinoma constitutes 95% of all malignancies of larynx. Glottis being the most common subsite followed by supraglottis and the least common site is the subglottis. There is an increasing incidence rate of this malignancy among middle aged and elderly men and women throughout the world. Expression of Biomarkers at different stages of laryngeal cancers and their impact on survival can play a crucial role in future management of laryngeal malignancies. In spite of having different modalities of treatments like surgery, radiotherapy, chemoradiation, the prognosis of laryngeal malignancies is still poor. The most common adverse factor for laryngeal cancer has been found lymph node metastasis. The process of progression of LSCC is complex and difficult to know it completely. Despite multi-modality therapeutic advances in recent decades, improvements in overall survival and disease free survival is very less. In this study we emphasized the role of expression of biomarkers vimentin and metastasis associated 1(MTA1) protein in different stages of laryngeal cancer and their impacts on survival.

TGF-β-MTA1-SMAD7-SMAD3-SOX4-EZH2 Signaling Axis Promotes Viability, Migration, Invasion and EMT of Hepatocellular Carcinoma Cells.

IntroductionEnhancer of zeste homolog 2 (EZH2) is implicated in hepatocellular carcinoma (HCC), but whether transforming growth factor-β (TGF-β)-metastasis associated 1 (MTA1)-SMAD7-SMAD3-SRY-Box Transcription Factor 4 (SOX4)-EZH2 signaling axis, in which EZH2 participates, is also involved in HCC remained unknown.MethodsData on EZH2 expression in liver hepatocellular carcinoma (LIHC) and its relation with prognosis of HCC patients were predicted and analyzed using online databases. Following transfection with or without TGF-β1, HCC cell viability, migration and invasion were determined with MTT, Scratch and Transwell assays. Relative expressions of epithelial-to-mesenchymal transition (EMT)-related factors (N-Cadherin, Vimentin, and E-Cadherin) and TGF-β-MTA1-SMAD7-SMAD3-SOX4-EZH2 signaling axis factors (TGF-β, MTA1, SMAD7, phosphorylated-SMAD3, SOX4 and EZH2) were calculated via reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot.ResultsEZH2 was upregulated in HCC, which was related to poor prognosis. Silencing EZH2 suppressed EZH2 expression and HCC cell viability, migration, and invasion, and increased E-Cadherin expression yet decreased N-Cadherin and Vimentin expression, whereas EZH2 overexpression did conversely. Also, silencing EZH2 reversed the effects of TGF-β1 on promoting viability, migration, and invasion, as well as N-Cadherin and Vimentin expressions, yet suppressing E-Cadherin expression in HCC cells. In addition, TGF-β1 promoted TGF-β, MTA1, SOX4 and EZH2 expressions and p-SMAD3/SMAD3 ratio yet suppressed SMAD7, whereas silencing EZH2 solely reversed the effects of TGF-β1 on EZH2 expression in HCC cells.ConclusionThe present study provides a theoretical basis for TGF-β-MTA1-SMAD7-SMAD3-SOX4-EZH2 signaling cascade in viability, migration, invasion, and EMT of HCC cells. Inhibiting these signals may represent a therapeutic pathway for the treatment of metastatic HCC.

MTA1 Promotes Hepatocellular Carcinoma Progression by Downregulation of DNA-PK-Mediated H1.2T146 Phosphorylation.

Global incidence and mortality associated with hepatocellular carcinoma (HCC) is steadily increasing. Metastasis-associated 1 (MTA1) can induce tumorigenesis and metastatic progression in HCC. However, the mechanistic details of MTA1-mediated regulation of HCC has not been completely defined. Epigenetic histone modification is closely related to tumor development. Histone cluster 1 H1 family member c (H1.2) is important for epigenetic histone modification and chromatin remodeling; however, whether it has a role in HCC tumorigenesis is not known. In the current study, we confirmed that MTA1 promoted HCC cell growth and migration. Our results further show that MTA1 inhibited the phosphorylation of histone cluster 1 H1 family member c (H1.2) at threonine-146 residue (T146) (H1.2T146ph). MTA1 inhibited H1.2T146ph by mediating proteasomal degradation of the DNA protein kinase (DNA-PK). Pharmacological inhibition of proteasomal degradation of DNA-PK or genetic ablation of E3 ligase mouse double minute 2 (MDM2) rescued expression of DNA-PK, and subsequent phosphorylation of H1.2. MTA1's role in HCC was inhibited by ectopic expression of H1.2T146ph in HCC cell lines. Our results showed that H1.2T146ph can bind to MTA1 target genes. Collectively, our study confirms that MTA1 functions as an oncogene and promotes HCC progression. The epigenetic histone modifier H1.2T146ph exerts critical role in the regulation of MTA1-induced tumorigenesis. MTA1 regulates posttranslational activation of H1.2 by regulating the cognate kinase, DNA-PK, via the ubiquitin proteasome system. MTA1 expression was inversely correlated to both DNA-PK and phosphorylated H1.2 in HCC tissue specimens compared to tumor adjacent normal hepatic tissue, revealing that the MTA1/MDM2/DNA-PK/H1.2 is an important therapeutic axis in HCC.

RNA-INTERFERENCE SCREEN IDENTIFIES MTA1 AS A REGULATOR OF HUMAN HEMATOPOIETIC STEM AND PROGENITOR CELLS

The hematopoietic stem cell (HSC) is arguably one of the most well studied adult stem cells, however, the regulatory mechanisms that govern HSC fate are still not fully understood. In order to identify novel genetic regulators of HSC function, we used a near-genome wide RNA-interference (RNAi) lentivirus library to target primary human hematopoietic stem and progenitor cells (HSPCs). Among other candidates, we identified metastasis-associated 1 (MTA1) as a negative regulator of human HSPC propagation in vitro. MTA1 is part of the nucleosome remodeling deacetylase (NuRD) complex, a pan-cellular transcriptional repression complex, similar to other chromatin remodelers like SWI/SNF and the Polycomb complexes. Upon knockdown of MTA1 by independent shRNAs in primary human cord blood CD34+ cells, we observed an increased cell expansion during culture and a relative accumulation of immature CD34+CD90+ cells compared to control. By contrast, the colony forming potential was reduced, indicating perturbed differentiation and ability to form mature blood cells. Furthermore, transplantation experiments in immunodeficient mice showed a significant reduction of human chimerism in both blood and bone marrow from HSPCs with knockdown of MTA1. These findings suggest that MTA1 regulates the balance between renewal and differentiation of human HSPCs, as well as their in vivo engraftment potential. To gain more molecular insights we performed global transcriptional profiling and found a strong downregulation of essential genes related to cell engraftment and adhesion, including CXCR4, which might, at least in part, explain the engraftment defect seen upon MTA1 knockdown. Current studies are aimed at exploring the interaction between MTA1 and other NuRD complex members, such as CHD4, and how their interplay regulates transcriptional programs involved in human HSC biology.

Effect of metformin on the proliferation, apoptosis, invasion and autophagy of ovarian cancer cells.

The present study evaluated the effect of metformin on the SKOV3 ovarian cancer cell line and investigated the underlying mechanism. The inhibitory rate of SKOV3 cells was analyzed by MTT assay. SKOV3 cell apoptosis rate was quantitatively measured using flow cytometry. The effect of metformin on intracellular autophagosomes was observed using electron microscopy. The migration and invasion capabilities of SKOV3 cells were assessed by cell scratch test and Transwell assay. Results demonstrated that. the proliferation rate of SKOV3 cells was significantly inhibited in a time- and concentration-dependent manner following treatment with different concentrations of metformin for 24, 48 and 72 h. The number of migratory cells significantly decreased with increasing concentrations of metformin. The administration of metformin also promoted autophagy of ovarian cancer The expression level of microtubule associated protein 1 light chain 3-α protein was markedly upregulated. The mRNA expression level of metastasis-associated 1 (MTA1) was significantly downregulated following metformin treatment. In conclusion, metformin intervention suppressed SKOV3 proliferation and induced apoptosis in a concentration-dependent manner. Metformin also inhibited the invasion and migration of SKOV3 cells. It was hypothesized that the underlying mechanism of metformin's effect may involve MTA1 downregulation.

Hsa_circ_0039411 promotes tumorigenesis and progression of papillary thyroid cancer by miR-1179/ABCA9 and miR-1205/MTA1 signaling pathways.

Papillary thyroid cancer (PTC) is a common malignancy in endocrine system worldwide. Increasing evidence has shown that dysregulation of circular RNAs (circRNAs) could contribute to PTC tumorigenesis. The aims of this project are to investigate the potential role and molecular mechanism of hsa_circ_0039411 in PTC. In the project, RT-qPCR was performed to measure the expression profile of hsa_circ_0039411 in PTC tissues and cells. Cell counting kit-8, clonogenic, flow cytometric, and transwell experiments were used to identify the biological role of hsa_circ_0039411 on PTC cell progression. Bioinformatics methods, along with the dual-luciferase reporter test, was used to identify the potential mechanism of hsa_circ_0039411. Hsa_circ_0039411 was identified as enhanced in PTC tissues/cells. Gain-of-function experiments indicated that hsa_circ_0039411 facilitated PTC cell growth, migration, and invasion and inhibited cell apoptosis. Knockdown of hsa_circ_0039411 caused the opposite effects mentioned above. The mechanism exploration showed that hsa_circ_0039411 functioned as a sponge for miR-1179 and miR-1205 to elevate ATP-binding cassette transporter A9 (ABCA9) and metastasis-associated 1 (MTA1) expression at the post-transcriptional level, respectively. Further investigation confirmed that the functions of hsa_circ_0039411 are dependent on its modulation of ABCA9 and MTA1 in PTC cells. This study uncovered a mechanism of hsa_circ_0039411 in PTC, which might act as a novel therapeutic target for PTC.

Interleukin-17 Promotes Migration and Invasion of Human Cancer Cells Through Upregulation of MTA1 Expression.

Interleukin-17 (IL-17) has been shown to promote development of prostate, colon, skin, lung, breast, and pancreatic cancer. The purpose of this study was to determine if IL-17 regulates MTA1 expression and its biological consequences. Human cervical cancer HeLa and human prostate cancer DU-145 cell lines were used to test if IL-17 regulates metastasis associated 1 (MTA1) mRNA and protein expression using quantitative reverse transcription-polymerase chain reaction and Western blot analysis, respectively. Cell migration and invasion were studied using wound healing assays and invasion chamber assays. Thirty-four human cervical tissues were stained for IL-17 and MTA1 using immunohistochemical staining. We found that IL-17 increased MTA1 mRNA and protein expression in both cell lines. Cell migration was accelerated by IL-17, which was abolished by knockdown of MTA1 expression with small interference RNA (siRNA). Further, cell invasion was enhanced by IL-17, which was eliminated by MTA1 knockdown. Human cervical intra-epithelial neoplasia (CIN) and cervical cancer tissues had increased number of IL-17-positive cells and MTA1 expression compared to normal cervical tissues. The number of IL-17-positive cells was positively correlated with MTA1 expression. These findings demonstrate that IL-17 upregulates MTA1 mRNA and protein expression to promote HeLa and DU-145 cell migration and invasion.

Expression of vimentin (VIM) and metastasis-associated 1 (MTA1) protein in laryngeal squamous cell carcinoma are associated with prognostic outcome of patients.

Laryngeal squamous cell carcinoma (LSCC), a common type of head and neck cancer, is associated with high rates of metastasis and recurrence. In this study, we investigated the potential combinatorial prognostic value of NOTCH1, Vimentin (VIM), and Metastasis-associated 1 (MTA1) protein in LSCC, using immunohistochemistry. Tissue specimens from 69 patients with LSCC were immunohistochemically evaluated for the protein expression of NOTCH1, VIM, and MTA1. Then, biostatistical analysis was performed, in order to assess the prognostic value of the expression of each one of these proteins. NOTCH1 expression status was not a significant prognosticator in LSCC, as shown in Kaplan-Meier survival analysis. On the contrary, both VIM and MTA1 seem to have an important prognostic potential, independently of TNM staging and histological grade of the tumor. In fact, positive VIM expression was shown to predict patients' relapse and poor outcome regarding patients' overall survival, in contrast with MTA1, the positive expression of which predicts higher disease-free survival (DFS) and overall survival (OS) rates in LSCC. VIM and MTA1 constitute potential tumor biomarkers in LSCC and could be integrated into a multiparametric prognostic model. Undoubtedly, their prognostic value needs further validation in larger cohorts of LSCC patients.

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

BackgroundThis 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/MethodsHuman 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-α (HIF-1α), and vascular endothelial growth factor (VEGF).ResultsMTA1 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-1α and VEGF, which were down-regulated by MTA1 silencing.ConclusionsMTA1 gene expression promoted angiogenesis in mouse xenografts from human NSCLC cells.

Silence of α1-Antitrypsin Inhibits Migration and Proliferation of Triple Negative Breast Cancer Cells.

Backgroundα1-antitrypsin (α1-AT) is highly expressed in many tumors. However, to the best of our knowledge, its relationship to triple negative breast cancer (TNBC) has not yet been studied. Thus, in this research we first explored the influence of α1-AT silencing on the abilities of migration and invasion, and then further study its molecular mechanism in TNBC cells.Material/MethodsThe viability of MDA-MB-231 cells were detected using cell counting kit-8 (CCK-8). The abilities of migration and invasion were examined by Transwell assay. The metastasis-related factors were tested respectively by quantitative real-time PCR (qRT-PCR) and western blot assays.ResultsOur study results showed that α1-AT level in TNBC tissues was higher than non-triple negative breast cancer (n-TNBC) and adjacent normal breast tissues. The high expression of α1-AT was linked to type of cancer, tumor size, TNM stage and metastasis, but was not correlated with α1-AT expression and age. si-α1-AT suppressed the viability, migration, and invasion of cells. While si-α1-AT upregulated E-cadherin and the tissue inhibitor of metalloproteinases-2 (TIMP-2) levels, it downregulated metastasis associated 1 (MTA1), matrix metallopeptidase 2 (MMP2), phosphorylated-mammalian target of rapamycin (p-mTOR), phosphorylated-protein kinase B (p-Akt), and phosphorylated-phosphatidylinositol 3 kinase (p-PI3K) levels. We also found that the PI3K/Akt/mTOR pathway activator reversed the role of si-α1-AT in metastasis-related factors.Conclusionsα1-AT was highly expressed in TNBC tissues, and its silencing suppressed the abilities of migration and invasion in TNBC cells and downregulated the PI3K/Akt/mTOR pathway. Thus, α1-AT may have a potential therapeutic effect on TNBC.