Bidirectional autoregulatory mechanism of metastasis-associated protein 1-alternative reading frame pathway in oncogenesis

MTA1: A Vital Modulator in Prostate Cancer

Prostate cancer (PCa) is the most frequent cancer of the male genitourinary system and the second most common cancer in men worldwide. PCa has become one of the leading diseases endangering men's health in Asia in recent years, with a large increase in morbidity and mortality. MTA1 (metastasis-associated antigen-1), a transcriptional coregulator involved in histone deacetylation and nucleosome remodeling, is a member of the MTA family. MTA1 is involved in cell signaling, chromosomal remodeling, and transcriptional activities, all of which are important for epithelial cell progression, invasion, and growth. MTA1 has been demonstrated to play a significant role in the formation, progression, and metastasis of PCa, and MTA1 expression is specifically linked to PCa bone metastases. Therefore, MTA1 may be a potential target for PCa prevention and treatment. Here, we reviewed the structure, function, and expression of MTA1 in PCa as well as drugs that target MTA1 to highlight a potential new treatment for PCa.

Inhibition of the invasion and metastasis of mammary carcinoma cells by NBD peptide targeting S100A4 via the suppression of the Sp1/MMP‑14 axis

A synthetic peptide that blocks the interaction between the metastasis‑enhancing calcium‑binding protein, S100A4, and its effector protein, methionine aminopeptidase 2 (MetAP2) (the NBD peptide), was previously demonstrated to inhibit the angiogenesis of endothelial cells, leading to the regression of human prostate cancer in a xenograft model. However, the effects of the NBD peptide on the malignant properties of cancer cells that express S100A4 remain to be elucidated. The present study demonstrates that the NBD peptide inhibits the invasiveness and metastasis of highly metastatic human mammary carcinoma cells. The introduction of the peptide into MDA‑MB‑231 variant cells resulted in the suppression of matrix degradation in a gelatin invadopodia assay and invasiveness in a Matrigel invasion assay. In line with these results, the peptide significantly downregulated the expression of matrix metalloproteinase (MMP)‑14 (MT1‑MMP). Mechanistic analysis of the downregulation of MMP‑14 revealed the suppression of the expression of the transcription factor, specificity protein 1 (Sp1), but not that of nuclear factor (NF)‑κB, early growth response 1 (EGR1) or ELK3, all of which were reported to be involved in transcriptional regulation of the MMP‑14 gene. At the same time, evidence suggested that the NBD peptide also suppressed Sp1 and MMP‑14 expression levels in MDA‑MB‑468 cells. Importantly, the intravenous administration of the NBD peptide encapsulated in liposomes inhibited pulmonary metastasis from mammary gland tumors in mice with xenograft tumors. These results indicate that the NBD peptide can suppress malignant tumor growth through the suppression of the Sp1/MMP‑14 axis. Taken together, these results reveal that the NBD peptide acts on not only endothelial cells, but also on tumor cells in an integrated manner, suggesting that the peptide may prove to be a promising cancer therapeutic peptide drug.

Isocitrate dehydrogenase 3A, a rate-limiting enzyme of the TCA cycle, promotes hepatocellular carcinoma migration and invasion through regulation of MTA1, a core component of the NuRD complex

The precise molecular mechanism of hepatocellular carcinoma (HCC) remains ambiguous. Isocitrate dehydrogenase 3A (IDH3A) is known as a subunit of the IDH3 heterotetramer. To the best of our knowledge, the biological effect of IDH3A in malignant tumors is unclear. Here, we report that IDH3A is significantly upregulated in HCC tissues; moreover, high expression of IDH3A is strongly associated with tumor size and the clinicopathologic stage of HCC. RNA-seq revealed that depletion of IDH3A affects the expression of metastasis associated 1 (MTA1), an oncogene which is related to the progression of numerous cancer types to the metastasis stage. Cell transfection was used to upregulate and downregulate the expression of IDH3A in HCC cells. The migration activity of HCC cells was assessed using wound healing assays. While transwell assays were carried out to detect the invasion of HCC cells. RNA-seq, RT-qPCR and western blot were used to validate MTA1 as a potential target gene. The present study suggested that IDH3A can upregulate MTA1 expression and promote epithelial-mesenchymal transition (EMT) in HCC by inducing MTA1 expression, thereby facilitating cell migration and invasion of HCC cells. Here, we demonstrated the importance of IDH3A in HCC progression. The identification of the IDH3A axis provides novel insight into the pathogenesis of HCC, and the IDH3A axis might represent a novel target for the treatment of HCC.

A TGF-β-MTA1-SOX4-EZH2 signaling axis drives epithelial-mesenchymal transition in tumor metastasis

MTA1, SOX4, EZH2, and TGF-β are all potent inducers of epithelial-mesenchymal transition (EMT) in cancer; however, the signaling relationship among these molecules in EMT is poorly understood. Here, we investigated the function of MTA1 in cancer cells and demonstrated that MTA1 overexpression efficiently activates EMT. This activation resulted in a significant increase in the migratory and invasive properties of three different cancer cell lines through a common mechanism involving SOX4 activation, screened from a gene expression profiling analysis. We showed that both SOX4 and MTA1 are induced by TGF-β and both are indispensable for TGF-β-mediated EMT. Further investigation identified that MTA1 acts upstream of SOX4 in the TGF-β pathway, emphasizing a TGF-β-MTA1-SOX4 signaling axis in EMT induction. The histone methyltransferase EZH2, a component of the polycomb (PcG) repressive complex 2 (PRC2), was identified as a critical responsive gene of the TGF-β-MTA1-SOX4 signaling in three different epithelial cancer cell lines, suggesting that this signaling acts broadly in cancer cells in vitro. The MTA1-SOX4-EZH2 signaling cascade was further verified in TCGA pan-cancer patient samples and in a colon cancer cDNA microarray, and activation of genes in this signaling pathway predicted an unfavorable prognosis in colon cancer patients. Collectively, our data uncover a SOX4-dependent EMT-inducing mechanism underlying MTA1-driven cancer metastasis and suggest a widespread TGF-β-MTA1-SOX4-EZH2 signaling axis that drives EMT in various cancers. We propose that this signaling may be used as a common therapeutic target to control epithelial cancer metastasis.

Hyperinsulinemia-induced KLF5 mediates endothelial angiogenic dysfunction in diabetic endothelial cells

Reduced expression of endothelial nitric oxide synthase (eNOS) is a hallmark of endothelial dysfunction in diabetes, which predisposes diabetic patients to numerous cardiovascular complications including blunted angiogenesis. The Krüppel-like factor (KLF) five has been implicated as a central regulator of cardiovascular remodeling, but its role in endothelial cells (ECs) remains poorly understood. We show here that expression of endothelial KLF5 was significantly increased in the ECs from mouse diabetes mellitus type 2 (T2DM) model, when compared to non-diabetic or T1DM mouse. KLF5 up-regulation by insulin was dependent on activation of multiple pathways, including mammalian target of rapamycin, oxidative stress and Protein kinase C pathways. Hyperinsulinemia-induced KLF5 inhibited endothelial function and migration, and thereby compromised in vitro and in vivo angiogenesis. Mechanistically, KLF5 acted in concert with the MTA1 coregulator to negatively regulate NOS3 transcription, thereby leading to the diminished eNOS levels in ECs. Conversely, potentiation of cGMP content (the essential downstream effector of eNOS signaling) by pharmacological approaches successfully rescued the endothelial proliferation and in vitro tube formation, in the HUVECs overexpressing the exogenous KLF5. Collectively, the available data suggest that the augmentation of endothelial KLF5 expression by hyperinsulinemia may represent a novel mechanism for negatively regulating eNOS expression, and may thus help to explain for the T2DM-related endothelial dysfunction at the transcriptional level.

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.

RBR-type E3 ubiquitin ligase RNF144A targets PARP1 for ubiquitin-dependent degradation and regulates PARP inhibitor sensitivity in breast cancer cells

Poly(ADP-ribose) polymerase 1 (PARP1), a critical DNA repair protein, is frequently upregulated in breast tumors with a key role in breast cancer progression. Consequently, PARP inhibitors have emerged as promising therapeutics for breast cancers with DNA repair deficiencies. However, relatively little is known about the regulatory mechanism of PARP1 expression and the determinants of PARP inhibitor sensitivity in breast cancer cells. Here, we report that ring finger protein 144A (RNF144A), a RING-between-RING (RBR)-type E3 ubiquitin ligase with an unexplored functional role in human cancers, interacts with PARP1 through its carboxy-terminal region containing the transmembrane domain, and targets PARP1 for ubiquitination and subsequent proteasomal degradation. Moreover, induced expression of RNF144A decreases PARP1 protein levels and renders breast cancer cells resistant to the clinical-grade PARP inhibitor olaparib. Conversely, knockdown of endogenous RNF144A increases PARP1 protein levels and enhances cellular sensitivity to olaparib. Together, these findings define RNF144A as a novel regulator of PARP1 protein abundance and a potential determinant of PARP inhibitor sensitivity in breast cancer cells, which may eventually guide the optimal use of PARP inhibitors in the clinic.

Chromatin remodeling protein MORC2 promotes breast cancer invasion and metastasis through a PRD domain-mediated interaction with CTNND1

MORC family CW-type zinc finger 2 (MORC2) is a newly identified chromatin remodeling protein with emerging roles in the regulation of DNA damage response and gene transcription, but its mechanistic role in breast cancer development and progression remains unexplored. Here, we show that MORC2 promoted breast cancer invasion and metastasis and these effects depended on a proline-rich domain (PRD) within its carboxy-terminal region spanning residues 601–734. Induced expression of wild-type MORC2 did not significantly affect cell proliferation and cell-cycle progression, but promoted breast cancer cell migration and invasion in vitro and metastatic lung colonization in vivo. The PRD domain was dispensable for the protein stability and subcellular localization of MORC2, but depletion of the PRD domain substantially suppressed MORC2-mediated migration, invasion, and metastasis. Proteomic and biochemical analyses further demonstrated that wild-type MORC2, but not PRD deletion mutant, interacted with catenin delta 1 (CTNND1), a cadherin-associated protein that participates in tumor invasion and metastasis. Moreover, knockdown of endogenous CTNND1 by short hairpin RNAs suppressed the migratory and invasive potential of MORC2-expressing cells. Taken together, these results suggest that MORC2 promotes breast cancer invasion and metastasis through its PRD domain-mediated interaction with CTNND1.

Stimulation of ribosomal RNA gene promoter by transcription factor Sp1 involves active DNA demethylation by Gadd45-NER pathway

The well-studied Pol II transcription factor Sp1 has not been investigated for its regulatory role in rDNA transcription. Here, we show that Sp1 bound to specific sites on rDNA and localized into the nucleoli during the G1 phase of cell cycle to activate rDNA transcription. It facilitated the recruitment of Pol I pre-initiation complex and impeded the binding of nucleolar remodeling complex (NoRC) to rDNA resulting in the formation of euchromatin active state. More importantly, Sp1 also orchestrated the site-specific binding of Gadd45a-nucleotide excision repair (NER) complex resulting in active demethylation and transcriptional activation of rDNA. Interestingly, knockdown of Sp1 impaired rDNA transcription due to reduced engagement of the Gadd45a-NER complex and hypermethylation of rDNA. Thus, the present study unveils a novel role of Sp1 in rDNA transcription involving promoter demethylation.

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.

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.

ATP-dependent chromatin remodeling complexes as novel targets for cancer therapy

The progression to advanced stage cancer requires changes in many characteristics of a cell. These changes are usually initiated through spontaneous mutation. As a result of these mutations, gene expression is almost invariably altered allowing the cell to acquire tumor-promoting characteristics. These abnormal gene expression patterns are in part enabled by the posttranslational modification and remodeling of nucleosomes in chromatin. These chromatin modifications are established by a functionally diverse family of enzymes including histone and DNA-modifying complexes, histone deposition pathways, and chromatin remodeling complexes. Because the modifications these enzymes deposit are essential for maintaining tumor-promoting gene expression, they have recently attracted much interest as novel therapeutic targets. One class of enzyme that has not generated much interest is the chromatin remodeling complexes. In this review, we will present evidence from the literature that these enzymes have both causal and enabling roles in the transition to advanced stage cancers; as such, they should be seriously considered as high-value therapeutic targets. Previously published strategies for discovering small molecule regulators to these complexes are described. We close with thoughts on future research, the field should perform to further develop this potentially novel class of therapeutic target.

Subcellular localization of MTA proteins in normal and cancer cells

The subcellular localization of a protein is closely linked to and indicates its function. The metastatic tumor antigen (MTA) family has been under continuous investigation since its identification two decades ago. MTA1, MTA2, and MTA3 are the main members of the MTA family. MTA1, as the representative member of this family, has been shown to be widely expressed in both embryonic and adult tissues, as well as in normal and cancerous conditions, indicating that MTA1 has functions both in physiological and pathological contexts. MTA1 is expressed at a higher level in most cancers than in their normal tissue counterparts. Even in normal cells, MTA1 levels vary a great deal from tissue to tissue. Importantly, MTA1 shows a multiple localization pattern in the cell, as do MTA2 and MTA3. Different MTA components in different subcellular compartments may exert different molecular functions in the cell. Previous studies revealed that MTA1 and MTA2 are predominately localized to the nucleus, while MTA3 is observed in both the nucleus and cytoplasm. Recent studies have reported that MTA1 is located in the nucleus, cytoplasm, and the nuclear envelope. In the nucleus, MTA1 dynamically interacts with chromatin in a MTA1-K532 methylation-dependent manner, whereas cytoplasmic MTA1 binds to the microtubule skeleton. MTA1 also shows a dynamic distribution during the cell cycle. Further investigations are needed to identify the exact subcellular localizations of MTA proteins. We review the sub-cellular localization patterns of the MTA family members and give a comprehensive overview of their respective molecular activities in multiple contexts.

Resistin promotes the expression of vascular endothelial growth factor in ovary carcinoma cells

Resistin is a novel hormone that is secreted by human adipocytes and mononuclear cells and is associated with obesity, insulin resistance and inflammation. Recently, resistin has been postulated to play a role in angiogenesis. Here, we investigated the hypothesis that resistin regulates ovary carcinoma production of vascular endothelial growth factor (VEGF) and the angiogenic processes. We found that in human ovarian epithelial carcinoma cells (HO-8910), resistin (10–150 ng/mL) enhanced both VEGF protein and mRNA expression in a time- and concentration-dependent manner, as well as promoter activity. Furthermore, resistin enhanced DNA-binding activity of Sp1 with VEGF promoter in a PI3K/Akt-dependent manner. PI3K/Akt activated by resistin led to increasing interaction with Sp1, triggering a progressive phosphorylation of Sp1 on Thr453 and Thr739, resulting in the upregulation of VEGF expression. In an in vitro angiogenesis system for endothelial cells (EA.hy926) co-cultured with HO-8910 cells, we observed that the addition of resistin stimulated endothelial cell tube formation, which could be abolished by VEGF neutralizing antibody. Our findings suggest that the PI3K/Akt-Sp1 pathway is involved in resistin-induced VEGF expression in HO-8910 cells and indicates that antiangiogenesis therapy may be beneficial treatment against ovarian epithelial carcinoma, especially in obese patients.

MTA1 promotes STAT3 transcription and pulmonary metastasis in breast cancer

Overexpression of the prometastatic chromatin modifier protein metastasis tumor antigen 1 (MTA1) in human cancer contributes to tumor aggressiveness, but the role of endogenous MTA1 in cancer has not been explored. Here, we report the effects of selective genetic depletion of MTA1 in a physiologically relevant spontaneous mouse model of breast cancer pulmonary metastasis. We found that MTA1 acts as a mandatory modifier of breast-to-lung metastasis without effects on primary tumor formation. The underlying mechanism involved MTA1-dependent stimulation of STAT3 transcription through action on the MTA1/STAT3/Pol II coactivator complex, and, in turn, on the expression and functions of STAT3 target genes including Twist1. Accordingly, we documented a positive correlation between levels of MTA1 and STAT3 in publicly available breast cancer data sets. Together, our findings reveal an essential modifying role of the physiologic level of MTA1 in supporting pulmonary metastasis of breast cancer.

Metastasis-associated protein 1 is an integral component of the circadian molecular machinery

The mammalian circadian clock regulates the daily cycles of many important physiological processes, but its mechanism is not well understood. Here we provide genetic and biochemical evidence that metastasis-associated protein 1 (MTA1), a widely upregulated gene product in human cancers, is an integral component of the circadian molecular machinery. Knockout of MTA1 in mice disrupts the free-running period of circadian rhythms under constant light and normal entrainment of behaviour to 12-h-light/12-h-dark cycles. The CLOCK-BMAL1 heterodimer activates MTA1 transcription through a conserved E-box element at its promoter. MTA1, in turn, interacts with and recruits CLOCK-BMAL1 at its own and CRY1 promoters and promotes their transcription. Moreover, MTA1 deacetylates BMAL1 at lysine 538 through regulating deacetylase SIRT1 expression, thus disturbing the CRY1-mediated negative feedback loop. These findings uncover a previously unappreciated role for MTA1 in maintenance of circadian rhythmicity through acting on the positive limb of the clock machinery.

p21-activated kinase-1 signaling regulates transcription of tissue factor and tissue factor pathway inhibitor

Tissue factor (TF) is a cell-surface glycoprotein responsible for initiating the coagulation cascade. Besides its role in homeostasis, studies have shown the implication of TF in embryonic development, cancer-related events, and inflammation via coagulation-dependent and -independent (signaling) mechanisms. Tissue factor pathway inhibitor (TFPI) plays an important role in regulating TF-initiated blood coagulation. Therefore, transcriptional regulation of TF expression and its physiological inhibitor TFPI would allow us to understand the critical step that controls many different processes. From a gene profiling study aimed at identifying differentially regulated genes between wild-type (WT) and p21-activated kinase 1-null (PAK1-KO) mouse embryonic fibroblasts (MEFs), we found TF and TFPI are differentially expressed in the PAK1-KO MEFs in comparison with wild-type MEFs. Based on these findings, we further investigated in this study the transcriptional regulation of TF and TFPI by PAK1, a serine/threonine kinase. We found that the PAK1·c-Jun complex stimulates the transcription of TF and consequently its procoagulant activity. Moreover, PAK1 negatively regulates the expression of TFPI and additionally contributes to increased TF activity. For the first time, this study implicates PAK1 in coagulation processes, through its dual transcriptional regulation of TF and its inhibitor.

Metastasis-associated protein 1 drives tumor cell migration and invasion through transcriptional repression of RING finger protein 144A

Metastasis-associated protein 1 (MTA1), a component of the nucleosome-remodeling and histone deacetylase complex, is widely up-regulated in human cancers and significantly correlated with tumor invasion and metastasis, but the mechanisms involved remain largely unknown. Here, we report that MTA1 transcriptionally represses the expression of RING finger protein 144A (RNF144A), an uncharacterized gene whose protein product possesses potential E3 ubiquitin ligase activity, by recruiting the histone deacetylase 2 (HDAC2) and CCAAT/enhancer-binding protein α (c/EBPα) co-repressor complex onto human RNF144A promoter. Furthermore, an inverse correlation between the expression levels of MTA1 and RNF144A was demonstrated in publicly available breast cancer microarray datasets and the MCF10 breast cancer progression model system. To address functional aspects of MTA1 regulation of RNF144A, we demonstrate that RNF144A is a novel suppressor of cancer migration and invasion, two requisite steps of metastasis in vivo, and knockdown of endogenous RNF144A by small interfering RNAs accelerates the migration and invasion of MTA1-overexpressing cells. These results suggest that RNF144A is partially responsible for MTA1-mediated migration and invasion and that MTA1 overexpression in highly metastatic cancer cells drives cell migration and invasion by, at least in part, interfering with the suppressive function of RNF144A through transcriptional repression of RNF144A expression. Together, these findings provide novel mechanistic insights into regulation of tumor progression and metastasis by MTA1 and highlight a previously unrecognized role of RNF144A in MTA1-driven cancer cell migration and invasion.

Low-power laser irradiation (LPLI) promotes VEGF expression and vascular endothelial cell proliferation through the activation of ERK/Sp1 pathway

Angiogenesis, the growth of new blood vessels from pre-existing vessels, represents an excellent therapeutic target for the treatment of wound healing and cardiovascular disease. Herein, we report that LPLI (low-power laser irradiation) activates ERK/Sp1 (extracellular signal-regulated kinase/specificity protein 1) pathway to promote VEGF expression and vascular endothelial cell proliferation. We demonstrate for the first time that LPLI enhances DNA-binding and transactivation activity of Sp1 on VEGF promoter in vascular endothelial cells. Moreover, Sp1-regulated transcription is in an ERK-dependent manner. Activated ERK by LPLI translocates from cytoplasm to nuclear and leads to increasing interaction with Sp1, triggering a progressive phosphorylation of Sp1 on Thr453 and Thr739, resulting in the upregulation of VEGF expression. Furthermore, selective inhibition of Sp1 by mithramycin-A or shRNA suppresses the promotion effect of LPLI on cell cycle progression and proliferation, which is also significantly abolished by inhibition of ERK activity. These findings highlight the important roles of ERK/Sp1 pathway in angiogenesis, supplying potential strategy for angiogenesis-related diseases with LPLI treatment.

Metastasis-associated protein 1/nucleosome remodeling and histone deacetylase complex in cancer

Cancer cells frequently exhibit deregulation of coregulatory molecules to drive the process of growth and metastasis. One such group of ubiquitously expressed coregulators is the metastasis-associated protein (MTA) family, a critical component of the nucleosome remodeling and histone deacetylase (NuRD) complex. MTA1 occupies a special place in cancer biology because of its dual corepressor or coactivator nature and widespread overexpression in human cancers. Here, we highlight recent advances in our understanding of the vital roles of MTA1 on transformation, epithelial-mesenchymal transition, and the functions of key cancer-relevant molecules such as a nexus of multiple oncogenes and tumor suppressors. In addition to its paramount role in oncogenesis, we reveal several new physiologic functions of MTA1 related to DNA damage, inflammatory responses, and infection, in which MTA1 functions as a permissive "gate keeper" for cancer-causing parasites. Further, these discoveries unraveled the versatile multidimensional modes of action of MTA1, which are independent of the NuRD complex and/or transcription. Given the emerging roles of MTA1 in DNA repair, inflammation, and parasitism, we discuss the possibility of MTA1-targeted therapy for use not only in combating cancer but also in other inflammation and pathogen-driven pathologic conditions.

IDIBELL Cancer Conference on Metastasis and Angiogenesis

The IDIBELL Cancer Conference (ICC) on Metastasis and Angiogenesis was held in Barcelona, Spain, on May 26–27, 2011. The program content was developed by Dr. Manel Esteller, director of the Cancer Epigenetics and Biology Program (PEBC-IDIBELL), Dr. Oriol Casanovas and Dr. Francesc Viñals Canals of the Catalan Institute of Oncology (ICO-IDIBELL), and Dr. Danny R. Welch from the University of Kansas Cancer Center. The topics discussed during the meeting included the latest advances in epigenetic control of metastasis and tumor cell invasion, and molecular mechanisms of angiogenesis and tumoral angiogenesis, and were presented by invited keynote speakers. One issue that recurred throughout the meeting was the increased appreciation of tumor–stromal/microenvironment interactions and how the tumor cells respond to these signals in the cancer dissemination process. Cancer Res; 71(19); 6097–101. ©2011 AACR.