Role of MTA2 in human cancer

Reengineering of Donor-Acceptor-Donor Structured Near-Infrared II Aggregation-Induced Emission Luminogens for Starving-Photothermal Antitumor and Inhibition of Lung Metastasis

Electron acceptor possessing strong electron-withdrawing ability and exceptional stability is crucial for developing donor-acceptor-donor (D-A-D) structured aggregation-induced emission luminogens (AIEgens) with second near-infrared (NIR-II) emission. Although 6,7-diphenyl-[1,2,5] thiadiazolo [3,4-g] quinoxaline (PTQ) and benzobisthiadiazole (BBT) are widely employed as NIR-II building blocks, they still suffer from limited electron-withdrawing capacity or inadequate chemo-stability under alkaline conditions. Herein, a boron difluoride formazanate (BFF) acceptor is utilized to construct NIR-II AIEgen, which exhibits a better overall performance in terms of NIR-II emission and chemo-stability compared to the PTQ- and BBT-derived fluorophores. With finely tuned intramolecular motions and strong D-A interaction strength, TPE-BFF simultaneously exhibits high molar extinction coefficient (ε= 4.31 × 104 M-1cm-1), strong NIR-II emission (Φ = 0.49%) and photothermal effect (η = 58.5%), as well as high stability. Thanks to these merits, the thermosensitive nanoparticles constructed by integrating TPE-BFF and the antiglycolytic agent 2-deoxy-d-glucose (2DG) are successfully utilized for imaging-guided photothermal antitumor lung metastasis by regulating glycolysis and reducing ATP-dependent heat shock proteins. Combining experimental results and theoretical calculations, BFF proves to be an outstanding electron acceptor for the design of versatile NIR-II AIEgens. Overall, this study offers a promising alternative for developing multifunctional NIR-II AIEgens in biomedical applications.

MTA2 knockdown suppresses human osteosarcoma metastasis by inhibiting uPA expression

The relationship between metastasis-associated protein 2 (MTA2) overexpression and tumor growth and metastasis has been extensively studied in a variety of tumor cells but not in human osteosarcoma cells. This study aims to elucidate the clinical significance, underlying molecular mechanisms, and biological functions of MTA2 in human osteosarcoma in vitro and in vivo. Our results show that MTA2 was elevated in osteosarcoma cell lines and osteosarcoma tissues and was associated with tumor stage and overall survival of osteosarcoma patients. Knockdown of MTA2 inhibited osteosarcoma cell migration and invasion by reducing the expression of urokinase-type plasminogen activator (uPA). Bioinformatic analysis demonstrated that high levels of uPA in human osteosarcoma tissues correlated positively with MTA2 expression. Furthermore, treatment with recombinant human uPA (Rh-uPA) caused significant restoration of OS cell migration and invasion in MTA2 knockdown osteosarcoma cells. We found that ERK1/2 depletion increased the expression of uPA, facilitating osteosarcoma cell migration and invasion. Finally, MTA2 depletion significantly reduced tumor metastasis and the formation of lung nodules in vivo. Overall, our study suggests that MTA2 knockdown suppresses osteosarcoma cell metastasis by decreasing uPA expression via ERK signaling. This finding provides new insight into potential treatment strategies against osteosarcoma metastasis by targeting MTA2.

Association of Trophectoderm mRNAs and MicroRNAs with Chromosomal Aneuploidy of Embryo

MicroRNAs (miRNAs) and mRNAs can serve as indicators of the chromosomal state of an embryo, with different profiles observed in euploid and aneuploid blastocysts. Examining the levels of miRNAs associated with aneuploidy and euploidy, as well as mRNAs related to implantation, can aid in predicting blastocyst chromosomal normality and improving assisted reproductive technology (ART) outcomes. This study analyzed chromosomal abnormality of 25 blastocysts using fluorescence in situ hybridization (FISH) and also the expression of genes ERBB4, SELL, ITGB3, and ITGAV, as well as miRNAs, miR-339, miR-27b, miR-661, miR-30c, miR-191, miR-345, miR-142, miR-141, miR-20a, and miR-372. We found that 17 out of 25 embryos were aneuploid. Moreover, results revealed lower expression levels of miR-30c and miR-372 in aneuploid embryos compared to euploid ones, while ITGAV and ITGB3 showed significantly higher expression in aneuploid embryos. These findings suggest that miR-372, miR-30c, ITGAV, and ITGB3 expression in trophectoderm cells can serve as biomarkers for assessing embryo health.

Photoinduced Cuproptosis with Tumor-Specific for Metastasis-Inhibited Cancer Therapy

Cuproptosis is a novel form of regulated cell death which guarantees to increase the efficacy of existing anticancer treatments that employ traditional apoptotic therapeutics. However, reducing the amount of undesirable Cu ions released in normal tissue and maximizing Cu-induced cuproptosis therapeutic effects at tumor sites are the major challenges. In this study, exploiting the chemical properties of copper ionophores and the tumor microenvironment, a novel method is developed for controlling the valence of copper ions that cause photoinduced cuproptosis in tumor cells. CJS-Cu nanoparticles (NPs) can selectively induce cuproptosis after cascade reactions through H2 O2 -triggered Cu2+ release, photoirradiation-induced superoxide radical (∙O2 - ) generation, and reduction of Cu2+ to Cu+ by ∙O2 - . The generated reactive oxygen species can result in glutathione depletion and iron-sulfur cluster protein damage and further augmented cuproptosis. CJS-Cu NPs effectively suppressed tumor growth and downregulated the expression of metastasis-related proteins, contributing to the complete inhibition of lung metastasis. Ultimately, this study suggests novel avenues for the manipulation of cellular cuproptosis through photochemical reactions.

CircMTA2 Drives Gastric Cancer Progression through Suppressing MTA2 Degradation via Interacting with UCHL3

Our previous study has reported that metastasis-associated protein 2 (MTA2) plays essential roles in tumorigenesis and aggressiveness of gastric cancer (GC). However, the underlying molecular mechanisms of MTA2-mediated GC and its upstream regulation mechanism remain elusive. In this study, we identified a novel circular RNA (circRNA) generated from the MTA2 gene (circMTA2) as a crucial regulator in GC progression. CircMTA2 was highly expressed in GC tissues and cell lines, and circMTA2 promoted the proliferation, invasion, and metastasis of GC cells both in vitro and in vivo. Mechanistically, circMTA2 interacted with ubiquitin carboxyl-terminal hydrolase L3 (UCHL3) to restrain MTA2 ubiquitination and stabilize MTA2 protein expression, thereby facilitating tumor progression. Moreover, circMTA2 was mainly encapsulated and transported by exosomes to promote GC cell progression. Taken together, these findings uncover that circMTA2 suppresses MTA2 degradation by interacting with UCHL3, thereby promoting GC progression. In conclusion, we identified a cancer-promoting axis (circMTA2/UCHL3/MTA2) in GC progression, which paves the way for us to design and synthesize targeted inhibitors as well as combination therapies.

An Activatable Prodrug Nanosystem for Ultrasound-Driven Multimodal Tumor Therapy and Metastasis Inhibition

Ultrasound, featuring deep tissue penetration and noninvasiveness, offers a new opportunity to activate functional materials in a tumor-selective manner. However, very few direct ultrasound-responsive redox systems are applicable under therapeutic ultrasound (1 MHz). Herein, the investigations on nanoprodrug of DHE@PEG-SS-DSPE are reported, which exhibit glutathione-activated release of dihydroethidium (DHE) in tumor cells. DHE is stable with good biosafety and is transformed into cytotoxic ethidium to induce DNA damage under medical ultrasound irradiation, accompanied by the generation of reactive oxygen species. Further, DHE@PEG-SS-DSPE could effectively induce ferroptosis through glutathione depletion, lipid peroxide accumulation, and downregulation of glutathione peroxidase 4. In vivo studies confirmed that DHE@PEG-SS-DSPE nanoparticles effectively inhibit both the growth of solid tumors and the expression of metastasis-related proteins in mice, thus effectively inhibiting lung metastasis. This DHE-based prodrug nanosystem could lay a foundation for the design of ultrasound-driven therapeutic agents.

Prognostic, Immunological, and Mutational Analysis of MTA2 in Pan-Cancer and Drug Screening for Hepatocellular Carcinoma

BACKGROUND

Metastasis-associated protein 2 (MTA2) is a member of the metastasis-associated transcriptional regulator family and is a core component of the nucleosome remodeling and histone deacetylation complex. Despite growing evidence that MTA2 plays a crucial role in the tumorigenesis of certain cancers, no systematic pan-cancer analysis of MTA2 is available to date. Therefore, the aim of our study is to explore the prognostic value of MTA2 in 33 cancer types and to investigate its potential immune function.

METHODS

by comprehensive use of databases from TCGA, GTEx, GEO, UCSC xena, cBioPortal, comPPI, GeneMANIA, TCIA, MSigDB, and PDB, we applied various bioinformatics approaches to investigate the potential role of MTA2, including analyzing the association of MTA2 with MSI, prognosis, gene mutation, and immune cell infiltration in different tumors. We constructed a nomogram in TCGA-LIHC, performed single-cell sequencing (scRNA-seq) analysis of MTA2 in hepatocellular carcinoma (HCC), and screened drugs for the treatment of HCC. Finally, immunohistochemical experiments were performed to verify the expression and prognostic value of MTA2 in HCC. In vitro experiments were employed to observe the growth inhibition effects of MK-886 on the HCC cell line HepG2.

RESULTS

The results suggested that MTA2 was highly expressed in most cancers, and MTA2 expression was associated with the prognosis of different cancers. In addition, MTA2 expression was associated with Tumor Mutation Burden (TMB) in 12 cancer types and MSI in 8 cancer types. Immunoassays indicated that MTA2 positively correlated with activated memory CD4 T cells and M0 macrophage infiltration levels in HCC. ScRNA-seq analysis based on the GEO dataset discovered that MTA2 was significantly expressed in T cells in HCC. Finally, the eXtreme Sum (Xsum) algorithm was used to screen the antitumor drug MK-886, and the molecular docking technique was utilized to reveal the binding capacity between MK-886 and the MTA2 protein. The results demonstrated excellent binding sites between them, which bind to each other through Π-alkyl and alkyl interaction forces. An immunohistochemistry experiment showed that MTA2 protein was highly expressed in HCC, and high MTA2 expression was associated with poor survival in HCC patients. MK-886 significantly inhibited the proliferation and induced cell death of HepG2 cells in a dose-dependent manner.

CONCLUSIONS

Our study demonstrated that MTA2 plays crucial roles in tumor progression and tumor immunity, and it could be used as a prognostic marker for various malignancies. MK-886 might be a powerful drug for HCC.

Emerging role for R-loop formation in hepatocellular carcinoma

The pathophysiological characteristics of hepatocellular carcinoma (HCC) is closely associated with genomic instability. Genomic instability has long been considered to be a hallmark of both human genetic disease and cancers. It is now well accepted that regulating R-loop formation to minimized levels is one of critical modulation to maintain genome integrity, and that improper regulation of R-loop metabolism causes genomic instability via DNA breakage, ultimately resulting in replicative senescence and even tumorigenesis. Given that R-loop is natural by-product formed during normal transcription condition, and that several types of cancer have defense mechanism against the genomic instability resulted from R-loop formation, modulating functional implication of proteins involved in the intrinsic and specific mechanisms of abnormal R-loop formation in cancers therefore could play an important part in appropriated therapeutic strategies for HCC cohorts. In this review, we highlight the latest understanding on how R-loops promote genomic instability and address how alterations in these pathways link to human HCC.

MTA2 is one of 14 Transcription factors predicting recurrence free survival in gastric cancer and promotes cancer progression by targeting MCM5

Gastric cancer (GC) is a leading cause of cancer-related death worldwide. Transcription factors (TFs) are essential gene expression regulators, and play critical roles in cancer development. However, the biological actions and prognostic value of TFs in GC remain unclear. In this study, we identified a risk model based on a 14-TF signature to predict recurrence-free survival in patients with GC. We further analyzed the ability of 14-TF to predict recurrence-free survival time in GC and found that a higher expression level of metastasis-associated protein 2 (MTA2) was associated with shorter overall survival and disease-free survival time in GC. Through in vitro and in vivo experiments, we demonstrated that MTA2 significantly promotes GC growth and metastasis. Furthermore, we identified MTA2 binding to the promoter of minichromosome maintenance deficient 5 (MCM5), thereby promoting GC progression. Overall, these findings strongly support the prognostic potential of the 14-TFs signature and suggest that targeting MTA2 may be a promising strategy to treat GC.

Serum proteomic profiling reveals MTA2 and AGO2 as potential prognostic biomarkers associated with disease activity and adverse outcomes in multiple myeloma

Multiple myeloma (MM) is an incurable plasma cell malignancy accounting for approximately 10% of hematological malignancies. Identification of reliable biomarkers for better diagnosis and prognosis remains a major challenge. This study aimed to identify potential serum prognostic biomarkers corresponding to MM disease activity and evaluate their impact on patient outcomes. Serum proteomic profiles of patients with MM and age-matched controls were performed using LC-MS/MS. In the verification and validation phases, the concentration of the candidate biomarkers was measured using an ELISA technique. In addition, the association of the proposed biomarkers with clinical outcomes was assessed. We identified 23 upregulated and 15 downregulated proteins differentially expressed in newly diagnosed and relapsed/refractory MM patients compared with MM patients who achieved at least a very good partial response to treatment (≥VGPR). The top two candidate proteins, metastasis-associated protein-2 (MTA2) and argonaute-2 (AGO2), were selected for further verification and validation studies. Both MTA2 and AGO2 showed significantly higher levels in the disease-active states than in the remission states (p < 0.001). Regardless of the patient treatment profile, high MTA2 levels were associated with shorter progression-free survival (p = 0.044; HR = 2.48; 95% CI, 1.02 to 6.02). Conversely, high AGO2 levels were associated with IgG and kappa light-chains isotypes and an occurrence of bone involvement features (p < 0.05) and were associated with prolonged time to response (p = 0.045; HR = 3.00; 95% CI, 1.03 to 8.76). Moreover, the analytic results using a publicly available NCBI GEO dataset revealed that AGO2 overexpression was associated with shorter overall survival among patients with MM (p = 0.032, HR = 1.60, 95% CI, 1.04 to 2.46). In conclusion, MTA2 and AGO2 proteins were first identified as potential biomarkers that reflect disease activity, provide prognostic values and could serve as non-invasive indicators for disease monitoring and outcome predicting among patients with MM.

Identification of potential inhibitory analogs of metastasis tumor antigens (MTAs) using bioactive compounds: revealing therapeutic option to prevent malignancy

The deeper understanding of metastasis phenomenon and detection of drug targets could be a potential approach to minimize cancer mortality. In this study, attempts were taken to unmask novel therapeutics to prevent metastasis and cancer progression. Initially, we explored the physiochemical, structural and functional insights of three metastasis tumor antigens (MTAs) and evaluated some plant-based bioactive compounds as potent MTA inhibitors. From 50 plant metabolites screened, isoflavone, gingerol, citronellal and asiatic acid showed maximum binding affinity with all three MTA proteins. The ADME analysis detected no undesirable toxicity that could reduce the drug likeness properties of top plant metabolites. Moreover, molecular dynamics studies revealed that the complexes were stable and showed minimum fluctuation at molecular level. We further performed ligand-based virtual screening to identify similar drug molecules using a large collection of 376,342 compounds from DrugBank. The results suggested that several structural analogs (e.g., tramadol, nabumetone, DGLA and hydrocortisone) may act as agonist to block the MTA proteins and inhibit cancer progression at early stage. The study could be useful to develop effective medications against cancer metastasis in future. Due to encouraging results, we highly recommend further in vitro and in vivo trials for the experimental validation of the findings.

Secreted Amyloid Precursor Protein Alpha, a Neuroprotective Protein in the Brain Has Widespread Effects on the Transcriptome and Proteome of Human Inducible Pluripotent Stem Cell-Derived Glutamatergic Neurons Related to Memory Mechanisms

Secreted amyloid precursor protein alpha (sAPPα) processed from a parent human brain protein, APP, can modulate learning and memory. It has potential for development as a therapy preventing, delaying, or even reversing Alzheimer’s disease. In this study a comprehensive analysis to understand how it affects the transcriptome and proteome of the human neuron was undertaken. Human inducible pluripotent stem cell (iPSC)-derived glutamatergic neurons in culture were exposed to 1 nM sAPPα over a time course and changes in the transcriptome and proteome were identified with RNA sequencing and Sequential Window Acquisition of All THeoretical Fragment Ion Spectra-Mass Spectrometry (SWATH-MS), respectively. A large subset (∼30%) of differentially expressed transcripts and proteins were functionally involved with the molecular biology of learning and memory, consistent with reported links of sAPPα to memory enhancement, as well as neurogenic, neurotrophic, and neuroprotective phenotypes in previous studies. Differentially regulated proteins included those encoded in previously identified Alzheimer’s risk genes, APP processing related proteins, proteins involved in synaptogenesis, neurotransmitters, receptors, synaptic vesicle proteins, cytoskeletal proteins, proteins involved in protein and organelle trafficking, and proteins important for cell signalling, transcriptional splicing, and functions of the proteasome and lysosome. We have identified a complex set of genes affected by sAPPα, which may aid further investigation into the mechanism of how this neuroprotective protein affects memory formation and how it might be used as an Alzheimer’s disease therapy.

Identification and validation of a novel prognostic signature based on transcription factors in breast cancer by bioinformatics analysis

BACKGROUND

Breast cancer (BRCA) is the leading cause of cancer mortality among women, and it is associated with many tumor suppressors and oncogenes. There is increasing evidence that transcription factors (TFs) play vital roles in human malignancies, but TFs-based biomarkers for BRCA prognosis were still rare and necessary. This study sought to develop and validate a prognostic model based on TFs for BRCA patients.

METHODS

Differentially expressed TFs were screened from 1,109 BRCA and 113 non-tumor samples downloaded from The Cancer Genome Atlas (TCGA). Univariate Cox regression analysis was used to identify TFs associated with overall survival (OS) of BRCA, and multivariate Cox regression analysis was performed to establish the optimal risk model. The predictive value of the TF model was established using TCGA database and validated using a Gene Expression Omnibus (GEO) data set (GSE20685). A gene set enrichment analysis was conducted to identify the enriched signaling pathways in high-risk and low-risk BRCA patients. Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the TF target genes were also conducted separately.

RESULTS

A total of 394 differentially expressed TFs were screened. A 9-TF prognostic model, comprising PAX7, POU3F2, ZIC2, WT1, ALX4, FOXJ1, SPIB, LEF1 and NFE2, was constructed and validated. Compared to those in the low-risk group, patients in the high-risk group had worse clinical outcomes (P<0.001). The areas under the curve of the prognostic model for 5-year OS were 0.722 in the training cohort and 0.651 in the testing cohort. Additionally, the risk score was an independent prediction indicator for BRCA patients both in the training cohort (HR =1.757, P<0.001) and testing cohort (HR =1.401, P=0.001). It was associated with various cancer signaling pathways. Ultimately, 9 overlapping target genes were predicted by 3 prediction nomograms. The GO and KEGG enrichment analyses of these target genes suggested that the TFs in the model may regulate the activation of some classical tumor signaling pathways to control the progression of BRCA through these target genes.

CONCLUSIONS

Our study developed and validated a novel prognostic TF model that can effectively predict 5-year OS for BRCA patients.

SNHG5 inhibits the progression of EMT through the ubiquitin-degradation of MTA2 in oesophageal cancer

A substantial fraction of transcripts are known as long noncoding RNAs (lncRNAs), and these transcripts play pivotal roles in the development of cancer. However, little information has been published regarding the functions of lncRNAs in oesophageal squamous cell carcinoma (ESCC) and the underlying mechanisms. In our previous studies, we demonstrated that small nucleolar RNA host gene 5 (SNHG5), a known lncRNA, is dysregulated in gastric cancer (GC). In this study, we explored the expression and function of SNHG5 in development of ESCC. SNHG5 was found to be downregulated in human ESCC tissues and cell lines, and this downregulation was associated with cancer progression, clinical outcomes and survival rates of ESCC patients. Furthermore, we also found that overexpression of SNHG5 significantly inhibited the proliferation, migration and invasion of ESCC cells in vivo and in vitro. Notably, we found that metastasis-associated protein 2 (MTA2) was pulled down by SNHG5 in ESCC cells using RNA pulldown assay. We also found that SNHG5 reversed the epithelial-mesenchymal transition by interacting with MTA2. In addition, overexpression of SNHG5 downregulated the transcription of MTA2 and caused its ubiquitin-mediated degradation. Thus, overexpression of MTA2 partially abrogated the effect of SNHG5 in ESCC cell lines. Furthermore, we found that MTA2 mRNA expression was significantly elevated in ESCC specimens, and a negative correlation between SNHG5 and MTA2 expression was detected. Overall, this study demonstrated, for the first time, that SNHG5-regulated MTA2 functions as an important player in the progression of ESCC and provide a new potential therapeutic strategy for ESCC.

MTA2 silencing attenuates the metastatic potential of cervical cancer cells by inhibiting AP1-mediated MMP12 expression via the ASK1/MEK3/p38/YB1 axis

Metastasis-associated protein 2 (MTA2) is a transcription factor that is highly associated with matrix metalloproteinase 12 (MMP12). Thus, we hypothesized that MTA2 may regulate MMP12 expression and is involved in cervical cancer metastasis. Results showed that MTA2 and MMP12 were highly expressed in cervical cancer cells, and MTA2 knockdown reduced MMP12 expression and inhibited the metastasis of cervical cancer cells in xenograft mice. MMP12 knockdown did not influence the viability of cervical cancer cells but clearly inhibited cell migration and invasion both in vitro and in vivo. MMP12 was highly expressed in cervical tumor tissues and correlated with the poor survival rate of patients with cervical cancer. Further investigations revealed that p38 mitogen-activated protein kinase (p38), mitogen-activated protein kinase kinase 3 (MEK3), and apoptosis signal-regulating kinase 1 (ASK1) were involved in MMP12 downregulation in response to MTA2 knockdown. Results also demonstrated that p38-mediated Y-box binding protein1 (YB1) phosphorylation disrupted the binding of AP1 (c-Fos/c-Jun) to the MMP12 promoter, thereby inhibiting MMP12 expression and the metastatic potential of cervical cancer cells. Collectively, targeting both MTA2 and MMP12 may be a promising strategy for the treatment of cervical cancer.

MTA2 promotes the metastasis of esophageal squamous cell carcinoma via EIF4E-Twist feedback loop

Metastasis‐associated protein 2 (MTA2) is frequently amplified in many types of cancers; however, the role and underlying molecular mechanism of MTA2 in esophageal squamous cell carcinoma (ESCC) remain unknown. Here, we reported that MTA2 is highly expressed in ESCC tissue and cells, and is closely related to the malignant characteristics and poor prognosis of patients with ESCC. Through in vitro and in vivo experiments, we demonstrated that MTA2 significantly promoted ESCC growth, metastasis, and epithelial‐mesenchymal transition (EMT) progression. This integrative analysis combined with expression microarray showed that MTA2 could interact with eukaryotic initiation factor 4E (EIF4E), which positively regulates the expression of Twist, known as a master regulator of EMT. Moreover, the results of chromatin immunoprecipitation revealed that MTA2 was recruited to the E‐cadherin promoter by Twist, which reduced the acetylation level of the promoter region and thus inhibited expression of E‐cadherin, and subsequently promoted the aggressive progression of ESCC. Collectively, our study provided novel evidence that MTA2 plays an aggressive role in ESCC metastasis by a novel EIF4E‐Twist positive feedback loop, which may provide a potential therapeutic target for the management of ESCC.

Identification of potential inhibitory analogs of metastasis tumor antigens (MTAs) using bioactive compounds: revealing therapeutic option to prevent malignancy.. [DOI: 10.1101/2020.10.19.345975]

The deeper understanding of metastasis phenomenon and detection of drug targets could be a potential approach to minimize cancer mortality. In this study, attempts were taken to unmask novel therapeutics to prevent metastasis and cancer progression. Initially, we explored the physiochemical, structural and functional insights of three metastasis tumor antigens (MTAs) and evaluated some plant based bioactive compounds as potent MTA inhibitors. From 50 plant metabolites screened, isoflavone, gingerol, citronellal and asiatic acid showed maximum binding affinity with all three MTA proteins. The ADME analysis detected no undesirable toxicity that could reduce the drug likeness properties of top plant metabolites. Moreover, molecular dynamics studies revealed that the complexes were stable and showed minimum fluctuation at molecular level. We further performed ligand based virtual screening to identify similar drug molecules using a large collection of 3,76,342 compounds from DrugBank. The results suggested that several structural analogs (e.g. Tramadol, Nabumetone, DGLA, Hydrocortisone) may act as agonist to block the MTA proteins and inhibit cancer progression at early stage. The study could be useful to develop effective medications against cancer metastasis in future. Due to encouraging results, we highly recommend furtherin vitroandin vivotrials for the experimental validation of the findings.

An isoflavone derivative potently inhibits the angiogenesis and progression of triple-negative breast cancer by targeting the MTA2/SerRS/VEGFA pathway

Objective: Angiogenesis plays a vital role in tumor growth and metastasis. Here, we aimed to find novel efficient antiangiogenic molecules targeting vascular endothelial growth factor A (VEGFA ) at the transcriptional level to treat triple-negative breast cancer (TNBC). Methods: We used a cell-based seryl tRNA synthetase (SerRS) promoter-driven dual-luciferase reporter system to screen an in-house library of 384 naturally occurring small molecules and their derivatives to find candidate molecules that could upregulate the expression of SerRS, a potent transcriptional repressor of VEGFA. The levels of SerRS and VEGFA were examined by quantitative RT-PCR (qRT-PCR), western blotting, and/or ELISAs in TNBC cells after candidate molecule administration. Zebrafish, the Matrigel plug angiogenesis assay in mice, the TNBC allograft, and xenograft mouse models were used to evaluate the in vivo anti-angiogenic and anti-cancer activities. Furthermore, the potential direct targets of the candidates were identified by proteomics and biochemical studies. Results: We found the most active compound was 3-(4-methoxyphenyl) quinolin-4(1H)-one (MEQ), an isoflavone derivative. In TNBC cells, MEQ treatment resulted in increased SerRS mRNA (P < 0.001) and protein levels and downregulated VEGFA production. Both the vascular development of zebrafish and Matrigel plug angiogenesis in mice were inhibited by MEQ. MEQ also suppressed the angiogenesis in TNBC allografts and xenografts in mice, resulting in inhibited tumor growth and prolonged overall survival (P < 0.05). Finally, we found that MEQ regulated SerRS transcription by interacting with MTA2 (Metastasis Associated 1 Family Member 2). Conclusions: Our findings suggested that the MTA2/SerRS/VEGFA axis is a drug-treatable anti-angiogenic target, and MEQ is a promising anti-tumor molecule that merits further investigation for clinical applications.

Transcriptional Suppression of miR-7 by MTA2 Induces Sp1-Mediated KLK10 Expression and Metastasis of Cervical Cancer

MTA2 is involved in tumor proliferation and metastasis. However, the role of MTA2 in cervical cancer thus far has not been identified. In this study, we report that elevated expression of MTA2 negatively correlates with Kallikrein-10 (KLK10) expression and poor prognosis of cervical cancer patients. Knockdown of MTA2 substantially inhibited tumor cell migration and invasion, and it enhanced KLK10 expression of the cervical cancer cells in vitro and in vivo. Functionally, shMTA2-mediated suppression of cell mobility was significantly restored by knockdown of KLK10. We also found that Sp1 (transcription factor specificity protein 1) is critical for shMTA2-induced transcriptional upregulation of KLK10 and subsequent biological functions. Furthermore, we found that the expression of miR-7 is elevated by MTA2 silencing and then by direct inhibition of Sp1 expression. Knockdown of Sp1 additively enhanced KLK10 expression in MTA2-knocked down cervical cancer cells, suggesting that the miR-7/Sp1 axis acts as an effector of MTA2 to impact KLK10 levels and mobility of cervical cancer cells. Taken together, our findings provide new insights into the physiological relationship between MTA2 and KLK10 via regulating the miR-7/Sp1 axis, and they provide a potential therapeutic target in cervical cancer.

Transformable hybrid semiconducting polymer nanozyme for second near-infrared photothermal ferrotherapy

Despite its growing promise in cancer treatment, ferrotherapy has low therapeutic efficacy due to compromised Fenton catalytic efficiency in tumor milieu. We herein report a hybrid semiconducting nanozyme (HSN) with high photothermal conversion efficiency for photoacoustic (PA) imaging-guided second near-infrared photothermal ferrotherapy. HSN comprises an amphiphilic semiconducting polymer as photothermal converter, PA emitter and iron-chelating Fenton catalyst. Upon photoirradiation, HSN generates heat not only to induce cytotoxicity but also to enhance Fenton reaction. The increased ·OH generation promotes both ferroptosis and apoptosis, oxidizes HSN (42 nm) and transforms it into tiny segments (1.7 nm) with elevated intratumoral permeability. The non-invasive seamless synergism leads to amplified therapeutic effects including a deep ablation depth (9 mm), reduced expression of metastasis-related proteins and inhibition of metastasis from primary tumor to distant organs. Thereby, our study provides a generalized nanozyme strategy to compensate both ferrotherapy and phototherapeutics for complete tumor regression.

Due to tumour microenvironment, Fenton reactions have low therapeutic efficiency. Here the authors report on the application of NIR-II hybrid semiconducting nanozymes for combined photothermal therapy and enhanced ferrotherapy with photoacoustic imaging and show application in vivo in tumour models.

LncRNA HOTAIR promotes the invasion and metastasis of oral squamous cell carcinoma through metastasis-associated gene 2

Despite therapeutic advancements, there has been little improvement in the survival status of patients with oral squamous cell carcinoma (OSCC). HOX antisense intergenic RNA (HOTAIR) has been shown to be dysregulated in several cancer types. However, the roles of HOTAIR in OSCC remain largely unknown. In this study, we investigated the association of HOTAIR expression with clinicopathological features in OSCC patients and the crucial roles of HOTAIR in the modulation of tumor progression. Our results showed that HOTAIR was highly expressed both in OSCC tissue samples and cell lines compared with corresponding normal oral mucosa tissues and human oral keratinocytes. Its overexpression was positively correlated with TNM (tumor-node-metastases) stage, histological grade, and regional lymph node metastasis. The knockdown of HOTAIR by short hairpin RNA significantly decreased the migration, invasion, and epithelial-mesenchymal transition of OSCC cells in vitro. Moreover, there was a negative correlation between HOTAIR and microRNA-326 expression in OSCC tissue samples and cell lines. Luciferase reporter and loss-of-function assays revealed that HOTAIR acted as a competitive endogenous RNA effectively sponging miR-326, thereby regulating the derepression of metastasis-associated gene 2 (MTA2). Finally, the expression and clinical significance of MTA2 were analyzed in another cohort of OSCC tissue samples. High MTA2 expression was significantly correlated with clinicopathological features of advanced OSCC and poor prognosis for patients with OSCC. Collectively, HOTAIR overexpression promoted the progression of OSCC. The HOTAIR-miR-326-MTA2 axis may contribute to a better understanding of OSCC pathogenesis and be a potential therapeutic target for OSCC.

Extensive rewiring of the EGFR network in colorectal cancer cells expressing transforming levels of KRASG13D

Protein-protein-interaction networks (PPINs) organize fundamental biological processes, but how oncogenic mutations impact these interactions and their functions at a network-level scale is poorly understood. Here, we analyze how a common oncogenic KRAS mutation (KRASG13D) affects PPIN structure and function of the Epidermal Growth Factor Receptor (EGFR) network in colorectal cancer (CRC) cells. Mapping >6000 PPIs shows that this network is extensively rewired in cells expressing transforming levels of KRASG13D (mtKRAS). The factors driving PPIN rewiring are multifactorial including changes in protein expression and phosphorylation. Mathematical modelling also suggests that the binding dynamics of low and high affinity KRAS interactors contribute to rewiring. PPIN rewiring substantially alters the composition of protein complexes, signal flow, transcriptional regulation, and cellular phenotype. These changes are validated by targeted and global experimental analysis. Importantly, genetic alterations in the most extensively rewired PPIN nodes occur frequently in CRC and are prognostic of poor patient outcomes.

MTA2 as a Potential Biomarker and Its Involvement in Metastatic Progression of Human Renal Cancer by miR-133b Targeting MMP-9

Metastasis-associated protein 2 (MTA2) was previously known as a requirement to maintain malignant potentials in several human cancers. However, the role of MTA2 in the progression of renal cell carcinoma (RCC) has not yet been delineated. In this study, MTA2 expression was significantly increased in RCC tissues and cell lines. Increased MTA2 expression was significantly associated with tumour grade (p = 0.002) and was an independent prognostic factor for overall survival with a high RCC tumour grade. MTA2 knockdown inhibited the migration, invasion, and in vivo metastasis of RCC cells without effects on cell proliferation. Regarding molecular mechanisms, MTA2 knockdown reduced the activity, protein level, and mRNA expression of matrix metalloproteinase-9 (MMP-9) in RCC cells. Further analyses demonstrated that patients with lower miR-133b expression had poorer survival rates than those with higher expression from The Cancer Genome Atlas database. Moreover, miR-133b modulated the 3′untranslated region (UTR) of MMP-9 promoter activities and subsequently the migratory and invasive abilities of these dysregulated expressions of MTA2 in RCC cells. The inhibition of MTA2 could contribute to human RCC metastasis by regulating the expression of miR-133b targeting MMP-9 expression.

Metastasis-associated protein 2 regulates human hepatocellular carcinoma metastasis progression through modulating p38MAPK/MMP2 pathways

Studies have shown the overexpression of metastasis-associated protein 2 (MTA2) to be associated with hepatocellular carcinoma (HCC) progression. However, the molecular mechanism of MTA2 expression in HCC is unclear. In our study, we found a higher level of MTA2 in HCC tissues than in normal tissues and a significant correlation between tumor grade and overall survival of HCC patients. We also found that MTA2 inhibition reduced the migration and invasion capabilities of HCC cells, independent of cell proliferation. Mechanistic studies have suggested that MTA2 protein and mRNA are more highly expressed in SK-Hep-1 and Huh-7 cells compared with other HCC cells. MTA2 silencing drastically reduced migration and invasion capability and also inhibited matrix metalloproteinase 2 (MMP2) at the transcriptional and translation levels in both cells. In addition, treatment with the MMP2 antibody markedly impaired MTA2-knockdown-mediated inhibition of migration and invasion in SK-Hep-1 cells. Furthermore, MTA2 knockdown reduced the phosphorylation of the p38MAPK protein, whereas the inhibition of p38MAPK (SB203580 or si-p38) confirmed that blocking the p38MAPK pathway mediated MTA2-knockdown-inhibited migration and invasion in SK-Hep-1 cells. We demonstrated the molecular mechanism by which MTA2 inhibits human HCC cell metastasis through the p38MAPK/MMP2 pathways, which might be helpful in determining the diagnostic value of this protein in patients with HCC

New prognostic markers revealed by RNA-Seq transcriptome analysis after MYC silencing in a metastatic gastric cancer cell line

MYC overexpression is considered a driver event in gastric cancer (GC), and is frequently correlated with poor prognosis and metastasis. In this study, we evaluated the prognostic value of genes upregulated by MYC in patients with GC. Metastatic GC cells (AGP01) characterized by MYC amplification, were transfected with siRNAs targeting MYC. RNA-seq was performed in silenced and non-silenced AGP01 cells. Among the differentially expressed genes, CIAPIN1, MTA2, and UXT were validated using qRT-PCR, western blot, and immunohistochemistry in gastric tissues of 213 patients with GC; and their expressions were correlated with clinicopathological and survival data. High mRNA and protein levels of CIAPIN1, MTA2, and UXT were strongly associated with advanced GC stages (P < 0.0001). However, only CIAPIN1 and UXT gene expressions were able to predict distant metastases in patients with early-stage GC (P < 0.0001), with high sensitivity (> 92%) and specificity (> 90%). Overall survival rate of patients with overexpressed CIAPIN1 or UXT was significantly lower (P < 0.0001). In conclusion, CIAPIN1 and UXT may serve as potential molecular markers for GC prognosis.

LncRNA-MTA2TR functions as a promoter in pancreatic cancer via driving deacetylation-dependent accumulation of HIF-1α

Rationale: Hypoxia has been proved to contribute to aggressive phenotype of cancers, while functional and regulatory mechanism of long noncoding RNA (lncRNA) in the contribution of hypoxia on pancreatic cancer (PC) tumorigenesis is incompletely understood. The aim of this study was to uncover the regulatory and functional roles for hypoxia-induced lncRNA-MTA2TR (MTA2 transcriptional regulator RNA, AF083120.1) in the regulation of PC tumorigenesis. Methods: A lncRNA microarray confirmed MTA2TR expression in tissues of PC patients. The effects of MTA2TR on proliferation and metastasis of PC cells and xenograft models were determined, and the key mechanisms by which MTA2TR promotes PC were further dissected. Furthermore, the expression and regulation of MTA2TR under hypoxic conditions in PC cells were assessed. We also assessed the correlation between MTA2TR expression and PC patient clinical outcomes. Results: We found that metastasis associated protein 2 (MTA2) transcriptional regulator lncRNA (MTA2TR) was overexpressed in PC patient tissues relative to paired noncancerous tissues. Furthermore, we found that depletion of MTA2TR significantly inhibited PC cell proliferation and invasion both in vitro and in vivo. We further demonstrated that MTA2TR transcriptionally upregulates MTA2 expression by recruiting activating transcription factor 3 (ATF3) to the promoter area of MTA2. Consequentially, MTA2 can stabilize the HIF-1α protein via deacetylation, which further activates HIF-1α transcriptional activity. Interestingly, our results revealed that MTA2TR is transcriptionally regulated by HIF-1α under hypoxic conditions. Our clinical samples further indicated that the overexpression of MTA2TR was correlated with MTA2 upregulation, as well as with reduced overall survival (OS) in PC patients. Conclusions: These results suggest that feedback between MTA2TR and HIF-1α may play a key role in regulating PC tumorigenesis, thus potentially highlighting novel avenues PC treatment.

MicroRNA-589 serves as a tumor suppressor microRNA through directly targeting metastasis-associated protein 2 in breast cancer

Triple-negative breast cancer (TNBC) has a poorer outcome compared with that of other subtypes of breast cancer, and the discovery of dysregulated microRNA (miRNA) and their role in tumor progression has provided a new avenue for elucidating the mechanism involved in TNBC. Previous studies have revealed that aberrant expression of miRNA-589 (miR-589) was frequently observed in various types of cancer. However, the expression and function of miR-589 in TNBC has not been well illustrated. In the present study, the expression level of miR-589 was explored in TNBC tissues and TNBC cell lines by quantitative polymerase chain reaction (qPCR). The results revealed that the expression of miR-589 was decreased in TNBC tissues and cell lines compared with that in normal tissues and breast cell lines. Furthermore, miR-589 overexpression decreased the TNBC cell proliferation, migration and invasion, whereas miR-589 silencing generated the opposite results in vitro. Bioinformatic algorithms predicted a direct target site for miR-589 in the 3′-untranslated region of metastasis-associated protein 2 (MTA2), which was confirmed with a dual-luciferase reporter assay and western blot analysis. Results of the qPCR and western blot analysis illustrated that miR-589 negatively regulated MTA2 expression with regard to mRNA and protein levels in the TNBC cell lines. MTA2 silencing reversed the promotion function of miR-589 inhibitor in the TNBC cell line. Finally, miR-589 could inhibit the process of epithelial-mesenchymal transition via MTA2. In summary, the present study revealed the biological function and molecular mechanism of miR-589 in the progression of TNBC. MiR-589 inhibition in the progression of TNBC may be a potential therapeutic target for TNBC.

Targeting Super-Enhancer-Driven Oncogenic Transcription by CDK7 Inhibition in Anaplastic Thyroid Carcinoma

Background: Anaplastic thyroid carcinoma (ATC) is one of the most aggressive malignancies, with no effective treatment currently available. The molecular mechanisms of ATC carcinogenesis remain poorly understood. The objective of this study was to investigate the mechanisms and functions of super-enhancer (SE)-driven oncogenic transcriptional addiction in the progression of ATC and identify new drug targets for ATC treatments. Methods: High-throughput chemical screening was performed to identify new drugs inhibiting ATC cell growth. Cell viability assay, colony formation analysis, cell-cycle analysis, and animal study were used to examine the effects of drug treatments on ATC progression. Chromatin immunoprecipitation sequencing was conducted to establish a SE landscape of ATC. Integrative analysis of RNA sequencing, chromatin immunoprecipitation sequencing, and CRISPR/Cas9-mediated gene editing was used to identify THZ1 target genes. Drug combination analysis was performed to assess drug synergy. Patient samples were analyzed to evaluate candidate biomarkers of prognosis in ATC. Results: THZ1, a covalent inhibitor of cyclin-dependent kinase 7 (CDK7), was identified as a potent anti-ATC compound by high-throughput chemical screening. ATC cells, but not papillary thyroid carcinoma cells, are exceptionally sensitive to CDK7 inhibition. An integrative analysis of both gene expression profiles and SE features revealed that the SE-mediated oncogenic transcriptional amplification mediates the vulnerability of ATC cells to THZ1 treatment. Combining this integrative analysis with functional assays led to the discovery of a number of novel cancer genes of ATC, including PPP1R15A, SMG9, and KLF2. Inhibition of PPP1R15A with Guanabenz or Sephin1 greatly suppresses ATC growth. Significantly, the expression level of PPP1R15A is correlated with CDK7 expression in ATC tissue samples. Elevated expression of PPP1R15A and CDK7 are both associated with poor clinical prognosis in ATC patients. Importantly, CDK7 or PPP1R15A inhibition sensitizes ATC cells to conventional chemotherapy. Conclusions: Taken together, these findings demonstrate transcriptional addiction in ATC pathobiology and identify CDK7 and PPP1R15A as potential biomarkers and therapeutic targets for ATC.

The Nucleosome Remodelling and Deacetylation complex suppresses transcriptional noise during lineage commitment

Multiprotein chromatin remodelling complexes show remarkable conservation of function amongst metazoans, even though components present in invertebrates are often found as multiple paralogous proteins in vertebrate complexes. In some cases, these paralogues specify distinct biochemical and/or functional activities in vertebrate cells. Here, we set out to define the biochemical and functional diversity encoded by one such group of proteins within the mammalian Nucleosome Remodelling and Deacetylation (NuRD) complex: Mta1, Mta2 and Mta3. We find that, in contrast to what has been described in somatic cells, MTA proteins are not mutually exclusive within embryonic stem (ES) cell NuRD and, despite subtle differences in chromatin binding and biochemical interactions, serve largely redundant functions. ES cells lacking all three MTA proteins exhibit complete NuRD loss of function and are viable, allowing us to identify a previously unreported function for NuRD in reducing transcriptional noise, which is essential for maintaining a proper differentiation trajectory during early stages of lineage commitment.

MTA2-mediated inhibition of PTEN leads to pancreatic ductal adenocarcinoma carcinogenicity

Metastasis-associated protein 2 (MTA2) is a core subunit of the nucleosome remodeling and deacetylating (NuRD) complex and functions by mediating chromatin remodeling and gene silencing. However, its biological actions and clinical significance in pancreatic ductal adenocarcinoma (PDAC) remain elusive. The aim of this study was to explore the function and regulation mechanism of MTA2 in PDAC. As shown in GEO, ICGC, and TCGA databases, a higher expression of MTA2 was noticed in the PDAC tissues than in the normal pancreatic tissues. Moreover, a higher expression level of MTA2 was associated with a shorter overall survival time in these public PDAC databases. We further investigated the underlying mechanisms of these observations by using a chromatin immunoprecipitation (ChIP)-based deep sequencing, luciferase reporter, and quantitative ChIP assays. We identified the repressive binding of MTA2 to the promoter of phosphatase and tensin homolog (PTEN). We also found that Snail recruited MTA2 and HDAC1 to suppress PTEN expression. Ectopic expression and knockdown of MTA2 were performed to evaluate the effects of this gene on PDAC cell proliferation, migration, and invasion. Using CCK-8, colony formation and transwell assays, and a xenograft tumor model, we revealed that MTA2 promoted PDAC cell proliferation, migration, and invasion in vitro and PDAC tumor growth in vivo by downregulation of PTEN. In benzyl isothiocyanate (BITC)-treated MIA Paca-2 cells and PANC-1 cells, MTA2 level decreased in a dose- and time-dependent manner with concomitant upregulation of PTEN level and downregulation of phosphorylated PI3K and AKT levels, providing evidence of the involvement of MTA2 and PTEN in the regulation of the PI3K/AKT pathway in BITC-mediated PDAC suppression. Collectively, these findings uncover a novel role for MTA2 in the regulation of PDAC progression and help to elucidate the mechanisms involved in this process.

The effect of dielectrophoresis on living cells: crossover frequencies and deregulation in gene expression

This article documents the effect of dielectrophoresis on living cells.

Hepatotoxic Effects of Hexafluoropropylene Oxide Trimer Acid (HFPO-TA), A Novel Perfluorooctanoic Acid (PFOA) Alternative, on Mice

As an alternative to perfluorooctanoic acid (PFOA), hexafluoropropylene oxide trimer acid (HFPO-TA) has been increasingly used for fluoropolymer manufacture in recent years. Its growing detection in environmental matrices and wildlife raises considerable concern about its potential health risks. Here we investigated the effects of HFPO-TA on mouse liver following 28 days of exposure to 0.02, 0.1, or 0.5 mg/kg/d of HFPO-TA via oral gavage. Results showed that HFPO-TA concentrations increased to 1.14, 4.48, and 30.8 μg/mL in serum and 12.0, 32.2, and 100 μg/g in liver, respectively. Liver injury, including hepatomegaly, necrosis, and increase in alanine aminotransferase activity, was observed. Furthermore, total cholesterol and triglycerides decreased in the liver in a dose-dependent manner. Liver transcriptome analysis revealed that 281, 1001, and 2491 genes were differentially expressed (fold change ≥2 and FDR < 0.05) in the three treated groups, respectively, compared with the control group. KEGG enrichment analysis highlighted the PPAR and chemical carcinogenesis pathways in all three treatment groups. Protein levels of genes involved in carcinogenesis, such as AFP, p21, Sirt1 C-MYC, and PCNA, were significantly increased. Compared with previously published toxicological data of PFOA, HFPO-TA showed higher bioaccumulation potential and more serious hepatotoxicity. Taken together, HFPO-TA does not appear to be a safer alternative to PFOA.

Reciprocal loop of hypoxia-inducible factor-1α (HIF-1α) and metastasis-associated protein 2 (MTA2) contributes to the progression of pancreatic carcinoma by suppressing E-cadherin transcription

Metastasis-associated protein 2 (MTA2) is overexpressed in certain malignancies, and plays important roles in tumour metastasis and progression. The present study highlights the function of MTA2 in pancreatic carcinoma through its role as a deacetylator of hypoxia-inducible factor-1α (HIF-1α) and a cotranscriptional factor for E-cadherin expression. We found that overexpression of MTA2 promoted, and knockdown of MTA2 inhibited, the invasion and proliferation of pancreatic carcinoma cells both in vitro and in xenograft models in vivo. We also found that MTA2 is transcriptionally upregulated by HIF-1α through a hypoxia response element (HRE) of the MTA2 promoter in response to hypoxia. Reciprocally, MTA2 deacetylates HIF-1α and enhances its stability through interacting with histone deacetylase 1 (HDAC1). Consequently, HIF-1α recruits MTA2 and HDAC1 to the HRE of the E-cadherin promoter, by which E-cadherin transcription is repressed. In agreement with these experimental results, MTA2 is positively associated with HIF-1α, but inversely correlated with E-cadherin, in pancreatic carcinoma samples. Moreover, data from The Cancer Genome Atlas on 172 pancreatic carcinomas indicate an association between high expression of MTA2 and short overall survival. Taken together, our study identifies MTA2 as a critical hub and potential therapeutic target to inhibit the progression and metastasis of pancreatic carcinoma. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Metastasis-associated protein 3 in colorectal cancer determines tumor recurrence and prognosis

Metastasis-associated protein family (MTA) promotes tumor cell invasion and metastasis of human malignancies. However, the novel component of MTA family, MTA3 was found to play conflicting roles in human malignancies. While the expression pattern and potential function of MTA3 in colorectal cancer has not been addressed yet. In the present study, we investigated the protein expression of MTA3 by immunohistochemistry assay, analyzed its association with tumor progression, recurrence and prognosis in239 cases of patients. Results showed that MTA3 expression in colorectal cancer was significantly decreased in colorectal cancer compared with normal specimens. Its expression was found to be correlated with tumor differentiation, metastases and TNM stage. Kaplan–Meier analysis proved that MTA3 was associated with both disease-free survival and overall survival of patients with colorectal cancer that patients with negative MTA3 expression tend to have unfavorable outcome. Moreover, cox's proportional hazards analysis showed that negative MTA3 expression was an independent prognostic marker of poor outcome. These results provided the first evidence that MTA3 level was decreased in colorectal cancer and significantly correlated with tumor cell invasion and metastasis. It also demonstrated that MTA3 might serve as a potential marker of tumor recurrence and prognosis of colorectal cancer.

The macro-evolutionary events in esophageal squamous cell carcinoma

Understanding the evolutionary processes operative in cancer genome may provide insights into clinical outcome and drug-resistance. However, studies focus on genomic signatures, especially for macro-evolutionary events, in esophageal squamous cell carcinoma (ESCC) are limited. Here, we integrated published genomic sequencing data to investigate underlying evolutionary characteristics in ESCC. We found most of ESCC genomes were polyploidy with high genomic instability. Whole genome doubling that acts as one of mechanisms for polyploidy was predicted as a late event in the majority of ESCC genome. Moreover, loss of heterozygosity events were more likely to occur in chromosomes harboring tumor suppressor genes in ESCC. The 40% of neutral loss of heterozygosity events was not a result of genome doubling, suggesting an alternative mechanism for neutral loss of heterozygosity formation. Importantly, deconstruction of copy number alterations extending to telomere revealed that telomere-bounded copy number alterations play a critical role for amplification/deletion of oncogenes/suppressor genes. For well-known genes SOX2, PIK3CA and TERT, nearly all of their amplifications were telomere bounded, which was further confirmed in a Japanese ESCC cohort. Furthermore, we provide evidence that karyotype evolution was mostly punctuated in ESCC. Collectively, our data reveal the potential biological role of whole genome doubling, neutral loss of heterozygosity and telomere-bounded copy number alterations, and highlight mecro-evolution in ESCC tumorigenesis.

The nuclear receptor ERβ engages AGO2 in regulation of gene transcription, RNA splicing and RISC loading

BACKGROUND

The RNA-binding protein Argonaute 2 (AGO2) is a key effector of RNA-silencing pathways It exerts a pivotal role in microRNA maturation and activity and can modulate chromatin remodeling, transcriptional gene regulation and RNA splicing. Estrogen receptor beta (ERβ) is endowed with oncosuppressive activities, antagonizing hormone-induced carcinogenesis and inhibiting growth and oncogenic functions in luminal-like breast cancers (BCs), where its expression correlates with a better prognosis of the disease.

RESULTS

Applying interaction proteomics coupled to mass spectrometry to characterize nuclear factors cooperating with ERβ in gene regulation, we identify AGO2 as a novel partner of ERβ in human BC cells. ERβ-AGO2 association was confirmed in vitro and in vivo in both the nucleus and cytoplasm and is shown to be RNA-mediated. ChIP-Seq demonstrates AGO2 association with a large number of ERβ binding sites, and total and nascent RNA-Seq in ERβ + vs ERβ - cells, and before and after AGO2 knock-down in ERβ + cells, reveals a widespread involvement of this factor in ERβ-mediated regulation of gene transcription rate and RNA splicing. Moreover, isolation and sequencing by RIP-Seq of ERβ-associated long and small RNAs in the cytoplasm suggests involvement of the nuclear receptor in RISC loading, indicating that it may also be able to directly control mRNA translation efficiency and stability.

CONCLUSIONS

These results demonstrate that AGO2 can act as a pleiotropic functional partner of ERβ, indicating that both factors are endowed with multiple roles in the control of key cellular functions.

MicroRNA-148b suppresses proliferation, migration, and invasion of nasopharyngeal carcinoma cells by targeting metastasis-associated gene 2

PURPOSE

MicroRNAs (miRNAs) play important roles in tumorigenesis and metastasis by regulating genes expression. MiRNA-148b (miR-148b) had been reported to inhibit tumor progression in some kinds of cancers, but the functions of miR-148b in nasopharyngeal carcinoma (NPC) remain largely unknown. The aim of this study was to investigate the functional role of miR-148b in NPC.

METHODS

Expression of miR-148b in NPC tissues and cell lines was detected by quantitative reverse transcription polymerase chain reaction. MiR-148b was overexpressed in CNE2 and C666-1 cells by miR-148b mimic transfection. The effects of miR-148b on cell proliferation, migration, and invasion were determined by colony formation assays, cell viability assays, and transwell assays. The target gene of miR-148b was investigated by luciferase assays, and the rescue experiment was performed.

RESULTS

MiR-148b was downregulated in NPC tissues and cell lines. Ectopic miR-148b expression significantly inhibited proliferation, migration, and invasion of CNE2 and C666-1 cells. We identified that metastasis-associated gene 2 (MTA2) is a direct target of miR-148b. Rescue experiment demonstrated that the tumor-suppressive effects of miR-148b on C666-1 cell were partly reversed by restoration of MTA2 expression. Moreover, miR-148b expression was negatively related to mRNA level of MTA2 in NPC tissues.

CONCLUSION

Our findings elucidate that miR-148b negatively regulates the growth, migration, and invasion of NPC cells, at least in part, by targeting MTA2. The present study indicates that miR-148b is a potential therapeutic agent for NPC.

Gastric cancer pathogenesis

Gastric cancer (GC) results from a multistep process that is influenced by Helicobacter pylori infection, genetic susceptibility of the host, as well as of other environmental factors. GC results from the accumulation of numerous genetic and epigenetic alterations in oncogenes and tumor suppressor genes, leading to dysregulation of multiple signaling pathways, which disrupt the cell cycle and the balance between cell proliferation and cell death. For this special issue, we have selected to review last year's advances related to three main topics: the cell of origin that initiates malignant growth in GC, the mechanisms of direct genotoxicity induced by H. pylori infection, and the role of aberrantly expressed long noncoding RNAs in GC transformation. The understanding of the molecular basis of GC development is of utmost importance for the identification of novel targets for GC prevention and treatment.

Upregulation of metastasis-associated gene 2 promotes cell proliferation and invasion in nasopharyngeal carcinoma

Aims

Metastasis-associated gene 2 (MTA2) is reported to play an important role in tumor progression, but little is known about the role of MTA2 in nasopharyngeal carcinoma (NPC). The aim of the study was to explore the expression and function of MTA2 in NPC.

Methods

Expression of MTA2 in NPC tissues and cell lines was detected by immunohistochemistry and Western blotting. Relationship between MTA2 expression and clinicopathological features was analyzed. Stable MTA2-overexpressing and MTA2-siliencing NPC cells were established by transfection with plasmids encoding MTA2 cDNA and lentivirus-mediated short hairpin RNA, respectively. Cell viability was determined by Cell Counting Kit-8 and colony formation assay. Cell migration ability was evaluated by wound healing and transwell invasion assay. The impact of MTA2 knockdown on growth and metastasis of CNE2 cells in vivo was determined by nude mouse xenograft models. Expression of several Akt pathway proteins was detected by Western blotting.

Results

MTA2 was upregulated in NPC tissues and three NPC cell lines detected (CNE1, CNE2, and HNE1). MTA2 expression was related to clinical stage and lymph node metastasis of patients with NPC. MTA2 upregulation promoted proliferation and invasion of CNE1 cells, while MTA2 depletion had opposite effects on CNE2 cells. Moreover, MTA2 depletion suppressed growth and metastasis of CNE2 cells in vivo. MTA2 overexpression activated Akt and upregulated the expression of matrix metalloproteinase 7 and cyclin D1.

Conclusion

We conclude that MTA2 acts as an oncogene in tumorigenesis of NPC. MTA2 may be a potential target for gene therapy in NPC.

Human Blastocyst Secreted microRNA Regulate Endometrial Epithelial Cell Adhesion

Successful embryo implantation requires synchronous development and communication between the blastocyst and the endometrium, however the mechanisms of communication in humans are virtually unknown. Recent studies have revealed that microRNAs (miRs) are present in bodily fluids and secreted by cells in culture. We have identified that human blastocysts differentially secrete miRs in a pattern associated with their implantation outcome. miR-661 was the most highly expressed miR in blastocyst culture media (BCM) from blastocysts that failed to implant (non-implanted) compared to blastocysts that implanted (implanted). Our results indicate a possible role for Argonaute 1 in the transport of miR-661 in non-implanted BCM and taken up by primary human endometrial epithelial cells (HEECs). miR-661 uptake by HEEC reduced trophoblast cell line spheroid attachment to HEEC via PVRL1. Our results suggest that human blastocysts alter the endometrial epithelial adhesion, the initiating event of implantation, via the secretion of miR, abnormalities in which result in implantation failure.

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microRNAs are secreted by human blastocysts relative to implantation potential during IVF.

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microRNA-661 is secreted by blastocysts that fail to implant and taken up by endometrial epithelial cells via Argonaute 1.

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microRNA-661 reduces adhesion of trophoblast spheroids to endometrial cells.

Implantation failure is a large problem affecting the success rate of in vitro fertilisation (IVF). There are no effective treatments for implantation failure. Our study demonstrated that human embryos secrete microRNA and their expression is differentially expressed in embryos that achieve a successful pregnancy compared to embryos that fail. The study identified that microRNA 661 secreted by embryos, was taken up by human endometrial epithelial cells via attachment to a protein and inhibited endometrial cell adhesiveness. This suggests that abnormally produced microRNA may prevent attachment of human embryos to the endometrial lining and prevent implantation and pregnancy.

Expression of metastasis-associated protein 3 in human brain glioma related to tumor prognosis

Glioma represents a disparate group of tumors characterized by high invasion ability, and therefore it is of clinical significance to identify molecular markers and therapeutic targets for better clinical management. Previously, metastasis-associated protein family (MTA) is considered to promote tumor cell invasion and metastasis of human malignancies. Recently, the newly identified MTA3 has been shown to play conflicting roles in human malignancies, while the expression pattern and potential clinical significance of MTA3 in human glioma have not been addressed yet. In the present study, we investigated the protein expression of MTA3 by immunohistochemistry assay and analyzed its association with glioma prognosis in 186 cases of patients. Results showed that MTA3 expression was decreased in glioma compared with that in normal brain (P < 0.05). In addition, tumors with high MTA3 expression were more likely to be of low WHO grade (P = 0.005) and reserve of body function (P = 0.014). Survival analysis showed that decreased MTA3 expression was independently associated with unfavorable overall survival of patients (P < 0.001). These results provide the first evidence that MTA3 expression was decreased in human glioma and negatively associated with prognosis of patients, suggesting that MTA3 may play a tumor suppressor role in glioma.