Metastasis-associated Protein Research Articles

The Therapeutic Efficacy and Mechanism of Action of Gnetin C, a Natural Compound from the Melinjo Plant, in a Preclinical Mouse Model of Advanced Prostate Cancer.

The metastasis-associated protein 1/protein kinase B (MTA1/AKT) signaling pathway has been shown to cooperate in promoting prostate tumor growth. Targeted interception strategies by plant-based polyphenols, specifically stilbenes, have shown great promise against MTA1-mediated prostate cancer progression. In this study, we employed a prostate-specific transgenic mouse model with MTA1 overexpression on the background of phosphatase and tensin homolog (Pten) null (R26MTA1; Ptenf/f) and PC3M prostate cancer cells which recapitulate altered molecular pathways in advanced prostate cancer. Mechanistically, the MTA1 knockdown or pharmacological inhibition of MTA1 by gnetin C (dimer resveratrol) in cultured PC3M cells resulted in the marked inactivation of mammalian target of rapamycin (mTOR) signaling. In vivo, mice tolerated a daily intraperitoneal treatment of gnetin C (7 mg/kg bw) for 12 weeks without any sign of toxicity. Treatment with gnetin C markedly reduced cell proliferation and angiogenesis and promoted apoptosis in mice with advanced prostate cancer. Further, in addition to decreasing MTA1 levels in prostate epithelial cells, gnetin C significantly reduced mTOR signaling activity in prostate tissues, including the activity of mTOR-target proteins: p70 ribosomal protein S6 kinase (S6K) and eukaryotic translational initiation factor 4E (elF4E)-binding protein 1 (4EBP1). Collectively, these findings established gnetin C as a new natural compound with anticancer properties against MTA1/AKT/mTOR-activated prostate cancer, with potential as monotherapy and as a possible adjunct to clinically approved mTOR pathway inhibitors in the future.

Metastasis-associated protein 1 participates in regulating luminal acidification of the epididymis via repressing estrogen receptor alpha transcription.

As a component of the nucleosome remodeling and deacetylating (NuRD) complex, metastasis-associated protein 1 (MTA1) has been reported to be abundant in male reproductive system and might participate in spermatogenesis and sperm maturation, whereas the precise functional role of MTA1 in these processes is still undetermined. To investigate the effect and potential function of MTA1 in male fertility. Mta1 knockout mice (Mta1-/- ) were employed to detect their reproductive phenotype. The pH value of Mta1-/- epididymal luminal fluid was measured, and the potential mechanism of MTA1 involved in regulating luminal acidification was detected in vivo and in vitro. A vasectomy model with abnormal pH of epididymal lumen was established to further detect the effect of MTA1 on epididymal luminal microenvironment. Mta1-/- mice were fertile without any detectable defects in spermatogenesis or sperm motility while the deficiency of MTA1 could acidify the initial segment of epididymis to a certain extent. MTA1 could interact with estrogen receptor alpha (ERα) and inhibit the transcription of ERα target gene, hydrogen exchanger 3 (NHE3), and ultimately affect the epididymal luminal milieu. After vasectomy, the Mta1-/- mice presented a more acidic epididymal lumen which was closer to the normal state compared to the wild-type model. MTA1 is dispensable for male fertility in mice, but plays a potentially important function in regulating luminal acidification of the epididymis.

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.

Parthenolide inhibits the proliferation and migration of cervical cancer cells via FAK/GSK3β pathway.

Cervical cancer (CC) ranks as the fourth most prevalent malignancy among women worldwide, necessitating effective therapeutic interventions to mitigate its detrimental impact on both physical and mental health. Parthenolide (PTL), a natural product of the sesquiterpene lactone derived from Feverfew leaves, has exhibited promising anti-tumor properties in previous studies; however, its precise effects and underlying molecular mechanisms in CC remain elusive. In this work, we investigated the effect of PTL on the proliferation and migration of CC cells. Western blot analysis and Reverse transcription‑quantitative PCR were used for mechanistic elucidation. Our findings indicated that PTL substantially inhibited the proliferation of HeLa and SiHa CC cell lines in a dose- and time-dependent manner. Moreover, PTL significantly suppressed the migration of CC cells by down-regulating the expression of vascular endothelial growth factor (VEGF), metastasis-associated protein 1 (MTA1), and transforming growth factor-β1 (TGF-β1). Mechanistically, PTL blocked the phosphorylation of focal adhesion kinase (FAK) and glycogen synthase kinase-3β (GSK3β) induced by epidermal growth factor (EGF). Further investigations revealed that PTL suppressed the proliferation of CC cells by inhibiting the EGF-mediated phosphorylation of the FAK/GSK3β signaling pathway. Taken together, the present in vitro results suggest that PTL may inhibit the proliferation and migration of CC cells through down-regulating the FAK/GSK3β signaling pathway, providing new insights for the application of PTL in the treatment of CC.

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

Resistance of castrate-resistant prostate cancer (CRPC) to enzalutamide (Enz) involves the expression of constitutively active androgen receptor splice variant (AR-V7). In addition to altered AR pathways, CRPC is characterized by "non-AR-driven" signaling, which includes an overexpression of metastasis-associated protein 1 (MTA1). Combining natural compounds with anticancer drugs may enhance drug effectiveness while reducing adverse effects. In this study, the in vitro and in vivo anticancer effects of Gnetin C (GnC) alone and in combination with Enz against CRPC are examined. The effects of GnC alone and in combination with Enz are assessed by cell viability, clonogenic survival, cell migration, and AR and MTA1 expression using 22Rv1 cells. The tumor growth in vivo is assessed by bioluminescent imaging, western blots, RT-PCR, and IHC. GnC alone and in combined treatment inhibit cell viability, clonogenic survival and migration, and AR and MTA1 expression in 22Rv1 cells. The underlying AR- and MTA1-targeted anticancer mechanisms of treatments in vivo involve inhibition of proliferation and angiogenesis, and induction of apoptosis. The findings demonstrate that GnC alone and GnC combined with Enz effectively inhibits AR- and MTA1-promoted tumor-progression in advanced CRPC, which indicates its potential as a novel therapeutic approach for CRPC.

Nicotinic Acid-Mediated Modulation of Metastasis-Associated Protein 1 Methylation and Inflammation in Brain Arteriovenous Malformation.

We explored metastasis-associated protein 1 (MTA1) promoter methylation in the development of brain arteriovenous malformation (BAVM). The clinical data of 148 sex- and age-matched BAVMs and controls were collected, and the MTA1 DNA methylation in peripheral white blood cells (WBC) was assessed by bisulfite pyrosequencing. Among them, 18 pairs of case-control samples were used for WBC mRNA detection, 32 pairs were used for WBC MTA1 protein measurement, and 50 pairs were used for plasma inflammatory factor analysis. Lipopolysaccharide (LPS) treatment was used to induce an inflammatory injury cell model of human brain microvascular endothelial cells (BMECS). 5-Aza-2'-deoxycytidine (5-AZA), nicotinic acid (NA), and MTA1 siRNAs were used in functional experiments to examine BMECS behaviors. RT-qPCR, Western blot, and ELISA or cytometric bead arrays were used to measure the expression levels of MTA1, cytokines, and signaling pathway proteins in human blood or BMECS. The degree of MTA1 promoter methylation was reduced in BAVM compared with the control group and was inversely proportional to MTA1 expression. Plasma ApoA concentrations in BAVM patients were significantly lower than those in controls and correlated positively with MTA1 promoter methylation and negatively with MTA1 expression. The expression of cytokine was markedly higher in BAVM than in controls. Cell experiments showed that 5-AZA decreased the methylation level of MTA1 and increased the expression of MTA1 protein. LPS treatment significantly increased cytokine concentrations (p < 0.05). NA and MTA1 silencing could effectively reverse the LPS-mediated increase in IL-6 and TNF-α expression through the NF-κB pathway. Our study indicated that NA may regulate MTA1 expression by affecting promoter DNA methylation, improve vascular inflammation through the NF-κB pathway, and alleviate the pathological development of BAVM.

Effect of MTA3 Inhibition of Glutamine Synthetase-Mediated Glutaminolysis on Radiosensitivity of Patients with Esophageal Cancer

Metastasis-associated protein 3 (MTA3) can serve as a tumor suppressor in many cancer types. However, the role of MTA3 in radiosensitivity of patients with esophageal squamous cell cancer (ESCC) remains unclear. We thus investigated the function of MTA3 in radiosensitivity for ESCC, one of the most common digestive cancers. The colony formation assay and nude mice xenograft tumor assay were performed to investigate the effect of MTA3 on radiosensitivity in ESCC. Glutamine consumption assay kit and glutamate production assay kit were used to assess the glutaminolysis. Glutaminase (GLS) Activity Assay Kit and Glutamine Synthetase (GS) Activity Assay Kit were used to analyze the activity of specific metabolic enzymes dominate glutaminolysis. The regulatory mechanism of glutaminolysis by MTA3 was confirmed using Chromatin immunoprecipitation assay and Gaussia luciferase assay. The expression levels of MTA3 and GS in ESCC primary tissues were evaluated using immunohistochemistry. Survival curves were plotted with the Kaplan-Meier method and compared by log-rank test. The colony formation assay showed that MTA3 depletion and overexpression caused significantly higher and lower clonogenic survival after different doses of irradiation (IR), respectively. When these cells were subcutaneously injected into nude mice, the tumors derived from the cells with MTA3 overexpression and MTA3 knockdown were significantly smaller and bigger after IR, respectively. These findings suggest that MTA3 can enhance radiosensitivity in vitro and in vivo. Meanwhile, overexpressed and knockdown MTA3 can repress and expedite glutamine consumption and glutamate production uniformly, respectively. To determine how MTA3 acts on glutaminolysis, the activity of two specific metabolic enzymes dominate this metabolism, GS and GLS, were evaluated. It found that overexpressed and knockdown MTA3 can restrain and enhance the activity of GS, respectively, but have less effect on GLS. Moreover, the decreased radiosensitivity mediated by MTA3 knockdown is significantly increased when treated with GS inhibitor, suggesting that GS plays a crucial role in MTA3-mediated radiosensitivity enhancement. Mechanistically, Chromatin immunoprecipitation assay and Gaussia luciferase assay showed that MTA3 was recruited to the promoter of GS and suppressed GS transcription. However, knockdown of GATA3 abolished MTA3's repressive effect on GS and inhibited the MTA3's occupation on the promoter region of GS. These results collectively demonstrated that, in ESCC cells, MTA3 is recruited by GATA3 to inhibit GS expression, then ultimately represses glutaminolysis and enhances radiosensitivity. Finally, we showed that the ESCC patients in the MTA3low/GShigh group is significantly associated with shorter overall survival. MTA3 is capable of enhancing radiosensitivity through downregulating GS and MTA3low/GShigh might be a potential prognostic factor for ESCC patients.

JARID2 coordinates with the NuRD complex to facilitate breast tumorigenesis through response to adipocyte-derived leptin.

Proteins containing the Jumonji C (JmjC) domain participated in tumorigenesis and cancer progression. However, the mechanisms underlying this effect are still poorly understood. Our objective was to investigate the role of Jumonji and the AT-rich interaction domain-containing 2 (JARID2) - a JmjC family protein - in breast cancer, as well as its latent association with obesity. Immunohistochemistry, The Cancer Genome Atlas, Gene Expression Omnibus, and other databases were used to analyze the expression of JARID2 in breast cancer cells. Growth curve, 5-ethynyl-2-deoxyuridine (EdU), colony formation, and cell invasion experiments were used to detect whether JARID2 affected breast cancer cell proliferation and invasion. Spheroidization-based experiments and xenotumor transplantation in NOD/SCID mice were used to examine the association between JARID2 and breast cancer stemness. RNA-sequencing, Kyoto Encyclopedia of Genes and Genomes, and Gene Set Enrichment Analysis were used to identify the cell processes in which JARID2 participates. Immunoaffinity purification and silver staining mass spectrometry were conducted to search for proteins that might interact with JARID2. The results were further verified using co-immunoprecipitation and glutathione S-transferase (GST) pull-down experiments. Using chromatin immunoprecipitation (ChIP) sequencing, we sought the target genes that JARID2 and metastasis-associated protein 1 (MTA1) jointly regulated; the results were validated by ChIP-PCR, quantitative ChIP (qChIP) and ChIP-reChIP assays. A coculture experiment was used to explore the interactions between breast cancer cells and adipocytes. In this study, we found that JARID2 was highly expressed in multiple types of cancer including breast cancer. JARID2 promoted glycolysis, lipid metabolism, proliferation, invasion, and stemness of breast cancer cells. Furthermore, JARID2 physically interacted with the nucleosome remodeling and deacetylase (NuRD) complex, transcriptionally repressing a series of tumor suppressor genes such as BRCA2 DNA repair associated (BRCA2), RB transcriptional corepressor 1 (RB1), and inositol polyphosphate-4-phosphatase type II B (INPP4B). Additionally, JARID2 expression was regulated by the obesity-associated adipokine leptin via Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway in the breast cancer microenvironment. Analysis of various online databases also indicated that JARID2/MTA1 was associated with a poor prognosis of breast cancer. Our data indicated that JARID2 promoted breast tumorigenesis and development, confirming JARID2 as a target for cancer treatment.

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

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. 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. 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. 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.

CRISPR/Cas9 knockout of MTA1 enhanced RANKL-induced osteoclastogenesis in RAW264.7 cells partly via increasing ROS activities.

Metastasis-associated protein 1 (MTA1), belonging to metastasis-associated proteins (MTA) family, which are integral parts of nucleosome remodelling and histone deacetylation (NuRD) complexes. However, the effect of MTA1 on osteoclastogenesis is unknown. Currently, the regulation of MTA1 in osteoclastogenesis was reported for the first time. MTA1 knockout cells (KO) were established by CRISPR/Cas9 genome editing. RAW264.7 cells with WT and KO group were stimulated independently by RANKL to differentiate into mature osteoclasts. Further, western blotting and quantitative qRT-PCR were used to explore the effect of MTA1 on the expression of osteoclast-associated genes (including CTSK, MMP9, c-Fos and NFATc1) during osteoclastogenesis. Moreover, the effects of MTA1 on the expression of reactive oxygen species (ROS) in osteoclastogenesis was determined by 2', 7' -dichlorodihydrofluorescein diacetate (DCFH-DA) staining. Nuclear translocation of Nrf2 was assessed by immunofluorescence staining and western blotting. Our results indicated that the MTA1 deletion group could differentiate into osteoclasts with larger volume and more TRAP positive. In addition, compared with WT group, KO group cells generated more actin rings. Mechanistically, the loss of MTA1 increased the expression of osteoclast-specific markers, including c-Fos, NFATc1, CTSK and MMP-9. Furthermore, the results of qRT-PCR and western blotting showed that MTA1 deficiency reduced basal Nrf2 expression and inhibited Nrf2-mediated expression of related antioxidant enzymes. Immunofluorescence staining demonstrated that MTA1 deficiency inhibited Nrf2 nuclear translocation. Taken together, the above increased basal and RANKL-induced intracellular ROS levels, leading to enhanced osteoclast formation.

Stathmin1 promotes lymph node metastasis in hypopharyngeal squamous cell carcinoma via regulation of HIF‑1α/VEGF‑A axis and MTA1 expression.

Extensive neck lymph node metastasis (LNM) is an important clinical feature of hypopharyngeal squamous cell carcinoma (HSCC). Stathmin1 (STMN1) is closely associated with LNM in numerous human cancers. In the present study, the association between STMN1 and neck LNM in HSCC and the underlying molecular mechanisms were explored. First, postoperative samples of HSCC were screened and the association between STMN1 and neck LNM in HSCC was analyzed. Then, cell functional experiments were performed to assess the potential of STMN1 to promote invasion and migration. Subsequently, the potential target genes and pathways of STMN1 were predicted using bioinformatics analysis. Finally, the obtained target genes and pathways of STMN1 were validated by reverse transcription-quantitative PCR (RT-qPCR) and western blot analyses to confirm the potential mechanisms by which STMN1 promotes LNM in HSCC. As a result, a total of 117 postoperative samples of HSCC were screened, and STMN1 was proven to be associated with neck LNM in HSCC. Further, cell functional experiments established that high expression of STMN1 could actually promote FaDu cell invasion and metastasis. Bioinformatics analysis revealed that high expression of STMN1 was associated with the activation of hypoxia inducible factor-1alpha (HIF-1α) pathway and increased expression of metastasis-associated protein 1 (MTA1). Finally, RT-qPCR and western blot analyses confirmed that STMN1 promotes the expression levels of HIF-1α/vascular endothelial growth factor (VEGF)-A and MTA1 in FaDu cell lines. In conclusion, it was found that high expression of STMN1 promoted neck LNM in HSCC and the potential mechanisms may be via regulation of the HIF-1α/VEGF-A axis and MTA1 expression.

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.

Gnetin C Intercepts MTA1-Associated Neoplastic Progression in Prostate Cancer.

Nutritional chemoprevention is particularly suitable for prostate cancer. Gnetin C, a resveratrol dimer found abundantly in the melinjo plant (Gnetum gnemon), may possess more potent biological properties compared to other stilbenes. We examined the effects of gnetin C in a high-risk premalignant transgenic mouse model overexpressing tumor-promoting metastasis-associated protein 1 (MTA1) on the background of Pten heterozygosity (R26MTA1; Pten+/f; Pb-Cre+). Mice were fed diets supplemented with the following compounds: pterostilbene (70 mg/kg diet); gnetin C, high dose (70 mg/kg diet); and gnetin C, low dose (35 mg/kg diet). Prostate tissues were isolated after 17 weeks and examined for histopathology and molecular markers. Serum was analyzed for cytokine expression. Gnetin C-supplemented diets substantially delayed the progression of preneoplastic lesions compared to other groups. Prostate tissues from gnetin C-fed mice showed favorable histopathology, with decreased severity and number of prostatic intraepithelial neoplasia (PIN) foci, reduced proliferation, and angiogenesis. A decreased level of MTA1, concurrent with the trend of increasing phosphatase and tensin homolog expression and reduced interleukin 2 (IL-2) levels in sera, were also detected in gnetin C-fed mice. Importantly, gnetin C did not exert any visible toxicity in mice. Our findings demonstrate that a gnetin C-supplemented diet effectively blocks MTA1-promoted tumor progression activity in high-risk premalignant prostate cancer, which indicates its potential as a novel form of nutritional interception for prostate cancer chemoprevention.

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.

Evoking and enhancing ferroptosis of cancer stem cells by a liver-targeted and metal-organic framework-based drug delivery system inhibits the growth and lung metastasis of hepatocellular carcinoma

Evoking ferroptosis of cancer cells is a useful strategy to prevent tumor growth and metastasis. However, intrinsic ferroptosis suppressors glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1) compromise the efficacy of ferroptosis therapy. Herein, a Fe(III)-incorporated and metal–organic framework (MOF)-based drug delivery system is fabricated, loaded with small molecules RSL3 and iFSP1, and modified with liver-targeting ligand lactobionic acid. In hepatocellular carcinoma (HCC), Fe(III) of the as-synthesized RF@LA-Fe-MOF is reduced to Fe(II) by glutathione, initiating ferroptosis and disintegrating RF@LA-Fe-MOF to release RSL3 and iFSP1, which function as GPX4 inhibitor and FSP1 inhibitor, respectively. The simultaneous block of two ferroptosis suppressors largely enhances ferroptosis in HCC. Cell studies reveal potent proliferation-inhibiting and metastasis-blocking effects of RF@LA-Fe-MOF particularly toward HCC stem cells C5WN1, accompanied by decreased levels of GPX4 and FSP1 as well as augmented lipid peroxides accumulation. Moreover, RF@LA-Fe-MOF downregulates the expression of metastasis-associated protein Twist and alters the levels of epithelial-mesenchymal transition (EMT) related proteins. Treating subcutaneously HCC-bearing mice with RF@LA-Fe-MOF results in retarded tumor growth and prolonged life span. In an orthotopic C5WN1-bearing mice model, RF@LA-Fe-MOF shrinks tumor volume in liver and greatly inhibits tumor lung metastasis. The current work thus unprecedentedly achieves targeted induction and enhancement of ferroptosis in HCC by using a DDS containing two small-molecule ferroptosis boosters.

MTA1-TJP1 interaction and its involvement in non-small cell lung cancer metastasis

Distant metastasis is the main cause of death in non-small cell lung cancer (NSCLC) patients. The mechanism of metastasis-associated protein 1(MTA1) in NSCLC has not been fully elucidated. This study aimed to reveal the mechanism of MTA1 in the invasion and metastasis of NSCLC.Bioinformatics analysis and our previous results showed that MTA1 was highly expressed in NSCLC tissues and correlated with tumor progression. Knockout of MTA1 by CRISPR/Cas9 significantly inhibited the migration and invasion of H1299 cells, but enhanced cell adhesion. Stable overexpression of MTA1 by lentivirus transfection had opposite effects on migration, invasion and adhesion of A549 cells. The results of in vivo experiments in nude mouse lung metastases model confirmed the promotion of MTA1 on invasion and migration. Tight junction protein 1 (TJP1) was identified by immunoprecipitation and mass spectrometry as an interacting protein of MTA1 involved in cell adhesion. MTA1 inhibited the expression level of TJP1 protein and weakened the tight junctions between cells. More importantly, the rescue assays confirmed that the regulation of MTA1 on cell adhesion, migration and invasion was partially attenuated by TJP1.In Conclusion, MTA1 inhibits the expression level of TJP1 protein co-localized in the cytoplasm and membrane of NSCLC cells, weakens the tight junctions between cells, and changes the adhesion, migration and invasion capabilities of cells, which may be the mechanism of MTA1 promoting the invasion and metastasis of NSCLC. Thus, targeting the MTA1-TJP1 axis may be a promising strategy for inhibiting NSCLC metastasis.

MTA1 aggravates experimental colitis in mice by promoting transcription factor HIF1A and up-regulating AQP4 expression

Experimental colitis can persist as a chronic disease, accompanied with an underlying risk of development into colorectal cancer. Metastasis-associated protein 1 (MTA1), as a chromatin modifier, exerts notable association with multiple diseases, including colitis. The current study aims to investigate the mechanism of MTA1/HIF1A/AQP4 axis in experimental colitis in mice. First, experimental colitis mouse models were established using dextran sulfate sodium (DSS) and in vitro colonic epithelial cells FHC inflammation models were with lipopolysaccharide (LPS) for determination of MTA1 and HIF1A expressions. It was found that MTA1 and HIF1A were both highly-expressed in experimental colitis samples. Results of dual-luciferase reporter gene assay and ChIP assay further revealed that MTA1 activated HIF1A, and subsequently induced AQP4 transcription to up-regulate AQP4 in experimental colitis. Following loss- and gain-function, the effects of MTA1/HIF1A/AQP4 axis on apoptosis and viability of colon epithelial cells were detected by a combination of TUNEL staining and flow cytometry, and CCK-8 assay. It was observed that silencing of MAT1 in the FHC and NCM460 cells reduced IL-1β and TNF-α expressions induced by LPS. Meanwhile, AQP4 promoted LPS-induced inflammation, and exacerbated apoptosis of colon epithelial cells and augmented experimental colitis development in mice. In vivo experiments further verified that TGN-020 treatment effectively alleviated DSS-induced experimental colitis in mice and diminished apoptosis of colon epithelial cells. Altogether, MTA1 may promote AQP4 transcription by activating HIF1A, thus exacerbating DSS-induced experimental colitis in mice, which provides a novel direction for the treatment of experimental colitis.

Abstract 3374: Large-scale single-cell whole transcriptomic analyses reveal distinct malignant phenotypes of CTCs from NSCLC patients

Abstract Circulating tumor cells (CTC) hold great promise for representation of intratumoral heterogeneity and increasing our understanding of resistance mechanisms. However, especially in non-small cell lung cancer (NSCLC), numbers of CTCs detected and isolatable from peripheral blood samples using standard EPCAM-based techniques are too low to perform robust multi-omics analyses. Recent data suggested that diagnostic leukapheresis (DLA) can be used to increase CTC numbers by enriching them from larger blood volumes. Here, we present single-cell RNA sequencing data (scRNAseq) from 3172 NSCLC CTCs isolated by DLA. Between 3.1 and 8.0 liters of blood volume was processed with DLA and mononuclated cells were collected from six stage IV NSCLC patients. A total of 80x108 cells (≈33% of the DLA) were used for magnetic depletion of CD31+, CD3+, CD16+, CD235a+ and CD45+ cells followed by FACS sorting for CD45 negativity. Sorted cells were subjected to scRNAseq analysis using 10X Genomics. CTC transcriptomes were identified by marker gene expression (Satija Lab, US and R package SingleR). Gene set enrichment analysis (GSEA) on hallmark gene sets were performed to compare CTC transcriptomes and sc transcriptomes from primary NSCLC tumors. Unsupervised dimensional reduction and clustering revealed 7 distinct CTC cluster. Inferred copy number variation (CNV) analyses confirmed greater CNV variability compared to hematopoietic cells and a high degree of heterogeneity consistent with tumor cells. Also, CTC transcriptomes showed significantly higher expression of cancer-associated genes like Cyclin D1 and metastasis-associated protein 2 compared to normal hematopoietic cells. CTC clustering was independent of patient or histology, thus indicating a potential function-based clustering. Pseudotime analyses of all scCTC transcriptomes revealed three principal CTC phenotypes: (i) epithelial-like (expression of E-Cadherin), highly proliferative (expression of KI67 and E2F targets pathway) and immune responsive (enriched for IL1B, Interferon-α/γ-response pathways), (ii) mesenchymal/invasive (expression of Vimentin, mTORC1, hypoxia and glycolysis pathways) and (iii) mesenchymal/cancer stem cell-like (enrichment of genes including ALDH1A3 and oxidative phosphorylation and adipogenesis pathways). Compared to a set of scRNAseq data from primary NSCLC tumors (n=46), GSEA revealed an enrichment of pathways involved in cell cycle, anti-apoptosis and invasion in CTCs suggesting higher malignant potential compared to tissue-resident NSCLC tumor cells. Performing CTC enrichment using DLAs resulted in generation of an unprecedented number of transcriptomes from individual CTCs derived from NSCLC patients. Our data should lead to a better understanding of the heterogeneity of blood circulating CTCs and their associated biology and may allow rational design of CTC-targeting drugs. Citation Format: Lisa-Marie Rieckmann, Michael Spohn, Ekaterina Selbuz, Claudia Schubert, David Agorku, Lisa Becker, Alina Borchers, Jenny Krause, Lisa Ruff, Sarina Heinemann, Franca Kobus, Jurek Hille, Andia Louisa Tehrany, Janna-Lisa Velthaus-Rusik, Sören Franzenburg, Petros Christopoulos, Hauke Winter, Michael Thomas, Sabine Riethdorf, Nicola Gagliani, Carsten Bokemeyer, Christian F. Krebs, Martin Sprick, Andreas Trumpp, Sven Peine, Olaf Hardt, Nikolas H. Stoecklein, Klaus Pantel, Philipp Rosenstiel, Sonja Loges, Melanie Janning. Large-scale single-cell whole transcriptomic analyses reveal distinct malignant phenotypes of CTCs from NSCLC patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3374.

T2DM-elicited oxidative stress represses MTA3 expression in mouse Leydig cells.

Metastasis-associated protein 3 (MTA3) functions as a versatile coregulator in cancers and in physiological contexts. A predominant expression of MTA3 in interstitial Leydig cells (LCs) and its role as a local modulator of testicular steroidogenesis have recently emerged. Incubation with insulin decreased MTA3 expression in a concentration- and exposure time-dependent manner in LCs. This raises the possibility of additional endocrine actions of insulin in the direct control of MTA3 expression, which remains so far unexplored. Herein, we reported that type 2 diabetes mellitus (T2DM)-mediated inhibition of MTA3 was associated with an increase in testicular oxidative stress. In contrast, a gavage of the strong antioxidant melatonin effectively ameliorated oxidative stress and restored the expression of MTA3, but failed to change serum insulin levels in the diabetic mice with testosterone deficiency (TD). Using multiple biochemical approaches, we demonstrated that oxidative stress suppressed MTA3 expression via repression of nuclear receptor subfamily 4 group A member 1 (NR4A1)-mediated transactivation of MTA3 in mouse LCs. By contrast, ectopic expression of NR4A1 ameliorated oxidative stress-impaired MTA3 expression in LCs. By employing an effective in vivo gene transfer method with microinjection of lentiviral plasmids, we showed that replenishment of MTA3 expression in vivo partially restored testicular steroidogenesis and improved male fertility in diabetic mice with TD. Thus, we have unveiled a central regulatory hub, involving oxidative stress-impaired NR4A1-driven transactivation of MTA3 in stimulated LCs, as a potential mechanism regulating crosstalk between hyperinsulinemia and male infertility associated with TD.

Metastasis-associated protein 1: A potential driver and regulator of the hallmarks of cancer

Metastasis-associated protein 1 (MTA1) is an emerging transcriptional co-regulator and was found to be aberrantly expressed in different types of cancers. MTA1 has been reported to regulate multiple cancer-related signalling pathways leading to tumour progression and metastasis. Recently, MTA1 was also implicated in cancer metabolism, where it was found to regulate the 'Warburg effect' to drive breast cancer cell invasion. Overall, the functional dynamism of MTA1 can be attributed to its dual co-regulatory effects in regulating a diverse array of target genes involved in cell proliferation, DNA damage repair, angiogenesis, invasion, migration, metastasis, and metabolism in different types of cancers. In this review, we have attempted to provide a brief summary of MTA1 as a modulator of the hallmarks of cancer.