MT1-MMP prevents growth inhibition by three dimensional fibronectin matrix

The extracellular microenvironment plays a key role in regulation of cellular functions and growth control. We show here that membrane-type 1 matrix metalloproteinase (MT1-MMP) acts as a growth promoter in confluent culture. When MT1-MMP was silenced in HT1080 fibrosarcoma cells, cells created three dimensional (3D) fibronectin matrix in a confluent culture, and growth of cells embedded within it was retarded. Formation of 3D fibronectin matrix initiated by MT1-MMP silencing was impeded by knockdown of either FN or integrin β1, which resulted in restoration of cell growth. When cells in 3D fibronectin matrix were treated with integrin β1 inhibitory antibody, cells underwent S phase entry. These results suggest that MT1-MMP prevents growth suppression by 3D fibronectin matrix, which is mediated through integrin β1. © 2013 Elsevier Inc

Cleavage of hepatocyte growth factor activator inhibitor-1 by membrane-type MMP-1 activates matriptase

Co-expression of membrane-type 1 (MT1)-MMP with hepatocyte growth factor activator inhibitor-1 (HAI-1) in HEK293T cells resulted in cleavage of HAI-1 to produce three fragments. Recombinant MT1-MMP was shown to cleave HAI-1 protein in vitro. Hepatocyte growth factor activator inhibitor-1 was initially identified as the cognate inhibitor of matriptase, a transmembrane serine protease that processes urokinase-type plasminogen activator (uPA). Co-expression of HAI-1 with matriptase suppressed matriptase protease activity, and co-expression of MT1-MMP with them resulted in recovery of matriptase activity by stimulating shedding of HAI-1 fragments. Matriptase protein was detected in squamous carcinoma-derived HSC-4 cells, however, matriptase protease activity was undetectable. Transfection of siRNA for HAI-1 enhanced serine protease activity, which was suppressed by cotransfection of matriptase siRNA. Collagen-gel culture or treatment with concanavalin A (ConA) of HSC-4 cells enhanced MT1-MMP activity, which induced shedding of HAI-1 fragments and conversely stimulated uPA activation by these cells. Serine protease activity, including uPA activation of cells treated with ConA, was abrogated by downregulation of either matriptase or MT1-MMP through the transfection of each siRNA. These results suggest that MT1-MMP induced by collagen-gel culture or ConA treatment causes cleavage and shedding of HAI-1 protein, which allows activation of matriptase in HSC-4 cells. HSC-4 cells showed a characteristic invasive growth by forming vacuole-like structures in collagen gel, which was suppressed by transfection of siRNA for either MT1-MMP or matriptase, suggesting that activation of matriptase through the cleavage of HAI-1 is one of the MT1-MMP multifunctions essential for invasive growth of HSC-4 cells. © 2011 Japanese Cancer Association

Vinculin negatively regulates transcription of MT1-MMP through MEK/ERK pathway

Vinculin regulates a variety of cellular functions partly through stabilization of tumor suppressor PTEN. In order to study the role of vinculin in tumor progression other than PTEN stabilization, vinculin was knocked down in PTEN-deficient squamous cell carcinoma HSC-4 cells. Knockdown of vinculin induced phenotypical change by reducing cell-cell and cell-extracellular matrix adhesions, and enhanced MT1-MMP expression at transcription level and subsequent cell migration. Up-regulation of MT1-MMP transcription by vinculin knockdown was abrogated by ERK inhibition. These results suggest that vinculin negatively regulates malignant phenotype of tumor cells including MT1-MMP transcription through MEK/ERK pathway

Tip60 regulates MT1-MMP transcription and invasion of glioblastoma cells through NF-κB pathway

A histone acetyltransferase Tat-interacting protein 60 kDa (Tip60) regulates the DNA damage response by acetylating histone and remodeling chromatin. In addition to histone acetyltransferase activity, Tip60 is known to regulate a variety of cellular functions, including gene expression, DNA damage response, cell migration and apoptosis. Lower expression of Tip60 is observed in lymphomas, melanomas, breast, colon, and lung cancer. It is widely accepted that Tip60 functions as a tumor suppressor. However, a role of Tip60 in gliomas still remains unclear. In this study, we investigated the role of Tip60 in the malignant behavior of human gliomas. By quantitative RT-PCR analysis using fresh human brain tumor tissues from 55 patients, we found that lower Tip60 expression and higher membrane-type 1 matrix metalloproteinase (MT1-MMP) expression are associated with advanced tumor grade in glioma tissues. Knockdown of Tip60 in glioblastoma cells promoted cell adhesion, spreading and MT1-MMP transcription and thereby invasion, which was suppressed by inhibition of MT1-MMP and nuclear factor-kappa B (NF-κB) activity. We demonstrate for the first time that tumor suppressor Tip60 down-regulates cell adhesion and MT1-MMP expression and thereby invasion of glioblastoma cells by suppressing NF-κB pathway. © 2015, Springer Science+Business Media Dordrecht.Embargo Period 12 month

Membrane-type 1 matrix metalloproteinase regulates fibronectin assembly and N-cadherin adhesion

Fibronectin matrix formation requires the increased cytoskeletal tension generated by cadherin adhesions, and is suppressed by membrane-type 1 matrix metalloproteinase (MT1-MMP). In a co-culture of Rat1 fibroblasts and MT1-MMP-silenced HT1080 cells, fibronectin fibrils extended from Rat1 to cell-matrix adhesions in HT1080 cells, and N-cadherin adhesions were formed between Rat1 and HT1080 cells. In control HT1080 cells contacting with Rat1 fibroblasts, cell-matrix adhesions were formed in the side away from Rat1 fibroblasts, and fibronectin assembly and N-cadherin adhesions were not formed. The role of N-cadherin adhesions in fibronectin matrix formation was studied using MT1-MMP-silenced HT1080 cells. MT1-MMP knockdown promoted fibronectin matrix assembly and N-cadherin adhesions in HT1080 cells, which was abrogated by double knockdown with either integrin β1 or fibronectin. Conversely, inhibition of N-cadherin adhesions by its knockdown or treatment with its neutralizing antibody suppressed fibronectin matrix formation in MT1-MMP-silenced cells. These results demonstrate that fibronectin assembly initiated by MT1-MMP knockdown results in increase of N-cadherin adhesions, which are prerequisite for further fibronectin matrix formation. © 2014 Elsevier Inc. All rights reserved

Glycogen synthase kinase-3β is a pivotal mediator of cancer invasion and resistance to therapy

Tumor cell invasion and resistance to therapy are the most intractable biological characteristics of cancer and, therefore, the most challenging for current cancer research and treatment paradigms. Refractory cancers, including pancreatic cancer and glioblastoma, show an inextricable association between the highly invasive behavior of tumor cells and their resistance to chemotherapy, radiotherapy and targeted therapies. These aggressive properties of cancer share distinct cellular pathways that are connected to each other by several molecular hubs. There is increasing evidence to show that glycogen synthase kinase (GSK)-3β is aberrantly activated in various cancer types and this has emerged as a potential therapeutic target. In many but not all cancer types, aberrant GSK3β sustains the survival, immortalization, proliferation and invasion of tumor cells, while also rendering them insensitive or resistant to chemotherapeutic agents and radiation. Here we review studies that describe associations between therapeutic stimuli/resistance and the induction of pro-invasive phenotypes in various cancer types. Such cancers are largely responsive to treatment that targets GSK3β. This review focuses on the role of GSK3β as a molecular hub that connects pathways responsible for tumor invasion and resistance to therapy, thus highlighting its potential as a major cancer therapeutic target. We also discuss the putative involvement of GSK3β in determining tumor cell stemness that underpins both tumor invasion and therapy resistance, leading to intractable and refractory cancer with dismal patient outcomes. © 2016 Japanese Cancer Association.(Please refer to a different file for the Supporting information of this article.

GI24 enhances tumor invasiveness by regulating cell surface membrane-type 1 matrix metalloproteinase

GI24, an immunoglobulin superfamily member, has been cloned from a placenta cDNA library as a gene product that promoted activation of matrix metalloproteinase (MMP)-2 mediated by membrane type (MT) 1-MMP. Co-expression of GI24 with MT1-MMP in HEK293T cells increased the cell-surface level of MT1-MMP concomitant with the cleavage of the GI24 at the juxtamembrane site to shed the extracellular domain. HT1080 fibrosarcoma cells stably transfected with the GI24 gene expressed a higher level of MT1-MMP and showed more invasive ability in collagen gel than the control cells. GI24 was cleaved in HT1080 cells, which was blocked by the administration of MMP inhibitor BB94 or transfection of small interfering RNA (siRNA) targeting MT1-MMP. GI24 expression is relatively high in some squamous carcinoma and hepatocarcinoma cell lines. Transfection of siRNA for GI24 into oral squamous carcinoma-derived HSC-4 cells, which express GI24 and MT1-MMP genes reduced the expression of not only GI24 but also MT1-MMP, and attenuated invasive growth in the collagen matrix. These results suggest that GI24 contributes to tumor-invasive growth in the collagen matrix by augmenting cell surface MT1-MMP. (Cancer Sci 2010; 101: 2368-2374) © 2010 Japanese Cancer Association

Colorectal cancer cells require glycogen synthase kinase-3β for sustaining mitosis via translocated promoter region (TPR)- dynein interaction

金沢大学がん進展制御研究所Glycogen synthase kinase (GSK) 3β, which mediates fundamental cellular signaling pathways, has emerged as a potential therapeutic target for many types of cancer including colorectal cancer (CRC). During mitosis, GSK3β localizes in mitotic spindles and centrosomes, however its function is largely unknown. We previously demonstrated that translocated promoter region (TPR, a nuclear pore component) and dynein (a molecular motor) cooperatively contribute to mitotic spindle formation. Such knowledge encouraged us to investigate putative functional interactions among GSK3β, TPR, and dynein in the mitotic machinery of CRC cells. Here, we show that inhibition of GSK3β attenuated proliferation, induced cell cycle arrest at G2/M phase, and increased apoptosis of CRC cells. Morphologically, GSK3β inhibition disrupted chromosome segregation, mitotic spindle assembly, and centrosome maturation during mitosis, ultimately resulting in mitotic cell death. These changes in CRC cells were associated with decreased expression of TPR and dynein, as well as disruption of their functional colocalization with GSK3β in mitotic spindles and centrosomes. Clinically, we showed that TPR expression was increased in CRC databases and primary tumors of CRC patients. Furthermore, TPR expression in SW480 cells xenografted into mice was reduced following treatment with GSK3β inhibitors. Together, these results indicate that GSK3β sustains steady mitotic processes for proliferation of CRC cells via interaction with TPR and dynein, thereby suggesting that the therapeutic effect of GSK3β inhibition depends on induction of mitotic catastrophe in CRC cells. © Dewi et al.出版社

Poster Session

International Symposium on Tumor Biology in Kanazawa & Symposium on Drug Discoverry in Academics 2014 [DATE]: January 23(Thu)-24(Fri),2014, [Place]:Kanazawa Excel Hotel Tpkyu, Kanazawa, Japan, [Organizers]:Kanazawa Association of Tumor Biologists / Cancer Research Institute, Kanazawa Universit