scholarly journals The autophagy protein Ambra1 regulates gene expression by supporting novel transcriptional complexes

2020 ◽  
Vol 295 (34) ◽  
pp. 12045-12057
Author(s):  
Christina Schoenherr ◽  
Adam Byron ◽  
Billie Griffith ◽  
Alexander Loftus ◽  
Jimi C. Wills ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cancer Cell ◽  
Cell Invasion ◽  
Cell Biology ◽  
Protein Complexes ◽  
Transcriptional Regulators ◽  
Adaptor Proteins ◽  
Nuclear Pore ◽  
Biochemical Fractionation

Ambra1 is considered an autophagy and trafficking protein with roles in neurogenesis and cancer cell invasion. Here, we report that Ambra1 also localizes to the nucleus of cancer cells, where it has a novel nuclear scaffolding function that controls gene expression. Using biochemical fractionation and proteomics, we found that Ambra1 binds to multiple classes of proteins in the nucleus, including nuclear pore proteins, adaptor proteins such as FAK and Akap8, chromatin-modifying proteins, and transcriptional regulators like Brg1 and Atf2. We identified biologically important genes, such as Angpt1, Tgfb2, Tgfb3, Itga8, and Itgb7, whose transcription is regulated by Ambra1-scaffolded complexes, likely by altering histone modifications and Atf2 activity. Therefore, in addition to its recognized roles in autophagy and trafficking, Ambra1 scaffolds protein complexes at chromatin, regulating transcriptional signaling in the nucleus. This novel function for Ambra1, and the specific genes impacted, may help to explain the wider role of Ambra1 in cancer cell biology.

scholarly journals A novel transcriptional signalling pathway mediated by the trafficking protein Ambra1 via scaffolding Atf2 complexes

2020 ◽  
Author(s):  
Christina Schoenherr ◽  
Adam Byron ◽  
Margaret C Frame
Keyword(s):  
Cell Invasion ◽  
Protein Complexes ◽  
Transcriptional Regulators ◽  
Adaptor Proteins ◽  
Nuclear Pore ◽  
Cancer Cell Invasion ◽  
Core Component ◽  
Expression Of Genes ◽  
Chromatin Modifiers

ABSTRACTPreviously, we reported that Ambra1 is a core component of a cytoplasmic trafficking network, acting as a spatial rheostat to control active Src and FAK levels in addition to its critical roles in autophagy during neurogenesis. Here we identify a novel nuclear scaffolding function for Ambra1 that controls gene expression. Ambra1 binds to nuclear pore proteins, to other adaptor proteins like FAK and Akap8 in the nucleus, as well as to chromatin modifiers and transcriptional regulators such as Brg1, Cdk9 and the cAMP-regulated transcription factor Atf2. Ambra1 contributes to their association with chromatin and we identified genes whose transcription is regulated by Ambra1 complexes, likely via histone modifications and phospho-Atf2-dependent transcription. Therefore, Ambra1 scaffolds protein complexes at chromatin, regulating transcriptional signalling in the nucleus; in particular, it recruits chromatin modifiers and transcriptional regulators to control expression of genes such as angpt1, tgfb2, tgfb3, itga8 and itgb7 that likely contribute to the role of Ambra1 in cancer cell invasion.

scholarly journals EB1 Restricts Breast Cancer Cell Invadopodia Formation and Matrix Proteolysis via FAK

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 388
Author(s):  
Brice Chanez ◽  
Kevin Ostacolo ◽  
Ali Badache ◽  
Sylvie Thuault
Keyword(s):  
Breast Cancer ◽  
Cancer Cell ◽  
Cell Invasion ◽  
Focal Adhesions ◽  
Matrix Degradation ◽  
Cancer Cell Invasion ◽  
Wild Type ◽  
Spatial Regulation ◽  
Invadopodia Formation

Regulation of microtubule dynamics by plus-end tracking proteins (+TIPs) plays an essential role in cancer cell migration. However, the role of +TIPs in cancer cell invasion has been poorly addressed. Invadopodia, actin-rich protrusions specialized in extracellular matrix degradation, are essential for cancer cell invasion and metastasis, the leading cause of death in breast cancer. We, therefore, investigated the role of the End Binding protein, EB1, a major hub of the +TIP network, in invadopodia functions. EB1 silencing increased matrix degradation by breast cancer cells. This was recapitulated by depletion of two additional +TIPs and EB1 partners, APC and ACF7, but not by the knockdown of other +TIPs, such as CLASP1/2 or CLIP170. The knockdown of Focal Adhesion Kinase (FAK) was previously proposed to similarly promote invadopodia formation as a consequence of a switch of the Src kinase from focal adhesions to invadopodia. Interestingly, EB1-, APC-, or ACF7-depleted cells had decreased expression/activation of FAK. Remarkably, overexpression of wild type FAK, but not of FAK mutated to prevent Src recruitment, prevented the increased degradative activity induced by EB1 depletion. Overall, we propose that EB1 restricts invadopodia formation through the control of FAK and, consequently, the spatial regulation of Src activity.

The role of miR-205 in the VEGF-mediated promotion of human ovarian cancer cell invasion

2015 ◽  
Vol 137 (1) ◽  
pp. 125-133 ◽  
Author(s):  
Juanni Li ◽  
Long Li ◽  
Zexia Li ◽  
Guanghui Gong ◽  
Puxiang Chen ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cell ◽  
Cell Invasion ◽  
Ovarian Cancer Cell ◽  
Human Ovarian Cancer ◽  
Cancer Cell Invasion ◽  
Human Ovarian Cancer Cell

scholarly journals The Role of WAVE2 Signaling in Cancer

Biomedicines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1217
Author(s):  
Priyanka Shailendra Rana ◽  
Akram Alkrekshi ◽  
Wei Wang ◽  
Vesna Markovic ◽  
Khalid Sossey-Alaoui
Keyword(s):  
Actin Cytoskeleton ◽  
Cancer Cell ◽  
Cell Invasion ◽  
Critical Role ◽  
Therapeutic Strategies ◽  
Small Gtpases ◽  
Cancer Cell Invasion ◽  
Invasion And Metastasis ◽  
Regulatory Complex

The Wiskott–Aldrich syndrome protein (WASP) and WASP family verprolin-homologous protein (WAVE)—WAVE1, WAVE2 and WAVE3 regulate rapid reorganization of cortical actin filaments and have been shown to form a key link between small GTPases and the actin cytoskeleton. Upon receiving upstream signals from Rho-family GTPases, the WASP and WAVE family proteins play a significant role in polymerization of actin cytoskeleton through activation of actin-related protein 2/3 complex (Arp2/3). The Arp2/3 complex, once activated, forms actin-based membrane protrusions essential for cell migration and cancer cell invasion. Thus, by activation of Arp2/3 complex, the WAVE and WASP family proteins, as part of the WAVE regulatory complex (WRC), have been shown to play a critical role in cancer cell invasion and metastasis, drawing significant research interest over recent years. Several studies have highlighted the potential for targeting the genes encoding either part of or a complete protein from the WASP/WAVE family as therapeutic strategies for preventing the invasion and metastasis of cancer cells. WAVE2 is well documented to be associated with the pathogenesis of several human cancers, including lung, liver, pancreatic, prostate, colorectal and breast cancer, as well as other hematologic malignancies. This review focuses mainly on the role of WAVE2 in the development, invasion and metastasis of different types of cancer. This review also summarizes the molecular mechanisms that regulate the activity of WAVE2, as well as those oncogenic pathways that are regulated by WAVE2 to promote the cancer phenotype. Finally, we discuss potential therapeutic strategies that target WAVE2 or the WAVE regulatory complex, aimed at preventing or inhibiting cancer invasion and metastasis.

MATHEMATICAL MODELLING OF CANCER CELL INVASION OF TISSUE: THE ROLE OF THE UROKINASE PLASMINOGEN ACTIVATION SYSTEM

2005 ◽  
Vol 15 (11) ◽  
pp. 1685-1734 ◽  
Author(s):  
M. A. J. CHAPLAIN ◽  
G. LOLAS
Keyword(s):  
Cancer Cells ◽  
Cancer Cell ◽  
Cell Invasion ◽  
The Body ◽  
Plasminogen Activation ◽  
Cancer Cell Invasion ◽  
Plasminogen Activation System ◽  
Activation System ◽  
Spatio Temporal

The growth of solid tumours proceeds through two distinct phases: the avascular and the vascular phase. It is during the latter stage that the insidious process of cancer invasion of peritumoral tissue can and does take place. Vascular tumours grow rapidly allowing the cancer cells to establish a new colony in distant organs, a process that is known as metastasis. The progression from a single, primary tumour to multiple tumours in distant sites throughout the body is known as the metastatic cascade. This is a multistep process that first involves the over-expression by the cancer cells of proteolytic enzyme activity, such as the urokinase-type plasminogen activator (uPA) and matrix metalloproteinases (MMPs). uPA itself initiates the activation of an enzymatic cascade that primarily involves the activation of plasminogen and subsequently its matrix degrading protein plasmin. Degradation of the matrix then enables the cancer cells to migrate through the tissue and subsequently to spread to secondary sites in the body. In this paper we consider a mathematical model of cancer cell invasion of tissue (extracellular matrix) which focuses on the role of the plasminogen activation system. The model consists of a system of reaction-diffusion-taxis partial differential equations describing the interactions between cancer cells, urokinase plasminogen activator (uPA), uPA inhibitors, plasmin and the host tissue. The focus of the modelling is on the spatio-temporal dynamics of the uPA system and how this influences the migratory properties of the cancer cells through random motility, chemotaxis and haptotaxis. The results obtained from numerical computations carried out on the model equations produce rich, dynamic heterogeneous spatio-temporal solutions and demonstrate the ability of rather simple models to produce complicated dynamics, all of which are associated with tumour heterogeneity and cancer cell progression and invasion.

scholarly journals Prefoldins contribute to maintaining the levels of the spliceosome LSM2–8 complex through Hsp90 in Arabidopsis

2020 ◽  
Vol 48 (11) ◽  
pp. 6280-6293 ◽  
Author(s):  
David Esteve-Bruna ◽  
Cristian Carrasco-López ◽  
Noel Blanco-Touriñán ◽  
Javier Iserte ◽  
Julián Calleja-Cabrera ◽  
...  
Keyword(s):  
Gene Expression ◽  
Model Organism ◽  
Transcriptional Regulators ◽  
Hsp90 Inhibitor ◽  
Mrna Splicing ◽  
Core Complex ◽  
Functional Specificity ◽  
U6 Snrna ◽  
Splicing Patterns

Abstract Although originally identified as the components of the complex aiding the cytosolic chaperonin CCT in the folding of actins and tubulins in the cytosol, prefoldins (PFDs) are emerging as novel regulators influencing gene expression in the nucleus. Work conducted mainly in yeast and animals showed that PFDs act as transcriptional regulators and participate in the nuclear proteostasis. To investigate new functions of PFDs, we performed a co-expression analysis in Arabidopsis thaliana. Results revealed co-expression between PFD and the Sm-like (LSM) genes, which encode the LSM2–8 spliceosome core complex, in this model organism. Here, we show that PFDs interact with and are required to maintain adequate levels of the LSM2–8 complex. Our data indicate that levels of the LSM8 protein, which defines and confers the functional specificity of the complex, are reduced in pfd mutants and in response to the Hsp90 inhibitor geldanamycin. We provide biochemical evidence showing that LSM8 is a client of Hsp90 and that PFD4 mediates the interaction between both proteins. Consistent with our results and with the role of the LSM2–8 complex in splicing through the stabilization of the U6 snRNA, pfd mutants showed reduced levels of this snRNA and altered pre-mRNA splicing patterns.

scholarly journals The emerging role of circular RNAs in breast cancer

2019 ◽  
Vol 39 (6) ◽  
Author(s):  
Si-ying Zhou ◽  
Wei Chen ◽  
Su-jin Yang ◽  
Zi-han Xu ◽  
Jia-hua Hu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Cell Invasion ◽  
Clinical Characteristics ◽  
Circular Rnas ◽  
Rnase R ◽  
New Class ◽  
Regulatory Rnas ◽  
And Function

AbstractBreast cancer (BCa) is one of the most frequently diagnosed cancers and leading cause of cancer deaths among females worldwide. Circular RNAs (circRNAs) are a new class of endogenous regulatory RNAs characterized by circular shape resulting from covalently closed continuous loops that are capable of regulating gene expression at transcription or post-transcription levels. With the unique structures, circRNAs are resistant to exonuclease RNase R and maintain stability more easily than linear RNAs. Recently, an increasing number of circRNAs are discovered and reported to show different expression in BCa and these dysregulated circRNAs were correlated with patients’ clinical characteristics and grade in the progression of BCa. CircRNAs participate in the bioprocesses of carcinogenesis of BCa, including cell proliferation, apoptosis, cell cycle, tumorigenesis, vascularization, cell invasion, migration as well as metastasis. Here we concentrated on biogenesis and function of circRNAs, summarized their implications in BCa and discussed their potential as diagnostic and therapeutic targets for BCa.

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