scholarly journals HDAC8 suppresses the epithelial phenotype and promotes EMT in chemotherapy-treated basal-like breast cancer

2022 ◽  
Vol 14 (1) ◽  
Author(s):  
Garyfallia Pantelaiou-Prokaki ◽  
Iga Mieczkowska ◽  
Geske E. Schmidt ◽  
Sonja Fritzsche ◽  
Evangelos Prokakis ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Transcription Factors ◽  
Tumor Cells ◽  
Cell Phenotype ◽  
Cancer Resistance ◽  
Conventional Chemotherapy ◽  
Mesenchymal Transition ◽  
Chip Sequencing ◽  
Epithelial Phenotype ◽  
Basal Like Breast Cancer

Abstract Background Basal-like breast cancer (BLBC) is one of the most aggressive malignant diseases in women with an increased metastatic behavior and poor prognosis compared to other molecular subtypes of breast cancer. Resistance to chemotherapy is the main cause of treatment failure in BLBC. Therefore, novel therapeutic strategies counteracting the gain of aggressiveness underlying therapy resistance are urgently needed. The epithelial-to-mesenchymal transition (EMT) has been established as one central process stimulating cancer cell migratory capacity but also acquisition of chemotherapy-resistant properties. In this study, we aimed to uncover epigenetic factors involved in the EMT-transcriptional program occurring in BLBC cells surviving conventional chemotherapy. Results Using whole transcriptome data from a murine mammary carcinoma cell line (pG-2), we identified upregulation of Hdac4, 7 and 8 in tumor cells surviving conventional chemotherapy. Subsequent analyses of human BLBC patient datasets and cell lines established HDAC8 as the most promising factor sustaining tumor cell viability. ChIP-sequencing data analysis identified a pronounced loss of H3K27ac at regulatory regions of master transcription factors (TFs) of epithelial phenotype like Gata3, Elf5, Rora and Grhl2 upon chemotherapy. Interestingly, impairment of HDAC8 activity reverted epithelial-TFs levels. Furthermore, loss of HDAC8 activity sensitized tumor cells to chemotherapeutic treatments, even at low doses. Conclusion The current study reveals a previously unknown transcriptional repressive function of HDAC8 exerted on a panel of transcription factors involved in the maintenance of epithelial cell phenotype, thereby supporting BLBC cell survival to conventional chemotherapy. Our data establish HDAC8 as an attractive therapeutically targetable epigenetic factor to increase the efficiency of chemotherapeutics. Graphical abstract

scholarly journals Decreased PRC2 activity supports the survival of basal-like breast cancer cells to cytotoxic treatments

2021 ◽  
Vol 12 (12) ◽  
Author(s):  
Iga K. Mieczkowska ◽  
Garyfallia Pantelaiou-Prokaki ◽  
Evangelos Prokakis ◽  
Geske E. Schmidt ◽  
Lukas C. Müller-Kirschbaum ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Drug Targets ◽  
Epithelial To Mesenchymal Transition ◽  
Therapeutic Potential ◽  
Therapy Resistance ◽  
Epigenetic Switch ◽  
Mesenchymal Transition ◽  
Chip Sequencing ◽  
Development Of Resistance ◽  
Basal Like Breast Cancer

AbstractBreast cancer (BC) is the most common cancer occurring in women but also rarely develops in men. Recent advances in early diagnosis and development of targeted therapies have greatly improved the survival rate of BC patients. However, the basal-like BC subtype (BLBC), largely overlapping with the triple-negative BC subtype (TNBC), lacks such drug targets and conventional cytotoxic chemotherapies often remain the only treatment option. Thus, the development of resistance to cytotoxic therapies has fatal consequences. To assess the involvement of epigenetic mechanisms and their therapeutic potential increasing cytotoxic drug efficiency, we combined high-throughput RNA- and ChIP-sequencing analyses in BLBC cells. Tumor cells surviving chemotherapy upregulated transcriptional programs of epithelial-to-mesenchymal transition (EMT) and stemness. To our surprise, the same cells showed a pronounced reduction of polycomb repressive complex 2 (PRC2) activity via downregulation of its subunits Ezh2, Suz12, Rbbp7 and Mtf2. Mechanistically, loss of PRC2 activity leads to the de-repression of a set of genes through an epigenetic switch from repressive H3K27me3 to activating H3K27ac mark at regulatory regions. We identified Nfatc1 as an upregulated gene upon loss of PRC2 activity and directly implicated in the transcriptional changes happening upon survival to chemotherapy. Blocking NFATc1 activation reduced epithelial-to-mesenchymal transition, aggressiveness, and therapy resistance of BLBC cells. Our data demonstrate a previously unknown function of PRC2 maintaining low Nfatc1 expression levels and thereby repressing aggressiveness and therapy resistance in BLBC.

scholarly journals Distinct Ring1b complexes defined by DEAD-box helicases and EMT transcription factors synergistically enhance E-cadherin silencing in breast cancer

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Yawei Wang ◽  
Yingying Sun ◽  
Chao Shang ◽  
Lili Chen ◽  
Hongyu Chen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Transcription Factors ◽  
Cancer Cells ◽  
Epithelial Mesenchymal Transition ◽  
Epigenetic Mechanism ◽  
Regulation Mechanism ◽  
Rna Helicases ◽  
Mesenchymal Transition ◽  
Dead Box ◽  
E Cadherin

AbstractRing1b is a core subunit of polycomb repressive complex 1 (PRC1) and is essential in several high-risk cancers. However, the epigenetic mechanism of Ring1b underlying breast cancer malignancy is poorly understood. In this study, we showed increased expression of Ring1b promoted metastasis by weakening cell–cell adhesions of breast cancer cells. We confirmed that Ring1b could downregulate E-cadherin and contributed to an epigenetic rewiring via PRC1-dependent function by forming distinct complexes with DEAD-box RNA helicases (DDXs) or epithelial-mesenchymal transition transcription factors (EMT TFs) on site-specific loci of E-cadherin promoter. DDXs-Ring1b complexes moderately inhibited E-cadherin, which resulted in an early hybrid EMT state of epithelial cells, and EMT TFs-Ring1b complexes cooperated with DDXs-Ring1b complexes to further repress E-cadherin in mesenchymal-like cancer cells. Clinically, high expression of Ring1b with DDXs or EMT TFs predicted low levels of E-cadherin, metastatic behavior, and poor prognosis. These findings provide an epigenetic regulation mechanism of Ring1b complexes in E-cadherin expression. Ring1b complexes may be potential therapeutic targets and biomarkers for diagnosis and prognosis in invasion breast cancer.

scholarly journals Matrix metalloproteinases in the process of invasion and metastasis of breast cancer

2006 ◽  
Vol 14 (3-4) ◽  
pp. 136-140 ◽  
Author(s):  
Gordana Konjevic ◽  
Sandra Stankovic
Keyword(s):  
Breast Cancer ◽  
Matrix Metalloproteinases ◽  
Tumor Progression ◽  
Tumor Cells ◽  
Proteolytic Enzymes ◽  
Tissue Inhibitors Of Metalloproteinases ◽  
Collagen Type Iv ◽  
Cell Contact ◽  
Invasion And Metastasis ◽  
Mesenchymal Transition

Metastatic cascade in malignant tumors, including breast cancer, starts with localized invasion of the host tissue. This process, requiring that tumor cells separate from each other, includes loss of homotypic and heterotypic cell adhesion and cell-cell contact inhibition, acquisition of motility, exacerbated by "epithelial-to-mesenchymal transition", and production of proteolytic enzymes which degrade basal membrane and extracellular matrix. In this sense, aside from urokinase type plasminogen activator, increased expression and activity of matrix metalloproteinases (MMPs) is one of the earliest and most sustained events in tumor progression, playing a role in angiogenesis, invasion and metastasis. MMPs are a family of 23 zinc metalloproteinases, secreted as latent pro-enzymes, activated by proteolytic cleavage, and inhibited by the tissue inhibitors of metalloproteinases. The most commonly connected MMPs with the processes of metastasis are MMP-2 (gelatinase A) and MMP-9 (gelatinase B), due to their ability to degrade collagen type IV, major component of vascular basement membrane. MMP-2 and MMP-9 are also required for the switch to the "angiogenic phenotype" during tumor progression and activation of dormant tumor cells. The association of the increase in serum MMP-2 and MMP-9 activity and clinical stage suggests the usefulness of these parameters as markers in the follow-up and prognosis of breast cancer patients. The concept of "stromal-directed therapy" of cancer, with MMP-inhibitors directed against MMPs as targets, is based on the observed MMP up-regulation in tumors.

scholarly journals Oncogenic Metabolism Acts as a Prerequisite Step for Induction of Cancer Metastasis and Cancer Stem Cell Phenotype

2018 ◽  
Vol 2018 ◽  
pp. 1-28 ◽  
Author(s):  
Su Yeon Lee ◽  
Min Kyung Ju ◽  
Hyun Min Jeon ◽  
Yig Ji Lee ◽  
Cho Hee Kim ◽  
...  
Keyword(s):  
Stem Cell ◽  
Transcription Factors ◽  
Cancer Stem Cell ◽  
Tumor Progression ◽  
Cancer Cells ◽  
Cancer Metastasis ◽  
Metabolic Reprogramming ◽  
Glutamine Metabolism ◽  
Cell Phenotype ◽  
Mesenchymal Transition

Metastasis is a major obstacle to the efficient and successful treatment of cancer. Initiation of metastasis requires epithelial-mesenchymal transition (EMT) that is regulated by several transcription factors, including Snail and ZEB1/2. EMT is closely linked to the acquisition of cancer stem cell (CSC) properties and chemoresistance, which contribute to tumor malignancy. Tumor suppressor p53 inhibits EMT and metastasis by negatively regulating several EMT-inducing transcription factors and regulatory molecules; thus, its inhibition is crucial in EMT, invasion, metastasis, and stemness. Metabolic alterations are another hallmark of cancer. Most cancer cells are more dependent on glycolysis than on mitochondrial oxidative phosphorylation for their energy production, even in the presence of oxygen. Cancer cells enhance other oncogenic metabolic pathways, such as glutamine metabolism, pentose phosphate pathway, and the synthesis of fatty acids and cholesterol. Metabolic reprogramming in cancer is regulated by the activation of oncogenes or loss of tumor suppressors that contribute to tumor progression. Oncogenic metabolism has been recently linked closely with the induction of EMT or CSC phenotypes by the induction of several metabolic enzyme genes. In addition, several transcription factors and molecules involved in EMT or CSCs, including Snail, Dlx-2, HIF-1α, STAT3, TGF-β, Wnt, and Akt, regulate oncogenic metabolism. Moreover, p53 induces metabolic change by directly regulating several metabolic enzymes. The collective data indicate the importance of oncogenic metabolism in the regulation of EMT, cell invasion and metastasis, and adoption of the CSC phenotype, which all contribute to malignant transformation and tumor development. In this review, we highlight the oncogenic metabolism as a key regulator of EMT and CSC, which is related with tumor progression involving metastasis and chemoresistance. Targeting oncometabolism might be a promising strategy for the development of effective anticancer therapy.

scholarly journals EMT Regulation by Autophagy: A New Perspective in Glioblastoma Biology

Cancers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 312 ◽  
Author(s):  
Barbara Colella ◽  
Fiorella Faienza ◽  
Sabrina Di Bartolomeo
Keyword(s):  
Transcription Factors ◽  
Tumor Cells ◽  
Tissue Repair ◽  
Epithelial To Mesenchymal Transition ◽  
Signalling Pathways ◽  
Migration And Invasion ◽  
Cell Resistance ◽  
Mesenchymal Phenotype ◽  
Mesenchymal Transition ◽  
New Perspective

Epithelial-to-mesenchymal transition (EMT) and its reverse process MET naturally occur during development and in tissue repair in vertebrates. EMT is also recognized as the crucial event by which cancer cells acquire an invasive phenotype through the activation of specific transcription factors and signalling pathways. Even though glial cells have a mesenchymal phenotype, an EMT-like process tends to exacerbate it during gliomagenesis and progression to more aggressive stages of the disease. Autophagy is an evolutionary conserved degradative process that cells use in order to maintain a proper homeostasis, and defects in autophagy have been associated to several pathologies including cancer. Besides modulating cell resistance or sensitivity to therapy, autophagy also affects the migration and invasion capabilities of tumor cells. Despite this evidence, few papers are present in literature about the involvement of autophagy in EMT-like processes in glioblastoma (GBM) so far. This review summarizes the current understanding of the interplay between autophagy and EMT in cancer, with special regard to GBM model. As the invasive behaviour is a hallmark of GBM aggressiveness, defining a new link between autophagy and EMT can open a novel scenario for targeting these processes in future therapeutical approaches.

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