scholarly journals Activation of a Ductal-to-Endocrine Transdifferentiation Transcriptional Program in the Pancreatic Cancer Cell Line PANC-1 Is Controlled by RAC1 and RAC1b through Antagonistic Regulation of Stemness Factors

Cancers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 5541
Author(s):  
Paula Marie Schmidtlein ◽  
Clara Volz ◽  
Alexander Hackel ◽  
Isabel Thürling ◽  
Darko Castven ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Epithelial Mesenchymal Transition ◽  
Ectopic Expression ◽  
Pancreatic Cancer Cell Line ◽  
Therapy Resistance ◽  
Small Gtpase ◽  
Dominant Negative ◽  
Transcriptional Program ◽  
Mesenchymal Transition ◽  
Insulin Producing Cells

Epithelial–mesenchymal transition (EMT) is a driving force for tumor growth, metastatic spread, therapy resistance, and the generation of cancer stem cells (CSCs). However, the regained stem cell character may also be exploited for therapeutic conversion of aggressive tumor cells to benign, highly differentiated cells. The PDAC-derived quasimesenchymal-type cell lines PANC-1 and MIA PaCa-2 have been successfully transdifferentiated to endocrine precursors or insulin-producing cells; however, the underlying mechanism of this increased plasticity remains elusive. Given its crucial role in normal pancreatic endocrine development and tumor progression, both of which involve EMT, we analyzed here the role of the small GTPase RAC1. Ectopic expression in PANC-1 cells of dominant negative or constitutively active mutants of RAC1 activation blocked or enhanced, respectively, the cytokine-induced activation of a ductal-to-endocrine transdifferentiation transcriptional program (deTDtP) as revealed by induction of the NEUROG3, INS, SLC2A2, and MAFA genes. Conversely, ectopic expression of RAC1b, a RAC1 splice isoform and functional antagonist of RAC1-driven EMT, decreased the deTDtP, while genetic knockout of RAC1b dramatically increased it. We further show that inhibition of RAC1 activation attenuated pluripotency marker expression and self-renewal ability, while depletion of RAC1b dramatically enhanced stemness features and clonogenic potential. Finally, rescue experiments involving pharmacological or RNA interference-mediated inhibition of RAC1 or RAC1b, respectively, confirmed that both RAC1 isoforms control the deTDtP in an opposite manner. We conclude that RAC1 and RAC1b antagonistically control growth factor-induced activation of an endocrine transcriptional program and the generation of CSCs in quasimesenchymal PDAC cells. Our results have clinical implications for PDAC patients, who in addition to eradication of tumor cells have a need for replacement of insulin-producing cells.

scholarly journals TGF-β and the Smad Signaling Pathway Support Transcriptomic Reprogramming during Epithelial-Mesenchymal Cell Transition

2005 ◽  
Vol 16 (4) ◽  
pp. 1987-2002 ◽  
Author(s):  
Ulrich Valcourt ◽  
Marcin Kowanetz ◽  
Hideki Niimi ◽  
Carl-Henrik Heldin ◽  
Aristidis Moustakas
Keyword(s):  
Target Genes ◽  
Transforming Growth Factor ◽  
Epithelial Mesenchymal Transition ◽  
Smooth Muscle Actin ◽  
Expression Patterns ◽  
Ectopic Expression ◽  
Dominant Negative ◽  
Type I ◽  
Mesenchymal Transition ◽  
Smad Signaling

Epithelial-mesenchymal transition (EMT) contributes to normal tissue patterning and carcinoma invasiveness. We show that transforming growth factor (TGF)-β/activin members, but not bone morphogenetic protein (BMP) members, can induce EMT in normal human and mouse epithelial cells. EMT correlates with the ability of these ligands to induce growth arrest. Ectopic expression of all type I receptors of the TGF-β superfamily establishes that TGF-β but not BMP pathways can elicit EMT. Ectopic Smad2 or Smad3 together with Smad4 enhanced, whereas dominant-negative forms of Smad2, Smad3, or Smad4, and wild-type inhibitory Smad7, blocked TGF-β–induced EMT. Transcriptomic analysis of EMT kinetics identified novel TGF-β target genes with ligand-specific responses. Using a TGF-β type I receptor that cannot activate Smads nor induce EMT, we found that Smad signaling is critical for regulation of all tested gene targets during EMT. One such gene, Id2, whose expression is repressed by TGF-β1 but induced by BMP-7 is critical for regulation of at least one important myoepithelial marker, α-smooth muscle actin, during EMT. Thus, based on ligand-specific responsiveness and evolutionary conservation of the gene expression patterns, we begin deciphering a genetic network downstream of TGF-β and predict functional links to the control of cell proliferation and EMT.

scholarly journals Context-dependent EMT programs in cancer metastasis

2019 ◽  
Vol 216 (5) ◽  
pp. 1016-1026 ◽  
Author(s):  
Nicole M. Aiello ◽  
Yibin Kang
Keyword(s):  
Tumor Cells ◽  
Cell Fate ◽  
Cancer Metastasis ◽  
Developmental Process ◽  
Epithelial Mesenchymal Transition ◽  
Therapy Resistance ◽  
Adherent Cells ◽  
Mesenchymal Transition ◽  
Functional Consequences ◽  
Tumor Types

Epithelial–mesenchymal transition (EMT) is a developmental process whereby stationary, adherent cells acquire the ability to migrate. EMT is critical for dramatic cellular movements during embryogenesis; however, tumor cells can reactivate EMT programs, which increases their aggressiveness. In addition to motility, EMT is associated with enhanced stem cell properties and drug resistance; thus it can drive metastasis, tumor recurrence, and therapy resistance in the context of cancer. However, the precise requirements for EMT in metastasis have not been fully delineated, with different tumor types relying on discrete EMT effectors. Most tumor cells do not undergo a full EMT, but rather adopt some qualities of mesenchymal cells and maintain some epithelial characteristics. Emerging evidence suggests that partial EMT can drive distinct migratory properties and enhance the epithelial-mesenchymal plasticity of cancer cells as well as cell fate plasticity. This review discusses the diverse regulatory mechanisms and functional consequences of EMT, with an emphasis on the importance of partial EMT.

scholarly journals Association of the Epithelial–Mesenchymal Transition (EMT) with Cisplatin Resistance

2020 ◽  
Vol 21 (11) ◽  
pp. 4002 ◽  
Author(s):  
Milad Ashrafizadeh ◽  
Ali Zarrabi ◽  
Kiavash Hushmandi ◽  
Mahshad Kalantari ◽  
Reza Mohammadinejad ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Epithelial Mesenchymal Transition ◽  
Therapy Resistance ◽  
Nuclear Factor Κb ◽  
Molecular Pathways ◽  
Cancer Resistance ◽  
Mesenchymal Transition ◽  
The Impact

Therapy resistance is a characteristic of cancer cells that significantly reduces the effectiveness of drugs. Despite the popularity of cisplatin (CP) as a chemotherapeutic agent, which is widely used in the treatment of various types of cancer, resistance of cancer cells to CP chemotherapy has been extensively observed. Among various reported mechanism(s), the epithelial–mesenchymal transition (EMT) process can significantly contribute to chemoresistance by converting the motionless epithelial cells into mobile mesenchymal cells and altering cell–cell adhesion as well as the cellular extracellular matrix, leading to invasion of tumor cells. By analyzing the impact of the different molecular pathways such as microRNAs, long non-coding RNAs, nuclear factor-κB (NF-ĸB), phosphoinositide 3-kinase-related protein kinase (PI3K)/Akt, mammalian target rapamycin (mTOR), and Wnt, which play an important role in resistance exhibited to CP therapy, we first give an introduction about the EMT mechanism and its role in drug resistance. We then focus specifically on the molecular pathways involved in drug resistance and the pharmacological strategies that can be used to mitigate this resistance. Overall, we highlight the various targeted signaling pathways that could be considered in future studies to pave the way for the inhibition of EMT-mediated resistance displayed by tumor cells in response to CP exposure.

Effect of Annexins Translocated in Extracellular Vesicles on Tumorigenesis

2020 ◽  
Vol 20 ◽  
Author(s):  
Qionghui Wu ◽  
Haidong Wei ◽  
Wenbo Meng ◽  
Xiaodong Xie ◽  
Zhenchang Zhang ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Extracellular Vesicles ◽  
Immune Cell ◽  
Epithelial Mesenchymal Transition ◽  
Main Role ◽  
Tumor Cell Adhesion ◽  
Mesenchymal Transition ◽  
Calcium Dependent ◽  
Tumor Neovascularization

: Annexin, a calcium-dependent phospholipid binding protein, can affect tumor cell adhesion, proliferation, apoptosis, invasion and metastasis, as well as tumor neovascularization in different ways. Recent studies have shown that annexin exists not only as an intracellular protein in tumor cells, but also in different ways to be secret outside the cell as a “crosstalk” tool for tumor cells and tumor microenvironment, thus playing an important role in the development of tumors, such as participating in epithelial-mesenchymal transition, regulating immune cell behavior, promoting neovascularization and so on. The mechanism of annexin secretion in the form of extracellular vesicles and its specific role is still unclear. This paper summarizes the main role of annexin secreted into the extracellular space in the form of extracellular vesicles in tumorigenesis and drug resistance and analyzes its possible mechanism.

scholarly journals Hypoxia-Induced Cancer Cell Responses Driving Radioresistance of Hypoxic Tumors: Approaches to Targeting and Radiosensitizing

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1102
Author(s):  
Alexander E. Kabakov ◽  
Anna O. Yakimova
Keyword(s):  
Heat Shock ◽  
Tumor Cells ◽  
Cancer Cell ◽  
Epithelial Mesenchymal Transition ◽  
Liver Tumors ◽  
Oxygen Deficiency ◽  
Transarterial Embolization ◽  
Antiangiogenic Therapy ◽  
Adaptation To Hypoxia ◽  
Mesenchymal Transition

Within aggressive malignancies, there usually are the “hypoxic zones”—poorly vascularized regions where tumor cells undergo oxygen deficiency through inadequate blood supply. Besides, hypoxia may arise in tumors as a result of antiangiogenic therapy or transarterial embolization. Adapting to hypoxia, tumor cells acquire a hypoxia-resistant phenotype with the characteristic alterations in signaling, gene expression and metabolism. Both the lack of oxygen by itself and the hypoxia-responsive phenotypic modulations render tumor cells more radioresistant, so that hypoxic tumors are a serious challenge for radiotherapy. An understanding of causes of the radioresistance of hypoxic tumors would help to develop novel ways for overcoming this challenge. Molecular targets for and various approaches to radiosensitizing hypoxic tumors are considered in the present review. It is here analyzed how the hypoxia-induced cellular responses involving hypoxia-inducible factor-1, heat shock transcription factor 1, heat shock proteins, glucose-regulated proteins, epigenetic regulators, autophagy, energy metabolism reprogramming, epithelial–mesenchymal transition and exosome generation contribute to the radioresistance of hypoxic tumors or may be inhibited for attenuating this radioresistance. The pretreatments with a multitarget inhibition of the cancer cell adaptation to hypoxia seem to be a promising approach to sensitizing hypoxic carcinomas, gliomas, lymphomas, sarcomas to radiotherapy and, also, liver tumors to radioembolization.

scholarly journals EHF suppresses cancer progression by inhibiting ETS1-mediated ZEB expression

Oncogenesis ◽  
2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Kaname Sakamoto ◽  
Kaori Endo ◽  
Kei Sakamoto ◽  
Kou Kayamori ◽  
Shogo Ehata ◽  
...  
Keyword(s):  
Cancer Progression ◽  
Epithelial Mesenchymal Transition ◽  
Short Form ◽  
Dominant Negative ◽  
Mesenchymal Transition ◽  
Exon 1 ◽  
Ets Transcription Factor ◽  
Ets Homologous Factor ◽  
Form Variant

AbstractETS homologous factor (EHF) belongs to the epithelium-specific subfamily of the E26 transformation-specific (ETS) transcription factor family. Currently, little is known about EHF’s function in cancer. We previously reported that ETS1 induces expression of the ZEB family proteins ZEB1/δEF1 and ZEB2/SIP1, which are key regulators of the epithelial–mesenchymal transition (EMT), by activating the ZEB1 promoters. We have found that EHF gene produces two transcript variants, namely a long form variant that includes exon 1 (EHF-LF) and a short form variant that excludes exon 1 (EHF-SF). Only EHF-SF abrogates ETS1-mediated activation of the ZEB1 promoter by promoting degradation of ETS1 proteins, thereby inhibiting the EMT phenotypes of cancer cells. Most importantly, we identified a novel point mutation within the conserved ETS domain of EHF, and found that EHF mutations abolish its original function while causing the EHF protein to act as a potential dominant negative, thereby enhancing metastasis in vivo. Therefore, we suggest that EHF acts as an anti-EMT factor by inhibiting the expression of ZEBs, and that EHF mutations exacerbate cancer progression.

scholarly journals Epithelial-Mesenchymal Transition and MicroRNAs in Colorectal Cancer Chemoresistance to FOLFOX

Pharmaceutics ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 75
Author(s):  
Paula I. Escalante ◽  
Luis A. Quiñones ◽  
Héctor R. Contreras
Keyword(s):  
Colorectal Cancer ◽  
Tumor Cells ◽  
Methylenetetrahydrofolate Reductase ◽  
Epithelial Mesenchymal Transition ◽  
Late Onset ◽  
Dihydropyrimidine Dehydrogenase ◽  
Acquired Resistance ◽  
Potential Effect ◽  
Mesenchymal Transition ◽  
Folfox Chemotherapy

The FOLFOX scheme, based on the association of 5-fluorouracil and oxaliplatin, is the most frequently indicated chemotherapy scheme for patients diagnosed with metastatic colorectal cancer. Nevertheless, development of chemoresistance is one of the major challenges associated with this disease. It has been reported that epithelial-mesenchymal transition (EMT) is implicated in microRNA-driven modulation of tumor cells response to 5-fluorouracil and oxaliplatin. Moreover, from pharmacogenomic research, it is known that overexpression of genes encoding dihydropyrimidine dehydrogenase (DPYD), thymidylate synthase (TYMS), methylenetetrahydrofolate reductase (MTHFR), the DNA repair enzymes ERCC1, ERCC2, and XRCC1, and the phase 2 enzyme GSTP1 impair the response to FOLFOX. It has been observed that EMT is associated with overexpression of DPYD, TYMS, ERCC1, and GSTP1. In this review, we investigated the role of miRNAs as EMT promotors in tumor cells, and its potential effect on the upregulation of DPYD, TYMS, MTHFR, ERCC1, ERCC2, XRCC1, and GSTP1 expression, which would lead to resistance of CRC tumor cells to 5-fluorouracil and oxaliplatin. This constitutes a potential mechanism of epigenetic regulation involved in late-onset of acquired resistance in mCRC patients under FOLFOX chemotherapy. Expression of these biomarker microRNAs could serve as tools for personalized medicine, and as potential therapeutic targets in the future.

Galectin-3: A factotum in carcinogenesis bestowing an archery for prevention

Tumor Biology ◽  
2021 ◽  
Vol 43 (1) ◽  
pp. 77-96
Author(s):  
T. Jeethy Ram ◽  
Asha Lekshmi ◽  
Thara Somanathan ◽  
K. Sujathan
Keyword(s):  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Cancer Metastasis ◽  
Epithelial Mesenchymal Transition ◽  
Therapy Resistance ◽  
Cellular Level ◽  
Clinical Samples ◽  
Innovative Strategy ◽  
Mesenchymal Transition ◽  
Galectin 3

Cancer metastasis and therapy resistance are the foremost hurdles in oncology at the moment. This review aims to pinpoint the functional aspects of a unique multifaceted glycosylated molecule in both intracellular and extracellular compartments of a cell namely galectin-3 along with its metastatic potential in different types of cancer. All materials reviewed here were collected through the search engines PubMed, Scopus, and Google scholar. Among the 15 galectins identified, the chimeric gal-3 plays an indispensable role in the differentiation, transformation, and multi-step process of tumor metastasis. It has been implicated in the molecular mechanisms that allow the cancer cells to survive in the intravascular milieu and promote tumor cell extravasation, ultimately leading to metastasis. Gal-3 has also been found to have a pivotal role in immune surveillance and pro-angiogenesis and several studies have pointed out the importance of gal-3 in establishing a resistant phenotype, particularly through the epithelial-mesenchymal transition process. Additionally, some recent findings suggest the use of gal-3 inhibitors in overcoming therapeutic resistance. All these reports suggest that the deregulation of these specific lectins at the cellular level could inhibit cancer progression and metastasis. A more systematic study of glycosylation in clinical samples along with the development of selective gal-3 antagonists inhibiting the activity of these molecules at the cellular level offers an innovative strategy for primary cancer prevention.

scholarly journals The Role of microRNAs in Cholangiocarcinoma

2021 ◽  
Vol 22 (14) ◽  
pp. 7627
Author(s):  
Tingting Shi ◽  
Asahiro Morishita ◽  
Hideki Kobara ◽  
Tsutomu Masaki
Keyword(s):  
Cell Cycle Progression ◽  
Target Genes ◽  
Epithelial Mesenchymal Transition ◽  
Survival Rates ◽  
Therapy Resistance ◽  
Resistance Mechanisms ◽  
Mesenchymal Transition ◽  
Diagnosis And Prognosis ◽  
Related Risk

Cholangiocarcinoma (CCA), an aggressive malignancy, is typically diagnosed at an advanced stage. It is associated with dismal 5-year postoperative survival rates, generating an urgent need for prognostic and diagnostic biomarkers. MicroRNAs (miRNAs) are a class of non-coding RNAs that are associated with cancer regulation, including modulation of cell cycle progression, apoptosis, metastasis, angiogenesis, autophagy, therapy resistance, and epithelial–mesenchymal transition. Several miRNAs have been found to be dysregulated in CCA and are associated with CCA-related risk factors. Accumulating studies have indicated that the expression of altered miRNAs could act as oncogenic or suppressor miRNAs in the development and progression of CCA and contribute to clinical diagnosis and prognosis prediction as potential biomarkers. Furthermore, miRNAs and their target genes also contribute to targeted therapy development and aid in the determination of drug resistance mechanisms. This review aims to summarize the roles of miRNAs in the pathogenesis of CCA, their potential use as biomarkers of diagnosis and prognosis, and their utilization as novel therapeutic targets in CCA.

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