scholarly journals Regulation of Epithelial-to-Mesenchymal Transition by Alternative Translation Initiation Mechanisms and Its Implications for Cancer Metastasis

2020 ◽  
Vol 21 (11) ◽  
pp. 4075
Author(s):  
Amit Bera ◽  
Stephen M. Lewis
Keyword(s):  
Translation Initiation ◽  
Tumor Metastasis ◽  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Critical Role ◽  
Regulation Of Gene Expression ◽  
Migration And Invasion ◽  
Entry Site ◽  
Internal Ribosome Entry ◽  
Mesenchymal Transition

Translation initiation plays a critical role in the regulation of gene expression for development and disease conditions. During the processes of development and disease, cells select specific mRNAs to be translated by controlling the use of diverse translation initiation mechanisms. Cells often switch translation initiation from a cap-dependent to a cap-independent mechanism during epithelial-to-mesenchymal transition (EMT), a process that plays an important role in both development and disease. EMT is involved in tumor metastasis because it leads to cancer cell migration and invasion, and is also associated with chemoresistance. In this review we will provide an overview of both the internal ribosome entry site (IRES)-dependent and N6-methyladenosine (m6A)-mediated translation initiation mechanisms and discuss how cap-independent translation enables cells from primary epithelial tumors to achieve a motile mesenchymal-like phenotype, which in turn drives tumor metastasis.

scholarly journals Extracellular HSP90α-LRP1 Signaling Promote Pancreatic Cancer Metastasis and Chemoresistance Via Regulating Epithelial-To-Mesenchymal Transition

2021 ◽  
Author(s):  
Nina Xue ◽  
Tingting Du ◽  
Fangfang Lai ◽  
Jing Jin ◽  
Ming Ji ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Epithelial Mesenchymal Transition ◽  
Critical Role ◽  
Density Lipoprotein ◽  
Underlying Mechanism ◽  
Migration And Invasion ◽  
Mesenchymal Transition

Abstract Extracellular heat shock protein 90α (HSP90α) has been reported to promote cancer cell invasion and migration. However, whether pancreatic cancer (PC) cells expressed membrane-bound or secreted HSP90α and its underlying mechanism for PC progression were still unclear. Our study pointed out that highly invasive Capan2 cells has a higher level of secreted HSP90α, rather than membrane HSP90α, compared with those of less invasive PL45 cells. The conditioned medium of Capan2 cells or recombinant HSP90α protein was able to stimulate the migration and invasion of PL45 or capan2 cells, which could be prevented by a neutralizing anti-HSP90α antibody. Furthermore, secreted HSP90α promoted elements of epithelial-mesenchymal transition (EMT) in PL45 cells, including increases in vimentin and snail expressions, decreases in E-cadherin expression and changes in cell shape towards a mesenchymal phenotype, but these phenomena were reversed by anti-HSP90α antibody in Capan2 cells. In addition, high levels of low-density lipoprotein receptor-related protein 1 (LRP1) mRNA were associated with worsened patient survival in pancreatic adenocarcinoma. LRP1 as a receptor of eHSP90α for its stimulatory role of PC cells EMT and metastasis by activating AKT signaling. Down-regulation of LRP1 could promote chemosensitivity to gemcitabine and doxorubicin, but not to topotecan and paclitaxel in Capan2 cells. Therefore, our study reveals a critical role of secreted HSP90α on EMT events and suggests blocking secreted HSP90α underlies an aspect of metastasis and chemoresistance.

scholarly journals Ovalitenone Inhibits the Migration of Lung Cancer Cells via the Suppression of AKT/mTOR and Epithelial-to-Mesenchymal Transition

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 638
Author(s):  
Kittipong Sanookpan ◽  
Nongyao Nonpanya ◽  
Boonchoo Sritularak ◽  
Pithi Chanvorachote
Keyword(s):  
Lung Cancer ◽  
Cell Migration ◽  
Cancer Cells ◽  
Colony Formation ◽  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
A549 Cells ◽  
Lung Cancer Cells ◽  
Migration And Invasion ◽  
Mesenchymal Transition

Cancer metastasis is the major cause of about 90% of cancer deaths. As epithelial-to-mesenchymal transition (EMT) is known for potentiating metastasis, this study aimed to elucidate the effect of ovalitenone on the suppression of EMT and metastasis-related behaviors, including cell movement and growth under detached conditions, and cancer stem cells (CSCs), of lung cancer cells. Methods: Cell viability and cell proliferation were determined by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazo-liumbromide (MTT) and colony formation assays. Cell migration and invasion were analyzed using a wound-healing assay and Boyden chamber assay, respectively. Anchorage-independent cell growth was determined. Cell protrusions (filopodia) were detected by phalloidin-rhodamine staining. Cancer stem cell phenotypes were assessed by spheroid formation. The proteins involved in cell migration and EMT were evaluated by Western blot analysis and immunofluorescence staining. Results: Ovalitenone was used at concentrations of 0–200 μM. While it caused no cytotoxic effects on lung cancer H460 and A549 cells, ovalitenone significantly suppressed anchorage-independent growth, CSC-like phenotypes, colony formation, and the ability of the cancer to migrate and invade cells. The anti-migration activity was confirmed by the reduction of filopodia in the cells treated with ovalitenone. Interestingly, we found that ovalitenone could significantly decrease the levels of N-cadherin, snail, and slug, while it increased E-cadherin, indicating EMT suppression. Additionally, the regulatory signaling of focal adhesion kinase (FAK), ATP-dependent tyrosine kinase (AKT), the mammalian target of rapamycin (mTOR), and cell division cycle 42 (Cdc42) was suppressed by ovalitenone. Conclusions: The results suggest that ovalitenone suppresses EMT via suppression of the AKT/mTOR signaling pathway. In addition, ovalitenone exhibited potential for the suppression of CSC phenotypes. These data reveal the anti-metastasis potential of the compound and support the development of ovalitenone treatment for lung cancer therapy.

The Role of Calcium Signaling in Regulation of Epithelial-Mesenchymal Transition

2020 ◽  
pp. 1-23
Author(s):  
Divya Adiga ◽  
Raghu Radhakrishnan ◽  
Sanjiban Chakrabarty ◽  
Prashant Kumar ◽  
Shama Prasada Kabekkodu
Keyword(s):  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Epithelial Mesenchymal Transition ◽  
Critical Role ◽  
Cancer Therapeutics ◽  
Growth And Survival ◽  
Mesenchymal Transition ◽  
Microenvironmental Factors ◽  
Favorable Clinical Outcome

Despite substantial advances in the field of cancer therapeutics, metastasis is a significant challenge for a favorable clinical outcome. Epithelial to mesenchymal transition (EMT) is a process of acquiring increased motility, invasiveness, and therapeutic resistance by cancer cells for their sustained growth and survival. A plethora of intrinsic mechanisms and extrinsic microenvironmental factors drive the process of cancer metastasis. Calcium (Ca<sup>2+</sup>) signaling plays a critical role in dictating the adaptive metastatic cell behavior comprising of cell migration, invasion, angiogenesis, and intravasation. By modulating EMT, Ca<sup>2+</sup> signaling can regulate the complexity and dynamics of events leading to metastasis. This review summarizes the role of Ca<sup>2+</sup> signal remodeling in the regulation of EMT and metastasis in cancer.

Molecular Characterization of Epithelial to Mesenchymal Transition in Human Prostatic Epithelial Cells

2010 ◽  
Vol 1 (2) ◽  
Author(s):  
Victor K. Lin ◽  
Shih-Ya Wang ◽  
Lanxiao Wu ◽  
Smitha M. Rao ◽  
J. C. Chiao ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Mammary Epithelial Cells ◽  
Critical Role ◽  
Three Dimensional ◽  
Mammary Epithelial ◽  
Mesenchymal Transition ◽  
Enhanced Mobility ◽  
E Cadherin

Epithelial to mesenchymal transition (EMT) has been believed to play a critical role in cancer metastasis. TGFβ has been described as an inducer of EMT in normal mammary epithelial cells by signaling through receptor serine/threonine kinase pathways to regulate epithelial cell plasticity and invasion. In this study, we investigated the EMT cellular responses, including morphologic changes, phenotype switches, invasiveness enhancement, and cellular contraction alteration, in TGFβ stimulated human prostate normal epithelial cells (PZ-HPV-7). Migration of TGFβ treated PZ-HPV-7 cells across matrigel was measured in invasion chambers (8 μm pore size). The cells were treated with or without TGFβ (2 ng/ml) in PrEGM media for 3 days. Immunoblot assay was conducted and it was demonstrated that the induction of vimentin when stimulated by TGFβ was accompanied by a downregulation of E-cadherin, though p-cadherin level was not altered. It was also observed that there was a decrease in cytokaretin 5/6 expression associated with the downregulation of E-cadherin during the induction of EMT. In order to study the cell contraction, three-dimensional collage lattice assay was performed. It was demonstrated that TGFβ-stimulated PZ-HPV-7 cells gained contractility. Our results showed that TGFβ stimulation induced PZ-HPV-7 cells to undergo epithelial to mesenchymal transition. EMT characteristics such as acquisition of mesenchymal markers and loss of epithelial markers were evident in the induction of vimentin and downregulation of E-cadherin and cytokeratins, as well as phenotypic alterations including increased contraction and enhanced mobility were detected.

scholarly journals Vimentin is Required for Tumor Progression and Metastasis in a Mouse Model of Non-Small Cell Lung Cancer

2020 ◽  
Author(s):  
Alexandra L. Berr ◽  
Kristin Wiese ◽  
Gimena dos Santos ◽  
Jennifer M. Davis ◽  
Clarissa M. Koch ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lung Cancer ◽  
Mouse Model ◽  
Lung Adenocarcinoma ◽  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Differential Expression Analysis ◽  
Migration And Invasion ◽  
Mesenchymal Transition ◽  
Lung Cancer Metastasis

AbstractVimentin, a type III intermediate filament, is highly expressed in aggressive epithelial cancers and is associated with increased rates of metastasis. We show that vimentin is causally required for lung cancer metastasis using a genetic mouse model of lung adenocarcinoma (LSL-KrasG12D;Tp53fl/fl, termed KPV+/+) crossed with vimentin-null mice (thereby creating KPV−/− mice). Both KPV+/+ and KPV−/− mice developed lung tumors, yet KPV−/− mice had delayed tumorigenesis and prolonged survival. KPV+/+ cells implanted in the flank metastasized to the lung while KPV−/− cells did not, providing additional evidence that vimentin is required for metastasis. Differential expression analysis of RNA-seq data demonstrated that KPV−/− cells had suppressed expression of genes that drive epithelial-to-mesenchymal transition, migration, and invasion, processes that are critical to the metastatic cascade. Integrative metabolomic and transcriptomic analysis revealed altered glutaminolysis, with KPV−/− cells accumulating glutathione, leading to impaired cell motility in response to oxidative stress. Together, these results show that loss of vimentin impairs epithelial-to-mesenchymal transition and regulation of the oxidative stress response, resulting in decreased metastasis in murine lung adenocarcinoma.

scholarly journals Identification of Cardiac Glycoside Molecules as Inhibitors of c-Myc IRES-Mediated Translation

2012 ◽  
Vol 18 (4) ◽  
pp. 407-419 ◽  
Author(s):  
Marie-Cecile Didiot ◽  
Jeffrey Hewett ◽  
Thibault Varin ◽  
Felix Freuler ◽  
Douglas Selinger ◽  
...  
Keyword(s):  
Cell Viability ◽  
Translation Initiation ◽  
Cardiac Glycosides ◽  
Critical Role ◽  
Mrna Translation ◽  
Cancer Therapeutics ◽  
Entry Site ◽  
Internal Ribosome Entry ◽  
Translational Initiation ◽  
Click Beetle

Translation initiation is a fine-tuned process that plays a critical role in tumorigenesis. The use of small molecules that modulate mRNA translation provides tool compounds to explore the mechanism of translational initiation and to further validate protein synthesis as a potential pharmaceutical target for cancer therapeutics. This report describes the development and use of a click beetle, dual luciferase cell-based assay multiplexed with a measure of compound toxicity using resazurin to evaluate the differential effect of natural products on cap-dependent or internal ribosome entry site (IRES)–mediated translation initiation and cell viability. This screen identified a series of cardiac glycosides as inhibitors of IRES-mediated translation using, in particular, the oncogene mRNA c-Myc IRES. Treatment of c-Myc–dependent cancer cells with these compounds showed a decrease in c-Myc protein associated with a significant modulation of cell viability. These findings suggest that inhibition of IRES-mediated translation initiation may be a strategy to inhibit c-Myc–driven tumorigenesis.

scholarly journals High intratumoral expression of eIF4A1 promotes epithelial-to-mesenchymal transition and predicts unfavorable prognosis in gastric cancer

2020 ◽  
Vol 52 (3) ◽  
pp. 310-319 ◽  
Author(s):  
Chanchan Gao ◽  
Xinyin Guo ◽  
Anwei Xue ◽  
Yuanyuan Ruan ◽  
Hongshan Wang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Cells ◽  
Translation Initiation ◽  
Epithelial To Mesenchymal Transition ◽  
Protein Translation ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Migration And Invasion ◽  
Gastric Cancer Cells ◽  
Mesenchymal Transition

Abstract Gastric cancer is an important health problem, being the fifth most common cancer and the third leading cause of cancer-related death worldwide. Aberrant protein translation contributes to the oncogenesis and development of cancers, and upregulation of translation initiation factor eIF4A1 has been observed in several kinds of malignancies. However, the role of eIF4A1 in gastric cancer progression remains unclear. In this study, we found that the expression of eIF4A1, a component of translation initiation complex, was increased in gastric cancer. High expression of eIF4A1 was positively associated with poor tumor differentiation, late T stage, lymph node metastasis, advanced TNM stage, and poor prognosis in patients with gastric cancer. Overexpression of eIF4A1 promoted the migration and invasion of gastric cancer cells in vitro and enhanced tumor metastasis in nude mice model. Mechanism studies revealed that eIF4A1 induced epithelial-to-mesenchymal transition (EMT) of gastric cancer cells through driving the translation of SNAI1 mRNA. Together, these findings indicate that eIF4A1 promotes EMT and metastasis of gastric cancer and suggest that eIF4A1 is a potential target for the adjuvant therapy for gastric cancer patients.

scholarly journals Noncoding RNAs in Tumor Epithelial-to-Mesenchymal Transition

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Ching-Wen Lin ◽  
Pei-Ying Lin ◽  
Pan-Chyr Yang
Keyword(s):  
Signaling Pathways ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Regulation Of Gene Expression ◽  
Noncoding Rnas ◽  
Protein Translation ◽  
Gene Expressions ◽  
Mesenchymal Transition

Epithelial-derived tumor cells acquire the capacity for epithelial-to-mesenchymal transition (EMT), which enables them to invade adjacent tissues and/or metastasize to distant organs. Cancer metastasis is the main cause of cancer-related death. Molecular mechanisms involved in the switch from an epithelial phenotype to mesenchymal status are complicated and are controlled by a variety of signaling pathways. Recently, a set of noncoding RNAs (ncRNAs), including miRNAs and long noncoding RNAs (lncRNAs), were found to modulate gene expressions at either transcriptional or posttranscriptional levels. These ncRNAs are involved in EMT through their interplay with EMT-related transcription factors (EMT-TFs) and EMT-associated signaling. Reciprocal regulatory interactions between lncRNAs and miRNAs further increase the complexity of the regulation of gene expression and protein translation. In this review, we discuss recent findings regarding EMT-regulating ncRNAs and their associated signaling pathways involved in cancer progression.

scholarly journals TDO2 Promotes the EMT of Hepatocellular Carcinoma Through Kyn-AhR Pathway

2021 ◽  
Vol 10 ◽  
Author(s):  
Lei Li ◽  
Tao Wang ◽  
Shanbao Li ◽  
Zhengqian Chen ◽  
Junyi Wu ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Aryl Hydrocarbon Receptor ◽  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Migration And Invasion ◽  
Mesenchymal Transition ◽  
Aryl Hydrocarbon ◽  
Hcc Cells

Tryptophan 2,3-dioxygenase (TDO2), an enzyme involved in tryptophan (Trp) metabolism has been linked with some malignant traits of various cancers. Kyn, the main product of Trp metabolism pathway catalyzed by TDO2 and indoleamine 2,3-dioxygenase (IDO) in tumor cells, was also demonstrated to activate aryl hydrocarbon receptor (AhR), which may regulate cancer growth and invasion in some malignancies. However, whether TDO2 participates in the metastasis and invasion of HCC has not been explored before. The underlying mechanism played by TDO2 in this process still requires further investigation. Here, we demonstrated that overexpression of TDO2 correlates with advanced stage or malignant traits in HCC patients. Knockdown or inhibition of TDO2 suppressed the migration and invasion of HCC cells in vitro and in vivo. Epithelial to mesenchymal transition (EMT) is an essential program happened in the initial phase of cancer metastasis. We found that in HCC cells, TDO2 promoted the EMT process evidenced by altered levels of biomarkers for EMT. Mechanically, TDO2 regulated the Kyn production in HCC cell via activated aryl hydrocarbon receptor (AhR). Together, these results indicate that TDO2 promotes the EMT of hepatocellular carcinoma through activating Kyn-AhR pathway, thereby participating in the metastasis and invasion of HCC.

Mnt represses epithelial identity to promote Epithelial to Mesenchymal Transition

2021 ◽  
Author(s):  
Deborah P. Lavin ◽  
Leila Abassi ◽  
Mohammed Inayatullah ◽  
Vijay K. Tiwari
Keyword(s):  
Epithelial Cells ◽  
Cell Fate ◽  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Mammary Epithelial Cells ◽  
Morphological Changes ◽  
Critical Role ◽  
Chromatin Accessibility ◽  
Mammary Epithelial ◽  
Mesenchymal Transition

The multi-step process of epithelial to mesenchymal transition (EMT), whereby static epithelial cells become migratory mesenchymal cells, plays a critical role during various developmental contexts, wound healing, and pathological conditions such as cancer metastasis. Despite the established function of basic helix-loop-helix (bHLH) transcription factors (TFs) in cell-fate determination, only a few have been examined for their role in EMT. Here, using transcriptome analysis of distinct stages during stepwise progression of TGFβ-induced EMT in mammary epithelial cells, we revealed distinct categories of bHLH TFs that show differential expression kinetics during EMT. Using a siRNA-mediated functional screen for bHLH TFs during EMT, we found Max network transcription repressor (MNT) to be essential for EMT in mammary epithelial cells. We show that the depletion of MNT blocks TGFβ-induced morphological changes during EMT, and this is accompanied by de-repression of a large number of epithelial genes. We show that MNT mediates the repression of epithelial identity genes during EMT by recruiting HDAC1 and mediating the loss of H3K27ac and chromatin accessibility. Lastly, we show that MNT is expressed at higher levels in EMT-High breast cancer cells and is required for their migration. Taken together, these findings establish MNT as a critical regulator of cell-fate changes during mammary EMT.

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